0 O N T E N 2 I PAR IA Specific Gravitios; Boil;ng and Melting Points; and Ohemical Formula. F IR 3 T U P2 L EXE N T i 0 AR I Spocific Gravities, Bo-il'ng Pointo, and iel ting Point s. P ART I I A Table of 3paocific Hoats for S3olid3 and Liquid,. PART I I Tables of Expan3ion by aeat for Solids and Liqui'3s. PAR T Iv Atomic We igh t Dot 3 rminat i ons PART V. A Recalcul.tion of'the Atomic Wcights. S3ITHISONIAN MISCELLANEOUS COLLECTIONS. 255 THE CONSTANTS OF NATURE. PART I. SPECIFIC GRAVITIES; BOILING AND MELTING POINTS; AND CHEMICAL FORMULA. CO31PILED IBY FRANK WIGGLESWORTHI CLARKE, S.B. WASHINGTON, D.C. PUBLISHED BY THE SMITHSONIAN INSTITUTION. DECEMBER, 1873. ADVE RT ISE MEN T. THE Smithsonian Institution has long had in contemplation the publication of a series of " Constants of Nature," and has accepted the following work as the first part of such a series. Other parts will be published in succession as soon as the matter for them may be obtained and the finances of the Institution will warrant. The present work was referred for critical examination to Professors Joy and Chandler of Columbia College, New York, and has been published on their recommendation. JOSEPH HENRY, Secretary S. L WASHINGTON, D. C., December, 1873. ELECTROTYPED BY MACKELLAR, SMITHS, & JORDAN, PHILADELPHIA. COLLINS, PRINTER. TABLE OF CONTENTS. PAGE. 1.-INTRODUCTION............. 1 2.-LIST OF IMPORTANT PAPERS.. 4 3. —EXPLANATORY NOTES............10 4.-TABLE OF SPECIFIC GRAVITIES, BOILING POINTS AND MELTING POINTS. 13 I.-ELEMENTARY SUBSTANCES...........13 II.-INORGANIC FLUORIDES. 29 III.-INORGANIC CHLORIDES.......... 30 1st. Anhydrous Simple Chlorides..30 2d. Hydrated Simple Chlorides.. 35 3d. Anhydrous Double Chlorides. 36 4th. Hydrated Double Chlorides.. 37 5th. Oxy- and Sulpho-Chlorides. 37 6th. Ammonio-Chlorides...39 IV.-INORGANIC BROMIDES. 39 1st. Anhydrous Simple Bromides........ 39 2d. Hydrated, Double, Oxy- and Sulpho-Bromides. 41 V.-INORGANIC IODIDES............41 1st. Anhydrous Simple Iodides. 41 2d. Hydrated, and Double Iodides........43 VI.-INORGANIC CHLOROBROMIDES, CHLORIODIDES AND BROMIODIDES... 43 VII.-INORGANIC OXIDES..44 1st. Simple Oxides. 44 2d. Double Oxides...57 VIII.-INORGANIC SULPHIDES. 59 1st. Simple Sulphides.......... 59 2d. Sulpharsenites, Sulpharsenates. Sulphantimonites Sulphobismuthites. 63 3d. Miscellaneous Double and Triple Sulphides. 64 111 iv CONTENTS. PAGE. IX.-INORGANIC SELENIDES.. 64 X.-INORGANIC TELLURIDES........ 65 XI.-INORGANIC PHOSPHIDES. 66 XII.-INORGANIC ARSENIDES...........66 XIII.-INORGANIC ANTIMONIDES.....'... 67 XIV.-SULPHIDES WITH OXIDES, ARSENIDES, OR ANTIMIONIDE.... 68 XV.-BORIDES, SILICIDES, &C. 68 XVI.-HYDRATES.............68 XVII.-CHLORATES AND PERCHLORATES. 71 XVIII.-BRomIATES AND IODATES....... 71 XIX. —SULPHITES AND HYPOSULPHITES..... 71 XX.-SULPHATES..72 1st. Anhydrous Simple Sulphates. 72 2d. Hydrated Simple Sulphates....75 3d. Anhydrous Double Sulphates. 77 4th. Hydrated Double Sulphates.. 78 5th. Basic, and Amnmonio-Sulphates. 80 XXI.-SELENITES AND SELENATES..........81 XXII.-CHROMATES. 81 XXIII.-'IANGANATES AND PERMIANGANATES..82 XXIV.-MOLYBDATES. 82 XXV.-TUNGSTATES..83 XXVI-BORATES.. 84 XXTII. —NITRATES...........84 1st. Anhydrous Simple Nitrates. 84 2d. Hydrated Nitrates.. 87 3d. Basic and Ammonio-Nitrates. 88 XXVIII.-PHOSPHATES............88 1st. Anhydrous Orthophosphates. 88 2d. Hydrated Orthophosphates..89 3d. Pyrophosphates. 91 XXIX.- VANADATES...91 XXX.-ARSENITES AND ARSENATES. 92 1st. Anhydrous Arsenites and Arsenates. 92 2d. Hydrated Arsenates. 92 XXXI. —ANTI.MONITES AND ANTIMIONATES.93 CONTENTS. V PAGE. XXXII.-CARBONATES............ 93 1st. Anhydrous Simple Carbonates..93 2d. Hydrated Simple Carbonates. 96 3d. Anhydrous Double Carbonates. 96 4th. Hydrated Double Carbonates, and Basic Carbonates. 97 XXXIII.-SILICATES........... 98 1st. Anhydrous Silicates........ 98 2d. Hydrated Silicates.. 100 XXXIV.-STANNATES AND TITANATES. 101 XXXV.-SILICOFLORIDES............ 101 XXXVI.-CYANIDES AND CYANATES.. 101 1st. Simple Cyanides and Cyanates........ 101 2d. Compound Cyanides.. 102 XXXVII.-MISCELLANEOUS INORGANIC COMPOUNDS.. 102 XXXVIII.-ALLOYS........... 105 1st. Alloys containing but two metals........ 105 2d. Alloys containing more than two metals. 118 XXXIX.-HYDROCARBONS. 119 1st. Series of Alcohol Radicles. 119 2d. Hydrides of Alcohol Radicles. 120 3d. Methylene Series...... 121 4th. Benzol Series. 123 5th. C10 H16 and'its Isomers. 127 6th. Miscellaneous Hydrocarbons.. 130 XL.-COMPOUNDS CONTAINING C, H, AND O..133 1st. Alcohols of the Ethylic Series. 133 2d. Oxides of the Ethylic Series. 137 3d. Acids of the Formic Series. 138 4th. Anhydrides of the Formic Series. 142 5th. Ethers of the Series Cn H2,,... 143 6th. Aldehydes of the Series C,. H2. 0.. 151 7th. Acetones of the Series C,. H2,,. O. 153 8th. Oxides of the Ethylene Series. 155 9th. Glycols..155 10th. Miscellaneous Compounds of the Ethylene Series... 156 11th. Acids. Lactic and Oxalic Series........ 157 12th. Carbonates, Lactates, and Leucates, of the Ethyl Series... 158 13th. Oxalates, Succinates, &c., of the Ethyl Series.... 159'14th. Compounds of Allyl and Diallyl. 160 15th. Glycerine, the Glycerides, and Allied Compounds.... 161 Vi CONTENTS. PAGE. 16th. Saccharine, Starchy, and Gummy Bodies. 163 17th. Miscellaneous Acids. 164 18th. Miscellaneous Ethers of the Ethyl Series.... 166 19th. Miscellaneous Compounds. 169 XLI. —CoIPOUNDS CONTAINING C, H, AND N.. 175 1st. Cyanides of the Ethyl Series..... 175 2d. Amines of the Ethyl Series. 175 3d. Bases of the Aniline Series. 177 4th. Bases of the Pyridine Series. 178 5th. Miscellaneous Compounds.. 178 XLII.-COMPOUNDS CONTAINING C, H, N, AND 0. SO180 1st. Nitrites and Nitrates of the Ethyl Series..... 180 2d. Nitro-Substitution Compounds. 181 3d. Miscellaneous Compounds. 182 XLIII.-METALLIC SALTS OF ORGANIC ACIDS. 183 Formates, Acetates, Oxalates, Succinates, Tartrates, Racemates, Malates, Picrates, Hippurates, &c. 183 XLIV. —CoIMPOUNDS CONTAINING C, H, AND C1. INCLUDING THE CHLORIDES OF CARBON PRODUCED BY SUBSTITUTION FROM ORGANIC BODIES. 186 Ist. Chlorides of the Ethyl Series.......186 2d. Chlorides of the Ethylene Series. 188 3d. Substitution Derivatives of the two preceding Series... 188 4th. Derivatives of the Benzol Series, including Isomers. 191 5th. Miscellaneous Compounds. 194 XLV.-COMPOUNDS CONTAINING C, H, O. C1, or C, 0, C1.. 195 1st. Substitution Compounds......... 195 2d. Chlorhydrins..198 3d. Miscellaneous Compounds.. 199 XLVI. —COMPOUNDS CONTAINING C, C1, N; C, H, C1, N; C, C1, N, O; or, C, H, C1, N, 0. 200 XLVII. —COMPOUNDS CONTAINING C, H, AND Br.. 201 1st. Bromides of the Ethyl Series........ 201 2d. Bromides of the Ethylene Series...202 3d. Miscellaneous Compounds. 203 XLVIII.-COMPOUNDS CONTAINING C, H, Br. 0; C, Br, N, 0; or C, H, N, Br.. 206 XLIX.-COMPOUNDS CONTAINING BOTH CHLORINE AND BROMINE... 207 L.-COMPOUNDS CONTAINING C, H, AND I.. 208 1st. Iodides of the Ethyl Series. 208 2d. Miscellaneous Compounds.. 211 CONTENTS. v'11 PAGE. LI.-COMPOUNDS CONTAINING C, H, I, AND 0. 212 LII.-COMPOUNDS CONTAINING BOTH CHLORINE AND IODINE, OR, BROMINE AND IODINE.......212 LIII.-ORGANIC COMPOUNDS CONTAINING SULPIIUR..... 213 1st. Compounds containing C, H, and S..213 2d. Compounds containing C, H, S, and 0. 215 3d. Sulphur Compounds containing Nitrogen. 216 4th. Chlorinated Sulphur Compounds. 217 LIV.-ORGANIC COMPOUNDS OF SELENIUM AND TELLURIUM.... 218 LV.-ORGANIC COMPOUNDS CONTAINING PHOSPIIORUS. 218 LVI.-ORGANIC COMPOUNDS CONTAINING BORON. 219 LVII. —ORGANIC COMPOUNDS CONTAINING SILICON. 220 LVIII.-ORGANIC COMPOUNDS OF T1, Pb, Zn, Hg, or Al. 221 LIX.-ORGANIC COMPOUNDS CONTAINING As, Sb, or Bi..... 222 LX.-ORGANIC COMPOUNDS OF TIN.......... 223 LXI.-MISCELLANEOUS ORGANIC COMPOUNDS... 224 5. SUPPLEMENT TO TIIE FOREGOING TABLE. 225 INTRODUCTION. ABOUT two years ago, while engaged upon the study of some interesting points in theoretical chemistry,' the compiler of the following tables had occasion to make frequent reference to the then existing lists of specific gravities. None of these, however, were complete enough for his purposes. B6ttger's work was too old, and not suitably arranged; and the tables published in the various larger treatises on chemistry were lamentably small. Accordingly he prepared a set of Specific Gravity Tables for his own private use, without view toward publication. The material proved abundant; revisions and re-revisions became necessary, and, finally, it seemed to the writer advisable to complete.and publish the tables. And in the final revision the boiling and melting points, and the references to original papers were added. Of course, having grown out of the individual needs of the compiler, the character of the tables has been shaped by the nature of the work upon which he was at first engaged. It was necessary for him to compare the specific gravities of similar compounds of the same elements, and to arrange them in series. In consequence it will be found, on reference to those portions of the tables containing organic compounds, that no rigid theoretical arrangement could well be followed. It would be very well, doubtless, to be able to compare at a glance the properties of ethyl and all its compounds, or of benzol and all its derivatives. But such an arrangement would necessitate the comparison of hydro-carbons with oxygenated, chlorinated, nitrogenous, or organo-metallic bodies; or, in other words, the comparison 1 ~2 INTRODUCTION. of compounds built up of dissimilar elements; this, however, was not the writer's purpose. And a glance at the tables will show that the arrangement is essentially different. All the hydro-carbons are placed together, arranged, as far as possible, in regular series, with reference to their chemical relations. So also all compounds containing carbon, hydrogen, and oxygen, united together without the presence of other elements, and so on. The Table of Contents will doubtless prove a sufficient key to the arrangement. That the tables are absolutely complete, is not claimed for them, especially as their scope is limited. They contain no determinations of specific gravity for solutions, and all such must be sought for in Storer's "Dictionary of Solubilities." And they contain but few determinations of natural minerals, most of the silicates, especially, being omitted. Again, numerous old determinations of specific gravity are left out, as having been rendered utterly valueless and supplanted by more recent and more accurate observations. In short, all that is claimed for the work is, that it forms a practically complete table of the specific gravities of artificial compounds of definite constitution: all else in the table is gratuitous. There are some determinations of specific gravities of natural minerals, chiefly those of comparatively simple composition quite full sets of observations for most of the chemical elements, and a good number of determinations for the leading alloys. So with the boiling points and melting points; they have been added merely to supplement the specific gravities: but as far as the table claims thoroughness, it will be found complete. Up to June 1, 1871, little has been omitted, except in the cases mentioned above. There is one obvious objection to the method of arranging determinations of physical constants in tables. Details cannot be given. In many cases there are important questions of detail to be considered. How was a determination made? How was the material obtained? And if several isomers are grouped under one name-as for instance the several butyl alcohols, or the isomeric bodies known as cumolwhich one is meant when a specific gravity is given? All these ques INTRODUCTION. 3 tions cannot be easily answered in a table of this sort. In order to relieve this difficulty, the references to original papers have been supplied. Almost every determination in the tables is accompanied by such a reference. Some of these, indeed, are not direct references to the paper of the investigator, but to the "Jahresbericht," by means of which, however, the paper itself can be found. Some determinations, nevertheless, lack such references. They were among those which formed the first table, compiled for private use, and which I have not been able since to trace back to their sources. In conclusion, a brief statement of the extent of the work here presented may be desirable. The table, exclusive of its supplement, contains the specific gravities of 2263 substances, and over 5000 determinations in all. There are over 2000 determinations of boiling point, representing 1205 different substances; and nearly 500 of melting point, for 326 different substances. In all, the names of 2572 distinct bodies will be found in the table. The work may contain errors-especially errors of judgment in arranging the material-but the writer hopes that these are few in number. And he feels sure that all who have experienced the difficulties of preparing such work for the press, will readily pardon the mistakes which may have occurred. F. WY. C. BOSTON, April 14th, 1872. A LIST OF THE MORE IMPORTANT OF THE PAPERS USED IN COMPILING THE FOLLOWING TABLES. I. PAPERS UPON ATOMIC VOLUME AND SPECIFIC GRAVITY. 1. W. HERAPATH. —"Contributions to our knowledge of chemical bodies." Phil. Mag. 64. (i824). 321. 2. BOULLAY. —"Dissertation sur les modifications que subit le volume des corps solides dans les combinaisons chimiques." Ann. Chim. Phys. (2). 43. (I830). 266. Poggend. Annal. 19. 107. 3. KARSTEN.-" Verhiltniss chemischer Mischung zur Form." Schweig. Journ. 65. (1832). Two papers; pages 320, 394. 4. KoPP.-" Ueber das Volumenometer, ein Instrument zur Bestimmung des Volums fester oder fliissiger K6rper." Ann. Chem. Pharm. 35. 17. 5. KoPP. —"Ueber Atomvolum, Isomorphismus, und specifisches Gewicht." Ann. Chem. Pharm. 36. (I840). 1. Ann. Chim. Phys. (2). 75. 406. 6. KoPP. —"Ueber die Vorausbestimmung einiger physikalischen Eigenschaften bei mehreren Reihen organischer Verbindungen." Ann. Chem. Pharm. 41. (I842). Two papers; pages 79, 169. 7. KoPP. —"Recherches sur le volume specifique." Ann. Chim. Phys. (3). 4. (1842). 462. 8. Kopp. —"Ueber den Zusammenhang zwischen der chemischen Constitution und einigen physikalischen Eigenschaften bei fliissigen Verbindungen." Ann. Chem. Pharm. 50. (I844). 71. 9. SCHR6DER. —"Volumes moleculaires des substances organiques liquides." Ann. Chim. Phys. (3). 13. (I845). 157. 10. L6WIG. —"Ueber den Zusammenhang zwischen den Atomvolumen und Atomgewichten der fliissigen organischen Verbindungen." Poggend. Annal. 64. (1845). Two papers; pages 209, 515. 11. PLAYFAIR AND JOULE. —"On atomic volume and specific gravity." Chem. Soc. Memoirs, 2. (I845). 401. Second paper, vol. 3. (I848). 57. 4 PAPERS UPON ATOMIC VOLUME AND SPECIFIC GRAVITY. 5 12. FILHOL. —"Etudes sur le rapport qui existe entre le poids atomique, la forme cristalline, et la densite des corps." Ann. Chim. Phys. (3). 21. (1847). 415. 13. KoPP. —"Untersuchungen fiber das specifische Gewicht, die Ausdehnung durch die WVirme und den Siedpunkt einiger Fliissigkeiten." Poggend. Annal. 72. (I847). Two papers; pages 1, 223. 14. PLAYFAIR AND JOULE.-" Researches upon atomic volume and specific gravity."" Journ. Chem. Soc. 1. (I849). Two papers; pages 121, 139. 15. PIERRE. —"Memoire sur la thermometrie, et en particulier sur la comparison du thermometre a air avec les thermometres a liquides." Compt. Rend. 27. (1848). 213. Poggend. Annal. 76. 458. 16. DELFFS.-Abstract of important paper by. Ann. Chem. Pharm. 92. (I854). 277. 17. Kopp. —"Beitrdige zur St5ichiomnetrie der physikalischen Eigenschaften chemischer Verbindungen." Ann. Chem. Pharnm. 96. (I855). Three papers; pages 1, 153, 303. 18. KorP.-" Untersuchungen uiber das specifische Gewicht, die Ausdehnung durch die Wiirme, und den Siedpunkt einiger Fliissigkeiten." Ann. Chem. Pharm., 94, 257. 95, 307. 98, 367. (I855 and 1856). 19. KoPP. —"Ueber die specifischen Volume der Stickstoffhtltigen Verbindungen." Ann. Chem. Pharm. 100. (I856). 19. 20. SCHIFF. —"Ueber die specifischen Volume einiger Reihen anorganischer Verbindungen." Ann. Chem. Pharm. 107. (I858). 64. 21. SCHIFF.-"Ueber die specifischen Volume anorganischer Verbindungen." Ann. Chem. Pharm. 108. (I858). 21. 22. D'ANDREEFF.-Recherches sur le poids specifique et la dilatation par la chaleur de quelqes gaz condenses." Ann. Chim. Phys. (3). 56. (I859). 317. 23. SCHR6DER.-" Neue Beitrige zur Volumentheorie." Poggend. Annal, 106. (I859). 226. Second paper; 107. 113. 24. TSCHERMAK.-" Ueber den Zusanmmenhang zwischen der chemischen Constitution und dem relativen Volumen bei fliissigen Verbindungen." Sitzungsb. Wien Akad. 35, 18. Second paper; 37. 525. 25. SCHIFF. —"Die specifischen Volume starrer Verbindungen." Ann. Chem. Pharm. 112. (I859). 88. 26. B6DEKER.-" Die Beziehungen zwischen Dichte und Zusammensetzung bei festen und liquiden Stoffen. Ein Supplement zu den Lehrbilchern der Chemie und Mineralogie." Leipzig. (I86o). 27. TSCHERMAK. —"Die Dichte iml Verhdltnisse zur Form und chemischen Beschaffenheit der Krystalle." Sitzullgsb. Wien Akad. 45. (2). (I862). 603. 6 PAPERS UPON EXPANSION. 28. SAFARIK.-" Beitrige zur Kenntniss der specifischen Volumen fester Verbindungen." Journ. fuir Prakt. Chem. 90. (I863). 12. 29. H. L. BUFF. —"Ueber eine Beziehung des Gesetzes der multip]en Proportionen zu den specifischen Volumen." Ann. Chem. Pharm. 4th Supp. (I865-6). 129. 30. LOUGUININE. —"Itude des densites et dilatations de la benzine et de ses homologues."-Ann. Chim. Phys. (4). 11. (I867). 453. 31. KREMERS. —"Ueber das relative Volum der Verbindungen erster Ordnung." Poggend. Annal. 130. (I867). 77. 32. HAAGEN. —"Bestimmung der Brechungsexponenten und specifischen Gewichte einiger flfissigen Haloidverbindungen." Poggend. Annal. 131. (1867). 117. 33. JUNGFLEISCH."-"Sur quelques relations entre les points de fusion, les points d'ebullition, les densites, et les volumes specifiques." Compt. Rend. 64. (1867). 911. II. PAPERS UPON EXPANSION. See also several of the papers already cited. 34. DANIELL.-" On a new register-pyrometer, for measuring the expansion of solids, and determining the higher degrees of temperature upon the common thermometric scale." Phil. Trans. (I830). 237. 35. DANIELL.-" Further experiments with a new register-pyrometer for measuring the expansion of solids." Phil. Trans. (I831). 443. 36. MUNcKE.-"Ueber die Ausdehnung der tropfbaren Fliissigkeiten durch Wirme." Mem. Acad. St. Petersburg. Savans Etrang. I. (I831). 249. 37. STAMPFER.-" Versuche zur Bestimmung des absoluten Gewichts des Wassers, der Temperatur seiner gr6ssten Dichtigkeit und der Ausdehnung derselben." Poggend. Annal. 21. (I83I). 75. 38. MUNCKE. —"Sur la dilatation de l'alcool absolu et du carbure de soufre par la chaleur." Ann. Chim. Phys. (2). 64. (I837). 5. 39. DESPRETZ.-" Recherches sur le Maximum de Densite de l'Eau pure, et des dissolutions aqueuses." Ann. Chim. Phys. (2). 70. (z839). 5. 40. DESPRETZ. —"Observations sur la dilatation du soufre." —Compt. Rend. 7. (1838). 589. 41. SALM-HORSTMAR. —"Ueber die Ausdehnung des fluissigen Wassers unter dem Gefrierpunkt."-Poggend. Annal. 62. (I844). 283. 42. BRUNNER.-" lxperiences sur la densite de la glace a differentes temperatures." Ann. Chim. Phys. (3). 14. (I845). 369. 43. PIERRE. —"Recherches sur la dilatation des liquides." Ann. Chim. Phys. (3). 15. (1845). 325. 44. Continuation of No. 43. Ann. Chim. Phys. (3). 19. (I847). 193. PAPERS UPON EXPANSION. 7 45. PIERRE.-" Recherches sur les proprietes physiques des liquides, et en particulier sur leur dilatation." Ann. Chim. Phys. (3). 20. (I847). 5. 46. PIERRE. —" Recherches sur la dilatation et sur quelques autres proprietes physiques de l'acide sulfureux anhydre et du sulfite d'oxyde d'ethyle." Ann. Chim. Phys. (3). 21. (I847). 336. 47. MILITZER.-" Ueber die Ausdehnung des Quecksilbers durch die Wairme." Poggend. Annal. 80. (I85o). 55. 48. PIERRE.-"Recherches sur les proprietes physiques des liquides, et en particulier sur leur dilatation." Ann. Chim. Phys. (3). 31. (I851). 118. 49. PIERRE. —"Recherches sur la dilatation." Ann. Chim. Phys. (3). 33. (i851). 199. 50.-KoPP. —" Ueber die Ausdehnung einiger fester Korper durch die Warme." Ann. Chem. Pharm. 81. (I852). 1. Poggend. Annal. 86. 156. 51. HAGEN.-" Ueber die Ausdehnung des distillirten Wassers unter verschiedenen Warmegraden." Abhandl. Akad. d. Wiss. zu Berlin. (I855). 52. PFAFF.-" Untersuchungen fiber die Ausdehnung der Krystalle durch die Warme." Poggend. Annal. 104. (I858). 171. Second paper, 107. 148. 53. DRION.-" Note sur la dilatabilite des liquides chauff6s a des temperatures superieures a celle de leur ebullition." Compt. Rend. 46. (I858). 1235. Poggend. Annal. 105. 158. 54. SORBY.-" On the expansion of water and saline solutions at high temperatures." Phil. Mag. (4). 18. (I859). 81. 55. HAHN.-" On the expansion of crystalline bodies by heat." Phil. Mag. (4). 18. (I859). 155. 56. MENDELEJEFF.-" Notiz fiber die Ausdehnung homologer Fliissigkeiten." Ann. Chem. Pharm. 114. (I86o). 165. 57. MENDELEJEFF. —"Ueber die Ausdehnung der Flfissigkeiten beim Erwdirmen fiber ihren Siedepunkt." Ann. Chem. Pharm. 119. (I861). 1. 58. CALVERT, JOHNSON, and LOWE.-" On the expansion of metals and alloys." Chem. News. 3. (I86I). Pages 315, 357, 371. 59. DuvENoY.-"Ueber die Ausdehnung des Wassers beim Gefrieren." Poggend. Annal. 117. (I862). 454. 60. FIZEAU.-" Recherches sur la dilatation et la double refraction du cristal de roche echauffM." Ann. Chim. Phys. (4). 2. (I864). 143. 61. FIZEAU. —"Sur la dilatation du diamant et du protoxyde du cuivre cristallise sous l'influence de la chaleur." Compt. Rend. 60. (I865). 1161, 62. WEIDNER.-" Die Ausdehnung des Wassers bei Temperaturen unter 4~ R." Poggend. Annal. 129. (I866). 300. 63. FIZEAU.- "Memoire sur la dilatation des corps solides par la chaleur." Ann. Chim. Phys. (4). 8. (I866). 335. 64. MATTHIESSEN.-" On the expansion by heat of water and mercury." Phill. Trans. (I866). 231. 8 PAPERS UPON BOILING AND MELTING. 65. MATTHIESSEN. —"On the expansion by heat of metals and alloys." Phil. Trans. (I866). 861. Poggend. Annal. 130. 50. 66. HIRN.-" Memoire sur la thermodynamique. Recherches experimentales sur la dilatation et sur la capacit6 calorifique a des hautes temlpe'ratures de quelques liquides tres volatiles." Ann. Chim. Phys. (4). 10. (1867). 32. 67. ROSSETTI.-" Sur le maximum de densite et la dilatation de l'eau distillee." Ann. Chim. Phys. (4). 10. (I867). 461. Second paper, v. 17. (I869). 370. 68. FIZEAU.-" Sur la propriete que possede l'iodure d'argent de se contracter par la chaleur et de se dilater par le froid." Compt. Rend. 64. (i867). 314. Another paper, same vol., p. 771. 69. FIzEA. —" Tableau des dilatations par la chaleur de divers corps simples metalliques ou non metalliques, et de quelques compos6s hydrogen6s du carbone." Compt. Rend. 68. (I869). 1125. 70. PIERRE and PucHoT. —" Ueber einige Gthrungs-Alkohole und Derivate derselben." Ann. Chem. Pharm. 153. (I870). 259. 71. PIERRE and PUCHOT.-" Ueber den Propionyl — den Butyryl - und den Valerylaldehyde." Ann. Chem. Pharm. 155. (I870). 362. III. PAPERS UPON BOILING AND MELTING. 72. A. F. andL. F. SviANBErG.-"Versuche fiber die Erstarrungspunkte terndrer Legirungen aus Zinn, Blei, und Zink." Poggend. Alinal. 26. (I832). 280. 73. SCHRiDER. —"Die Siedhitze der chemischen Verbindungen, das wesentlichste Kennzeichen zur Ermittlung ihrer Componenten.?" Poggend. Annal. 62. (I844.) Two papers; pages 184, 337. 74. SCHR6DER.-" Ueber die Siedhitze der chemischen Verbindungen." Poggend. Annal. 64. (I845). 96. 75. PEnSON.-" Recherches sur la chaleur latente." "Note sur la loi qui regle la chaleur latente de vaporisation." Compt. Rend. 23. (I846). Two papers; pages 162, 524. 76. REGNAULT.-"NOte sur la chaleur specifique de potassium et sur les temperatures d'ebullition de l'acide carbonique et du protoxyde d'azote sous la pression ordinaire de l'atmosphere." Compt. Rend. 28. (I849). 325. 77. ScHR6DER.-"Ueber den Einfluss der Elemente auf die Siedhitze." Poggend. Annal. 79. (I85o). 34. 78. GROSHANS. —"Bemerkungen fiber die entsprechenden Temperaturen, die Sied- und Gefrierpunkt der K6rper." Poggend. Annal. 78. (I 49). 112. 79. Kopp.-"Ueber Siedpunkts-Regelmassigkeiten, und H. Schr6der's neueste Siedepunktstheorie." Poggend. Annal. 81. (I85o). 374. PAPERS UPON BOILING AND MELTING. 9 80. BouIs.- "Observations sur la fusion et la solidification." Ann. Chim. Phys. (3). 44. (I855). 152. 81. KoPP.-" Ueber die Siedepunkte entsprechenden Brom- und Chlorverbindungen, und die Formeln der Siliciunl- und Titanverbindungen." Ann. Chem. Pharm. 98. (I856). 265. 82. KoPP.-" Sur quelques regularites dans les points d'ebullition des combinaisons organiques." Ann. Chin. Phys. (3). 49. (r857). 338. 83. SCHAFFGOTSCH.-" Ueber zwei ausgezeichnete Beispiele der Schmelzpunktserniedrigung." Poggend. Annal. 102. (I857). 293. 84. Kopp.-" On tlhe relation between boiling point and composition in organic compounds." Phil. Trans. (I86o). 2.57. 85. KoPP. —"Ueber die Siedepunkte der Kohlenwasserstoffe C, H2n-6." Ann. Chem. Pharm. 5th supp. (I867). 315. 86. TOLLENS. —"Sur les points d'ebullition des composCs allyliques." Bull. Soc. Chim. 11. (i869). 398. 2 EXPLANATORY NOTES. EACH of the following tables, with two exceptions, is divided into five columns. The first contains the Name of the Substance, the second its Formula, the third its Specific Gravity, the fourth its Boiling Point, and the fifth its Melting Point. From the Table of Elementary Substances, however, the column for formula is omitted; and in the Table of Alloys, no boiling points are given. The authorities are added as foot-notes to each page. Some abbreviations are necessarily used. In the first column, the letter "s." placed after the name of any substance, shows that that substance is a solid, or was examined in the solid state. The letter "1." similarly used, stands for liquid. Thus, "Acetic acid. s.," stands for solid acetic acid; and " Chlorine. 1.," for liquefied chlorine. Among organic substances, the abbreviations "iso," and the Greek letters alpha or beta are sometimes appended to the name of a substance. These are simply to distinguish isomers from each other; as, for instance, isopropyl from propyl compounds, and alpha- from beta-xylidine. In the Specific Gravity column the letters "s." and "1." are also employed, and indicate that the determinations to which they are appended are for the substances in question in the solid or liquid state. The letter "a." attached to a determination shows the latter to be merely approximate. Expressions like "m. of 3," "Im. of 5," &c., affixed to a number, show it to be a mean of 3, mean of 5, &c., determinations. And the abbreviations " Precip.," "Artif.," " Cryst.," "Ign.," &c., stand simply for the words precipitated, artificial, crystallized, and ignited, and express of course the character of the material employed in making a determination. In the column devoted to Boiling Points, the letter "a." is again used to express approximation. Thus, "160~ a." stands for about 160.~ When barometric measurements are given, "m. in." of course stands for millimetres. The plus and minus signs are employed to show that a determination is a 10 EXPLANATORY NOTES. 11 little above or a little below accuracy. 100~+, would mean a little more than 1000, and 100 —, a little less. "d.," or "p. d.," affixed to a boiling point determination, indicates that the substance in question is either decomposed, or partly decomposed in boiling. In the column of Melting Points, the letters "a.,.." d.," and "p. d.," and the plus and minus signs, are used precisely as with the Boiling Points. The letter "s.," however, shows that the temperature attached is that at which the body named solidifies. "rs." stands for resolidification. Thus, "82.~ rs. 78~" would show that a body melted at 82~, and resolidified at 78.0 In the lists of Authorities a variety of abbreviations are used, to point out the whereabouts of the original paper, or the source from which a determination was obtained. References to "Dana's Mineralogy," "Watts' Dictionary," "Strecker's Lehrbuch," "Kekule's Lehrbuch," and "Weltzien's Systematische Zusammenstellung der Organischen Verbindungen," will of course be readily recognized. But most of the abbreviations require detailed explanation. A single number appended to the name of an authority, refers to the list of papers accompanying the tables. Thus, "Kopp. 18," would refer to Kopp's paper numbered 18 in the list; or "Filhol. 12," to Filhol's paper numbered 12. Two numbers affixed to a name, refer to the "Jahresbericht," volume and page. Thus, "Kenngott. 6. 853," refers to vol. 6, p. 853 of the above-named work; or "Luca. 13. 98," to vol. 13, p. 98& The following abbreviations refer to various periodicals,-the series, (when necessary), volume, and page, being always given. If the number for the series be omitted, the first series is understood to be the one referred to. The page is sometimes that at which a paper begins, and sometimes merely that upon which a given determination is to be found. Ann. Phil. "Annals of Philosophy." A. C. P. "Annalen der Chemie und Pharmacie." A. C. Phys. "Annales de Chimie et de Physique." B. S. C. "Bulletin de la Societe Chimique." Chem. N., or Chem. News. "Chemical News." Chem. Gaz. "Chemical Gazette." C. R. "Comptes Rendus." C. S. J., or J. C. S. "Journal of the Chemical Society." C. S. Mem. "Chemical Society's HMemioirs." 12 EXPLANATORY NOTES. D. P. J., Ding. J., or Dingler's J. "Dingler's Polytechnisches Journal." Erd. J. "Erdmann's Journal." Gilb. Ann. "Gilbert's Annalen." J. F. P. "Journal ffir Praktische Chemie." Mem. Amer. Acad. "Memoirs of the American Academy." Nich. J., or Nich. Journ. "Nicholson's Journal." P. A. "Poggendorf's Annalen." "Erganz. bd." refers to the "Erganzungs Band." P. MI. "Philosophical Mlagazine." P. T., or Phil. Trans. "Philosophical Transactions." Q. J. S. "Quarterly Journal of Science." Schw. J., or Schweig. J. "Schweigger's Journal." S. J., or Sill. J. "Silliman's American Journal." Wien Ak. "Sitzungsberichte der Akademie zu Wien." Zeit. An. Chem., or Zeit. Anal. Chem. "Zeitschrift fir Analytische Chemie." A TAB LE OF SPECIFIC GRAVITIE S. BOILING POINTS AND MELTING POINTS, FOR SOLIDS AND LIQUIDS. I. ELEMENTARY SUBSTANCES. Name. Specific Gravity. Boiling Point. Melting Point. Hydrogen. Fluorine. Chlorine. 1. 1.33, 15~.5. 2,, -33.o6.76o.m.m. 3 Bromine. 2.966. 47.0 4 (( 2.98-2.99, I5.0 45.0 (5 1 3. I87 I8, o. 63.-76om.m. 6,, 58.~ (( 7 (C S.-22.~ 8 Iodine. 4.948-. I75~-I80.0 I07. 9 4(( F4.9173, 40. 03.. 4.886, 60.~ 11 S s. 4.-857, 79.~06. 12 (( | 4.84I, 89.~8. 13 (( 4.825, 107.0 14 (( 4.004, I07.0 15 o| 3-988, I I I.~7. 16 ( 3-944, 124.03. 172 2 1. 1 3.918, 133-05. _18, 3.866, I5I.~ 19 1( 3.796, 170.~ 20 Lithium. 0o.578,-. 589. I80.0 21 Sodium. o.9348. 22 ( o0.97223, 15.~ 23 (( S. 97.%6. 24 o0.985. 25 (( 95.c6. AUTHORITIES.'Watts' Dictionary. 9 Billet. 8.46. 18 Billet. 8.46. 2 Regnault. 16.70. [337. 10 Billet. 8.46. 19 Billet. 8.46. 3Balard. A. C. Phys. (2).32. l' Billet. 8.46. 20 Bunsen. 8.324. 4 L6wig. Watts' Dictionary. 12 Billet. 8.46. 21 Davy. P. T. 1808.21. 5Pierre. 45. 13 Billet. 8.46. 22 Gay-Lussac and Th6nard. 6Andrews. P. A. 75.335. 14 Billet. 8.46. Watts' Dictionary. 7 Watts' Dictionary. 15 Billet. 8.46. 23 Regnault. 9.43. 8Gay-Lussac. A. C. Phys. 16 Billet. 8.46. 24 Schr6der. 12.12. 1.91.5. 17 Billet. 8.46. 25 Bunsen. 16.178. 13 14 SPECIFIC GRAVITY TABLES. Name. Specific Gravity. Boiling Point. Point Point. IPotassium. 0.865, 15.~ 2 0.870. 3 (( I~Melted. 0.8427. 4 s(( s 55-04~ 62.05. 6 Rubidium. I.52. 38.05. 7 Caesiusm. I Silver. I034.~ 9 0 I 000.0 10 I0.472. 11 10.362, I0.0 12 U 999.0 13 1( I024.0 14 (1 I0.43-10.47. 15 I10.575. 16 10.4282. 7 10.434. 8 ( 10.522. 19 (( I537 (20 10.482. 21 I0.505, after fusion. Io.5665, pressed. 23 zzI 0.5532, precipitated 24,, I0.6I9I,5 powder. 25 I0.5287, m. of I3. 26 I.5237, m. of 4. 2 I0.5283, m. of 8. 28 1( I0.468, I3.0 29 I.77, I5.05. Native. 30,Melted. 9I3 I 31, 9.28I. 32 Thallium. I.862. 290.0 33 (I I1.808, wire. 34 ( II.853,5 cast. AUTHORITIES. 1 Gay-Lussac and Th16nard. 12Prinseps. P. T. 1828.94. 23 G. Rose. P. A. 73.1. Watts' Dictionary. 13 Daniell. P. T. 1830.237. 24 G. Rose. P. A. 73.1. 2Senlentini. 14 Lengsdorf. 25G. Rose. P. A. 73.1. 3 Playfair and Joule. 11. 15 Christomanos. 26 G. Rose. P. A. 73.1. 4Regnault. 9.43. 16Karsten. 3. 27G. Rose. P.A. 73.1. 5 Bunsen. 16.178. 17 Breithaupt. J. F. P. 11. 28 Holzmann. 13.112. 6 Bunsen. 16.185. 151. 29 Forbes. P. M. (4). 30.139. 8 Guyton-Morveau. Watts' 18 Playfair andJoule. 11. 30 Plafair and Joule. 11. 1 Dictionary. 19 Playfair and Joule. 11. 31 Playfair and Joule. 11. 9 Pouillet. WVatts' Diet. 20 Karmarsch. J. F. P. 43.193. 32 Lamy. 15.180. 10 Brisson. See 11. 21 G. Rose. P. A. 73.1. 33 De la Rive. 16.248. 11 Biddle. P. 31. 30.152. 22 G. Rose. P. A. 73.1. 34 De la Rive. 16.248. SPECIFIC GRAVITY TABLES. 15 Melting Name. Specific Gravity. Boiling Point. Point 1Thallium. I I777.*. 2 I 1.900.1 3 (q I i.8I, cast. 4 (( I.88, pressed. (5 11.91, wire. 6 Oxygen. 7Sulphur. 1.9907, roll. i.868, ( (( 2.086, flowers. 10 1.898, crystallized. 11 1 I.927, from solution. 12 1.989, crystallized. 13 1.9777-2.oooo 0000, roll. 14 (( 2.072, prismatic. 3 2.086, native. 16 (( 2.027, soft. 17,, 2.05001, native. 18 (( I.9889, from fusion.) 19 (( 440.0 20 (( I.982, prismatic. ) 21 2.066, native. I 111.05. 22 8 22 2.058, from solution. j 23 1. I957, soft. 24 ((I I15' 2, I.919, soft. 26 1((,928, (( 27 (( I.958, prismatic. 28 (( 2.070, native. 29 (( 2.063, from solution. 30 2.010, crystallized. ) 81 (( 1.913, flowers. 32 I.92 I, waxy. AUTHORITIES, I Werther. 17.247.'1 Dumas & Roget. 24 Persol. 1.73. [365. 2 Werthler. 17. 247.- 16 Osann. 25 C. J. St. Claire Deville. 1. 3 Crookes. J. C. S. 1864.11. ) 17 Karsten. 3. 26 C. J. St. Claire Deville. 1. 4 Crookes. J. C. S. 1864.112. 18 Karsten. 3. J 365. 5 Crookes. J. C. S. 1864.112. J 19 Watts' Dictionary. Duinas. 27 C. J. St. Claire Deville. 1. 7 Brisson.. 20 Marchand and Scheerer. 1 365. 8 Bhckmann. J. F. P. 24.129. 28 C. J. St. Claire Deville. 1. 9 Gehler..2 MAarchand and Scheerer. 365. 10 Fontenelle. g, ~ J. F. P. 24.129. 29 C. J. St. Claire Deville. 1. 11 Bischof. 22 Marclhand and Scheerer. I 365. 12 Breithaupt.: J. F. P. 24.129. 30 Playfair and Joule. 11. 13 Thomnson. 23 Marchand and Sclleerer. 31 Playfair and Joule. 11. 14 Mohs. J J. F. P. 24.129. 132 Playfair and Joule. 11.. 16 SPECIFIC GRAVITY TABLES. Name. Specific Gravity. Boiling Point. Melting Point. Sulphur. Melted. I.8oI. Extremes of five 2 1 u i.81 5.5 determinations. I I4.~5. Octac3 hedral. I20.~ Pris~4 {. matic. "5 ((490.~760 m. m. 6 (C 447.0'Selenium. 4.3-4.32. 8 ( 4.3I9 (( 1 4.808, I5.~ 2I7.~ 10 (( 4.805. ) crystallized' 12 ((/14.796. J from fusion. 12, j 4.'276. 20o. 13 4.286. Amorphous. 14 <(4.24 5. Red. 15 4.275. Precipitated. 16 ( 4. 250. Ditto, after 17 A.-V7 J heatingctoso.0~ 4.5209~ 18 4.460.) U19 ( 44.509. Crystallized. 4.700. ( 21 4.760. I 5.~crvstallized 22" ( 4.788. from solution. 23 4.80. 24 4.8I. } Black. 25, 4.26. Red. 26 (( 4.28. Precipitated. 27 Tellurium. 6. I 5. 28 (( j 6.138. 29 (( 6.2445, m. of 5 30 6.343. 31 6.I80. 32 8 a. 500.~ AUTHORITIES. Playfair and Joule. 11. 12Schaffotsch. 6.329. 23 Rathke. J. F. P. 108.235. 2 Playfair wand Jotule. 11.S 1 Schaff-otsch. 6.329. 24 Rathke. J. F. P. 108.235.' Brodie. J. F. P. 62.336.' 4 Sclaffgotsch. 6.329. 25 Rathke. J. F. P. 108.235. 4 Brodie. J. F. P. 62.336. S15 Schaffgotsch. 6.329. 26 Ratlke. J. F. P. 108.235. 5Reginault. 16.70.'6Schaffgotsch. 6.329. 27 Klaproth. A. C. Phys. 25. 6 Hittorf. 18.130. 17 Schaffgotsch. 6.329. 273. 7 Berzelius. 18 Mitscherlich. 8.314. 28 Magnus. 8 Boullay. 19 Maitscherlich. 8.314. 29 Berzelius. P. A. 28.392. 9 Hittorf. 4.319. 20 Mitscherlich. 8.314. 30 Reichenstein.,0 Schaffgotsch. 6329. 2t' Mitscherlich. 8.314. 31 Lowe. J. F. P. 60.163. "Scnhaffgotsch. 6.329. 22 Mitscherlich. 8.314. 32 Watts' Dictionary. SPECIFIC GRA VITY TABLES. 17 Melting Name. Specific Gravity. Boiling Point. Point.' Calcium. i.566. 2 (( I.584. 3 1. I.584. 4 ( 1.55. 5 I1.6-I.8. 6 Strontium. 2.504. (7, 2.580. 8 ( 2.4. 9 Barium. a. 4.00. 1o Lead. II_44S. 11 11.352. 2 ( 1 1.207. 13 ( I 1.388. 14 I 1.3303. 334. 1( I I.346, I 5.~50 S.322.3 6.((.I I.352. 17 322.0 28 (1.3888. 19 II.070. 20 11.275. 21 I I.280. 22 I 1 II.298. 23 332.0 24, 326.~ 25 (( 11.370,0.~. 26 (( I1.3525, I8.~ 27 ( II1.395, 4. 28 I 11.254-11.363. 29 (( II.376, I4.0 30 (( I0.450. 31 Melted. I10.5I3. 32 (( Io.563. AUTHORITIES. 1 Matthiessen. 8 324. 12 ckmann. ee22 Playfair and Joule. 11. 2Matthiessen. 8.324. 13Morveau. See 11. 23 Person. 1.72. 3 Matthiessen. 8.324. 14 Kupffer A. C. Phys. (2). 24 Rudberg. 1.71. 4Lies-Bodart and Jobin. 11. 40.292. 25 Reich. 126. 25 Crichton. P. M. 16.48. 26 Reich. J 5 Caron. 13.119. 16 Herapath. 1. 27 Streng. 61\Iatthiessen. 8.324. 1 7 Daniell. 34. 28 C. St. Claire Deville. 8.15. 7Matthiessen. 8.324. J s Karsten. 3. 9 Holzmann. 13.112. 8Franz. J. F. P. 107.253. 19 Playfair and Joule. 11. 30 Plavfair and Joule. 11 Clarke. G-ilb. Ann. 55.28. 20Playfair and Joule. 11. 31 Playfair and Joule. 11. 11. 21 Playfair and Joule. 11. 0o Muschenbroek. 21 Playfair and Joule. 11. 13 Playfair and Joule, 11. 11 Brisson. fSee 11. 18 SPECIFIC GRA VITY TABLES. Name:. Specific Gravity. Boiling Point. Melting Point. c 7.I47. 20.04. 3 o (7.277. In laminae. 4 ( 7-362, I5.o 5,, 7.42 1, I6.~8. 176.~ 6 Chromium. 7.3(( 6.8I, 25.0 Crystallized. 8 6.20. Reduced by K Cy. 9 Manganese. 6.86-7. I. 10 ( 8.03. 11 8.oI03. 12 0 7.I38-7.206. 13 Iron. 7.4839, bar. 14 (( 7.8707. (15C 7.865. 7.788. T7 (C 7.790, wrought. 18 7.I30. Reduced by C. 19 8.1393, I { 05 Electro8.393, 5.5. lytic. 20 ( 7.50. Reduced by 21 7.84. J zinc vapor. 22, 22(( C7.6305. Wire in sev23 7.6000. eral differ((24 7.7169. ent condi235 7.7312. J tions. 26 7.7433. Hammered. 27 T ( 7.998. Io.~ 2 8.00oo7. J Reduced by H. 29,, 6.03. Reduced by H. 30 cc Meteoric. 7.3I8. From Guilford. 31 <(z(C 7.82. 32 ( (s2 <( z 7.814. AUTHORITIES. Reich and Richter. 17.241. 12 Brunner. 10.202. 22 FBaudrimont. J. F. P. 7.268. 2 Reich and Richter. 17.241. 13 Br6oling. s et-23 Baudrimont. J. F. P. 7.268. 3 Reich and Richter. 17.241. 14 Berzelius. 24 i tJ. 268 4 Winkler. 18.233. 15 { Berzelius. allurgy. 2 Baudrimont. J. F. P. 7.268. 5 Winkler. 20.262. 16 Brisson. See 11. 26 Baudrimoont. J. F. P. 7.268. 6 Bunsen. 17 Karsten. 3. 27 Schiff S 7 W6hler. 12.169. 18 Playfair and Joule. 11. 2 Schiff. J See 23. 8 Loughlin. 21.220. 19 Smith. Percy's Metal- 29 Stahlschmidt. 18.255. 9 Bergmann. lurgy. 30 Dana's Mineralogy. lO Bachmann. ISee1 20 I Poumarede. 2.281. 31 Rumler. See 23. "John. P. M. 2.176. 21 ) Pounlarede. 2.281. 32 Patera. See 23. SPECIFIC GRA VITY TABLES. 19 Nam.:Melting Name. Specific Gravity. Boiling Point. Melting Point. 1Nickel. 7.807. 2 (( 8.279. 3 (( 8.380. 8.402. 5 (, 84776,, 8.637. 7 O, 7.861. } Reduced by 8,, 7.803. hydrogen. 9,, 8.88, 4.0 Wire. 10 o 8.975. Reduced by (1, 9.26i. hydrogen. 12,, 8.9oo. 23 Cobalt. 8.7Io. 14,, 8.485. 15 8.500. 16 ( 8.5131'17 ((8.538. 18 8.558. 19 7.7I8. } Reduced by 20 (( 8.26o. hydrogen. 21 (( 8.957. Red. by H.m.of 5. 22 Uranium. 18.40. 23 (( I8.33. 24 Copper. I00~ -I200. (25 C 1207.o 26 (( 8.895. 27 ( 8.878, rolled. 28 8.788, cast. 29 (( 8.83, cast. 30 8.9463, drawn. 31 ( 8.9587, hammered. 32,, 8.78. 33,, 8.9oo. AUTHORITIES. 1 Brisson. 13 Lampadius. Erd. J. (1). 5. 2 Pouillet. Watts' Dictionary 2 Richter. 390. 25 Guyton-Morveau. WVatts' 3 Tupputi. 1 Brunner. Dictionary. 4 Tourte. See 11. 15 Mitscherlich. 26 Hatchett. See 11. 5 Baumgartner. 16 Berzelius. See 11. 27 Brisson. 6 Brunner. 17 Hi/iy. I28 Brisson. See the paper 7 Playfair and Joule. 11. 18 T. H. Henry. 2 Berzelius. by Marchand & 8 Plavfair and Joule. 11. 19. Playfair and Joule. 11. 301 Berzelius. eerer. 9 Arndtsen. See 23. 20 [ Playfair and Joule. 11. Berzelius. J. F. P. 27.193. o0 I Rammelsberg. 2.282. 21 Ranlnmelsberg. 2.282. 32 Kupffer. A. C. Phys.'2). i1 Ranmmelsberg. 2.282. 22 Peligot. 9.380. 25.356. 12 Schlr~ider. 23. 23 Peligot. A. C. P. 149.128. 33 Herapc th. 1. 20 SPECIFIC GRA VITY TABLES. Name. Specific Gravity. Beiling Point. Meltin' Copper. 109I.~ 2 (( 1 8.667. 3 (( / 8.721. 4 ((8.6225. ( C 8.16225. Wire, in sev6 8'73902. eral different 1 8.8787. conditions. 8 {l8.8893, hammered. 9,, | 8.940, crystallized. o10 8.92I, cast. 11 u I 8.939. 12 o8.949.' Various sorts 13 o8.930. | of wire. 14 8.93o. 15 8.952, sheet. 16 o4 8.931, pressed. (7 zt 8.9I4, electrolytic. 18 o [8.428.) 19 8.483. Finely divided. 20 o I 8.360.J ~~21 o ~18.884.1 22 o 8.941. iElectrolytic. 22.941 23 (( 8.934- j 24 8.367. } 4.0 Finely 25 ( 8.416I3. divided. 26 8.902, 12.0 27 (1 8.838, native. 28 (1 8.952-8.958. 29 ( 8.9I6. Electrolytic, 30,, 8.958. f cast. 31 (( 8.853. L Electrolytic, 32 F, L 8.733. j wire. 33 Ruthenium. I I.o- I.4. AUTHORITIES. 1 Daniell. 34. 12 AMareliand and Scheerer. 20 Playfair and Joulle. 11. 2 Mallet. Ding. J. 85.378. J. F. P. 27.193. 21 Playfair and Joule. 11. 3 Karstenl. 3.'13 MAarchand and Scheerer. 221 Plavfair ald Joule. 11. 4 t Baudrirnont. J. F. P. 7.287. J. F. P. 27.193. 23 Plavfair and Joule. 11. 5 Baudrimlont. J. F. P. 7.287. l4 Marchand and Scheerer. 21 Playfair and Joule. 14. 6 Baudrimont. J. F. P. 7.287. J. F. P. 27.193. 25 Plavfair and Joule. 14. Baudriniont. J. F. P. 7.287. 15 Alarchalnd and Sclheerer. 26 Schiff. S Baudrimont. J. F. P. 7.287. J. F. P. 27.193. 27 Whitney. 12.769. 9 rAarchand and Scheerer. 16 Marchand and Scheerer. 28 Schrdder. 23. J. F. P. 27.193. J. F. P. 27.193.. 29v Dick. P. I. (4). 11.409. 10~Marchand and Scheerer. i7 Marchald and Scheerer. 30 Dick. P. AM. (4). 11.409. J. F. P. 27.193. J. F. P. 2.193. Dick. P. AM. (4). 11.409. I Marchand and Scheerer. 1s Plavfair and Joule. 11. 2(Dick. P. AM. (4 11.409. L J. F. P. 27.193. 19 Playfair and Joule. 11. 33 DevillealdDebray. 12.234. SPECIFIC GRAVITY TABLES. 21 Melting Name. Specific Gravity. Boiling Point. Meltn Point. 1 Rhodium. I I.O. 2 (( 1 1.2. I I.0. 4 ( 12.1. a Palladium. I 1.3-1 I.8. 6 I1 12.148.,7, 11.852. 8 I12.0. 9 c I11.04I, I8.0 10 10.923. 11 I I.628. 12 11.30. 13 I i.80, hammered. J 14 I 1.752. 15 I 11.4, 22.05. 16 Platinum. 20.85. 17 2(( 0.98. 18, 2 I.o6. 0 19 0 19.5, cast. 20 u 20.3, hammered. 21 21.0, wire. 22 2I.7, wire. 23 (( 21.06 1. 24 t 21.45. 25 e~ 21.47-21.53. 26 1( I7.7, cast. 27 ( 2 1.3. 28 (( 20.9, hammered. 29 1 21.47, spongy. 130 {z2 1. 1 6, wire. 31 21.4, wire. 32 k (32 21.53. wire. 21.25, hammered. AUTHORITIES. 1 Wollaston. 12 (Cock. C. S. Mem. 1.161. 23 Sickingen. 2Cloud. Schw. J. 43.316. 13 Cock. C. S. Mer. 1.1G1. 24Berzelius. 3 Hare. Sill. J. (1). 2.365. 14 Breithlaupt. J. F. P. 11.151. 25 Berthier. 4 Deville and Debray. 12.240. 15 Deville and Debray. 12.237. 2 Prechtl. 5 Wollaston.16 Borda. 27Faraday. 6Lowry. Watts' Dic- 17 Bor(a. See paper 28 E. D. Clarke. 1 tionary. 7 Lampadius. 18 ( Bo(rda. by Mar- I 29 Thomson. 8 Vauquelin. See 23. 19 ( Brisson. chand. J. 1 30 Wollaston. P. A. 16.15R, 9Cloud. Schw. J. 1.362. 20 Brisson. F. P. 33. 31T Wollaston. P. A, 16.15$ 1o Breithaupt 21 Brisson.21 32 i Tollaston. P. A. 16.15S 1 Benneke and Reinecker. 22 Klaproth. J 33 Wollaston. P. A. 16.153 22 SPECIFIC GRA VITY TABLES. Melting Name. Specific Gravity. Boiling Point. Meltin Point.'Platinum. 17.572. 2 15.780. Spongy. 3 C I6.3I9- C4 I I17.89. Platinum black. (C5 (21.2668.} 0.0 6 (C 21.3092.) 7 (2I-3I8 212 I.I6. Hammered. 21.23. 10 I6.634, spongy. 11 (t 1 20.9815.' 12 (( 120.7732. Black. 13 1 22.8926. Precipitated. 14 CC 122.0345. 15 26. I41I8, 15.07. (?)Black. 16 ((I7.766, black. 17:2I'I69': Spongy. 18 (.21.243.) 2 pongy 19 C, 21.15. 20 ( 21.15. 21 Iridium. I8.68, porous globule. 22 2I.78. 23 ( 21.83. 24 (( I8.6088, black. 25 2(1.15. 26 Osmium. 21.40. 27 Molybdenum. 8.490. 8.6I5. 8.636. 28 / 8.60. 29 (( 8.56, reduced by K Cy. 30 Tungsten. 17.6. 31 (17.22. 32 (17.4. 33 (( C I9.261, I2.0 t AUTHORITIES. 1 (Liebig. P. A. 17.101. 13 Rose. P. A. 75.403. 24 G. Rose. P. A. 75.403. 2 j Liebig. P. A. 17.101. 14 Rose. P. A. 75.403. 25 Deville and Debray. 12.242. 3 Liebig. P. A. 17.101. 15 Rose. P. A. 75.403. 26 Deville and Debrav. 12.232. 4 Scholz. See 11. 16 { Playfair and Joule. 11. 27 Bucholz. Nich. J. 20.121. 5 Marchand. J. F. P. 33.385. 17 Playfair and Joule. 11. 28 Debray. 11.157. 6 Marchand. J. F. P. 33.385. 18 Playfair and Joule. 11. 29 Loughlin. 21.220. 7 Hare. Sill. J. (2). 2.365.'9 Devilleand Caron. 10.259. 30 D'Elhuyart. See 11. 8 Hare. Sill. J. (2). 2.365. 20 Deville and Debrayv 12.240. 31 Allan and Aiken. See 11. 9 Hare. Sill. J. (2). 2.365. 21 Children. Watts' Dict. 32 Bucholz. Selhw. J. 3.1. 10 Rose. P. A. 75.403. 22 f Eckfelt & Boy6, for Hare. 33 Roscoe. Chem. News, Rose. P. A. 75.403. 23 (Sill. J. (2). 2.365. 25.61. 12 Rose. P. A. 75.403. SPECIFIC GA VITY TABLES. 23 Melting Name. Specific Gravity. Boiling Point. Point. 1Tungsten. I 654-) 2 1 I7-50~. 3 18 I8.26. (( I7. -I7.3. Red. by H. 6 (1 I7.9-18.12. (( C. 6 i6.6. )Prepared by (7 I7.2. three differ8 18.447, 17.0 ent methods. 9 Zinc. 6.86i. 10 ( 6.862. I ( I 412.0 12 6.9154. 13 (( 6.869. 6.992. 6.956. 14 423.o 13 7.03-7.20. 16,, 6.966-6.975, 12.~ 17 I40.~ s18,,7.2I. 19,7. I 46. 20 (( 6.895. 21 M( Melted. 6.522. 6.511. 6.504. 22 Cadmium. 8.604. 23 (( 8.670. 24 8(.650. 25 (( 8.6355. 26, 31 5.0 27,, 320.0 28 (( 320.0 29 860.0 30 0 8.655, 11.0 31 ((8.54, ) 32 (( 8.566, Pure. (33 { 8.667, 34,1 8.648, commercial. AUTHORITIES. 1I v. Uslar. 8.372. 13 Playfair and Joule. 11. 25 Karsten. 3. 2 v. Uslar. 8.372. liPerson, 1.73. 26B. Wood. Watts' Dicv. Uslar. 8.372. 15 Bolley. 8.387. tionary. 4 { Bernoulli. 13.152. 16 Schiff. A. C. P. 107.59. 27 Person. Watts' Dictionary. 5 Bernoulli. 13.152. 17 Deville and Troost. 12.25. 28 Rudberg. 1. 6a Zettnow. 20.218. 18 Daniell. 29 Deville and Troost. 12.25. 7 Zettnow. 20.218. 19 TWertheim. 30 aIatthiessen. 13.112. 8 Zettnow. 20.218. 20 MNallet. Ding. J. 85.378. 31 Schr6der. 23. 9 Brisson. See 11. 21 Playfair and Joule 11. 32 Sehrdder. 23. 10 Berzelius. See 11. 22 Stromeyer. See 11. 33 Sehroder. 23. n Daniell. 35. 23 Children. See 11. 34 (Schr6der. 23. 12 Karsten. 3. 24 Herapath. 1. 24 SPECLIFIC GRA VITY TABLES. Melting Name. Specific Gravity. Boiling Point. Point. I Magnesium. 2.24. 2 (( I'.7430. 5'. 3 I.69-I.7I, I7.0 4 1.75. M5 ercury. Solid. I4.391. 6 (( ( I4.485,-60.0 (( (( I14.0, a. 8 (( 15.19. (( Liquid. I3.568, I5.c 5. 346.05. 10 (( 356.025. 11 (( 3.613, 10.0 12 (( 349.0 3 (( (( 13-568. 14 (( 13.575. 15 (( -39.~44. 16 (( 360.0 17 (( 13.5886, 4.~ 18 e o 1I3.535, 26.0 19 ( I3.-588597. 20 I3- 5592. 21 i3.59599. 22 (( I3.59602. ~0.~ 23 (( 13.59578.- 24 (( (C 13-595, 0.0 25 (( ( I3573, 15.0 26 (( 357.025. 760m.m. 27 ( I3.6o 3, 12.0 28 (( I3.569, 16.~6. 29 Nitrogen. 30 Boron. 2.68. Crystallized. 31 Phosphorus. 250.0 32 (( 288.0 33 (( 290.0 AUTHORITIES. 1 Playfair and Joule. 11. 1' Fahrenheit. a 23 Regnault. A. C. Phys. 2Bunsen. 5.363. 1j Hutchins. Watts' (2). 14.236. 3 Kopp. See 23. 16 Dulong and Petit. it. 24 Kopp. 1.445. 4 Deville and Caron. 10.148. 17 (Kupff'er. A.C. Phys. (2). 25 Holzmann. 13.112. 5 Schulze. 40.285. 40.285. 26 Regnault. 16.70. 6 Biddle. P. MAI. 30.153. is Kupffer. A. C. Phys. (2). 27 Schiff. 7 Kupffer & Cavallo. See 11.'9 Biot and Arago. Biot's 2sB. Stewart. 8 Joule. 16.283. "Traite de Physique." 30 oWhlerand Deville. A. C. 9 Crichton. P. M. 16.48. 20 Karsten. 3. Phys. (3). 52.63. 10 Heinrich. Schw. J. 1.214. 21 Regnault. A. C. Phys. 31 Heilrich. tts' 1 Biddle. P. M. 30.152. J (2). 14.236. 32 Dalton. Dictioary. 12 Dalton. J:n 22 Re,,rnault. A. C. Phys. 33 Pelletier. 13 Caveiidish &; Brisson. (2). 14.236. SPECIFIC GRAVITY TABLES. 25 Formula. Specific Gravity. Boiling Point. Melting Point. 1Phosphorus. Common. I.77. 2 (( (( 2.09. 3 (( (( I.800. 4 (44.2. (1 44.02. 5 (( (( 6 ( (.826-I.840, I0.0 c7 ic ( 1.8262-1.8265, Io.O 8 (1 I.823, 35.0 9 (( 3Melted. 1.744. 10 s. I.88, 45.0 11 Cooled below melt1.763, 1 ing point. 12 Red. 1.964, IO.0 13 o (( 2.o89-2.106, 17.0 14 2u (( 2.I4. Crystallized. 15 (( 2.23.5Two preparations. 16 ct 2.34, I5.~5. "Metallic." 17 Vanadiufn. 5-5, I5.0 1s Arsenic. 5.763. 19 5.766. 20 (( 5.76321 5.884. 22 5.700-5.959. 23 5.672. 24 I 5.6281. 25 3 ( 5.736, native. 26 (( 5.722-5.734, native. 27 (( 5.230. 28 5.395, I2.'5. 29 5.726,-5.728, I4.~ 30 Fused. 5.709, I9.0 31 Amorphous. 4.7o1-4.7I6, I4.~ 32 Antimony. 6.702..33 6.712. 34,, 6-733. AUTHORITIES. 1 Berzelius. Watts' Diction- 11 Gladstone and Dale. 12.73. 23 Herapath. 1. ary. 12 Schr6tter. 1.336. 24 Karsten. 3. 2 Bottger. Watts' Diction- 13 Schr6tter. 3.262. 25 Breithaupt. J. F. P. 16'475. ary. 14 j Brodie. 5.330 and 331. 26 Ireithall pt. J. F. P. 1t.151. 3 Playfair and Joule. 11. 15 Brodie. 5.330 and 331. 27 Playfair and Joule. 11. 4Person. 1.80. 16 Hittorf. 18.130. 28 rLudwig. 12.183. 5Desainsi 1.84. 17 Roscoe. P. T. 1869. 679. 29 Bettendorf. 20.253. 6 Schrotter. 1.336. 18 Brisson. I 30 Mallet. B. S. C. 18.438.. 7 Kopp. A. C. P. 93.129. 19 Mohs. 31 Bettendorf. 20.253.. 8 Gladstone and Dale. 12.73. 20 Stromever. See 11. 32 Brisson. 9 Playfair and Joule. 11. 21 Turner. 33 Hatchett.. See 11.. 10 Schritter. 1.336. 22 Guibourt. B6ckniann. 2 Gubut.aBckan 26 SPECIFIC GRAVITY TABLES. Name. Specific Gravity. Boiling Point. Point'Antimony. 6.852. 2 o 6.86o, (3 6.646. ((4 e6.6io. c5 6.7006. 6 (( 6.715. 7,, g06.707-6.718; 170 to 2I.~ c8 6.713, I4.0 cc9 6.697. 10 I 450o.0 c11 ~ Melted. 6.646-6.529. 12 Amorphous. 5-74-5.83-3 Bismuth. 9.67. 14 9.822. 15 9.800. 16 C 9.882. 17 CC 9.8827. 18,, 9.83I. 19 (C 9.6542. 20 C( 9.799, I9~, pure. 21 9.783, commercial. 22 s( 9.556, after great pressure. J 23 268.03. *24 (C 270.0 25 264.0 26 9.935, crystallized. 27 9.677, quickly cooled. 28,, 9.823, 12.~ 29 Melted. 9.81,9.756,9.905,9.72 I. 30,, 9.759, 9-70I, 9.680. 31 Gold. I9.258. 32 19.207, hammered. 33 1, I9.3-1I9.4. AUTHORITIES.'VMuschenbroek.'3 Muschenbroek. 22 Marchand & Scheerer. J. 2 Bergmann. 14 Brisson. See 11 F. P. 27.193. 3-Mohs. See 11. 15 Leonhard. e 23 Rudberg. 1.71.;4 Breithaupt. J 16 Thenard. 24 Person. 1.72. 5Karsten. 3. 17 Berzelius. See paper of 25 Watts' Dictionary. 6 Marchand & Scheerer. J. Marchand & Scheerer. 26 I C. St. Claire Deville. 8.15. F. P. 27.193. 18 Herapath. 1. 27 C. St. Claire Deville. 8.15. 7 Dexter. 10.210. 19 Karsten. 3. 28 Holzmann. 13.112. 8Matthiessen. 13.112. 20 0Marchand&Scheerer. J. 29 Playfair and Joule. 11.'9 Schr6der. 23. F. P. 27.193. 30 Schroder. 23. 10 Watts' Dictionary. 21 Marclhand & Scheerer. J. 31 Brisson. See 11. 1I Playfair and Joule. 11. F. P. 27.193. 32 Elliot. } See Rose's paper.:AtGore. 13.1Z2. 33 Lewis. SPECIFIC GRAVITY T'ABLES. 27 Name. Specific Gravity. Boiling Point. Melting Point. 1 Gold. I 2oo00.0 2 (( I380.0 3 11 II44.0 4 (I93336, I7-05, pressed. cI 1705. Precipita65 (e |I9'7439'?ted with Fe SO4. 20.6882.) Extremes of8det. 7 o I9479I.;Precip. by oxalic 8 I9.494I. ( ( 9 t I9.265, I3.~ 10 Carbon. Dianmond. 3. 55. 11 3.492. 12 3.520. 13 V ( 3.334 14 (( 3-5lam(( o nd 3-55o 13 3.55. 16 C~ 3.5295. cc7 c( 3.53. From Bohemia. 18 Graphite. 2. 14. 19 ( 2.229. 20 2.273. 21 2.14. 22 2.5. 23 c 2.3285. 24 2c 2.3 62. 25 ic 1.802. ) 20.0 26 (C I.844. 5 Purified. 27 C (C 2.25-2.26. 28 0 2.05. ) Extremes of 29 determinations, of samples 29 ( (( 2.5853. fr. different localities. 30, Gas Carbon. 1.885. 31 Silicon. Graphitoidal. 2.49, I0.0 32 c 2.493. 33 ( 2.004. 2.194 2.197. AUTHORITIES. Pouillet. atts 3 Shepard. See 27. 4 Poggendorf. P.A. Erganz. 2Guyton-Morveau. Dic " I Berzelius. A. C. P. 49.247. bd. 1848. 363. 3Daniell. 34.. Pelouze. Watts Die- 25 Lwe. 8.297. 4 G. Rose. P. A. 73.1. 16 Thomnson. } tionary. 26 L6we. 8.297. 5 I G. Rose. P. A. 73.1. 17 Schafarik. P. A. 139.188. 27 Brodie. 12.68. 61 G. Rose. P. A. 73.1. 80Breithaupt. ) 28 Mene. 20.972. 7 L G. Rose. P. A. 73.1. 19 Kenngott. See 27. 29 Miend. 20.972. 8G. Rose. P. A. 75.403. 20 Regnault. j 30 Men6. 20.972. 9Holzmann. 13.112. 21 Fuchs. J. F. P. 7.353 31 Whler. 9.347. 10 Brisson. 22 Berzelius. A. C. P. 49.247. 32 Harmenhig. See 23. 11 Grailich. See 27. 23 Karsten. 3. 33 Winkler. 17.2s08 and 209. 12 Mohs. 1 28 SPECIFIC GRA VITY TABLES. Pn Melting Name. Specific Gravity. Boiling Point. Poin. I Titanium. 2Tin. 7.29I. 3 (( 7.295. 4 (( 7.278,I5.-5. s. 238.0 7.29I, I7.0 ( 7. 285. 7.600oo. 7 (( 7.5565, cast. 8 ( 228.0 9 (( 7.2905. 10 ( 7.245.7.363.7.330 7.288 1(( 228.05. 12 (( 235.0 13,, 7.I78, crystallized. 14 -. 7.293, cast. 7.3043. 16,, 7.239. 7-373. 1 ((C 7.294, I3.0 18 (( 7.291. 19 A( Mfelted. 6.949. 6.9I3. 6.940. 20 Zirconium. 4 I 5 21 Aluminum. 2.50, cast. 22 (( 2.67, hammered. 23 Glucinum. 2.I. 24 Lanthanum. 25 Didymium. 26 Cerium. 5.5, I 2. 27 Yttrium. 28s Erbium. 29Thorium. 7.657. 7.795. 30 Tantalum. I0.08-I0.78. 31 Niobium. 6.0-6.6. Contains 32 (6. I 5-7.37. hydrogen. AUTHORITIES. 2 Brisson. See 11. n Rudberg. 1.71. o 9 Playfair and Joule. it. 3 Muschenbroek. See 11. 12 Person. 1.71. 20 Troost. 18.183. 4 Crichton. P. M. 16.48. 13 iW. H. Miller. P. M. (3). 21 { W6hler. 7.327. 5Kupffer. A.C. Phys. (2). I 22.263. 22 Wohler. 7.327. 40.285. 141 W. H. Miller. P. M. (3). 23 Debray. 7.336. 6 Herapath. 1. 22.263. 26 Whler. A. C. P. 144.251. 7 Herapath. 1. 15 Kopp. A. C. P. 93.129. 29 Chydenius. 16.194. 8 Daniell. 34. 16 C. St. Claire Deville. 8.15. 30 Rose. 9.366. 9 Karsten. 3. 17 Matthiessen. 13.112. 31 Marignac. 21.214. 10 Playfair and Joule. 11. 18 Mallet. Ding. J. 85.378. 32 1 Marignac. 21.214. SPECIFIC GRAVITY TABLES. 29 II. FLUORIDES. INORGANIC. Name. | Formula. 1 GSpecific Boiling Melting Nam._ormla Gravity. Point. Point. Hydrogen fluoride. 1. H F..9885, I3.06., 2 (( 1. (c I.036, I 5.~5.::3.( (1. ((.9922, I I.~ 4 (1 ( 1. ((.9879, I2.07. 5 i( o 1. (( I.0609. 6 Potassium c( K F. 2.454, I27 Silver ( Ag F. 5.852, I505. 8 Calcium ~ Ca F2. 3 I 83. m. of 6o. 9 ( 3.I5. American. 10 ( oC 3.138. 11 CC (( 3.162. Very pure. 12 Barium n Ba F2. 4.58, I3.0 13 Aluminum A12F6 3Fo65. 3.o65.}12.~ 14 3.13. -1 Arsenic trifluoride. As F3. 1. 2.73. 63.0 16 Fluocerite. Ce F2. Ce2 F6. 4-7 "7Hydro ammonic fluoride. Am H F2. 1.211, I2.0 18 Potassio titanic,e 2 K F. Ti F4. 2.0797, I2.0 19 Cryolite. Greenland. 3 Na F. Al F3. 2.90-3.077. 20 (( Miask. CC 2.692. 21 (( C( " 2.95. 22 Chiolite. 3 Na F. 2 Al F3. 2.72. 23,, (( 2.90. 24 2.842.-2.898. 25 Chodneffite. 2 Na F. Al F3. 3.003.-3.077. 26 2.62-2.77. AUTHORITIES.' Gore. Phil. Trans. 1869. 8 Kenngott. 6.853. 19 Dana's Mineralogy. 173. 9 J. L. Smith. 8.976. 20 Kokscharow. 4.820. 2 Gore. Phil. Trans. 1869.' Schiff. 21. 21 Durnew. 4.820. 173. 11 Luca. 13.98. 22 Hermann. J. F. P. 37.188.:3 Gore. Phil. Trans. 1869. 12Bddeker. 26. 23 Kokscharow. 4.820. 173. 13 5 B6deker. 26. 24 Ranmelsberg. P. A. 74. 4 Gore. Phil. Trans. 1869. 14 B deker. 26. 314. i 173. 15 UInverdorben. P. A. 7.316. 25 Ramllmelsberg. P. A. 74. 5 H. Davy. Phil. Trans. 16 Dana's Mineralogy. 314. 1813. 263. 17 B1deker. 26. 26 v. Worth. Dana's Miner6Bsdeker. 26. 18 B6deker. 26. alogy. 7Gore. Chenm. News, 21.28. 30 SPECIFIC GRA VITY TABLES. III. INORGANIC CHLORIDES. 1st. ANHYDROUS SIMPLE CHLORIDES. Name. Formula. Specific Boiling Melting Gravity. Point. Point.'Hydrogen chloride. H Cl. 1. 1.27. 2 Iodine mono chloride. I C1. 25.0 3 Iodine tri chloride. I C13. 20 — 25.O 4 Lithium chloride. Li C1. I.998. (5 ( (( 2.074. 6 Sodium Na C1. 2.030. (( (( (( 2.15.;8 (( (( 2.200I. (9 (c o( 2.078. 10 (( (( 2. 150. 11 ( 2.OI I. m. of 3. 12 (( 2.26. 13(( (( I 2.24. 14 ( 2.204.'1 (1 2.195.) 16 if 2.1I42. t 17 uC 2.207. ( Native. 1s8 (s 0 2.1I35. Pure. 9 ( ( 2. 48. 20 0 (( 2.153. 21 C 2.1 6 I. 22 (( 2.145. 23 2.1629, 15-. 24 (( (( (( 2.15432' Potassium " K C1. I.836. 26 0 (( 1.9I53. 27 C (( (C I.945. 28 cc (( 1.9367. AUTHORITIES. 1 Watts' Dictionary. 10Kopp. 5. 201 Schr6der. 23. 2 Watts' Dictionary. 11 Playfair and Joule. 11. 21 Schr6der. 23. 3 Watts' Dictionary. 12 Mohs. See 23. 22 Buignet. 15.14. 4Kremers. See 23. 13 Filhol. 12. 23 Stolba. J. F. P. 97.503. s Schr6der. 23. 14 Deville. See 23. 24 Haagen. 32. 6 Unger. See 23. 15 Deville. See 23. 25 Kirwan. 7 Leslie. 16 Grassi. 1.39. 26 Karsten. 3. 8 Hassenfratz. A. C. Phys. 17, Grassi. 1.39. 27 Kopp. 5. 28.3. 18 T. S. Hunt. 8.976. 28 Hassenfratz. A. C. Phys. 9 Karsten. 3.'9 Schiff. 21. 28.3. SPECIFIC GRAVITY TAB'LES. 31 Name. 1 Formula. Specific Gravity. Boiling Melting Point. Point. 1 Potassium chloride. K C1..9oo. 2 I,97756, 4.0 3 1I. 994. o(C( ~I-995o ( (( I-9956 ( o(C I1.986. 7 01o (( I.94526, I5.~ 8 Ammonium (( N H4 C1. 1.450. 9 C c c(( I.54425. 10 (( I. 528. 11.578. m. of 3. 12 (( (( (( 12 I1.5333- 4.0 13 (( (5o. 14 cc cc( I. 522. 15 ( (( 1.550. 16 IC c 1.5033. ) 17 I.519 I. 15. 18 (( ( (c I.5209. 19 Silver " Ag C1. 5.4548. 20 (( ( (c 5 I 29. 21 5.4582. Fused. 22 (( (( (( 5.567 I. Blackened. 23 (C 5.50I. Unfused. 24 Co 5.548. 25 (( 5-5526 ( 5.31. Native. 27 ((Te< 5.43-) 28 C( C 5-517. 9 (( (( 55943 30 260. 31 Thallium chloride. T1 C1. 70oo. 32 (( 1 c cc 7.02. 33 260.0. 23 (( (( (( 260.0~ 34 i( sesqui chloride., T12 C13. 5.9. AUTHORITIES. Plavfair and Joule. 11. 13 Kopp. 5. 24 Boullay. 2. 2 Playfair and Joule. 14. 14 Schiff. 21. 25Gmelin. See 27. 3 Filhol. 12. L5 Buignet. 14.15. 26j Domeyko, 4 Schiff. 21. 16 ( Stolba. J. F. P. 97.503. 27 See Dana's Mineralogy. 5 Schr6der. 23. 17 Stolba. J. F. P. 97.503. 28 Scliff 21. 6 Buignet. 14.15. 8 ( Stolba. J. F. P. 97.503. 29 Schrbder. 23. 7Stolba. J. F. P. 97.503. 19 Proust. See 23. 30 Watts' Dictionary. 8 Wattson. See 23. [28.3. 20 Herapath. 1. 31 W7ilm. 9 Hassenfratz. A. C. Phys. 21 K Iarsten. 3. 32 Lamy. 15.184. 20 Mohs. See 23 or 27. 22 J Karsten. 3. 3 iatts Dictionary. 1 Playfair and Joule. 11. 23 ( Kaxsten. 3. 34Lamy. 15.184. 12 Playfair and Joule. 14. 32 SPECIFIC GRAVITY T4BLES. Name. Formula. GravSpecific Boiling Point. Melting Gravity. Point. For compounds of C1l and 0, see oxides. 2 Sulphur chloride. S2 Cl2. I.687. 1. 138.0 3 ( 1i.686. 1. I39.0 4, cc I.6802.I667.1. } 5 (C ( 1 I.7055-0.o 144.~ 6 I ( 136.~ 760 m. m 7 c (( (c< I.6828, 20.0 1. I3777. 76.4 8'Marchand and Dumas [m. m. also obtained a mix- Mixture 1.625. 1. Variable. ture which they sup- near S C12. 1.62. 1. 64.~ posed to be S C12. 9 Calcium chloride. Ca C12. 2.2 4. o10 (0 c 2.269.) 11 CC ( CC 2.040 I. 12 (C (C CC 2.480. 13 CC C( 2.240. 14 2.205. 15 Strontium chloride. Sr C12. 2.8033. 16 CC 2.960. 17 Barium o Ba C12. 3.860. cc18 CC 4.I 56.) 19 3.8. 20 C CC 3.7037. 21 C( (( 3.750. 22 3.820. 23 3.872. 24 c( (c 3.886.) 25 Lead R Pb Cl2. 5.29. 26 5.238. Native. 27 RC c, 5.6824. Fused. 28 RC CC (( 5.8022. Not." S 29 5.802. Cryst. 30" 5.78. AUTHORITIES. 2Dumas. A. C. Phys. (2). 9 Boullay. 2. 2o Karsten. 3. 49.204. 10 Boullay. 2. 21 Filhol. 12. 3 Marchand. J. F. P. 22.507. 1n Karsten. 3. 22 Schiff. 21. 4f Kopp. 17. 12 Playfair and Joule. 11. 23 Schr6der. 23. 5 Kopp. 17. 13 Filhol. 12. 24 Schrbder. 23. 6 Chevrier. C. R. 64.302. 14 Schiff. 21. 2j Monro. See 7. 7 Haagen. 32. 15 Karsten. 3. 26 Daina's Mineralogy. 8 Marchand. J. F. P. 22.507. 16 Filhol. 12. 27 f Karsten. 3. Dumas. A. C. Phys. (2). 17 Boullay. 2. 28 Karsten. 3. 49.204. 18 V Boullay. 2. 29 Schabus. 3.322. 19 Richter. See 21. 30 Schiff. See 23. SPECIFIC GRA VITY TABLES. 33 Name. Formula. Specific Gravity. Boiling Point. Melting Point. Lead chloride. Cryst. Pb C12. 5.80534, I5.0 2 Chromic chloride. Cr2 C16. 3-03, I7.~ Cryst. 3 Ferrous o Fe C12. 2.528. 4 Nickelous Ni Cl2. 2.56. 5 Cobaltous, Co C12. 2.937. m. of 3. 6 Cuprous Cu C1. 3.6777. (7 o, 3-376. - Cupric cc Cu C12. 3.054. 9 Platinous (c Pt C12. 5.8696, I I.~ 10 Tungsten hex chloride. W\ C16. 2 I8. " Zinc chloride. Zn Cl2. 2.753, 13.0 12 A agnesium chloride. Mg C12. 2.I77. m. of 2. 13 Cadmium o Cd CI2. 3.62 54, I2.~ 14M Mercurlous " Hg C1. 7.1I758. 1 (( (( (( 7.4 16 (1 cc( 6.9925. 17 (( 6.7 I07. s18 (( cc 6.482, Native. 19 ( 7.178. 9 (( (( (( 7 20 (( 6.56. 21 nMercuric oc Hg C12. 5.I4. 22 (( 5I 398. 23 (( (( (( 23 ( 5.42. a2 (C 5.4032. 25 (C 295.~ 265. 26 6.223. 27 o 5.448. m. of 3. 28 Nitrogen trichloride. N C. (?) 1.653. 1. 29 Boronll B C]3. I-35 1. I7.~ 760 m. m. 30 Phosphorus P C13. I.45. ax,,,(,, I.6I6I6, o.0.~ 78-34- 75I.5m.m 32 C C C 1. 8.~ 7 63 m. m. 33 1. 787 85. 760 m. m. AUTHORITIES. 1 Stolba. J. F. P. 97. 503. l3B6deker. 26. 23 Boullay. 2. 2 Schafarik. 28. 14 Hassenfratz. A. C. Phys. 24Karsten. 3. 3 Filhol. 12. 28.3. 25 Watts' Dictionary. 4 Schiff. 21. 15 Boullay. 2. 26 Playfair and Joule. 11. 5 Playfair and Joule. 11. Karsten. 3. 27 Schr6der. 23. 6Karsten. 3. 17 Herapath. 1. 28 Watts' Dictionary. 7 Playfair and Joule. 11. 18 Haidinger. Dana's nMin- 29 W6hler & Deville. 10.931. 8 Playfair and Joule. 11. eralogy. 30 H. Davy. See 17. 9 BSdeker. 26. 19 Playfair and Joule. 11. 31 Pierre. 15, or 45. 10 Riche. 9.373. 20 Schiff. 21. 32 Dumas. See 17, or 29. o Bddeker. 26. 21 Gmelin. See 7. [28.3. 33 Andrews See 17, or 29. 12 Playfair and Joule. 11. 22 Hassenfratz. A. C. Phys. I 34 SPECIFIC GRA VITY TABLES. Name. Formula. Specific Gravity.' Boiling Point. Meltint. Point. 1 Phosphorus trichloride. P C13. 1. 73 8. 760o n. m. 2 (( (t (( I.61 9,o.~ m. of 2. (3 (C (C 1.59708, IO.~ 76.0 760om. m. 4 (C (C (C I.47124,76.~m.of 3. 6 (( 1( ( I.5774, 20.~ 76.0 745.9 m. m. 6 (, pentachloride. P C15. 148.0 7 Vanadium dichloride. V C12. 3.23, I8.0 S. 8,, trichloride. V Cld. 3.00, I8.0 s. 9,, tetrachloride V C14. 1. I.8584, 0.0 10 CC. < (( 1. I.8363, 8.0 I54.0 760 m. m. 11 CC <( 1. I.8I59, 32. 12 Arsenic trichloride. As C13. I32.0 13 1. 2.20495, 0.0 I33'8I. 756.9 14(( 1. 2.1766. [m. m. 15 CC (C 1. 2.1668, 20.0 I28.0 754 m. m. 16 Antimony (C Sb C1l. I98.0 17 (((. 230.0 72.~ 18 ( ( 1 l. 2.675, 73.0 2. 223.0 760 m.m. 73~2. (( pentachloride. Sb C15. 2.3461. 20.~0 20 Bismuth trichloride. Bi C13. 4.56, I I. 21 Carbon dichloride. 2 C14. I.6I9, 20.0 I22.0 22 CC (( I.649, o.~ I23.9. 76I.9m.m 232 ( (( I.6I2, I0.0 116~7. 24 trichloride. C2 C16. 2.0. I82.0 I60. 25 tetrachloride. C C14. I.599. 78.0 26 C( e I *56. 77-0 27 C C I.62983, o.~ 78~1. 748.3 m.m 28 ( (C ( I-567, I2.0 77.0 (29 ( Co I.5947, 20.~ 75~5. 739.4m.m ~ 0 Silicon trichloride. Si2 C16. 1.58, 0o. I46.~-I 48.0 31 (( tetrachloride. Si C14. 50.~ 2 ( o2 (( 1.52371, 0.0 59.0 760 m. m. (C 9 33C 1.4878, 20.~ 58.0 756 m. m. AUTHORITIES. 1 Regnault. See 29. 13 Pierre. 15, or 45. 24 Watts' Dictionary. 2 {H. L. Buff. 29. 14 Penny & Wallace. 5.382. 25 Regnault. A. C. Plhys. (2). 3 H. L. Buff. 29. 15 Haagen. 32. 71.383. 4 ( H. L. Buff. 29. 16 Davy. See 17. 26 Kolbe. A. C. P. 54.146. 5 Haagen. 32. 17 Capitaine. J. F. P. 18.449. 27 Pierre. 15. 6 Strecker's " Lehrbuch." s8 Kopp. 18. 28 Riche. 7 Roscoe. P. T. 1869. 679. 19 Haagen. 32. 29 Haagen. 32. 8 Roscoe. P. T. 1869. 679. 20 B6deker. 26. 30Troost & Hautefeuille. Z. 9 Roscoe. P. T. 1869. 679. 21Regnault. A. C. Phys. (2). F. C. 14.331. 10 Roscoe. P. T. 1869. 679. 71.353. 31 Serullas. See 17. 1 ( Roscoe. P. T. 1869. 679. 22 I'ierre. 15. 32 Pierre. 15, or 45. 12 Dumas. See 17. 23 Ceutller. A. C. P. 107.212. 3 HIaagen. 32. SPECIFIC GRA VITY TABLES. 35 Name. Formula. Specific Boiling Melting Gravity. Point. Point.'Silicon tetrachloride. Si C1,. I.4928, I5.~ (2 o ( 1( I.49276. 3 (( oI.5o068, Io? 98. 4 I 1.522, 0.0 5 Titanium ", Ti C14. 1.76088, o.~ I 36.~ 762.3 m.m 6 (( 6c. 135-0 7 Tin protochloride. Sn C12- 250.0 8 " tetrachloride. Sn C14. 2.26712, o.~ II5~4. 753-Im.nl 9 ( 9 (9 cc I20.~ 767 m.m. 10 1( (( o( I 1275. 752 m.m. 11 cc c( 2.234, 15.0 12 (( ( (2.2328, 20.0 162.0 754.9m.m 13 Aluminic chloride. A12 C16. I8o.~'1 Niobic (( Nb C1l. 240~5. I94.0 15 Tantalic o Ta C15. 2416. 753 m.m. 2 I 1.~ 3. 16 Tungsten pentachloride. WV C15. 275o6. 248.cS.242., 17 hexchloride. X Cl6. 346?7. 275.CS.270.~0 2d. HYDRATED SIMPLE CHLORIDES. Name. Formula. vSpecific Boiling Melting Gravity. Point. Point. 18 Calcium chloride. Ca C12. 6 H2 O. i.68o. m. of 2. 19 (C o o I1.635. 20 i( 1.612, I0.0 29~0 21 Strontium (" Sr C12. 6 H O. 2.0I 5. m. of 2. 22 ( 1.603. 23 ( ( I.92 I. 26 Barium Ba C12. 2 H2 O. 3. I44. m. of 2. 25,, (( (( 2.664. zs26 CC 3.05435, 4'0 27 CC (( (( 3.052. AUTHORITIES. 1 Mendelejeff. 13.7. 10 Andrews. See 17. 19 Filhol. 12. 2 3Iendelejeff. C. R. 51.97. n1 Gerlach. 18.237. 20 Kopp. 8.44. 3 Mendelejeff. (?). 12 Haagen. 32. 21 Playfair and Joule. 11. 4 Friedel & Crafts. S. J. (2). 13 Liebig. Watts' Dictionary. 22 Filhol. 12. 43.162. 14 Deville and Troost. 23 Buignet. 14.15. 5 Pierre. 15, or 45. 15 Deville and Troost. 24 Playfair and Joule. 11. 6 Duppa. P. A. 97.510. 16 Roscoe. Chem. News. 25.61. 25 Filhol. 12. 7 Watts' Dictionary. 17 Roscoe. Chem. News. 25.61. 26 Playfair and Joule. 14. 8 Pierre. 15, or 45. 18 Playfair and Joule. 11. 27 Schiff. 21. 9 Dumas. See 17. 36 SPECIFIC GRAVITY TABLES. Specific Boiling Melting ___________Name _ _ _. Formula__. Gravity. Point. Point. Barium chloride. Ba Cl2. 2 H2 0 3.o8i. 2 Manganous chloride. Mn C12. 4 H12 0. I6.~ 8705. 3 2.0I, I0.0 4Ferrous ( Fe Cl2. 4 H2 0. 1.926. (( (( (( I.937. 0 Cobaltous Co Cl2 6I-2 0. 1.84. 13.0 Cupric (( Cu Cl2. 2 H112 0. 2.535. m.of2. 8 " 2.47, I8.~ A9Magnesium Ag Cl2. 112 O. I.562.m.of 4. 10 1.558. 11 Stannous Sn Cl2. 2 H2 0. 2-759. S. (12. {2.71. 15"5. S. 13 (( (c (( 13 2.5876,37?7'1 14 ( Sn Cl2. 4 H20. 0 15 Platinic Pt C14. 8 H2 0. 2.431, 15.0 50. 3d. ANHYDROUS DOUBLE CHLORIDES. Excluding Compounds of Oxychlorides. Name. Formula. Specific Boiling Melting Gravity. Point. Point. 16 Potassium zinc chloride. 2K Cl. Zn Cl2. 2.297. 7 Ammonium zinc chloride. 2 N H4 Cl. Zn C12. [.879. 18 I.72-I.77, 100 19 Potassium platinchloride. 2 K CL Pt Cl4. 3.586, 15.0 20 Cc oC 3.694. 2'Ammonium (( 2NH4 Cl. Pt C14. 2.955. 15.0 ~~~~~22 (C ~~~~~~3.o009.) I 23 2.96o. (( (C 2.960. 24 Potassium iridochloride. 2 K Cl. Ir Cl4. 3.546, I 5. 25 Ammonium ( 2 N -14 Cl. Ir Cl4. 2.856, I5.~ 26 Caesium stannochloride. 2 Cs Cl. Sn Cl4. j3.3308,20. 5. AUTHORITIES. 1Buignet, 14.15. 10 Filhol. 12. 19 B6deker. 26. 2 Watts' Dictionary. 11 Playfair and Joule. 11. 20 Tschermak. 27. s Bdeker. 26.'2Penny. C. S. J. 4.239. 21 Bi6deker. 26. 4Filhol. 12. 13 Penny. C. S. J. 4.239. J 22 B1gdeker. 26. 5Schabus. 3.327. 14 Watts' Dictionary. 23 Tschermak. 27. 6 B1deker and Ehlers. 26. 15 Bodeker. 26. 24 Bbdeker. 26. 7 Playfair and Joule. 11. 16 Schiff. 25. 25 Bideker. 26. s Bbdeker. 26. 7 Schiff. 25. 26 Stolba. Dingler's J. 198. 9 Playfair and Joule. 11. 18 Bsdeker and Ehlers. 26. 225. SPECIFIC GRA VITY TABLES. 37 Specific Boiling Melting Gravity. Point. Point.' Sodium aluminum chloride. 2 Na C1. A12 C16. I85.~ 2 Selenium phosphorus,c Se C14. 2 P C15. 220.0 3Iron Fe2 C16. 2 P C15. 280~+. 98.0 4 Alumninum *U c A12 C16. 2 P C16. 400.0 6Silicohydric {( Si3 H4 Clo. I.65. 42.0 4th. HYDRATED DOUBLE CHLORIDES. Name. Formula. Specific Boiling Melting Gravity. Point. Point. 6Potassium iron chloride. 2 K C1. Fe C12. 2 H2 0. 2.I62. 7, copper (( 2 K C1. Cu C1. 2 11, 0. 2.426. 8 O 0 C (( O 2.400. 9,( Vc c( 2.359. 0 ( 2.410. A11Ammonium o o 2 N H4 C1. Cu C,2H. 2 H2 O. 2. 8. 12 CC (C 1.963. 132 (( o( C(1 I.977. 14 V C Co 2.o66. 5 (( magnesium (( N H4 C. Mg C12. 6 H O. I-456, IO.~'6 Sodiuln mercury. Na C1. Hg C12. 2 H,, O. 3.011. 1" Potassium o, ( K C1. Hg C2. 112 0. 3.735.m.of3. 01 Ammonium ( 2 N 1H4 C1. 2 Hg Cl. H1120. 3.822. 19' " 2 N H4 C1. Hg Cl2. 11 0. 2.938. 20 Potassium tin 2 K C1. Sn Cl2 3 112 0. 2.5I4. 21 Ammonium tin, 2 N H4 C1. Sn C1,. 3 112 0. 2. 04. 5th. OXY- AND SULPHO-CHLORIDES. Name. Specific Name. Formula. Specific Boiling Point. Melting Point. Gravity. 22 Thionyl chloride. S 0 Cl2. 82.0 23 1.675, 0.0 78.0 24 Chlorosulphuric acid. S2 05 C1l. i.8I8, I6.0 145.0 25 II (C (C 1.762. I45_-I 50.0 AUTHORITIES. 1 Deville. 7.332. 10 Tschermak. 27. 18 Playfair and Joule. ) 2 Baudrinlont.) 11 Playfair and Joule. 11. 19 Playfair and Joule. 3 Baudrimont. 15. 54. 12 Schiff. 25. 20 Playfair and Joule. 4 Baudrinmont. 13 Kopp. 11.10. 21 Playfair and Joule. J 5 Buff and W6hler. 10. 168. 14 Tschermak. 27. 22 Schiff. 10. 105. 6 Schabus. 3. 327. 15 B6deker. 26. 23 Wurtz. J. F. P. 99. 255. 7 Playfair and Joule. 11. 16 Playfair and Joule. 24 H. Rose. P. A. 44. 291. 8 Schiff. 25. 17 Playfair and Joule. J 2 Rosenstielhl. 14. 121. 9 Kopp. 11. 10. SPECIFIC GRAVITY TABLES. Name. Formula. Specific Boiling Melting Gravity. Point. Point. 1 Selenyl chloride. Se 0 Cl2. 2.44. 220.0 [mm. 2, (t 2.443, I3.0 I7905. 760. IO.~ rs, o.0 s Chlorochromic acid. Cr 02 CI2. 1.9I34, I0.'0 m.m. 4 I( ( (( 1.71, 21.~ 118? 760 5 (( (( 1t I.92, 25.0 I I678. 733 6Tungsten oxychloride. W 0 C14 227*5. [mm. 210~4. S.206~7. [For native mineral oxychlorides. See Table of Miscellaneous Compounds.] 7 Nitrosyl chloride. N 02 C1. 1.32, I4.0 8 Phosphorus oxychloride P 0 C13. 1.673, I4.0 IIO.0 9 (( (.70, 12.0 I0. 10o.( ( 1.662, I9.5. [of2. 21 I.6937I, IO.0 m. 12a C (C I.69IO6, I4.0 13 cc (C 1.68626, 15.~ I110.0 14 C CC I 1.64945, 5 I. 760o m.m 15 i.( 1.5091 I6, I II0. 26 ((T.66. Lm. of 5. I I0.'7Vanadyl dichloride. s. V 0 Cl2. 2.88. 13.0 s.'18 (( trichloride. V O C13. 1.764, 20.~ I27.o 19 I.841, I40 5-) 20 (( ((.836, I7.0 5. 26.' 7. 21 (( 1.828, 24.0 760m. m. 22Carbon oxychloride. C 0 C12. 1.432, 0.0 t 892. 23 I.392, I8.0 6. 756.4mm. 24 Silicon ( Si2 0 C10. I36~-I39.~ -5 Phosphorus sulphochloride. P S C13. I26~-I27.~ 26 1 I26~-I27.0 27 (( I.63I, 22.0 1240~-125.~ 28Carbon ( C S Cl2. 1.46. 70.0 29Silicon1 ( Si3S2C18(?) 1.45, 15.0 a. I00.~ AUTHORITIES. 1 Weber. 12. 91. 11 (H. L. Buff. 29. 22 Emmerlig ad LeIgye1. 2 Michlllis. Z. F. C. 13. 460. 12 H. L. Buff. 29. Z. F. C. 13. 189. 3Thomson. P. T. 1827. 159. 13 - H. L. Buff. 29. 23 Eninerling and Lengyel. 4 Walter. A. C. Phys. (2). 14 I H. L. Buff. 29. Z. F. C. 13. 189. 66. 387. 15 I H. L. Buff. 29. 24 Friedel & Ladenburg. J. 5 Thorpe. 21. 226. 16 Wichelhaus. 20. 149. F. P. 107. 247. 6 Roscoe. Chem. News. 27 Roscoe. P. T. 1868. 1. 25 Aitscherlich. 25. 61. 18 Schafarik. J. F. P. 76.142. 26 Cahurus. 1. 364. 7 R. Miller. A. C. P. 122. 1. 19 (Roscoe. P. T. 1868. 1. 27 Baudriniont. 14. 115. 8 Cahours. J. F. P. 45. 129. 20 Roscoe. P. T. 1868. 1. 28 Kolbe. A. C. P. 45. 41. 9 Wurtz. 1. 365. 21 Roscoe. P. T. 1868. 1. 29 Pierre. J. F. P. 41. 342. 10 Meindelejeff. 13. 7. SPECTFIC GniA VITY T.ABLES. 39 6th. AMMONIO-CHLORIDES. Name. Formula. Specific Boiling Melting Gravity. Point. Point. Pupureo cobalt chloride. 10 N H3. Co2 C16. 1.802, 23.0 2 Luteo cobalt "c 12 N H3. Co2 C16. 1.70I6, 20.0 3Copper ammonio o 1st. Cu C12. 2 N H3. 2.194. 4 (( (( cc 2d. Cu CI2. 4 N H3. H. 0. 1.672. M5lercury " " Hg C12. N H3. 590.0 6 Dimercurosammonium chloride. (Hg2 N H2) Cl. 6.858. m.of 2 7 Dimercurammoniumn chloride. Hg2 N2 H4 C12. 5.700. 8 (?) Hg4 N2 C12. 2 H2 0. 7.176. m.of 2 IV. INoORGANIC BRONIIDES. 1st. SIMPLE BROMIDES. ANHYDROUS. Name. Formula. Specific BoilMelting Gravity. Boiing Point Point. 9 Hydrogen bromide. H Br. s.-87.~ 10 Sodiuml f Na Br. 2.952. 11 (1 3.079, 17.0 5. 12 3c0II 12 ( ( c(( 3.0o I I. 13 Potassium " K Br. 2.415. 14 (2.672. 15 ( c (c 2.690. m. of 6.'6Ammonium c N H Br. 2.379. 17 CC 2.266. I0.~ 18 Silver * Ag Br. 6.3534. 19 6.425. m. of 7. 20 5.8-6.02, Native. 21 Selenium o Se Br. 3.604, I 5. AUTHORITIES. 1 Gibbs & Genth. S. J. (2). I 6 Playfair and Joule. ) 14 Playfair and Joule. 11. 23. 234. 7 Playfair and Joule. 11. 15 Schr6der. 23. 2 Gibbs & Genth. S. J. (2). 8 Playfair and Joule. 16 Schr6der. 23. 23.319. 9 Faraday. P. T. 1845. 155. 17 BWdeker. 26. 3 Playfair and Joule. 11.'0 Schiff. 21. 18 Karsten. 3. 4 Playfair and Joule. 11. n Kremers. 10. 67. 19 Schr6der. 23. 5 Watts' Dictionary. 12 Tschernak. 27. 20 Berthier. See 23, or 27. 13 Karsten. 3. 3! Schneider. P. A. 128. 327. 40 SPECIFIC GIRAVITY T.1BLES. Name. Formula. Specific Melting Name. Formula. Gravity. Boiling Point. Point. 1Calcium bromide. Ca Br2. 3.32, II. 2 Strontium (( Sr Br2. 3.962. I2.~ 3 Barium ( Ba Br2. 4.23. 4 Lead Pb Br,2. 6.6302. 5(( ( 6.6I I, 175. 6 Cupro0US (( Cu Br. 4.72, I2.~ 7Zinc a Zn Br2. 3.643, IO.~ 8Cadmium (( d Br2. 4.712. 0 9 (1 (c 4.910. 14.'10 Iercurous (( Hg Br. 7.307. " Mereuric (( Hg Br2. 5.9202. 12 (( 222o-223.0 13 Boron tribromide. B Br3. 2.69. 1. 90?5. 31 Phosph11orus ((P Br3. 2.92489, o.0 1. I75~3. 760.2mm. 15 ~, 167.~ 16 Arsenic 0 As Br3. 220.0 200~-2 5.0 17 ( (( 3.66, I 5.~ 18 Antimony " Sb Br3. 270.0 94.0 19 ( ( (( 3.64I, 90.0 1. 275~4. 760 m. m. 90o. 20 Bismuth (( Bi Br3. 200.0 21 5.6041. (( (( (( 5.64I. 22 Carbon dibromide. C2 Br. 50o. 23 Carbon tetrabromide. C Br4. 91.0 24 Silicon (( Si Br. 1. 2.8128, o.~ I53.36. 762.3m.m. 25 (( ( I48~-I 50.~ s-I2~to-I 5.0 26 Titanium (( Ti Br. 2.6. 230.~0 39.0 27 Tin (( Sn Br4. 3.322, 39.0 1. 28s Aluminium bromide. A12 Br6. 2650-270.0 9o.0 29 (( 2.54. 260.0 93 0 AUTHORITIES. 1 Bo6deker. 26. 13 W6hler & Deville. 10. 94. 21 B6deker. 26. 2 B6deker. 26. 14 Pierre. 15, or 45. 22 Lennox. 14. 653. 3 Schiff. 21. 15 Baudrirnont. 23 Bolas and Groves. C. S. t. 4 Karsten. 3. 16Serullas. A. C. Phys. (2). (2). 8. 161. 5 Kremers. 5. 397. 38. 318. 24 Pierre. 15. 6 Bbdeker. 26. 17 Boideker. 26. 25 Serullas. A. C. Phys. (2). 7 Bideker. 26. 18 Serullas. A. C. Phys. (2). 48. 87. 8 1 B6deker & Giesecke. 26. 38. 318. 26 Duppa. 9. 365. 9 B6odeker & Giesecke. 26. 19 Kopp. 18. 27 Bbdeker. 26. 10 Karsten. 3. 20 Serullas. A. C. Phys. (2). 28 Weber. 10. 157. 1 Karsten. 3. 38. 318. 29 Deville & Troost. (?) 12. 26. 12 Oppenheim. Z. F. C. 13.155. SPECIFIC GIA VITY TABLES. 41 2d. HYDRATED, DOUBLE, OXY-, AND SULPHO-BROMIDES. Name. Formula. Specific Boiling Melting Gravity. Point. Point. 1 Sodium bromide. Na Br. 4 H2 0. 2.34. 2 Barium (( Ba Br2. 3 H2 0. 3.69o. Ammonium zinc bromide. 2N It4 Br. Zn Br2. 2.625, I3.0 4 Potassium platin bromide. 2 K Br. Pt Br4,. 4.68, I4.~ 5 Silicohydric bromide. Si3 H4 Br,,. a. 2.5. G Phosphorus oxybromide. P0 Br3. 2.822. S. or 1.(?) I95.0 450-46.0 7 (( ( (( I93.0 55.0 8 Vanadyl bromide. V 0 Br3. 2.9673,0o O. I30~-I36.~ (49 (C (( 2.9325, 145) 10 Phosphorus sulpho- 2.72. 2 I 5.0 39.0 bromide. P S Br3. 11 (4 2.85, I7.0 12 ((P S Br3. 12 0. 2.7937, I8.~ 35.0 V. INORGANIC IODIDES. 1st. SIMPLE ANHYDROUS IODIDES. Name. Formula. Specific Gravity. Boling Melting Point. Point. 13 Hydrogen iodide. H I. S.-5I.~ 4 Sodium Na I. 3.450. "5 Potassium ( K I. 3-078-3.1 04 16 ( 2.9084. 17 (4 ( ( 3.059. 18 (4 ( 3.056. 19 2.850. 20,(( ( 2.970. AUTHORITIES. 1 Playfair and Joule. 11. 8 Roscoe. 15 Boullay. 2. 2 Schiff. 21. 9 A. C. P. 8th. supp. vol. 95. 16 Karsten. 3. 3 B6deker. 26. 10 Baudrimont. (?) 17 Playfair and Joule. 11. 4 B6deker. 26. 11 Michaelis. A. C. P. 164.9. 18 Filhol. 12. 5 Buff and W6hler. 10.169. 12 Michaelis. A. C. P. 164.9. 19 Schiff. 21. 6 Ritter. 8.301. l3 Faraday. P. T. 1845. 155. 20 Buignet. 14.15. 7 Baudrimont. 14Filhol. 12. 4 42 SPECIFIC GRAVITY TABLES. Name. Formula. Boiling Melting Name. Formula.' Specific Gravity. Point. Point. Potassium iodide. K I. 3.08 1-3.o77. 2Ammonium NH N 1E4. 2.498, I I.~ 3 Silver " Ag I. 5.64-5.67. 4 ( (( (( 5.504. 5 ( (( CC 5.707. Iodyrite. 6 5.6I4. c7 (( ez(( 5.0262. c8 ( C, 5.500o 9 ( 5.366. Native. 13 0 o, C C( 5.35. c" 5.47. 65 0. 14 C 5.544. Cryst. 15 (C 5.687. After fusion. 16 5.807. o.0 Precip. 7 Strontium ( Sr T. 4.4I5, 10.0 18 Barium,, Ba 12. 4.917. 19 Lead (( Pb I,. 6. I I. 20 6.0212. 21 (C 6.384. 22 C6.07. 23 (c ( 6.207. 24 Cuprous iodide. Cu I. 4.410o. 25 Zinc (c Zn 12. 4.696, Io.~ 26 Cadmium Cd I2. 4.576, Io.~ 27 Mercurous (c Hg I. 7.75. 28 o (( (( 7.6445. 29 Mercuric o Hg I2 6.32. 30 ua ( 6.2oo9. 31 (C a tr 6.250. 32 (C 5.91. 33 (C C C( 6.27. AUTHORITIES. 1 Schr6der. 23. 13 H. St. Claire Deville. P. 22 Schiff. 21. 2 Bddeker. 26. A. 132.307. 23 Schlrider. 23. 3 Breithaupt. Iodvrite. 14 H. St. Claire Deville. P. 24 Schiff. 21. 4 )Domeyko. )Dana's Min- A. 132.307. 25 Bideker and Giesecke. 26. 4 Domeyko. f eralogy. 15 H. St. Claire Deville. P. 2B6Bodeker. 26. $ Damour. 7.870. A. 132.307. 27 Boullay. 2. 6 Boullay. 2. 16 H. St. Claire Deville. P. 28 Karsten. 3. 7Karsten. 3. A. 132.307. 29 Boullay. 2. s Filhol. 12. 17 Bodeker. 26. 30 Karsten. 3. J9 J. L. Smith. 7.870. 18 Filhol. 12. 31 Filhol. 12. 10 Schiff. 21.'9 Boullay. 2. 22 Schiff. 21. 11 Schroder. 23. 20 Karsten. 3. 33 Tschermak. 27. 12 Schrbder. 23. 21 Filhol. 12. SPECIFIC GRA VITY TABLES. 43 Specific Boiling Melting Gravity. Point. Point.' Mercuric iodide. Hg I2. 238.0 2 Phosphorus diiodide. P I. a I io. 3 ~( tri iodide. P I13. 55.0 4 Arsenic " As I3. 4.39, 13.~ 5 Antimony (Sb I3. 5.01, I0. 6 Bismuth ~ Bi I3. 5.652, I0.0 7 Silicon tetriodide. Si I4. 290.0 I20. 5. Titanium (( Ti 14. 360.~+ I 50.~ 9 Tin o Sn I4. 295.0 I46.~S. I42.0 lo(10 (( (( 4.696, I I.0 " Aluminum iodide. A12 I6. a. 185.0 12 (( (( (C 2.63. 350.~ 125.~ 2d. HYDRATED AND DOUBLE IODIDES. Specific Boiling Melting Gravity. Point. Point. 13 Ferrous iodide. Fe I2 4 H 0. 2.873, I2.0 14 Potassium platiniodide. 2 K I. Pt I. 5. I 54 2.0 15 (( (5-98-1 15 5. 198. 12. VI. CHLOROBROMIDES, CHLORIDES, AND BROMIDES. Specific Boiling Melting Gravity. Point. Point. 16 Carbon chlorobromide. C2 C14 Br2. 2.3, 2I.0 17 Silicon " Si C13 Br. 80.0 18s Phosphorus oxychlorobromide. P 0 C12 Br. 2.059, o. I35. -137.0 19 Mercury brorniodide. Hg I Br. 229.0 AUTHORITIES. 1 Oppenhein. Z. F. C. 13.155. 9 Personne. 15.172. 16 Malaguti. A. C. Phys. (3). 2 Corenwinder. 3.272. l0 Bodeker. 26. 16.24. 3 Corenwinder. 3.272. 11 Weber. 10.156. 17 Friedel & Ladenburg. 20. 4 Bodeker. 26. 12 Deville & Troost. (?) 12.26. 555. 5 Bodeker. 26. 13 Bodeker. 26. 18s Menschutkin. J. F. P. 98. 6 Bodeker. 26. 14 { Bodeker. 26. 485. 7 Friedel. J. F. P. 107.245. 15 Bbdeker. 26. 19 Oppenheim. Z. F. C. 13. 8 Hautefeuille. 20.207. 155. 44 SPECIFIC' GRAVITY TABLES. VII. OXIDES. 1st. SIMPLE OXIDES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 1 Water.* "2 0- 1.000, 4.0 100.0 0.0 2.(( 999889,+, 0.0 3 (4.988433+, 50.0 4(.958737+, Ioo.~0 5.999887, 0.0 6 (C (4.992247, 40.0'7 a( ~.999862, o.~ 8 0.99988, o.~ 1 9 a.95903, 9908. 10o (,. 93078, 130.8. 11 93123, I3I.~ 12 CC (4.93035, I311. 13 4.908 I 1,} 1 o(4.907835, 567.15.90715, 157.0 J 16 C, (.95892, IO00. 17 4(.999866, o.O' 18i (.98835, 50- 20 ( 9I9I2,10. 21 ((.92025,- 20.~ 22 0.9i84, m. of 2. 23 ( 23 } See II. 25 CC.9I75- m. of 22. 26 ( i.918. 27 (.922.) AUTHORITIES. 1 Standards of comparison. 10 F Mendelejeff. 57. 19 Brunner. P. A. 64.113. 2 Muncke. 36. 11' Mendelejeff. 57. 20 H20 at 00=1.0000. 3 HO0 at 3?78=l.0000. 12 Mendelejeff. 57. 21 See paper for other values. 4 For other temperatures see 13 Mendelejeff. 57. 22 Playfair and Joule. 11. paper. 14 Mendelejeff. 57. 23 Playfair and Joule. Cite 5 Stampfer. 37. See paper. 15 Mendelejeff. 57. determinations by eight 6 1HO2 at 3?75=l1.0000. 16 Buendelejeff. 5729. 20 at.. other experimenters. 3espretz. 39.. 16 Buff. 29. H i at0 ~ —.0000. 25 Dufour. P. M. (4). v. 20. 8 Mendelejeff. 57. 17 Rossetti. 67. 26 Duvernoy 59 9 Mendelejeff. 57. Rossetti.. 27 Duvernoy. 59. * In dealing with water and ice the compiler has not sought for completeness. Only the more prominent of a vast number of determinations are here given. SPECIFIC GRAVITY TABLES. 45 Name. Formula. SpecGravity.fic Boiling Point. Melting Gravity. Boiling Point. Point. 1Hydrogen peroxide. H2 02. 1.452. 2 Chlorine trioxide. 1. C12 03. I.3298. 8~ to 9.0 c3 ( -7. 1.387. o 745 m. m. 4 Iodine pentoxide. I2 05. 4.250. 5 (( (( c" 4.7987, 9.0 6 (( a c 4.487, 0o. 7 Sodium oxide. Na2 0. 2.8o5. s Potassium oxide. K2 0. 2.656. 9 Silver Ag2 O. 7.i43, 16~6. 10 (( (( (( 7.250. 11 (~ (( 8.2558. 12 cc (( 7.147. 3 peroxide. Ag2 03. 5.474. Impure. 14 Sulphurous acid. 1. S 02-. 1.42. -I0.~ 15 c (( i. (, 1.45. 16 ( (( 1. (( 105. 17; { 1. S-76.~ s18 ( 1. (( I.4911, —20~5. -80759.2m.m. 19 I (( 1.4609, —-9. 20 C c~ [, I1.4384, —2o8. 21 1 ( ~ I.43I8, —O725. 22 1( cc I.4252,+2~8. 23 1( (o I.4205, 4?51. 24 ( (( (( 1.4102, 8?27. 25 (( ( 1.4017, lI5. 26c l. ( 1.3887, I6~43. 27 (C c I1.3769, 20063. 28 (C c 1.3673, 2309I. 29,( (( (c 1.3587, 26?9. 30 (( (( c I.35I3, 29?57. 31 1. I.341 5, 32?96. 32 1 (( 1.3350, 35029. 33:(( (( (( 1.3258, 38?65. AUTHORITIES. 1 Thenard. Watts' Diction- 12Playfair and Joule. 11. 23 D'Andre6ff. 22. ary. 13 Mahla. 5.424. 24 D'Andreff. 22. 2f Brandau. 14 Faraday. P. T. 1823. 189. 25 D'Andreeff. 22. 3 t Z. F. C. 13.47. 15 Bussy. P. A. 1.237. 26 D'Andreeff. 22. 4Filhol. 12. 16 Bunsen. P. A. 46.97. 27 D'Andreeff. 22. 5 Kammerer. P. A. 138.401. 17 Faraday. P. T. 1845. 155. 281 D'Andreff. 22. 6Ditte. Z. F. C. 13.303. 18 Pierre. 1.63. 29 D'Andre6ff. 22. 7Karsten. 3. 19 (D'Andreff. 22. 30 D'Andreff. 22. s Karsten. 3. 20 1D'Andreff. 22. 31 D'Andreaff. 22. 9Herapath. 1. 211 D'Andreff. 22. 32 D'Andreff. 22. 0 Boullay. 3. 22 [D'Anidredff. 22. s3 L D'Andreff. 22. 11 Karsten. 3. 46 SPECIFIC GRA VITY TABLES. Boiling Melting Name. Formula. Specific Gravity. Boint. Point. 1Sulphuric acid. S 03. 1.9546, I3-0 s. 2 (( (( (1.975. S. 3 (I ( 1.97, 20.0 1. a 25.0 4 (( (( I.92II8. 5 es (( (( I.90915. 25.~ 6 (( (( I.908I4. s. 460-47.0 295. 7 (( (( ( I.8I95. 760 m.m. rs. 25~ c8 e (( o I.8o05. 47.0 9 o (( ((.8ioi. 1. 10 (( (( 46.0 n Tellurium dioxide. Te 02. 5.93, 20.~ 12 Calcium oxide. Ca 0. 3-I79. 13 (C(( ( 3.16105. 14 (C a( 3.1I80. 15 Strontium oxide. Sr 0. 3.932 I. 16 o (C 4.61 I. 17 Barium " Ba 0. 4.0. 18 ((, 4.7322. 19 CC C( (C 4.829-4.986. 20 C5.456. 21 peroxide. Ba 02. 4.958. 22 Lead suboxide. Pb2 0. 9-77223 o monoxide. Pb 0. 9.277. 1705. 24 (( (( (( 95. 25 (( (( (( 9.2092. 26 ( cc c 9.250. 27 CC 9.361. 28 9.3634, 4'0 29 8.o02. Cryst. 30 9.2-9.36. Native. 31 (( dioxide. Pb 02. 8.902. 16~5. 32 8-9332 (( ( 8.933. 33 ( ( 8.897-8.756. 4 (Miniu. Pb3 04. 8.94. AUTHORITIES. IMorveau. See 29. 12 Boullay. 2. 24 Boullay. See 23. 2 Baumgartner [26.411. 13 Karsten. 3. 25 Karsten. 3. 3 Bussy. A. C. Phys. (2). 14 Filhol. 12. 26 Playfair and Joule. 11. 4 H. L. Buff. 29. 15 Karsten. 3. 27 Fillhol. 12. 5 H. L.Buff. 29-. | P 16 Filhol. 12. 28 Playfair and Joule. 14. 6 H. L. Buff. 29- I; M 17 Fourcroy. 29 Grailich. 11.186. 71H. L.Buff. 2Q.0I d 18Karsten. 3. 30 Dana's Mineralogy. II. L. Buff. 29. I. 19 Playfair and Joule. 11. 31 Ilerapath. 1. 9 H. L. Buff. 29.). 20 Filhol. 12. 32 Karsten. 3. 0 Schultz Sellack. P. A. 139. 21 Playfair and Joule. 11. 33 Plavfair and Joule. 11. 480. 22 Playfair and Joule. 11. 34 MIuschenbroek. Watts' 1 Schafarik. 28. 23 Herapath. 1. Dictionary. SPECIFIC GRAVITY TABLES. 47 Name. Formula. Specific Gravity. Boiling Melting Point. Point. 1 Minium. Pb3 04. 9.096. I5.~ 2 9. I go. 3 (C 8.62. [The oxides of the iron and allied groups are arranged according to similarity of formula.] 4 Manganous oxide. Mn 0. 4.7264- 17-0 5 (c (( 5-38. 6 (( (( (( 5.09 I 7 Nickelous (( Ni 0. 5.597. 8(( ( 5.745. Furnace product. c9 ( (C (C 6.6o5. Cryst. o (( (c " 6.398. 1 ( 1c 6.66 I. 12 cc cc 6.8. Artif. cryst. 13 a( I c( 6.398. Bunsenite.'4 Cobaltous ( Co O. 5-597. 15 ( (( 5.75. After ignition. 16 Uranous U 0. IO. 5. 7 Cupric Cu 0. 6.401. I6~5. c18 (c c 6. I30. 19 CC (( (( 6.4304. 20 (c (C 5.90. 21 a 16.4I4. After ignition. 22 (( (( 6.322. 23 C ryst. furnace 23 ((c~ (( ~ (( 6.45 I product. 24 c c a 6.25. Melaconite. 2 ( (C (C 5.952. (( 26 Sesquioxides. R2 03. 27 Chromic oxide. Cr2 03. 5.21. Cryst. 28 (C 4.909. 9 ( (( (C 6.2. Cryst. AUTHORITIES. 1 Herapath. 1. 11 Ramnmelsberg. 2.282. 20 Playfair and Joule. 11. 2Boullay. 2. 12 Ebelmen. 4.16. 21 Playfair and Joule. 11. 3Karsten. 3. 13 Dana's Mineralogy. 22 Filhol. 12. 4 Herapath. 1. 14 f Playfair and Joule. 11. 23 Jenzsch. 12.214. 5 Playfair and Joule. 11. 15 l Playfair and Joule. 11. 24 Whitney. 2.728. 6 Rammelsberg. 18.878. Ia Ebelmen. J. F. P. 27.385. 25 Joy. 7 Playfair and Joule. 11. 17-erapath. 1. 27 Wihler. Watts' Dictions Genth. 1.444. 8 Boullay. 2. ary. 9 Genth. 1.444.'9 Karsten. 3. 28 Playfair and Joule. 11. 10 Bergemann. 11.683. 29 Schiff. 11.161. 48 SPECIFIC GRiAVITY TAIBLES. Boiling Melting Name. Formula. Specific Gravity. Boiling Melting Point. Point. 1 Chromic oxide. Cr203. 5.0I0. 2 Manganic Mn2 0. 4.82. Braunite. 3 ( o 4.6I9- Artificial. 5 (( o 4-568(( (( (( 4.325. Artificial.' 6 s (( 4.752. Braunite.) I Ferric s Fe2 03. 5.2 5 I. 8 5.26I. Natural. 9 ( ((1 I 1 19 o ( ( 5.121, I205. Natural. 1,,~0 4.959, I6~5. Precip. 11 (C 5.225. 12 (C 4.679. 13{( 5-135' Ignited. 14 5.241.' Native. (c,< o ( 5.283.J 15 ( 5.283. Native. 16 K (C 5.191. Native. 17 (, (( 5.214. From three 18 c 5.230. localities. 19 (( 5.I69. Precip. } 20 ( 0 5-037. Ignited.) 21 Nickelic Ni2 03. 4.8 I 4. ~~~~~~22 0 zf 4.846, I 6~5. 23 Cobaltic Co2 03. 5.322, I6~5. 24 ( 5.60. (2 (C (C 4.8I4. 26 Aluminic (A A2l 0,. 4I52, 4~ 27 ( c 3.944. ^28 (C ( 4.004. 9 3.53I. Ruby. 370 (C 3.562. Sapphire. 31 CC t 4.154. 32 0 zz zz 3.928. Artif. cryst. 33 C 4.022. Corundum. } 234 c (c 3.992. Above, after fusion.! AUTHORITIES. I'Sclr6der. 23. 125 Plavfair and Joule.. 24 Boullay. 2 Haidinger. See 23. 13 Playfair and Joule. 11. 23 Playfair and Joule. 11. 3 Playfair and Joule. 11. 14 Rammelsberg. 26 Rover and Dumas 4 Playfair and Joule. it. 15 Rammelsberg.c 27 ARohs and |u s 5 Rammelsberg. 18.878. 16 G. Rose. See 23. 28 1 Breithaupt. 6 Rammelsberg. 18.878. 17 G. Rose. 29 Brisson and Mohs. See 23. 18 G. Rose. 30 Muschenbroek. 8 BreitauptSee 23 19 H. Rose. P. A. 74.440. 31 ilhol. 12. 9 Kopp. See. 23. 20 H. Rose. P. A. 74.440. 32 Ebelmen. 4.14.,0 Herapath. 1. 21 Playfair and Joule. 11. 33 f Ch. St. C. Deville. See 23. 1 Boullay. 2. 22 Herapath. 1. 34 ( Ch. St. C. Deville. See 23. 23 Herapath.. 1. SPECIFIC GRAVITY TABLES. 49 Boiling Melting Name. Formula. Specific Gravity. Point. Point. 1 Aluminic oxide. A12 03. 3870-k Artificial. 2 3.899.J 3 3.750. Heated in a 4 (( ( ( 3.725.) wind furnace. ( Ign. in porcelain 5 a((~~ (( (( 3-999~- j rfurnace. 3899, I 5 7 (( (( (( 3.929. Corundum. 8 (( (( ( 3.974. 9 (( (1 (1 3.9998.)sapphire. o10 (1, 4.0001. ) 11 3.994. Ruby. m. of 9. 12 4.0067, I4? Powdered. 13 (( (( (( 3.989.) 13.5. 14 (( (( (( 4.oo8. Powder after ig(( 4.0 o.) nition. 15 Three to four oxides. IR 04. G 0Mangano-manganic oxide. Mn3 04. 4.722. Hausmannite. 17 4.746.) Artif 18 (( (( t 4.653.- At 19 ((. (( ( 4.325. Artificial. 20 (( (( (( 4.718. Artificial.) 21 4.856. Native. 22 Ferroso-ferric oxide. Fe3 04. 5.094. 23 4.960. 24 4.900-5.200. 25 5 3 6 23 (( (( c( 5.300, 16.~5. 26 5.400. 27 ~ (C 5.480.) 28 ( 5.i68.) Cryst. 29 (( (( 5.1 80. Magnetite. 30 (( ( (( 5-45331 5.12, o.0 Native. 32 ( I85. } Native. 33 (( (( (( 548. From three 34 (( (( | (( | 5.I06. localities. AUTHORITIES. 1 H. Rose. P. A. 74.429. 12 Schaffgotscl. 24 See 11 3Schlaffgotschl. P. A.74 2 (H. Rose. P. A. 74.429. 13 Schaffgotsch. 429. 25 Herapath. 1. 3 (H. Rose. 14 Schaffgotsch. 26 { Boullav. 2. 4 H. Rose. 16 Dana's Mineralogy. 27 T loullay. 2. 5 H. Rose. 17 I Playfair and Joule. 11. 28 { Kenngott; see Dana's 6 (Schaffgotsch. P. A. 74. 18) Playfair and Joule. 11. 29 Mlileralogy. 7 Schaffgotsch. 429. 19 Playfair and Joule. 14. 30 Playfair and Joule. 11. 8 I Schaffgotsch. 20 5 Raminelsberg. 18.878. 31 Kopp. See 23. 9 ) Schaffgotselh. 21 Ramnmelsberg. 18.878. 32 (Rammelsberg. See 23. 1i Schaffgotsch. 22 1\ohs. 33 Ranmelsberg. See 23. L ISchaffgotsch. J 23 Gerolt. See 11 34 Rallmelsberg. See -23. 50 SPECIFIC GRA VITY TABLES. Name. Formula. Specific Gravity. Boiling Metin'Cobaltoso-cobaltic oxide. Co3 04. 5.8332 (( (( 6.296. 3 Uranoso-uranic ( U3 04. 7.1932. ( (( (( ( 7.3 I. 5 Trioxides. R1 o7. 6 Chromium trioxide. Cr 03- 2.676. m. of 2. (71( (C (( 2.737, I4.~ Cryst. 8 2.629, I4.0 After fusion. 9 ( (C 5 2.8I9, 20.o o0 Molybdenum Mo 03. 3.46. ii (C (( 3.49. 12 4.49-4.50. Native. 13 (C 4.39. 21.~ mn.of2Cryst. 14 Tungsten ( W 03. 6.12. 15 ~~ (( (( (( ~5.274, 1675. 16 ( ( 7. I 396. 17 (( (( N " 6. 302. Cryst. 18 C 6.384. )ry 19 (( 7.I6. Amorphous.t 20 ( 7.232, I7.0 Cryst. j [Miscellaneous oxides of thle Fe. Pt. Mo. Zn. groups.J 21 Manganese dioxide. Mn 0 4.81. Pyrolusite. 22 5.026. 23 4.838. 23 ( (C (( 4.880. fl~oianite.8 25 (O 4.826. Polianite. 26 Cuprous oside. Cu2 0. 5.75. 27 (( (( a (( ( C( 6.052. 29 5.751. 30 (( (.746. 31 5.992. Cuprite. AUTHORITIES. I Ranmelsberg. 2.282. 13 Schafarik. 28. 23 Breithaupt}. 2 Rammelsberg. 2.282. 14 De Luyart. See 11. 24 Breithaupt. A ineraliogy. 3 Karsten. 3. 15 Herapath. 1. 25 Pisani. ) 4 Ebelmen. J. F. P. 27.385. 16 Karsten. 3 26 Leroyer & Dumas. See It. 6 Playfair and Joule. 11. 17 Nordenskiild. 14.214. 27 Herapath. 1. 7 Ehlers 26. 181 Nordenskidld. 14.214. 28 Herapath. 1. 8 Ehlers. 26. 19 Zettnow. 20.216. 29 Karsten. 3. 9Sclhafarik. 28. 20; Zettnow. 20.216. 30 Plavfair and Joule. 1. 10 Thonlson. 21 Turner. See 11. 31 Haidinger. Dalla's Min11 Berzelius. See 11. ralogy. 22 Ramlllnelsberg. 18.878. eralogy. 12 TWeisbach. Dana's Miner SPECIFIC GRAVITY TABLES. 51 Grviy FBoiling Melting Nam e. Formula. Specific Gravity. Point. Point.' Ruthenium dioxide. Ru 02. 7.2. 2 Ruthenium tetroxide. Ru O0. a. Ioo.0 58.0 M Molybdenum dioxide. Mo 02- 5.67. 4Tungsten (( 2- I 2. I 9. 5 Zinc oxide. Zn 0. 5.432. 6 (C I 5.600. 7C (( (o ( 5-7344. 8 (( 5.6o67. 9( (( o( 5.6570.) 10o (C 5.5298. Cryst. 11 5.6 I 2. 12' ( 5.684. Zincite. 13 Cadmium oxide. Cd 0. 8.183. I6^5. 14 CC 6.9502. 15 8. i. 15 (( (( (( 8. I I I. 1G Magnesium oxide. Ag 0. 3.674. Periclase. 17 CC cc (( 3-75018 (( (( (( 3.200. 19 3.644.) 20 ( (3.650 21 (C 3.636. Artif. cryst. 22 Mercurous c Hg2 0. Io.69. 16~5. 23 8.9503. 24 Mercuric ( Hg 0.o I.074. I7?5.) 25, C I I.o85. I8~3.) 26 (( Ic, I I.O. 27 I cI 11. I. 909. 28 I (( I I.29. 29 (C I 1.344. 0so 11.136. [Mliscellaneous oxides of unclassified metals.] 31 Glucinum oxide. GI 0. 2.967. 132 (( (( (( 3.02-3.06. Cryst. AUTHORITIES. 1 Dl)eville & Debray. 12.236. 11 Filhol. 12. 22 Herapath. 1. 2 Claus. 12.262. 12 W. P. Blake. 13.752. 23 Karsten. 3. 3 Bucholz. Nich. Journ. 20. 13 Herapath. 1. 24 f Herapath. 1. 121. 14 Karsten. 3. 25 t Herapath. 1. 4 Karsten. 3. l5 Werther. See 23. 26 Boullay. 2. 5 Mohs. See 11. 16 Damour. See 23. 27 Karsten. 3. 6 Boullay. 2..17 Scacehi. J 28 Leroyer & Dumas. See 11. 7 Karsten. 3. 18 Karsten. 3. 29 Playfair and Joule. 11. s Brooks. P. A. 74.439. 19 Rose. P. A. 74.437. 30Playfair and Joule. 14. 9 { Brooks. P. A. 74.439. 20 Rose. P. A. 74.437. 31 Ekeberg. P.M. (1). 14.346. 10W. & T. J. Herapath. C. S. 21 Ebelmen. 4.15. 32 Ebelmen. 4.15. J. 1.42. 52 SPECIFIC GRA VIT'Y TABLES. Name. Formula. Boiling Melting Name.: Formula. Specific Gravity. Point. Meting Glucinum oxide. G1 0. 3.09-3.083. Powder. 2 I 3.o96, 12.~ Precip. ( 3.027, io gnited in porcelain furnace. (4 1 (C (C 3.02I, 9.0 Cryst. 5 Yttrium (( Y 0. 4.842. 6 Ceric C Ce2 0,. 5.6059. 7 (( (C (( 6.oo. 8 Ceroso-diceric oxide. Ce5 07. 5.769. 9 Ceroso-ceric oxide. Ce3 04. 6.93-6.94. I5.05 10o (( (( (C 7.09, I4~5. Cryst. 1 Lanthanum (( La 0. 5.94. 12 ( 5.296, I6.0 4- tr. B. O0.'3 Didymium Di 0. 6.64. 14 5.825, 14.' + tr. B, 03.'5 Thorium Th 0. 9.402. 16 n (( (C 9.2I. 17( (( g9.077-9.200. [Nitrogen group.] 18 Nitrous oxide. 1. N2 0.9756, -5. 19 N71. -.9370, o.0 20 (( It 1. ~.9I77,+ 5.0 21 (( I..8964, IO.0 22 (( 0 1. ((.8704, 15.0 23 1, o l. (.8365, 20.~ 24 Hyponitric acid. 1. N 02. 1.45I. 28? 760 m.m 25. 1.42. 28.0 26 Nitrogen pentoxide. N2 0 450o50.0 29o-30.0 27 Boron trioxide. B2 03. I75. 28 (( 1.83. 29 C 1I.83. 30 Phosphorus pentoxide. P2 05. 2.387. "1 Vanadium oxide. V2 02. 3.64, 20.0 Supposed metal. 32 t(( rioxide. V2 03. 4.72, 16.0 m. of 3. AUTHORITIES. 1 rH. Rose. P. A. 74.433. 13 Hermann. 14.195. 24Dulong. Schweig. J. 18. 2 H. Rose. P. A. 74.433. 14 Nordenski51d. 14.197. 177. 3] H. Rose. P. A. 74.433. 15 Berzelius. P. A. 16.385. 25 Mitscherlich. Schweig. J. 4 H. Rose. P. A. 74.433. 16 Nordenski6ld & Chydenius 63.109. 5 Ekeberg. P. M. 1. 14. 346. 13.134. 26 Deville. 2.257. 6 Karsten. 3. 17 Chydenius. 16.194. 27 Breithaupt. 7 Hermann. 17.193. 18 D'Andre6ff. 22. 28 Dav. See 11. 8 Hernmann. 17.193. 19 D'Andreff. 22. 29 Berzelius. 9 f Nordenskiild. 14.184. 20 D'Andreff 22. 30 Brisson. See 11. ~10 Nordenski6ld. 14.184. 211 D'Andreff. 22. 31 Schafarik. J. F. P. 76.142.'n Hermann. 14.192. 22 D'Andreeff. 22. 32 Schafarik. 28. 12 Nordenski6ld. 14.197. 23 D'Andreeff. 22. SPECIFIC GRA VITY TABLES. 53 Boiling Melting Name. Formula. Specific Gravity. Bointg Metint 1 Vanadium pentoxide. V2 05. 3.472 20. 2 (( (( 3.510'O 3 Arsenic trioxide. As2 03. 3.698. 4 3(1 (( 3.69o -3.710. 65 zz ( (C 3.695. Octahedral. 6 o 3.7385. Amorphous. 7 0 (c 3.729, I772. 8 ( 3.7202. 9 ( (( (C 3.7026.) 10 3.884. 11,, 3.85. Native, prismatic. (( pentoxide. As2 05. 3.7342. 13 ( 4.023.) 14 (( (( 3.9851$ 15(~ (C 4.250. 6G Antimony trioxide. Sb2 03. 5.57. 17 5.778. is 6.6952. 8 (( (( (( 192 5 I.251. 20 v C (( 5.I I. Octahedral. 21 Co (1 3.72. Prismatic. f 22 Senarmontite. (c 5.22-5.30. 22 Valentinite. ec 5.566. Cryst. 2= Antimony tetroxide. Sb2 04. 4.074. 22 (( (( (( 4.084. Cervantite. 26 pentoxide. Sb2 0O. 6.525. 27 (( (( ((,37 27 CC 3.779. 28 Bismluth trioxide. Bi2 032 6.7608, I65. 29 C 8.2II, I8~3. After igni30 C 8-.45. 31 ( (( 31 C 8.1735. 32 v 8.079. AUTHORITIES. Schafarik. J. F. P. 76.142. 12Karsten. 3. 23 Dana's Mineralogy. 2 { Schafarik. J. F. P. 76.142. 13 JPlayfair andJoule. 11. 24Playfair and Joule. 1111. 3 Le Royer & Dumas. See 11. 14 X Playfair and Joule. 11. 25 Dana's Mineralogy. 4Leonhard. See 11. 15 Filhol. 12. 26 Boullay. 2. 5 f Guibourt. 16 Mohs. 27 Playfair and Joule. 11. 6 Guibourt. 17 Boullay. 2. 28 Herapath. 1. 7 Herapath. 1. 18Karsten. 3. 29 Herapath. 1. 8 { Karsten. 3. 19 Playfair and Joule. 11. 30 Le Royer and Dumas. 9 Karsten. 3..20 Terreil. J. F. P. 98.154. 31 Karsten. 3. 10 Filhol. 12. 21 Terreil. J. F. P. 98.154. 32 Playfair and Joule. 11 " Claudet. 21.230. 22 Dana's Mineralogy. 54 SPECIFIC GRA VITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. [Carbon group.] 1Carbon dioxide. 1. C 02..9 -20. 0 2 L ((.83. 3.~0 -73.0 3 C 1..6. +30.0 4 (( (. i- |56?5 to-58? 5 (( 1. 9952, o. 6 CC (( I..9710o, - 5.0 7 (( (C 1. ((.947 I, O.0 8 (( (( 1..9222, + 5.0 9 (( (( 1..8948, IO.~ 10, 1..8635, 15. 11 ( < 1. ((.8267, 20.0 ~~~12..783I, 25.~ 13 Silicon ( Quartz. Si 02. 2.653. Cryst. 14 (C C CC (C 2.6354.l Extremes of ~~~15 2.63~ -~~~ 54. ~~ eleven 15 (( ( (( (( 2.6541.) determinations. s16 C C( 2.653, I3.~ m. of 5. 171 C ( C (( (( 2.653, 130~ Pulv. sand2.653, 130 ostone. 18 C( CC (4 2.656. Cryst. 19 CC CC C(( C( 2.22. After fusion. 22 (( (( (( 2.326. I i6. 25.(( (C 4244. 28 (( (C 4.26. Artificial. 292 (( (( 4.283. 30 4( < ( o.3.-331 ( 5(( ( 2.5 18 32 (? ( 4.8. 33 (( (( ( 3.9326. Artif. powder. AUTHORITIES. Thilorier. A. C. Phys. (2). D'Andreff. 22. 22( v. Rath. 21.1001( 60.427. 12 ID'Andredff. 22. 23 v. Rath. 21.1001. D'Andref. 22. e minerals men. 12.1 4.3 (( 2 1 1 heerm t f Thilorier. A. C. Phys. (2). 24o D'Ansrea. 22.h |da D'AndrefP. 22. 21 V. Rath. 21.1001. rsten. 3. determinations for opal[D'Andreiff. 22. in29 Ebelmen. 1214. 6 D'Andretff. 22. 8s Ch. St. Claire Deville. 8.14. "0 Hautefeuille. 16.212.'I r D'Andre~f 22. 19 Ch. St. Claire Deville. 8.14. 31 Miffer. 5.847. 6 j D'AndreffE 22. 20 Schaffgotsch. P. A. 68.147. 32 Klaproth. D'Andreff. 22. 211v. Rath. 21.1001. 33 Karsten. 3. 10 [ DAndre6ff. 22. SPECIFIC GRA VI'Y TABLES. 55 Name. Formula. Specific Gravity. Boiling Meltin Point. Point.'Titanium dioxide. (???) Ti 0. 4.253.) Powder. 2 (( (( (( (( 4255. iIgnited. 3 (C ( (' 4.128. 4 (( *( Brookite. (, 4.I. Artificial. 5 (C (C (C 4.12 8.1 67 (( 4. I. I31 s8 ( z(C ( C( 4.166. 9 ( ( ( ( 3.8I. From Ural. 10 ( ( 4.2 I 6. (( 11 o 3.952. Arkanosite. 12 (( z ( 0 3.892.1 13 ( ( 3-949.f 14 (( (( (( 4.22. 156 (C ( (( 4.20. 16 (( (( (( 4.03-4.o83. Arkansite. 17 ( ( 4.085. 18 ((,( Anatase. 3.890.) 19 (( (( ( (( 3.912.f 2 { (( (( 22 (( (( (( 3.826. 23 3.82. 24 ( ( ( 4.06. From Brazil. 25 (( 3.7-3.9. Artificial. 26 Tin monoxide. Sn 0. 6.666. i 65. 27 dioxide. Sn 02. 6.72. 28(( (( ( 6.96. ~~29~~ " 4.933. ri7?8. (( (( (( 30 6.639. i6~5. 31( (( 6.90. 32 cc ( 3 (( 6.892-7. 80. 33 6c (( cc - 6.95-6.96. 34 6.831. 0o. AUTHORITIES. 1 { Rose. See 23. 12 f Rammelsberg. 2.730. 24 Damour. 10.661. 2 Rose. See 23. 13 Rammelsberg. 2.730. 25 IIautefeuille. 17.215. 3 Playfair and Joule. 11. 14 Frodmann. 3.704. 26 Herapath. 1. 4 Eautefeuille. 17.214. 15 Beck. 3.704. 27 Daubree. See 23. 5 H. Rose. See 23. 16 Damour. 2.731 28 Mohs. 6 H. Rose. See 23. 17 Whitney. 29' Herapath. 1. 7 H. Rose. See 23. 18 j H. Rose. 30 Herapath. 1. 8 H. Rose. See 23.'19 H. Rose. 31 Boullay. 2. 9 Romanowsky. 2.729. 20 Vauquelin. 32 Breithaupt. 10 Romanowsky. 3.704. 21 Breithaupt. See 23. 33 Neumann. See 23 1 Breithaupt. 2.730. 22 Mohs. 34 Kopp. 23 V. Kobell. J 56 SPECIFIC GRA VITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Nam. Specific Gravity. Point. Point. Tin dioxide. Sn 0, 6.849-6.978. 2a 6.7I22, 4.0 3 O( zt (t 6.753. Fr. Wicklow. ~r4 < 9. 6.862. Fr. Mexico. 5 (( (, Bolivia. (I 6.8432, 5. olorless. 6 (6 ( (( 6.8439. 7, (( (( 7.021, 15~5. Black. A R( 6.704, I5~5. Yellow. 9 Zireonium dioxide. Zr 0.. 4 35- Amorphous. o0 (< (< 0 to 4.9g. 11 ( 5.49. 12 (( 4.3. 13 9 s 5.42. 14 9 o 5.5. 15 4-9. 16 9 (( 5.742, I 5.) 17 5.7 IO, I5.0~ s18 of( 0 5.624, I5.0) [Miscellaneous.] 19 Niobium pentoxide. Nb2 05. 4. 56. ) Extremes of several 20 (( ( 5.26.) determinations. 21 ( 6.I40. From fusion 22, ((.t 6. I46. with K2 S2 07 23 6.48. Above, ignited. 24. c 5.83. More strongly heated. J 25, 5.90. 26 cc cc O (( 5.98- I From 27zl~~ ~g~~ (( z 5.706. 7 I chloride. 28 4 (1 6.239 J 9 29 6. I-6.4. Ignited. so ( 6.725, 81 (( u 5.79. Morestronglyheated. 1S ( 2,((2 5L 55 I-5. 52. AUTHORITIES. 1 H. Rose. See 23. 13 Knop. A. C. P. 159. 36. 21 r H. Rose. 12. 158. 2 Playfair and Joule. 14. 4 Sj6gren. 6. 349. 22 H. Rose. 12. 158. 3 Mallet. 3. 705. 15 Berlin. 6. 350. 23 H. Rose. 12. 158. 4 Bergemann. 10. 661. 16 Nordenski6ld. P. A. 114. 24 H. Rose. 12. 158. 3 5 forbes. P.M. (4). 30. 139. j 626. 25 H. Rose. 12. 158. ^ 6 Forbes. P. M. (4). 30. 139. 17 Nordenskidld. P. A. 114. 26t H. Rose. 12.158..- 7 Forbes. P.M. (4). 30. 139. 626. 27 H. Rose. 12. 158. 8 Forbes. P. M. (4). 30. 139. 18 Nordenskiold. P. A. 114. 28 H. Rose. 12. 158.. 9 Watts' Dictionary. 626. 29 H. Rose. 12. 158. 10 Watts' Dictionary. 19 H. Rose. 1. 405. 30 H. Rose. 12. 158. 11 R. Hermann. 19.191. 20 H. Rose. 1.405. 31 H. Rose. 12. 158. 2 Klaproth. See 11. 32 [ H. Rose. 12. 158. SPECIFIC GRA VITY TABLES. 57 Name. Formula. Specific Gravity. Bilg eltin Point. Point. I Niobium pentoxide. Nb2 0s. 4.56. Extremes of I2 Uc o 6.54.f several. 3 o s 5'20. 14.4 cc " 5.48. Cryst. c5 < cc c( 4.37-4-46.- Prepared by 6 (( (u a 4.5I-4-53.5 two methods. 7 (( (4 7 C (C (1 4.31. (C8~ (C (C ~ ~5.00. 9 Tantalum o Ta. 05. 7.03.)- Extremes of several (15(0 (( 8.26.j determinations. 11 (( 7.055.) From fusion ~12 o 7.065. with K2 S, 07. 13 ( ( 7.986. Heated more strongly. 7.0287.280 {From r4 Oc ( o( I7.028-7.280. { chloride. 15 (( (( 7.284. Crystalline fr. Ta C15. 16 (( c 7.994. Strongly ignited. 17,( ( 7.652. More strongly heated. 18 (c (( ( 8.257. Porcelain furnace. J 19 (( 7.00. 20 ci 0 7.3 5. Ign. precip. from Ta Cl5. 21 ar cc 8.oi. From N H, Salt. 22 ((G 7.6o.} From K Salt. 22 a o 7.64.) 2d. DOUBLE OXIDES. Name. Formula. Specific Gravity. Boilntg Melting 24 Sodium uranium oxide. Na, 0. 3 U2 03. 6.912. 25 Zinc iron oxide. Zn O. Fe2 03. 5.I32. Artif. cryst. 26 Magnesium iron oxide. Mg O Fe3, 03. 4.568. Magnesio27 a (( 4.654.) ferrite. AUTHORITIES. { H. Rose. 13. 148.'OlH. Rose. 1. 404. 19 Hermann. 18. 209. 2 H. Rose. 13. 148. " fH. Rose. 10. 178. I 20Deville & Troost. 20. 207. 3 J Nordenski6ld. 14. 209. 12 TH. Rose. 10. 178. w 21 Marignac. J. F. P. 99. 33. 4 Nordenskiild. 14. 209. 13 H. Rose. 10. 178. a.. 22 Marignac. J. F. P. 99. 33. 5 ( Marignac. 18198. H.198Rose. 10. 18. 23 Marignac. J. F. P. 99. 33. 6 Marignac. 18. 198. 15 H. Rose. 10. 178. I.2 24 Drenkmann. 14. 257. 7 Knop. A. C. P. 159. 36. 16 H. Rose. 10. 178. *2 * 25 Ebelmen. 4. 13. H8 ermann. 18. 209. 17 H. Rose. 10.178. 26 Dana's Mineralogy. H9. Rose. 1.404. 18s H. Rose. 10. 178. J g 27 Dana's Mineralogy. 27 Dana's Mlineralogy. 58 SPECIFIC GRAVITY TA BLES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. MI anganese chromium oxide. Mn 0. Cr2 0,. 4.87. Artif. cryst. 2 Iron chromium (( Fe 0. Cr2 03. 4.32. Chromite. 3.t r ((8 4.498. Chromite,fr.Styria 4 (( (" 1 4.568. Chromite, fr. Pa. 5 Zinc a Zn 0. Cr2 023 5.309. Artif. cryst. G Iron aluminum ". Fe 0. A12 03-. 3.9I-3.95. Hercynite. 7 Zinc ( O A Zn 0. A12 03. 4.580. Cryst. 8 (( 4.I-4.6. Automdlite. 10 589. Gahnite. a10 ( Co (1e 4.317.) 11 "C <( 4.89. Gahnite from 12 (( <( (( o 4.9 I. Franklin. 3 Magnesium aluminum oxide. Mg 0. Al2 0s. 3.452. Artif. cryst. 14 0 (C 3.48-3-52. Spinel. 15 ( 3.523.~ ~ 16 CC (C 3.575. Red spinel. 7 Glucinum aluminum oxide. G1 0. Al2 03. 3.759. Artif. cryst. 8195 (C ~ 3-597. ) Chrysoberyl. 19 (C oC CC(C 3.689. From three 20 o (C 3.734. localities. 21 C ~ 3.835. Chrysoberyl. 22 ( u (C (C CC 3.644. Alexandrite. AUTHORITIES. I Ebelmen. 4. 13. 8 Dana's Mineralogy. 16 Dana's Mineralogy. 2Thomson. Dana's Miner- 9 J G. Rose. See 23. 17 Ebelmen. 4. 13. alogy. O G. Rose. See 23. 18 { Rose. Dana'sMineralogy. 3 (Dana's Mineralogy. 11 Brush. Sill. J. (3). 1. 28. 19 Rose. Dana'sMineralogy. 4 Dana's Mineralogy. 12 Brush. Sill. J. (3). 1. 28. 20 Rose. Dana'sMineralogy. 5 Ebelmen. 4. 13. 13 Ebelamen. 4.12. 21 Kokscharof. 14. 976. 6 Zippe. See 23. 14 Breithaupt. See 23. 22 Kokscharof. 15. 715..7Ebelmen. 4. 13. 15 Haidinger. Dana's Min. SPECIFIIC GRA VITY TABLES. 59 VIII. SULPHIDES. 1st. SIMPLE SULPHIDES. Name. Formula. Specific Gravity. Boiling Melting ~~Name. Formula. Specific GraPoint. Point. 1 Hydrogen sulphide. H2 S. s.-855. 2 Sodium (Na2 S. 2.471. 3 Potassium K2 S. 2. I 30. 4 Silver ( Ag2 S. 6.8501. Artificial. 5 c c 7.3I-7.36. Acanthite. 6 (((( 7. I64-7.236. ( c7 ( (( (( 7.I88-7.326. ( 8 (( cc 7.269-7.3I7. Argentite 9 C T h cc 7.02. Daleminzite. 10Thallium, T12 S. 8.oo. 11 Oldhamite CaS.Impure. 2.58. 12 Lead monosulphide. Pb S. 7.220. 13 (( (( 7.40-7.60. 14 co (( 7.587. 15 CC c 7.568. 16 ( (c 7.5052. Artificial. 17 (( 7539 18 (( c (( 6.9238.4.0 Powdered. 19 (( (( 7.5I. From Przibram. 20 sesquisulphide. Pb2 SI. 6.335. 21 Chromium ~ Cr2 S3. 4.092. 22'(( (( (( 2.79, Io.' Two pre23 (( c( (( 3.77, I9.~. parations. 24 Manganese monosulphide. MIn S. 3.95-4.oI. Native. 25 (( (( (( 4.014. 26 (( (( (( 4.036. From Mexico. 27 o disulphide. Mn S2. 3.463. Hauerite. 28 Iron hemisulphide. Fe2 S. 5.8o. AUTHORITIES. 1 Faraday. P. T. 1845. 155. n1 Maskelyne. 20 Playfair and Joule. 11. 2 Filhol. 12. 12 Muschenbroek. 21 Playfair and Joule. 11. Filhol. 12. 13 Leonhard. 22 Schafarik. 28. 4 Karsten. 3. 14 Brisson. See 11. 23 Schafarik. 28. 5 Kenngott. 8. 908.'5 Mohs. J 24 Leonhard. ) 6 (Dauber. 13. 748. From two 16 Karsten. 3. 25 Mohs. See 11. 7 Dauber. 13. 748. localities. 17 Breithaupt. J. F. P. 11. 151. 26 Bergemann. See 23. s Dauber. 13. 748. 18 Playfair and Joule. 14. 27 v Hauer. 1. 1157. 9Breithaupt. 15. 709. 19 Tschermak. 27. 28'layfair and Joule. 11. 10 Lamy. 15. 185. 60 SPECIFIC GRAVITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Point. Point.'Iron monosulphide. Fe S. 5.035. m. of 2. Artif. 2 (, (( [( 4.787. Troilite. (3 ( es (" 4-75. ( 4 ( ( 4.79. Artificial. b " 4.8I7. Troilite. 6 disulphide. Fe S2. 5.000-5.028. Pyrite ~r7 (( ((( 5 1I 85.'Maximum of 52 det. 8 ( 4.678. Marcasite. 9 (( tl ( 4.847.J 10 ( (" 4.93. Pyrite. 11 sesquisulphide. Fe2 S3. 4.246. 12 (C ~ 4.4 I. 13Complex sulphide of iron. Fe8 S9. 4.494. 14 Pyrrhotite. Fe7 S8. 4.584. Fr. Kongsberg. is (C 4.546, o Bodenmais. 16 4.580, o( Harzburg.o r i,n 17 a( 4.564, a Mexico. 18 CC 4.640, ( onnecticut.J 19 Nickel hemisulphide. Ni2 S. 6.o5. 20 rnmonosulphide. Ni S. 4.601. Millerite. 21, ( 5.65., 22 Cobalt a, Co S. 5.45. Syepoorite. 23 disulphide. Co S2-. 4.269. 24 ( sesquisulphide. Co2 S3. 4.8. 25 Copper hemisulphide. Cu2 S. 5.695. 26 5.7022. Chalcocite. 27 CC 5.792. 17.7. 28 C, Co 5-977529 ( 5.7. 30 ( nmonosulphide. Cu S. 3.8. 31 CC 4. I634. 32 C( 4.636. Covellite. 33 Palladium hemisulphide Pd2 S. 7-303, I5.0 AUTHORITIES. 1 Playfair and Joule. 11. 12 Rammelsberg. 15. 262. 23 Playfair and Joule. 11. 2 Rammelsberg. 1. 1306. 13Rammelsberg. 15. 195. 24 Hoffmann's Tables. 3Smith. 8. 1025. 14Kenngott. Wien Ak. 9.575. 25 Mohs. See 11. 4Rammelsberg. 15. 263. 15 Schaffgotsch. 26Thomson. Dana's MinRammelsberg. 17. 904. 16 Rammelsberg. - I eralogy. 6 Kenngott. 6. 780. [289. 17 Rammelsberg. a 27 Ilerapath. 1. 7 Zepharovich. Wien Ak. 12. 18 Rammelsberg.J P 28 Karsten. 3. 8 (Dana's Mineralogy. 19 Playfair and Joule. 11. 29 Kopp. 16. 5. 9 Dana's Mineralogy. 20 Kenngott. Wien Ak. 9. 575. 30 Walchner. See 11. 30 Forbes. Dana's Miner- 21 Rammelsberg. Dana's 31 Karsten. 3. alogy. Mineralogy. 32 Zepharovich. 7. 810. 21 Playfair and Joule. 11. 22 Dana's Mineralogy. 33 Schneider. P. A. 141. 532. SPECIFIC GRAVITY T'.BLES. 61 Name. Formula. Specific Gravity. Boiling Melting Point. Point.'Platinum monosulphide Pt S. 8.847, 16025. 2 (( disulphide. Pt S2 7.224, 8~75, 3 c,, (( 5.27. 4 sesquisulphide. Pt2 S,. 5.52.'Molybdenum disulphide Mo S2 4.59. 6 4.44-4.8. Molybdenite 7 Tungsten disulphide. W2 S2 6.26, 20.0 8Zinc sulphide. Zn S. 3.9235. 9 (( (( (( 4.063. White Blende. 10 4.07. Blende. 11 (c ( 4.05. 12 (c 3.98. Wurtzite. 13 Cadmium sulphide. Cd S. 4.9o. Greenockite. 14 (( 4.80. (c 15 c (C 4.605. 16 " 4.5. Artif. Cryst. I~r17 (C CC 4.5. Artificial. 18 Mercury " Hg S. 8.998. Cinnabar. 19CCC 8.124. o (( (( (( 20 8.o6o2. 21 " 8.ogo. Cinnabar. 22 7.701. Amorphous. 23 (( (( 7.748. Natural. 24 7.552.Amorph.Artif. J 25 Nitrogen (( N S. 2. I 66, I 5.0 26 Phosphorus monosulphide. P S. i.8. 27 (( hexsulphide. P S6. 2.02. 28 Diphosphorus trisulphide. P2 S3. 290.~ 29 Tetraphosphorus (( P4 S3. I42.0 30 Vanadium sulphide. V2 S4. 4.70, 2.I0 31 Arsenic disulphide. As2 S2. 3 5444' 32 CC C. 3.4-3.6. Realgar. AUTHORITIES. 1 Bttger. J. F. P. 3. 267. 12 Dana's Mineralogy. 22 (Moore. J. F. P. (2). 2. 319. 2 B6ttger. J. F. P. 3. 267. 13 Breithaupt. See 11. 23 Moore. J. F. P. (2). 2. 319. 3 Schneider. P. A. 138. 604. 14Brooke. P. A. 51.274. 24 (Moore. J. F. P. (2). 2. 319. 4 Schneider. P. A. 138. 604. lj Karsten. 3. 25 Michaelis. Z. F. C. 13. 460. 5Mohs. See 11. 16Schiller. 6.367. 26 Dupr6. J. F. P. 21. 253. 6 Dana's Mineralogy. 17 S6chting. Dana's Miner- 27 Dupre. J. F. P. 21. 253. 7Schafarik. 28. alogy. 28 Lemoine. 17. 134. 8 Karsten. 3. 18 Dana's Mineralogy. 29 Lemoine. 17. 133. 9 Henry. 4. 756. 19 Boullay. 2. 30 Schafarik. 28. 10 Kuhlmann. 9. 832. 20 Karsten. 3. 31 Karsten. 3. 21 Tschermak. 27. 21 M3oore. J. F. P. (2). 2. 319. 32 Dana's Mineralogy. 62 SPECIFIC GRAVITY TABLES. Name. Formula. Specific Gravity. Boiling Point. Melting Point.' Arsenic trisulphide. As, S3. 3-4592 8 ({ 3-48. (3 U (( 3.48. 4 (C 3-405 Antimony t Sb2 S3. 4.62. Stibnite. 6 V (c 4.5I6.. 7 6 4 4.7520. a8 a ze 4. I5- Amorphous. 9 ( n 0 4.6I4, Black. Massive. ) 10 ( ( 4.64I, I67 6 )Powdered [ 11 U U ( 4.280. Red. 12 (( ( 4.42I. Precipitated. J 13Bismuth disulphide. Bi2 S2. 7.29. m. of 5. 14 (( trisulphide. Bi, S3, 7.591, 4~5.15 7.0001. 16 (( (( 7.807. 17,( (C (c 7.I6. Fr. Bolivia. 18 Carbon disulphide. C S2. 1.272. 19 (( c cc 1. z2693, I 5~? 46~6. 760 m. m. (20 a(( 46?9. 753 m.m. 21 Ue 8c. 4622. 769 m. m. 22 U CC 1.265. 45-. 23 ( (4 I.293I2, O.~ 479~ 755 8m.m 24 (C (( I.29858, O.~ m. of 2. 25 I6 (C se 1.27904, I0.~', 46.0 26 I.26652, I7.0 760m.m. 27 u, ) I.22743I, 46? m.of 3. J 28c (( 1.2661, 20.0 47?7~ 745' 5m.m "1 Tin monosulphide. Sn S. 4.8523. 30 (C 5.267. s1 CC (( 4-97332 disulphide. Sn S2. 4.415. 33 (( OC 4.600. 3 Thorium sulphide. Th S. 8.29. 6 AUTHORITIES. 1 Karsten. 3. 13 Werther. J. F. P. 27. 65. 23 Pierre. 15. 2 Mohs. Watts' Dictionary. 14 Herapath. 1. 24 H. L. Buff. 29. Hiiidinger. Dana's 15 Karsten. 3. 25 H.'L. Buff. 29. 4 Breithaupt. Mineralogy. 16 Wehrle. See 11. 26 H. L. Buff. 29. s Mohs. See 11. 17 Forbes. P. M. (4). 29. 4. 27 H. L. Buff. 29. 6 Hauy. Watts' Dictionary. 18 Berzelius & Marcet. Schw. 28 Haagen. 32. 7 Karsten. 3. J. 9. 284. 29 Karsten. 3. 8 Fuchs. Watts' Dictionary. 19 Gay Lussac. See 17. 0 Boullay. 2. 9 H. Rose. 6. 361 and 362. 20 Marx. Schw. J. 62. 460. 31Schneider. 10 H. Rose. 6. 361 and 362. 21 Andrews. See 17. 32Boullay. 2. "1 H. Rose. 6. 361 and 362. 22 Couerbe. A. C. Phys. (2). 33 Karsten. 3. 12 1 H. Rose. 6. 361 and 362. 61. 232. 34 Chydenius. 16. 195. SPECIFIC GRAVITY 1TABLES. 63 2d. SULPHARSENITES, SULPHARSENATES, SULPHANTIMONITES, AND SULPHOBISMUTHITES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. Proustite. 3 Ag2 S. As2 S3. 5.422-5.56. 2 Sartorite. Pb S. As2 S3. 5.405 32 < 5-3934 t zo 5.469. 6 Dufrenoysite. 2 Pb S. As,2 S3. 5.566. 46 (( (, 5-549. 7 (( (( 5.56I.' Binnite. 3 Cu2 S. 2As2 S. 4.477. 9Enargite. 3 Cu2 S. As2 S,. 4.362. 10 (c 4.430-4-445.,1' 4.39. Guayacanite. 12 4.37. 13 s(1 4.34. 14 (1 4.43. 15 Miargyrite. Ag2 S. Sb2 S3. 5.2 I4-5.242. I 16 Pyrargyrite. 3 Ag2 S. Sb2 S3. 5.7-5.9. 17 Stephanite. 5 Ag, S. Sb2 S,. 6.269. Fr.Przibrami'8 Zinkenite. Pb S. Sb2 S3. 5.30-5.35. 11 Boulangerite. 3 Pb S. Sb2 S3. 5.75-6.oo. 20 Meneghinite. 4 Pb S. Sb2 S3. 6.339-6.345. 21 Berthierite. Fe S. Sb2 S3. 4.043. 22 Chalcostibite. Cu2 S. Sb2 S3. 4.748. 23 (( 5.05. 24 Wittichenite. 3 Cu2 S. Bi2 S3. 4.3. [For Chiviatite, Plagionite, Brongniardite, Jamesonite, Frieslebenite, Bournonite, Tennantite, &c., See Dana.] AUTHORITIES. I Dana's Mineralogy. 8 Dana's Mineralogy. 18 Dana's Mineralogy. 2'Sartorius v. Walters- 9Kenngott. Dana's Miner- 19 Dana's Mineralogy. hausen. 8.914. alogy. 20 v. Rath. 20. 974. 3 Sartorius v. Walters- 10 Breithaupt. 3. 702. 21 Pettko. 1. 1159. hausen. 8. 914. "l Field. 12. 771. 22 H. Rose. t Dana's 4 Sartorius v. Walters- 12 v. Kobell. 18.872. 23 Breithaupt. I Mineralogy. hausen. 8.914.'3Root. 21. 998. 24 Hilger. 18. 870. 5 Landolt. Dana's Miner- 14 Burton. 21. 998. [See Dana for Kobellite, alogy. 15 Weisbach. 18. 869. Aikinite, Tetrahedrite, eDamour. A. C. Phys. (3). "6 Dana's MIineralogy. Geocronite, Polybasite, 14. 379. 17 Dana's Mineralogy. &c.] v7. Rath. 17. 827. 64 SPECIFIC GPA VITY TiBLES. 3d. MISCELLANEOUS DOUBLE AND TRIPLE SULPHIDES. Name. Formula. Specific Boiling Melting Gravity. Point. Point.'Thallium potassium sulphide. K, S. T1, S,3 4.263. 2 Iron potassium ( K2 S. Fe2 S,. 2.563. 3 Sodium platinum ( Na2 S. 3 Pt S. Pt S2. 6.27, 15.0 4 Potassium (( ( K2 S. 3 Pt S. Pt S2. 6.44, I 55 Stromeyerite. Ag2 S. Cu2 S. 6.26. 6 Pentlandite. Ni S. 2 Fe S,. 4.6. 7 Linn9eite. 2 Co S. Co S2. 4.8-5.0. 8 Sternbergite. Ag2 S. 3 Fe S. Fe S2. 4.215. 9 Chalcopyrite. Cu2 S. Fe S. Fe S2. 4.I85. 10 Barnhardtite. 2 Cu2, S. Fe S. Fe S2. 4.52I. "1 Homichlin. 3 Cu2 S. 3 Fe S. Fe S,. 4.472-4.480. 12 Cubanite. Cu2 S. Fe S. 3 Fe S,. 4.o026-4.042. 13 4.169. 4( 4.18. 5 Carrollite. Cu,2 S. Co S. Co. S,. 4.58. 16 4.85. "Gold and Silver sulphide. 2 Au, S,. 5 Ag, S. 8.159. [For many other native sulphides, see Dana.] IX. SELENIDES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. Silver selenide. Ag, Se. 8.oo.'9 Thallium selenide. T12 Se. 340.0 20 Lead (, Pb Se. 6.8. Native. 21 7.6-8.8. 22 8. I 154. 23 Iron sesquiselenide. Fe, Se,. 6.38. AUTHORITIES. 1 Schneider. P. A. 139. 661. 9 Forbes. 4. 759. 17 Muir. B. S. C. 18. 222. 2Preis. J. F. P. 107. 10. 10 Genth. 8. 910. 18G. Rose. P. A. 14. 471. 3Schneider. P. A. 138.604. 11Breithaupt. 12. 773.'9 Kuhlmann. 17. 255. 4 Schneider. P. A. 138. 604. 12 Breithaupt. P. A. 59. 325. 20 Zinken. P. A. 3. 274. 5 Kopp. 16. 5. 13 Booth. Dana's Min. 21 Dana's Mineralogy. 6 Scheerer. P. A. 58. 316. 14 Smith. 7. 810. 22Little. 12. 95. 7 Dana's Mineralogy. 15 Faber. 5. 840. 23 Little. 12. 94. 8 Dana's Mineralogy. 16 Smith & Brush. 6. 782. SPECIFIC GTRAITY TA.BLES. 65 Boiling Melting Name. Formula. Specific Gravity. Point. Point.' Nickel selenide. Ni Se. 8.462. 2Cobalt (( Co Se. 7.647. 3 Copper (( Cu Se. 6.655. 4Cadmium (( Cd Se. 8.789. 5 Mercurous Hg2 Se. 8.877. 6 Mercuric (( Hg Se. 7.274. From Tilkerode. 7 (( (( 7.I-7.37." Clausthal. 8 Arsenic triselenide. As2 Se3. 4.752 9 Bismuth ( Bi2 Se3. 6.82. 10 (1 7.406. " Tin monoselenide. Sn Se. 5.24. I 5.0 2 " diselenide. Sn Se. 5.1I33. 132 4.85. X. TELLURIDES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 14 Silver telluride. Ag2 Te. 8.565. 15 (( (( 8.412. 6 Lead Pb Te. 8, i 59. A7 ntimony tritelluride. Sb, Te3. 6.47-6.5 I. I3. 18 Bismuth Bi2 Tea. 7.237. 19 7.868. 20 ( ( (( 7.941. 21 (1 7.642, 18.~ AUTHORITIES. 1 Little. 12. 94. 8 Little. 12. 95. 15 G. Rose. P. A. 18. 64. 2 Little. 12. 94. 9 Schneider. 8. 386. 16 G. Rose. P. A. 18. 6(4. 3 Little. 12. 95. 10 Little. 12. 95. 17 B1deker and Giesecke. 26. 4 Little. 12. 94. 11 Schneider. J. F. P. 98.236. 18 Gelth. 5. 833. 5Little. 12. 95. 12 Little. 12. 94. 19 Jackson. 12. 770. 6 Dana's Mineralogy. 13 Schneider. J. F. P. 98. 236. 20 Genth. 13. 744. 7 Kerl. 5. 837. 14 G. Rose. P. A. 18. 64. 21 Balch. 16.794. 66 SPECIFIC GRAVITY TABLES. XI. PHOSPHIDES. Boiling Melting Name. Formula. Specific Gravity. Boiling Metin 1 Silver sesquiphosphide. Ag, P3. 4.63. 2 Chromium phosphide. Cr P. 4.68. 3Manganese (( Mn5 P2. 5.95I. A mixture? 4 ((,< ~ Mn, P. 4.94. 5 TIronll Fe3 P4. 5.04. 6 c Fe, P. 6.28. 7 Nickel Ni3 P2. 5.99.'Cobalt Co3 P2. 5.62. 9 Copper c, Cu, P. 6.75. 10 (( (( 6.5911 Palladium o Pd P,. 8.25. 12 Platinum (( Pt P2. 8.77. 13 Molybdenum M(( Io P. 6. I67. 24 Tungsten, W2 P. 5.207.'5 Zinc c Zn3 P2. 4.76. 16 Gold sesquiphosphide. Au, P,. 6.67. 17 Tin monophosphide. Sn P. 6.56. XII. ARSENIDES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 18 Kaneite. XMn As. 5.55.'9 Leucopyrite. Fe As2. 6.80. Fr. Andreasberg. 20 < = 2 Schwanert. 28 Kopp. 18. 9 Louguinine. 30. l~,. 19 (Warren. 18.515. 29 Kopp. 18. 10 Louguinine. 30. I 8 n 20 Warren. 18. 515. ao Mansfield. J. C. S. 1. 267. Louguinine. 30. j 21 Warren. 18. 515. 31Church P.PM. (4. 256. 22 Warren. 18. 515. 32 Mendelejeff. 13. 73.7. 126 SPECIFIC GRAVITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. ]Cymrol. CO H114..8664, 20.0 2 0 ) From (.8697, o.O ) (3 053 oil of..8724. o.~ I7975. cummin. a.8592, 14.0 6.8705, 0.0From 6 1From.8544, 20.0 7 j oil of.8302, 50. 175 -I76.~ 8 cummin. 0.7893, 1000. J "9 (( ) o.8732, 50.0 19 }. camphor,.8333, 50.0 1740-175 12 and PCI. (8.7919, }oo.J 13 From camphor. 1750-I78.0 14 Thynmo-cymol. (( I73.0 15 (( Etihyl xylol. ((.8783, 20.0 I830-I84.0 16 (( Diethyl benzol..8707, I 5"5 I78~-I79.0 17 (( Isobutyl benzol. (( 3577, 16.0 159~-161.~ 18 Tetra methyl benzol (( I89-I9 I.0 78-80.0 9Amvl benzol. C1 HI.859, I2.0 I95.0 20 Diethyl toluol..(( 87 5 I, 0.0 178.~ 21 Laurol. 5.887, Io0. 188.0 22 Amyl toluol. C12 H18.8643, 9.0 213.0 23 Amyl xylol, C13 H20..895 I, 9.~ 232~-233.0 [For mesitylene, see miscellaneous hydrocarbons.] AUTHORITIES. I Williams. J. C. S. 15. 120. 9 Louguinine 30. 5' 17 Riess. Z. F. C. 14. 3 2 f arrel. Me. Amer. Louguinine. 30.. 7, Z. FI. F.C. Acad1 Louguinine. 30. 1 3.61. 3 Warren. Mem. Amer. 12 (Louguinine. 30. J 19 Tollens & Fittig. A. C. P. Acad. 9. 154. 13 Louginine and Lippmann. 131. 303. 4 WTarren. Mem. Amer. 20. 700. 20 LippnlaIn & Loug3uinine. Acad. 9.154. 4"Carstanljen. J. F. P. (2). 20. 667. 5 rLouguinine. 30. o -= a5C 3. 50. 21 Fitti-, K6brich & Jilke. 20. 6 Louguinine. 30. 15 Ernst & Fittig. A. C. P. 01. Louguinine139.192. [144. 285m. e.22 Bigot & Fittig. 20. 667. 18 Louguinine. 30. J 8 16 Fittig & Kinig. A. C. P. 13 Bigot & Fittig. 20. 697. Acd 9. 15.1 ognieadLpman 3.3 SPECIFIC GPRAViTY TABLLES. 127 5th. C10 H16 AND ITS ISOMERS. Chiefly Hydrocarbons from Essential Oils. Name. Formula. Specific Gravity. Boiling Melting Name._~~~~~~~ ~Point. Point. [For valerylene and isoprene, see miscellaneous hydrocarbons.] From oil of anise. C10 H16.8580, 20.0 I60.0 2 Geraniene..842-.843, 20.~ I62~-I64.0 3 From oil of neroli. e.8466, 20.0 I73.0 4 (( cc petit grain..8470, 20.0 I74.~ 5, orange peel..( 846o, 0 6cc cc~ c~ ( (1( ~.8468, 20. 7 fruit of Citrus lumia.. 853, 18.0 I80.~ 8 <,,,, bigaradia. (.8520, I0.0 9 ({ ~c (( (.8517, 12. 178.2 10 R, medica.). 10 " medica.) ((.8514, 15. 55 (?) 11, oil of cedrat..8466, 20.~ I73.0 12 0 bergamot. c.864, o 17 o C.8380, o.0 18 ( CC (C.866I, o.0' 19 e (( CC.8468, 20. 173.~ 20 Citrene. c.8 569. I65.0 2' Cicutene. Fr. Cicuta virosa. 87038, I 8.0 1 66.0 22 From oil of parsley. e.8732, 20.0 I 60.0 23 ", 0 cummnin..( 8772, 0.0 I55~8. 24 s e (C CC.8657, I5.0 15 58. 25 g( z galbanum. s.8842, 9.0 I60.0 26 caraway..8466, 20.0 176.0 27 Carvene. e.86I, 15.0 I75O-I78.~ 28 ( 8530., 20. 166.0 29 cc~~ (C.8545,9 -. AUTHORITIES. 1 Gladstone. C. S. J. 17. 1. 1 Gladstone. C. S. J. 17. 1. 20 Watts' Dictionary. 2 Jacobsen. Z. F. C. 14. 17 1. 12 Gladstone. C. S. J. 17. 1. 21Van Ankum. 21. 794. 3Gladstone. C. S. J. 17. 1. 13 } Gladstone. C. S. J. 17. 1. 22 Gladstone. C. S. J. 17. 1. 4 Gladstone. C. S. J. 17. 1. 14 Zeller. Watts' Dictionary. 23 Warren. 18. 515. Gladstone. C. S. J. 17. 1. 15 Blanehet &Sell. Watts 24 Warren. 18.515. Gladstone. C. S. J. 17. 1. 16 Brix. jDictionary 25 Mossmer. 14. 687. 7 Luca. 13. 479. 17 (Frankenheinl. 1. 68. 26 Gladstone. C. S. J. 17. 1. 8f Luca. C. R. 45. 904. 18 Two samples of sub- 27 Ydlckel. 6. 512. 9 Luca. C. R. 45. 904. stance. 28 f Gladstone. C. S. J. 17.1. 10Berthelot. 6. 521. 19 Gladstone. C. S. J. 17. 1. 29 Gladstone. C. S. J. 17. 1. 128 SPECIFIC GRA VITY TA;lLES. Boiling Melting Name. Formula. Specific Gravity. oiling Meint.'From oil of dill. C1U H16..8467, 20.0 I73-0 2 (( elder. C (.8468, 20.0 I72.0 Safrene..(( 8345, 0.o I 55~-I 57.0 4 From oil of wormwood..8565, 20.0 I60.0 5 ct ct mint. ot.8600, 20.0 i6o.0 6 (,, peppermint. (t.8602, 20.0 I75.~ 8hmnc7 ( thyme.} (.8635, 20.~ I60.~ 8 Thymene. f(.868, 20.0 I60~-I65.~ 9Gaultherilene. (.85I0, 20.0 168.0 10 From oil of rosemary. s.8805, 20. I63.0 11 Cinabene. (.878. I72.0 12 Cynene. (?) ~.825, i6.0 I73~-I75.~ "3 From oil of nutmegs..858 166 14. (( 20. 166~-167.0 15,, < bay. o.908, I 5.0 64.16 ( (.8508, 20. 171.~ 17 u, birch tar. (c.870, 20.0 I56.~ 18 (( (( cascarilla. o.8467, 20.0 I72.0 19 0 a myrtle. (.8690, 20.0 I63.~ 20 ((laurel turpentine..86i8, 20.0 I60.~ 21 ( Eucalyptus amygdalina..8642, 20.0 I71.~ 22 (Ptychotis ajowan..854, I2.0 I72.0 23 elemi..849, I.~0 I74.0 24 ((.852, 24.0 166.0 25 Olibene..863, 12.~ 156~-158.0 26 Cajeputene..850, I5.0 I60-I65.~0 27 Isocajeputene..857, 16.0 I76~-I78.~ 28 By distillation of copal oil. ((.951, I o. I60o~-I65.0 29 Caoutchin..842, 20.0 171.0 30 To]ene..858, IO.~ I54~-I60.~ 31 ((70. 32 Xanthoxylene. I62.0 33 From Pinus maritima. ".864, 16.0 80~-Ioo.0 34 cc (( pumilis..875, I7.0 I61.0 AUTHORITIES. 1 Gladstone. C. S. J. 17. 1. 13 Gladstone. C. S. J. 17.. 25 Kurbatow. Z. F. C. 14. 2 Gladstone. C. S. J. 17. 1. 14 Gladstone. C. S. J. 17. 1. 201. 3 Grimaux and Ruotte. 15 Bias. 18. 569. 26 Schmidl. 13. 481. 4 Gladstone. C. S. J. 17. 1. 16 Gladstone. C. S. J, 17. 1. 27 Schmidl. 13. 482. 5 Gladstone. C. S. J. 17. 1. 17 Sobrero. Watts' Dictionary. 28 Schibler. 12. 516. 6 Gladstone, C. S. J. 17. 1. 18 Gladstone. C. S. J. 17. 1. 29 Williams. 13. 495. 7 Gladstone. C. S. J. 17. 1. 19 Gladstone. C. S. J. 17. 1. 30 E. Kopp. 1. 737. 8Lallenland. 9. 616. 20 Gladstone. C. S. J. 17. 1. 31Scharling. 9. 627. 9 Gladstone. C. S. J. 17. 1. 21 Gladstone. C. S. J. 17.. "3Stenhouse. Watts' Dic10 Gladstone. C. S. J. 17.1. 22 Stenlhouse. 9. 624. tionary. T-irzel. 7. 592. 23 Deville. 2. 448. 33 Berthelot. 6.519. Vi61ckel. A. C. P. 89. 358. 24 Stenhouse. A. C. P. 35. 304. 34 Buchner. 13. 479. SPECIFIC GRA VITY TABLES. 129 Boiling Melting Name. Formula. Specific Gravity. Point. Point'From Pinus picea. C10 H16..859, 6.~0 I68~-I73.~ 2 (( abies..856, 20.0 I67.0 3, Abies Regine Amalive..868. I56~-I92.~ 4 Oil of turpentine..8902, 0.0 5.880. 165.~ 6.8644. [ Four,.*8555. I20~ 8 (( (( samples..86I4. 2 9 (( J ((.8600. J'0 Terebene..87 I 8. I 7 I 11.864. 156.~ 12 (( I 60. 13 S(.8583, 20.0 I60.0 14 Isoterebenthene. (.8432, 22.0 I76~-I78.0 15 Austrapyrolene..847. I77.0 16 Terebilene..843. I34.0 17 Camphilene..87. I 56.~ 18 Sesquiterebene. C15 H24. 250.0 19 Metatemplene. (( I.037, 4 0 280.0 20 Para-copaiva oil..9 1. 252.0 p. d. 21 From Maracaibo balsam. (.921, I0.0 2500-260.0 22 (( Gurgun (.9044, I5-. 255.0 23 ( Drybalanops camphora..9-92I, 20.~0 2550-270.0 24 oil of cloves. (.9I8, I8.~ I42- I43.0 (( (C o( ((.9016, I4.0 25I.~ 26 ( ({.904I, 20.0 249.0 27 (( cubebs. (.915; 930; 938. 250.0 28 (( (( ((.929. 250~-260.~ 29 (( (( ((.9062, 20.0 260.0 30 Myrtus pimenta. i.98, 8.0 255.0 31 Laurus nobilis. (.925, I5.~ 250.0 2 oil of rosewood. (.9042, 20.0 249.0 33(( (( calamus. i.9I80, 20.0 260.0 34 ( ( (((.9275,) AUTHORITIES. 1 Flickiger. 8. 643. 13 Gladstone. C. S. J. 17. 1. 24Ettling. Watts' Dictionary. 2 Wdhler. 14 Berthelot. 6. 523. 25 Williams. 11. 442. 3 Buchner & Theil. 17. 536. 15 Watts' Dictionary. 26 Gladstone. C. S. J. 17. 1. 4 Frankenheim. 1. 68. 16 Watts' Dictionary. 27 Schmidt. 5 Blanchet and Sell. 17 Watts' Dictionary. Vol. 5. 28 Watts' Dictionary. 6 r Gladstone. C. S. J. 17.1. 925. 29Gladstone. C. S. J. 17. 1. 7 Gladstone. C. S. J. 17.1. 18 Berthelot. 15. 457. 00 eser. 17. 534. 8 I Gladstone. C. S. J. 17. 1. 1.'9 Fliickiger. 8. 646. 31 Blas. 18. 569.`9 Gladstone. C. S. J. 17.1. 20 Posselt. 2. 455. 32 Gladstone. C. S. J. 17. 1. 10 Pierre. 4. 52. 21 Strauss. 21. 795. 33 f Gladstone. C. S. J. 17. 1. " Watts' Dictionary. 22 Werner. 15. 461. 34} Gladstone. C. S. J. 17. 1. 12 Berthelot. 15. 457. 23 Lallemand. 12. 503. 130 SPECIFIC GRAVITY TABLES. Boiling Melting Name. Formula. Specific Gravity. Point. Point. 1From oil of cascarilla. C15 H24..92 I 2, 20.~ 254.0 2 (( (, patchouli..92 I, 254.0 3 (( (( (( ((.9278, 20. 257.o 4 (C (C (C CC.9255, ) 260.0 5 Diterebene. C20 H32. 94. 3I00-3I 5.0 6retalterebenthene. ((.913, 20.0 a. 360.~ 7 Colopheue. ((.939I, 20. 3I 5.~ 8 ((.94. 310.~ 9 He-eene. ((.921, 21. 3I5.0 6th. MISCELLANEOUS HYDROCARBONS. Boiling Melting Name. Formula. Specific Gravity. Poiling Meltint. 0 Diallyl. (C3 115)H..684, I4.0 59.0 ii (( C(.68724, I7.0 m. of 4. 1 580 12 ( (.64682, 5995. m. of 2. ) to 13 (( ((.64564, 58.0 m. of 2. 1 59.5. 14 HeSoylene. C6 H1i.7Io0, I3.0 76~-80~ I Clarbo dinrethyl diethyl. C7 11,,..71II, 86-8. 16 C 6, 2( 860-87.'.6958, 2005' 17 Cinnamene, or Styrol. C8 H..928, I 5 I44.0 18 (( ((.924. I4575. ((19 (C ((.876-.896, i6. I 40.0 20 lMetatcinnanene. ( I 054, I3-0 S. 21 Valerylene. C5 H. 440 —46.~ 22 (( (.69999, o.~ 23 ", ((.687386, I7.~ m. of 2. 1 4 -420,,24 ((.65719, 4I.~ m. of 2. j 25 (C.65o82, 42.0 J 26 Trivalerylene. (Cs H8)3..862, I5.0 265~-275.0 27 Isopr'elle. C5 118..6823, 20.0 37 -38.0 28 Valvlene. C5 Hr. a. 50.~ AUTHORITIES. Gladstone. C. S. J. 17. 1. 1 i H. L. Buff. 29. 19 Scharling. A. C. P. 97. 12,. 2 Gladstone. Buff. 29. 20Scharling. A. C. P.97. 1.Bu 3 Gladstone. C. S. J. 17. 1. 13 H. L. Buff. 29. 21 Reboul. 17. 506. 4 Gladstone. C. S. J. 17. 1. 14 Reboul & Truchot. 20. 587. 22 H. L. Buff. 29. 5 Watts' Dictionary. 15 Friedel and Ladenburg. 23 H. L. Buff. 29. 6 Berthelot. 6. 524. I J. F. P. 101. 315. 26 H. L. Buff. 29. 7 Gladstone. C. S. J. 17. 1. 16 l Friedel and Ladenburg. 25 [ H. L. Buff. 29. 8 Deville. J. F. P. 101. 315. 26 Reboul. 20. 585. 9 Bouchardat. A. C. P.37.30. 17 E. Kopp. J. F. P. 37. 283. 27 Williams. 13. 495. ~0 Berthllelot & Luca. 1. 590. 18 Blyth & Hoffmrann. A. C. 28 Reboul. 18. 510. P. 53. 294. SPECIFIC GRAVITY TABLES. 131 Name. Formula. Specific Gravity. Boiling Pelting Point. Point. Ethyl vinyl. C4 H8. -5. 2Caoutchene. (.65,-2.~ I4~5. — IO.~ 3 Menthene. C1O H18..85I, 2I.~ I63.0 4 (( (z I163.0 5Rutylene. a. I50.0 6Crotonylene. C4 H6. I8.~ 7 Conylene. C8 H14..76076, 15. 126.0 8Fromi Camphoric acid. (.814, o. I I9.0 9Benylene. C15 H28..9II4, o0. 2230-228.0 10Eucalyptene. C12 H18. 836, I2.~ I65.0 1"Camiphin. C18 H32. 827, 25.~ I67~-I70.~ 12 Cedrlene. C16 H241.984, 1405. 248.0 13 Mesitylene. C9 H12. I 55~-I60.~ 14 (1 I62O-I 64.~ 15 ic 163.0 16 Dibenzyl. C14 114. 284.0 S. 515-52~5. 17 I( 1.002, I4.0 282.0 1 ((8.9945, IO5~ 272.0 19 52.5-5305. 20 Naphthlaline. 1. C1O H8..9774, 792. m Of 3. 21 604-2 1608. 79~2. 21 (( 1. ((.9628, 9922. 7991. I 22 (C 2 I 2.0 79.0 23 (( (( 24 S. 1.15173, I9.0 26 (( S. (( 25 S. ( 1.153, 18.0 26 (( S. It 1.048. 27 (( [dride. (( 81.0 28 Naphthaline tetrahy- C0O H12..98 I, I2.0 205.0 29Methyl naphthaline. 1. C11 I10. 1.0287, II~.5. 23I~-232.~ 30 Ethyl 1. C12 12. 1.0184, IO.0 25I~-252.0 31 Anthracene. C14 H 3000+ I80.0 32 ( (I I47. (c 21323. AUTHORITIES. 1 Wurtz. A. C. P. 152. 20. 13 I1ofmnann. C. S. J. 2. 104. 24 Vohl. 2 Bouchardat. A. C. P. 37.30. 14Cahours. C. S. J. 3.17. 25 Watts' Dictionary. 3Walter. A. C. P. 32. 288. 15 Fittig. 26 Weltzien's " Zusammens4 Oppenheim. C. S. J. 15. 29. 16 Cannizzaro& Rossi. 14. 548. stellung." 5 Bauer. A. C. P. 135. 344. 17 Limpricht. 19. 593. 27 Lowe. D. P. J. 201. 250. 6 Caventou. A. C. P. 127.347. 18 Fittig. A. C. P. 139. 178. 28s Graebe. B. S. C. 18. 205. 7 Wertheim. A.C.P. 123. 157. 19 Wurtz. A. C. P. 7th. supp. 29 Fittig & Remsen. A. C. P. 8 Wreden. A. C. P. 163. 337. 54. 155. 114. 9 Bauer & Verson. 21. 337. 20 Kopp. 18. 30 Fittig & Remsen. A. C. P. 10 Cloz. 21 Alluard. 12. 472. 155. 118. [189. n1 Claus. J. F. P. 25. 269. 22 Dunmas. A. C. Phys. (2). 31 Dumas. A. C. Phys. (2). 50. 12 Walter. A. C. Phys. (3). 1. 50. 182. [14.111. 2 Reichenbach. Watts'Dict. 501. 23 Gerhardt. A. C. Phys. (3). 13 Anderson. C. S. J. 15. 44. 132 SPECIFIC GRAVITY TABLES. Name. Formula. Specific Gravity. Boiling Melting N.Formula.Specific Grav Point. Point. Point. Point. 1 Anthracene. C14 H1o. 3600+. 2I3.~ 2Anthracene dihydride. C1, H12. 305-0 I06.~ 3 (( hexhydride. C14 H16. 290.0 63.0 4Stilbene. C14 H12. I25.~ (( (( II5~-II8.~ 6 Pyrene. C16 H10. I70~-I80.~ (7 C142.~ 8Chrysene. ( 230-235.0' Paranicene. CI0 H12. 1.24. 365.0'0 Retene. C18 Hs 98~-99.~ 11 K6nlite. (C6 H6)1n..88. I07~5. 12 I 1I4.0 13 Scheererite. (C H4)n. I.O-I.2. near Ioo. 44. 14 Hartite. (C3 H5)n. I.o46. 74.0 AUTHORITIES.' Graebe & Liebermann. Z. 5 Wurtz. A. C. P. 7th. supp. 9 St. Evre. 1. 532. F. C. 13. 257. 54. 10 Fehling. A. C. P. 106. 388. 2Graebe & Liebermann. Z. 6 Laurent. A. C. Phys. (2). 11 Tronmmsdorf. A. C. P. 21. F. C. 13. 257. 66. 136. 126. 3 Graebe & Liebermann. Z. 7 Graebe. J. F. P. (n. s.) 2. 12 Kraus. P. A. 43. 141. F. C. 13. 257. 186. [66.136. 13Dana's Mineralogy. 4 Howard. s Laurent. A. C. Phys. (2). 14 Haidinger. P. A. 54. 261. SPECIFIC GRAVIfTY TIABLES. 133 XL. COMPOUNDS CONTAINING C H, AND O. 1st. ALCOHOLS OF THE ETHYLIC SERIES. NOTE.-For common alcohol there is such a great number of determinations, both of Specific Gravity and Boiling Point, that the compiler has not thought it necessary or advisable to attempt to give them all. Therefore only the more important determinations for this substance are given. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 1 Metbyl alcohol. C II4 0..798, 20.~ 6605. 2 (C 600, 744 m.m. 3 (C (C.807, 9.0 (( (( ((.813. 5 (( (C ((.82074, 0.0 663~. 6 (C.7938, 25.0 ~7 (( se (( ~.8 17 96, 0~ 655 8 ( ( ((.80307, I6 6 595 09 C (( 6598. 10 o 66?5. 11 (( (( ((.8o65, 15.0 12 (( (( ((.8052, 905. 605~. 13 (( (( ((.8142, 0. 14 CC zz ((.7997, I604. 15 C( (( (( *.8574, 21.~ 66~-66?5. 16 ((.8I57, 10.~0 586. 17 Ethyl " C.2 H6 0..7924, I7"9. 7804. 18 C( ((.( 79I5, I8.~ 76.~ 19 (( (( ((.8095, o.o 78 I-79.~0 20 C(( ((..7996, I 5. 7878. 21 CC (( ((.81087, o.0 23 o z.8095, o.O 23 C 798C.821' 14 78 24 C ((.(( 7990, 1408. J AUTHORITIES. 1Dumas & Peligot. A. C. 9Andrews. 1. 89. 18 Dumas & Boullay. P. A. Phys. (2). 58. 5. l0 Person. 1. 91. 12.93. 2 Kane. A. C. P. 19. 164. 1 Mendelejeff. 13. 7. 19 Darling. 3 Deville. See 13. 12 Delffs. 7.26. 20 Kopp. A. C. P. 55. 166. 4 Regnault. 13 Kopp. 18. 21 Kopp. 13. 5 Pierre. 43. 14 Kopp. 18. 22 Kopp. 13. 6 Kopp. A. C. P. 55.166. 15 Linnemann. 21. 81. 23 Kopp. 13. 7 ~ Kopp. 13. 16 Dupr6. P. A. 148. 236. 24 Kopp. 13. 8 Kopp. 13. 17 Gay-Lussac. 134 SPECIFIC G-IAVITY TABLES. Name. Formula. Specific Gravity. Poilingt. Polint. 1 Ethyl alcohol. C2 1160..8151, 0. 78.3. 2 (( 779~ 7804. 4 (( ((,.7938, 1505. 8006. 5 ( (( 897 0 6 ( (O (('.7905. J 7 (( (( ((.7938I, I 56. 8 (( ((.809, 5-. 78.25. 9 (( (( ((.8194, 19.0 8I.~ 10o ( 0 0.6796, 130.9. l (c ~(.7947, I 5.0 12 (( c ((.7946.) 05 c(( ((.7947.) 14 c cc.80625, o.~ 15 (( ((.80207, 5.~0 16 cc ((.79788, Io.O 7803~ 17 ((.79367, I 5.0 to 18 (t (( ((c.78945, 20.0 780 19 (( (( ((.78522, 25.0 20 cc cc ((.78096, 30.0 J 21 cc O cc.8086, Ig.0 77~-7795. 22 Propyl' iso. C3 18 O..79I, I5.~ 83~-84.~0 23 (( (( (.7915, I6?5. 830-85.0 i24 c cc c.820, O. 1 25 (( (( ((.812, I003. 26 9805. 20 r cc I cc ~~ cc.780, 51 I. 9 27 cc cc ((.749, 840 J 28 (( (( ((.813, I3.0 97-IOI.~ 29 (( ((.812, I 6.~ 970 9830 cc (( ((.823, o~- 96.~ 31 (( (( ((.8205, 0.0 96o-97.0 32 Buntyl (( C4 O110.8032, I805. IO9.0:33.8I7,,, 34 (( ((.809, II. I07?5. AIJTHORITIES. 1Pierre. 43. 12 J v. Baumhauer. 13. 393. 24 (Pierre cf Puchot. 21. 434. 2 Andrews. 1.89. 13 v. Baumhauer. 13. 393. 25 Pierre& Puchot. 21.434. 3 Person. 1. 91. 14 MIendelejeff. 18. 469. 26 ~ Pierre & Puchot. 21. 434. 4 Fownes. P. T. 1847. 249. 1s AMendelejeff. 18.469. 27 Pierre & Puchot. 21.434. 5 ( Wackenroder. 1. 682. 16 Mendelejeff. 18.469. 28 Chancel. A. C. P. 151.302. Wackenroder. 1. 682. 17 Mendelejeff. 18. 469. 29 Chapman & Smith. C. S. J. 7 Drinkwater. 1. 682. 18 Mendelejeff. 18.469. 22. 194. 8 Delfts. 7. 26. 19 Mendelejeff. 18.469. 30 Saytzeff. Z. F. C. 13. 107. W\etlerill. J. F. P. 60.20. 20 2 Mendelejeff. 18. 469. 31 Rossi. A. C. P. 159. 79. 70o Mecidelejeff. 14. 20. 21 Linnemann. 21.413. 32Wurtz. A. C. P. 93. 107.:' Pouilet. 12. 439. 22 Linnemann. 18. 48. 33 ( Pierre & Puchot. 21. 434. 23 Siersch. A. C. P. 144. 141. 34 Pierre & Puchot. 21. 434. SPECIFIC GRA ViTY TABLES. 135 Name. Formula. Specific Gravity. Boiling Melting Point. Point. 1Butyl alcohol. C4 H1lo 774- 55 I 2 (( (( ((10795..732 2, I O.j 3 (( ({ *.80o55, i6o8. 10895. 4 ( <( ((.826, o.0 I 15O~-1 6.~ 6 (( (C ((.8239, o.~ 6 (C.8105, 20.0 7 (C (C (C.7994, 40.0 1 I6.~ 8 (C C.7738, 98~7~. 9 (C (C (C.7735, 98'9~ 10 (( iso. (C.85, 0o. 96~-98.0 11 (C (.827, o. 99 12.810, 22.} 99. 13 (C (( 0 (C.8003, i8.0 Io8939. 14 Anyl o C5 H12..8I84, 15.- 1 32 la Th.8I37, 15.~ 133.0 16 ( ( ((.827I, 0.0 I3IO8. 17,, (( ((.8i85, 15.0 134.0 0189 (( (( ((.8144, 1 599. 19 (( 43 219 l {.8127, I6?4 20.8 127, 16~4. 760. m. m. 21 (( ((.8253, 0.~ mean. c22 cc (( 132.~ 23 (( (t.8 8, 14.0 I32.~ 24 (( (C I270-I29.0 25 ".8248,.0~ 25 (( (( 0 811348 o. } I30o9-I3I96. 26 ( (C.8II3, I8?7. 27 (( ((.8 9, I 8. 28 (( (( (.8142, 15. 29 (( ((.8296, o.~ 30 (( ((.8 68, 20.~ 137.0 31 (.8o65, 4o. 740. m. m. 32 ( ( ((.7835, 99915. AUTHORITIES. Pierre&Puchot. 21.434. 10 De Luynes. A. C. Phys. 22 Person. 1. 91. 2 Pierre & Puchot. 21. 434. (4). 2. 424. 23 Delffs. 7. 26. 3 Chapman & Smith. C. S. J. 11 { Lieben. A. C. P. 150. 114. 24 Pasteur. 8. 615. 22. 161. 12 Liebent. A. C P. 150. 114. 25 IKopp. 18. 4 Saytzeff. Z. F. C. 13. 108. 13 Linnemann. A. C. P. 160. 26 j Kopp. 18. 5 ( Lieben & Rossi. A. C. P. 195. 27 Schiff. 158. 137. [158.137. 14 Cahours. A. C. P. 30. 288. 28a endelejeff. 13. 7. 6 Lieben & Rossi. A. C. P. 15 Kopp. A. C. P. 55.166. 29 Lieben & Rossi. A. C. P 7 Lieben & Rossi. A.C.P. 16 Pierre. 1.62. 159. 70. [159. 7C 158. 137. [158. 137. 17 Rieckher. 1.698. 30 Lieben & Rossi. A. C. P 8 Lieben & Rossi. A. C. P. 18 ( Kopp. 13. 31 Lieben & Rossi. A. C. F 9 Lieben & Rossi. A. C. P. 19 I Kopp. 13. 159. 70. [159. 7C 158. 137. 20 Kopp.32 13. 1 Lieben & Rossi. A. C. 1F 21 [ Kopp. 13. 136 SPECIFIC GRAVITY TABLES. Name. Formula.l Specific Gravity. Boiling Melting Point. Point. Aniyl alcohol. iso. C5 H12 0..8249,) ~ 120. 2 ( (( (( ((.826o, ~ 759 m. m. [For amylene hydrate, see miscellaneous compounds of the Ethylene Series.] 3 Hexyl alcohol. C..833, 0. } 483-I 54.0 (4 ( ((.754, Io.O 5 ( ( (.820, 17.0 I 50~-I 52.~0 6 ( (( ((.813, 0.~ I5~-I 56.0 7 (( (( ((.81 9. I 56?6. 8.3 ((. ((.8327,. ) (( (( C (.8209, I6.~ I 37.0 10 Cc ( ((.7482, 99.0 755 5 m. m. " Heptyl C7 H16 0. 792, i6~5. I78.0 12,..8I9, 23. I770-I77513 C ( I78.5. 14 (( (65. 15 (( ((5~-1I60.~ 16 1( (( ]Products (.829I, I3.5. I63~-I65.~ 17 (( from four H.8286, I9~5. I640-I67.~ 18 j different.(( 795, I5-0 I63~-I68.0 19 ( j sources. ((.8479, I6.~ 64~5. 20 Octyl (C8 H18 0..823, I710 379.0 21 3178.0 22 179.0 23.826, I6.0 I80~-I84.0 24 ( (( 8. 25 C 830. I6.0 1900-I92.~ 26 196~-I97-~ 27 Decatyl alcohol. C0 H1122 0..8569, o.0 203~3. 28 Endecatyl ( Secondary. C,, H24 O..8268, I9.0 2280-229.0 29 Cetyl C16 H34 O. s. 48.0 AUTHORITIES. 1 J Wurtz.. Z. F. C. 11. 490. 11 Wills. 6. 508. 21 Moschnin. J. F. P. 60. 207. 2 Wurtz. Z.F.C. 11.490. 12 Stiideler. 10. 361. 22Squire. 7.583. 3 { Faget. 6. 504. 13 Petersen. 14.612. 23Pelouze and Cahours. 16. 4 Faget. 6. 504. 14 Bouis & Carlet. 15. 413. 529. 5 Pelouze & Cahours. 16.527. 15 Faget. 15. 412. 24 Schorlemmer. 21. 447. 6 Buff. 21. 336. 16 Schorlemmer. A. C. P. 25 Zincke. Z. F. C. 12. 55. 7 Franchimont and Zincke. 136. 257. [136.257. 26 Renesse. A. C. P. 166. 82. Chem. News. 24. 263. 17 Schorlemmer. A. C. P. 27 Borodine. 17. 338. 8 (Wanklyn &Erlenmeyer. 18is Schorlemmer. A. C. P. 28A. Giesecke. Z. F. C. 13. 16. 521. [16. 521. 136. 257. [136. 257. 431. 9 Wanklyn & Erlenmeyer. 19 [ Schorlemmer. A. C. P. 29 Chevreul. Watts' Dic10 [ Wanklyn & Erlenmeyer. 20 Bouis. 7. 581. tionary. 1 16.521. SPECIFIC GRAVITY TABLES. 137 Name. Formula. Specific Gravity. Point. Potint. 1Cetyl alcohol. C16 H3 0. s. 49~-49?5. 2Ceryl C7 H56 079. 3 Myricyl C30 H62 0. 85.0 2d. OXIDES OF THE ETHYL SERIES. Name. Formula. Specific Gravity. Boiling Melting 4 Methyl oxide. C2 H6 0. -21.0 (( (, -23965. 6.Methyl ethyl oxide. Ca H8 0. I I.~ 7 (1 7 (( (( (( (( I I.o s Ethyl oxide. CH1,,O..7 I9, 248. 35~79 -713, 20.~ 34-0 10o 1.733, I295. 11 (.73568, o. 39 12.72895, 6?9. m. of 2. 34 9 13 (.73574, o.~0 3505~ 16 (( (( (( 34~9. 15 ( 35?6. 16 0 (C.728, 7.0 35-0 17.73644, o.~ m. of 2.) 18 (( (( ((.63987, 78?3. 19 (C.60896, 9999. 20 (.55958, 131i6. 21 ( ( ((.51735, I570 22 ((.727I, Io.2. 23 (C.7204, 15.8.r 24 Ethyl propyl oxide. C5 H12 O..7447, 0. 540_55. 25, butyl C6 H14 O..7507, 0o.~0 78-80.0 26.761, o.0 9I 5-9205. 27 ( (.7694, o0.0 28 (( (( (( ((.7522, 20.0 91.7. 29.7367, 40. 742.7 m. m. AUTHORITIES. 1 Heintz. P. A. 84. 232. 11 Kopp. 13. 22 1 Matthiessen & Hockin. 2 Brodie. 1. 707. 12 Kopp. 13. 23 M iatthiessen & Hockin. 3 Kekule's " Lehrbuch." 13 Pierre. 15. 24 Morkownikoff. A. C. P. 4 Berthelot. Watts' Dict. 14 Andrews. 1. 89. 138. 374. 5 Regnault. 16. 70. 15 Person. 1. 91. 25 WVurtz. 7. 574. 6Williamson. 4. 511. 1 Delffs. 7. 26. 26 Saytzeff. 7 Wurtz. 9. 563. 17 rMendelejeff. 57. a 27 Lieben & Rossi. A. C. P. 8 Gay Lussac. 18 |Mendelejeff. 57. 1, 158.137. [158. 137. Dumas & Boullay. A. C. 9 endelejef. 57. Lieben & Rossi. A. C. P. 20c 29 Lieben &Rossi. A.C. P. Phys. (2). 36. 294. 20 Mendelejeff. 57. c 29 Lieben & Rossi. A. C. P.'O Muncke. 36. 21 Mlendelejeff. 57. J O 158. 137. 10 138 SPECIFIC GRA VITY TABLLS. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 1 Methyl amyl oxide. C6 H14 0. 92.~0 4 c (c c( (c.8036, 1407. ( c ((.7640, i8.0 I I2.0 [Compare with amylene ethylate.] 6 Ethyl hexyl oxide. C8 1118 0. 7752, 165.) 7 c (( ((.7638, 30.0 I3I~-I33.0 8 (( ((.7344, 63- 9 ( (c (c 0.776, I3.0 I 32-I 34.0 o ethyl heptyl ( 830, i65. I60o5-I6 I.0 aEthyl C H,, 0..79, I6.0 177.0 12 Amyl C1O H22. 779. I750-I83.0 13 ((.7994, ~-o I70~-I75.0'4 Amyl heptyl C12 H26 0..60o8,20.0 2200-22 I.0' Hesyl ((. 203~5-208?5 16 Ethyl cetyl " 1C8 138 0. 20.0 17 Amnyl ~C21 1144 0. 30.0 Cetyl ( C32 H6 0. 55 3d. ACIDS OF THE FORMIC SERIES. C. H2n 03. Name. Formula. Specific Gravity. Boiling Melting 9pcii Gait. Point. Point. 19Formic acid. C H2 10. 1.2353, I2.0 98~5. cc20 (c 8< I1.2227, 0.0 1053I o3. 21 ( (( 9 I.2067, I307- 760 m. m. 22 ( 0 9 I 00.0 23 I I.0 24 ( E I0I. c2(. 1 I.22 11, 20.0 99?8-Io003. 26 (( Is.2211 0 27 C( ( O.2.65,0 20.0 AUTHORITIES. Williamson. 4. 511. Reboul & Truchot. 20. 582. 19 Liebig. See 13. 2 Williamson. 4. 511.' Wills. 6. 510. 20 J Kopp. 13. 3 Guthrie. 10. 428. Wills. 6.510. 21 Kopp. 13. 4 Mendelejeff. 13. 7. 12 Rieckher. 1. 698. 22Person. 1. 91. 5 Reboul & Truchot. 20.582. 13 Wurtz. 9. 564. 23 Watts' Dictionary. 6 I Schorlemmner. J. C. S. 14 Will. 6. 510. [16. 521. 24 Roscoe. C. S. J. 15. 270. 19. 357. [19. 357. 15 Wanklyn and Erlenmeyer. 25 Landolt. P. A. 117. 353. 7 Schorlemmer. J. C. S. 16 Becker. A. C. P. 102. 220. 26 Semenoff. A. C. Ph-ys. (4) 8 Schorlemmer..CJ. C.S. 17 Becker. A. C. P. 102. 220. 6.115. [6. 115.: 19. 357. 18 Fridau. A. C. P. 83. 23. 27 Semenoff. A. C. Phys. (4) SPECIFIC GRA VITY TABLES. 139 Boiling Melting Name~. Formula. Specific Gravity. BPoilintg Meltin Acetic acid. C2 H4 02. I.O630, 16.~ 22~5. 2 (( 16.~ u (3 ~, I 14.0 4 1~ (( it 120.~ 5 (( (( I.0622. I I9.0 6 tO (C I.o635, 15.0 7 cc cc S. (( I.IOO, 8~5.') 8 (( c( 1. (( I.o65o, I3.0~ 9 (( ( ((0 120.0 10 (( (( I.o8o5, o.t II73 11 ( (( (( I.o6I95, I7.0 760 m. m. 12 ( I.o635, IO.~ II6.~ I7.0 13 c( c( I (( I.o607, 15.0 14.o563. 15 I ( 0I.o565. 1 55. 16 (( (( ( I1.0514, 20,0 I18.0 17 Propionic acid. C3 H6 02. I40.0 18 (( I42. 19 (i.oi6, 0.0 I4I6. 20 (( (( ((.99II, 25~2. 760 m. m. 21 (( ((,(.9963, 20.0 I40. 22 C((.992, 18.~ I39.0 23 Butyric ff C4 H8 02..967 5, 25.0 2 0.s (( *.963, 15. 164.0 25 (( (( I64. 26 (( (( I.98862, o.~ I57.0 27 n (( ('.9739, 1 5- m. of 2. 760 m. m. 28 (( (. (C.98165, o.0 163.0 29 C( (( ((.973, 7.0 156.0 30 0 (( ".9673, 15.0 31 (( (( ((.96IO, 20.0 I62.0 32 (( (( CC.9850, 13-5- 165.- -I 2.Ors.-I4.0 AUTHORITIES. 1 Mollerat. A. C. Phys. (1). 10 J Kopp. 13. 22Linnernann. 21.433. 68. 88. 11 Kopp. 13. 23 Chevreul. See 13. 2 L6witz. Watts' Dictionary. 12 Delffs. 16. 24 Pelouze & Gelis. P. A. 59. 3 Mitscherlich. | See 13. 13 Mendelejeff. 13. 7. 625. 4 Dumas. 14 Roscoe. C. S. J. 15. 270. 25 Person. 1. 91. 5Sebille-Auger. Watts' Dic- 15 Roscoe. C. S. J. 15. 270. 26 Kopp. 13. tionary. 16 Landolt. P. A. 117. 353. 27 Kopp. 13. 6 Mohr. A. C. P. 31. 277. 17 Dumas, Malaguti and Le- 2s Pierre. 15. 7 r Persoz. Watts' Dic- blanc. 1. 551. 29 Delffs. 16. I tionary. 18 Limpricht & Uslar. 8. 508. 30 Mendelejeff. 13. 7. 8 Persoz. Watts' Dic- 194 Kopp. 18. 31 Landolt. P. A. 117. 353. t tionary. 20 I(Kopp. 18. 32 Bulk. A. C. P. 139. 62. 9 Person. 1. 91. 21 Landolt. P. A. 117. 353. 140 SPECIFIC GRA VITY TABLES. Gravity. Melting Name. Formula. Specific Gravity. Boint. Point Point. Point. Butyric acid. iso. C4 H8 02..9598, o.0 I5325 (2 I, (C.9208, 50.~ to 3 ( s acid o. 1 8965:, I0'0~ 154.5~ 4 Valerianic acid. C5 Hlo 02- *941, I4.~ 5 (C (C C.932, 28.0 6 < ((.944, 10.'7 0 (( ((.930, 12?58 (.937, I65.' I75.0 9. (( I75. 10 (( (C ".9403, I5.0 I75.0 (11 (( ((.9 555, 7508. 12 (C C(.9378, I9.6. 763 m. (13 ( (C.935, I 5. I7405. 14 ( ((.95 58, I 5.0 15 C( (C CC.9313, 20.0 I74.0 16 -9 ((.9577, ~'0 0 17 -C C" ((.9415, 20.~ I85.0 18 ( (. 9284, 4~0- 736 m.m. 19o( ((c.9034, 99: 3. J 20 CaproiC " C6 H12 02..922, 26.0 21.93I, I5. ~ 202 -209.O 22 (( (( 22 C198.0 23 C 198.0 24 CC.9252, 20.0 I99.o 25 CC.925, 27.0 I87~-I98.0 26 ((0 zs26 (C.9449, 0.~ 20425 27 (0.9294, 20. 0 to 28 C.9I72, 40.0 205.0 29 CC.8947, 99I.J 738.5 m. m. 30 Ocnanthylic acid. C7 H14 02. 212.0 31'.9167, 24.0 2i8.~ (?) 32 C *.9179, i8.0) 2 33 (( (.9 I 7 5, 20.0 219. 33.. AUTHORITIES. 1 Morkowiikoff. A. C.P. 12Kopp. 18. 23 Wurtz. 10. 351 2 138. 368. 13 Delffs. 16. 24 Landolt. P. A. 117. 353. 2 Morkownikoff. A. C. P. 14 Mendelejeff. 13. 7. 25 Sticht. 21. 522. 138. 368. [138. 368. 15 Landolt. P. A. 117. 353. 26 f Lieben & Rossi. A. C. P. 3 Morkownikoff. A.C.P. 16 Lieben & Rossi. A. C. P. 159. 70. [159. 70. 4 Chevreul. 159. 58. [159.58. 27 Lieben & Rossi. A. C. P. 5 Chevreul. 17 Lieben & Rossi. A. C. P. 28 Lieben & Rossi. A. C. P. 6 Trommsdorf. A. C. P. 6.176. 18 Lieben & Rossi. A. C. P. 159. 70. [159. 70. 7 Trautwein. [267. 159.58. [159.58. 29 Lieben & Rossi. A. C. P. 8 Dumas & Stas. J. F. P. 21. 19 L Lieben & Rossi. A. C. P. 30 Strecker. 9 Person. 1. 91. 20 Chevreul. 31 Stideler. 10. 360. 10 Person ne. 7. 653. 21 Fehling. A. C. P. 53. 406. 32 f Landolt. P. A. 117. 353. 11 Kopp. 18. 2 Brazier & Gossleth. 3.398. 33 Landolt. P. A. 117. 353. SPECIFIC GRAVITY TABLES. 141 Name. Formula. Specific Gravity. Boiling Melting Name. Formul. Point. Point. Caprylic acid. C8 H16 02..91 I, 20.0 2360-240.~ I4~ —I5.0 2 ( U( (.*905, 21.0 238.~ 5.0 rs. 3.0 3 0 (1 (..901, 18.0 13.0 rs. 9.0 4Pelargonic C H18 02. 260.0 10.0 5 (( (( ( 903, 2 I. 255.- I8.~ rs. 13.0 6,, e (( 2480~-250.~ 7.0 s. 0.0 7 Rutylic (( C1O H120 2 30.0 8 (( (( (C 27~2. 9 ct s 1..930, 37.0 264.0 29'5. s. 28.0 10 Lauric (( C12 H124 02. 420-43. 11 (( ( (( 43.0 12 (( (( (.883, 20.0 s. 420-43.0 13, (( (( 43?8. 14 (( (( ( 45.0 15 4306. <16 ( (( I (( I I 1 4305' 17 Myristic ( C14 H28 02. 5308. 18 (C (( i (( I I i 5308. 19 ( (( (( 53.0 20 Benomargaric acid. C15 H30 02 520-53.0 21 Isocetic 55. 22 Cetic 53~?5 23 Palmitic ( C16 H32 02. 61.~ S. 59.0 24 62.0 25 (( CC 62.0 26 Margaric C17 IH34 02. 52~3. s. 50"5. 27 (1, (C C (( I I ( 59?9. 28 ( (( 60.0 29 Stearic C18 H36 03. I.01, o. 30 CC ".854. 1. 31 C, o (( 68. s. 6508. 32 (C (( (,,, 690-69?2. 33,, (( (C 6902. 34 (( (( I a. I.OO, 9.0 70.~ AUTHORITIES. 1 Fehling. A. C. P. 53. 401. 13 Schlippe. A. C. P. 105. 14. 24 Heintz. 7. 461. 2 Perrot. 10. 353. 14 Miiller. J. F. P. 58. 470. 25 Schlippe. 11. 303. 3 Fischer. A. C. P. 118.307. 15 Heintz. 7. 457. 26 Duffy. 5. 511. 4 Cahours. 3. 401. 16 Oudemans. 13. 323. 27 Heintz. 10. 356. 5 Perrot. 10. 353. 17 Heintz. 7. 456. 28 Hanhart. 11. 301. 6 A. Giesecke. Z. F. C. 13.430. 18 Sclllippe. 11. 303. 29 f Saussure. WTatts' Dict. 7 G6rgey. A. C. P. 66. 290. 19 Oudemnans. 13. 323. 30 } Saussure. W5atts' Diet. 8 Rowney. A. C. P. 79. 236. 20 Walter. C. R. 22. 1143. 31 Duffy. 5. 511. 9Fischer. A. C. P. 118. 307. 21 Bouis. 7. 463. 32 Ieintz. 6.446. 10 Marsson. A. C. P. 41. 333. 22 Heintz. 5. 505. 33 Pebal. 7. 445. n Sthamer. A. C. P. 53. 393. 23 Duffy. 5.511. 34Kopp. 8.43. 12 Gorgey. A. C. P. 66. 306. 142 SPECIFIC GRA VITY TABLES. Name. Formula. Specific Gravity. Boiling Point Point. Point. 1 Stearic acid. C18 H36 02. 69.0 A2 rachidic acid. C20 H4o 0~. 75.0 s. 73~5. 3 Benostearic acid. C22 H44 02. 76.0 4 Cerotic ( C27 H54 02. 780-79.0 5 (( (~ (( 8(I(-8 ~ 6 3Melissic C30 H60 02 88'-89.0 4th. ANHYDRIDES OF THE FORMIC SERIES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 7 Acetic anhydride. C4 H5 03- Io073, 20?5- I3705. (( (( (( I37. 12 Propionic C6(( H 03. i65.0 13 (( (( I.OI, I8.O I64~-166.0 14 Butyric (( C8 H14 03..978, I2~5. a. Ig90. 15 Valeric C10 1118 03. 2I5.0 17 ZEnanthylic anhydride C14 H116 03-.9I, I4.0 18 Caprylic (( C16 H30 03' a. 280.0 u Pelargonic ( C,8 H34 O. 5.20 Palmitic 0 C32 6 3 5308. AUTI-IOITIES. 1 Schlippe. 11. 303. 8 Kopp. 17. 14 Gerhardt. 5. 452. 2 Gsslllann. 6. 442. 9 Kopp. 17. 1 Cliozza. J. F. P. 58. 23. 3 Vlcker. 1. 569. 10 Sclllagdelnhauffen. 16 Wlatts' Dictioniary. 4 Brodlie. 1. 702. 11 Boughton. 18. 300. 17 lerba. 7. 4-14. 5 Aaskelvne. 5. 525. 12 Linipricht & v. Uslar. 8.' Chiozza. 5. 454. 6 Brolie. 1. 705. 508. 19 Chiozza. A. C. P. 85. 231. 7 Gerlardt. 5. 451. 3 Lnnernann. 521. 4533. 20 Kekules "Leirbuch." SPECIFIC GRAVITY TABLES. 143 5th. ETHERS OF THE SERIES Cn. H2n. 02. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 1 Methyl formate. C2 H4 02. 360-38.~ ~~~~~2 2 (1 ~~~~~~32?9. 23 (( ( ((.9984, O.~ 4i ( (.9776, 1503. 334. 5 (I (( ((.9766, I6. 760 m. m. 6Ethyl ( C3 H6 02..91I57, 18.0 7.912. 534-. 8 (( (( (( 54.0'9, ( ~ 56.~ 10 8.9394, ~-~0 11 (( ( ((.gI988, I7.Q 13 -*94474, ~ ~ 549.;3 cc I cc.925j44, 150.7.f 6c m. m. 15 I 1 1 54?3..9577, O.~ 1G (( (C 6 (C i ~.93565, o.~ 5279. 17,, (( (( 5 18 (( (( * I.917. 55?5" Propyl.( C4 H8 02.9197, o.~ 20 ( U|.877, 38?5~ 82?5-83.0 21.836, 72.5. 22.88, o. } 2:3 a.876i, 385. ] 8275-83.~ 24J, z (( a.835, 72-:5. 2: Butyl C5 H0lo 2.. a. IOO.~ 26 f( ~.8845, ~o.' 27.850, 34.0 2Y 8.8224, 5998. 8 2(9 a( (( ((.7962, 8304~ 30 Anlyl C6 H112 02..884, 15.0 I I4.~ AUTHORITIES. Liebig. Watts'Dictionary. 14 Andrews. 1. 89. 23 Pierre & Pucllot. A.. 2 Andrews. 1. 89. 15 Pierre. Watts' ictionary. Phys. (4). 22. 288. (n Kopp. 13. 16 Pierre. 15. 24! Pierre & Puchot. A. C. Kopp. 13. 17 Delffs. 7. 26. Phys. (4). 22. 288. 4 Kopp. 13. Lwig. 14.599. 25 Wurtz. 7. 575. 6 GelPie ( Pierre & Puchot. A. C. 7 Liebi,. tSee 17. e12. 660. Phys. (4). 22. 319. M Mlarchand. Watts' Dic- 20 Pierre&Pnchot. Z.F. C. 7 Pierre & Puchot. A. C. tionary. t 12. 660. I Phys. (4). 22. 319. 9 iobereiner. See 13. 21 Pierre & Puchot. Z.F.C. 28 j Pierre & Puclhot. A. C. 10 ( Kopp. See 13. 12. 660. Phys. (4). 22. 319. 11 Kopp. See 13. 221 Pierre (& Puchot. A. C. 29 Pierre & Puchot. A. C. 12 Kopp. 13. Phys. (4). 22. 288. Phys. (4). 22. 319. IS iKopp. 13. 30 Delfts. 7. 26. 144 SPECIFIC GRAVITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 1 Anyl formate. C6 H12 02..8945, 0.0 I 2.0 2 c (C.8743, 21. 3, o.88og, 15.~ 4 Methyl acetate. C3 H6 02..9I9, 22.~0 58.0 5 ( IL 56?2. 6 (1.9328, o. (7 ( (,.9085, 21. 8 (( ".9562, o. 5603. 9 93735, I506. 760 m. m. 10o 55.0 o11 (C.86684, o.~ 590~5 12 Ethyl C C4 HS 02..866, 7.0 7 1. 13 (I.89, 15.~ 14 (C 74.0 Is (. (.9051, o.~ 6 (.9O46, o.~ m. of2. 1 74 17. (( 17 ( o (e.89277, I 57 7 m. Is,(..8926, I 5~9. 19 O (1.9069I, o. ~ 74714. 20 746. 21 o.906, 1795. 22 " " (.903, 17.0 77 5 23 (.932, 20.0 83.0 24 (( (( Purest.,c.9055, I7~5- 780-78~5. 2C LL.8922, I 5.0 74.0 26 L(.898, I 5. 27.903, o.0 720+. 28 Propyl C5 H0 02. a. go.0 29.910, 0. ) 30 (C ( ((.8635, 4295. I03.0 31.8137, 84?6. AUTHORITIES. I Kopp. 17. 12 GThnard ) 23 Gssnlan. 5. 563. 2 Kopp. 17. 13 Liebig. See 13. 24 Marsson. 6. 501. 3i endelejeff. 13. 7. 14 Dumlas & Boullay. P. A. 25 Delffs. 7. 26. 4 Dumas & Peligot. P. A. 12. 430. [427. 26 Mendelejeff. 13. 7. 36.117. 15 Frankenheim. P. A. 72. 27 Pierre & Puchot. A. C. 5 L6wig. See 17. 16 (Kopp. 13. Phys. (4) 22.261. 6 Kopp. See 17. 17 Kopp. 13. 28 Berthelot. WTatts' Dict. 7 Kopp. See 17. 18 Kopp. 13. 29 ( Pierre & Puchot. Z.F. C. 8 Kopp. 13. 19 Pierre. 15.! 12. 660. [12.660. 9 Kopp. 13. 20 Andrews. 1. 89. 30 Pierre& Puchot. Z.F. C. 10 Andrews. 1. 89. 21 Marsson. 4. 514. 31 Pierre & Puchot. Z.F. C. 1 Pierre. 15. 22 Becker. 5. 563. 1 12. 660. SPECIFIC GRAVITY TABLES. 145 Name. Formula. Specific Gravity. Boiling Melting Point. Point. I Propyl acetate. C5 11o 02..910, o.0 2 (( c ((.8627, 42 5. I03.~ 3 ( (( (.828, 846. 4 (( ( (( 913, 0-0 02.~0 5 Butyl acetate. C6 H1112 02.8845, I6.0 I I4. 6 (( ( (( III-II3. 7 (o (I.892, o. II I.~ 8.89096, o.~ 9 (( (.8747, I6.~ 1 I795. l0~8747, I I, 10 ((.83I43, 50. 0 1 ((.ooo, o~~ ) 12 (( Co.8817, 20.0 I2501. 13 Ic.8659, 40 ) 740 14 (( (.9052, o.~ 15 (.8668, 37I. 16 (( ((.8328, 68~9. 6 II6~5. 1 ((0 (( ((.7972, 99.75. 19 Amyl cc C7 H~ 02. I125.0 20,,((.8572' 2I. 3303 21 1 3303. ~20 (( 0~ (( ~ ~.8765, o. } 22.8837, 0.07 22 (((( (((( (( ~8837, o.~ I37~6 23 ((.8692, 151. 24 (( (( (.863, IO.~ I33.0 253(< ( ((.8762, I 5.~ 26 o.8733,J 15. I40.' 2 c7 ( ((.8752, (Two products. 28.8963, o.~ c29 o o c((.8792, 20.~ 14894. 30 cc ((.8645, 40.0 ) 737 m. m 31 (( iso. (c.9222, o.0 I330-I35.0 AUTHORITIES. Pierre & Puchot. A. C. 11 Lieben & Rossi. A. C. P. 19 Cahours. See 17. Phys. (4). 22. 289. 158.137. [158. 137. 20 Kopp. See 17. 7 Early Pierre 1 21chot. A.C. determi2 Pierre & Puchot. A. C. 12 Lieben &; Rossi. A. C. P. 21 Kopp. See 17. nations. Phys. (4). 22. 289. 13 Lieben & Rossi. A. C. P. 22 Kopp. 17. 3 Pierre & Puchot. A. C. 158. 137. 23 Kopp. 17. Phys. (4). 22. 289. 14 Pierre & Puchot. A. C. 24 Delffs. 7. 26. 4 Rossi. A. C. P. 159. 79. Phys. (4). 22. 322. 25 Mendelejeff. 13. 7. 5 Wurtz. 7. 575. 15 Pierre & Puchot. A. C. 26 Schorlemmer. 19. 527. 6 De Luynes. 16. 503. Phys. (4). 22. 322. 27 Schorlemmer. 19. 527. 7 Lieben. 21. 443. 16 Pierre & Puchot. A. C. 28 Lieben & Rossi. A. C. P. 8 F Chapman & Smith. C.S. i Phys. (4). 22. 322. 159. 70. [159. 7G. J. 22.160. [J. 22.160. 17 Pierre & Puchot. A. C. 29 Lieben & Rossi. A. C. P. 9 4 Chapman & Smith. C. S. Phys. (4). 22. 322. 30 i Lieben & Rossi. A. C. P. 10 j Chkapman &Smith. C.S. 18is Pierre & Puchot. A. C. [ 159. 70. i J. 22.160. Phys. (4). 22. 322. 31Wurtz. Z. F. C. 11.490. 146 SPECIFIC GRAVITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. Hexyl acetate. C8 H116 02. I45.~ 2 (( (( ((.8525, 0.~ I40_-I45.0 (( (( ((.8778, o. I 550-I 57.0 4 (( (.83IO, 50.~ 787 m. m. 5 Heptyl C9 H18 02..8868, 1 9. 6 (( ((.8707, I6.5. I78~-180.~ 7 ( ((.8605, I6. I80o~-I82.0 8 (( (( ( I 80.~ 9 Octyl (( C10 H, 02. 193.0 10 ( (( ( I90-I92. 11 I 90~1O-I95.0 12 (( (200 -205. 13 (( ((.87I7, 16.0 2060-208.0 14 NOllyl (( C11 H.2 0,. 2080-2 I 2.0 15 Cetvl (( Cs H3602..858, 20.0 2220-225.0 1895. 16 Ethyl propionate. C5 H11 0. IOI0.0 c17 C.923I, 0.0 ) 1 (( (( (.8949, 263. 32-98. 190.9137, 0.0 ) 20 (.863, 451- I00.0 21 (( (( ((.8I7, 83.0 760 m. m. 22.9139, 0.0 } 2 (( (( (( 9I39, 23 (( (( ((.8625, 45?1. I00.~ 24 (( ((.8i6, 83.0 2 Propyl " C6 H12 02.903, 0. 26 (( ((.857, 51927. 124~3. 27 ( c 795, 100o6. 1 76 m. m. *280 (( ( ((.785, I08~34. 29.9022, 0o.O 30 (( ((.8498, 51727. I23~5-I25.0 31 ( ((.7944, Ioo06. AUTIHORITIES. 1 Pelouze Cahours. 16.527. 14 Pelouze & Cahours. 24 Pierre & Puchot. A. C. 2 Buff. 21. 336. 15 Dollfus. 17. 518. Phys. (4). 22. 351. 16. 522. [16.522. 17 f Kopp. 18. 12.628. [12.628. 4 Wlanklyn & Erlenmeyer. 18 il Kopp. 18. 26 Pierre & Puchot. Z. F. C. Scllorlemmer. ) A. C. P. 19 (Pierre & Puchot. Z. F. C. 27 Pierre & Puchot. Z. F.C. 6 Sclorlemmier. 136. 271. I 12. 660. [12.660. 12. 628. [12. G28. 7 Schorlenlner. ) Threeproducts. 20 - Pierre & Puchot. Z. F.C. 28 Pierre & Puchot. Z. F. C. 8 Bouis & Carlet. A. C. P. 21 i Pierre & Puchot. Z. F. C. 29 Pierre & Puchot. A. C. 124. 352. [ 12. 660. Phys. (4). 22. 293. 9 Bouis. 8. 526. 22 ( Pierre & Puchot. A. C. 30 Pierre & Puchot. A. C. 16 Dachauer. 11. 305. Phys. (4). 22. 351. 1Phs. (4). 22. 293. 11 Pelouze & Cahours. 16.529. 23 Pierre & Puchot. A. C. 31 Pierre & Puchot.. C. 12 Schorlemmer. 22. 368. L Phys. (4). 22. 351. L Phys. (4). 22. 29). 13 Zincke. 22. 370. SPECIFIC GRAVITY TABLES. 147 Name. Formula. Specific Gravity. Boiling Melting Point. Point. Propyl propionate. C6 H2 02..7839, 108~34. 2 But;yl (( I(C7 H4 02..8934, o.~ 0 13 (.8445, 49'2. 1 I3507. (4( ( (( *~.7903, OO' 5.1 764 m. m. ~~5 <(.~~~~~.7705, I I65. ) 6 (( (( (1.8926, o.0 ] C7 ((.8437, 4972.! I3507. 8,.7896, I00? I 55. 9 (C 9 ((.7698, II6~5.. 10 AInyl C8 H16 02. I55.0 1 Methyl butyrate. C5 H1O 02. 93.0 12,, (( ((.92098, o.0 959.' 13 0(.9045, 15750 760 m. m. 14 (C (( (( 1.02928, 0.~ 1027 1. 15 (1 (( ( 93-. 16 ((.9091, 0. 17 ((.8793, 3073. 18 Ethyl C6 H1112 02. I i0.~ 19 (( 0. 20 (C.90412, 0.0 I 4~8. 21.89065, 13-i 760 m. m. 22 (( ((.90193, 0o. 1I 9. 23 ~( (( (( I I3-~ 23 I(C 3.0 24.8894, 15.0 =2 Propyl C7 H14 02. a. I30.0 26 ((.888, o.~ ] 27 ( ( ( 841, 47?25. I37.25. 28 ~.785, 100o25. 765 m m. 29 (C C( o( *~.753, I28275. J 30 CC.8872, o.0 31 (( (.8402, 47?24. 135.25 AUTHORITTES. 2 Pierre & Puchot. A. C. 9 Pierre & Puchot. A. C. 22 Pierre. 15. Phys. (4). 22. 293. Phys. (4). 22. 324. 23 Delffs. 7. 26. 2 Pierre&Puchot. Z.F. C. I~Wrightson. 6. 439. 24 Mendelejeff. 13. 7. 12. 660. [12.660. 11Favre & Silbermann. See 25 Berthelot. See 17. Pierre Puot. Z. C. 17. 26 Pierre & Puehot. Z. F. C. Pierre & Puchot. Z. F. C. 12 Kopp. 13. 12. 660. [12. 660. | 12. 660. [12. 660. 13 Kopp. 13. 27 Pierre & Puchot. Z. F.C. I Pierre & Puchot. Z. F.C. 14 Pierre, 15. 28 Pierre & Pucllhot. Z. F. C, 6 Pierre & Puchot. A.C. 15Delffs. 7.26. 12. 660. [12. 660. Phys. (4). 22. 324. 16 f Kopp. 1S. 29 (Pierre & Puchot. Z. F. C 7 Pierre & Puchot. A. C. 17 [ Kopp. 18. 30 (Pierre & Puchot. A. C. Phys. (4). 22. 324. 18 Pelouze. Phys. (4). 22.295. 8 Pierre Puchot. A. C. 19 Lerch. See 17. 31 Pierre & Puchot. A. C. Phys. (4). 22. 324. 20 1 Kopp. 13. Phys. (4). 22. 295. 21 Kopp. 13. 148 SPECIFIC GRA VITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Point. Point.'Propyl butyrate. C7 H14 02-.7842, 100.25-. 2 (( (( ((.7525, I28.75-J 3 (( (( iso. ((.8787, 0. I28.0 4 (( (( (( ((.8652, I3- 0 755 m. m. 6 Butyl C8 H16 02..872, 0.0 7,( (( ( 8245, I~8. J 7s89m. m. 86 (( (( (( *.8245, 5128.' 7.776, 9926. 149.5. 11 (( 0 ((.8579, 40.0 735.7 m. m. 12.8719, 0.0 13 ( (.8238, 5028. I49.5. 4 ( (.7753, 9928. (( 0 (( i(.7439, I2803. J 16 AY1 (( C9 H8 02-.8683, 15.0 17 (.852, 5.0 176.~ 18 ((.8769, 0.~ 19 ((.8264, 5504. I70.3. 20 (( (( ((.7839, 100.2. 760 m. m. 21 (( (( ((.7446, I395. 22 Cetyl (( C20 H40 02..856, 20.0 1. 2600-270.0 20.0 rs. 15.0 23 lethyl valerate. C6 1,12 02. 8960, o.0 I 140-I15 CC (C c,.88o6, i6.0 2 (5 (.901525, 0. ) 26 (( 8 0.88687, I15. I I62. 27 ( (.88662, I53. ) 760 m. m. 28, (( (( C(.9005, 0. 29 (( (.858i, 415.- 17 I 7~25. 30 ((.8343, 643. 31 (( 7945, 100. I. AUTHORITIES. 1 Pierre & Puchot. A. C. 12 Pierre & Puchot. A. C. 21 Pierre & Puellot. A. C. Phys. (4). 22. 295. Phys. (4). 22. 326. N Phys. (4). 22. 343. 2 Pierre & Puchot. A. C. 13 Pierre & Puchot. A. C. 22 Dollfus. 17. 518. Phys. (4). 22. 295. Phys. (4). 22. 326. 23 Kopp. See 17. 3 Silva. Z. F. C. 12.508. 14 Pierre & Puchot. A. C. 24 Kopp. See 17. 4l Silva. Z. F. C. 12. 508. Phys. (4). 22. 326. 25 Kopp. 13. 5'(Pierre&Puchot. Z. F. C. 15 Pierre& Puchot. A. C. 26 Kopp. 13. 12. 628. [12. 628. Phys. (4). 22. 326. 27 Kopp. 13. 6 Pierre & Puchot. Z. F. C. 16 lendelejeff. 13. 7. 28 Pierre & Puchot. A. C. 7 Pierre & Puchot. Z. F. C. 17 Delffs. 7.26. Phys. (4). 22. 349. 12. 628. [12. 628. 18 (Pierre & Puchot. A. C. 29 Pierre & Puchot. A. C. 8 Pierre & Puchot. Z. F. C. Phys. (4). 22. 343. Phys. (4). 22. 349. 9 Lieben & Rossi. A. C.P. 19 Pierre& Puchot. A. C. 30 Pierre & Puchot. A. C. 158. 137. SPECIFIC GRA VITY TABLES. 149 Name. Formula. Specific Gravity. Boiing Melting Point. Point. IEthyl valerate. C7 H14 02..894, I3-~ I335.2.869, 14.0 1330-134.0 ~3 (( (( ~~~~((.8829, o.' o a4 (( (( (.8659, I8.o;f 131.886, o.~ 6.832, 557 I355-.7843, 99 63. 760 8,.7 582, I22 5. J 9Propyl ( C8 HI6 02..887, 0.~ 10o *8395 5O8- | 157.0 ~~~~11.-~~79 5, 00~I5. - 76I m. m. 12 776, II3 713 (( 1.8862, o.' I'4.8387, 50-8. I57.0 15 0 ( (((.-7906, oo001 516 (. I " *7755, II 3~7. 7 (( (( iso. (.8702, 0.0 I42.0 18 (( ((.8538, 17. 0 756 m. m. 19 Butyl C(( H18 2-..8884, o.~ I o e20.8438, 497.. 1 734. 21 ((.7966 Io00. 760 m. m. 22 (( (( ((.7428, 155'8. J 2' Anlyl (( C 1H2002- a. I96.0 2 (( ((.(( 8793, 0.0 I ~ 23 (1 0 ((.8645, I77. 8 26 ( ( ((.8596, 15-. 27 (( ((..874, o.0~ 28 ((.832, 50I67.0 190.0 29 ((.787, 00.~ 30 ( (740, I495 11 Octyl C13 H26 02..8624, 16.0 2490-2 5 I.0 AUTHORITIES. 1 Otto. A. C. P. 25. 62. 11 Pierre & Puchot. Z. F. C. 20 Pierre & Puchot. A. C. 2 Berthelot. 7. 441. 12. 660. [12.660. lPhys. (4). 22. 330. 3 ( Kopp. 17. 12 ( Pierre & Puchot. Z. F. C. 21 Pierre & Puclhot. A. C. 22Kopp. 17. 13 CPierre & Puchot. A. C. Plys. (4). 22. 330. 5 Pierre & Puchot. A. C. Phys. (4). 22. 297. 22 Pierre & Puchot. A. C. Phys. (4). 22. 353. 14 Pierre & Puchot. A. C. L Pllys. (4). 22.330. 6 Pierre & Puchot. A. C. Phys. (4). 22. 297. 23 Balard. See 17. Phys. (4). 22. 353. 15 Pierre & Puchot. A. C. 24 Kopp. 17. 7 Pierre & Puchot. A. C. Phys. (4). 22.297. 25 Kopp. 17. Phys. (4). 22. 353. 16 Pierre & Puchot. A. C. 26 Mendelejeff. 13. 7. 8 Pierre & Puchot. A. C. Phys. (4). 22. 297. 27 Pierre & Puchlot. Z. F. C. Phys. (4). 22. 353. 1 Silva. Z. F. C. 12. 508. 28. Also, A 9 ( Pierre & Puchot. Z. F.. 18 Silva. Z. F. C. 12.508. 29 12.628ys. Als 22. 346. 1 12. 660. [12. 660. 19 Pierre & Puchot. A. C. 30 ys. (4). 22.34 (.Pierre & Puchlot. Z. F. C. Phys. (4). 22. 330. 31 Ziicke. 22.371. 150 SPECIFIC GRAVITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Nm.Point. Point.'Cetyl valerate. C21 H42 02'.852, 20.0 1. 2802 -2 9m. 25.~ rs. 20.~ 202 m. m. 2 Methyl caproate. C7 H14 02..8977, I8. I 50.0 Ethyl C H16 02. I20.0 4 (((.882, I8.0 I62.0 5 Aryl CH H1122 02. 2 I1. [The so-called cenanthic ether of Pelouze and Liebig, (see A. C. P. 19. 241.), is omitted on account of its uncertain character. See Delffs, pelargonic ether.] 6 Methyl caprylate. C9 H1 02..882. 7Ethyl ( C10 H20,02.8738, I5.0 214.0 8 ((.8728, i6.0 2040-206.0 9 Octyl ( C16 1132 02.8625, I6.~ 2970-299.0 10 Ethyl pelargonate. C11H2202.86. 2 60-28.~ "U ", (, (?) ".8725, 1525. 224.0 12 Methyl rutylate. 2230-224.0 13 Ethyl C12 H24 02..862. 14 2430-245.0 13 Ethyl laurate. C14 H12802..86, 20.0 264. s. —IO.0 16 (( ((.867 I, I9.0 269.0 17 Ethyl myristate. C16 H1322..864.1. 18 Methyl palnlitate. C17 H 28.0 S. 22.0 19 Ethyl (( C18 H36 0. 24.2. 20 0 ( 21 2I~5.S. I 8.~ 21 Amyl, C21 H42 02. 135. 22 9.0 2 (( ( (( 23 Miyricyl C46 H92 02 71I5-72.0 24 Methyl stearate. C19 H138 02 38.0 25 Ethyl C20 H40 02. 27.0 26 300-310 27 32.0 28 (( (( 31. AUTHORITIES.'Dollfus. 17. 518. 11 Delffs. 7. 26. 21 Duffy. C. S. J. 5. 314. 2 Fehling. A. C. P. 53. 399. 12Grimm. 22 Berthelot. 6. 503. 3 Lerch. A. C. P. 49. 212. 13 Rowney. 4. 443. 23 Brodie. A. C. P. 71. 144. 4Fehling. A. C. P. 53. 399. 14 Fischer. A. C. P. 118.307. 24 Hanhart. C. R. 47 230. S Brazier & Gossleth. 3.400. 15 G6rgey. 1. 561. 25 Lassaigne. Watts' Dic6 Felhling. A. C. P. 53. 399. 16 Delffs. 7. 26. tionary. 7Fehling. A. C. P. 53.399. 17 Playfair. A. C. P. 37.153. 26 Redtenbacher. A. C. P. 8 Zincke. 22. 373. 18 Berthelot. 6. 502. 35. 51. 9 Zincke. 22. 371. 19 Heintz. 6. 447. 27 Francis. A. C. P. 42. 261. 10 Cahours. 3. 401. 20 Berthelot. 6. 502. 28 Hanhart. C. R. 47. 230. SPECIFIC GRAVITY TABLES. 151 Name. Formula. Specific Gravity. Boiling Melting Point. Point. Ethyl stearate. C20 H4002 33o3. ~~~~~~~~~~~~~~2 ~~~~33?7. 2 (( (( (( 337 (( (( ((3299. 5 myl ((A C23 H46 O2. 2505. 6 ( ( 25.0 (?) 7 Octyl o C6 H1 02 45.0 (?) 8 Cetyl (( C34 H68 02. 55~-60.~ 9 Methyl arachidate. C21 H42 02. 540-54. 5 10 Ethyl ( C2 144 02 55. s. 5 1. 11 Amyl ( C25 H50 02. 4478-45.0 12 Ethyl benostearate. C24 H48 02 480~49.0 13 Ethyl cerotate. C29 H8 02. 60~3. 14Ceryl, C54 H108 02. 82.~ 6th. ALDEHYDES OF THE SERIES C, H2n O. Name. Formula. Specific Gravity. Point. Point B'Poilnt. Point. 15 Acetic aldehyde. C2 4 0..7900, I8.~ 2I~8. 17 (((( *(.79388, 5.6. 2008. 8.80092, 0. 760 m. m. 19 9. (1.80551, 0.0 22.0 20 (( ((.796, 15.~ 23~-28.~ 21 Isom er of aldehyde. (( I.033, 0-~ I I0. 22 Paraldehyde. I230-I 24.0 I 2 23 (( ((.998, I 5. I24.0 I0~5.S. I0.~ 24 Elaldehyde. (( 94.~ 2.0 rs. o.0 25 Propionic aldehyde. C3 H6 0..790, I5.0 550-600 26 (" ((.8284, o.~ 540-63.0 AUTHORITIES. 1 Crowder. 5. 521. 10 G6ssmann. A. C. P. 89. 1. 19 Pierre. 15. 2 Duffy. 5. 511. "1 Caldwell. 9. 492. 20 Guckelberger. 1. 848. 3 Heintz. 5. 517. 12 V61cker. A. C. P. 64. 342. 21 Bauer. 13. 436. 4Pebal. 7.446. 13 Duffy. 5. 511. 22Lieben. 13.310. 5Duffy. 5. 514. 14 Watts' Dictionary. 23 Kekul6 & Zincke. Z. F. C. 6 Hanhart. C. R. 47.230. 15 Liebig. A. C. P. 14. 132. 13. 560. 7Hanhart. C. R. 47.230. 16 Kopp. 18. 24 Fehling. A. C. P. 27. 319. 8 Berthelot. A. C. Phys. (3). 17 Kopp. 18. 25 GlckelbergeT. 1. 848. 56. 70. 18 (Kopp. 18. 26 Michaelson. 17. 336. 9 Caldwell. 9. 492. 152 SPECIFIC GRAVITY TABLES. Name. Formula. Specific Gravity. Boiling Melting 1 Propionic aldehyde. C3 H6 0..8327, o.0 2 ((.8201, 907. 46.~ 3,(, (,.7906, 3296. 4 ~ ".804, 17.0 49955,( s( n.832, o.0 6, 9 o((.8192, 907. 46.~ I'7 (( (1.7898, 3206. 8 Butyric cc C4 H8 0..80, 5.0 680-73.0 "9 ((, ((.834I, o.O 730-77.0 10.8226, o.0 11,, (( -.79I9, 27?75. i 62.0 12.7638, 504 )'13. a. 75. 14 (( 86i8, o.0 ),, (15 " 1~.79I I, 27075. 62.0 16.763, 5004. 4 11 Valeric ((e C5 H10 0..8 I 8. 18 (.820, 22.0 a. I o.0 19 cc.8o00, 20.0 a. 9o.0 20 ((.8224, 0.0 928. 21 cc cc.8o57, I774. 9208. 22 (( (( ((.822, O.~ 23.779' 4304 9295. 24 (( (( 749, 7 I 9. 5 25 (( c( o.8209, o0. 26.778, 4394. 27,, (. 7485, 7 19. 28 Hexyl ( p C6 H12 0..8298, o.0 I27.0 29.7846, 50.0 76I.2 m. m. AUTHORITIES. I Pierre & Puchot. Z. F. C. 11 Pierre & Puchot. Z. F. C. 20 Kopp. 17. 13. 255. [13. 255. 13. 255. 21 Kopp. 17. 2 Pierre & Puchot. Z. F. C. 12 Pierre & Puchot. Z. F. C. 22 Pierre & Puchot. Z. F. C. 3 Pierre & Puchot. Z. F. C. L 13 255. 13. 255. [13. 255. L 13. 255. 13 Lieben & Rossi. A. C. P. 23 Pierre & Puchot. Z. F. C'. 4Rossi. A. C. P. 159. 79. 158. 137. 24 J Pierre & Puchot. A. C. P. 5 (Pierre & Puchot. A. C. 14 Pierre & Puchot. A. C. 13. 255. Phys. (4). 22. 298. Phys. (4). 22. 332. 25 Pierre & Puchot. A. C. 6 Pierre & Puchot. A. C. 15 Pierre & Puchot. A. C. Phys. (4). 22. 340. Phys. (4). 22. 298. Phys. (4). 22. 332. 26 Pierre& Puchot. A. C. 7 Pierre & Puchot. A. C. 16 Pierre & Puchot. A. C. Phys. (4). 22. 340. 1Phys. (4). 22. 298. Phys. (4). 22. 332. 27 Pierre & Puchot. A. C. 8 Guckelberrer. 1. 849. 17 Trautwein. See 17. L Phys. (4). 22. 340. 9Miclaelson. 17. 336. 18 Chancel. J. F. P. 36. 447. 28 Wanklyn & Erlenmeyer. 10 Pierre & Puchot. Z. F. C. 19 Personne. 7. 654. 16.522. [16. 522. 13. 255. 29 Wanklyn & Erlennleyer. SPECIFIC GRAVITY TABLES. 153 Name. Formula. Specific Gravity. Boiling Melting Point. Point.'Isomer of hexyl aildehyde. C6 H12 0..842. I5. I8o0~-I85.0 2(Enanthol. C7 H14 0..827I, 7.0 I55~-I58.0 3 I55~-I56.0 4 (( I55-0 5 ( I5I-I52.0 6.827, 17.0 I55~-I56.~ 7 Isomer of oenanthol..835, I4.0 I6I~-I64.0 8 Octyl aldehyde. C8 H16 0..8i8, 19.0 I7I.0 9.820. 178.0 10 Euodyl ( * Cl H12 0..8497, I 5.0 2I3. S. 7.0 11 Laurlyl (( C22 H24 0. 232.0!2 Cetyl 132 012 Cetyl (J C16 13 460-47.0 13 Palmityl (( 52.0 7. ACETONES. GENERAL FORMULA Cn H2, O. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 14 Acetone. C3 H6 0. 56.0 15 ((.7921, I8.0 55.6. (16 1( s.8I44, o.~ 56~3. 17 ( ( 79945, I35* 760 m. m. 18 ( ( 550-56.0 19 ((..790, I5.0 560-57.0 20 Methyl acetone. C4 H8 0..838, 19.0 75~-7721 ( ( ((.8125, I3.0 81.0 22, ((.824, o.o 79?5-8.~0 23 (( o( (C.8063. 15 3- 770-79.0 24 Acetyl ethyl. (775-78.0 25 Butyral. (.82I, 22.0 95.0 26 Propione. C5 Hi 0. 1 10.0 27 ( (( I I I. AUTHORITIES. 1 Fittig. 13. 319. 11 Kekule's "Lehrbuch." 20 Fittig. 12. 341. 2 Bussy. J. F. P. 37. 92. 12 Dollfus. 17. 518. 21 Frankland & Duppa. 18. 3 Williamson. 1. 565. 14 Dumas. Watts' Dictionary. 309. 4Tilley. 1. 566. 15 Liebig. See 13. 22 Popoff. 20. 399. 5 Stideler. 16 (Kopp. 13. 23 Grimm. Z. F. C. 14. 114. 6 Bouis. 8. 524. 17, Kopp. 13. 24 Freund. 13. 312. 7Fittig. 13. 319.'lFreund. 13. 313. 25 Chancel. C(. R. 19 1440. 8 Bouis. 8. 524. 19 Linnenmann. A. C. P. 143. 26 Limpricht&v. Uslar. 8.51.. 9 Limpricht. A. C. P. 93. 242. 349. 27 Friedel. 10 Williams. 11. 443. * Probably an acetone. Compare with methyl caprinal. 11 154 SPECITFiC GRAVITY TABLES. BoilingF Melting Name. Formula. Specific Gravity. Point. Point.'Propione. C5 H 0 0..8Ii, II.5. IOI.0 2 (( 8I45, IOI ((.8145, o.' 3 1.8o i5, 15? 101. 4 (( I000-IOI10 5 (( ((.8078, I8~5. 99~-IoI.~ 6 Methyl butyral. (.827, o0.~ I I.0 7 Ethyl acetone..842, I 9.0 900-95. (8 (.8132, i3.0 IOI0 9 (.8040, 22.0 I:0 Dimethyl acetone..8099, I3,0 9335. 11 Ethyl butyral. C6 I-12 0..833, o.~ 128.~ 12 Isopropaceton!e..8I892, 0. I I4.0 1_3 Methyl valeral. ( I20.0'- Butyrone. C7 114 0..830. I44.~ 156 I45.0 16 Diethyl acetone. (.8I71, 22.0 I37-5-I39.0 17 Methyl amyl acetone.,.828-.829. I44.0 18 Methyl butyrone. C8 H16 0..827, i6.~ 180.0'9 Methyl cenanthol..817, 23.0 I71 -I7I~5. 20 Valerone. C9 H18 0. I64~-I66.~ 2' Caprone. C1 1122 0. I65.0 22 Butyl butyrone. ((.828, 20.0 222.0 S. I2.0 23 Methyl caprinol.* 8295, 775.. 5 6. 24 ".828 I7, 8'7. 224. s. 5~ to 6.0 25 (( (( C..8268, 2035. 2250-226.0 I5.0 rs. 6.~ 26 IEnanthone. C13 H26 O..825, 30.0 264.0 30.~rs.2905. 27 Caprylone. C15 110 0. 278. 40.~ s. 38.' 28 Caprinone. C 38 0 58.? s. 56.0 2' Laurone. C23 H46 O. 66.0 30 Myristone. C27 154 0. 7 5 31 Palmitone. C31 H62 0. 84.0 s. 80.~ AUTHORITIES. 1 Geuther. 20. 455. u Friedel. 11. 295. 21 Brazier & Gossletl. 3. 399. 2 ( Chapman & Smith. 20. 12 Frankland & Duppa. 20. 22 Linpricht. 11. 296. 453. [453. 395. 23 Gorup-Besallez&rinl. 3 Chapman & Smith. 20. 13 Williamson. A. C. P. 81.86. Z.F. C. 13. 290. 4 Freund. 13. 313. 14 Chancel. A. C. Phys. (3). 24 Gorup-Besanez&Grimnm. 5 Grimm. Z. F. C. 14.174. 12. 146. Z m. F. C. 13. 290. 6 Friedel. 11.295. 15 Friedel. 11. 295. [306. 25 A. Giesecke. Z. F. C. 13. 428. 7 Fittig. 12. 341. 16 Frankland & Duppa. 18. 26v.Uslar&Seekamp. 11.299. s ( Frankland & Duppa. 18. 17Popoff. 18. 314. 27 Guckelberger. 2. 340. 307. [307. 18 Limpricht. 11. 296. 28 Grinmm. A. C. P. 157. 271. s9 Frankland & Duppa. 18. 19 Sttideler. 10. 361. 29 Overbeck. 5. 502.'0Frankland & Duppa. 18. 20 Ebersbach. A. C. P. 106. 0 Overbeck. 5. 503. 309. 268. 231 Maskelyne. C. S. J. 8. 11. * Compare Methyl caprinol with Euodyl aldehyde. SPECIFIC GRAVITY TABLES. 155 Name. Formula. Specific Gravity. Boiling Melting Point. Point. 1 Stearone. C35 H70 0. 86.0 2 ( 87~8. 8th. OXIDES OF THE ETHYLENE SERIES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 3Ethylene oxide. C2 H4 0..8945, 0o. I3~5. 4Propylene (( C3 H6 0..859, 0.~ 35-0 Amylene (( C5 H10 0..824, o.O 95-. 6 Octylene (( C8 H16 O..83I, 15.~ I45~0' Diamylene (( C, H20 0. I700-I80.~ 8 ( ( ( ".9402, 0.~ I 80~-I 90. 9 Dioxethylene. C4 H8 02' 10 Ethylene ethylidene I.0482, 0. I 02.0 9.0 oxide. (( 1.0002, 0.0 8205. 9th. GLYCOLS. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 11 Ethylene glycol. C2 H6 02. I.125, 0o.~0 I97~-I97*512 ( ( (( I93.0 13 Propylene ( C3 H1 03. I.05I, 0.~ I88.0 14 (( (( I.038, 23.0 1' Butylene C(4 HO 02. I.o48, o.~ I83~-I84.0 16 Amylene (( C5 H12 O2-.987, o.0 I77.0 "E HexyTlene ( C6 H14 02-..9669, o.0 207.0 18 Oetylene (( C8 H118 0. 932, 0.0 2350-240.0 19 ((.920, 29. AUTHORITIES. I Bussv. A. C. P. 9. 270. 8 Schneider. A. C. P. 157.221. 13 ( Wurtz. 10. 464. 2 Hleintz. P. A. 94. 272. 9 Wurtz. 15. 423. 14 Wurtz. 10. 464. 3 Wurtz. 16. 486. 10 Wurtz. 14. 656. 15Wurtz. 12. 499. 40ser. 13. 448. 11 Wurtz. A. C. Phys. (3). 16 Wurtz. 11.424. 5 Bauer. 13.451. 55. 410. 17 Wurtz. 17. 516. GDe Clermont. Z. F. C. 13. 12 Atkinson. P. M. (4). 16. 1 De Clermont. 17. 517. 411. 437. 19 ( De Clermont. 17. 517. 7 Bauer. 15. 451. 156 SPECIFIC GRAVITY TABLES. 10th. MISCELLANEOUS COMPOUNDS OF THE ETHYLENE SERIES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 1 Ethylene diethylate. C6 H1114 02. 7993, ~.~ I23?5~ 2Amylene ethylate. C7 H16 0..759, 21.0 I202-I03.~ [Compare the above with ethyl amyl oxide.] 3 Amylene hydrate. C5 H120..829, o. Io5~-I08.0 4Diamylene, C0 H22 0..909, 0o- i63.~ 5Octylene C H18 O.' 811, 174 78 56 O.793, 23.0- [Compare amylene and octylene hydrates with amyl and octyl alcohols.] 7 Diethylene alcohol. C4 1110 03 245.0 98 < (( (( I.32, 0.0 a. 250.0 9 Triethylene o C6 H14 04. 285~-290.~ lo < 0 (( I. 138. a. 290.~ a1 Tetrethylene C8 H18 05 230? 25 mm. 12 Pentethylene C1o H22 06. 281? 25 m.m. 13 Hexethylene u C12 H26 07. 325? 25 m.m. 14 Ethylene monacetate. C4 HI 03. I8 I-I82.~ 15 diacetate. C6 H10 04. 1.128, o. I86~-I 87. 16 Diethylene'( C8 H14 05. 2450-255.0 17 Triethylene C10 H18 06. a. 300.0 i8 Tetrethylene C12 H22 07. 3200+. 19 Ethylene monobutyrate C6 H12 03. a. 220.0 20 dibutyrate. C10 H18 04 1.024, o.~ 239~-24I.~ 21 monovalerate. C7 H14 03. a. 240.0 22 divalerate. C12 1122 04 a. 255.0 23 aceto-butyrate. C8 H14 04. 208~-2I 5.0 24 ( aceto-valerate. C9 H16 04. a. 230.0 25 distearate. C38 H74 04. 76.~ 26 Propylene diacetate. C7 H2 04. I.09,.0 186.0 AUTHORITIES. 1Wurtz. 11. 423. 9Loureneo. 13. 443. 1s Wurtz. 16.489. 2 Reboul & Truchot. 20.582, l0 Wurtz. 16. 489. 19 Lourenqo. 13. 438. 3 Wurtz. A. C. P. 125. 114. 11 Lourenqo. 13. 443. 20 Wurtz. 12.486. 4 Wurtz. 16. 516. 12 Lourenqo. 13. 443. 21 Lourenlo. 13. 438. (5 De Clermont. A. C. P. 13 Lourengo. 13. 443. [435. 22 Lourengo. 13. 438. 149. 38. [149. 38. 14 Atkinson. P. M. (4). 16. 23 Simpson. 12.488. 6 De Clermont. A. C. P. s15 Wurtz. 12.485. 24Lourengo. 13. 438. 7 Lourengo. 13. 443. 16 Wurtz. 16.489.'5 Wurtz. 12. 486. 8s Wurtz. 16. 489.'7 AVurtz. 16. 489. 26 Wurtz. 10. 464. SPECIFIC GRA VITY TABLES. 157 Name. Formula. Specific Boiling Melting Gravity. Point. Point.'Butylene diacetate. C8 1114 04. a. 200.0 2Hexylene (( C0l H18 04. I.014, 0.0 2I5~-220.~ 3 Octylene ( C12 H22 04. 2400-245.~0 4 c(.. 2450-250.0 5 Butylene acetate. C6 H12 02. I I IO-I I3.0 6 Octylene acetate. CO H20 0.822, 0.0 I63 7I~~~~~~ (, (,,.803, 26.0. 63I8O. [Compare the two last with the acetates of butyl and octyl.] 11th. ACIDS. LACTIC AND OXALIC SERIES. Name. Formula. Specific Boiling Melting Gravity. Point. Point. 8 Glycollic acid. C2 14 03 780-79.0 9 Lactic ( C3 H160. 1.215, IO. 10 Leucic C6 112 02. 73.0 11 Oxalic acid. Sublimed. C2 H2 04. 2.00, 09. 12 (( (( Crystallized. CH204.2 H20 1I.507. 13 ((.622. 14 I629. 6 5 1.63, 9., 16 V O a. 98.0 17 Succinic acid. C4 H6 04. -.55. 18, (( Sublimed. I. 529, 9.0 19. ((Crystallized. (C 1.552, 9-0 20 ( 235.0 d. I80.~ 21 Pyrotartaric acid. C5 H8 04. I90+. I00.~0+. 22 o o I IO0~-I I25. 23 ( I I I ~- I 2.~ 24 Adipic ( C6 H110 04 I45. 25 Pimelic C7 H12 04-. I34.0 AUTHORITIES. 1 Wurtz. 12. 499. 0 Waage. A. C. P. 118. 295. 19Husemnann. 26. 2 Wurtz. 17. 516. n' Housemann. 26. 20 Watts' Dictionary. 3 Wurtz. 16. 509. 12 Richter. See ll. 2 Arpe. A. C. P. 66. 73. 4De Clermont. 17. 517. 13 Playfair and Joule. 11. 22 Kekul6. A. C. P. 1st. supp. 5 De Luynes. 17. 501. 14 Buignet. 14. 15. vol. 338. 6 De Clermont. 21.. 449. 1 Husemann. 26. 23 Wislicenus. Z. F. C. 13. 7 De Clermont. 21. 449. 16 Watts' Dictionary. 248. 8 Drechsel. A. C. P. 127. 150. 17 Riclter. 24 Bromeis. A. C. P. 35. 106. 9 Gay Lussac & Pelouze. P. 18 Husemlann. 26. 25 Bromeis. A. C. P. 35. 104. A. 29. 111. 158 SPECIFIC GRAVITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. Pimelic acid. C7 H112 04. I 14. 2Suberic C8 H14 04. I20.0 (1(( 140.0 rs. 138'5. 4 Anchoic, Azelaic, or C9 H16 04. I I4~-I i6.3 5 Lepargylic acid.,( II 5 —1 24.0 6 " IO6.~ rs. I04.~ Sebacic (( C10 H1s 04..1317, melted. I27.0 8Roccellic " C17 H32 04. I32.~ S. I08. 12th. CARBONATES, LACTATES, AND LEUCATES, OF THE ETHYL SERIES. Name. Formula. Specific Gravity. B ng Melting Point. Point. 9 Ethyl carbonate. C4 E-o. C 03. I25.0 10 I 26.0 (( 975 90 I25-I6.~ i2,975, I9~0 I3_j" —I29,, 12,,.9998, o.' 12305 to 1'3 C (C (C.9780, 20.~ I12598.'4 Butyl s C8 H18 C 03. I90. I"Amyl C(I H,,2 C H C.9144. 224.~ 6 ( (.9065, 1595. 226.0 17 Ethyl ortho carbonate. C, H20 04.- 925 j I58-I59. c 18 lactate. C5 H10 03. I.0542, 0.0t 56.~ 19 1.042, I3.-0 753 m. m. 20 Diethyl] ( C7 H14 0,.9203, o.~ I 56?5 [For dilactates and trilactates, see " miscellaneous ethers."] 21 Methyl leucate. C7 H14 03..9896, T6?5. I65.0 22'Ethyl, Cs H16 0.3.9613, 187-7. I75.0 23Ainyl ( C,, H22 03..93227, 13-0 225.~ AUTHORITIES.'Laurent. A. C. Phys. (2). 9 (ahours. 18 W urtz & Friedel. 14. 373. 66. 163. 10 Clermont. 7. 561. 19 Wurtz & Friedel. 14. 373. 2 Bromeis. A. C. P. 35. 97. 11 Ettling. A. C. P. 19.17. 20 WUrtz. 12. 294. 3 Dale. C. S. J. 17. 258. 12 Kopp. 18. 21 Frankland & Duppa. 18. 4Buckton. 10. 303. 13 Kopp. 18. 378. 5 Wirz. 10. 298. 14 Wurtz. 7. 574. 22 Frankland. 16. 376. 6 Dale. C. S. J. 17. 261. "15 Aedlock. 2. 430. 23 Frankland & Duppa. 18. 7 (arlet. 6. 429. 16 l Bruce. 5. 605. 380. 8 Hesse. A. C. P. 117. 336. 17 Bassett. 17.477. SPECIFIC GRA VITY TABLES. 159 13th. OXALATES, SUCCINATES, &c., OF THE ETHYL SERIES. Boiling Melting Name. Formula. Specific Gravity. Point. Point. 1 ethyl oxalate. C4 16 04.6 I6. 51.o 2 (( 1 635. (( (( (( I. I566, 50.~ 4 Methyl-ethyl oxalate. C5 HS 04 I.27, 12.0 I6o0-I70.0 5 Ethyl C6 H0 04 I1.0929, 7.5. I83~-I84.~ 6 o cc(( I.o86, 12.~ 186.0 c7 i(( (( I.ioi6,.~ S6.0 8 ( (( I.o8i 5, 18.~2. f 9 c ct ct I.C'%124, 15.~ 10 Ainyl c, C12 H22 04. 262.0 11 ( ( (C 260. 12 (C ((.968, 11.0 26.0 -:' Mlethyl succinate. C, Ho 04. 1.11 I79, 20.0 9S8.0 20.s. I6 ]4Ethyl (( 1 C 4 H1, 04. 1.036. 214.0 5 (( cc (( 2 i4.~ 17 (( (( I.0475, 25? 21753 1 Isopropyl (( C10 1 04. 1.009, 0.0 228.0 19.997, 85 76I m. m. 20 Cetyl C2 C36 H70 04 58.0 21 Ethyl pyrotalrtrate. C 11,6 04. 2 18.0 22 d( adipate. CIO 118 04 I.001, 20 5. 230.0 23 ( pinselate. C 0 4 IS5.~ 2 Ethyl (( C1, 112 04. 1.003, I 8. 26 anchoate. C13 H2 04. 325.0 27 MAlethyl sebate. C(12 H22 04, 285.0 2505. 28 Ethyl C14 H26 04. 308s. AUTHORITIES. I Dumrnas & Peligot. A. C. 10 Balard. A. C. Phys. (3). 20Tiittscheff. 13. 406. Phys. (2). 58. 44. 12. 311. 21 Watts' Dictionary. Delffs. 7. 26. 11 Cahours. 22 Malaguti. A.C.P.5G. 306. 2 Kopp. 18. 12 Delffs. 7. 26, 23 Marsh. 10. 303. 4 Chancel. 3. 470. 13 Fehlig. A. C. P. 49.195. 24 Laurent. A. C. Phys. (2). ~ Dumas & Boullay. P. A.'4 DArcet. A. C. Phys. (2). 66. 162. 12. 430. 58. 291. 25 Laurent. A. C. Phys. (2) 6 Delffs. 7. 26.'1 Fehling. 66. 160. 7 Kopp. 18. 16i Kopp. 18. 26 Buckton. 10.304. 8 Kopp. 18. 17 Kopp. 1. 27 Carlet. C. R. 37. 128. iMendelejeff. 13. 7. 1 Silva. C. 1. 69. 416. 28 Carlet. C. R.37.128. 19 u Silva. C. R. 69. 416. 160 SPECIFIC GRAVITY T4ABLES. 14th. COMPOUNDS OF ALLYL AND DIALLYL. Boiling Melting Name. Formula. Specific Gravity. Point. Point'Allyl alcohol. C3 1IG O. I03.0 2 0 920-94.0 3 930-96.0 (( (o (( 04 A.8581, 0.0 ~ 00-92.0 S.-50.0 ~8478, 27.0 6o.8709, 0.0 (7 o ( ( ((.81832, 62.0 960-97.0 8(( ( ((.7846, 97. 9 (C 920~-950 10 Diallyl monohydrate. C6 H,,2 0..8367, o.0 930-95. 1 ( dihydrate. C6 H1402..9638, - 212-2015.0 12.9202, 65.0 13 Pseudo diallyl alcohol. C(1 H12 0..86o4,4 14 (( (.8625,.4 t5 Allyl oxide. C6 111 0. 850-87.0 16 ( 82.0 17 Ethyl allyl oxide. C5 H10 0. a. 64.0 18 (( 625.'9Amyl allyl, C8 H16 O. a. I20.0 20 Allyl formate. C4 1H6 02..9322, I7~5. 820-83.~' 21, acetate. C5 H8 02. 970~-100oo.~0 22 (( (1 (( 22 05.0 23 butyrate. C7 H,2 02. a. I45.0 24 (, a. 140.~ 23 ( valerate. C8 H14 02. I62.0 26 Diallyl monacetate. C8 H]4 02..912. I50~-I60.~ 27 diacetate. C1O H18 04. I.oo9, 0.~ 2250-230.0 28Ethyl allyl acetate..9222, 0.0 1330-I35.0 29 Allyl oxalate. C8- HO 04. 1.o55, 155. 206-207.0 AUTHORITIES. Hofmann & Cahours. 9. 10 Wurtz. 17. 515. 20 Tollens,'Weber & Kempf. 583. 1 f Wurtz 17. 513. 21. 450. [585. 2 Erlenmeyer. 17. 489. 12 Wurtz. 17. 513. 21 Hofinann & Cahours. 9. 3Tollens, Weber & Kempf. 13 Wurtz. 17. 515. 22Zinin. 8. 618. [589. A. C. P. 156.132. 14 Wurtz. 17. 515. 23 Berthelot & De Luca. 9. 4 r Tollens and Henninger. 15 Berthelot & De Luca. 9. 24Hofmann & Cahours. 9. | A. C. PR 156. 134. 590. [583. 586. 5 Tollens and Henninger. 16 Hofmann & Cahours. 9. 25 Hofmann L& Cahours. 9. A. C. P. 156.134. 17 Hofmann & Cahours. 9. 586. 6 (Tollens. A. C. P. 158.104. 583. 26 Wurtz. 17. 514. 7 Other Specific Gravities 18 Berthelot & De Luca. 9. 27 Wurtz. 17. 513. 8 are also given. 590. 28 Wurtz. 21. 446. 9 Hiibner & Mluller. A. C. 19 Berthelot & De Luca. 9. 29 Hofmann & Cahours. 9. P. 159. 174. 590. 585. SPECIFIC GRAVITY I'ABLES. 161 Name. | Formula. Specific Gravity. Bointg Poing Point. Point.'Allyl benzoate. C1o H0 02. 242.0 2 (( (( (( 230.~ (( (( (o 228.0 15th. GLYCERINE, GLYCERIDES, AND ALLIED COMPOUNDS. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 4Glycerine. C3 H8 03. 1.27, I0.0 (( 1.28, 15.0 6 I.260, I 55. 7 7( 1.115, 12?5. 8 I.2636, I5.0 9 oI(1.26949, 6?7. ) o 1.26244, I6.6. VTriethyl pyroglycerine C12 H26 0. I.oo00, I4.~ 2880-290.0 12Tetrethyl triglycerine. C17 H36 07. 1.022, I4.0 3Ethyl glycide. C5 H0o 02. aI.oo. I28~-I29.0 14 Ainyl (( C8 H16 02..90, 20.0 I 88. 5 Aceto-glyceral. C5 H10 03. I.o8i, o.~ I84~-I88.~ 16 Valero-glyceral. C8 H16 03- 1.027, 0.0 2240-228.0 7' Trimethyline. C6 H14 03..9483, o.0 148.~ 18 Monethyline. C5 H-12 03. 2250-230.~0'9 Diethyline. C7 H16 03-..92. a. 9 I. 20Triethyline. C9 1120 03-.8955, 15.0 I86.0 21 Ethyl ainyline. C0O H22 03..92. 2380-240.0 22 Monanyline. C8 118 03..98, 20.0 2600-262.0 23 Diamyline. C13 H28 03..907, 9.0 2720-274.0 24 Mono allyline. C6 H12 03 I. I 6o, 0. 240. 25o 1.1013, 25.0 a. 24. 26 Monacetin. C5 H1 ~04. 1.20. 27 Diacetin. Acetidin. C7 H12 05- I.I84. 280.0 AUTHORITIES. 1 Zinin. 8.619. 9 ( Mendelejeff. A. C. P. 7 Alsberg. 17. 495. 2Berthelot & De Luca. 9, 114. 165. [114.165. 18 Reboul. 13.466. 589. 10 Mendelejeff. A. C. P. 9 Berthelot. 7. 450. 3 Hofmann & Cahours. 9. 11 Reboul & Louren9o. 14. 20 Alsberg. 17.495. 586. 675. [675. 21 Reboul. 13. 465. 4 Chevreul. 12 Reboul & Lourenco. 14. 22 Reboul. 13. 464. 5 Pelouze. A. C. Phys. (2). 13 Reboul. 13. 465. 23 Reboul. 13. 465. 63. 19. 4 Reboul. 13. 463. 24 Tollens. A. C. P. 156. A49. 6 Watts' Dictionary. 15 f Harnitsky & Menschut- 25 Tollens. A. C. P. 156.149. 7Socoloff. A. C. P. 106.95. kine. 18. 506. 26Berthelot. 6. 455. 8 Mendelejeff. 13. 7. 16 Harnitsky & Menschut- 27 Berthelot. 6. 455. [ kine. 18. 506. 162 SPECIFIC GRA VITY TABLES. Name. Formula. Specific Grav oint Point. ty- Point. Point.'Triacetin. C9 H4 06. I. 174. 2 Monobutyrin. C7 H14 04. I.o88. 3 Dibutyrin. Butyridin. C11 H O20 1 5 0 I. 8 i. 4 (( (( (( I1.084. J 5Tributyrin. C15 H26 06. I.o56. 6 IMonovalerin. C8 H16 04. I.Ioo. 7Divalerin. C13 H24 05. 1.059. 8 Laurostearin. C7 H112 0~. 440-450 9Cocinin. C42 1180 06..92, 8.~0 s. 10 Myristin. 86 6 3I 11 nIonopalmitin. C19 Hs38 04 58.~ s. 45~0 12 Dipalim, itnin. C35 H68 O. 59.0 S. 5I.~ 13 Tripalmitin. C51 198 06 6o. S. 46.0 14 (( 1st. modification (( 46.0 15 (( 2(d. (( 61c7' i- s. 45?5. 16 (( 3d. " (( 62C8. J 17 Monostearin. C21 H4 04. 61.~ s. 60.0 18iDistearin. [tion. C39 H76 05. 58.0 s. 55.0 19 Tristearin. 1st. nmodilica- C57 H11 06.987, 10-. 60.0 20 (( (( (( ((.9872, I 5.~ 65.~ 21 (( {"(' ((.9877, I 5. 65?5. 22 (( (( ((.9867, I5.9600, 5 1? 5) 24 (( 2d. 0( (0 I.0I0I, I5.0 69?7. 25 (( 3d. 1 (( 01.78, I5.0 26 (( (( (( (( I 79, I5. 69?7. 27 (( ( (( I.009, 5 I5- S. 50.5-5 17. 28 (( {( (1 (( 6 993I, 65 - 29 (( (( (( (( 974, J 30 O LiqUi(d. ((.9245, 65?5. 31 Diarachin. C43 1184 05. 75.0 32 MIonolein. CC21 H140 4..947. 3Diolein. C69 1173 05..92, 2I.~ S. 15.~ AUTHORITIES. 1 Berthelot. 7. 449. 12 Berthelot. 6. 453. 23 Duffy. 5. 510. 2Berthelot. 6. 455. 13 Berthelot. 6. 453. 24 Duffy. 5. 510. 3 Berthelot. 6.455. 14 (Duffy. 5.511. 25 Duffy. 5.510 and 5.511. 4 Berthelot. 6. 455. 15 uffy. 5.511. 26 Duffy. 5. 510 and 5. 511. 5 Berthelot. 7. 449. 16 ( Duffy. 5. 511. 27 ~ Duffy. 5. 510 and 5. 511. 6 Berthelot. 6. 454.'17 Berthelot. 6. 452. 28 ] Duffy. 5. 510 and 5. 511. Berthelot. 6.454. 18 Berthelot. 6.453. 29 L Duffy. 5.510 and 5. 511. 8 Marsson. A. C. P. 41. 329. 9 Kopp. A. C. P. 93. 194. 30Duffy. 5.510. 9 Brandes. Watts' Dict. 20Duffy. 5. 510. 31 Berthelot. 9.494. 70 Playfair. P. M. (2). 18.102. 21 Duffy. 5. 510. 32 Berthelot. 6. 454. 11 Berthelot. 6. 453. 22 P Duffy. 5. 510. 33Berthelot. 6. 454. SPECIFIC GRAVITY TABLES. 163 16th. SACCHARINE, STARCHY, AND GUMMY BODIES. G i Boiling Melting Name. Formula. Specific Gravity Point. Point. 1Cane sugar. C12 H22 011. i.600. 2 I.606. 160.0 3 o C I1.593. C CCC 1.596. 6 CC C o 1.5578. 6 Milk ( I-534. 7 C'( 1.-53398, 4.0 8MIelezitose. ( Below I40.~ 9 Mycose. C12 H2 O011.2aq. 00.0 ~(Glucose. Anhydrous. C6 H12 06. 146.0 Cryst. C6 H12 06 H20. 1.386I. 12 CC (C I.39. I 13 CC (( (( 1.54-I.57, I I. 14 Sorbite. C6 H112 06. 1.654, I5.0 15 Inosite. C6 H12 06. 2aq. 2I0~+. 16 (( Crystals. (( I.II54, 5~. 17 Pinite. C6 H12 05- 1.520. 18 Quercite. ( 235.0 19 Mannite. C6 1114 06 a. 200.0 Ii60~-I65.0 20 Dulcite. (( a. I 90.~ 21 (( (8( I8.~ S. I8 I. 22 (( u I82.~ 22 (182.~ 23 (( (( I.466, I 5.~ I86. 24 (( I87.0 25 Erythromannite. C4 H10 04 I.590. I I2.0 26 (( (( 20. 27 Starch. C6 H110 05 1.505. 28 I. 5 30. 29 (( I.56. AUTHORITIES. I Schuibler & Renz. See It. 1 Payen & Persoz. 21 Jacquelain. 3. 536. 2 Srisson. 12 i Payen & Persoz. 22 Gilmer. A. C. P. 123. 372. Filhol. See 26. 13 B6deker. 26. 23 Eichler. 9. 665. 4 Playfair and Joule. 11. 4 Pelouze. 5. 655. 24 Bouchardat. Z. F. C. 14. 5 Brix. 7. 618. 1' Scherer. 3. 538. 349. 6Filhol. See 26. 1i Vohll. 11. 489. 25 Lamy. 5. 676. 7 Playfair and Joule. 14. 17 Berthlelot. 8. 675. 26 Hesse. A. C. P. 117. 328. 8 Berthelot. A. C. Phys. (3). 18 Dessaignes. A. C. P. 81. 27 Payen. W~atts' Dictionary. 55. 282. 103. 28 Dietrich. Zeit. An. Chenl. 9 AMitscherlich. A. C. P. 106. 19 Watts' Dictionary. 5. 51. 15. 20 Laurent. 3. 535. 29 Kopp. A. C. P. 35. 38. 10 Schmidt. 14. 720. 164 SPECIFIC GRAVITY TABL.S. Name. Formula. Specific Gravity. Boiling Polint Point. Point.'Starch. Arrowroot. C6 I10 05. 1.5045, air dried. 2 Potato. (( 1.5029, (( (( (( (3( ( I.6330, dried at Ioo.~ J 4 Cellulose. (( 1.525Gum. C12 H22 1 I. 1.487, air dried. (C,,,, 1.525, dried at Ioo.~ (( Gum arabic. I.355. 8 (( (,, tragacanth.. 3545. ( Senegal. (( I436. 10 Bassora gunm. I.359 J 17th. MISCELLANEOUS ACIDS. Boiling Melting Name. Formula. Specific Gravity. Boiling Metin I Crotonic acid. C4 H6 02. 72.~ s. 7005. 12 Angelic (( C5 H8 02. I 90. 45.' -. Pyroterebic acid. C6 H1o 02- I.OI. 2000+. 4 (( ( ((2IO. i5Ioringic, C15 H28 02-.908, I2~5. 16 Hyposcic o C16 H30 02. 340-3 5.0 17 Oleic (( C18 H34 02..8o8, 19.0 18 (( I4.' S. 4.0 19 Brassic e 31 0 192BraSSic, C22 42 02. 320-33.0 30 ((,((Erucic. (( 34.0 s. 33.0 21 Isopropacetic acid. C5 H11 02..95357, 0.0 I75.0 32:\ethyl diacetic o C5 HS 03..037, 9.0 I69~-I70.0 23Ethyl C6 H1o 03. I.03, 5.0 I8o08. 24 ethyl glycollic ( C3 H6 03. i. 8o. I98.0 25Amyl C7 H14 03. I.003. 235.~ AUTHORITIES. 1 (Fluckiger. Z. F. C. 10.445. 9 Guerin-Varry. P. A. 29. 16 G6ssmnann & Scheren. 8. 2 Fliuckiger. Z. F. C. 10. 445. 50. 521. 3 Fl ickiger. Z. F. C. 10.445. 10 Giierin-Varry. P. A. 29. 17 Chevreul. 4 Weltzien's "Zusammen- L 50. 18 Gottlieb. A. C. P. 57. 43. stellung." n1 Kekul6's " Lehrbuch." 19 Websky. J. F. P. 58. 453. (f Fliickiger. Z. F.C. 10.445. 12 Meyer & Zenner. A. C. P. 20 Darby. 2 347. 6 j Flfickiger. Z.F. C. 10.445. 55. 321. 21 Frankland & Duppa. 20. 7 Guierin-Varry. P. A. 29. 13 Rabourdin. A. C. P. 52. 396. 50. 395. 22 Brandes. 19. 306. 8 Guerin-Varry. P. A. 29. 14 Chautard. 8. 652. 23 Geuther. 18. 303. p50. 15 Walter. C. R. 22. 1143. 24 Heintz. 12. 359. 25 Siemens. 14. 451. SPECIFIC GRAVITY TABLES. 165 Boiling Melting Name. Formula. Specific Gravity. Boiling Metint. 1 Quartenylic acid. C4 H6 02- I.OI8,25.0~ 17 I9~ 2Honlolactic ~ C2 H4 03..I197, I3.0 3 Linoleic " C16 1128 02-.9206, I4.0 4 Ricinoleic, C18 1134 03-.940, I 5.0 s.-6~to-IO.~ 5 Sorbic " C6 H8 02. 13495. 6 Parasorbic i.o68, I 5. 221.0 7 Hydrosorbic C6 H0 023.969, I9.0 204~5. 9Pyroracernic ( C3 H4 03-. 1.288, I8.0 1. I65-~ 9 Citric C CG H8 07. 1.617. O (( (( (( 10 I1.542. 11 1.553. 12 Tartaric C4 H6 06. 1.75. 13 I11.764. 1 (( (( (( 4 (( (( (( 1739.'3 Racemic acid. Dextro. C4H606. H2 0 I1.75. 16, (( Laevo. " 1.7496. 17 (.69. 18 Methyl salicylic acid. C8 H8 03- I.8, IO.~ 222.0 19 Ethyl (( ( C9 H10 03. 225.~0 20 I( (C 1.097. 229~5. 21 ( ( c I. I843, IO.~ 221.0 22 AmvI c c C12 H16 03. 270.0~ 23 Cinnlniic (( C9 H8 02. 1.245. 30O'-304.0 I 29.0 24 1.195. 24 (( (( (( I *9 5' 25 Benzoic o C H6 02-. I.29. Cryst. 26 o(( ( 1.201, 21.0 Solid. 27 (C (( 1.206, 2598.} 28 C(C 1.227, 27.0 Liquid. 29 o( 1( (( I.o838, I214 249i. 121 4. 30 Alpha toluic o C8 H8 02. I.3. Solid. 31 I1.0778, 83.0 65 6 32 1C C I.O334, 135.0 26505. 7695. AUTHORITIES. 1Geuther. J. F. P. (2). 3. 2 Richter. 21 Delffs. 7. 26. 442. 13 Schiff. 12. 41. 22 Drion. A. C. P. 92. 314. 2 Clo6z. 5. 497. 14 Buignet. 14. 15. 23 E. Kopp. J. F. P. 37. 280. 3 Schiler. 10. 359. 15 Pasteur. 2.309. 24 Schabus. 3. 392. 4 Saalmiiller. 1. 562. 16 Pasteur. A. C. Phys. (3). 25 Kopp. 5 Hofmann. C. S. J. 12. 43. 28. 72. 26 Mendelejeff. 11. 274. 6 Hofmann. C. S. J. 12. 322. 17 Buignet. 14. 15. 27 j Mendelejeff. 11. 274. 7 Barringer & Fittig. Z. F. C. 18 Cahours. A C. Phys. (3). 28 (Mendelejeff. 11. 274. 13. 425. 10. 327. 29 Kopp. 8. 35. 8Vo61ckel. 6. 426. i9Cahours. A. C. Phys. (3). 30 Modller&Strecker. 12.299. 9 Richter. 10. 360. 31 M6ller&Strecker. 12.299. 1o Schiff. 12.41. 20 Baly. C. S. J. 2. 28. 32 M6ller&Strecker. 12.299. n Buignet. 14. 15. 166 SPECIFIC GRAVITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Point. Point.'Pimaric acid. C20 H30 02. 1.047, I8.~ 155.~ 2 Sylvic (( I.IOI I, I8.~ I62.0 3 Ellgenic. C0 H1112 02. I.076. 242.0 4 (( (1 (( 1.0684, I4.0 251.' 5 Quinic oC7 H,1 06. 1.637, 825. 6 6(1 (( 16 I6. 7 (( ( (( I6 I -I 62? Ethyl camphoric acid. C12 H20 04 I.o095, 2005. I96.~ 9Diethyl camphresic acid C, 1122 07. 1.i28, I3.0' Phycic acid..896. Solid. I50o.~ d. I 36.0 For salicylous acid, see "Salicylol." For carbolic acid, see " Phenol." 18th. MISCELLANEOUS ETHERS OF THE ETHYL SERIES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. " Ethacetic ether. C6 H12 02..8942, o.0 I I9.0 12 Diethacetic (( C8 H11 02.8822, o0.0 151. 3 Ethyl isopropacetate. C7 14 03..8882,0.0 I340-135-0 14 (( (( ((.87 I66, I8.~) 758.4 m. m. 1o Methyl methyldiacetate C6 H1 0. I.020, 9.0 I77O4. 6 Ethyl (( 7 1112 03..995, I4.~ I89?7.'7 Methyl ethyldiacetate. ( I.009, 6.0 I86?8. 18 Ethyl C(8 H14 03..998, I 2.~ I98.~'9 ( ethylglycollate. C6 H12 03..978. 20 (( dimethoxalate. ((.9931, 13.0 21 ( ethomethoxalate. C7 H14 03..9768, I3.~ I6505. 22 Methyl diethoxalate.,.9896, 1615. 165.~ 2 Ethyl (( C8 H1i 03..96I3, 1827. I75-~ 24 ( amylhydroxalate. C9 118 03..9449, I3.- 203.0 2 ethylainylhydroxalate. Cll H22 03..9399, I3.~ 2240-225.0 AUTHORITIES. I Siewert. 12. 510. 10 Lainy. 5. 675. l9Scelreil)er. Z. F. C. 13.168. 2 Siewert. 12. 510.'1 Frankland & Duppa. 18. 20 Franklaiid & Duppa. P. T. 3 Stenhouse. 8. 655. 306. [308. 1866. 309. [381. 4 Williams. 11. 272. 12 Frankland & Duppa. 18. 21 Frankland & Duppa. 18. 5 Watts' Dictionary. 13 { Frankland & Duppa. 20. 22 Frankland & Duppa. P. T. 6 Hesse. A. C. P. 114. 292. [ 396. [396. 1866. 309. [1866. 309. 7 Zwenger & Siebert. A. C. 14 Franklalld & Duppa. 20. 23 Frankland & Duppa. P. T. P. 1st. supp. 79. 15 Brandes. 19.306. 24 Frankland & Duppa. 18. 8 Malaguti. A. C. Phys. (2). 16 Brandes. 19. 306. 382. [1866. 309. 64. 164. 17 Geuther. 18. 303. 25 Frankland & Duppa. P. T. 9 Schwanert. 16. 397. 18 Geuther. 18. 303. SPECIFIC GRAVITY 7lABLES. 167 Name. Formula. Specific Gravity. Boiling Melting Name. Point. Point. Amyl diethoxalate. C11 H. 03..93227, I 3.0 225.0 2Ethyl diamyloxalate. C14 128 03. g9137, I3-0 262.0 ( ethylcrotonate. CS H14 02..9203, 3.0 I65.0 4 tiglate. C7 H12 02..926, 21.~ I56.0 5 quartenylate. C6 Ho0 02..927, i9.0 136.0 6Acetoglycollic ether. C6 H 04. I.0093, I7-0 I79-~ 7 Acetyl lactic C7 H12 04. I.0458, I7~0 177.0 8Lactobutyric (( C9 H16 04. 1.024, 0.~ 200~-2IO0.0 9 ( (( (( I.028, O.~ 208.0 10 Lactosuccinic ether. C11 His 06..I 19, O.~ 280.~ 11 Ethyl dilactate. C8 14 05 I. I34, 0.~0 235.0 12 Diethyl trilactate. C123 H22 07. a. 270.0 13 Diethyl glycollic ether. C20 H36 010. I.OI, 19.0 25I~-255.0'4Diethyl glyoxylic ( Cs H16 04..994, I8.~ I9972.'5 Benzoyl glycollic C1 HK 4. I.509, 2024. 28624-28824'6Methyl oleate. C19 H36 02..879, 18.0 17 Ethyl C20 H38 02..87I, 18.0 M etyl elaidate. C19 H36 02..872, 18.0'" Ethyl ( C20 H38 02..869, I 8.~ 370.0 20 citrate. C1, H20 07. I.142, 2I.0 283.0 21 citraconate. C9 H14 4. 1.040, I8~5. 225.0 22(( mesaconate. ( 1.043, 20.0 220.0 (( aconitate. C12 H s O6. 1.074, I4.0 236.~ 24 fumarate. CS H12 04. 1.106, I I.0 225.0 2 (( veratrate. C11 1114 04 1.141, 18.0 S. 42. 2 ( pyromucate. C8 H 0.2- 1.297, 20. ~ 2080~-2I.~ 34.0 27 Methyl mucate. C 8 1G 08. 1.48-1.50, 20.0 28 Ethyl C(( 10 H18 O. 1.I17,-1.32, 20.~ I50os 135? 29 camphorate. C14 H24 04. I.029, I6.0 285~-287.~ 30 paracamphorate. 1( I.03, I5.0 270~-275.~ 31 camphresate. C16 H2 07. I.o0775, I3.0 32 Methnyl cinnamate. C0 H10 02- I. I o6. 24I.~ 33 Ethyl ( CH H112 02. 1.126, o.0 262.0 AUTHORITIES. IFrankland & Duppa. P. T. 11 Wurtz & Friedel. 14. 377. 22 Pebal. 4. 404. 1866. 309. [383. 12 Wurtz & Friedel. 14. 377. 23Watts' Dictionary. 2 Frankland & Duppa. 18. 13 Geuther. 20. 455. 24 L. Henry. A. C. P. 156. 178. 3Frankland & Duppa. 18. 14 Schreiber. Z. F. C. 13.168. 25Will. A. C. P. 37. 198. 384. 15 Andrieff. 18. 344. 26 Malaguti. J. F. P. 41. 224. 4Geuther & Frohlich. Z. F. 16 Laurent. A. C. Phys. (2). 27 Malaguti. A. C. Phys. (2). C. 13. 549. 65. 294. [65. 294. 63. 86. [63. 86. 5 Geuther. J. F. P. (2). 3. 444. 17 Laurent. A. C. Phys. (2). 28Malaguti. A. C. Phys. (2). 6 Heintz. 15. 292. 18 Laurent. A. C. Phys. (2). 29 Malaguti. A. C. P. 22. 48. 7Wislicenus. 15. 300. 65. 294. [65. 294. 0 Chautard. 16. 395. sWurtz. 12. 295. 19 Laurent. A. C. Phys. (2). 31 Schwanert. 16. 397. 9Wurtz. 13. 273. 20 Malaguti. A. C. P. 21. 267. 33 E. Kopp. C. R. 21. 1376. 10 Wurtz & Friedel. 14. 378. 21 Watts' Dictionary. 33 E. Kopp. C. R. 21. 1376. 168 SPECIFIC G.RAVITY TABLES. Boiling Melting Name. Formula. Specific Gravity. Point. Point. Ethyl cinnamate. C,1 H12 02 205.~ 2 I.I3. 260.0 s3,( o( 262.0 4 1.o656, o0. 266.0 5 I(( (.0498, 20?2. 760 m. m. 6 Methyl benzoate. C8 H8 02. I.IO, I7.0 I98~5. 7 (( (( (( 1.1026, 0.0~ s8 (( (( ( I.o876, 163. 9 I.092, 123.'10Ethyl (( C9 H10 02. I.o539, IO5$. 209.0 11 I.o6, I 8. 2080-209.0 13 I 1.049, I 4.0 207.0 13 ( i I.o657, 0. t 2 14 1.0556, io. 229. 15 (5.057, 14.1. 6 Amyl 5, C12 H16 02. 100oo39, o.~ 2607. 1?7 ( (C ('.9925, I474.18 ( 2520-254.0 9 Isopropyl ( C10 H12 02. 1.054, 0. 218.0 20 (.3, 25.0 762 m. m. 21 Ethyl toluate. (( 228.0 22 xylylate. C,, H14 02. 233.0 23 (( cuminate. C12 H16 02. 240.~ 24M Methyl homotolhate. C10 1112 0. II0455, 4~0) 25 i.oi8, 49,0f 238~-239'0 26 Ethyl 1 C11 H14 02..o0343, 0 247. ~ 27 (((5.9925, 49'~0 247-249. 28 Amyl C14 H20 0.2 9807, 0o.0 29I-2930 29 (C (5.9520, 49.0 10 Diethyl oxybenzoate. C1 H14 03. I.o875, o.0 26 0 31 ((( ((.0725, 20.0 263 32 Methyl phenylacetate. C9 H9 02. (?) I.o44, I6.0 220.0 33 Ethyl C1O H12 02.(?) I.03I. 226.0 AUTHORITIES. 1 Plantamour. A. C. P. 30. n Deville. A. C. Phys. (3). 23 Gerhardt & Caliours. 344. 3. 188. 24 { Erlenmeyer. 19.366 and 2Marchand. A. C. P. 32. 269. 2 Delffs. 7. 26. 367. [367. 3 Herzog. Watts' Dictionary. 13 f Kopp. 18. 25 Erlenmeyer. 19. 366 and 4 Kopp. 18. 14 Kopp. 18. 26, Erlenmeyer. 19. 367. 5 Kopp. 18. 15 Mendelejeff. 13.7. 27 Erlenmeyer. 19. 367. 6Dumas & Peligot. A. C. 16f Kopp. 18. 28f Erlenmeyer. 19. 367. Phys. (2). 58. 50. 17 1 Kopp. 18. 29 Erlenmeyer. 19. 367. 7f Kopp. 18. 18 Rieckher. 1. 699. 30 Heintz. A. C. P. 153.332. 8 1 Kopp. 18. 19 f Silva. Z. F. C. 12. 637. 31 Heintz. A. C. P. 153. 332. 9 Mendelejeff. 13.7. 20 Silva. Z. F. C. 12. 637. 32 Radsizeski. Z. F. C. 12. 1o Dumas c& Boullay. P. A. 21 oad. 1. 715. [C. 7. 345. 358. [358. 12. 430.'2 Hirzel & Beilstein. B. S. 3' Radsizewski. Z. F. C. 12. SPECIFIC GRAVITY TABLES. 169 19th. MISCELLANEOUS. Name. Formula. Specific Gravity. Boiling Melting Point. Point.'Dimethylene carbonethylene ether. C8 H14 03..998, 12.~ I98.0 2Aldehyde diacetate. I.07, IO.~ 3Acrolein acetate. C7 H1O 04 1.076, 22.0 180.0 4M3ethylal. C3 H8 02..855I. 42.0 5Diinethyl acetal. i C4 H,0 02-.8555, 0.0 65.0 6 ".8674, 1.0 6404. 7.8787, o.0 8 I((!.8590, 14.0 (9 (' (C.8503, 22.0 63~-64.~ cc10 ((.8497, 23..0 11 (.8476, 25.0'2iMethyl, C5 H12 02-.8535, o.0 85.0 3Acetal. j C6 H14 03..842, 21.0 75. 0 14 C(.823, 20.0 9592. 15 o.821, 2294. I040-I06.0 16 ((04. 17 Dimethyl valeral. C7 H16 02..852, IO.~ I24.0'8 Diethyl (( C C1 H2 0..835, 12.0 I5802. l9Diamyl acetal. C12 H,,26 02-..8347, I5.0 2Io08. 20 (( valeral. C,15 H32 02..849, 7.0 240~-255.0 21 Valeral diacetate. C H16 04-.963. I95.~ 22 Derivative of valeral. C,0 H18 O..9027, 17.0 2500-290.0 2= Ethyl diacetone carbonate. C10 1118 03..9738, 20.0 2I0~-2I 2.0 24 ethacetone ( C8 H14 03..9834, I6.0 195.~ 25 " dilmethacetone((.99I3, I6.0 184.0 26 " isopropacetone(( C9 H16 03..98046, o.~ 201.0 27 Acetyl valeryl. C7 H12 02..8804, I5~5. 28 Metacrolein. C6 H8 02- I.03, 8.0 29 Mesityl oxide. C6 H10 0..848, 23.0 I31.~ AUTHORITIES. 1 Geuther. 16. 324. 12Wurtz. 9. 597. 23Frankland & Duppa. 18. 2 Geuther. 17. 329. 13 D6bereiner. 306. 3 Hiibner & Geuther. 13.307. 14 Liebig. A. C. P. 5.25. 24 Frankland & Duppa. 18. 4 Malaguti. A. C. Phys. (2). 15 Stas. 1. 697. 307. 70. 394. 16 Wurtz & Frapolli. A. C. P. 25 Frankland & Duppa. 18. 5 Wurtz. 9. 597. 108. 223. 309. 6 Alsberg. 17. 485. 17 Alsberg. 17.486. 26 Frankland & Duppa.''0. 7 (Dancer. 17.484. 18 Alsberg. 17. 486. 395. 8 Dancer. 17. 484. 19 Alsberg. 17. 485. 27 Olewinsky. 14. 463. 9'Dancer. 17.484. 20 Alsberg. 17. 486. 28Geuther. 17. 334. 10 Dancer. 17.484. 21 Guthrie & Kolbe. 12. 365. 29 Fittig. 12. 344. 11 (Dancer. 17. 484. I 22 Borodin. 17. 339. 12 170 SPECIFIC GRAVITY T.ABLES. Boiling Melting Name. Formula. Specific Gravity. Boilig Meting Point. Point. 1 Acrolein. C3 H4 0. 5204. 2Pinacone. 1 C6 H14 02..96, 15.0 I760-I77.0 3Isobenzpinacone. 1. C26 H22.2- I.I0, I9.0 297~5.4 Acropinacone. C6 Ho 002..99, I7-0 I60~-I80.0 5Pinacolin. C6 H120. (?).7999, I6.0 105.0 6 Phorone. C9 H140. (?j.939, I2.~ 7 o (C.932, 12.0 8 o( Camphorone. o.96I4, 20.~ 9 I 96.0 20.0 10~Diacetyl conylene. C12 H20 04-.988, 18.2. 225.0 n Derivative of chloroform C7 H,6 03-.8964, I45~-I46.~ 12 Triethyl propylphycite. C9 120 04-. 976, 013 1 o (( ((.9605I, i65.14 Diethoxyl ether. C8 H18 03-..8924, 21.~ 168.0 15 Citraconic anhydride. C5 H4 03 I.247. 16Camphoric (" s. C,0 H14 03. I.I94, 20?5. 270.0 217.0 17 Camphor. C0O H16 0..986,-.996. s Patchouli camphor. C30 118 - 0 I.05I, 495. 296.0 540-550 19 Ethylated camphor. C12 H20 (..946, 22.0 226~-231.~ 20 Amlylated (( C1, H26 0-..99, 15.0 2720-275.0 21 Acetyl (( C12 H, 02..986, 20.0 2270-230.0 22 Ethylated borneol. C2 -122,, 0..9 16, 23.0 20205. 23~ MAethylated (( C11,, o. *933 I 5. I19495. 24Camlphrene. Cs H2, 0..974, 6-~ a. 240.~'5 Acetyl camphrene. C20 1130 02-. 954, I 8. 230~-240.~ 21 Styryl alcohol. C9 H1o 0. 254.0 8.~ 27 Anisaldehyde. C8 H18 0. 1.09, 20.~ 2530-25 5.0 28 I 1.1228, 18.0 2470-248.0 29 Salicylol, salicylous acid, C7 H62 I. 731, 1393. I9695. 30 or salicyl hydride. I82'-I85.0 31 1 (1 (1I 78~2. 32Salicin. Natural. C13 H18 07- 1.4338, 26.0 33 (( Artificial. (( I.42 57 AUTHORITIES. 1 Hiibner &Geuther. 13. 305. 13 olff. A. C. P. 150. 56. 2 Chautard. 10. 483. 2 Linnemann. 18. 315. 14 Lieben. 20. 546. 25 Schwanert. 15. 466. 2 Linnemann. 18. 556. L5 Watts' Dictionary. 26E. Kopp. 2.451. 4Lilnnemann. 18. 317. 16 Malaguti. A. C. Phys. (2). 27 Cahours. A. C. Phys. (3). 5 Fittig. 12. 347. 64. 160. 14. 484. 6 f Fittig. 12. 344. 17 Watts' Dictionary. 28 Rossel. Z. F. C. 12. 561. 71 Fittig. 12. 344. 18 Gal. Z. F. C. 12. 220. 29 Piria. A. C. P. 29. 300. 8,Schwvanert. 15.464. 1 9 Baubigny. 19. 624. 30Ettling. A. C. P. 29. 310. 9 Baeyer.'18.317. 20 Baubigny. 31 Mendelejeff. 13. 20.:o Wertheim. -16.438. 21 Baubigny. 19. 624. 32 Piria. A. C. Phys. (3). 1n Williamson.'7. 551. 22 Baubigny. 44. 368. [44. 368.,12. jWolff..A.C..P..150. 56. 23Baubigny.' 8 3 Piria. A. C. Plys. (3). t5 ~ ~ ~ ~ ii...Py.() SPECIFIC GRAVITY TABLES. 171 Name. Formula. Specific Gravity. Boiling Melting Point. Point.'Saliretin. C7 H6 0 I. I I 6I, 25.0 2Saligenin. C7 H8 02. 1.1613, 25.0 1 Benzoyl hydride. C7 H6 0. 1.075. 4 ( (( o 1.038, I 5. I8o0-I83.0 5 o (( s{ I.043. 6 I.0636, o.~ I79 7 ((C 1.0499, I496. 8 ( (( (( I.0504. 9Methyl benzoyl. C8 H8 0. I.032, I5.0 198.0'0 Benzoycin. CIO H12 04. 1.228. nIsomer of benzil. C14 H1O 02. II04, I0.0 3I4-0 12 Ethyl benzhydrol ether. C15 H16 0. 1.029, 20.0 I83.0 13 Acetic (( (( C15 H14 02. 1.49, 22.0 30IO-302.0'4 Benzyl benzoate. C14 H12 02- 345.0 15 (( I.I I4, I8~5. 3030-304.0 16, cinnarnate. C15 H115 02. 305.'7 ( (( [dride. (( I.o98, I4.~'s Benzo cenanthylic anhy- C14 1118 3- I.o43. 19Benzo cinnamic C16 H12 03. I.184, 23.0 20 Benzo cuninic C17 H16 03. 1.115, 23.0 21Cuminol. C10umin H12 0. 220.0 22.9832, o.0 236.0 23 ((.9727, 13.4. 2 24 ( 97 5 I, 15. 25 Veratrol. 1. C8 H10 02. I.o86, I5.~ 2020-205.0 15.0 26 Phenyl acetate. C8 H8 02. 188.0 27 ( ( (( I.074. 200.~ 28 Benzyl (( C9 H0 O. 210.0 29 Ethyl phenyl carbonate. C9 H1o 03. I.II7, 0.0 234.0 30 Phenol. C6116 H6 I.062, 20.0 I9795. 31 (5 i.o65, i8.0 I87~-I88.o 340-35.0 32 ( 1.0627. I 84.0 33 (.o8o8, 0. } I87~6-88~I. 34.0597, 329. 87- 88 AUTHORITIES. 1 Beilstein & Seelheim. 14. n Alexeyeff. 17. 335. 23 - Kopp. 18. 765. [765. 12 Linnemlann. 18. 553. 24 Mendelejeff. 13. 7. 2Beilstein & Seelheinl. 14. 13 Linnemann. 18. 554. 25 Merck. 11. 256. 3 Chardin-Hardancourt. See I14Cannizzaro. 7. 585. 26 Scrugham. 7. 605. 26. 1 15 Kraut. A. C. P. 152. 159. 2 Boughton.. 1530. 4 Guckelberger. 1. 850. 16 Plantanlour. 28 Cannizzaro. 6. 511. 5 W lller & Liebig. See 18. 17 Scharling. 9. 630. 29 Fatianoff. 17. 477. 6 Kopp. 18. 18 Malerba. 7. 444. 30 Runge. P.A.32. 308. [195 7 Kopp. 18. 19 Gerhardt. 5. 449. 31 Laurent. A. C. Phys. (3). 3. 8 endelejeff. 13. 7. 20 Gerhardt. 5. 448. [12. 391. 32 Scrugham. C. S. J. 7. 237. 9 Friedel. 10. 270. 21 Gerhardt & Cahours. C. R. 33 Kopp. 18. 10 Berthelot. 6. 455. 22 Ko)pp 18. 3a Kopp. 18. 172 SPECIFIC GRAVITY TAIBLES. Boiling Melting Name. Formula. Specific Gravity. Poiling Metin' Phenol. C6 H6 0. I.o5 54. i87.~ s. —IS.~ 2,,,, I.o68. I86~-I87.~ 3 (( ((.o667, 38.0 183.0 3705. 4Kresol. C7 H8 0. I.033, 23.- I98.~ 5 ( (( 198.0 35.0 6Metakresol. ( I89~-I9 0.~ S.-38.0 7 Parakresol. ( I97.~ 36.~ s. 34.0 8 (( (( 2I 20I? 5-202. 34. 5. 9 Benzyl alcohol. C7 H8 O. I.o59. 204.0 10 1.0628, 0.0 206?5. 11 I.0507, 15.4.f 751.4 m. m. 12 I.0465, I9.0 206.2. 13 Anisol. C7 H8 0..991, 15.~ I52.0 4 Phenetol. C8 11 0. I75.0 s 15 (( Less than water. I72.0 ]6 Ethyl phenol. C8 H,1 0. 211 470-48.0 17 Xylenol. Phloretol. C8 H, 0. I.0374, I 2. a. 220.0 18 ", Alpha. (.9709, 8 I.~ 213?5. 7 5.0 19,, Beta. O I.036, o.0 2 20 8.9700, 81 I.~ 2. 21,, Xenol. (( I.0233, 22. 2 I4~2. 22CEthyl kresol. C9 H12 0..8744, o.0 I88.0 23 Isopropyl phenate. C9 H12 O..958, o.~ 24.947, I2? 5- 76.0 25 Styrolyl ethyl ether. C10 H14 0..93I, 2I?9. I850~-87.0 26 Thymol, of Ajowan oil. CsO H14 0. I.0285. S. distils 222.0 440 27 o Cymyl alcohol. ( 243.0 28 Isobutyl anisol..9388, I6.0 I98.~ 29 Phenamylol. C,, H16 O. 2240-225.0 30Methyl thymol. C,, H16 O..941, I8.0 205.0 31 Carvol. C,1 H14 0..953, I5.0 225~-230.0 32Geraniol. C 18 0 885i, I5.0 232233. 33 8813, 2I 232-233 AUTHORITIES. 1 Duclos. A. C. P. 109. 135. 13 Cahours. 2. 403. 23 f Silva. Z. F. C. 13. 250. 2 Church. C. S. J. 16.76. 14 Baly. A. C. P. 70. 269. 24 (Silva. Z. F. C. 13. 250. 3 Graebe. 15 Cahours. 2. 425. 25 Thorpe. 22. 412. 4 v. Rad. 22. 448. 16 Fittig & Kiesow. A. C. P. 26fi Stenhouse. 9. 624. 5 Fuchs. Z. F. C. 13. 171. 156. 254. 27 Kraut. A. C. P. 92. 66. 6 Barth. Z. F. C. 13. 624. 17 Hlasiwetz. 10. 329. 28 Riess. C. S.. J. 24. 221. 7 Barth. Z. F. C. 13. 624. 18 ( urtz. 21. 460. 29 Cahours. C. R. 32. 61. 8 Wurtz. Z. F. C. 13. 382. 19 Wurtz. 21.460. 30 Engelhardt & Latschinoff. 9 Cannizzaro. 7. 585. 20 (Wurtz. 21. 460. 22. 466. 10 Kopp. 18. 21 Wroblevsky. 21.459. 31 VoLckel. 6. 512. Ii Kopp. 18. 92 Fuchs. 22. 457. 3 Jacobsen. Z. F. C. 14. 171. 12 Kraut. A. C. P. 152. 134. 33 Jacobsen. Z. F. C. 14.171. SPECIFlC GRAVITY TABLES. 173 Boiling Melting Name. Formula. Specific Gravity. Boiling MPoint ICajeputene hydrate. C10 H18 0..903, I 7.0 I75.~ 2Cinacrol. C0O H18 02. I.05-I.I5. a. 250.0 3Colophonone. C,, H18..84. 97.0 4Ericinol. C10 H16 0..874, 20.0 2400~-242.0 5 Oil Mentha Pulegium. CI0 H16 0..9271, —.939~ I82~-I85.~ 6 Geraniol ether. C20 H34 0. I870-190.~ 7 Cardol. C21 H3102..978, 23.0 8 IvaoI. C26 H40 O..9346, I 5.~ 9Terpinol. C20 H34, O..852. 168.0'0 Eucalyptol. C12 H120..905, 8.0 I75.0 "1CSafrol. CO H1002- I.II4I, 0.0 23I~-233~0'12 Kreosol. C8 H10 02- I.o894, 13.0 2 I9.0 13 Cholesterine. C2, H44 O. I.03, Melted. I69~-I70.0 14 Santonin. C15 H,18 O. 1.247, 2005. I350-I36.0 15 Cochlearin. C6CH1402.(?) 1.248. 45.0 16 Picrolichenin. 1.176.'7 Calophyllum Resin. C14 Hs 04. I.2, Cryst. I05. S. 90.~ 18 Antiar Resin. C16 H112,. 1.032. 19 Guyaquillite. C20 H26 603. I.092. 20 Hartin. C20 H34 02. I. I I5, 19.0 21 0.~ 21 From wormseed oil. C12 H1120 O..919, 20. I74~-I75.0 22 (( Angostura bark. C13 H24 O..934. a. 266.0 "2 Oil of wormwood. C0 H16 0..973, 24.0 200~-205.0 24 From oil of Osmitopsis asteriscoides. C1O H18 O..92I. I78~-I88.~ 25 Oil of Coriander. C10 H18 O..871, I4-0 I50.~ 26 (( Ginger. C0 H138 05.-.893. 246.0 27( ( Pulegium micranthum. C10 H16 0..932, I7.0 227.0 28 Aldisol. C6 H1603.(?).877, 15.0 130.0 29 Xanthil. C4 H2003.(?).894. I30.0 30 Furfurol. Cs H14 02. I62.0 31 o o I.I648, 1506. I62~8-I63~3 32 (( I.636, 135. I 66.0 AUTHORITIES. I Schnmidl. 13. 480. 12 Hlasiwetz. A. C. P. 106.354. 22 Herzog. 11.444. 2 Hirzel. Watts' Dictionary. 13 Hein. 1.920. 23Leblanc. A.C. P. 56 357. Schiel. 13. 489. 14Trommsdorf. A. C. P. 11. 24 Gorup-Besanez. 7. 596. 4Frohde. J. F. P. 82. 186. 190. 25 Kawalier. 5. 64. 5 Watts' Dictionary. 15 Watts' Dictionary. 26 Papousek. 5. 624. 6 Jacobsen. Z. F. C. 14. 171. 16i Alms. A. C. P. 1. 61. 27 Butlerow. 7.595. 7Stiideler. 1.577. [13. 618. 17 Levy. C. R. 18. 244. 28 Robiquet. Watts' Dict. 8 Planta-Reichenau. Z. F. C. 18 Mulder. A. C. P. 28.-307. 29 Cou6rbe. 9 List. 1. 726. 19 Dana's IMineralogy. 30 Cahours. 1. 733. 10 Cloiz. Z. F. C. 13. 319. 20 Schr5tter. P. A. 59. 45. 31 Stenhouse. 1. 732. 11 Grimaux & Ruotte. Z. F. 21 V6lckel. 6. 513. 32 Stenlhouse. 3. 513. C. 12. 411. 174 SPECIFIC GRA VITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Point. Point.'Furfurol. C5 H4 02. 1.168, 15.5. 1616. 2 ((((~~~~~~I 1I34, 5 2,~34 ( I 50t5. 160~-I80.~ (C I 1.50, 4Fucusol. C5 H10 02. 1.150, 1305. I7I~-I72.0 5Guajol. C9 H1402..871, 15.0 II5~-I 20. 6 Guajacol. 1.II7I, 13.- 2I0.0 7 I. 1.119, 22.0 2I0.0 8 0 1.125, I6.0 2030-205.0 9 ( eI.I I9, I7-5. 10 Kapnomor..9775, 20.-~ 85.0 11.-.995, 15-5. 12 Kreosote. I.037, 20.~ 203.0 13 (1 I.076, I 55. 14 1.04, 11.5la15 1.0 57, I3.~ 202~-2 IO.C 16 I1.0831, I7.5. 17, E1.o874, 20.~ I95.~ 18 ( 1.087, 16.0 19 Mesitene. C6H2403.(?).808. 63.0 20 Xylite..8 6. 6i~5. 21,,.805. 601o62.0 AUTHORITIES. 1 Fownes. P. T. 1845. 253. 9 Gorup-Besanez. 16 Gorup-Besanez. 20.683. 2 ( Vlcekel. 5. 652. 10 Reichenbach. J. F. P. 1.6. 17 Frisch. 20. 689. 3 [ V61ckel. 5. 652. 11 V61ckel. 6. 541. 18 Biechele. 4Stenhouse. 3. 513. 12Reichenbach. Schweig. J. 19 Weidmann & Schweitzer. 5 V61ckel. 7.611. 66. 308. A. C. P. 36. 305. 6 Hlasiwetz. A. C. P. 106. 13 Vblckel. 6.-542. b2 Weidmann & Schweitzer. 366. 14 Gorup-Besanez. 6. 542. A. C.. 36. 305. 7Sobrero. Watts' Dictionary. 5 Gorup-Besanez. 8. 63. 6. 61ckel. 4. 499. 8 V61ckel. 7. 610. SrL~CIFIC GA- Vli'Y TABLES. 17 XLI. COMPOUNDS CONTAINING C, H,. ND N. 1st. CYANIDES OF THE ETHYL SERIES.* NITRILES. Boiling Melting Name. Formula. Specific Gravity. Poiling Metint.' Methyl cyanide. C H3. Cy. 77.0 23 ".8347, o.~0 cc (( (1 0.8i9i, 16.oj 70'99-7221. 4 ( O (( 770-78.0 c5 (( c(( (( 77~6. 6 ( ( 77~-78.~ 7 (( (( (( 8 I ~-8 2. 8 Ethyl 02 H5. Cy..787, I5.- 82.0 9 (( ( (.7889, 12~6. 88.0 10,( O O 970-98.0 1, (1 6 96.7. 12 (1 c( 98.0 13 Propyl " C3 H7. Cy..795, I2~5. II8~ 5. 14 ( ( iso. ( a. 8o.0 1' Butyl o0 C4 H9. Cy..8io. I 125.0 16 ( ((.813, 15.0 125~-I28.0 17 (( ((.8164, o.~ 140 4. T Amnl yl C,5 H11,. Cy..8o6I, 20. I146.~ 19 Heptyl o C7 H15. Cy..8201, 133.- I94'-I95.~ 20OCtyl C8 H, Cy..8I87, I4.~ 200.0 2d. AMINES OF THE ETHYL SERIES. Name. Formula. Specific Gravity. Boiling Point. Name. Point. Point. 21 Dimethylamine. C H N. -IO, to-I 5.0 22 ( 1 80-9." 23 Ethylamine. C02 H7 N..6964, 8.0 I8~7. AUTHORITIES. Dumas. 1.592. 9 Frankland & Kolbe. 1.552. 17 Lieben & Rossi. A. C. P. 2 ( Kopp. 18. lo Limpricht. 9. 514. 158. 137. 3 Kopp. 18. [508. " Gautier. 21. 631. 18 Frankland & Kolbe. 1.559. 4 Buckton & Hofmann. 9. 12 Grimm. 19 Felletr. 21. 634. 5Engler. 18. 310. 13 Dunas. 1.594. 20 Felletdr. 21. 634. 6 Siersch. 21. 681. 14 Markownikoff. 18. 38. 21 Petersen. 10. 382. 7Gautier. 21.630. " Scehlieper. A. C. P. 59.15. 22 Hofmann. Watts' Diet. s Pelouze. Watts' Diet. 16 Guekelberger. 1. 852. 23 Wurtz. 3. 446. * Compare these cyanides with the carbylamines. 176 SPECIFIC GRAVITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. ITrimethylamine. C3 H9 N. 9.0 2 Propylamine. 49~7. 3 ( ((.7283, 0.~ ) 49-50.~0 4 ss ((.7I34, 2I.0 76i m. m. 5 (( iso. (.690, i8.~ 31I5. 6, iso. ( 3IO-32~5. 7Diethylamine. C4 H,, N. 57.0 8Butylamine. C4 H,, N. 690-70.0 9 (.7553, -o 7595~ 10.7333, 26.0 740 m. m. 1' Amylamine. C5 H13 N. 93.0 12.7503, I8.~ 9513 c(.8I5, o.0 95.0 14 iso..( 755, o.~ 78~5. 5Di- isopropylamine. C6 H15 N..722, 22.~ 8395-84~0'6lHexylamine. C6 Hl5 N..768, I7.0 1250~-28.~ 17 Heptylamine. C7 H17 N., I44-I48.0 is I450-I47.0 19 Methylethylamylamine. C8 H19 N. I35.0 20 Octylamine. Cs H,9 N..786. i64.0 21 ((I72-I750 22 (( I75-. z23,Ci68o-i72.0 24 Diethylamylamine. C9 H11 N. I54.0 25 Nonylamine. C9 H21 N. I900-I92.~0 26 Diamylamine. C1O H23 N. I70.0 27.(( 7825, o.O I78~-I8o0. 28 Triamylamine. C15 H33 N. 257.0 29 Tricetylamine. C48 Hss N. 39.0 s. 33.0 AUTHORITIES. 1 Hofmann. Watts' Dict. 11 Brazier & Gossleth. 3.398. 21 Cahours. 7. 484. 2 Mendius. 15. 326. 12 WVurtz. 3. 451. 22 Bouis. 8. 526. 3 { Silva. Z. F. C. 12. 638. 13 Wurtz. 19. 425. 23 Pelouze and Cahours. 16 4l Silva. Z. F. C. 12. 638. 14 Wurtz. 19. 425. 529. 5 Siersch. 21. 682. 15 Siersch. 21. 682. 24 Hofmann. 4. 489. 6 Gautier. A. C. P. 149. 159. 16 Pelouze and Cahours. 16.25 Pelouze and Cahours. 16. 7 Hofmann. 4. 489. 527. 529. 8 Wurtz. A. C. P. 93. 124. 17 Pelouze and Cahours. 16. 26 Hofmann. 4. 493. 9 Lieben & Rossi. A.C.P. 528. 27Silva. Z. F. C. 10. 157. 93. 124. 18 Schorlemmer. 16. 533. 28 Hofmann. 4. 493. o1 Lieben & Rossi. A. C. P. 19 Hofmann. C. S. J. 4. 317. 29 Fridau. A. C. P. 83. 25. 93. 124. 20 Squire. 7. 485. SPECIFIC GRATVITY TABLES. 177 3d. BASES OF THE ANILINE SERIES. Name. Formula. Boiling Melting Name. Formula. Specific Gravity. Poiling Metin'Phenylamine. Aniline. C6 H7 N. I. 020; 16.~ I82.~ 2 ( ( 1.028. 228.0 (( (( (( 1.0361, 0.~ 184.8. a4 (((C( I.0251, I37. 84 05 0( (( 1 I.oi8, 15~5- I84 5. 6 Toluidine. Benzylamine. C7 H9 N. I98.0 7 (.990, 14.0 183.~ 8 (( CC 2050-206.~ 45.0 9,, Pseudo. ( I.0002, I6~3. I98.0 10 I(( ( 1.003, 20~2. 199.0,11, Different ((.998, 2595. I99. 12 (( preparations. 2( 200. 45. 13 ((t C({ I.002, 22.0 199.0 M4 Methyl aniline. C7 H9 N. I92.0'5 Xylidine. C8 Hn, N..98 5, 80 5. 2I6. 16,, Alpha..97 5, 22.~ 2I30~-2I4. ~ 17 Beta. ((.983, 22.0 2I0o-211.0~ 1s Ethyl aniline. C8 HI, N..954, I8.0 204.0 19 Cumidine. C9 H,3 N..8526. 225.0 0 Ethyl toluidine. C9 H13 N..939I, I505. 2I7.0 21 Cymidine. C10. H15 N. Less than water. a. 250.0 22 Diethyl aniline. C10 H15 N..939, i8.~ 213~5. 23 Amyl Cll H17 N; 258.~ 24 Diethyl toluidine. Cll H17 N..9242, I5~5. 229.0 25 Ethyl amyl aniline. C13 H21 N. 262.0 26Diamyl (( C16 H27 N. 2750~-280.0 27 Cetyl (( C22 H39 N. 42.~ s. 28. 28Dibenzylamine. C14 H1s N..o033, I4.0 29Allyl aniline. C9 H1, N..982, 25.~ 208~-209.0 AUTHORITIES.' Hofmann. A. C. P. 47.50. j1 Beilstein & Kuhlberg. Z. 18 Hofmnann. 2. 398. 2 Fritsche. J. F. P. 20. 453. F. C. 12. 523. 19 Nicholson. 1. 664. 3 { Kopp. 18. 1 12 Beilstein & Kuhlberg. Z. 20 Morley & Abel. 4. 497. 4 Kopp. 18. F. &. 12. 523. 21 Barlow. 8. 547. 5Staideler and Arndt. 17. 13 Beilstein & Kuhlberg. Z. 22 Hofmnann. 2. 399. 425. F. C. 12. 524. 23 Hofnmann. 2. 401. 6 Muspratt & Hofmann. 14Hofmnann. 2. 400. [418. 24 Morley & Abel. 7. 498. 7 Limpricht. 20. 510. 15 Tawildarow. Z. F. C. 13. 25 Hofmann. 2. 401. 8 Staideler. J. F. P. 96. 67. 16 IBeilstein and Kuhlberg. 26 Hofmann. 2.401. 9 Rosenstiehl. 21. 745. A. C. P. 156. 206. 27 Fridau. A. C. P. 83. 30. 10 Beilstein & Kuhlberg. Z. 17 Beilstein and Kuhlberg. 28 Limpricht. 20. 510. F. C. 12. 523. [ A. C. P. 156. 206. 29 Schiff. 17. 415. 178 SPECIFIC GRA VITY TABLES. 4th. BASES OF THE PYRIDINE SERIES. _Name. ~~~~~~Boiling Melting Name. Formula. Specific Gravity. Poiling Metin 1 Pyridine. C5 H5 N..9858, o.~ I I67. 2.924, 22.~ I 5.0 3 ( ((5. 4Picoline. C6 H7 N. -955, IO.~ 133.0 5.96I3, o.' 135.0 6.933, 22.0 134.0 (( (( I35.0 7 I35-0 8 I3 5. Parapicoline. ( I1.o77. 2600-3I5.0'0Lutidine. C7 H9 N..928. I77~-I83.~ 11 ~( (".9467, o.0 I54 5. 12.945, 22-0 154.0 13 ( Alpha. ((.9467,.~ 154.0 14 (( Beta..9555, 0.~ I63~-I68.~ 5 Collidine. C8 HI, N..92I. I79.0 16 ((79.~ 17.9439, O-~ I80.0 18 I 80.0 19.953, 22.0 170.0 20 I78- I80.0 21 Parvoline. C9 H13 N..966, 22.~ I88.~ 22 Coridine. (CO H15 N. *974,22. 21 I.0 23 Rubidine. CH1 H17 N. 1.O17, 22.0 230.0 24 Viridine. C12 H19 N. 1.024, 22.~ 251.~ 5th. MISCELLANEOUS COMPOUNDS. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 2M 1Iethyl carbylarnine. C2 H3 N. 580-59.0 26 Ethvyl (( C3 H5 N. 780-80.0 27 Isopropyl ( C4 H7 N..7596, o.~ 87.0 28 Butyl (( C5 H9 N..7873, 4.0 II4~-I I70 AUTHORITIES. 1 Anderson. 10. 397. 11 Anderson. 10. 397. 20 Baeyer. Z. F. C. 12. 689. 2 Thenius. 14. 502. 12 Thenius. 14. 502. 21 Thenius. 14. 502. 3 Church & Owen. 13. 359. 13 rWilliams. 17.437. 22 Thenius. 14. 502. 4 Anderson. A. C. P. 60. 93. 14 Williams. 17.437. 23 Thenius. 14. 502. 5 Anderson. 10. 397. 15 Anderson. 7. 490. [309. 24 Thenius. 14. 502. 6 Thenius. 14. 502. 16 Williams. Chem. Gaz. 13. 25 Gautier. 20. 367. 7 Church & Owen. 13. 359. 17 Anderson. 10. 397. 26 Gautier. 20.367. 8 Baeyer. 18 Church & Owen. 13. 359. 27 Gautier. B. S. C. 11. 224. 9 Anderson. 10. 396. 19 Thenius. 14. 502. 28 Gautier. Z F. C. 12.415. 10 Williams. 7. 494. SPECIFIC GRAVITY TABLES. 179.Boiling Melting Name. Formula. Specific Gravity. Point. Melting Point. Point.'Acetylamine. (?) C2 H5 N..975, 15.0 21 8. 2Allylamine. C3 H7 N..864, I5.~ 58.~ 3 Ethylene cyanide. C H N2 I.023, 45.0 37-0 4Allyl H C4 H5 N..8389, I12.~ II8~7-II9~2. { (.812, 0.0 } 6.794, I7. 9 6. 8(( o( (.8491, 0.0 I 6~-118.~ 8 (C.835 i, i56o-ii8.0 9Phenyl C7 H5 N. I.0073, I5.0 I900~-I9I.~ 10 1.0230, 0.0 ) I90~6. 11 C ( (. I.oo84, 1698. 12 Cumonitrile. C1, H1l N..765, I4.0 239.0 13 Chinoline. C9 H7 N. i.o8I, Io.0 239.0 14 (C 2380-243.0'5Lepidine. C10 H9 N. I.072, I5.~ 266~-27I.~'6 Pyrrol. C4 H5 N. I.077. 133.0 17 Coniine. C H N..89. I87~5. s18 (( 89.0 19 2I2.0 20.878. I68~-I7I.~ (( (( 16305. 22 Nicotine. C5 H7 N. I.033, 4.~ 23 (( 1.027, I 5.0 24 1.0I 8, 30.0 25 1.ooo6, 5o.0 26 CC.9424, I O 10 5 AUTHORITIES. 1 Natanson. 9. 527. 9Fellling. A. C. P. 49. 91. I1 Christison. Watts' Dict. 20eser. 18. 506. 10J Kopp. 18. 9 Ortigosa. A. C. P. 42. 313. 3Simpson. 14.654. 1 I Kopp. 18. 20 Blyth. 2. 388. 4 Will & K6rner. 16. 499. 12 Hofmann. 1.595. 21 Wertheim. 15. 364. 5 Lieke. A. C. P. 112. 319. 13 Hofmann. A. C. P. 47.79. 22 Barral. 1.614. 6 Lieke. A. C. P. 112. 319. 14Willianls. 9. 533. 23 Barral. 1.614. 7 ( Rinne & Tollens. A. C. 15 Williams. 9. 536. 24 Barral. 1. 614. P. 159. 105. 16Anderson. 10. 399. 23 Barral. 1.614. 8 Rinne & Tollens. A. C. 17 Geiger. Watts' Dictionary. 26 Barral. 1. 614. P. 159. 105. 180 SPECIFIC GRAVITY TABLES. XLII. COMPOUNDS CONTAINING C, H, N, AND 0. 1st. NITRITES AND NITRATES OF THE ETHYL SERIES. Name. Formula. Specific Boiling Melting Gravity. Point. Point.' Methyl nitrite. C H3 N O..991. — I2.0 2 Ethyl C2 Hs N 0,..886, 4.0 3.947, I5.0 16~4. 4 (1.898. I75-_I8.o a5 goo.900, 15.5. I6~6-I7~8. 6Isopropyl,t C3 H7 N 0.856, O. 45-0 7.844, 24.- 762 m. m. 8Butyl c, C4 H9 N 02-.89445, 0. (( (.877 I, I6.~ 67.0 19 (C.82568, 50.0 11 Amyl (( C Hi N 03. 96.Q 1 ((.8773. 9I.~ 13 ( (( 99.0 14 Methyl nitrate. C H3N 013. 1.182, 20.0 66.0 " Ethyl (( C3 H5 N O3- I.112, I7.0 85.0 16 (~ (~ 20?6~,(( ~~ ~~,, I.I322, 0.~ 863 17 (( (( 1.1123, 155. J5 1S i (( I.o948, I7.0 87?2. "' Isopropyl ( C3 H7 N O3. I.-054, 0o.~ IOI~-I02. 20 ( I.036, I9. 76o m. m. 21 Butyl (c C4 H N 03. a. I30.0 22( c (( I.o384, o.O I23. cc23 ( c cc 1.020, I 6.~ "2Amyl C5 H, N 03-.902, 22.0 I37.~ 25 (" ((.994, IO.0 148.0 36 ~ { 1.000, 7~-8.0 I47~I48.~ AUTHORITIES. 1 Strecker. 7. 521. l0 f Chapman & Smith. C. S. 18 Wittstein. 18. 470. 2Dumas & Boullay. A. C.. J. 22.153. [12. 319. f9 Silva. Z. F. C. 12. 637. Phys. (2). 37.19. 1 Balard. A. C. Phys. (3). 20 Silva. Z. F. C. 12. 637. 3 Liebig. A. C. P. 30. 143. 12 Rieckher. 1. 699. 21 Wurtz. 7. 575. 4 Mohr. 7. 561. 13 Guthrie. 11. 403. 22 (Chapman & Smith. C. S. 5 Brown. 9. 575. 14 Dumas & Peligot. A. C. J. 22. 153. 6 j Silva. Z. F. C. 12. 637. Phys. (2). 58. 39. 23 Chapman & Smith. C. S. 7 Silva. Z. F. C. 12. 637. 15 Millon. A. C. Phys. (3).(3). J. 22.153. 8 Chapman & Smith. C. S. 8. 236. 4 Rieckher. 1. 699. J. 22. 153. [J. 22. 153. 16 Kopp. 18. 25 Hofmann. 1. 699. 9 Chapman & Smith. C.S. 17 Kopp. 18. 26 Chapman & Smith. 20.550. SPECIFIC GRA VITY TABLES. 181 2d. NITRO-SUBSTITUTION COMPOUNDS. Name. Formula. Specific Boiling Melting Gravity. Point. Point.'Nitro caprylic acid. C8 H15 N 04. I.093, I8.0 2 Ethyl nitro caprylate. C10 H19 N 04 I.031 I,8.0 3 (( nitro lactate. C5 H9 N 05. i.1534, I3-0 178.~ 4 (( nitro malate. C8 H13 N 7. 1I.2024, I6.0 5 nitro tartrate. CsH12 N2,10 1.2778, melted. 450-46.~0 6Nitro glycerine. C3 H5 N3 09. I.595,-I.60, I5.0 7 I-.5958. 8 i.60. 9 i.6o. 9((( 1.60. 0 Nitroso diethyline. C4 H10 N2 0..95I, I7~5. 17699. 11 Methyl nitrobenzoate. C8 H7 N 04. 279.0 70.0 12 Ethyl C9 H9 N 04. 298.0 42.0'3 Nitrobenzol. C6 H5 N O,. 1.209, I5.0 2I3.0 s. 3.0 14 1.2002, 0.0 ).O02 15 I866, I44 2I9-220.'6Nitrotoluo1. C7 H7 N 02. I.I8, 16~5.~ 225.17 o Ortho. (( i.i68, 22.0 230~-23I.~ 198 ( Meta. 1.163, 2395. 2220o223 0,((~ ((,~.162, 23.0. 20Nitroxylol. Beta. C8 H9 N 02. 1.126, I795. 2370~-239.~ 2.~0 z21 0 1 1.126, 2405. 2270~-228.0 22 Alpha. (( I.124, 25.0 245~-246.~ 23 Dinitro benzol. C6 H4 N2 04. 87.0 24 Dinitro aniline. C6 H5 N3 04. I75.0 25 Mor1o nitro methyl phenol. C7 H7 N 03. 1.249, 26.0 265.~ 9.0rs. o.0 26 Nitro isobutylanisol. Para. C10 H13 N 0s. I I36I, 20.0 275~-280.0 27 (( (( Ortho. ( I. I046, 20.0 2850-290.0 28 Nitroethane. C2 H5 N 0,. 1.0582, 13.0 I 13~-I I4.0 Isomer of ethyl nitrite. AUTHORITIES. 1 Wirz. A. C. P. 104. 289. 13 Mitscherlich. P. A. 31. 20 Tawildarow. Z. F. C. 13. 2 Wirz. A. C. P. 104. 290. 625. 418. [41.'. 3 L. Henry. Z. F. C. 13. 692. 14 Kopp. 18. 21 Beilstein & Kuhlbrg. 22. 4 L. Henry. Z. F. C. 13.692. 15 { Kopp. 18. 22 Beilstein & Kuhlberg. 22. 5 L. Henry. Z. F. C. 13. 692. 16 Deville. A. C. Phys. (3). 415. 6 De Vrij. 8. 626. 3. 175. 23 Rudnew. Z. F. C. 14. 202. 7Liebe. 13. 453. 17 Beilstein & Kuhlberg. 22. 24 Rudnew. Z. F. C. 14. 202. 8 Sobrero. 13. 453. 403. 25 Brunck. 20. 619. 9 Champion. Z. F. C. 14.350. 18 Beilstein & Kuhlberg. A. 26 Riess. Z. F. C. 14.39. 10 Geuther. 16. 409. C. P. 155. 17. 27 Riess. Z. F. C. 14. 39. 1Chancel. 2. 327. 19 Beilstein &Kuhlberg. A. 28sMever and Stuber. A. C. 12 Chancel. 2. 327. ( C. P. 155. 17. Phys. (4). 28.138. 182 SPECIFIC GRA VITY TABLES. 3d. MISCELLANEOUS COMPOUNDS. Name. Formula. Specific Boiling Melting Gravity. Point. Point. Methyl cyanate. C2 H3 N 0. a. 40.~ 2Ethyl ((C3 H15 N 0..898I. 60.~ 3 Amyl ( C6 H1 N 0. a. I00.0 4Alyl ( C4 1H5 N 0. 82.0 5 Phenyl C7 H15 N 0. 1.092, 50.~ 163.0 6Methyl cyanurate. C6 1H9 N3 0.3 274.0 I75o-I76. 7Ethyl (( C9 H15 N3 03. 253.0 95.0 98Aceto-ethyl nitrate. C6 H14 N2 07 I.0451, I9.~ 840-86.0 9 Valeracetonitrile. C26 H48 N4 0..79 680-70.0'0 Trioxamylidene. C15 H33 N 03..879, 22.~'1Cyanetholine. C3 H5 N O. I.127I, 15.~ 12 Acetamide. C2 H5 N 0. 1.11I-.13, I4.0 13 Ethyl formamide. C3 H7 N 0..967, 2.0 199.0 14 (( acetamide. C4 Hg N 0..942, 405~ 205.0 15 " diacetamide. C6 Hn N O. 1.0092, 20.0 I850-I92.0'6Mucamide. s. C6 12 N2 06. 1.589, 13?5. 17 Acetanilide. s. C8 H9 N O,. I.099, Io~5. 295.0 101.0 18 Urethane.. C3 H7 N 0.2.9862, 21.~'9 Ethyl urethane. C5 H1, N 02..9862, 2.~ I74~-I75.~ 20 Asparagine. C4H8N203. H20 I.519, I4.0 21 Aspartic acid. Active. C4 H7 N 04. i.6613. 22 (( (( Inactive., 1.6632. 23 Hippuric acid. s. C9 IT9 N 03. 1.308. 24 Ethyl hippurate. s. C H,3 N 03. I.043, 23.0 44.~0s. 32. 25Urea. C H4 N,2 0. 1.30, I2.0 26 (( ( I 35. 27 ( (5 1.35. 28 Benzoyl hydride hydrocyanate. C8 H7 N 0. 1.124. d. I70.~ 29 Mono amido methyl phenol. C7 H9 N 0. i.Io8, 26.0 2I6.0 30 -? C6 H, N2 0..924, 14~ 2000-205.~ AUTHORITIES. l Wurtz. 7. 568. n1 Cloez. 10. 386. 20 Watts' Dictionary. 2 Wurtz. 7.564.'2Mendius. 26. 21 J Pasteur. 4. 389. 3 Wurtz. 2. 428. 13 Wurtz. 7. 567. 22 Pasteur. 4. 389. 4 Hofmann & Cahours. 9. l4Wurtz. 7. 566. 23 Schabus. 3. 410. 586. 15 Wurtz. A. C. Phys. (2). 42. 24 Stenhouse. A. C. P. 31. 148. 5 Hofmann. 55. 25 Bideker. 26. 6 Wurtz. 7. 568. 16 Malaguti. C. R. 22. 854. 26 Proust. 7 Wurtz. 7. 567. 17 Williams. 17. 424. 27 Schabus. 8 Nadler. 13. 403. 18 Weltzien's "Zusanmen- 2S V6lckel. P. A. 62. 444. 9 Schlieper. A. C. P. 49.19. stellung." 2 Brunck. 20.620. 10 J. Erdmann. 17. 419. 19 CWurtz. 7. 565. 30Siersch. 20. 537. SPECIFIC GRAVITY TABLES. 183 Specific Boiling Melting Gravity. Point. Point.'Cyanoil. C6 H N 0O. (?) I.oo. 2Nitroxyl piperidine. C5 H,0 N2 0 I.o659, 15?5. 240.~ p. d. 3Piperine. C1, H19 N 03. I.I931, 18.~ 1000+. 4 Caffeine. C8H1ON402. H20 1.23, I9.0 5 Subl. I84~7. I77~8. 6Creatine hydrate. C4HS302. H20. 1 34-1I35 7 Codeine. C18H21NO3. H1O0 1.300. s 8Morphia butyrate. C42 154 N2 010 I.2I5, I3.0 9,, oxalate. C361H38N209,.2aq. 1.286, 15.0 10 ( lactate. C40 H50 N2 0,2. 1.3574. " Indigo blue. C5 H5 N 0. I.35. XLIII. METALLIC SALTS OF ORGANIC ACIDS. ~Name. Formula. ~ Specific Boiling Melting Gravity. Point. Point. 12 Lead formate. Pb C2 H2 04. 4.56, I I. 13Copper (( Cu C2 H2 04. 2 aq. 1I.8I5, 20.0'4Sodium acetate. Na C2 113 0. 1.421, I4.0 15 6, (( Na C2 H3 06 aq. a 1.420. 16 0( < ze' I.40, I2.0 "Silver (( Ag C2 H3 0~. 3.I28. 10 Lead (( Pb (C2 H3 2) 2.3 aq. 2.496. 19 Barium (( Ba(C2H02)2 H20. 2.19, 13~. 20 Copper (( I1.9I4, 20.~0 21 Zinc (( Zn(C2H302)2. 3 aq. 1.7I75, 12.0 22 Sodio uranic acetate. Na C2 H3 0. 2.55, I2.0 23(( ~ (( 2 (U C,2 H303 ). 24 Cupro calcium I.4206. 25Potassium oxalate. K2 C2 04. 12 0. 2.I04, m. of 2. 26 (C 2.o8. AUTHORITIES. 1 Rossignon. A. C. P. 44. 301. 11 Weltzien's " Zusammen- 19 B6deker. 26. 2 Wertheim. 16. 440. stellung." 20 Gehlilen. A. C. Phys. (1). a Wackenroder. Watts' Dict. 12 B6deker & Giesecke. 26. 83. 213. 4Pfaff. Watts' Dictionary. 11 Gehlen. A. C. Phys. (1). 21 lB6deker. 26. 5 Mulder. P.A. 43.175. 83. 213. 22 ( Bodeker & Giesecke. 26. 6 Watts' Dictionary. 14 B6deker. 26. 23 B6deker & Giesecke. 26. 7Hunt. 8.566. 5 Buignet. 14.15. 24 Schabus. 3. 393. 8 Decharme. 16. 445. 1I B6deker. 26. 25Playfair and Joule. 11. 9 Decharme. 16. 445. 17 Liebig & Redtenbacher. 26 Schiff. 12. 16. 0 Decharme. 16. 445. 18 Buignet. 14. 15. 184 SPECIFIC GRAAVITY TABLES. Specific Boiling Melting Gravity. Point. Point. IAmmonium oxalate. Am2 C2 04. H2 0. 1.461, m. of 2. 2 1.4753 (( (( (.470. 4 Silver " Ag2 C2 04-. 4.96, I0. 5Thallium (( Tl2 C2 04. 6.3I. 6 Hydrogen sodium oxalate Na H C2 04.. H 2.3 5. 7'( potassium K H C2 04. I.965, m. of 2. 8 ((12.030. 9 2.088. 10 ammonium Am H C2 04. H2 0. 1.563, m. of 3. 11 ( (( ( I556 12 thallium (( T1 H C2 04. H2 0. 3.97I1 13 Potassium quadroxalate K H3 C4 08. 2 H2 0- I.8I7. 4 (( (( (( 14 (I 1.765. 15 i.836. 16 Ammonium Am H3 C4 08. H2 0. I.589, m. of 2. 17 1.607. 8 Potassium copper oxalate K Cu C40i8. 2 H2 0. 2.288, m. of 2. "A1mmonium (( A Am2CuC4O,.220. I.923. 20 Uralnium oxalate. U, 02- C, 04 3 H2 0. 2.98. 21 NWhewellite. Ca C2 04. 2.50-2.75. 22 Humboldtie. 2 Fe C2 04. 3 0. 2.3-2 2 Fe Cs 04. 3 Ha O. 2.I 3-2.489. 23 Ammonium succinate. IAn2 C4 14 04. I.367, I0. 24Silver (( Ag2 C4 H4 04- 3.5I8, I0.0 25 Lead (('Pb C4 H4 04. 3.800, IO.~ 26 Sodium tartrate. Na2 C4H406. 4 H20. I.794.'2 Potassiulm ((,K2 C4 H4 06. 1.975. 28 (( (( K2 C4 H4 06. H2 -. I.96o. 29Ammonium tartrate. A2rl C4 H4 06-..566. 30 1( (( (( I.523. 31 Silver Ag2 C4 H4 06. 3.4321. 82 Thallium (Tl2 C4H406)2. H,20. 4.658. AUTHORITIES. Playfair and Joule. 11. 12 Lamy and Des Cloizeaux. 23 Zachariae. 26. 2 Schiff. 12. 16. " Nature." 1. 142. 24 Husemann. 26. 3Buignet. 14. 15. 13 Playfair and Joule. 11. 25 Husemann. 26. 4 Husemann. 26. 4 Schiff. 12.16. 26 Buignet. 14.15. 5 Lamy and Des Cloizeaux. 15 Buignet. 14. 15. 27 Schiff. 12. 16. " Nature." 1. 142. 16 Playfair and Joule. 11. 28s Buignet. 14. 15. 6 Buignet. 14. 15. 17 Schiff. 12. 16. 29 Schiff. 12. 16. 7 Playfair and Joule. 11. 18Playfair and Joule. 11. 30 Buignet. 14. 15. 8Schiff. 12. 16. 9 Playfair and Joule. 11. 31 Liebig & Redtenbacher. A. 9Buignet. 14. 15. 20 Ebelmen. J. F. P. 27. 391. C. P. 38. 139. ]0 Playfair and Joule. 11. 21 Dana's ]Mineralogy. 32 Lamy and Des Cloizeaux. Iu Schiff. 12. 16. 22 Dana's Mineralogy. "Nature." 1. 142. SPECiFIC GRAVITY TABLES. 185 Specific Boiling Melting Gravity. Point. Point. Hydrogen potassium tartrate. K H. C4 H4 06. I.943. 2 U( o( (( 1.973. 3 Io ( ~ ( 1.956. 4 ammonium o Am H. C4 H14 06..68o. 5 ((thallium (, T1 H. C4 H4 06. 3.496. " Sodium potassium,, Na K. C4 H4 06. 4 H, 0. I 74. 7 1.767. 8 (( o ( o( 01.790. 9 (( ammonium ( Na Am. C4H406.4H20. i.58. 10 (C (('( 1*576. 11 I.587. 2 Potassium ( (( K Am. C4 H406. 4H20. 1.700. 1" Potassium tartar emetic. (K(SbO)C4,H,406). H0. 2.5569. 14 (( (( 2.607. 15 ( (( 2.588. -6 Thallium " " (T1(SbO)C4H406),.H20. 3.99. 17 Potassium racemate. K2 C4 H4 62 H2 I.58. "ISilver Ag2 C4 H4 06. 3.7752. 19Thallium J" (T1 C4 H4 06)2,. H2 0. 4.659. 20 Racemo-emetic. (K(SbO) C4H406)2,.H20. 2.4768. 21 Silver malate. Ag, C4 H4 05. 4.00oo6. 22 Hydrogen ammonium malate. Am H. C H4 05-. 1.55. 23 Thallium picrate. T1 C6 H2 (N O2)3 0. 3.03924 Calcium hippurate. 2(CaC18H16N206).3HO. 1.318. 25 Potassium borotartrate. K B 02. C4 H4 0,. 1.832. AUTHORITIES. I Schabus. 3. 3'78. 11 Schiff. 12.16.'9 Lamy and Des Cloizeaux 2 Schiff. 12. 16. 12 Schiff. 12. 16. " Nature." 1. 142. SBuignet. 14. 15. 13Pasteur. A. C. Phys. (3). 20Pasteur. A. C. Phys. (3). 4 Schiff. 12.16. 28. 86. 28. 86. 5 Lamy and Des Cloizeaux.'14Schiff. 12.16. 2" Liebig & Redtenbacher. A. "Nature." 1. 142. 15Buignet. 14.15. C. P. 38. 139. 6 Mitscherlich. 16Lamy and Des Cloizeaux. 22 Pasteur. 4. 392. 7 Schiff. 12. 16. " Nature." 1. 142. 23 Lamy and Des Cloizeaux. s Buignet. 14. 15. 17 Mitscherlich. "Nature." 1. 142. 9 Mitscherlich. 18 Liebig& Redtenbacher. A. 24Schabus. 3. 411.'0 Pasteur. 2. 309. C. P. 38. 139. 25 Buignet. 14. 15. 13 186 SPECIFIC GRA AVITY TABLES. XLIV. COMPOUNDS CONTAINING C, H, AND C1. INCLUDING THE CHLORIDES OF CARBON PRODUCED BY SUBSTITUTION. 1st. CHLORIDES OF THE ETHYL SERIES. Name. Formula. Specific Gravity. Boiling Melting Name.ific Gai Point. Point. Methyl chloride. C H3. C1. -20~ to -22.~'Ethyl o C2 H.5 C1..874, 5.~ 12.~ 3.92I38, Io. I I.o 4 (( (( II -12. 5 CC C(.9253, o.~ 11~-I3.0 6 ( ((.9I76, 8.0 I21I8. 7 Propyl C, H7. C1. a. 40.0 8,(( (( iso. ((.874, IO.~ 360-38.0 9 C 52.0 10 (C (C (C.9156, o.0 11 (( ((.89I8, I9~75. 46 5. 12 (C.867, 39.0 13 Butyl,C4 11,. Cl. 70~-75.0 14 C.880o. 70.~0 15 (650-70.0 16 C.9074, o.O 77.6. 17 (C.8874, 20.~ 74I-3 m. m. 18.8953, o.O ( 19( ((.865I, 2708 69.0 20 Cf CC.8281, 59.0 21 Amyl, C5 H,,. C1. I02.0 22 (( (( (( I0 0 I. 23 (( ((.8859, ~ I I. (C24 ( (C ((.8625, 25.1. 25 (C.89584', 0. IoI075.0 26 iso. ((.883, o.~ 90.~0 cc 27 (( (( 98O-I03.0 AUTHORITIES.'l Berthelot. 8._ 50. Berthelot. 8.599. 1 Pierre & Puchot. A. C.19 Pierre & Puchot. A. C. 2Thinard. 4 Phys. (4). 22.281. Phys. (4). 22. 310. 3 Pierre. 15. 12 [ Pierre & Puchot. A. C. 20t Pierre & Puchot. A. C. - Schorlemmer. 17.467. Phys. (4). 22. 281. L Phys. (4). 22. 310. 5Darling. 21. 328. 13 Wurtz. 7. 572. 21 Cahours. J. F. P. 22. 172. 6 Linnemann. A. C. P. 160. 14Gerhard. 15.409. 22Balard. A. C. Phys. (3). 195. 15 Pelouze & Cahours. 16. 524. 12. 300. 7 Berthelot. 8. 613. 6 Lieben & Rossi. A. C. P. 23 Kopp. 18.:8 Linnemann. 18. 489. 158. 137. [158. 137. 24 Kopp 18. 9Chancel. 22. 359. 17 Lieben & Rossi. A.C. P. 25Pierre. 15.:f Pierrei& Puchot. A. C. 18 Pierre & Puchot. A. C. 26 Wurtz. 16. 516. Phys. (.4)..22..281.. Phys. (4). 22. 310.' 27Pelouze &Cahours. 16.524. SPECIFIC GRAVITY TABLES. 187 Name. Formula. Specific Gravity. Boiling Melting Point. Point.'Amyl chloride. C5 H,,. Cl..90I3, 0.0 ) 2 (1.8834, 20.~ io66. 3(( ( ((.868, 40.~ 739.8 m. m. (( (c (c 8750, 20.~ IOI.~ c5 ({(C ((.8777, 20.0 IOI.~ 6 Hexyl cC613. C1..892, 16.0 I250-I28.0 S7 cc Beta. 1( I20~-I30.~ 8 ((.892, 23.0 I250-I30.0 9,6 (( iso. ((.8943, 14.0 16(( (( ((.8874, 22.0-~ I22.0 11.8759, 340'2Heptyl (( C C7 H15 C.9983, 15-, I75.0 13 (C.890, 20.0 I480~-I 52.~0 15 Azelaic (( 8737, I85.5 I~-I 53-~ 1Acid...8725 20.0 16 Acid. F1 From (c.88I4, 16~5. 17 From 7 ~(( Ethyl amyl. " (.8758o, 18 I46~-148.~ ( petroleum. ((.8965, I9.0 I49.0 20.89I, I9.0 150~-I 52.~ 2" Octyl ( C H17. C1. I75-. 22 (5.892, I8. I700~-I72.0 23.895, I6.0 I680-I72.0 24 CC I620-I67.o 25 c.8802, 16.0 I79~5-I80o5. 26 0 iso..8834, I0?5.. 27 C o iso. (C.8617, 36.0 28Nonyl (( CgH19,. C1..899, I6.0 I96.0 29 Decyl (( C10 H21. C1 2000-204.~ 30 I 900-200.0 31 Dodecatyl (( C12 H25. C1.. 933, 22.0 2420~-245.0 32 Myristyl ( C14 H29- C1. 280.0 33 Cetyl (( C,6 HI-I33..84I2, 12.~ 289.0 p. d. AUTHORITIES. 1 Lieben & Rossi. A. C. P. 12 Petersen. 14. 613. 21 Bouis. 7. 582. 159. 70. [159. 70. 13 Pelouze & Cahours. 15. 386. 22 Schorlemmer. 15. 386. 2I Lieben & Rossichorlemmer. A. C. P. 23 Pelouze& Cahours. 16.528. 3 / Lieben & Rossi. A. C. P. 1 136. 257. 24 Wurtz. 16. 510. [ 159. 70. 15 Schorlemmer. A. C. P. 2 Zincke. A.C.P.152. 5. 4 f Schorlemmer. 19. 527. 136.257. [136.257. 26 Schorlenmer. 20. 567. 5 Products from two sources. 16 Schorlemnler. A. C. P. 27 Schorlemmer. 20. 567. 6 Pelouze & Cahours. 16.525. 17 *Scorlemmer. A. C. P. 28 Pelouze & Cahours. 16.529. Wanklyn and Erlenmeyer 136. 257. [136. 257. 29Pelouze & Cahours. 16.530. 17. 509. 18 Schorlemmer A. C. P. 30 Wurtz. 16. 510. sGeibel & Buff. 21. 336. 19 Schorlemmer. A. C. P. 31 Pelouze & Cahours. 16.530. 9 (Schorlemmer. 20. 567. 136.257. 32Pelouze&Cahours. 16.530. 10 Schorlemmer. 20. 567. 20 Schorlemmer. 33 Tuttsscheff. 13 406. 11 [Chlorinated di-iso-propyl.] 188 SPECIFIC GRA VITY TABLES. 2d. CHLORIDES OF THE ETHYLENE SERIES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. IMethylene chloride. C H2. C12. 400-42.0 2 (( 1.360, o.~ 39 5-40 5. 3Ethylene ( C2 H4. C1. I.256, I2.0 825. 4 ( ( C (( 86.0 5 ( (I (C 1.247, I8.0 8204. 6 a 8598. 7 (C (C (C 1.28034, o.0 84092. 8 85.0 9 (( (( 1.2562, 20.0 85.0 10 (( (( 1.26, I4.0 85.0 11 Propylene (C H6. C12- I00-0I03.0 12 (.1.151. 104.0 13 Butylene (( C4 H8. C12. I.II2, 8.0 I 23.0 14 ( ((.0953, o.O 223 15 (( ((.07 5I, 2097 1223. 16 Amylene ( C5 H10. Cl12. 1.058, 9.0 I4I~-I47.0 17 CC o( 1.2219, o.0 I45-0'8 Heptylene (( C7 H14. C12- I9I.~ 19 1 I.0295, I0.0 [Isomers of some of the above compounds may be found in the next table.] 3d. SUBSTITUTION DERIVATIVES OF THE TWO PRECEDING SERIES. Name. Formula. Specific Gravity. Boiling Melting Point. Point. 20 Chlorinated methyl chloride. C H2 C12. 1.344, 18.~ 3095. 21 Chloroform. C H C13. 70.0 22 C( (( 1.48, I 8.~ 60o8. 23 U (( I.491, I7.0 61.0 AUTHORITIES. 1Perkin. 22. 342. 9 Haagen. 32. 18 Limpricht. A. C. P. 103. 2Butlerow. 22. 343. 10 Maumen6. 22. 346. 81. 3Regnault. A. C. Phys. (2). 1 Reynolds. 3.495. 19 Husemann. 26. 58. 307. 12Cahours. 3. 496. 20 Regnault. A. C. Phys. (2). 4Dumas. A. C. Phys. (2). 1 Kolbe. 2. 338. 71.378. 48, 196. 14 f Kopp. 18. 21 Soubeiran. A. C. Phys. 5 Liebig. A. C. P. 214. 15 Kopp. 18. (2). 48. 139. 6 Despretz. 16 Guthrie. 14.665. 22 Liebig. A. C. P. 1. 199. 7Pierre. 15. 17 Bauer. 19. 531. 23 Regnault. A. C. Phys. (2). 8 Geuther. 15. 421. 71. 381. SPECIFIC GRAVITY TABLES. 189 Name. Formula. Specific Gravity. Boiling Meltin Point. Point.'Chloroform. C H C13. 1.493-I.497. 2 ((( 1I413. Two 3 (( (< 1.496, I2.~ products. 4 R(( o 1.500, 1505. 5 (c (1 I.52523, 0.0 6305. 6 6( 1.512, 12.0 7 ( z(I(.49. 8 C I1.472, I605. 9 ((o(1.507, I7.o 0 Chlorinated ethyl chloride. C2 H4 C1,. I.I74, I7.~ 64.~ 11 1 CC (c 58. 12 1 o ( cc I.24074, 0.0 6498. 13 cc E ( ( I. I 89, 43.- 59~-6.~ 14 R ( C I.I98, 605.~ 570-59.0 15 R ( (C 62.0 16Dichlorinated,, C, H3 C3,. 1.372, I6.0 75.0 17 c Cc c" 1.3465I, 0.~ 7499. 18,( 7495'9 Chlorinated ethylene chloride. C2 H3 Cl3 1.422, 17.0 I I 5. 20 ( (( (( 1.42234, 0.0 114o2. 21 Trichlorinated ethyl chloride. C, H2 C14. 1.530, 17.0 I02.0 22 Bichlorinated ethylene chloride. C, H2 C14. 1.576, I9.~0 135.0 232 6c ( 1.61158, o.~ 138~6. 24 ( (( c( I.614, O.~ I47.0 [Compare the above with acetylene tetrachloride.] 25 Pentachloro dimethyl. C, H C15. 1.663, o.0 I53.0 158.0 20 (( (( (( 1.644. I46.~ 27 (( ^ ( I.66267, o.~ 153.8. c8 cc z ( I.7I, 0.~ ) I58.~ 29 6 6 cc 1.69, 13.~f AUTHORITIES. Swan. 1.681. ix Wurtz. C. R. 45. 1015. 21 Regnault. A. C. Phys. (2).: (Soubeiran & Mialhe. 2. 12 Pierre. 15. 71. 366. [69.162. 408. [408. 13 Geuther. 11. 289. 22 Regnault. A. C. Phys. (2) 3 Soubeiran & Mialhe. 2. 14 Darling. 21. 329. 23 Pierre. 15. 4Gregory. 3. 454. 15 Staedel. Z. F. C. 14. 197. 24 Paterno & Pisali. J. F. P. 5 Pierre. 15. 16 Regnault. A. C. Phys. (2). (2). 4. 175. @ Schiff. A. C. P. 107. 63. 71. 364. 25 Regnault. See Paterno, 7 Fliickiger. 17 Pierre. 15. below. [71. 368. 8 Geuther. 18 Staedel. Z. F. C. 14. 197. 26 Regnault. A. C. Phys. (2). 9 Flickiger. Zeit. Anal. l9 Regnault. A. C. Phys. (2). 27 Pierre. 15. Chem. 5.302. [71. 357. 69. 153. 28 ( Paterno. Z. F. C. 12. 245. 0 Regnault. A. C. Phys. (2).'20Pierre. 15. 29 Paterno. Z. F. C. 12.245. 190 SPECIFIC GRA VITY TABLES. Name. Formula. Specific Gravity. Boiling Melting Name.fic Gai Point. Point. Dicarbon hexachloride. C2 C16. 1.6I9. I22.0 2 (( . Thomsen. P.A. 142. 337. ((200 ((.955 Compare in Table n955umber V. ~! Compare in Table number V. SPECIFIC HEA T TABLES. 49 Solution. Specific Heat. Authority. Sodium hydrogen sulphate. Na H S04 + 25 aq..8683. 50 (c.9I46. c (( 100 r9497 j Marignac. 42. O 200 (.9719. Potassium sulphate. K2 S04 + 200 aq..940. Thomsen. P. A. 142. 337. Ammonium sulphate. (NH4)2 S04 + 30 aq..820. c c 50 ((.87I. L 0 Thomsen. P.A. 142.337. (( (( 200.'959. Ferrous sulphate. Fe SO4 + 200 aq..95I. Thomsen. P. A. 142. 337. Copper sulphate. Cu SO, + 200 aq..953. Thomsen. P. A. 142. 337. Zinc sulphate. Zn SO4 + 200 aq..947. Thomsen. P. A. 142. 337. Magnesium sulphate. Mg S04 + 20 aq..744 —745. 50 "(.855-*859. } z Thomsen. P.A. 142.337. (c ((100 (C.9I7. (( 200 ((.952. Sodium nitrate. 10 per cent. solution..9320. 20,,,,.8768. 30 (( t-.834I. - Schiiller. 37. 40,, ((.7998. 50.,,, ~7673 100 parts water to 42.49 of salt..7838.. M. (3). 3 21.245 ((.8585. Atabout9 ndrews. M. (3). 36. (~ 10.622 " 1~9 I514.,( (,, 10.622 (,.9131. 9 Na NO3 + 10 aq..769.,, 25,.863. 50 ((.918. k 3 Thomsen. P.A. 142. 337. ((100 ((.950. ((200((' 975. 9 Pt. 2.-4. 50 SPECIFIC HEAT TABLES. Solution. Specific Heat. Authority, 3.03 per cent. solution..9707. r 3.73 ( (.9658. 4.81 ( 1.9523. 5.62 C (c.9442. 8.40 ( ((.9234. 11.36 (c ((.9025. 16.64 (C ((.8700. Winkelmann. P.A. 149. 19.19 (( (.8559'. 1. 25.03 (c (c.8417. 31.29. ((.8153. 40.06 (c ((.7820. 49.98 (.7576. 57.97 C.7376. 70.09 "( C.7121. Potassium nitrate. 10 per cent. solution..9I82. ) ( 20.8589. Schfller.'37. 30.8090. ) K NO3 + 25 aq..832. 50 CC.90o O "~ 10( 50 CC~.9IThomsen. P.A. 142.337. (( 100 ".942. cc ((200..966. J 100 parts water to 25.29 of salt..8I35. ) ((12.645.89I5. )Atabout x89 Andrews.P.M.(3).36.514 " 6.322 (.9369. 3.05 per cent. solution..9673. 4.15..'9575. 5.62 ( C.9458. 8.40 (C cc.9206. Winkelmann. P.A.149.1 11.11.8997. 15.31 ( (.872I. 19.80,.8484. Ammonium nitrate. NH4 NO3 + 5 aq..696-.699. f 250.859 Thomsen. P.A. 142. 337. (( 50 cc ~.929. (C ((100 (5.962. } 3.04 per cent. solution..9654. 10.01.9208. 20.00.86o6I 30.00 (.864. Winkelmann.P.A.149.1. 30.00 ( (C.8774. I 40.00.7227. J Barium nitrate. Ba N206 + 200 aq..933. Thomsen. P. A. 142. 337. SPECIFIC HEAT TABLES. 51 Solution. Specific Heat. Authority. Lead nitrate. Pb N(2~ -+ 200 aq..9I9.} { Thomsen. P.A. 142. 337. o.(.( <(.920. Sodium carbonate. Na% C03 + 50 aq..896. ) F __ 100 933- Thomsen. P.A. 142. 337. ((200 ((.958. Sodium acetate. Na C2 H3 02 + 20 aq..884. r Na "2H (( 50 (( 938. 5 00.93865. Thomsen. P.A. 142. 337. ((100 (.965. ((200 ((.983. J, Cane sugar. C12 H22 O1 + 25 aq..7558. "( 50 ((.8425. ((100 (( I.909 I. IMarignac. 42. ((200 (( 9500. ((400 (( 9742Tartaric acid. C4 H6 06 + 10 aq..745. (( 20 ((.856.:" (( 50,.9II. Thomsen. P. A. 142. 337. a ((100 (. 952. ((200 ( 975 XXII. SOLUTIONS IN CARBON DISULPHIDE. Solution. Specific Heat. Authority. Bromine. Br + C S2..I74. Marignac. 42. Iodine. I + 10 C S2..219. 4 20.228. _Marignac. 42. Sulphur. S + C S2..229. 1 (( (( 2CS..232. 42 4 ((.232. M "( ((10 ((.235. 52 SPECIFIC HEAT TABLES. Solution. Specific Heat. Authority. Phosphorus. P + 4C S2..2I9. ).c. 1.( 1.225. Marignac. 42. ""2 (C.229. ( ( 4 (.2295. XXIII. LIQUID MIXTURES. Mixture. Specific Heat. Authority. Methyl alcohol and water. 10 per cent. of C H4 0..98582. 20 o c C.95914~ 30 C C(..92658. 40 "( ((.892Ig. 50 " "(.84645. Dupr6. P. A. 148. 236. 60 " ".8o0I77. 70,, (c (.75500. 80 (( ", C.69999. 90, (( (C.64282. Ethyl alcohol and water. 1 volume alcohol + 9 vol. aq..9897. 2 * (( 8.'9835. 3 C (c (( 7 cc cc.9732. 4 CC (C (( 6 (( CC.9482. 5,,,, (, 5 ( (.9230. Schnidaritsch. WienAk. 6 c..( (( 4 (( (.8456. 38. 39. 7 (( (( (( 3,( (.8I98. 8 cc (( ((2, ".7784. i 9 (C (C (C 1 (C CC.7178. 8.4 per cent. of C2 H6 0..060.o 17 c" ((, I,.065. 25 1c (( ((.055. 34 ( (( |o30 |.o *' Jamin & Amaury. C. R. 34 (( (C,, 1.030. 50 (( ( (.940. 70. 1237. 67 (( ((,.840. 84 (C (C (C.720. SPECIFIC HEAT TABLES. 53 Mixture. Specific Heat. Authority. 5 per cent. of alcohol. I.OI502. ] 10 I(.03576. 20, (c 1.04362. 30 (C (.02602. 36 -(. 99900. 40 C.96805. 45 u ((.94192. ) I Dupre and Page. 38. 50 (( ((.90633. 60 (( 84332. 70 (( (( 78445. 80 (.71 I690. 90.,,.65764.J 14.90 cc ( I.0391. 20.00 ( I.0456. 22.56 ( CC 1.0436. 28.56 ( (( I.0354. 35.32 1c C I.0076. 44.45.9610. 49.46 (( C(.9162. 250. Schiller. See 39. 49.93 (( ((.9096. 54.09 ( (.8826. 54.45 (( ((.8793. 58.17 (( ((.8590. 73.90 (C(.777 I L 83.00, (C.7168. 10 per cent. of alcohol. I.0268. 20 I" (.0401. 30.o(( (( I.O06. 40 a ((.9726. 50,,, C.9o6I. 00 ~ Winkelmann. 44. 60..8446. 70 (( ((.78I3. 80 7I (( i.7116. 90 " ((.6448. Alcohol and benzol. 20.43 per cent. of alcohol..5022. 24.45 (( (.5112. 32.54 ( ((.5268. 48.74 (. 5465. Schiiller. See 39. 57.85 (( ((.5565. 66.89 (.5668. 80.15,,.5862. J 54 SPECIFIC HEAT TABLES. Mixture. Specific Heat. Authority. 10 per cent. of alcohol..5502. 21 (( (( 5572. 30 ( ((.5594. 40 (( 5o.5630. Winkelmann. 44. 60 " ( ~5654. 70 (.5643. 80 (( ".5660. 90 ((.5700. I Alcohol and carbon disulphide. 16.04 per cent. of alcohol..337I. 20.06 (.3560. 30.06 ( (.3989. 35.00 (( ( (.4133. 0 40.53 c(.4237. 25 Schiler. See 39, 48.64 (( ( ((.447 I 59.30 (( (( ((.4808. 70.90 ( ( ( 538. J 20 ( ( ".3474. 30 (K (( ((.3662. 40 (( (C (.4058. 50 ", C.4340.. 50 (( ((.( 4558. Winkelmann. 44. 70 "( (( (.4833. 80 ((C.5 I64. 90 (( (( ((.5460. Alcohol and chloroform. 16.75 per cent. of alcohol..3348. 28.77 (( (( (( 399933.92 ( (C CC.4I30., 39.78 ( (.4315. Schiller. See 39. 47.00 (( ( ( 4539 chller. 56.46 ((.4841. 72.80 ( ( (C.533I. J Benzol and carbon disulphide. 10 per cent. of benzol..2858. 20 C (,.3098. 30 ( ( (.3347. 50 (( (( 387I o Winkelmann. 44. 60 C " C.4146. 70,.4424. 80 (( (( ((.4702. 90,( " "'4973. ALPHABETICAL INDEX TO SUBSTANCES. PAGE. PAGE. PAGE. Aluminum and potassium Barium. Hyposulphite. 32 Acetic acid... 43 sulphate. " Nitrate. Solution 50 Acetone. 43 See potash alum. 34 " Sulphate. 33 Acid. Acetic... 43 Amalgams. See Alloys 39 Barytes. See Barite. 33 " Arselnious. Ammonia. Beeswax. 44 See Arsenic triox- See Ammonium hydrate 48 Benzol.... 40 I ide... 26, 27 Ammonium. Bromide. Solu- " with alcohol 53, 54 B B oric. tion.. 47 " " carbon disulSee Boron trioxide 26 " Chloride. 21 phide.. 54 " Butyric.. 43 " " Solution 47 Bismuth.. 17 " Formic... 43 " Hydrate. 48 " Sulphide. 29 f Hydrochloric. " Iodide. Solu- " Trioxide ~. 27 tion.. 47 Bitter spar.. 38 ride... 5 " Nitrate 35 Blende. 28 d3" "Solution 50 Blue vitriol. "!odic. 30 (" Molybdic. Sulphate. 32 See Copper sulphate 33 i See Molybdenum tri- " Solution 49 Borax. t oxide... 26 Amyl. Alcohol... 42 See Sodium diborate 35 Nitric... 31, 48 " Oxide.. 43 Boric acid. " Nitric. 31, 48 Racemic.. 44 Anglesite. 33 See Boron trioxide. 26 " (Silicic. Anhydrite... 33 Boron... 16 See Silicon dioxide 27 Ankerite. 38 " Trioxide 26 Succinic.. Anthracite... 18 Bromine. 10 Sulphuric. 30, 31, 48 Antimony.. 16, 17 " with carbon disul" Sulphuric 30, 31, 48 Tartaric... 44 " Oxides.. 27 phide.. 51 Solution 51 " Sulphide. 29 Brookite. 27 ( Titanic. Apatite... 36 Brucite.. 31 See Titanium diox- Argentic compounds. Butyric acid 43 I ide.... 27 See Silver. " Tungstic. Arragonite. 37 See Tungsten triox- Arsenic.. 26 " Chloride.. 22 C. ide.. 26 Valeric.., 43 " O 26,27 Cadmium. 15 Actinolite.... 38 " Sulphides. 29 Calcite 37 Adularia. 38 Arsenopyrite. Calcium. 11 Agate. 27 See Mispickel 30 Carbonate. 37 Albite.... 38 " Chloride.. 21 Alcohol. " " Solution 47 See Ethyl alcohol 41, 22 " Fluoride. 21 Alloys.... 39 B. " Hydrate.. 31 Allyl sulphocyanide. 45 " Malate... 44 Alums... 34 Barite..... 33 " Metaphosphate 36 Alumina. Barium. Carbonate. 37 " Oxide... 24 See Aluminum oxide 26 " Chlorate. 32 " Sulphate.. 32, 33 Aluminum... 20 " Chloride. 22 " Tungstate.. 34 " Hydrate. 31 i" " Solution 47 Camphilene... 40 Oxide. 26 " Formate. 44 Cane sugar... 44 55 56 ALPHABETICAL INDEX. PAGE. PAGE. Cane sugar. Solution. 51 Dioptase 38 PAGE. Carbon ~. 17,18,19 Dolomite... 38 Ice..24 " Chlorides.. 22 Indium.. 15 " Disulphide. 29 Iodic acid... 30 "with alcohol 54 Iodine.. 10,," " benzol 54 E. with carbon disul-,," " bromine 51 Epsom salts. phide. 51 i" iodine 51 See Magnesium sulphate 34 Iridium... 14 " phos- Ether. See Ethyl oxide 42,43 Iron... 12 phorus 52 Ethyl. Acetate.. 43 "Carbonate. 37 di tsulphur 51 Alcohol. 41,42 " Iydrate. 31 Cassiterite. See Tinstone. 27, " withwater 52,53 "Oxides... 25 Cast iron....12, 13, " benzol 53, 54 "Sulphate... 33 Caustic potash. " " chloroform 54 " " Solution. 49 See Potass. hydrate. 30,47, " "carbon di- " Sulphides... 28 Caustic Soda. sulphide 54 Iron pyrites... 28 See Sodium hydrate 47 Bromide. 45 Iserine.... 27 Celestine.. 33 " Formate. 43 Cerium... 20 " Iodide...45 Oxide. 26 " Oxalate.. 4 Cerussite. 37 " Oxide 42, 43 Cetyl alcohol 42 Oxid 42243 Cetylalcohtol... 42 Sulphydrate. Juniper. Oil of.. 40 Chalcopyrite. 30 See Mercaptan 44 Chalk.. 37 Charcoal. 18 Chloroform with alcohol 54 L. Chrome alum... 34 F1. Labradoritc..38 Chrome iron ore 27 Labado Chromite Felspar.38 Lead 11,12 Chromium. Chloride. 22 Ferrous or Ferric compounds. " Arsenate.. 36 Oxide. 25 See Iron compounds. " Borates... 35 Chromium and potassium Formic acid... 43" Bromide... 23 sulphate. See Chrome Fusel oil. " Carbonate.. 37 alum.... 34 See Amyl alcohol 42 " Chloride...22 Chrysolite.. 38 " Chromate.. 34 Cinnabar. 28 " Hyposulphite. 32 Citron. Oil of.. 40 " Iodide... 23 Cobalt 1... 13 " Molybdate.. 34 Sulphate.. 33 Gadolinite... 35 " Nitrate... 36 Sulphide.. 28 Galena.... 28 " "it Solution.. 51 Cobaltite... 30 Gas carbon.. 19 " Oxides. 24, 25 Coke... 18,19 Glass.3 8 " Phosphates.. 36 Copper... 13 Glucinum. Oxide. 26 " Sulphate.. 33 Chloride.. 22 Gold.17 " Sulphide.. 28 " Iodide... 23 Graphite... 18 Lime. See Calcium oxide 24 " Oxides... 25 Green vitriol. Litharge. " Sulphate. 33, 34 See Ferrous sulphate. 33 See Lead oxide. 24, 25 " " Solution 49 Gurhofian... 38 Lithium... 10 " Sulphide.. 28 Gypsum..3 " Chloride. 21 Copper pyrites. See Chalcopyrite.. 30 Corundum... 26 Cream... 44 I,. Cryolite.21.. 21 Curite.. 281 Heavy spar. See Barite. 33 Magnesia. ~Cupri28Hematite.... 25 See Magnesium oxide 26 Hornblende... 38 Magnesium...15 D~, RHydrogen. Chloride. 45 " Chloride. 22 Diamond... 17, 18 " Oxide. " Hydrate.. 31 Diopside... 38 See Water... 24 " Oxide.. 26 ALPHABETICAL INDEX. 57 PAGE. PAGE. PAGE. Magnesium Sulphate 33, 34 Oil. Mustard. Potassium. Tartrate.. 44 " Solu- t See Allyl sulphoc- Potassium and aluminum tion.... 49 yanide.. 45 sulphate. Magnesium and Potassium " Olive. 44 See Potash alum. 34 Sulphate... 34 " Orange... 46 Potassium and chromium Magnetite.... 25' Sperm.. 44 sulphate. Manganese.... 12 " Turpentine.. 41 See Chrome alum. 34 " Chloride. 22 Olive oil. 44 Potassium and Magnesium " Hydrate.. 31 Orange. Oil of.. 40 sulphate. 34 Oxides. 25 Orpiment... 29 " " Nickel sul" Sulphate.. 33 Orthoclase... 38 phate. 34 Manganite... 31 Osmium.... 15 " Platinum Mannite... 44 chloride 23 Marble.... 37 " " Sodium niMarcasite. 28 trate 35 Mercaptan... 44 P. "' tarMercury 15, 16 trate 44 Chlorides. 22 Pladium... See Seig" Cyanide.. 40 Paraffine.... 41 salt. Petrolene... 41 odides.. 23 " tin chloride 23 Phosphorus 1zic.. 16 MinmOxide.... 256 See" In carbon. disul" Sulphide. 28, 29 phide. " cyanide 40 " rixie. 52 Methyl. Alcohol. 41 ide sulphate 4 with water 52 Trichloride 22 Pyrite 28 Pitchblende 26 Pyrite.. Acetate. 43 Platinum.. 14 Pyrolusite... 25 " Butyrate. 43 Pyrope 38 Butyarate 43 Platinum and potassium Pyr.... Valerate.. 43.. 3 Pyrrhoite... 28 chloride... 23 Molybdenite. 28 Potassium. Arsenates 36 Molybdenum k15 Borates.. 44. " Suulph hide.. 28 IBromide. 23 Quartz Ch d. 26 Trioxide 26 " Solumbic compounds. M oly bdenite.. 28 S Potassium. Arsenates. 36 Nolybdenum.... 4 " rates. 44 5 See Allyl suphocyan- Chlorate. 32 f " Sulphromide ates. 2 Naphtha. 41 Ferrocyanide 40. 23 uartz.. 26 "c Trioxide. 261'1 ilC"kel. 13 " Solu uiRochelle salt. Juxnidper. 23 40ulhtion 47 See Calcium oxSeignette salt. 24 Sulphe " y Rubidium. Carbonate. 3737 Iodide 23 Chloride. 2121 ~Nitre. " Solu- R, tSee Potassium nitrate 35 ion. 5046 NitrobenzolRacemic acid. Oxalates. 44 PeChromate. 34 Fermanricyganaide 34 Sal ammoniac. Su ephates d s32 l ide... 29 Oil. Citron.. 13 40 " Solu- Salt. # ~Juniper. ~40 tion 49 See Sodium chloride. 21 " Juniper.. 40 tion 49 See Sodium chloride 21 53 ALPHABETICAL INDEX. PAGE. PAGE. USaltpetre. Specular iron ore 25 PAGE. See Potassium nitrate 35 Sperm oil. 44 Uranium.. 13 Samarskite... 36 Spinel.. 27 " Oxides.. 26 Sapphire... 26 Stannic and stannous. Scheelite. See Tin. See Calcium tungstate 34 Steel.13 Seignette salt...44 Stibnite.. 29 V. Selenium.. 11 Strontium. Carbonate 37Valerie acid 43 " Sulphide. 28 " Chloride. 22 Vanadium. Trioxide 26 Silica. " Nitrate. 35 See Silicon dioxide. 27 " Sulphate. 33 Silicon.. 19 Succinic acid... 44 " Chloride.. 22 Sugar..4 4.. " Dioxide 27 " Solution.. 51 Silver o... 11 Sulphur. 11 Water.24 "Bromide.. 23 " in carbon disulph- Witherite 37 "Chloride. 21 ide. 51 lfram. 5134:' Iodide. 23 " Chloride. 21 Wolframium. " Nitrate.. 35 Sulphuric acid 30, 31, 48 See Tungsten 15 " Phosphate.. 36 Wollastonite... 38 " Sulphide... 28 Wood spirit. Smaltite.30. See Methyl alcohol 41 Snow.. 24 T. Wulfenite. Sodium.... 10 Tabular spar. " Acetate. Solution 51 See Wollastonite. 38 " Borates.. 35 Tartaric acid. 44 " romide... 23 " Solution. 51 Y, " Carbonate. 37 Tellurium. 11 " Solution 51 Terebene. 40 Yttrium oxide, or Yttria. 26 " Chloride. 21 Terebilene. 40. Solution 45, 46 Thallium. 11' Fluoride.. 21 Tin... 19, 20 z Hydrate. Solution 47 Chlorides. 23 Hyposulphite 32 " Oxides. 27 Zinc.15 " Iodide... 23 " Sulphides. 30 " Carbonate. 38 Solution. 47 Tin and potassium chloride 23 " Chloride. 22 Nitrate.. 35 Tinstone. 27 " Oxide.. 26. Solution 49, 50 Titanic acid. " Sulphate. 33, 34 " Phosphates. 36 See Titanium dioxide 27 I" " Solution. 49 " Sulphate. 32 Titanium. Chloride.. 23 " Sulphide.28 Solution. 48 " Nitride.. 30 Zinc and potassium chlorSodium and hydrogen sul- " Oxide. 27 ide. 23 phate. Solution.. 49 Topaz 38. 3" " cyanide 40 Sodium and potassium ni- Tremolite... 38 " " sulphate 34 trate 35 Tungsten... 15 Zinc blende 28 (...... tar- " Trioxide 1 Zircon.. 38 trate. Tungstic acid Zirconium... 20 ( See Seignette salt.. 44 Turpentine.. 41 Zoisite 38 SMITHSONIAN MISCELLANEOUS COLLECTIONS. 289 THE CONSTANTS OF NATURE. PART III. TABLES OF EXPANSION BY HEAT FOR SOLIDS AND LIQUIDS. COMPILED BY FRANK WIGGLESWORTH CLARKE, S. B. PROFESSOR OF CHEMISTRY AND PHYSICS IN THE UNIVERSITY OF CINCINNATI. WASHINGTON, D. C.: PUBLISHED BY THE SMITHSONIAN INSTITUTION. APRIL: 1876. ADVERTISEMENT. THE following is the third part of a general work on the " CONSTANTS OF NATURE," prepared gratuitously for the Smithsonian Institution by Professor F. W. Clarke, and published at the expense of its fund. JOSEPH HENRY, Secretary Smithsonian Institution. WASHINGTON, APRIL, 1876. PHILADELPIIIA: COLLINS, PRINTER. TABLE OF CONTENTS. PAGE. I.-INTRODUCTION........... 4 2.-LIST OF IMPORTANT PAPERS. 5 3.-EXPLANATORY NOTES. 9 4.-TABLES OF LINEAR EXPANSION. 11 I.-ELEMENTARY SUBSTANCES. 11 II.-FLUORIDES, AND IODIDES. 16 III.-OXIDES, AND SULPHIDES........ 17 IV.-SULPHATES, CARBONATES, AND PHOSPHATES. 18 V.-SILICATES. 18 VI.-ALLOYS......... 20 VII. —MISCELLANEOUS.......... 21 5.-TABLE OF CUBICAL EXPANSIONS. 22 I.-ELEMENTARY SUBSTANCES. 22 II.-FLUORIDES, CHLORIDES, BROMIDES, AND IODIDES..... 25 II. —OXIDES........ 27 IV.-SULPHIDES............. 30 V.-HYDRATES......... 31 VI.-SULPHATES, HYPOSULPHITES, AND CHROMATES...... 31 VII. —CHLORATES, NITRATES, AND PHOSPHATES...... 33 VIII.-CARBONATES.........33 IX.-SILICATES.. 34 X.-MISCELLANEOUS INORGANIC BODIES. 350 XI.-ALLOYS......... 36 XII.-HYDROCARBONS...................... 37 XIII.-COMPOUNDS CONSISTING OF C, H, AND 0...... 39 XIV.-COMPOUNDS CONSISTING OF C, H, N, OR C, H, N, O.... 47 XV.-CHLORINATED ORGANIC COMPOUNDS. 48 XVI.-BROMIINATED ORGANIC COMPOUNDS.. 50 XVII.-ORGANIC IODINE COMPOUNDS. 51 XVIII. —ORGANIC COMPOUNDS CONTAINING SULPHUR. 52 XIX. —METALLIC SALTS OF ORGANIC ACIDS....... 52 XX.-MISCELLANEOUS ORGANIC COMPOUNDS. 53 3 INTROD UCTION. IN the following tables will be found data for the expansion by heat of about three hundred and fifty different substances. In every case the coefficient for one degree is given, a rule which involved many tedious reductions during the process of compilation. It will be noticed that the linear and cubical co6fficients are collected separately. This has been so arranged in order to avoid confusion. It would have been easy for the compiler to have given in many cases either the cubical co6fficient or the linear coefficient by itself, leaving it to the reader to multiply or to divide by three in order to obtain the other value. But this would have manifestly involved great inaccuracies, since the cubical coefficient is not in every case exactly treble the linear. Accordingly the compiler has in no instance given a cubical value deduced by himself from a linear, or vice versa. Every determination given must rest solely upon the original authority of the experimenter. For errors involved in reducing to the single centigrade degree the compiler is alone responsible. One difficulty was encountered in dealing with the expansion rates of liquids; namely, that the data given were often too full for incorporation in tables such as these. For instance: in most of Kopp's determinations, the volume of each liquid is given at many temperatures, say at every five degrees from 0~ up to 1000 and over. In some cases, even, determinations are given for every degree. In such instances the compiler has simply selected from the list the values at two, three, or four salient temperatures, and has referred to the original paper for the rest. For these tables absolute completeness cannot be claimed. Nothing will be found in them relating to the expansion of liquid mixtures or of solutions. In all other directions, however, it is hoped that they will prove practically complete, at least up to January 1st, 1876. F. W. C. A LIST OF SOME IMPORTANT PAPERS UPON EXPANSION. 1. DULONG AND PETIT. —"Recherches sur la mesure des temp6ratures, et sur les lois de la communication de la chaleur." Ann. Chim. Phys. (2). 7. 113. 1818. 2. HXiLLSTR6M. " Untersuchungen fiber die Volumensverinderungen, welche das Wasser durch die Wiirme erleidet, und Bestimmung der Temperatur bei welche dasselbe seiner grdsste Dichtigkeit besitzt." Pogg. Ann. 1. 1824. p. 129. See also another paper in v. 9. 1827. p. 530. 3. MITSCHERLICH. " Ueber das Verhaltniss der Form der krystallisirten Kbrper zur Ausdehnung durch die Wirme." Pogg. Ann. 1. 125. 1824. 4. ERnrAN. "Ueber den Einfluss der Liquefaction auf das Volunien und die Ausdehnbarkeit einiger Korper." Pogg. Ann. 9. 557. 1827. 5. MITSCHERLICH. " Ueber die Ausdehnung der krystallisirten Korper durch die Wairme." Pogg. Ann. 10. 137. 1827. 6. DANIELL. " On a new register-pyrometer, for measuring the expansion of solids, and determining the higher degrees of temperature upon the common thermometric scale." Phil. Trans. 1830. 237. 7. DANIELL. "Further experiments with a new register-pyrometer for measuring the expansion of solids." Phil. Trans. 1831. 443. 8. MUNCKE. "Ueber die Ausdehnung der tropfbaren Fluissigkeiten durch WiVirine." Mem. Acad. St. Petersburg. Savans Etrang. I. 249. 1831. 9. STAMIPFER. "Versuche zur Bestimmung des absoluten Gewichts des Wassers, der Temperatur seiner grossten Dichtigkeit, und der Ausdehnung derselben." Pogg. Ann. 21. 75. 1831. 10. MUNCKE. "Sur la dilatation de l'alcohol absolu et du carbure de soufre par la chaleur." Ann. Chim. Phys. (2). 64. 5. 1837. 11. DESPRETZ. "Untersuchungen fiber das Maximum der Dichtigkeit bei Fliissigkeiten." Pogg. Ann. 41. 58. 1837. Compt. Rend. 1837. 12. MITSCHERLICH. " Ueber die Bestimmung der Ausdehnung krystallisirten K6rper durch die Wiirme." Pogg. Ann. 41. 213. 1837. 5 6 A LIST OF SOME IMPORTANT PAPERS UPON EXPANSION. 13. DESPRETZ. "Observations sur la dilatation du soufre." Compt. Rend. 7. 589. 1839. 14. DESPRETZ. "Recherches sur le maximum de densit6 de l'eau pure, et des dissolutions aqueuses." Ann. Chim. Phys. (2). 70. 5. 1839. 15. Kopp. "Recherches sur le volume specifique." Ann. Chim. Phys. (3). 4. 462. 1842. 16. REGNAULT. "Note sur la dilation du verre." Ann. Chim. Phys. (3). 4. 64. 1842. Pogg. Ann. 55. 584. 17. KoPP. "Ueber den Zusammenhang zwischen der chemischen Constitution und einiger physikalischen Eigenschaften bei fiissigen Verbindungen." Ann. Chem. Pharm. 50. 71. 1844. 18. SALM-HORSTMAR. "Ueber die Ausdehnung des fliissigen Wassers unter dem Gefrierpunkt." Pogg. Ann. 62. 283. 1844. 19. BRUNNER. "Experiences sur la densite de la glace a diff6rentes temp6ratures." Ann. Chim. Phys. (3). 14. 369. 1845. 20. PIERRE. "Recherches sur la dilatation des liquides." Ann. Chim. Phys. (3). 15. 325. f845. 21. Continuation of 20. Ann. Chim. Phys. (3). 19. 193. 1847. 22. PLAYFAIR AND JOULE. "On atomic volume and specific gravity." Chem. Soc. Memoirs. 2. 401 1845. Second paper, vol. 3. 57. 1848. 23. KoPP. "Untersuchungen iiber das specifische Gewicht, die Ausdehnung durch die Wirme, und den Siedpunkt einiger Flfissigkeiten." Pogg. Ann. 72. 1847. Two papers, pages 1. 223. 24. PIERRE. "Recherches sur les proprietes physiques des liquides, et en particulier sur leur dilatation." Ann. Chim. Phys. (3). 20. 5. 1847. 25. PIERRE. " Recherches sur la dilatation et sur quelques autres propri6tes physiques de l'acide sulfureux anhydre et du sulfite d'oxyde d'ethyle." Ann. Chim. Phys. (3). 21. 336. 1847. 26. PIERRE. " Memoire sur la thermometrie, et en particulier sur la comparaison du thermometre a air avec les thermomeitres a liquides." Compt. Rend. 27. 213. 1848. Pogg. Ann. 76. 458. 27. PLAYFAIR AND JOULE. "Researches upon atomic volume and specific gravity." Journ. Chem. Soc. 1. 1849. Two papers, pages 121, 139. 28. MILITZER. "Ueber die Ausdehnung des Quecksilbers durch die Warme." Pogg. Ann. 80. 55. 1850. 29. PIERRE. "Recherches sur les propriet6s physiques des liquides, et en particulier sur leur dilatation." Ann. Chim. Phys. (3). 31. 118. 1851. 30. PIERRE. "Recherches sur la dilatation." Ann. Chim. Phys. (3) 33. 199. 1851. 31. KoPP. "Ueber die Ausdehnung einiger fester Korper durch die Wirme." Ann. Chem. Pharm 81. 1. 1852. Pogg. Ann. 86.156. A LIST OF SOME IMPORTANT PAPERS UPON EXPANSION. 7 32. FRANKENHE1M "Ueber das Volumen des Wassers bei verschiedenen Temperaturen, nach Is. Pierre's Beobachtungen." Pogg. Ann. 86. 451. 1852. 33. HAGEN. "Ueber die Ausdehnung des destillirten Wassers unter verschiedenen Wirmegraden." Abhandl. Akad. d. Wiss. Berlin. 1855. 34. KoPP. "Beitrage zur Stochiometrie der physikalischen Eigenschaften chemischer Verbindungen." Ann. Chem. Pharm. 96. 1855. Three papers, pages 1. 153. 303. 35. KoPP. "Untersuchungen fiber das specifische Gewicht, die Ausdehnung durch die Warme, und den Siedpunkt einiger Flussigkeiten." Ann. Chem. Pharm. 94, 257. 95, 307. 98, 367. 1855-6. 36. KoPP. " Ueber die specifische Volume der Stickstoffhaltigen Verbindungen." Ann. Chem. Pharm. 100. 19. 1856. 37. PFAFF. "Untersuchungen fiber die Ausdehnung der Krystalle durch die WMrme." Pogg. Ann. 104. 171. 1858. Second paper, v. 107. 148. 38. DRION. " Note sur la dilatabilite des liquides chauffes A des temperatures superieures a celle de leur ebullition." Compt. Rend. 46. 1235. Pogg. Ann. 105. 158. 1858. 39. D'ANDREEFF. "Recherches sur le poids specifique et la dilatation par la chaleur de quelques gaz condenses." Ann. Chim. Phys. (3). 56. 317. 1859. 40. SORBY. " On the expansion of water and saline solutions at high temperatures." Phil. Mag. (4). 18. 81. 1859. 41. HAHN. " On the expansion of crystalline bodies by heat." Phil. Mag. (4). 18. 155. 1859. 42. MENDELEJEFF. "Notiz fiber die Ausdehnung homologer Flfissigkeiten." Ann. Chem. Pharm. 114. 165. 1860. 43. MENDELEJEFF. "Ueber die Ausdehnung der Flfissigkeiten beim Erwarmen fiber ihren Siedepunkt." Ann. Chem. Pharm. 119. 1. 1861. 44. CALVERT, JOHNSON, AND LOWE. "On the expansion of metals and alloys." Chem. News. 3. 1861. Pages 315, 357, 371. 45. DUVERNOY. "Ueber die Ausdehnung des Wassers beim Gefrieren." Pogg. Ann. 117. 454. 1862. 46. FIZEAU. "Recherches sur la dilatation et la double refraction du cristal de roche echauff." Ann. Chim. Phys (4). 2. 143. 1864. 47. FIZEAU. "Sur la dilatation du diamant et du protoxyde du cuivre crystallise sous l'influence de la chaleur." Compt. Rend. 60. 1161. 1865. 48. WEIDNER. " Die Ausdehnung des Wassers bei Temperaturen unter 4~ R." Pogg. Ann. 129. 300. 1866. 49. FIZEAU. "Memoire sur la dilatation des corps solides par la chaleur." Ann. Chim. Phys. (4). 8. 335. 1866. Pt. 3.-5. 8 A LIST OF SOME IMPORTANT PAPERS UPON EXPANSION. 50. MATTHIESSEN. "On the expansion by heat of water and mercury." Phil. Trans. 1866. 231. 51. MATTHIESSEN. "On the expansion by heat of metals and alloys." Phil. Trans. 1866. 861. Pogg. Ann. 130. 50. 52. HIRN. " Memoire sur la thermodynamique. Recherches exp6rimentales sur la dilatation et sur la capacite calorifique a des hautes temperatures de quelques liquides tres-volatiles." Ann. Chim. Phys. (4). 10. 32. 1867. 53. ROSSETTI. "Sur le maximum de densite et la dilatation de l'eau distillee." Ann. Chim Phys. (4). 10. 461. 1867. Second paper, v. 17, 370. 1869. 54. LOUGUININE. "ELtude des densites et dilatations de la benzine et de ses homologues." Ann. Chim. Phys. (4). 11. 453. 1867. 55. FIZEAU. " Sur la propriet6 que possede l'iodine d'argent de se contracter par la chaleur et de se dilater par le froid." Compt. Rend. 64. 314. 1867. Another paper, same vol., p. 771. 56. FIZEAU. "Tableau des dilatations par la chaleur de divers corps simples metalliques on non metalliques, et de quelques composes hydrogenes du carbone." Compt. Rend. 68. 1125. 1869. E:XPLANATORY NOTES. IN the following tables the coefficients of expansion given are always the coSfficients for one degree Centigrade. When the coefficient is followed by one temperature, as,.00001188.400, it is the true coefficient at that temperature. When two temperatures are appended, as,.0001105, 0~-100~, the coefficient is the mean value for any one degree between them. But few abbreviations, save in the references to original papers, have been used. The letters S. or L., affixed to the name of a substance, indicate that it is either solid or liquid, as the case may be. The minus sign prefixed to a coefficient, indicates that the letter represents contrccti on, instead of expansion. The following abbreviations are employed in referring to sources of information, original papers, &c. A single number attached to the name of an authority, refers to the paper bearing that number in the list accompanying the tables. References to periodicals are followed by numbers giving (when necessary) the series, volume, and page. Am. Chem. "American Chemist." A. C. P. "Annalen der Chemie und Pharmacie." A. C. Phys. "Annales de Chimie et de Physique." Baier Akad, Phys. Abhandl. "Baierisches Akademie. Physikalische Abhandlungen." B. D. C. G. "Berichte der Deutschen Chemischen Gessellschaft." B. S. C. "Bulletin de la Societe Chemique." C. S. J. "Journal of the Chemical Society." Gilb. Ann. "Gilbert's Annalen." Gren's J. "Gren's Journal." J. "Jahresbericht fiir Chemie." J. F. P. "Journal fuir Praktische Chemie." ii 10 EXPLANATORY NOTES. P. A. "Poggendorf's Annalen." P. M. "Philosophical Magazine." P. T. "Philosophical Transactions." W. D. "Watt's Dictionary." Young's Nat. Phil. "Young's Natural Philosophy." A TABLE OF LINEAR EXPANSIONS. I. ELEMENTARY SUBSTANCES. Name. CoSff. of Expansion. Authority. Hydrogen. Fluorine. Chlorine. Bromine. See cubical table. Iodine. c c Lithium. Sodium. Potassium. Rubidium. Caesium. Silver. See also cubical table..00002120. 00~-I00. Muschenbroek. W. D. 3. 68..00002I 000. (c Ellicot. (C.0000oooo8900. (( Herberf.0000208260. (( Troughton. o Cupelled..oooo000090974. Lavoisier &Laplace. W. Paris standard..ooooI90868. (( L D ce. 68..0(( 0009oooo8870.., Guyton-Morveau. A. C.. Phys. 90. 237..0000Io9496. I6o.6Ioo. ).000020657. I6~.6-35o0. Daniell. 7. {C.000020488. 16o.6-I024o. cc.000019I00. 00-I00~. Kupffer. P. A. 86. 310..0000I99ggoo. c Calvert, Johnson & Lowe..0000I943. (C Matthiessen. 51. [44.,x Cast..0000o92I. At 40~. Fizeau. 56. Thallium..00003021. At 4o0~. cc c Oxygen. Sulphur. Sicily..000064I3. At 40~. Fizeau. 56. CC See also cubi- C, C cal table. Selenium. Cast..00003680. (c, (C Tellurium., o.ooo0o675. cc CC c Lead. See also cubical table..00002867. 0-I00oo. Smeaton. W. D. 3. 68.,(.0000284836.,, Lavoisier & Laplace. W. D. 3. 68. cc.000027I948.,, Guyton-Morveau. A. C. Phys. 90. 287. 11 12 LINEAR EXPANSION TABLES. Name. Coeff. of Expansion. Authority. Lead..0000290. er. ee 31 ((.0000295. Prinsep..00002785. I6~.6-Ioo. Daniell. 7. ((.00002968. I6~.6-322~..000030I. 0~-I00~. Calvert, Johnson & Lowe..00002799. cc Matthiessen. 51. [44. ct.00002924. At 4o0. Fizeau. 56. Calcium. Strontium. Barium. Chromium. Manganese. Iron. See cubical table..ooooI I56. o~-Ioo~. Borda. W. D. 3. 68.,(.00001258.,, Smeaton., Wire..0000ooooI4401. " Troughton., Forged..ooooI22045. ( Lavoisier & Laplace. W. ( Wire drawn..ooooI23504. ) D. 3. 68..OOOI09980. o. Guyton-Morveau. A. C. Phys. 90. 237..0000oII8203., Dulong & Petit. WV. D. 3.68..00001 79. I6o.6-Ioo. t Daniell. 7.,c oooo0I344. 16O.6-35o0..0000I I900. 0~-I00. Calvert, Johnson & Lowe. Red. by H. Com- [44. pressed..oooo I88. ) For electromagnet.OOOOI2IO. 40o~. Fizeau. 56. M, eteoric. Caille..ooooio95. Steel. Annealed..ooooI2200. 00~-I00~. Muschenbroek. WV. D. ( Tempered..000013700. (( 3. 68. H( ard..0000122500. " Smeaton. W. D. 3. 68. Blistered..0000II 5000. ((,.oocci1898..0oooII898. " } Troughton. W. D. 3. 68. <(~ ~.000011899. ((, Not tempered..oooo0o7875. 0OOOO107956. (. Tempered yellow..000OI36900. Lavoisier & Laplace. W. (.OOOOI38600. 0 ID. 3. 68. Tempered at high.ooooI23956. J [t~..0000oooo447. Roy. W. D. 3.68.,, Blistered..0000112500. 0 Phil. Trans. 1795, p. 428.,( French cast. Tempered..00001322. ) French cast. Annealed..ooooI IOI. I 40~. Fizeau. 56. English cast. Annealed..oooo0001095. LINEAR EXPANSION TABLES. 13 Name. Coeff. of Expansion. Authority. Steel. Soft..o000I03. 00~-I00. Calvert, Johnson & Lowe. Cast iron..oooo I I I I I. Lavoisier. W. D. 3. 68. [44. (( a.0000I 10940. ( Roy.. c(c c.000010707. I6~.6-Ioo00. (( C(.0000I 829. I6~.6-350~. Daniell. 7. i( (c.000010829. I6~.6-I530o. ) [44. OOOOI.0000112. 0~ —I00. Calvert, Johnson & Lowe., <( Gray..ooooio06I, 40~. Fizeau. 56. Cobalt. Red. by H. Compressed..00001236, 400. Nickel. Red. by H. Compressed..000OI279, 400. Uranium. Copper. See also cubical table..000019100. 0~-I0oo0. Muschenbroek. W. D. 3.68..000O170. Snieaton. See 31. (C.1OOOO78. Borda...oooo.0000 88. o0~-Ioo. Troughton. WV. D. 3. 68..0000ooooI72244.. Lavoisier & Laplace. W. f O I.0000171222. (( J D. 3. 68. if.000oI79o03.. Guyton-Morveau. A. C. Phys. 90. 237. o,.000017182I.,, Dulong & Petit. W. D. 3.68. (.oo00007I. (C Horner. See 31..,.OOOO I69. (, Prinsep.,,.0000 7 Ioooo46. I60.6-Ioo0. ) I.000oi9037. I6~.6-350o. Daniell. 7. o(.000022688. I6~.6-Iog9I. ).ooooI 866. o~-I oo. Matthiessen. 51. Native. L. Superior..ooooI69o.400 Fizeau. 56. Commercial..0000I678. 4 Ruthenium. Semi-fused..ooooo963. 400. Fizeau. 56. Rhodium..000008 50ooooo8. 40~. i ( Palladium. See also cubical table..ooooIooooo. 0o-Ioo~. Wollaston. W. D. 3. 68. (. I I0000 14. (( Matthiessen. 51.,, Forged..oooo0000I76. 4o0. Fizeau. 56. Platinum. See also cubical table. 000ooooo009980. o~-Ioo.' Troughton. W. D. 3. 67..0000085655. (, Borda. cc.0000088420. ( Dulong & Petit.,, gave 68.61; (2) 58.59; and (3) 68.55, or a mean of 68.583. The salt for the experiments marked (1) was prepared by recrystallization and precipitation with alcohol; that for (2) by a repetition of the same process, and for (3) by resolution of (2) and precipitation with chlorhydric acid gas. Marignac proved that the precipitated argentic chloride contained entirely insignificant traces of barium salt. Cl - 35.5. (Bibl. Univ., Archives des Sciences, Nouv. Serie., 1, 1858, 209.) J. DuMAS: 137 (O 16). Determined by fifteen experiments on the titration of barium chloride with argentic nitrate, which give a general average of 68.516 with an extreme difference of 0.11. The barium chloride was prepared from pure nitrate and pure carbonate, and from commercially pure chloride after it had been freed from lead by precipitation with barium sulphide. The chloride was precipitated from solution by chlorhydric acid gas and melted in a current of chlorine to prevent oxidation. Ag= 108; Cl = 35.5. (Annales de Chimie et de Physique, (3,) 55, 1859, 137.) BERYLLIUM. The atomic heat of beryllium has been determined by J. Emerson-Reynolds by direct comparison with that of silver. BERYLLIUM. 17 In a calorimetric apparatus constructed for the purpose, the amount of heat given off during cooling by 108 parts of silver heated to 1000 was found to be equal to that communicated by a little more than 9.2 parts of beryllium under the same conditions. Assuming the atomic weight of the metal to be 9.2, the atomic heat found would be 5.91. The smallness of this number the observer accounts for bv supposing that there was a trace of platinum present introduced by the use of platinum vessels in the course of reduction. (Phil. Mag., (5,) 3, 1877, 38.) J. J. BERZELIUS: 14.5 (O - 16). Berzelius analysed the salt formed by saturating dilute sulphuric acid with beryllium oxide. From the amount of barium sulphate obtained he inferred that the atomic weight of beryllium was 331.261 on the supposition that the oxide was Be, + 03 and that the salt was neutral. Berzelius took O = 100; S = 200.75, and Ba = 855.29. [Awdejew having discovered that this salt is basic, this value is reduced to 90.63; or, for O- =16, to 14.5.] Berzelius accepted Awdejew's determination in preference to his own. (Poggend. Annal., 8, 1826, 187; and Lehrbuch der Chemie, 5th ed., 3, 1225.) T. THOMSON: 36 (O = 16). Experiments not given. The value is four times nine, and may have arisen from a mistake as to saturation. (System of Chem. 7 ed., 1, 1831, 459.) -. AWDEJEW: 13.85 (O = 16); 86.58 (O = 100). Beryllium sulphate, in chlorhydric acid solution, was decomposed with barium chloride. In the filtrate the excess of barium chloride was precipitated with sulphuric acid, and the beryllium oxide thrown down with ammonia, dried, heated, and weighed. The beryllium sulphate was prepared from pure carbonate by treatment with sulphuric acid and precipitation with alcohol. It was purified by recrystallization. Four experiments were made, the mean of which calculated for S = 201.165, gave Be = 58.084 with an extreme difference of 1.955. (Poggend. Annal., 56, 1842, 106.) Weeren recalculated these analyses for S = 200 and got 57.72, [or 2 of 86.58.] (Poggend. Annal., 92, 1824, 124.) 2 18 ATOMIC WEIGHT DETERMINATIONS. J. WEEREN: 13.83 (O = 16); 86.46 (O = 100). Weeren followed the same method as Awdejew, except that he precipitated the beryllium with ammonium sulphide, the oxide being soluble in excess of ammonia. The mean of four experiments gave 57.64, the extreme difference being 1.52 for 0 =100, [57.64 is 2 of 86.46.] Weeren took S = 200. (Poggend. Annal., 92, 1854, 124.) G. KLATZO: 13.89 (O = 16). Klatzo made five analyses of the sulphates containing seven and four molecules of water, precipitating the sulphuric acid as barium sulphate, and the beryllium as oxide by means of ammonia. From a comparison of the sum of the oxide found in all the analyses with the total amount of barium sulphate found, IKlatzo deduces Be = 9.227, for Ba = 137, and S = 32. [If Ba is taken equal to 137.16, and S - 32.07, and if each of the analyses is calculated for itself, Be = 13.89. The extreme difference is 0.45.] The sulphates were purified by recrystallization, and treatment with alcohol. (Erdmann's Journ. fiir Prak. Chemie, 106, 1868, 227; Klatzo, Ueber die Constitution der Beryllerde, Dorpat, 1868.) L. F. Nilson and- O. Pettersson have redetermined the specific heat of beryllium within a few weeks. They find the specific heat 0.4079, corresponding to a trivalent metal and a sesqui-oxide. The investigation seems to have been made with great care, while that of Emerson-Reynolds was merely preliminary. (Berlin, Bericht der chem. Ges., 11, 1878, 386.) BISMUTH. Dulong and Petit, Regnault, and KIopp, have determined the specific heat of Bismuth. It corresponds to an atomic weight of about 210. (Gmelin-Kraut, 1. c.) P. LAGEREJELM: 212.86 (O -= 16); 1330.377 (O - 100). Metallic Bismuth was oxidized in a weighed vessel by nitric acid, and the nitric acid expelled by heat. 10 grammes of bismuth gave 11.1275 oxide. (Berzelius' Lehrbuch der Chemie, 5th ed., 3, 1216; Stockholm, Akad. Handl., 34, 1813, 219.) BORON. 19 R. SCHNEIDER: 208 ( — = 16); 1299.98 (O = 100). Determined by eight experiments on the conversion of metallic bismuth into oxide by solution in nitric acid and decomposition of the nitrate in the same vessel. The escaping gases were led through nitric acid, and the bismuth caught in this way was separately converted into oxide and weighed. In four experiments the bismuth was prepared by the reduction of basic nitrate, and for the other four by the reduction in hydrogen of the oxide formed in those which preceded. 100 bismuth oxide were found to contain a mean of 89.655 metal; extreme difference, 0.048. (Poggend. Annal., 82, 1851, 303.) J. DUMAS: 210.44 (O = 16). Determined by seven experiments on bismuth chloride, which was decomposed in solution by sodium carbonate, and the sodium chloride thus formed titrated with silver solution. The value taken is the mean result. The extreme difference is 1.12. Dumas takes Ag = 108, and C1 = 35.5. The bismuth chloride was prepared by the action of chlorine on bismuth, and was purified by fractional distillation over bismuth. That employed in the experiments was colorless. (Annal. de Chimie et de Physique, (3,) 55, 1859, 176.) BORON. The specific gravities of a number of volatile compounds of boron have been determined by Dumas, Woehler and Deville, and others, and correspond to an atomic weight of about 11. (Gmelin-Kraut, 1. c.; L. Meyer, 1. c.) H. F. Weber has discovered that the specific heat of boron rises rapidly with the temperature, becoming nearly constant at 600~. Above this temperature its specific heat is 0.5, and its atomic heat 5.5. (Poggend. Annal., 154, 1875, 575.) J. J. BERZELIUS: 11.01 (O = 16). Davy's investigations having shown that boracic acid contains about 68 per cent. oxygen, and having thus established the formula of borax, Berzelius determined the atomic weight from the water contents of that salt. He found in three experiments, without variation, 47.1 per cent. Gmelin-Kraut recalculates this composition with Stas' atomic 20 ATOMIC WEIGHT DETERMINATIONS. weights, and gets the value given. (Poggend. Annal., 8, 1826, 19.) A. LAURENT: 10.86 (O = 16). Laurent found that borax retains some water even when melted, which, however, can be expelled by the addition of iceland spar. By repeating Berzelius' experiments, and adding a known weight of spar, he found the water contents in two experiments 47.15 and 47.20. HIe did not regard the experiments as accurate. Gmelin-Kraut recalculates these data with Stas' atomic weights, and gets B10.91 and 10.81. (Paris Comptes Rendus, 29, 1849, 5.) WOEHLER and DEVILLE: 10.87 (O- 16). These chemists titrated the bromide and the chloride of boron with argentic nitrate. They do not offer the analyses as atomic weight determinations, but Dumas applies the data to this object. Taking Ag = 108, and Cl = 35.5, Dumas calculates from the analysis of the chloride prepared by the action of -I C1 on B, B = 11; from the analysis of the chloride prepared by the action of Cl on B, B = 10.6; from the analysis of the bromide prepared by the action of bromine on boron, B = 11. (Annal. de Chimie et de Physique, (3,) 52, 1858, 88; 55, 1859, 129.) T. THOMSON: 10.67 (O = 16). Thomson supposed boracic acid to be composed of one atom of boron and two of oxygen, and concluded from Davy's and his own experiments that the atom of B was exactly equal to that of O. For the correct composition of the acid his value must be reduced one-third. (System of Chem., 7th ed., 1, 1831, 214.) BROMINE. Mitscherlich determined the vapor density of bromine, and Regnault the specific heat in a solid condition at very low temperatures. Both of these constants correspond to an atomic weight of 80. (Gmelin-Kraut, 1. c.; L. Meyer, 1. c.) A. J. BALARD: 75 (O = 16); 468.85 (O = 100). 1.27 potassium bromide decomposed with sulphuric acid BROMINE. 21 gave a residue of 0.973 potassic sulphate. [If this analysis is calculated with Stas' atomic weights, it gives Br = 74.65.] In another experiment 100 parts of argentic bromide reduced with zinc, the excess of which was extracted with sulphuric acid, gave 58.9 parts silver. [Calculated with Stas' data this gives Br = 75.3.] Balard mentions no special precautions in the preparation of his salts for this determination. (Annal. de Chimie et de Physique, 32, 1826, 357, 362.) J. LIEBIG: 75.29 (O = 16); 470.55 (O = 100). 2.521 potassic bromide precipitated with argentic nitrate gave 4.041 argentic bromide. The potassic bromide was obtained by adding potassic hydrate to an alcoholic solution of bromine until the solution began to lose color. (Annal. de Chimie et de Physique, 33, 1826, 331.) J. J. BERZELIUS: 78.264 (O = 16); 489.15 (O = 100). Berzelius suspected that insufficient precautions had been taken in the preceding determinations to get rid of chlorine. He washed bromine for a long time, and converted it into zinc bromide and ammonium bromide. These salts he partially precipitated with argentic nitrate to get rid of chlorine. From the filtrate he precipitated argentic bromide which he washed, dried, and melted. 7.202 of this bromide, decomposed in a current of chlorine, yielded 5.546 argentic chloride; 7.8805 bromide gave 6.069 chloride. If Ag = 1351.607, and Cl - 442.652, the mean value of Br is as above; differ-,ence, 0.09. (Pogqend. Annal., 14, 1828, 565; Kongl. vet. Akad. Hlandl., 1828.) C. LOEWIG: 75.76 (O = 16). According to Gmelin-Kraut, Handbuch der Chemie, the determination was published in a treatise entitled Brom und Seine Chemische Verhdltnisse, Heidelberg, 1829. C. MARIGNAC: 79.957 (O = 16). In three experiments a known weight of silver was dissolved in nitric acid, precipitated with potassium bromide, and the argentum bromide dried at 200~ and weighed. [For Ag = 107.93 these experiments give Br = 79.938, with an extreme difference of 0.018.] In vacuo this result is, according to Stas, 79.968. In seven experiments a known weight of silver was precipitated by a determinate amount of potassic bromide by titration. [If K = 39.137, and Ag = 107.93, 22 ATOMIC WEIGHT DETERMINATIONS. this gives bromine = 79.924 with an extreme difference of 0.046.] In vacuo this becomes, according to Stas, 79.945, In four experiments potassium bromate was decomposed by heat, and the potassic bromide weighed. [For K-I=39.137 these experiments give bromine at 80.11 with an extreme difference of 0.56. These latter are evidently much less accurate than the preceding, and I have therefore averaged the first and second series in vacuo.] The. KBr was prepared by heating bromate purified by recrystallization. (Berzelius' Lehrbuch der Chemie, 5th ed., 3, 1194; Bibl. Univ., 46, 1843, 357.) W. WALLACE: 79.74 (O = 16). Determined by analysis of arsenic ter-bromide, by titration with argentic nitrate, according to the method of Pelouze, (see arsenic, Pelouze's determination.) Three experiments were made, giving a mean of 79.738; extreme difference, 0.051. As = 75; Ag = 107.97. The arsenic and bromine were directly combined, and the compound was purified by fractional distillation and recrystallization. (Phil. Mag., (4,) 18, 1859, 279.) J. DUMAS: 80 (O 16). Determined by three experiments on the conversion of argentum bromide into chloride in a current of dry chlorine. The mean is 80.03; the extreme difference is 0.18. Silver is taken at 108, and chlorine at 35.5. The argentum bromide was prepared with bromine free from iodine, and was purified from chlorine by digestion with argentum bromide. (Annal. de C(hemie et de Physique, (3,) 55, 1859, 162.) J. S. STAS: 79.952 (O = 16). Four complete syntheses (the weight of each of the constituents, and of the compound being determined) were made of argentum bromide, a known weight of silver being converted into sulphate, and precipitated with a known weight of bromine which had been converted into hydrobromic acid. The mean result was that 100 Ag = 74.0805 Br; with an extreme difference of 0.004. Two analyses of argentic bromate, made by reducing the salt in suspension with sulphurous acid, gave for the molecular weight of the bromide 187.84, and 187.90, mean 187.87. A comparison of these data gives Br = 79.940. [This, I think, must be a misprint for 79.949.] Fourteen experiments were made on the equivalence of KBr and Ag by Pelouze's method, (see CADMIUM. 23 As, Pelouze's determination.) The mean result was that 100 Ag 110.345:KBr; extreme difference, 0.029. This gives Br = 79.958 for Ag = 107.93, and K = 39.137. The bromate of silver was prepared from potassic bromate and silver salts. For the preparation of Ag see Stas' determination of it. The potassic bromate was prepared by the action of chlorine on a mixture of KBr and KHO. The bromide was prepared by the action of heat on bromate, by treating bromine with KHO, and in other ways. No reagents were probably ever prepared with such care as those employed in this and the accompanying determinations. The weights are all in vacuo. (Stas, Untersuch. iiber Chem. Proport., Leipzig, 1867.) CADMIUM. Regnault, Kopp, and Bunsen have determined the specific heat of cadmium, which corresponds to an atomic weight of 112. Deville and Troost determined the density of cadmium vapor at above 10000. It answers to an atomic weight of 114. (Gmelin-Kraut, 1. c.; L. Meyer, 1. c.) F. STROMEYER: 111.48 (O = 16); 696.767 (O = 100). Stromeyer found that 100 parts of cadmium combine with 14.352 parts of oxygen to form the oxide. (Berzelius' Lehrbuch der Chemie, 5th ed., 3, 121 9; Schweigger's Journ., 22, 1818, 362.) T. THOMSON: 112 (O = 16); 700 (O = 100). Thomson says that he has shown this to be the true value by analysis of the sulphate in two different states. (System of Chem., 7th ed., 1, 1831, 555.) K. voN IIAUER: 112 (O - 16); 700 (O = 100). Determined by nine experiments on the reduction of cadmium sulphate to sulphide in a current of hydrogen sulphide under pressure. The mean of the experiments gave Cd = 55.999; extreme difference, 0.16. Von Hiauer took S = 16. The sulphate was purified by repeated recrystallizations and by conversion into oxide. It was dried at 200~. The sulphide was in each case carefully examined for undecomposed sulphate. (Erdmann's Journ. fiir Prak. Chem., 72, 1857, 346.) 24 ATOMIC WEIGHT DETERMINATIONS. J. DUMAS: 112.24 (O = 16). Determined by six experiments on the titration of cadmium chloride with argentic nitrate. The mean of all the experiments was Cd - 56.12; extreme difference, 0.49. The third experiment varies considerably from the rest, and Dumas seems inclined to omit it in the average. If it is left out, the mean becomes 56.06; extreme difference, 0.29. Dumas takes C1 -= 35.5; Ag = 108. The cadmium chloride was prepared in two lots by solution of cadmium in chlorhydric acid, evaporation and melting for several hours in a current of chlorhydric acid gas. (Annal. de Chinie et de Physique, (3,) 55, 1859, 158.) E. LENSSEN: 112.06 (O = 16). Three experiments were made on the decomposition of cadmium oxalate, the salt and the resulting oxide being weighed. The mean result was Cd = 56.03; extreme difference, 0.19. C - 6. The oxalate was prepared from pure chloride by precipitation with oxalic acid, washing and drying at 150~. It was carefully tested, and was found to be anhydrous. (Erdmann's Journ. fiir Prak. Chemie, 79, 1860, 281. CESIUM. The great similarity between coesium and the other alkaline metals renders the deduction of its atomic weight from its equivalent sufficiently certain. KIIRCHHOFF and BUNSEN: 123.35 (O = 16). Determined by three experiments on the analysis of the chloride with argentic nitrate. The value is the mean; extreme difference, 0.13. The cmesium was separated from the other alkalies by extracting a mixture of oxides and carbonates with alcohol. It was converted into chloride by precipitation with platinum chloride, reduction of the double chloride in hydrogen and solution. These operations were repeated until the caesium salt gave sensibly the same results after successive purifications. Its purity was also tested spectroscopically. Silver was taken at 107.94, and chlorine at 35.46. (Poggend. Annal., 113, 1861, 363.) CASIUM. 25 JOHNSON and ALLEN: 133 (O = 16). Determined by four experiments on the precipitation of caesiurn chloride with argentic nitrate. The mean result was Cs = 133.036; the extreme difference, 0.842. Ag = 107.94; Cl = 35.46. Csesium and rubidium were separated by partial crystallization of their bitartrates. The caesiumn bitartrate was converted into chloride by precipitation with platinum chloride, reduction and solution. The nitrate formed on the precipitation of the cesiunm chloride with silver was reconverted into ceasiuri chloride and redetermined, and so on. The purity of the salt was tested spectroscopically. (Silliman's Amer. Journ., (2,) 35, 1863, 96.) R. W. BUNSEN: 133 (O = 16). Determined by three experiments on the precipitation of cessium chloride with argentic nitrate.'rhe mean result was 132.99; extreme difference, 0.02. Ag = 107.94; C1 = 35.46. In order to prepare pure chloride, a mixture of caesium and rubidium salts was converted into carbonates, a little more tartaric acid was added than was necessary to form acid tartrate with the rubidium and neutral tartrate with the casium, and the mixture was exposed on a filter to the action of a saturated atmosphere of aqueous vapor. The eesium salt is deliquescent, and gradually passes through the filter, while the rubidium salt is unaffected. The caesium tartrate was turned into pure chloride by repeated precipitation with platinum chloride, reduction in hydrogen and solution. The determinations were made on the product of successive purifications, and only those were taken into consideration which were made after analysis showed a constant composition. The spectroscope was employed to test the purity of the salt. (Poggend. Annal., 119, 1863, 5.) -. MERCER: 133 (O - 16). The fact of this determination, without details, is mentioned by Frankland. (Chem. News, 8, 1863, 18.) R. GODEFFROY: 132.557 (O = 16). Derived from the mean of four analyses of mesium chloride with argentic nitrate, the extreme difference being 0.185. C -= 35.5; Ag = 108. The csesium was separated from the other alkalies by the fractional crystallization of their alumns continued until the coesium compound was 26 ATOMIC WEIGHT DETERMINATIONS. spectroscopically pure. The aluminium was removed with ammonia, the sulphuric acid with barium chloride and traces of barium with ammonium carbonate. The caesium chloride, which was not deliquescent, was dried at 150~. (Liebig's Annal., 181, 1876, 185.) CALCIUM. Bunsen has determined the specific heat of calcium. It corresponds to an atomic weight of 40. (Gmelin-Kraut, 1. c.) F. H. WOLLASTON: 40.736 (O 16); 254.6 (O = 100). Wollaston found that 43.7 parts of carbon di-oxide saturated 56.3 parts of lime. If C = 75.4, the value follows. (Phil. Trans., 104, 1814, 20.) J. J. BERZELIUS: 40.32 (0 = 16); 252.075 (O = 100). 301 parts of anhydrous calcium chloride gave 775 parts argentic chloride. If Cl = 443.28 and Ag = 1349.66 the value follows. This analysis, made in 1818, was erroneously calculated from a mistake in setting down its results and the atomic weight of Ca was taken at 256.019. (Poggend. Annal., 8, 1826, 189; and Lehrbuch der Chemie, 5th ed., 3, 1227.) J. DUMAS: 40 (O - 16). Three experiments were made on the calcination of calcium carbonate which contained 0.03 per cent. of ferric oxide and silicic acid. The weight of the residue was in mean 56.07, or, subtracting 0.03, 56.04, with an extreme difference of 0.08. These figures give almost exactly 40. The weighings are reduced to vacuum. (Paris Comptes Rendus, 14, 1842, 537.) -. SALVETAT: 40 (O = 16); 250 (O = 100). It is to be inferred from the context that this determination was made from the loss of weight ensuing on the decomposition of calcium carbonate by heat or sulphuric acid. (Pari Comptes Rendus, 17, 1843, 318.) CALCIUM. 27 C. MARIGNAC: 40.208 (O = 16); 251.3 (O = 100). Determined by precipitating calcium chloride with argentic nitrate; Ag = 1349.01; Cl = 443.2. Marignac laid no weight on this determination finding it impossible to prepare calcium chloride which did not show an alkaline reaction. The presence of caustic lime would make the result erroneously high; no doubt Berzelius' early analysis was defective from the same cause. (Berzelius' Jahresbericht, 24, 1844, 103; Bibl. Univ., 46, 1843, 367.) ERDMANN and MARCHAND: 40.007 (O = 100). Four experiments were made on the calcination of calcium carbonate enclosed in a double platinum crucible in a wind-furnace, till the weight was constant. A mean of 56 per cent. calcium oxide was found with an extreme difference of 0.05. This gives Ca = 40 for C -- 12. Two experiments were made by decomposing calcium carbonate by sulphuric acid. These gave a mean of 43.99 carbonic acid; difference, 0.02. The value taken is the mean of all experiments. The carbonate was prepared by precipitating calcic chloride with ammonium carbonate, and drying at 1600 to 1800. Confirmatory experiments were made on iceland spar. The weighings are reduced to vacuum. (Erdmann's Journ. fur Prak. Chem., 26, 1842, 472.) Berzelius maintained that Erdmann and Marchand employed material containing water, chlorine and magnesium. Erdmann and Marchand answered that there could be no magnesium and was no chlorine but that they had convinced themselves that spar is the only compound of certain and constant composition. Berzelius replied that they then admitted that their carbonate contained water. Erdmann and Marchand appealed to their experiments on spar, upon which Berzelius made experiments showing that spar, too, retains water at 200~. This Erdmann and Marchand denied and finally assert that all the carbonic acid is not driven off at any attainable temperature, and that their- results were therefore too high instead of being too low. The error they estimate to exactly cover the difference between their averages and 40. (Erdmann's Journ. fiir Prak. Chem., 31, 1844, 257; 37, 1846, 75; 50, 1850, 237.) ERDMANN and MARCHAND: 40.062 (O = 16); 250.39 (O = 100). The spar experiments referred to above. Six analyses were made as before, giving a mean of 56.028 oxide; extreme 28 ATOMIC WEIGHT DETERMINATIONS. difference 0.047. (Erdmann's Journ. fiir Prak. Chemie, 31, 1844, 268.) Another experiment, in which the absence of water was proved, gave 56.03 lime. The weighings are reduced to vacuum. (Erdmann's Journ. fir Prak. Chem., 37, 1846, 77.) J. J. BERZELIUS: 40.264 (O - 16); 251.651 (O- = 100). Five experiments were made on the conversion of caustic lime into sulphate. The value is the mean for S = 200.75; extreme difference 0.962 for O - 100. The lime was carefully purified and burnt, but Berzelius says nothing of testing it for carbonic acid, upon which Erdmann and Marchand found an objection. Berzelius expresses himself ill satisfied with the results. (Liebig's Annal., 46, 1843, 241; also Lehrbuch der Chemie, 5th ed., 3, 1228.) J. DUMAS: 40.02 (O = 16). Five experiments were made on the titration of calcium chloride with argentic nitrate. They give a mean of 20.065, but Dumnas considers only three of them as entitled to a voice. These give 20.01; extreme difference, 0.03. The calcium chloride was prepared by dissolving marble in chlorhydric acid, digestion with lime water, filtration, evaporation, treatment with chlorhydric acid and heating in a current of chlorine. For the three experiments averaged the chloride was kept melted in the current of gas for from 8 to 10 hours. Ag = 108; Cl - 35.5. (Annal. de Chimie et de Physique, (3,) 55, 1859, 129.) CARBON. The specific gravity of gaseous carbon compounds shows that the atomic weight must be nearly 12. (Gmelin-Kraut, 1. c.) Weber has shown that the specific heat of carbon at high temperatures obeys Dulong and Petit's law. F. H. WOLLASTON: 12.064 (O = 16); 75.4 (O = 100). Biot and Arago found the specific gravity of carbon dioxide 1.5196, and that of oxygen, 1.1036. Calculation from these data gives the value. (Phil. Trans., 104, 1814, 20.) CARBON. 29 J. J. BERZELIUS: earlier determinations. In 1817 Berzelius attempted to determine the atomic weight of carbon by two analyses of plumbic carbonate. [These analyses calculated for Pb = 206.926 (Stas,) give C = 11.998 and 11.984, or 74.99 and 74.90.] Considering the difference too great, he calculated the atomic weight from Biot and Arago's determination of the specific gravities of carbon di-oxide and oxygen, 1.10359 and 1.51961. Berzelius gives 75.33 as the result; [I make it 75.394.] Subsequently, (1819,) Berzelius and Dulong determined these specific gravities more accurately at 1.524 and 1.1026 whence he calculated C = 76.437. This number was accepted until Dumas showed it to be false, although in the mean time carbon di-oxide had been shown to be a condensible gas. According to Dumas, Berzelius at one time accepted a value 76.52 of which I have found no account. In Berzelius' Lehrbuch, 3, 1174, 76.48 is a misprint for 76.437. (Berzelius' Lehrbuch der Chemie, 5th ed., 3, 1197, et passim.) T. THOMSON: 12 (O = 16); 75 (O = 100). Thomson found the specific gravity of carbon di-oxide 1.52673. Assuming the specific gravity of oxygen at 1.1111, chiefly to accord with the supposition that air is a compound containing 20 per cent. of oxygen, he calculates the atomic weight of carbon at 75. (Erdmann's Journ. fur Prak. Chem., 8, 1836, 372; Records oJ General Science, by R. D. Thomson, 1836, 179.) J. DUMAS: about 12.16 (O = 16); 76 (O = 100). From analysis of well crystallized naphthaline, Dumas infers that the atomic weight of carbon cannot be so high as 76.44, and must be nearly as above. (Poggend. Annal., 44, 1838, 110.) J. J. BERZELIUS: 12.23 (O = 16); 76.458 (O - 100). One experiment was made on the decomposition of plumbic carbonate by heat, which gave C = 76.405. [If Pb = 206.926, the data give C = 12.185, or 76.157.] Another experiment was made on the oxalate, which gave C = 76.511. Berzelius regards these results as confirmatory of the value 76.438. The plumbic carbonate was prepared by precipitating the nitrate with ammonium carbonate. The oxalate was obtained by decomposing the acetate with oxalic acid. (Liebig's Annal., 30, 1839, 241.) 30 ATOMIC WEIGHT DETERMINATIONS. G. FOWNES: 12.12 (O =- 16). Determined by three analyses of naphthaline with cupric oxide, the usual precautions being observed. The value is the mean; extreme difference, 0.14. The naphthaline was purified by slow sublimation in a florence flask, and was brilliantly white. Fownes does not regard his results as conclusive as to the exact value. (Phil. Mag., (3,) 15, 1839, 62.) E. MITSCIERLICH: 12.016 (0 = 16); 75.1 (O = 100). Experiments made on the analysis of naphthaline by the ordinary method of organic analysis gave never more than 75.2, and those which seemed most accurate very nearly 75. (Mitscherlich's Lehrbuch der Chemie, 4th ed., 1, 1844, 595.) DUMAS and STAS: 12 (O = 16); 75 (O - 100). Determined by fourteen experiments on the combustion of carbon in oxygen, the resulting carbon di-oxide being weighed. In five cases natural graphite was employed, and in four graphite from charcoal pig-iron. Both were purified by treatment with acid and heating in chlorine. The necessary oxygen was developed in the combustion-tube from potassic chlorate and cupric oxide. In five experiments diamond was employed, and the oxygen was furnished from a gasometer. The oxygen was displaced by air, especially purified from carbon di-oxide by milk of lime. The products of combustion were collected in tubes filled with pumice stone moistened with sulphuric acid, Liebig potashbulbs and tubes filled with dry potash. The mean of the experiments on graphite gave C = 74.982; those on diamond gave 75.005; the extreme difference was 0.238. The observers point out that the result would not be affected by reduction to vacuum. (Annal. de Chimie et de Physique, (3,) 1, 1841, 5.) Liebig thinks that potash must have been volatilized, and says that there is no assurance that the oxygen was completely expelled by air. IIe also points out that the analyses of camphor and benzoic acid, accompanying the investigation, show an excess of carbon for C = 75. (Liebig's Annal., 38, 1841, 195.) ERDMANN and MARCHAND: 12.009 (O = 16); 75.054 (O = 100). Erdmann and Marchand repeated Dumas' and Stas' experirments. Five experiments on diamond gave C - 75.028; CARBON. 31 extreme difference, 0.38. Three experiments on natural and one on artificial graphite gave C = 75.087; extreme difference, 0.13. The number is the mean of all experiments. Erdmann and Marchand adopt 75. Calcium chloride was used in these experiments instead of sulphuric acid to avoid objections as to the possible volatility of the acid. (Erdmann's Journ. fiir Prak. Chem., 23, 1841, 159.) BERZELIUS and LIEBIG and REDTENBACHER: 12.119 (O = 16); 75.741 (O = 100). Five analyses by Berzelius of the tartrate of lead, the decomposition being effected by heat, gave 62.7431 per cent. plumbic oxide; extreme difference, 0.045. Several analyses of plumbic racemate gave a mean of 62.75 per cent. oxide; extreme difference, 0.05. The salts were prepared by fractional precipitation of plumbic acetate with tartaric and racemic acids respectively. They were dried at 100~. (Poggend. Annal., 19, 1830, 306.) From the analyses of the tartrate Liebig and Redtenbafcher calculate C = 75.771, and from the racemate 75.711, taking Pb = 1294.489 and H = 6.2394. (Liebig's Annal., 38, 1841, 137.) LIEBIG and REDTENBACHER: 12.137 (O - 16); 75.854 (O = 100). Determined by decomposing known weights of organic salts of silver in a covered crucible by heat and weighing the silver. Five analyses of each of the following salts showed that 18.6113 Ag = 28.8098 acetate; 9.6171 Ag = 16.223 tartrate; 16.2641 Ag = 27.438 racemate; 16.0596 Ag = 25.9019 malate. If Ag = 1351.607 and HI =- 6.2394, the above value for C follows, with an extreme difference for the 20 analyses of 0.765, (O = 100.) The figures are all calculated for vacuum. [If Ag = 107.93 and H = 1.0025, the average number obtained from the mean of each set of analyses gives C = 12.06865 or 75.429.] The acetate was prepared by partially neutralizing pure acetic acid with ammonia, precipitating with argentic nitrate and recrystallizing the salt from hot aqueous solution. The crystals were dried at 103~. The acetic acid was prepared from plumbic acetate. The tartrate was prepared by adding tartrate of sodium and potassium to a hot (80~ to 850) dilute solution of argentic nitrate till a small permanent precipitate was formed, and cooling the solution. The racemate was prepared from pure acid racemate of ammonium like the:tartrate. The malate was prepared from calcium 32 ATOMIC WEIGHT DETERMINATIONS. malate and argentic nitrate. The salt thus obtained was dissolved in nitric acid, and reprecipitated with ammonia added drop by drop, not to complete neutralization, washed and dried. (Liebig's Annal., 38, 1841, 139.) A. Strecker recalculated Liebig and Redtenbacher's analyses given above, independently of the atomic weight of silver, from the difference in their atomic composition, employing the method of least squares. Ile found C= 75.415 4- 0.061, or 12.066 4- 0.01. In the same way, and from the same analyses he calculated the atomic weight of silver at 1348.79, or 107.9032. [The close coincidence between this result and Stas', is certainly worthy of remark.] (Liebig's Annal., 59, 1846, 280.) Marignac repeated Liebig and Redtenbacher's experiments and got almost the same results, but, by varying the method so as to preclude loss by spirting, different ones. (Liebig's Annal., 59, 1846, 287.) Stas had the same experience as Marignac, and also ascribes Liebig and Redtenbacher's high results to loss by spirting. (Bulletin de l'Acad. Roy. des Sciences de Belgique, 16, 1849, 9.) C. MARIGNAC: 11.986 (O - 16). Determined by three analyses of the acetate of silver. The salt was decomposed by heat in a tube in such a way that the products of decomposition were forced to pass through porous silver, and loss by spirting was impossible. 100 parts of the salt were found to contain a mean of 64.664 silver, with an extreme difference of 0.005 in. vacuo. [If Ag = 107.93, these figures give the above value.] Marignac regards the analysis as a confirmation of Dumas and Stas' determination. The acetate was prepared by solution of argentic carbonate in acetic acid and successive recrystallizations. (Liebig's Annul., 59, 1846, 287; Bibl. Univ., Arch. des Sciences, 1. 1846.) Strecker believes that the silver in Marignac's determination must have retained carbon. (ibid. 284.) F. VON WREDE: 12.019 (O = 16); 75.12 (O 100). Von Wrede determined the specific gravity of carbon dioxide, taking into consideration its variation from the lawof Marriotte. He found it equal to 1.520371 +at49p 1 + at. IHe also found the specific gravity of oxygen 1.1052 and CARBON. 33 that of carbonic oxide 0.96779. Comparison gives C = 75.11 to 75.14. (Berzelius' Jahresbericht, 22, 1842, 72.) Berzelius adopted this determination. According to Gmelin-Kraut, 1, (2,) 70, Regnault's value for the specific gravity of oxygen combined with von Wrede's for carbon di-oxide gives C = 12.0037, and with that for carbonic oxide C — = 12.0105. J. S. STAS: 12.005 (O = 16); 75.029 (O = 100). Determined by passing carbonic oxide ovbr a known weight of pure cupric oxide, and weighing the carbon dioxide formed. Stas got from eight experiments C = 74.993 to 75.055. [The number taken is the mean of the results, which is misprinted in Stas' paper 75.039.] The carbonic oxide was prepared from oxalic acid by the action of sulphuric acid. It was purified from carbon di-oxide by passing through potash tubes, and from oxygen by passing over hot copper filings, and was kept in a gasometer over water, in which was dissolved a solution of stannous oxide in potash. The cupric oxide was prepared by igniting pure cupric nitrate. The carbonic acid formed in the experiments was caught in potash and sulphuric acid tubes. The amount of carbon di-oxide weighed was from 23 to 67 grammes. The weighings are reduced to vacuum. (Bulletir de l'Acad. Roy. des Sciences de Belgique, 16, 1849, 9.) GRAPHON. B. C. BRODIE: 33 (O = 16). By the action of potassic chlorate and nitric acid on graphite, Brodie obtained a compound of carbon, oxygen and hydrogen containing 11 atoms of carbon, and by the action of heat on this substance two others containing, respectively, 22 and 66 atoms. The first of these is analogous to the hydrated oxide of silicon obtained by Buff and Woehler, if Si = 21. From this fact, and the specific heat of graphite, Brodie concludes that the atomic weight of the graphitic form of C is 33. (Phil. Trans., 149, 1859, 249.) Graham-Otto points out that if Si = 28, graphon must be 44, and that, in that case, the argument from the specific heat loses its applicability. 3 34 ATOMIC WEIGHT DETERMINATIONS. CERIUM.. The specific heat of metallic cerium, as determined by W. F. Hillebrand, is 0.04479, and the atomic heat 6.18 if the atomic weight is 138. (Poggend. Annal., 158, 1876, 86.) It is well known that cerium is always accompanied in nature by lanthanium and didymium. The former was discovered in 1839, and the latter in 1843, both by Mosander. W. HISINGER: 137.93 (O - 16). According to IHIisinger, as reported by Berzelius, the lower oxide of cerium contains 14.821 O per 100 Ce, giving the atomic weight at 574.718 for O = 100, if the lower oxide is regarded as a protoxide. (Poggend. Annal., 8, 1826, 186.) T. THOMSON: 150 (O = 16). Thomson analysed the sulphate and obtained for cerium the value 625, (O = 100.) [He probably took barium = 70.] (System of Chem., 7th ed., 1, 1831, 466.) F. J. OTTO: 138.91 (O -- 16). According to Gmelin, Otto found in an approximate determination Ce = 578.8, and recorded it in his revised translation of Graham's Chemistry, 1, 1840, 222. A. BERINGER: 138.48 (O = 16). [Three analyses of cerous chloride with silver give the atomic weight of cerium at 576.375, or 92.22, if Ag = 107.93, and Cl = 35.457. Inconsistent results are given for an analysis of the sulphide.] Three analyses of the sulphate in which the oxide was determined, gave 57.4717 per cent. so-called protoxide, [or Ce = 576.31, or 92.21, if S - 32.0742.] Analysis of the formate gave Ce = 577.04 for C = 75.85. The material for the preparations was ceric oxide obtained from cerite, and purified from lanthanium by digestion with very dilute nitric acid. The lower oxide was assumed to be Ce O. (Lie.bq's Annal., 42, 1842, 134.) R. IIERMANN: 138 (O = 16). The lower oxide was assumed to be Ce O. 23.523 parts of anhydrous cerous sulphate gave 29.160 parts of barium sulphate, giving Ce =575, for 0 — 100, Ba -856.88, and S - 201.16. The salt was obtained by precipitating basic CERIUM. 35 sulphate from a sulphuric solution of the cerite oxides, and converting this precipitate into the neutral salt. (Erdmann's Journ. fiir Prak, (hem., 30, 1843, 184.) C. RAMMELSBERG: 137.93 (O = 16). Hermann states that Rammelsberg experimented on cerium salts free from lanthanium, and got Ce = 574.7, the lower oxide being supposed to contain one atom of oxygen.. [I cannot find the original paper.] (Erdmrann's Journ. fiir Prak. Chem., 30, 1843, 184.) C. MARIGNAC: 141.79 (O = 16). The result of seven experiments on the titration of cerous sulphate, prepared from basic sulphate, with barium chloride.. (Erdmann's Journ. fiir Prak. Chem., 48, 1849, 406; Bibl. Univ. Arch des Sciences, 8, 265.) Marignac subsequently made experiments which showed these results to be too high from the impurity of the barium sulphate precipitate, (see note to Turner's determination of Barium,) and that the number 575 (for O = 100 and cerous oxide Ce 0) was more probable. (Annal. de Chimie et de Physique, (3,) 38, 1853, 148.) T. KJERULF: 174.56. Kjerulf obtained, by three organic analyses of cerium oxalate, Ce = 727.33 on the protoxide theory, O = 100. The salt was prepared by dissolving cerium oxide in oxalic acid. (Liebig's Annal., 87, 1853, 12.) Bunsen points out that this must have been a basic salt. (ibid, 105, 1858, 50.) -R. BUNSEN and J. JEGEL:.138.192 (O = 16). The lower oxide was presumed to contain one atom of oxygen. In two experiments cerous sulphate was decomposed with ammonium oxalate. The sulphuric acid thus liberated was determined with barium sulphate; the cerium oxalate precipitate was decomposed by heat with the formation of eerie oxide, which was weighed and the additional oxygen, introduced by heating, determined by iodometric titration. The salt was not anhydrous; the water contents was estimated by difference. The experiments gave respectively 57.49 and 57.46 per cent cerous oxide in the anhydrous salt, or Ce = 576.3 and 575.25 if S = 200. One experiment was made on hydrous cerium oxalate. The cerous oxide was found as before; the water was determined and the 36 ATOMIC WEIGHT DETERMINATIONS. oxalic acid was estimated by difference. This gave 60.02 per cent. cerous oxide, calculated for the anhydrous salt, or Ce = 575.65. The salts were prepared from cerite as follows: the mineral was digested with sulphuric acid, the sulphates formed were leached with water and with dilute nitric acid; this solution was treated with hydrogen sulphide, chlorhydric acid was added and cerium oxalate was precipitated. The oxalate was heated with magnesia to convert the cerium into the higher oxide, which was dissolved in concentrated nitric acid. After diluting the solution, chemically pure basic sulphate was precipitated. In the preparation of cerous sulphate and oxalate oxidation was prevented by the action of sulphurous acid. (Liebig's Annal., 105, 1858, 45.) C. RAMMELSBERG: 138.216 (O = 16). One experiment on the organic analysis of cerium oxalate by heating in a current of oxygen behind copper oxide gave Ce = 575.9, (O = 100,) or 92.144, (Q = 16,) cerous oxide being regarded as Ce O. Rammelsberg does not adopt his own, but Hermann's determination. (Poggend. Annal., 108,. 1859, 44.) C. WOLF: 136.992 (O- = 16). Determined from experiments on the sulphate, prepared and analyzed as by Bunsen and Jegel. Wolf purified the basic sulphate by solution in nitric acid and reprecipitation in hot water, aided by recrystallizations. IHe found that the oftener these processes were repeated the smaller was the atomic weight resulting from the analysis. The purifi — cations were repeated until the salt was spectroscopically free from didymium, and was perfectly white, (that employed by other investigators had been yellowish or buff.) The value taken, 45.664, [or I of 136.992,] was the smallest and last value reached. The investigation was made in Bunsen's laboratory. (Silliman's Am. Journ., (2,) 46, 1868,. 53.) C. H. WING: 137.01 (O = 16). Two, experiments were made on the decomposition of hydrous cerium sulphate with oxalic acid, the cerium oxalate being converted into ceric oxide by heat. The amount of cerous oxide in the eerie oxide was calculated according to Wolf s results, giving for the atomic weight of cerium 45.64 and 45.69, S being 32. The cerium was six times recon CHLORINE. 37 verted into basic sulphate, and repeated recrystallizations were made. The salt was white and spectroscopically pure. The determination was made in Gibbs' laboratory. (Silliman's Amer. Journ. (2,) 49, 1870, 356.) D. MENDELEJEFF: 138 (O = 16). Mendelejeff' first suggested raising the atomic weight of cerium from 92 to 138. His reasons were a specific heat determination which he had made with very impure metal, and the fact that the supposed sesquioxide had never been shown to exist. He believes that the atomic weight will be found somewhat below 138, because that is the atomic weight of barium. (Liebig's Annal., suppl., 8, 1871, 186.) H. BUEHRIG": 140.648 (O = 16). Determined from ten analyses of the hydrous oxalate performed by combustion in a current of pure oxygen behind copper oxide. The water was collected in tubes filled with calcic chloride, and the carbonic acid in potash. Five experiments in which the cerium oxide was not determined gave a mean of 94.1304, on the supposition that cerous oxide contains 1 atom of oxygen and that O = 15.96, with an extreme difference of 0.0445. Five determinations in which the cerium was determined as eerie oxide gave 94.2260, with an extreme difference of 0.0431. Carbon was taken at 11.97. The mean result is Ce = 94.1782 for the above mentioned assumptions, [or 140.648 for O = 16, and on the supposition that cerous oxide is a sesqui-compound.] The oxalate was prepared from basic nitrate purified by Gibbs' method of oxidation with miniumn and nitric acid. The salt was spectroscopically pure. (Erdmann's Journ.fiir Prak. Chem., 120, 1873, 222.) CHLORINE. The density of chlorine gas and the specific heat of chlorine compounds leave no doubt that the atomic weight of this element is nearly 35.5. (Gmelin-Kraut, 1. c.) MARCET, BERZELIUS, WOLLASTON: 35.28 (O = 16). Marcet, by experimenting on the calcination of pure marble, and on the saturation of chlorhydric acid with lime, 38 ATOMIC WEIGHT DETERMINATIONS. found as the mean of many trials, that 50.77 calcic carbonate are equivalent to 56.1 calcic chloride. Wollaston, taking the equivalent of calcic carbonate at 630, and that of calcium at 255, calculates the equivalent of chlorine at 441 for O = 100. Wollaston cites Berzelius as having obtained the same number by the conversion of plumbic carbonate into chloride. (Phil. Trans., 97, 1807, 301; 104, 1814, 20.) J. J. BERZELIUS: 35.412 (O- 16); 221.327 (O0 100). The molecular weight of potassium chloride was ascertained from four experiments on the decomposition of' potassium chlorate, which on being heated lost 39.15 per cent. oxygen. This gives for the chloride 932.567, (O = 100.) 100 parts of potassium chloride were further found equivalent to 192.4 parts argentic chloride, and 100 parts of silver to 132.75 argentic chloride. The value follows. Berzelius in his Lehrbuch accepts Marignac's determination and ascribes the error of the value he had obtained to the imperfect decomposition of that portion of the chlorate which was carried off as dust during the experiment. (Poqgend. Annal., 8, 1826, 17; also Lehrbuch der Chemic, 3, 1189, 1191.) E. TURNER: 35.42 (O = 16). Turner made two experiments on the decomposition of plumbic chloride with argentic nitrate. Assuming the atomic weight of lead at 103.6, and that 100 silver = 132.8 chloride, these analyses gave C1 = 35.43 and 35.48. Turner also decomposed corrosive sublimate with calcic oxide neutralized with nitric acid and precipitated with argentic nitrate. If mercury = 201, these analyses give a maximum of 35.28, and a minimum of 35.21, of which Turner selects the largest. From calomel treated in the same way, he arrived at the value 35.35. From his experiments on the composition of argentic chloride (and apparently comparison with potassic chloride and chlorate) Turner got 35.45. The mean of the other experiments was 35.35, but Turner considers 35.42 as being the most likely value. The plumbum chloride was prepared from the carbonate, and was purified by recrystallization, as was also the corrosive sublimate. The calomel was "prepared by Mr. HIoward," and retained traces of moisture at 300~, which would make the atomic weight derived from its analysis too small. The values are for vacuum. (Phil. Trans., 123, 1833, 529.) CHLORINE. 39 F. PENNY: 35.454 (0 = 16). Six experiments on the conversion of silver into nitrate gave 100 Ag = 157.441 nitrate; extreme difference, 0.028. Twelve experiments by three different methods on the conversion of silver into chloride gave 100 Ag- 132.837 chloride. Four series of experiments on the interconversion of potassic chloride, chlorate and nitrate gave for the difference between the molecular weights of the chloride and the nitrate 26.56. Corresponding experiments with sodium salts gave the same difference 26.568. The mean combined with the data for the silver salts gives the molecular weight of argentic chloride at 143.424, and Cl = 35.454. For further details see Penny's determinations of potassium, sodium, nitrogen and silver. The weighings were calculated for vacuum. (Phil. Trans., 129, 1839, 32.*) R. PHILLIPS: 35.688 (O = 16). In order to avoid the error possibly incurred by the melting of argentic chloride, etc., Phillips mixed known and nearly equivalent quantities of silver dissolved in nitric acid, or of crystallized argentic nitrate, with ammonium chloride; filtered, washed, and precipitated the comparatively minute amount of chlorine in the filtrate with silver solution. The fusion of this small quantity could cause no loss of importance. Phillips confesses that his ammonium chloride was acid and the only conclusions he draws are that Cl 36, N - 14, O = 8 and H = 1 may be taken without considerable error if silver is 108. [The method seems to have been original and is nearly that afterwards adopted by Pelouze. The acidity of the ammonium chloride would of course give Cl too high.] (Phil. Trans., 129, 1839, 35.) C. MARIGNAC: 36.001 (O - 16); 225.007 (O = 100). Determined by passing chlorhydric acid gas over hot cupric oxide and condensing the water formed. The mean of three experiments was Cl - 450.013; the extreme difference is 0.2 for O = 100. The gas was made from recrys* This is one of the most elegant investigations of the kind to be found in chemical literature, though it scarcely receives a mention except from Stas, who accords to it the praise it deserves. Stas' wonderfully exhaustive researches were necessary to prove beyond question that chemistry has a mathematical basis, and that the atomic weights of the elements are incommensurate. Penny's investigation, taken in connection with Stas', shows that the highest degree of accuracy is not incompatible with the simplest means when they are applied with the care and acumen, without which exact results cannot, under any circumstances, be obtained. 40 ATOMIC WEIGHT DETERMINATIONS. tallized sea-salt and concentrated sulphuric acid and was dried by passing through nine tubes filled with sulphuric acid and pummice stone and with calcium chloride. The water was collected in a condenser to which drying tubes were appended. (Paris Comptes Rendus, 14, 1842, 570.) A. LAURENT: 35.468 (O = 16); 221.672 (O = 100). Determined by three analyses of chloronaphthalintetrachloride, which he found to contain 58.22; 58.29; 58.28; per cent. Cl. The mean is 58.27 from which the value follows. (Paris Comptes Rendus, 14, 1842, 456.) According to Maumene, Laurent confessed that his salt was impure, containing chlorose compounds, in Gerhardt's Comptes Rendus, 1845, 108. (Annal. de Chimie et de Physique, (3,) 18, 1846, 45.) C. MARIGNAC: 35.37 (O- =16); 221.07 (O = 100). One synthesis of argentic chloride showed that 100 silver equals 32.74 chlorine. Berzelius had found 32.75, which Marignac adopts. Marignac found by six experiments on the decomposition of potassic chlorate by heat, that the molecular weight of potassic chloride was 932.14. He tested the equivalence of potassic and argentic chlorides by precipitating the former with argentic nitrate, filtering without the use of paper through a funnel with a capillary neck. The precipitate was dried and weighed, then melted and reweighed, no loss being observable. 100 potassium chloride gave 192.33 and 192.34 argentic chloride in two experiments, or reduced to vacuum, 192.26. Hence the atomic weight is 442.13. The potassic chloride was prepared by heating chlorate which had been purified by repeated recrystallizations. (Liebig's Annal., 44, 1842, 23.) C. MARIGNAC: 35.456 (O = 16); 221.6 (O = 100). In accordance with Pelouze's suggestion, Marignac repeated his determination of the composition of argentic chloride and of the equivalence of potassic and argentic chlorides, retaining the molecular weight of potassic chloride mentioned in the last paragraph. That value was obtained from the mean of six experiments on the decomposition of the chlorate which gave the percentage of oxygen at from 39.155 to 39.167; mean 39.161. Pelouze had got, as the mean of three experiments, 39.157. (Paris Comrptes Rendus, 15, 1842, 959.) Marignac made eleven experiments on the equivalence of silver and potassium chloride by Pelouze's CHLORINE. 41 method, a known weight of silver being dissolved in nitric acid and added to a known and nearly equivalent amount of potassic chloride in solution, after which the excess was titrated with decimal standard solution. 100 parts of silver were precipitated by from 69.049 to 69.067, in mean by 69.062 chloride. 100 parts of chloride were precipitated by from 192.33 to 192.37, in mean by 192.348 silver. Five experiments were made on the composition of argentic chloride by dissolving silver in nitric acid, with precautions against loss by spirting, precipitation with chlorhydric acid, washing, drying, melting and weighing in the same vessel. 100 parts of silver gave from 132.825 to 132.844 chloride, -mean 132.84. Calculation from these data gives in vacuo Ag = 1349.01; K - =488.94; C1 = 443.20; for O - 100 [or Ag- 107.921; K = 39.115; C1 = 35.456, for 0 = 16.] (Berzelius' Jahresbericht, 24, 1844, 58; Bibl. Univ., 46, 1843, 350.) C. GERHARDT: 36 (O =16). By heating potassic chlorate in a current of oxygen Gerhardt got, when he took precautions against loss by spirting, a mean of 60.949 chloride, from which he deduces 36 for chlorine without giving further data. (Paris Comptes Rendus, 21, 1845, 1280.) Marignac shows that no data have ever been published which, in connection with Gerhardt's experiments, would give this value for chlorine. He adds further experiments of his own which, without aiming to establish more exactly the true atomic weight, prove it less than 36 (Liebig's Annal., 59, 1846, 284; Bibl. Univ., Arch. *des Sciences, 1, 1846.) E. J. MAUMENE: 35.462 (O = 16). Maumene made seven analyses of argentic chloride by reduction in a current of pure hydrogen. Five of these experiments were made with quantities less than 10 grammes, and gave a mean of 100 silver = 32.736 Cl. Two experiments were made with about 30 grammes each, and gave 100 silver equal to 32.86 and 32.853 chlorine. Maumene prefers the latter, and deduces from them for chlorine the value 443.67 or 35.494 taking silver according to his own experiments at 1350.32. [If silver is taken at 107.93 (Stas) the same analyses give 35.462.] (Annal. de Chimie el de Physique. (3,) 18, 1846, 41.) 42 ATOMIC WEIGHT DETERMINATIONS. A. LAURENT: 35.5 (O = 16); 221.88 (O = 100). A single experiment was made as follows: pure silver was weighed off and placed in a matrass, nitric and chlorhydric acids were added, the liquid was evaporated and the chloride melted. An empty test was carried on at the same time to act as tare. Silver was taken at 1350. (Paris Comptes Rendus, 20, 1849, 5.) J. DUMAS: 35.5 (O = 16). Determined by chloridizing different weights of pure silver by heating the metal in a current of chlorine. Experiments on 10 grammes and 20 grammes gave a mean of 35.5055, the difference being 0.013, for chlorine, if silver is 108. (Annal. de Chimie et de Physique, (3,) 55, 1859, 135.) J. S. STAS: 35.457 (O-=16). Stas found the atomic weight of chlorine by three independent methods: (1.) From analysis of argentic chlorate and synthesis of argentic chloride. A known weight of the chlorate was dissolved in water, precipitated with sulphuric acid to secure advantageous division of the salt, and reduced while in suspension by a slow stream of sulphurous anhydride. The chloride was washed, dried, and weighed in the flask in which it was produced. The minute amount of chloride present in the chlorate was collected and taken into consideration, and the wash-water was carefully examined for silver. Two analyses (of about 140 and 260 grammes) gave for the molecular weight of the chloride 143.383 and 143.407, mean 143.395. A variety of syntheses of argentic chloride in the wet and in the dry way showed that 100 parts silver combined with nearly 32.850 parts chlorine. Stas assumes that none of his syntheses can possibly have given too much chloride and accepts the relation stated. These data give Cl -- 35.458. (2.) From the mutual relations of potassic chlorate and chloride and argentic chloride, combined with the composition of the last. The chlorate was decomposed either by gentle heat or in the wet way with chlorhydric acid. 100 parts of chlorate were found to contain 60.846 parts chloride as the mean of eight experiments; extreme difference, 0.012, which gives the molecular weight of potassic chloride at 74.59. The relation between potassic and argentic chloride was ascertained by Pelouze's method, (see Marignac's CHROMIUM. 43 determination above.) Twenty experiments on quantities of 32 grammes, and less, of silver gave 100 parts Ag = 69.103 parts KC1; extreme difference, 0.008. These data combined with the composition of argentic chloride given above, indicate for chlorine 35.460. (3.) The composition of argentic nitrate was determined, and the difference between the atomic weights of nitrogen and chlorine. In two experiments silver was dissolved in nitric acid, the solution evaporated to dryness, and the nitrate kept melted until there was no further loss of weight. The result obtained was that 100 silver = 157.484 nitrate; difference, 0.008. From series of experiments on the relation of the chlorides of potassium, sodium, lithium and silver to the nitrates, Stas found the difference between a chloride and a nitrate from 26.586 to 26.591; mean 26.588. These data show that the atomic weight of chlorine lies between 35.455 and 35.460, and confirm the mean of all the determinations of Penny, Marignac, and Stas, 35.457. The silver for this investigation was either distilled or compared with distilled silver; it was found impossible to reduce the amount of silica in the alkaline salts below 0.002 of one per cent., it was therefore determined and allowed for; every possible method of purification by recrystallization and otherwise was resorted to to ensure purity. The weighings are all reduced to vacuum. (Stas, Unters. ilber Chem. Proport., Leipzig, 1867.) CHROMIUM. The specific heat of chromium, as determined from that of the oxide by Kopp, Regnault, and Neumann, corresponds to an atomic heat of from 5.4 to 5.98, if the atomic weight is taken at 52.4. (Gmelin-Kraut, 1. c.) J. J. BERzELIus: 56.29 (O = 16); 351.819 (O = 100). 100 parts of plumbic nitrate, on precipitation with potassic chromate, gave 98.772 parts plumbic chromate. The value follows for Pb = 1294.498, and N = 88.518. (Poggend. Annal., 8, 1826, 22.) T. THOMSON: 64 (O = 16); 400 (O = 100). 3.14 grains of metallic chromium, converted into chromic acid by heating with potash and nitre, gave a precipitate of 16.23 grains plumbic chromate. (Phil. Trans., 117, 1827, 159.) 44 ATOMIC WEIGHT DETERMINATIONS. E. PELIGOT: 52.48 (O = 16); 328 (O = 100). Peligot reached this value by a careful carbon determination of chromous acetate, produced by precipitating a dilute solution of chromium protochloride with sodium acetate, C = 75. Peligot does not regard the experiment as definitive, the salt possessing but little stability. (Annal. de Chimie et de Physique, (3,) 12, 1844, 527.) N. J. BERLIN: 52.54 (O = 16); 328.39 (O = 100). Five experiments were made on the decomposition of argentic chromate with chlorhydric acid and alcohol. The silver chloride was washed in the flask in which it was precipitated, treated with aqua regia, melted and weighed without removal. The decanted fluid and the wash-water were evaporated to dryness with excess of ammonia, treated with water and the chromium oxide filtered off, heated to redness and weighed. [Nothing is said of the recovery of any argentic chloride that might have been removed by the decantation.] The value taken is calculated from the comparison of the amounts of argentic chloride and of chromium oxide obtained, Ag = 1349.66; Cl = 443.28. The extreme difference is 1, for O - 100. The argentic chromate was prepared by adding nitrate to a solution of potassic chromate. (Erdmann's Journ. fiir Prak. Chem., 38, 1846, 145.) V. A. JACQUELIN: 50.08 (O = 16); 313 (O = 100). By washing and purifying violet chromium chloride, Jacquelain obtained a substance which he took to be the pure chloride and which was more soluble than the unpurified salt. He analysed it by melting with soda, and arrived at the above number. (Liebig's Annal., 64, 1847, 275; Revue Scient., 14, 198.) A. MOBERG: 53.563 (O =16); 334.769 (O -- 100). Moberg made twelve experiments on the decomposition,of chromium salts by heat. In two cases the sulphate dried at a low red heat was decomposed by strong ignition in a platinum crucible; the results being, 335.65 and 335.29 for chromium. Ten experiments were made on the decomposition of ammonium-chromium-alum which had been dried in a pulverized state for a long time. These determinations gave from 333.965 to 335.739. The value taken is the mean. The alum employed was prepared from pure material, and was repeatedly recrystallized. S = 200; N = 87.5. (Erdmann's Journ. fiir Prak. Chem., 43, 1848, 115.) CHROMIUM. 45 J. LEFORT: 52.97 (O = 16). Determined by fourteen experiments on the precipitation of barium with sulphuric acid from a nitric acid solution of barium chromate. The barium chromate was prepared by precipitating potassium chromate with barium nitrate and drying the precipitate at 250~. [If these analyses are calculated for barium = 137 and S = 32, they give 100 barium chromate = 60.244 barium oxide, extreme difference, 0.26, and the atomic weight as above. Lefort seems to have taken Ba _ 136.72. Berlin points out the correction which I have verified.] (Erdmann's Journ. fiir Prak. Chem., 51, 1850, 261; Journ. de Pharm. et de Chirn., 18, 27.) R. WILDENSTEIN: 53.485 (0 = 16). Determined by thirty-two experiments on the precipitation of barium chloride, desiccated at a red heat, by pure, neutral potassic chromate. The mean of these analyses gave 100 barium chromate - 81.70 barium chloride; extreme difference 0.35. Wildenstein calculates 334.48 without giving the assumption for chlorine. [If Cl = 35.457; Ba = 137, the value follows.] (Erdmann's Journ.fiir Prak. Chem., 59, 1853, 28.) F. KESSLER: 52.3 (O = 16). Kessler reached this value by comparing the oxidizing action of potassic chromate with that of potassic chlorate on arsenious acid. Six experiments were made on the oxidizing power of the chromate and twelve on that of the chlorate by a method of titration. By combining the maximum of one with the minimum of the other series, Kessler finds the atomic weight of chromium between 25.93 and 26.40; in mean 26.15, K being 39.12 and Cl = 35.45. Confirmnatory experiments were made on the oxidation of ferrous chloride in the same way. These gave a mean of 26.1. (Poggend. Annal., 113, 1861, 137; 95, 1855, 208.) M. SIEWART: 52.094 (O -= 16). Determined from the amount of chlorine in sublimed violet chromium chloride. Siewart criticises Kessler's determination and deduces from the latter's data a value 25.02. (Kopp's Jahresbericht, 14, 1861, 240; lalle, Zeitschr. fiir die Gesammt. Naturwis., 17, 530.) Kessler points out that the number 25.02 is a misprint in the Jahresbericht, and that Siewart's paper ascribes to him the value 26.02. (Poggend. Ann., 117, 1862, 352.) 46 ATOMIC WEIGHT DETERMINATIONS. COBALT. The atomic heat of cobalt as determined by Regnault is 6.27 if the atomic weight is assumed at 58.8. (GmelinKraut, 1. c.) E. ROTHOFF: 58.98 (O = 16); 368.65 (O = 100). 269.2 parts of cobalt oxide converted into neutral cobaltous chloride and precipitated with argentic nitrate gave 1029.9 argentic chloride, according to Berzelius' report. (Poggend. Annal., 8, 1826, 185.) Berzelius recalculates this analysis for Cl = 221.64 and Ag = 1349.66, and gets the value taken. (Berzelius' Lehrbuch, 3, 1220.) R. SCHNEIDER: 60.006 (O = 16); 375.04 (O = 100). Determined from four analyses of the oxalate. The carbon was determined as in organic analysis; the metal by heating a known weight of the salt first in a current of air, then in one of oxygen, and by reduction of the oxide in hydrogen. The mean of the four analyses gave cobalt at 30.003, with an extreme difference of 0.026 for C -- 6. The oxalate was prepared by converting the chemically pure cobalt of commerce into roseo-cobaltic chloride, from which the metal was again reduced, then dissolved in chlorhydric acid and carbonate precipitated, which was digested with oxalic acid. (Poggend. Annal., 101, 1857, 398.) Marignac objects to this determination that the oxalate, being insoluble, may very likely have retained portions of the carbonate which could not be removed by washing. (Bibl. Univ., Arch. des Sciences, (2,) 1, 1858, 372.) Schneider answers that he obtained nearly identical results from lots prepared at different times, and that he believes that he has convinced himself that the oxalate contained no carbonate. (Poggend. Annal., 107, 1859, 610.) Gibbs, reporting Schneider's determination, remarks: "' Very numerous and carefully made analyses of the ammonium-cobalt bases, executed in my laboratory, indicate 29.5 as the true equivalent of cobalt." (Silliman's Amer. Journ., (2,) 25, 1858, 438.) C. MARIGNAC: about 59 (O = 16). Five experiments were made on the decomposition of cobalt sulphate by heat. This salt can be readily dried without decomposition, and the acid is completely driven off by heat, but the resulting protoxide contains a slight COBALT. 47 excess of oxygen. In order to remove this excess it was melted under a known weight of an acid silicate of lead. The results for cobalt varied from 29.32 to 29.38. The sul-phate was purified by recrystallization. Marignac also experimented on the chloride. The weight of this salt varies greatly with the moisture of the atmosphere when crystallized, and attempts to desiccate it usually result in the formation of some insoluble compound. Three analyses of chloride appearing to contain one molecule of water, and dried at 1000, performed by titration with silver solution, gave cobalt at 29.42 to 29.51. Five experiments were made in the same way on chloride either melted in a current of chlorine or of chlorhydric acid gas, or calcined with ammonium chloride. These determinations gave from 29.36 to 29.42. (Bibl. Univ., Arch. des Sciences, (2,) 1, 1858, 374.) [Marignac, in another investigation in the same volume, takes Ag = 108; Cl = 35.5.] J. DUMAS: 59 (O = 16). Determined by five experiments on the titration of cobalt chloride with silver. The mean result for cobalt was 29.542; extreme difference 0.09; Ag = 108; Cl = 35.5. The chloride was prepared by dissolving pure cobalt in aqua regia, evaporating in the presence of excess of chlorhydric acid and heating to redness in a current of chlorhydric acid gas. In two of the determinations cobalt from a different lot, which had been heated in a vacuum was employed. (Annal. de Chimie et de Physique, (3,) 55, 1859, 148.) W. J. RUSSELL: 58.74 (0 = 16). Determined by fifteen experiments on the reduction of cobalt oxide in hydrogen. The value is the mean; the extreme difference is 0.19. To obtain pure cobalt oxide Claudet's salt was prepared, purified by recrystallization, etc., reduced in hydrogen, the metal dissolved in nitric acid and the resulting salt decomposed by heating in a stream of carbon di-oxide. (Chem. Soc. Journ., (2,) 1, 1863, 57.) Schneider considers that no sufficient precautions were taken to exclude air in these experiments, and that higher oxides were formed. (Poggend. Annal., 130, 1867, 310.) E. VON SOMMARUGA: 60 (O = 16). Determined by seven experiments on the reduction of purpureocobaltic chloride in a current of hydrogen. The mean of the experiments is 29.965; four of them give a 48 ATOMIC WEIGHT DETERMINATIONS. mean 29.996. The extreme difference is 0.093. The saltwas prepared by solution of the carbonate in chlorhydric acid, addition of ammonia in excess, exposure to the air, washing of the precipitate with acidulated, then with pure water and drying at 1100. A special examination showed it free from other metals. Sommaruga took Cl = 35.5; N = 14. (Erdmann's Journ. fir Prak. Chem., 100, 1867, 113; Sitz.-Bericht der k. k. Akad., 1866.) C. WINKLER: 59 (O = 16). This value is derived from the mean of five experiments on the precipitation of gold from a solution of neutral crystallized chloride of gold and sodium. The metallic cobalt employed was prepared by the reduction of purpureocobaltic chloride. The latter was made from oxide, and was purified by recrystallization. Gold was assumed at 196. The mean of the results was 29.496; extreme difference, 0.071. (Fresenius' Zeitschr. fiir Anal. Chem., 6, 1867, 22.) P. WELESKY: 58.98 (O = 16). Determined from the analysis of cobalti-cyanides, performed by drying the salt at 1000, and heating to redness, first in a current of oxygen then of hydrogen. Four experiments with phenylammonium-cobalti-cyanide gave cobalt at from 29.38 to 29.59. Two experiments with ammoniumcobalti-cyanide gave from 29.46 to 29.55. Mean, 29.48; extreme difference, 0.21. A single experiment by Winkler's method gave 29.42. (Berlin, Bericht der Chem. Ges., 2, 1869, 592.) W. J. RUSSEL: 58.76 (O = 16). Determined by the amount of hydrogen set free by the solution of cobalt in hydrochloric acid. The value is the mean of 2 (or 4?) trials. The cobalt employed was that reduced by Russel in his former experiments on the same atomic weight. (Chem. News, 20, 1869, 20.) R. H. LEE: 59.10 (O =16). Determined by analysis of cobalti-cyanide salts. They were decomposed in a crucible by heating from above. The carbon separated was burned off in air and then in oxygen, and the metallic oxide reduced in hydrogen. Six experiments on the strychnine salt gave a mean of 59.05. Six experiments on the brucine salt gave 59.15. Six experi COPPER. 49 ments, made with especial care, on the reduction of purpureo-cobaltic chloride by hydrogen gave 59.09. (Reported by Gibbs. Berlin, Bericht der Chem. Ges., 4, 1871, 789.) COPPER. Regnault, Kopp, and others have determined the specific heat of copper. It corresponds to an atomic heat of about 6 if the atomic weight is taken at 63.3. (Gmelin-Kraut, 1. c.) 1R. CHENEVIX: F. H.'WOLLASTON: 64 (O = 16); 400 (O = 100.) Chenevix found 20 parts of oxygen equivalent to 100 parts of copper, whence Wollaston deduces the atomic weight. (Phil. Trans., 104, 1814, 21.) J. J. BERZELIUS: 63.296 (O = 16); 395.6 (O = 100). Determined by two experiments on the reduction of cupric oxide with hydrogen, which gave 395.695 and 395.507. The water was not weighed. (Poggend. Annal., 8, 1826, 182; and Lehrbuch, 3, 1216.) ERDMANN and AARCHAND: 63.456 (O = 16); 396.6 (O = 100.) Determined by four experiments on the reduction of large quantities of cupric oxide in a current of hydrogen. The hydrogen was displaced by air after the completion of the reduction. The weight of the oxide and of the copper were reduced to vacuum, but not that of the weights employed. To obtain pure cupric oxide, pure vitrol was prepared and electrolytically decomposed. The copper thus obtained was dissolved in nitric acid, and the nitrate decomposed by heat. The value is the mean; the extreme difference is 0.056 for O = 8, or 0.112 for O = 1.6. (Erdm. Journ. fiur Prak. Chem., 31, 1844, 389.) Berzelius points out that these analyses vary among themselves much more than his own. IHe makes the difference somewhat greater than it really is by neglecting the reduction to vacuum. (Ibid., 37, 1846, 72.) Hampe shows that these analyses, correctly calculated, give Cu -= 63.46. (Zeitschr. fiir Berg Hiitten-und-Sal- Wesen im Preus. St., 21, 1873, 261.) 4 50 ATOMIC WEIGHT DETERMINATIONS. J. DUMAS: 63.5 (O 16). Dumas says that experiments on the reduction of cupric oxide and on the sulphidation of copper have shown him that the atomic weight of copper lies between 31.5 and 32, near 31.75, but that his experiments cannot be regarded as decisive. (Annal. de Chimie et de Physique, (3,) 55, 1859, 129.) MILLON and COMMAILLE: 63.128 (O = 16); 394.55 (O = 100). These (three) experiments were in most respects a repetition of Erdmann and Marchand's. The value is the mean; the extreme difference is 0.49 for O = 100, or 0.0784 for 0 = 16. The sulphate was prepared free from iron or zinc by dissolving copper in ammoniacal sulphate or nitrate. The oxide was obtained by heating the nitrate. (Paris Comptes Rendus, 56, 1863, 1249; and 57, 1863, 145.) Fresenius sees no reason for preferring this to Erdmann and Marchand's value. (Fresenius' Zeitschr.fiir Anal. Chem., 2, 1863, 474.) W. HAMPE: 63.3296 (O = 16). In three experiments cupric oxide was reduced in a current of hydrogen with all possible precautions. The hydrogen was displaced by air before weighing, though it was shown by experiment that porous copper does not condense hydrogen. The metal was heated till incipient melting was observed. The reduction and melting were repeated without altering the weight. Hampe attempted to control his results by reconverting the metal into oxide, but was unable to effect complete oxidation. The water produced by the reduction was found to be perfectly pure. The mean result was Cu = 31.6696, maximnum, 31.6729, minimum, 31.6648. The oxide was prepared from metallic copper. To obtain pure metallic copper, sulphate free from bismuth was electrolytically decomposed, the finely divided metal well washed, then melted, firstin a current of carbon di-oxide, afterwards in hydrogen, and then again in carbon di-oxide. From the metal, basic nitrate was formed and from this salt, by heating first in air and then in oxygen, oxide. In two experiments the atomic weight of copper was determined by decomposing cupric sulphate by electrolysis, and weighing the metal. The residual fluid was evaporated, and a minute amount of copper, which had escaped decomposition, was DIDYMIUM. 51 recovered and determined as sulphide. For S - 16.037 and O-= 8, these experiments gave Cu =- 31.6577 and 31.66. The value taken is the mean of the two series. All weighings were reduced to vacuum. (Zeitschr. fur Berg Hiittenund Sal.- Wesen imn Prets. St., 21, 1873, 260.) DIDYMIUM. W. F. Hillebrand found the specific heat of this metal 0.04563, which corresponds to an atomic heat of 6.60 for an atomic weight of 144.78. (Poggend. Annal., 158, 1876, 78.) C. MARIGNAC: 148.8 (O = 16); 930 (O = 100). Determined by decomposing disulphate with barium chloride. Assuming the lower oxide as a prot-oxide, he calculated the atomic weight at 620. As Marignac was not confident of the purity of his salt, and subsequently became certain that the method was untrustworthy, details are unnecessary. (Liebig's Annal., 71, 1849, 313.) C. MARIGNAC: 143.81 (O = 16); 898.8 (O = 100). Five experiments were made on the sulphate by decomposition with ammonium oxalate. The didymium oxalate was heated to redness, and the resulting oxide weighed. On the assumption that the oxide was protoxide, these determinations gave a mean of 598.2 for Di, with an extreme difference of 2.5. Three experiments were made on the chloride, the insoluble oxychloride, which is unavoidable in drying the salt, being separated. The chlorine was determined with silver, and the Di as in the previous experiments. These determinations gave Di at 600.2, with an extreme difference of 5.2 for Cl = 443.2 and S - 200. The salts were prepared from cerite. The cerium was extracted by treatment at first with dilute and afterwards with concentrated nitric acid. The sulphates of Di and La were separated by partial precipitation with oxalic acid and by partial recrystallization. (Anna!. de Chimie et de Phys., (3,) 38, 1853, 148.) R. IIERMANN: 142.44 (O = 16); 890.25 (0 = 100). In one experiment sulphate which had been heated to a low red heat, was dissolved, decomposed with ammoniuni 52 ATOMIC WEIGHT DETERMINATIONS. oxalate, the precipitate incinerated and the oxide weighed. The result was Di = 594.46, on the prot-oxide hypothesis, for S = 200. In one experiment the chloride was decomposed with argentic nitrate, oxychloride being filtered off and allowed for, and the argentic chloride weighed. This experiment gave Di = 592.54 for C1 = 443.2. For the preparation of the salt see Lanthanium. (Erdmann's Journ. tiir Prak. (helm., 82, 1861, 387.) H. ZSCHIESCHE: About 144 (O = 16). In five experiments the sulphate was exposed to a white heat until the weight became constant and the oxide on being tested showed no traces of sulphur. The results varied from Di = 46.585 to 48.08, probably, Zschiesche thinks, on account of the presence of La. S =16. Di was separated from La by the partial precipitation of the nitrates with oxalic acid, the first portion falling being redissolved,. and the partial precipitation repeated twenty times. (Erdmann's Journ. fur Prak. Chem., 107, 1869, 74. C. ERK: 142.695 (O = 16). The sulphate was decomposed with ammonium oxalate, the oxalate incinerated and the oxide weighed. The sulphuric acid was also precipitated as barium salt, and weighed. Three experiments gave a mean of Di = 95.13, on the prot-oxide hypothesis, with an extreme difference of 0.78. The Di salt was found to contain yttrium which was removed by repeated fractional precipitation with sodium sulphate. This re-agent precipitates a double salt of Di and sodium. The purification was continued until the atomic weight became constant. (Kopp's Jahresbericht, 1870, 319, Jena'sche Zeitschr, fiir Med. und Nat., 6, 299.) Casselmann thinks that the salt may still have retained yttrium, and Fresenius objects to the barium sulphate determination on the well-known grounds. (Eresenius' Zeitschr, 10, 510.) D. MENDELEJEFF: 138 (O = 16). From the analogy between Di and cerium and other elements, and from the fact that it forms two oxides, Mendelejeff believes that its lower oxide is a sesqui-oxide, and its atomic weight 138. Mendelejeff points out that an error is to be apprehended in the received values from the fact that we have no guarantee of the pureness of Di salts except recrystallization. (Liebig's Annal. Suppl. 8, 1871, 190.) ERBIUM. 53 P. T. CLEVE: 147.01 (O = 16). Determined by the conversion of didymium oxide into sulphate. The number is the mean of six experiments; extreme difference 0.58. The Di was separated from lanthanium by repeated precipitations of basic nitrate from nitric acid solution, conversion into formate and decomposition of this salt by heat. (Kopp's Jahresbericht, 1874, 259. Bulletin Soc. Chimique, (2,) 21, 246.) W. F. HILLEBRAND: 144.78 (O = 16). Determined by one experiment on the conversion of metallic Di into nitrate, and then, by heat, into oxide. The impurities were determined. The metal was reduced electrolytically from the chloride. (Poggend. Annal., 158, 1876, 78.) ERBIUM. The physical and chemical analogies of the salts of this element have led Mendelejeff (Liebig's Annal., Suppl. 8, 1871, 195,) and P. T. Cleve (Kopp's Jahresbericht, 1874, 260; Bulletin Soc. Chimique, (2,) 21, 344,) to regard it as triatomic, and its atomic weight as about 170. M. DELAFONTAINE: 113.04 (O = 16). M. Delafontaine investigated gadolinite by Mosander's method, and obtained besides yttrium, two substances which he regarded as erbium and terbium. From the sulphates, in which he supposed the metals to exist as protoxides, he determined erbium at 496 and terbium at 471 for O -- 100. Popp (Liebig's Annalen, 131, 189,) and Bunsen and Bahr (ibid, 137, 1,) have shown that Mosander's method gives only mixtures. Delafontaine's terbium is thought to have been chiefly the erbium of other chemists. (Liebig's Annual., 134, 1865, 108.) BAHR and BUNSEN: 168.9 (O = 16). A known weight of erbium oxide was treated with a very slightly excessive quantity of sulphuric acid; the solution evaporated and the excess of acid driven off at as low a temperature as possible. The increase of' weight indicates 112.6 for S = 32. The oxide was prepared from gadoli 54 ATOMIC WEIGHT DETERMINATIONS. nite. The mineral was decomposed with chlorhydric acid, and the earths precipitated with oxalic acid. The oxalates were converted into nitrates, the cerium metals separated with potassic sulphate, and calcium and magnesium with ammonia. If the nitrates of yttrium and erbium are dissolved in boiling water, basic erbium nitrate with some yttriumrn crystallizes out, leaving yttrium nitrate with some erbium in solution. The process of partial crystallization was continued as long as the atomic weight of the erbiumn salt continued increasing. Bahr and Bunsen believe, however, that the atomic weight may be some hundredths higher. The salt was spectroscopically free from didymium. (Liebig's Annal., 137, 1866, 2.) P. T. CLEVE and 0. M. HOEGLUND: 170.55 (0 = 16). Determined from four syntheses of the sulphate, giving 113.7 on the diatomic hypothesis. The oxide was purified by heating the nitrates, etc., according to Berlin. (Blomstrand in Berlin,Ber. der Chem. Ges., 1873, 1467; Bull. Soc. Chimique, 1873, 193 and 289.) FLUORINE. Dumas and Peligot and others have determined the vapordensity of a number of fluorine compounds. They correspond to an atomic weight of about 19. (L. Meyer, 1. c.) H. DAVY: 18.86 (O = 16). Determined by the conversion of Derbyshire spar into sulphate. 100 parts of spar gave a maximum of 175.2 parts calcic sulphate. [If S = 32; Ca = 40; the value fbllows.] (Phil. Trans., 104, 1814, 64.) J. J. BERZELIUS: 18.85 (O = 16). Determined by conversion of calcic fluoride into sulphate. 100 parts fluoride gave, in mean of three experiments, 175 parts sulphate; extreme difference, 0.2. [If S = 32; Ca = 40; the value follows.] (Poggend. Annal., 8, 1826, 18, and Lehrbuch, 3, 1196.) GALLIUM. 55 P. LOUYET: 19 (O = 16). Determined by six experiments on the conversion of fluorspar into calcic sulphate. The mean result was 100 parts spar equal 174.36 sulphate, with an extreme difference of 0.3. Spar from Derbyshire was pulverized, digested with chlorhydric acid, and the foreign matter removed by lutration in water. It was completely dissolved in sulphuric acid, the excess of which was driven off by heat continued till a constant weight was obtained. S = 200; Ca = 250. (Erdmann's Journ. fur Prak. Chem., 47, 1849, 104; Annal. de Chim. et de Phys., (3,) 25, 1849, 291.) E. FREMY. This chemist says that his analyses essentially confirm Berzelius' determination. (Annal. de Chimie et de Phys., (3,) 47, 1856, 27.) J. DUMAS: 19 (O = 16). Determined by the conversion of fluorides into sulphates. A single experiment on the conversion of calcic fluoride gave 18.96; two experiments on sodic fluoride, 19.06; and two on potassic fluoride, 18.99. The mean is 19.01; extreme difference, 0.12. Ca - 20; Na = 2S; K - 39; S = 16. The alkaline salts were well crystallized and were fused before use. (Annal. de Chim. et de Phys., (3,) 55, 170.) S. DE LuccA: 18.96 (O = 16). Determined by four experiments on the conversion of a pure spar from Gerfalco into sulphate. The extreme difference was 0.15. The decomposition was very difficult. The loss on ignition and the residue left on evaporation of the acid employed were taken into consideration. [S apparently 16; Ca = 20.] (Paris Comptes Rendus, 51, 1860, 299.) GALLIUM. Berthelot has determined the specific heat of gallium at 0.079 corresponding to an atomic heat of 5.52, if the atomic weight is 69.9. (Paris Comptes Rend., 86, 1878, 786.) 56 ATOMIC WEIGHT DETERMINATIONS. L. DE BOISBAUDRAN: 69.9 (O = 16). This chemist "has prepared several chlorides, [samples of chloride?] several bromides, and several anhydrous iodides of gallium. He has determined the atomic weight of gallium, and found it 69.9, (mean of two experiments.)" (Paris Comptes Rend., 86, 1878, 756.) GOLD. Dulong and Petit and Regnault have determined the specific heat of gold. It corresponds to an atomic weight of about 200. (Gmelin-Kraut, 1. c.) J. J. BERZELIUS: 196.4 (O - 16). Determined by the amount of mercury necessary to precipitate a known weight of gold from solution of chloride. 142.9 mercury were found equivalent to 93.55 gold. [If HIg,= 200, this gives Au = 196.397.] (Poggend. Annal., 8, 1826, 178.) T. THOMSON: 200 (O 16). This value is derived from a somewhat inaccurate experiment on the reduction of auric chloride by ferrous sulphate. (Edinb: Trans. ]Roy. Soc., 11, 1831, 26.) J. J. BERZELIUS: 196.73 (O = 16). Determined by five experiments on the relative amount of gold and of potassic chloride in the residue obtained by heating the double chloride of the two metals in an atmosphere of hydrogen. [Calculated for KCl = 74.594, (Stas,) these experiments give a maximum of 196.79, minimum of 196.63 and a mean of 196.727. The atomic weight derived from the first experiment is misprinted in the Lehrbuch, as is the mean in the Jahresbericht.] (Berzelius' J-ahresbericht, 25, 1846, 41; and Lehrbuch, 3, 1845, 1212.) A. LEVOL: 196.26 (O0 - 16). A known weight of gold was converted into chloride, and this salt decomposed in boiling solution by a current of pure, washed sulphurous acid. The sulphuric acid formed HYDROGEN. 57 was precipitated as barium salt, and the atomic weight calculated by comparison of the gold employed and the barium sulphate obtained. 1000 gold gave 1782 sulphate. [If the atomic weight of S - 32.0742, and that of Ba = 137.08, the above value follows.] (Annal. de Chimie et de Phys., (3,) 30, 1850, 355.) HYDROGEN. The density of hydrogen as determined by a great number of investigators, especially Regnault, is about -1- of that of oxygen. If oxygen is 16, the atomic weight of hydrogen is consequently about 1. The atomic weights of the elements are compared either with that of oxygen or with that of hydrogen. The main advantage of assuming hydrogen as unity is the simplicity of the approximate values expressed in terms of the atomic weight of this element. The hypothesis of Prout has also had much influence in giving currency to this unit. The advantages of oxygen as a standard of comparison consist in the fact that it combines with all the elements, except fluorine, and in the superior accuracy of the determination of its specific gravity. The percentage variation between Regnault's determinations of the specific gravity of hydrogen was thirty-six times as great as occurred in his experiments on oxygen. Unnecessary complication in the approximate values of the atomic weights is as well avoided by assuming oxygen at 16 as by taking hydrogen at 1. These reasons for the adoption of the atomic weight of oxygen as a standard of comparison appear to me conclusive, and accordingly all values in this paper have been reduced to O = 16. F. H. WOLLASTON: 1.06 (O = 16); 6.64 (O = 100). Gay-Lussac and Humboldt having shown that two volumes of hydrogen and one of oxygen form water, and Biot and Arago having determined the specific gravity of these gases, Wollaston calculated the above atomic weight. (Phil. Trans., 104, 1814, 20.) BERZELIUS and DULONG: 0.9984 (O = 16); 6.24 (O = 100). Determined by three experiments on the reduction of cupric oxide by hydrogen. The hydrogen was made from 58 ATOMIC WEIGHT DETERMINATIONS. pure materials, and passed through a solution of litharge in potash, and over a coarse powder of caustic potash before use. The resultant water was caught in calcic chloride and weighed. The determination was also confirmed by experiments on the specific gravity of oxygen and hydrogen. The minimum result for hydrogen was 0.9934,. the maximum 1.0086. (Thomson's Annals of Phil., 2, 1821, 48.) T. THOMsON: I (O = 16); 6.25 (O -100). Thomson found the Sp. Gr. of H - 0.0694. Taking that of O as 1.1111 on theoretical grounds (the supposed compound nature of air, etc.,) he calculates the above value. (Erdmann's Journ. fiir Prak. Chem., 8, 1836, 374; Records of Gen. Sci., R. D. Thomson, 1836, 179.) J. DUMAS: 1.0012 (O - 16); 6.2575 (O = 100). Determined by nineteen experiments on the reduction of cupric oxide with pure hydrogen. The gas was made from pure materials and was passed through solutions of plumbic nitrate and argentic sulphate, and over potash, and dried with cold sulphuric acid or with phosphoric acid. The weighings of the oxide and of the reduced copper were made in vacuo. [Dumas corrected the results obtained for the air contained in the sulphuric acid, but does not explain how he estimated it, while certain other possible corrections are not mentioned.] The mean of the corrected results is 12.515. The extreme difference is 0.09 for O - 100. Without the correction for absorbed air the mean is 12.533, [or 1.00264]; maximum 12.583; minimum 12.481. (Paris Comptes Rend., 14, 1842, 537.) ERDMANN and MARCHAND: 1.0016 (O = 16); 6.26 (O = 100). Determined by eight experiments on the reduction of cupric oxide with hydrogen, the number is the mean of the results. In four of the experiments the correction for vacuum was calculated. These gave H = 12.548; extreme difference, 0.067. In four experiments the weighings were made in vacuo. These gave a mean of 12.492, with an extreme difference of 0.015. The oxide employed was either copper scale or was produced from cupric nitrate. The hydrogen was made from pure zinc and sulphuric acid, and was purified with potash in solution and in lumps, mercuric chloride, sulphuric acid, and chloride of calcium. In the INDIUM. 59 last five experiments the gas was also passed over red-hot copper to remove traces of oxygen.) (Erdmann's Journ. fiir Prak. Chem., 26, 1842, 461.) J. S. STas: 1.0025 (O = 16). From all the investigations that have been made on the specific gravity of the gases, the composition of water, etc., Stas is inclined to believe that the atomic weight of hydrogen cannot be less than above. Stas found that 100 silver were equivalent to 49.5973 ammonium chloride. [If N - 14.044, and C1 = 35.457, this relation would give II - 1.0074.] (Slas, Untersuch. iiber. Clhem. Prop., Leipzig, 1867.) J. THOMSEN: 1.0025 (O = 16). Thomsen made three experiments on the oxidation of a known volume of hydrogen by cupric oxide, and five experiments onl the combustion of a known volume of hydrogen in oxygen, which proved that 2 litres of hydrogen gave 1.6082 granmmes of water under normal conditions, and at latitude 45~. According to Regnault, 1 litre of oxygen and 2 litres of hydrogen would weighll 1.6084 grammes. HIence 1 volume oxygen and 2 volumes hydrogen formr water; and if H - 1, O = 15.96, [or if O = 16, IH - 1.0025.] (Berlin, Ber. der Chem. Ges., 3, 1870, 928.) INDIUM. Bunsen found the specific heat of In 0.565 and 0.574, which correspond to an atomic weight of about 114. (Poggend. Atnnal., 141, 28.) F. REICH and T. RICHTER: 111.39 (O = 16). In one experiment pure indium was dissolved in nitric acid, the oxide precipitated with ammonia and weighed. This experiment gave In = 463.4 for O = 100, and on the supposition that the metal was di-atomic. In a second experiment indium sulphide was dissolved in nitric acid, and the resulting sulphuric acid precipitated with barium chloride. This gave In = 464.9. The numbertaken is the mean. S = 200. The metal was prepared from the oxide. After the removal of lead, etc., with hydrogen sulphide, the oxides 60 ATOMIC WEIGHT DETERMINATIONS. of iron and indium were precipitated with ammonia, the precipitate dissolved in acetic acid and impure indium sulphide reprecipitated. This operation was repeated, and the last traces of iron were removed by partial precipitation with ammonia. (Erdmann's Journ. fir Prak. Clhem., 92, 1864, 484.) C. WINKLER: 107.754 (O = 16). Determined by decomposing the nitrate by heat, and weighing the resulting oxide. The mean result of three experiments was In- 35.918 for 0 -- 8, and assuming the univalence of the metal. Extreme difference, 0.079. Metallic indium was prepared by solution of the impure sulphide in chlorhydric acid, precipitation of indium by barium carbonate, solution in sulphuric acid, and precipitation by ammonia of the oxide which was reduced by hydrogen. [This indiumn seems to have contained iron.] (Erdmann's Journ. fiir Prak. Chern., 94, 1865, 1.) C. WINKLER: 113.439 (O = 16). In two experiments the double chloride of gold and sodium was decomposed by pure indium, giving 37.73 and 37.80 for O = 8, and assuming univalence fbr the metal. In two experiments the nitrate was decomposed by heat, giving In = 37.845 and 37.879. In one experiment the oxide was precipitated from nitric acid solution by ammonia. This experiment gave In -= 37.811. The number taken is the mean. The impure indium sulphide was purified as in Winkler's former determination with barium carbonate, but this process requires to be repeated several times. The reduction of the oxide was performed with sodium, the excess of which was removed from the regulus by cupellation in soda. (Erdmann's Journ. fiir Prak. Chem., 102, 1867, 282.) R. BUNSEN: 113.76 (O = 16). Determined by converting metallic indium into oxide by means of nitric acid and heat. He seems to regard the experiment only as confirmatory of Winkler's. The metal was the same which served for the determination of the specific heat, and was carefully tested for all impurities. (Poggend. Annal., 141, 1870, 28.) IODINE. 61 IODINE. Dumas determined the specific gravity of iodine vapor. It answers to an atomic weight of about 127. (Annal. de Chim. et de Phys., 33, 1826, 337.) L. J. GAY-LUSSAC: 123.9 (O - 16). 100 parts of iodine were found equivalent to 26.225 parts of zinc. [If Zn = 65, these figures give the atomic weight at 123.9.] (Poggend. Annal., 14, 1828, 559; Annal. de Chimie, 91, 1814, 5.) W. PROUT: 126 (O -- 16). Prout found 100 parts of iodine equivalent to 25.8 parts of zinc. [If Zn = 65, this gives I = 125.97.] (Thomson's Annals of Phil., 6, 1815, 323.) T. THOMSON: 124 (O = 16); 775 (O = 100). Thomson found 20.5 potassic iodide = 19.75 zinc iodide, = 20.75 plumbic nitrate. [If K = 39.1, and plumbic nitrate 331, the relation given leads to an atomic weight of 124.41.] Thomson thinks that his iodine may have been somewhat impure, as he purified it only by sublimation. (Thomson's System of Chem., 7th ed., 1, 1831, 81.) J. DUMAS: 126.13 (O = 16). Dumas determined the density of iodine vapor at 8.716 for air = 1. [Referred to the molecular weight of oxygen, this density gives the above number for the atomic weight.] Durnas thinks it probable that it can be more accurately determined by analysis. (Annal. de Chim. et de Phys., 33, 1826, 337.) J. J. BERZELIUS: 126.26 (O = 16); 789.14 (O = 100). Determined by decomposing a known weight of argentic iodide in a current of chlorine, melting the chloride and expelling free chlorine by atmospheric air. The number is the mean of two experiments; difference, 0.01. Ag = 1351.607; Cl = 442.653. The iodide was prepared by precipitation from a solution of potassic iodide with argentic nitrate. The first portion of the precipitate was set aside as possibly contaminated with chlorine. (Poggend. Ann., 14, 1828, 562.) 62 ATOMIC WEIGHT DETERMINATIONS. C. MARIGNAC: 126.844 (O = 16). In five experiments a known weight of silver was dissolved in nitric acid and precipitated by a known amount of potassic iodide according to Pelouze's modification of Gay-Lussac's method. The mean result was 100 Ag =- 153.74 KI in air; extreme difference, 0.14. Stas has recalculated this result for Ag-= 107.93, and K = 39.137. The atomic weight so found is, in vacuo, 126.847. In three experiments a known weight of silver was dissolved and precipitated as iodide; mean result, 100 Ag - 217.511 iodide. Extreme difi[rence, 0.04. From these data Stas gets I = 126.84. The iodine was purified by recrystallization as potassic iodate. The methods employed by previous experimenters were ineffectual. (Berzelius' Jahresbericht, 24, 75; Bibl. Univ. de Generve, 46, 1842, 367; also, Stas, Untersuch. iiber Chem. Prop., 153.) E. MILLON: 126.07 (O = 16); 787.915 (O - 100). Three experiments were made on the decomposition of potassic iodate. The mean loss of oxygen was 22.473 per cent; extreme difference, 0.03. If K =- 488.94, this gives I = 1580.93. In three experiments argentic iodate, which had been dried for a long time at 2000, was employed, which lost 17.0467 per cent. oxygen; extreme difference, 0.03. If Ag - 1349.01, these data give I = 1570.73. [Berzelius cites this as an atomic weight determination; Millon, however, seems to have regarded it only as a confirmation of Berzelius' number.] Millon prepared pure iodine by passing a current of chlorine through a solution of KI till the precipitated I was redissolved, and reprecipitating with an excess of KI. (Annal. de Chim. et de Phys., (3,) 9, 1843, 407.) V. A. JACQUELIN: 125.6 (O = 16); 785 (O - 100). Determined by the analysis of iodic acid with silver. The acid was prepared by the oxidation of iodine with nitric acid of sp. gr. 1.5. The purity of the preparation does not seem to have been tested. Ag = 1351. (Erdmann's Journ.fiir Prak. Chem., 51, 1850, 458; Annal. de (ihim. et de Phys., (3,) 30, 1850, 332.) J. DUMAS: 127 (O 16). Determined by the conversion of argentic iodide into chloride in a current of dry chlorine. Two experiments gave 127.04 and 127.01 for Ag - 108; C1 = 35.5. In Gmelin-Kraut's Hanldbuch these data are recalculated for Ag = IODINE. 63 107.93 and C1l 35.457, giving I = 126.941 and 126.928. The argentic iodide used was prepared from zinc iodide which had been prepared from iodine in large crystals. The argentic iodide was fused. (Annal. de Chim. et de Phys., (3,) 55, 1859, 163.) J. S. STAS: 126.851. Stas ascertained the molecular weight of argentic iodide as follows: In two complete analyses, a known weight of argentic iodate was decomposed by heat in a current of pure, dry nitrogen. The oxygen set free was caught by hot copper and weighed, as well as the residual argentic iodide. In one experiment argentic iodate was dissolved in ammonia, precipitated by sulphuric acid, (to secure advantageous division of the salt,) and reduced while in suspension by a slow current of sulphurous acid. The mean molecular weight reached was 234.779; extreme difference, 0.063. The samples of iodate employed were prepared: (1.) From argentic sulphate and potassic iodate, mixed boiling, the latter in excess, thorough washing and drying in air freed from organic particles; (2.) By the reaction of potassic iodate on argentic hyposulphite. The purity of the salt was carefully tested. Stas ascertained the composition of argentic iodide as follows: (1.) A known weight of argentic nitrate was precipitated by hydro-iodic acid and the argentic iodide washed, dried, and weighed in the same vessel. (2.) A known weight of Ag was dissolved in nitric acid, converted into sulphate, dissolved in very dilute sulphuric acid, and precipitated with hydro-iodic acid. The precipitate was washed at temperatures increasing up to 90~. (3.) A known weight of argentic sulphate was allowed to react on a known and nearly equivalent weight of iodine in an aqueous solution of sulphurous and sulphuric acids at 100, and in the dark,till all the iodine was taken up. The excess of iodine was titrated with silver solution, and the iodide weighed. This method was employed in two experiments. (4) differed from (3) mainly in the conversion of the iodine into ammonium iodide before bringing it into contact with argentic. sulphate. Four experiments were made by the last method. The mean composition of the iodide, as derived from all the experiments, is 100 Ag = 117.5343 iodine. From these data Stas calculates the atomic weight of I at 126.857, and 64 ATOMIC WEIGHT DETERMINATIONS. that of silver at 107.928. [The sum of these weights is not the molecular weight, and this, as well as recalculation of the data, shows that the number is a misprint for 126.851. Stas' results are, therefore, even closer to Marignac's than his memoir would indicate.] Most of the experiments were made with iodine prepared by the decomposition of nitric iodide decomposed in a large volume of water at 65~. The iodine was further purified by distillation over barium oxide and by other means. For the preparation of silver see that metal. All possible precautions were observed in the preparation of all reagents and in the conduct of the experiments. (Stas, Untersuch. 1iber Chem. Prop. Leipzig, 1867.) IRIDIUM. Regnault determined the specific heat of iridium. It corresponds to an atomic weight of about 198. (Gmelin-Kraut, 1. c.) J. J. BERZELIUS: 197.19 (O = 16). Berzelius determined this value from analysis of potassium chloro-iridiate. This salt reduced in hydrogen lost 29 per cent., the same quantity lost by the corresponding platinum salt, (vide platinum.) Berzelius originally calculated the atomic weight of the platinum metals both from the loss of chlorine of these double salts and from the relation between the metal and the potassic chloride left after reduction. In his Lehrbuch he points out the impossibility of complete desiccation, and resorts exclusively to the latter method of calculation. With respect to iridium he merely asserts that its atomic weight is the same as that of platinum, without there, or elsewhere, giving data as to the amounts of iridium and potassic chloride found in the reduced salt. It is, therefore, open to question whether he assumed the identity from the loss on reduction or not. [It Pt = Ir, and if KCl = 74.594, the value follows; see platinum.] Osmium and iridium were separated by fusion with nitre, solution, and distillation. The residue was fused with potassic chloride and sodium carbonate. On solution the iridium remains behind. This residue was repeatedly roasted and reduced to drive off osmium compounds. The potassium chloro-iridiate was formed from the pure metal. (Poggend. Ann., 13, 1828, 468; Kongl. Vet. Acad. Handl., 1828.) IRON. 65 C. E. CLAUS: W. M. WATTS: 197.6 (O = 16). Watts recalculated two analyses of potassium chloroiridiate by Claus from the loss in reduction, and for Cl 35.457, (Stas.) From one analysis he finds K- = 39.87, and Ir = 198.56; from the other K = 39.93, and Ir = 196.62. (Chem. News, 19, 1869, 302.) IRON. Regnault, Kopp and others have determined the specific heat of this metal. It corresponds to an atomic weight of about 56. ( Gmelin-Kraut, 1. c.) L. J. THENARD: F. H. WOLLASTON: 55.2 (O = 16); 345 (O = 100). Thenard determined the composition of the oxide at 22.5 O and 77.5 Fe, whence Wollaston calculates the value. (Phil. Trans., 104, 1814, 21.) J. J. BERZELIUS: 54.27 (O = 16); 339.213 (O = 100). Determined by repeated experiments on the oxidation of iron, such as is used for piano wire, with nitric acid. The carbon was determined and allowed for. Berzelius in his Lehrbuch shows that the error in this determination lay in the unsuspected presence of soluble silica and on reanalysis he found enough of it to correct the number when taken into account. (Poggend. Ann., 8, 1826, 185.) G. MAGNUS: 54.25 (O = 16); 339.06 (O = 100). Maognus' experiments were made by reducing ferric oxide in a current of hydrogen at about the temperature of boiling mercury. He regarded them simply as comfirmatory of Berzelius' number. (Poggend. Ann., 3, 1825, 84.) F. STROMEYER: 55.6 (O = 16). Determined by reducing ferric oxide at a red heat by hydrogen. The oxide is reduced only with great difficulty at a lower temperature. The mean of the experiments gave the oxygen contents at 30.15 per cent., [whence I have calculated the value.] (Poggend. Ann., 6, 1826, 475.) 5 66 ATOMIC WEIGHT DETERMINATIONS. H. CAPITAINE: 51.36 (0 -= 16); 321 (O = 100). Determined by the peroxidation of galvanically reduced iron and by measuring the hydrogen evolved on the solution of iron in sulphuric acid. (Annal. de Chim. et de Phys., (3,) 2, 1841, 126.) I. WACKENRODER: 55.48 (O = 16). Wackenroder helped Stromeyer in his reduction of ferric oxide, of which he gives the details. Hle also describes five experiments of his own, which gave the oxygen contents of ferric oxide at from 30.01 to 30.38. He took no precautions to purify his hydrogen and thinks that the loss of oxygen may have been apparently reduced. [30.195 oxygen corresponds to the above value for Fe.] (Berzelius' Jahresbericht, 24, 1844, 121; Archiv. der Pharm., 36, 1844, 22.) SVANBERG AND NORLIN: 55.97 (O = 16); 349.809 (O = 100). In seven experiments a known weight of iron was dissolved in nitric acid and the salt decomposed by heat. The operation was performed in a glass flask. The mean result in vacuo, was 349.104; extreme difference, 0.803. In seven experiments ferric oxide was reduced with purified hydrogen. The mean was Fe = 350.514; extreme difference, 0.735. The number taken is the mean of all the experiments, in vacuo. Berzelius in his Lehrbuch cites the experiments and, by neglecting the reduction to vacuum, gets a slightly different number. He also expresses a preference for the experiments by reduction. (Berzelius' Jahresbericht, 24, 1844, 121; and Poggend. Ann., 62, 1844, 270.) J. J. BERZELIUS: 56.05 (0 -= 16); 350.32 (0 = 100). Berzelius, as a check on the last determination, made two experiments on the oxidation of iron by nitric acid with special precautions against partial reduction. The number is the mean; diflerence, 0.101. The iron was melted down with glass and magnetic oxide. In his Lehrbuch he adopts the mean of these experiments and Svanberg and Norlin's reduction determinations. (Pogyend. Ann., 62, 1844, 270.) ERDMANN AND MARCHAND: 56.016 (O = 16); 350.1 (O = 100). Erdmann and Marchand made eight experiments on the reduction of ferric oxide in a carefully purified current of LANTHANIUM. 67 hydrogen. The weighings of the metal were made in vacuo to avoid possible reoxidation in displacing the gas by air. The number is the mean of the experiments; extreme difference, 1.4 for O = 100. The ferric oxide was prepared by incineration of the oxalate, moistening the residue with nitric acid and reheating. (Erdmann's Journ. fiir Prak. Chem., 33, 1844, 1.) L. E. RIYOT: 54.25 (O = 16); 339.01 (O = 100). Determined by two experiments on the reduction of pure ferric oxide in a current of hydrogen. 100 parts of oxide gave 69.31 and 69.35 parts metallic iron. (Annal. de CAim. et de Phys., (3,) 30, 1850, 188.) E. MAUMENE: 56.0016 (O = 16); 350.01 (O = 100). Maumene made six experiments by dissolving iron wire in aqua regia, precipitating with ammonia, heating the precipitate to redness and weighing. The number is the mean; extreme difference, 0.34. Maurene had convinced himself by analysis of the extreme purity of the wire. (Erdmann's Journ. fiir Prak. Chem., 51, 1850, 350.) J. DUMAS: 56.2 (O = 16). Two experiments on the precipitation of ferric chloride by argentic nitrate gave each 28.1. A single experiment by the same method on ferrous chloride which was slightly yellow, gave 28.1. An experiment made on ferrous chloride, which had been heated in a current of hydrogen and of HC1 and was colorless, but contained metallic iron, gave when the admixture was determined, 27.99. Dumas takes Ag = 108; Cl = 35.5. (Annal. de Chim. et de Phys., (3,) 55, 1859, 157.) LANTEHANIUM. W. F. IHillebrand has determined the specific heat of metallic lanthanium. It corresponds to an atomic heat of 6.23, if the atomic weight is taken at 139. (Poggend. Ann., 158, 1876, 82.) Several investigations on the atomic weight of lanthanium were made previous to Mosander's announcement of the discovery of didymium. F. J. Otto found it 108.41 shortly after its discovery, and announced it in his translation of 68 ATOMIC WEIGHT DETERMINATIONS. Graham's chemistry. (Gmelin's Handbuch, 5th ed., 1, 46.) Choubine, from analysis of the chloride and of the sulphate, arrived at 108.45. (Erdmann's Journ. fiur Prak. Chem., 26, 1842, 443.) Rammelsberg determined it from the sulphate, which was rose-colored, at 133.17. (Poggend. Ann., 55, 1842, 65.) R. Hermann found La -=144 from rose-colored sulphate. (Erdmann's Journ. fiir Prak. C/hem., 30, 1843, 198.) C. G. MOSANDER: 139.2 (O -= 16); 870 (O - 100). Mosander says that his experiments show the true value to be in the neighborhood of 680, (the metal being assumed bivalent,) but that his salts were not pure, and the deterniination of little value. (Poggend. Ann., 60, 1843, 301.) C. MARIGNAC: 141.12 (O = 16); 882 (0 = 100). Eleven experiments were made on the decomposition of the sulphate by barium chloride. The results vary greatly. Marignac wrote later (Annal. de Chim et de Phys., (3,) 38, 1853, 148) that experiment had convinced him of the incorrectness of this determination, and that the true value is about 575. (La bivalent.) (Liebig's Ann., 71, 1849, 306.) M. HOLZMANN: 139.22 (O = 16); 870.15 (O = 100). In three experiments La sulphate was decomposed by ammonium oxalate. In the filtrate from the precipitated oxalate the sulphuric acid was determined as barium salt. The oxalate was decomposed by heat, and the lanthanium oxide weighed. These experiments gave a mean of 580; extreme difference, 5.6; for bivalent lanthanium. In three experiments the iodate was decomposed by oxalic acid, the oxide determined as before, and the iodine titrated by Bunsen's method. These experiments gave a mean of 580.2; extreme difference, 5.3. S = 200; Ba = 855. In the preparation of the salts analyzed the cerium was separated by peroxidation with magnesium oxide and precipitation as basic sulphate. After the removal of yttrium by potassic sulphate, the lanthanium and didymium salts were separated, by making a saturated solution of the sulphates at a temperature of three or four degrees, and gradually raising the temperature. Lanthanium salt then crystallizes out nearly pure. The purification was repeated until the salts were not discolored when heated in an open crucible over the glass-blower's lamp. Bunsen assisted at this investigation. (Erdmann's Journ. fiir Prak. Chem., 75, 1858, 343.) LANTHANIUM. 69 C. CzuDNowIcz: 140.3 (O = 16); 876 (O = 100). Czudnowicz especially disclaims making this as an atomic weight determination and he adopts Holzmann's value. The salt analysed was the sulphate, and the method the same as that employed by Holzmann. (Erdmann's Journ. fur Prak. Chem., 80, 1860, 31.) R. HERMANN: 139.32 (O = 16); 870.75 (0 = 100). IIermann analyzed the carbonate by decomposing it over mercury by sulphuric acid, and measuring the carbon dioxide liberated. The residue was heated to redness and weighed. This experiment gave La= 580.4, the metal being assumed as bivalent. The carbonate was prepared by precipitating the sulphate with sodium bicarbonate. In three experiments the sulphate was decomposed by a-mmonium oxalate and the oxide, obtained by incinerating the oxalate, weighed. These analyses gave La = 580.7. In one experiment the chloride was analysed with argentic nitrate, giving La = 580.4. The number taken is the mean; extreme difference 2.3. In the preparation of the salts, cerium was separated as basic sulphate, La and didymium were partially separated by crystallization after which a portion of the nearly pure sulphate was precipitated by ammonia, and this precipitate digested with the mother liquor. iDidymium sulphate is by this means completely precipitated. S - 200; Cl = 443.2; C - 75. Hermann remarks that his former determination was made with impure material. {(Erdmann's Journ. fiir Prak. Chem., 82, 1861, 395.) H. ZSCHIESCHE: 135.27 (0 = 16). Determined by six experiments on the sulphate. The water was driven off at 230~, and the anhydrous salt exposed to a white heat until the weight became constant, and on being tested, showed no sulphur. The mean result was La —45.09; extreme difference, 1.15. In preparing the salt from cerite, the cerium was peroxidized with red lead and nitric acid and was precipitated as basic nitrate. The didymium was separated by partial precipitation with oxalic acid and concentration, these operations being repeated as long as the absorption lines of Di were perceptible in the spectroscope. A correction was made for the loss of weight of the crucible, and there was no dust upon its sides. S - 16. (Erdmann's Journ. fur Prak. Chem., 10/4, 1868, 174; 107, 1869, 72.) 70 ATOMIC WEIGHT DETERMINATIONS. C. ERK: 135.39 (O = 16). Determined by analysis of the sulphate by the method employed by Holzmann. The bases were separated by the methods which Hermann used. Yttrium was also eliminated. Fresenius in his Zeitschrift, 10, 509, objects to the details of the Erk's manipulation of barium sulphate. (Kopp's Jahresbericht, 1870, 319; Jena Zeitschr. fur Med. und Nat., 6, 1870, 299.) D. MENDELEJEFF: 180 (O =- 16). As La forms but one oxide, the salts of which are not, according to Marignac, isomorphous with those of the lower oxide of didynmium, Mendelejeff concludes that it belongs to the same group, but that its oxide is a binoxide, and its atomic weight 180. (Liebig's Ann., Suppl., 8, 1871, 190.) C. MARIGNAC: 138.75 (O = 16). By heating the sulphate till all acid was expelled, Marignac, in two experiments, determined La (bivalent) at 92.52 and 92.56; by precipitation with ammonia and heating at 92.24 and 92.48. The sulphate was purified by a great number of partial recrystallizations, and showed only doubtful traces of didymiumrn in the spectroscope. S = 16. (Annal. de C'him. et de Phys., (4,) 30, 1873, 67.) P. T. CLEVE: 139.15 (O =16). Determined by the conversion of lanthanium oxide into sulphate. The number is the mean; extreme difference 0.55. The oxide was purified from didymium by repeated partial precipitation from nitric acid solution with ammonia, basic didyrnium nitrate going down. The lanthanium was finally precipitated with oxalic acid. The oxide was found to be spectroscopically pure by Thalen. (Kopp's Jahresbericht, 1874, 257; Paris Bull. de la Soc. Chim., 21, 196, 246, 344.) LEAD. Regnault, Kopp and others have determined the specific heat of lead. It answers to an atomic weight of about 207. (Gmelin-Kraut, 1. c.) LEAD. 71 J. J. BERZELIUS and F. H. WOLLASTON: 207.4 (0 16); 1295 (O -- 100). Berzelius found 16.5 parts carbon di-oxide equal to 83.5 lead oxide, whence the value, if C = 75.4. [If C = 12, these figures give lead at 206.67.] Berzelius also determined the composition of the oxide at 7.15 oxygen and 92.85 lead, giving Pb = 207.52 or 1297. (Phil. Trans., 104, 1814, 20.) J. J. BERZELIUS: 207.12 (O = 16); 1294.498 (O = 100). Determined by the reduction of a known weight of oxide of lead by hydrogen and the weight of the resultant lead; mean of four nearly coincident experiments. (Poggend. Ann., 8, 1826, 184. - Longchamp is credited in some books with an atomic weight determination of lead. He made none, but only speculated on the composition of minium, taking Berzelius' determination as a basis. (Annal. de Chim. et de Phys., 34, 1827, 105.) J. J. BERZELIUS: 207.078 (O -= 16); 1294.242 (O = 100). This value is the mean of six experiments on the reduction of the oxide in a current of hydrogen. The oxide was produced by the decomposition of the nitrate by heat. As this compound reacts upon Pt, the crucible was lined out with a coating of a very basic nitrate, which prevented the lumps of neutral salt from coming in contact with the crucible. The glass in which the oxide was reduced was not attacked. [The third analysis is miscalculated. It should show an atomic weight of 1295.595. The mean is, therefore, as above, and the extreme difference 2.421.] (Poqge'nd. Ann., 19, 1830, 314.) J. J. BERZELIUS: 207.14 (O = 16); 1294.645 (O - 100). In his Lehrbuch, Berzelius selects five analyses made by the above method, three of them the same. These give the above mean, with an extreme difference of 0.704 for O - 100. (Lehrbuch, 3, 1219.) E. TURNER: 207.3 (O = 16). Determined by experiments on the conversion of metallic lead and of oxide of lead into the sulphate by solution in 72 ATOMIC WEIGHT DETERMINATIONS. nitric acid and evaporation with sulphuric acid. In three experiments, Turner found 100 lead = 146.401 sulphate; extreme difference 0.055. Berzelius had found 100 Pb — 146.419 sulphate; extreme difference 0.078. Turner takes the mean of his own and Berzelius' determinations, 146.41. In one experiment Turner found 100 oxide = 135.92 sulphate. Combination of these results gives Pb = 103.6 [or more accurately 103.65.] The oxide was prepared from subnitrate. The lead was prepared from plumbic acetate which was converted into carbonate, then into nitrate, in which form it was recrystallized, then again into carbonate, and reduced by black flux. On testing, it was found perfectly pure. Weighings reduced to vacuum. (Phil. Trans., 133, 1833, 524.) C. MARIGNAC: 207.04 (O = 16). Marignac made four experiments on plumbic chloride by Pelouze's modification of the silver titration method. IHe found Pb -- 103.57-.49-.55-.46. The number taken is the mean. The salt was titrated cold, argentic chloride being soluble in hot solutions of plumbic nitrate. The plumbic chloride was purified by recrystallization, and, after being pulverized, was dried at about 2000. According to Marignac there is no difficulty in desiccating it completely at this temperature. Ag =108; Cl - 35.5. Marignac found it impossible to convert the chloride into the sulphate completely. (Bibl. Univ., Arch. des Sciences, (2,) 1, 1858, 223.) J. DUMAS: 207.1 (O = 16). From a single experiment on the precipitation of the chloride with argentic nitrate. The chloride used was heated for twelve hours in a current of dry HC1, and the amount of water retained determined. Dumas found it impossible entirely to desiccate the salt without decomposition, drying at 2500 does not desiccate it. C1 = 35.5; Ag = 108. (Annal. de Chim. et de Phys., (3,) 55, 1859, 129.) J. S. STAS: 206.926 (O - 16). According to the mean of 10 syntheses of plumbic nitrate, 100 lead =- 159.9703 nitrate; extreme difference, 0.023. If N = 14.044, this relation gives Pb = 206.918. Stas also made six syntheses of the sulphate, which gave in mean 100 Pb = 146.4275 sulphate; extreme difference, 0.024. If S = 32.0742, this relation gives Pb = 206.934. The syntheses were made in the same way as in the determination of the LITHIUM. 73 atomic weight of silver. The drying of the nitrate could be accomplished only in vacuo and at about 155~. The weighings are for vacuum. The lead used was prepared from commercial acetate by precipitation with metallic lead, of copper, etc., conversion into sulphate, then into carbonate and reduction by potassic cyanide or black flux. (Stas, Untersuch. iiber Chem. Prop. Leipzig, 1867, 324.) LITHIUM. Regnault has determined the specific heat of lithium. It corresponds to an atomic weight of about 7. (GmelinKraut, 1. c.) The earliest determinations of this constant seem to have been made with a double salt of lithium and potassium, at all events with a very impure material. According to Arfvedson, 420.4 lithium chloride give 1322.4 argentic chloride, whence he deduces as the atomic weight the number 127.757 [or 10.22.] (Pog.qend. Ann., 8, 1826, 189.) L. N. Vauquelin found 430 lithium sulphate equivalent to 875 barium sulphate. [If S = 32; Ba = 137.08, this relation gives Li = 9.27.] Vauquelin does ndt describe the preparation of his salt. (Annal. de C(hem. et de Phys., 7, 1818, 287.) C. G. Gmelin found Li = 191.21 [or 7.65.] (P oggend. Ann., 15, 480; Gilbert's Ann., 62, 1819, 399.) Kralovanszky by two analyses of the sulphate with barium chloride got Li at from 10.096 to 10.168 (Liebig's Ann., 121, 94; Schweigger's Journ., 54, 1828, 231.) Thomson and Stromeyer also each got similar values. (Thomson's System of Chem., 7th ed., 1, 1831, 420.) R. H-IERMANN: 6.085 (O - 16); S8.03 (O - 100). Experiments were made on the carbonate by decomposing it with acid over mercury, and measuring the resultant di-oxide. For C = 75.33, these determinations give Li = 38. Several experiments were also made by analyzing the sulphate with barium chloride. For S = 201.06 and Ba = 856.88, these give Li = 38.05. Hermann precipitated lithium carbonate with ammonium carbonate, and subsequently converted it into sulphate. The chloride was prepared from the phosphate by Berzelius' method. (Poggend. Ann., 15, 1829, 480.) 74 ATOMIC WEIGHT DETERMINATIONS. J. J. BERZELIUS: 6.533 (O = 16); 40.83 (O = 100). Berzelius found that 1.874 lithium sulphate gave 3.9985 barium sulphate, and calculated this relation for S = 200.75; Ba -- 855.29. He also found 4.4545 melted carbonate 6.653 sulphate, but rejected the analysis. (Lehrbuch, 3, 1229, and Jahresbericht, 10, 1830, 96.) R. HAGEN: 6.57 (O = 16). Hagen precipitated lithium sulphate with barium chloride, and found that 0.852 dry lithium sulphate gave 1.8195 barium sulphate whence he calculates Li = 6.493. [If Ba = 137.08; S = 32; this relation gives Li = 6.57.] (Poggend. Ann., 48, 1839, 363.) J. W. MALLET: 6.95 (O = 16); 86.89 (O = 100). In two experiments a known weight of lithium chloride was precipitated by argentic nitrate, and the argentic chloride weighed. In one experiment lithium chloride was titrated with argentic nitrate by Pelouze's method. The number is the mean; the extreme difference is 0.18 for 0 = 100. Mallet takes Ag - 1349.66; C1 = 443.28. The alkalis were separated from the lithium salt by repeated treatment with ether and alcohol. The salt was examined for impurities; and was fused with a little ammonium chloride to prevent the formation of oxy-chloride. (Silliman's Amer. Journ., (2,) 22, 1856, 349.) L. TRooST: 6.5 (O = 16). Troost found this number from analysis of the carbonate which had been crystallized from water containing carbon di-oxide and dried at 200~, but does not regard it as definitive. (Annal. de Chimr. et de Phys., (3,) 51, 1857, 111.) J. W. MALLET: 7 (O=- 16). Troost having objected to Mallet's former method of determination, he redetermined it by precipitating the sulphate with a standard solution of barium chloride, the precipitating power of which had been tested on the sulphates of magnesium and sodium. This method was adopted to avoid the well-known imperfections of the sulphur determination. Compared with sodium sulphate the atomic weight of Li was found = 6.92 and 6.95. Compared with magnesium sulphate it was found = 7.07 and 7.09. LITHIUM. 75 Mg = 24; Na = 23. The sulphate was prepared from carbonate, and dried somewhat below a red heat. (Silliman's Amer. Journ., (2,) 28, 1859, 349.) K. DIEHL: 7.026 (O = 16). Determined by analysis of lithium carbonate with Bunsen's apparatus and in his laboratory. Four experiments; extreme difference, 0.024. C = 12. The salt was purified from alkalis by precipitation as carbonate, resolution in acid and reprecipitation, repeated until the sodium line was no longer visible. Diehl found that precipitation of the sulphate with barium chloride gave a nearly constant error on account of the retention of lithium in the precipitate, and led to nearly the same results as Berzelius got. (Liebig's Ann., 121, 1862, 93.) L. TROOST: 7 (O - 16). Troost found 1.309 grammes lithium chloride = 4.42 argentic chloride, and 2.75 lithium chloride = 9.3 argentic chloride. From these analyses he deduces the values 7.03 and 6.99. By decomposing the carbonate, dried at 100~, with silicic acid, he found 0.97 carbonate = 0.577 carbon di-oxide and 1.782 carbonate = 1.059 di-oxide, and infers for Li 7 and 7.02. In one experiment the carbonate was converted into sulphate. 1.217 carbonate gave 1.808 sulphate. Troost calculates Li = 7.06. [If Cl = 35.457; Ag - 107.93; C =12; S = 32; these determinations give, in the same order as above, 7.01; 6.94; 6.98; 7.02; 7.07.] The carbonate was purified by solution in water containing carbon di-oxide, and reprecipitation by boiling, the operation being repeated until the salt was spectroscopically pure. (Paris Comptes Rend., 54, 1862, 366.) J. S. STAS: 7.022 (O - 16). According to the mean of three determinations, 100 parts of silver 39.358 lithium chloride; extreme difference, 0.005. If Ag= 107.93; C1- 35.457; this ratio gives Li - 7.022. This value is confirmed by experiments on the conversion of the chloride into the nitrate, the results of which give Li = 7.018. The comparison with silver was made according to Pelouze's modification of the silver titration method. The chloride was purified from alkalis, after preliminary treatment with ether and alcohol, by pouring the dissolved salt into a boiling solution of ammonium car 76 ATOMIC WEIGHT DETERMINATIONS. bonate containing amnmonia in excess. All weighings reduced to vacuum. (Stas, Untersuch. iiber Chem. Prop., Leipzig, 1867.) MAGNESIUM. Regnault and Kopp have each determined the specific heat of this metal. It answers to an atomic weight of about 24. (Gmelin-Kraut, 1. c.) J. J. BERZELIUS: 25.3 (O = 16); 158.139 (O = 100). Determined by dissolving magnesium oxide in dilute sulphuric acid, evaporating and heating to incipient redness. 100 oxide were found = 293.985 sulphate. The sulphate was perfectly soluble in water and had therefore lost none of its acid. The oxide was purified by solution in an aqueous solution of carbon di-oxide and reprecipitated by boiling. S = 200.75. (Poggend. Ann., 8, 1826, 188; and Lehrbuch, 3, 1227.) Marchand and Scheerer recalculated this analysis for S = 200 and reached the value 157.74. They assert that the oxide may have contained alkalis and that the sulphuric acid carries off magnesium sulphate in volatilizing. (Erdmann's Journ. fiir Prak. Chem., 50, 1850, 392.) W. HENRY: F. H. WOLLASTON: 23.36 (0 = 16); 146 (O) = 100). Henry found that magnesium sulphate contained 33 per cent. magnesium oxide. If S = 200 the value follows. (Phil. Trans., 104, 1814, 21.) - LONGCHAMP: 15.35 (O = 16). In two experiments, Longchamp found that five parts of crystallized magnesium sulphate are equivalent to 4.91 barium sulphate. [If Ba = 137.08; S = 32, the number follows.] Longchamp found 53 per cent. water which is much too high. According to Marchand and Scheerer, the data for the anhydrous salt give Mg = 97.37, for S - 200; Ba = 856.8, [or 15.74.] (Annal. de Chirm. et de P/hys., 12, 1819, 265.) L. J. GAY-LussAC: 23.62 (0 = 16). 16.205 grammes crystallized sulphate were found equal to 15.345 barium sulphate, and 19.395 magnesium sulphate MAGNESIUM. 77 to 18.3455 barium sulphate. Calculating from the anhydrous salt Gay-Lussac found from these experiments respectively Mg =147.23 and Mg = 148.09 for Ba = 856.8; S -- 200. The salt was found to contain 51.43 water. [Calculated from the anhydrous salt these data give Mg - 23.55 and 23.68. Calculated from the hydrous salt (7 molecules water) the numbers give 24.14 and 24.41, if S = 32; Ba = 137.08.] Gay-Lussac remarks that the sulphate is partially decomposed at a red heat. (Annal. de Chim. et de Phys., 13, 1820, 308.) T. SCHEERER: 24.16 (O = 16); 150.97 (O = 100). Mean of six experiments on the precipitation of the sulphate with barium chloride. Extreme difference, 0.79. S - 200.75; Ba = 855.29. After weighing, the barium sulphate was treated with dilute IC1 and the chloride thus extracted allowed for. (Poggend. Ann., 69, 1846, 535.) T. SCHEERER: 24.21 (O = 16); 151.33 (O = 100). Barium sulphate formed as in the last determination was fused with soda, the barium carbonate dissolved in HC1, and reprecipitated as sulphate. In the filtrate additional magnesia was found. If the error in the former determination was the same, its corrected value would be as above. (Poggend. Ann., 70, 1847, 407.) SVANBERG and NORDENFELDT: 24.72 (O = 16); 154.504 (O = 100). Four experiments were made on the calcination of the oxalate, and three on the conversion of the magnesia so obtained into sulphate. The oxalate was dried at from 100~ to 105~ and heated to redness until the weight was constant. The oxide was dissolved in sulphuric acid, evaporated and the excess driven off by heat. The oxalate was prepared from the sulphate by precipitation with sodium carbonate and digestion with oxalic acid. The number is the mean of all experiments; extreme difference, 0.514. S = 200.75; C = 75.12; H = 12.48. (Erdmann's Journ. fiir Prak. Chem., 45, 1848, 473.) According to Marchand and Scheerer, the data give Mg 154.27 for S - 200; H = 12.5; C - 75. MARCHAND and SCHEERER: 24.03 (O = 16); 150.19 (O - 100). Eleven experiments were made in calcining massive magnesium carbonate from Frankenstein, and weighing the 78 ATOMIC WEIGHT DETERMINATIONS. caustic magnesia formed. The carbonate was dried at 3000, and the carbon di-oxide, which passes off above 2300, was caught by caustic baryta solution and determined. The traces of carbon di-oxide not expelled by a yellow heat were set free by solution in chlorhydric acid and also determined as barium carbonate. The silicic acid, etc., were also determined. The mean in air is 150.34; in vacuo as above. Extreme difference, 0.57. C = 75. Eleven other experiments were made with comparatively impure material and less precaution, tending to confirm the above. (Erdmann's Journ. fiir Prak. Chem., 50, 1850, 409.) T. SCHEEERE: 24 (O = 16); 150 (O = 100). By separating the neutral sulphates of magnesium and calcium by means of alcohol, Scheerer found that the magnesites used by Marchand and himself contained from onefourth to one-half per cent. calcium oxide. This correction would make their determination almost exactly 250 or 24. (Liebig's Ann., 110, 1858, 236.) V. A. JACQUELIN: 24.408 (O = 16); 152.55 (O - 100). Anhydrous, neutral magnesium sulphate, obtained by solution of the oxide in sulphuric acid and heating to redness, gave 33.56 per cent. pure oxide. The method adopted is not described. This oxide by treatment with sulphuric acid gave the original amount of sulphate. If S = 200, the number follows. (Annal. de Chim. et de Phys., (3,) 32, 1851, 195.) A. MACDONNELL: 23.9 (O =16). Determined from analyses of anhydrous and of crystaltized magnesium sulphate. (Brit. Assoc. Rep., 1852, part 2, 36; and Kopp's Jahresbericht, 5, 364.) J. F. BAHR: 2.77 (O = 16); 154.842 (O = 100). A known weight of purified magnesium oxide was dissolved in sulphuric acid, evaporated and heated to redness till the weight was constant. The number is the mean of three experiments; extreme difference, 0.515. The oxide was obtained from meteoric olivin. After removal of the heavy metals, the solution was evaporated to dryness with soda, washed and heated to redness. The oxide so obtained was dissolved in acetic acid, oxalic acid was added, the MANGANESE. 79 solution evaporated nearly to dryness, and the oxalate thoroughly washed. Bahr says that the presence of alkalis could not be suspected. S = 200. (Erdmann's Journ. fiir Prak. Chem., 56,1852, 310; (Efversigt af Akad. Foerh., 1851, 303.) Scheerer says that oxide so prepared retains carbonic acid, that sulphate is carried off in heating the sulphate to redness, and that the presence of alkalis is to be suspected. (Erdmann's Journ. fiir Prak. Chem., 56, 1852, 489.) J. DUMAS: 24.6 (O- =16). Dumas made eleven experiments on the titration of magnesium chloride with argentic nitrate. He found great difficulty in preparing pure chloride, and does not feel confident of his results. The number is the mean; extreme difference, 0.28. Ag - 108; Cl - 35.5. The chloride was prepared from various salts, but was in all cases finally heated in an atmosphere of HC1. Dumas points out, however, that this process does not remove oxide if present. (Annal. de Chim. et de Phys., (3,) 55, 1859, 129.) MANGANESE. Regnault has determined the specific heat of manganese. It corresponds to an atomic weight of about 55. (Gmelinkraut, 1. c.) J. J. BERZELIUS: 56.93 (O = 16); 355.787 (0= 100). By dissolving manganese in nitric acid, evaporating and heating to a low red, Berzelius found 100 Mn = 142.16 oxide. It was not known at the time that the oxide might be partially reduced by this process. (Poggend. Ann., 8, 1826, 185; and Jahresbericht, 9, 136.) J. A. ARFVEDSON: 56.25 (0=16); 351.56 (0= 100). From 1.508 chloride Arfvedson obtained 3.408 argentic chloride. If Ag = 1351.607; Cl = 221.325; the number follows. (Berzelius' Jahresbericht, 9, 1829, 136; Afhandl. i. Fysik., 6, 236.) 80 ATOMIC WEIGHT DETERMINATIONS. E. TURNER: 54.9 (O -=16). Turner analyzed the carbonate in an apparatus similar to Bunsen's. He found 34.72 per cent. carbon di-oxide and 8.427 water. For C = 6, he calculates Mn = 28.024. By dissolving the protoxide in sulphuric acid, evaporating and heating to redness, he found 9 oxide = 19.01 sulphate. If S = 16, this gives Mn = 27.96. A second experiment gave 27.93. From 12.47 Mn chloride he obtained 28.42 argentic chloride. [If C1 = 35.5, Ag = 108; this gives Mn = 54.9.] The carbonate was obtained by precipitation with potassium carbonate. The protoxide was obtained by reduction of higher oxides in hydrogen. The chloride was melted in a current of HCL gas. (Edinb. Trans., 11, 1831, 143.) J. J. BERZELIUS: 55.34 (O — 16); 345.9 (O =100). Berzelius repeated Turner's experiments, taking larger quantities. From the chloride he got from 345.84 to.96; from the sulphate from 346.03 to.29. Ag = 1351.607; C1 = 221.325; S = 201.165. (Berzelius' Jahresbericht, 9, 1830, 136.) J. J. BERZELIUS: 55.14 (O = 16); 344.684 (O = 100). In his Lehrbuch he apparently takes the analyses of the chloride above cited, recalculated for Cl = 221.64; Ag = 1349.66. (Lehrbuch, 3, 1224.) R. BRANDES: 57.06 (O = 16); 356.602 (O- = 100). Determined by analysis of crystallized chloride. The chlorine was determined by precipitation with silver. The Mn was precipitated as carbonate, and converted into oxide by heat. The water was determined by difference, and the composition of the oxide was assumed to be as given by Berzelius, (!) whose values for Ag and Cl were also taken. (Poggend. Ann., 22, 1831, 256.) K. VON HAUER: 54.98 (O = 16); 343.632 (O = 100). Determined by nine experiments on the reduction of the sulphate to sulphide by heating the salt in a current of hydrogen sulphide. The reduction was performed in a porcelain tube enclosed in a charcoal fire. Number, mean; extreme difference, 0.34, for 0 = 16. The sulphate was prepared from a pyrolusite containing only silica, iron, and barium. It was reduced to protoxide, dissolved in sulphuric acid, oxidized with nitric acid, precipitated with oxalic MERCURY. 81 acid, converted into red oxide, dissolved in chlorhydric acid and alcohol, precipitated with ammonium carbonate, dissolved in sulphuric acid, repeatedly heated to redness and recrystallized, and was dried at 3000. Accurate experiments on the reduction of the red oxide proved impracticable on account of the hydroscopicity of the compound. Two experiments on the oxidation of the protoxide, undertaken as a check on the other method, gave 27.486 and 27.527 for O = 8; S = 16. (Erdmann's Journ. fur Prak. Chem., 72, 1857, 361; Sitz.-Bericht der k. k. Akad., 1857.) J. DUMAS: 54.96 (O = 16). Determined by the decomposition of the chloride with argentic nitrate. The number is the mean of five experiments; extreme difference, 0.1 for O = 16. Cl 35.5; Ag-= 108. Dumas had previously made experiments on the reduction of the hyperoxide to protoxide by hydrogen. These gave the atomic weight at from 25.99 to 26.09 for O = 8. Dumas believes that a part of the oxide was reduced to metal. The peroxide was prepared from nitrate of the protoxide. (Annal. de Chim. et de Phys., (3,) 55, 1859, 150.) - RAWACK: 54.02 (O = 16). Determined, in Schneider's laboratory, by reducing a known weight of red oxide to protoxide in a current of dry hydrogen, and weighing the water formed. The number is derived from the mean of six selected experiments. The extreme difference is 0.22 for O = 16. (Poggend. Ann., 107, 1859, 607.) R. SCHNEIDER: 54.038 (O = 16). The mean result of four analyses of the oxalate by the ordinary method of organic analysis. Extreme difference, 0.04 for O - 16. C = 12. The oxalate was prepared from chemically pure sulphate by precipitation with sodium carbonate, digestion with oxalic acid, and drying over sulphuric acid. (Poggend. Ann., 107, 1859, 613.) MERCURY. The specific heat of mercury in the solid state, as observed by Regnault, and the vapor density, as determined by Dumas, correspond to an atomic weight of slightly above 200. (Gmelin-Kraut, 1. c.; L. Meyer, 1. c.) 6 82 ATOMIC WEIGHT DETERMINATIONS. FOURCROY AND THENARD, DAVY, WOLLASTON: 200.8 ( = 16); 1255 (O = 100). Fourcroy and Thenard found 8 O = 100 Hg. Davy found 30 O =380 Hg, giving Hg - 1266. The latter also found 134 C1 -= 380 Iig, which for C1 - 441, gives Hg — 1254. (Phil. Trans., 104, 1814, 21.) N. G. SEFSTROEM: 202.53 (O = 16); 1265.822 (O- = 100). Determined by three analyses of the oxide according to which 100 IHg = 7.89, 7.9, and 7.97 0. (Berzelius' Lehrbuch, 3, 1215.) E. TURNER: 200.72 (O = 16). Turner made a number of determinations of this atomic weight but regarded the value he adopted, 202, only as an approximation. From the oxide, prepared from nitrate, he got 200.77 and 199.97. The compound was decomposed by heat, and the products carried over silver and gold in a narrow tube. Four experiments were made on mercuric chloride which was decomposed by pure calcic oxide, and the C1 precipitated with argentic nitrate. [These analyses recalculated for the Stas' atomic weights of Ag and Cl give 202.079, 201.701, 201.815.] Turner also made two experiments on the reduction of the chloride with stannous chloride, the I-g being collected, dried and weighed. [These experiments recalculated give 199.423 and 199.289.] The mercuric chloride was purified by recrystallization. Weighings reduced to vacuum. (Phil. Trans., 123, 1833, 535.) ERDMANN AND MARCHAND: 200.14 (O = 16); 1250.6 (O = 100). Determined from the mean of four experiments on the reduction of the oxide in a current of carbon di-oxide. Copper, carbon (from sugar) oxide, and carbon, were introduced in successive layers in a combustion tube. Dry carbon di-oxide was passed through and the mercuric oxide heated. The metal was collected in a receiver to which a tube filled with gold foil was appended. The metal was perfectly clean. Moisture was removed by a stream of dry air after distillation. The oxide was purified by heating it to incipient decomposition the metallic fumes being removed MOLYBDENUM. 83 by a current of dry air. It was tested before being analysed. The extreme difference in the results was 0.8 for O = 100. All weighings in vacuo. (Erdmann's Journ. fur Prak. Chem., 81, 1844, 392.) E. MILLON: 199.94 (O = 16); 1249.63 (O = 100). Millon made two experiments by heating mercuric chloride with calcic oxide in a current of hydrogen and condensing the metal. The experiments gave 73.87 and 73.82 per cent. mercury. If Cl - 442.64, the value follows. The chloride was dissolved in ether and sublimed. It was perfectly soluble in ether and alcohol, and was well crystallized. (Paris Comptes Bend., 20, 1845, 1291.) L. SVANBERG: 200 (O -- 16); 1250 (O = 100). Svanberg made three experiments by the same method employed by Millon. The mean result was 1248.47; extreme difference, 0.94; but Svanberg shows that there was probably loss, and that the larger the quantity of chloride employed the higher the result. He regards Erdmann and Marchand's result as most probable, but in need of confirmation. Cl = 443.28. (Erdmann's Journ. fiir Prak. Chem., 45, 1843, 468; Kongl. Vet. Akad. Handl., 1845, 135.) MOLYBDENUM. Regnault determined the specific heat of molybdenum. It answers to an atomic weight of about 96. (Gmelin-Kraut, 1. c.) J. J. BERZELIUS: 95.36 (O = 16); 596.1 (O = 100). One hundred parts of anhydrous plumbic nitrate, dissolved and precipitated with neutral ammonium molybdate, gave 110.68 parts plumbic molybdate. If Pb = 1294.645, N = 87.53, the value follows. Berzelius expresses himself dissatisfied with the accuracy of the determination. (Poggend. Ann., 8, 1826, 23; and Lehrbuch, 3, 1208.) SVANBERG AND STRUVE: 92.13 (O- 16); 575.829 (O =0 100). After trying various methods without getting accordant results, these chemists made ten experiments on the sul 84 ATOMIC WEIGHT DETERMINATIONS. phide by roasting it first in a current of moist, and then of dry air. Three experiments were excluded as imperfect. The remainder gave a mean of 89.7523 molybdic acid from 100 sulphide; extreme difference, 0.22. The value follows for S = 200. Objections have been made (Liebig's Ann., 6S, 211) that the difference in weight between the acid and the sulphate is too small for the purpose of the determination, and that the different analyses give very different atomic weights. The sulphide was prepared by melting together molybdic acid, sulphur, and caustic potash, and leaching the product with water and chlorhydric acid. The sulphide was dried in a current of hydrogen. The molybdic acid was dissolved in ammonia to prove the absence of sulphide. (Erdmrann's Journ. fiir Prak. Chem., 44, 1848, 315.) N. J. BERLIN: 91.96 (O = 16); 574.75 (O = 100). Determined by four analyses of the double mrnono-sesquimolybdate of ammonium by heating gently with nitric acid in a platinum crucible until only mnolybdic acid was left. Extreme difference, 3.32 for O = 100; N = 175; H - 12.5. The preparation of the salt is not given. (:Erdmann's Journ. filr Prak. Chem., 49, 1850, 446.) J. DUMAS: 96 (O = 16). Dumas made five experiments on the reduction of molybdic acid (prepared from the natural sulphide) by means of hydrogen. The reduction was begun at a low temperature in a glass tube, and completed in an unglazed porcelain tube in a reverberatory furnace, where it was kept till several hours heating produced no further alteration in weight. The molybdenum did not assume a metallic appearance.. The number is the mean; extreme difference, 0.8 for O016. (Annal. de Chim. et de Phys., (3,) 65, 1859, 142.) M. DELAFONTAINE: 92 (O = 16); 575 (O = 100). This chemist made many experiments in various ways without being able to reach constant results, and only remarks that his experiments indicate Svanberg and Struve's value as the best. (.Erdmann's Journ. fur Prak. Chem., 95, 1865, 137; Bibl. Univ., Arch. des Sciences, 23, 1865.) -I. DEBRAY: 95.94 (O = 16). Debray made three experiments on the reduction of molybdic acid. The acid was first converted into the red MOLYBDENUM. 85 oxide in platinum, and at a low temperature, and the small portion of the acid volatilized during this operation was caught and determined. The reduction was completed in a porcelain tube at a white heat. Debray gives his results at 48.03; 48.04; and 47.84. [The analytical data, recalculated, give 95.30; 95.55; 95.73; perhaps on account of misprints. Reduction to vacuum would still further reduce the numbers.] The acid was purified by sublimation in platinum, conversion into ammonium salt, and regeneration by heat. In two experiments ammoniacal solution of molybdic acid was evaporated in the dark with excess of argentic nitrate, the argentic molybdate dissolved out and the excess of silver determined. Debray found 5.510 acid = 7.657 silver, and 7.236 acid = 10.847 silver. Hence he calculates M = 48 and 47.98. [A little calculation shows that the first data are misprinted. They should read 5.11 acid = 7.657 silver. The corrected data give for Ag = — 107.93; M = 96.06 and 95.99. The mean of the recalculated analyses is 95.73.] (Paris Comptes Rend., 66, 1868, 732.) L. MEYER: 96.10 (O = 16). Calculated from three analyses of the dichloride, two analyses of the tetrachloride, and two analyses of the pentachloride, made by Leichte and Kempe in Meyer's laboratory. The dichloride was analyzed by heating in a current of hydrogen sulphide, and subsequently in a current of hydrogen. Molybdenum disulphide is the residue. The HCl formed was caught in ammonium hydrate and precipitated by argentic nitrate, after the hydrogen sulphide had been driven off by boiling in a flask provided with a condensing drip-tube. The tetra and pentachloride were decomposed with nitric acid, excess of ammonium hydrate was added, and molybdenum trisulphide precipitated with ammonium sulphide. A weighed portion of the dry precipitate was converted into disulphide by heating in a current of hydrogen. The chlorine of the higher chlorides was determined in the filtrate after precipitation of the trisulphide. By comparing the amount of chloride analyzed with the amount of argentic chloride obtained, Meyer finds in mean M = 95.92; extreme difference, 1.87 for O - 15.96. By comparing the amount of disulphide with that of argentic chloride, M - 95.75; extreme difference, 1.35. By comparing the amount of chloride analyzed with the amount of disulphide obtained for one analysis of tetrachloride and two analyses of pentachloride, he gets M = 95.94; extreme difference, 2.15. The general mean is M 95.86; extreme 86 ATOMIC WEIGHT DETERMINATIONS. difference, 2.15. Ag= 107.66; S =31.98; Cl 35.37; O - 15.96. The specific gravities of the chlorides not having been determined, the weighings are not reduced to vacuum. The pentachloride was prepared fiom M by heating it in a current of Cl entirely free from air. The metal had been freed from oxide by heating in an atmosphere of HCI. By moderate heating of the pentachloride in dry H, and by distilling pentachloride over the product in dry carbon di-oxide, the trichloride is obtained. The trichloride heated in carbon di-oxide is decomposed into tetrachloride and di-chloride, which latter must be purified with warm dilute nitric acid. (Liebig's Ann., 169, 1874, 360, 344.) NICKEL. Regnault has determined the specific heat of nickel. It corresponds to an atomic weight of about 59. (GmelinKraut, 1. c.) E. ROTHOFF: 59.09 (O = 16); 369.333 (O = 100). Rothoff converted 188 parts of oxide into chloride, a neutral solution of which gave 718.2 parts argentic chloride. If Cl = 221.64, Ag = 1349.66, the value follows. (Berzelius' Lehrbuch, 3, 1221.) P. BERTHIER. Lassaigne having announced the atomic weight of nickel at 500, (Schweigger's Jahrbuch, 9, 108,) Berthier re-examined the subject and found Rothoff's number confirmed. (Berzelius' Jahresbericht, 5, 1825, 148; Annal. de Chim. et de Phys., 25, 1824, 148.) ERDMANN AND MARCHAND: 58.2 (0 = 16); 365.9 (0 = 100). Determined " with all precaution" by the reduction of the oxide with hydrogen. The results varied from 29.1 to 29.3, but Erdmann has reason to believe the smaller number the more accurate. (Erdmann's Journ. fiir Prak. Chem., 55, 1852, 202.) NICKEL. 87 IH. SAINTE-CLAIRE DEVILLE: 100 parts fused nickel, containing three-tenths per cent. silicon and one-tenth per cent. copper, gave 262 parts anhydrous, yellow nickel sulphate, " corresponding to the atomic weight as given by Berzelius." (Annal. de Chirm. et de Phys., (3,) 46, 1856, 182.) R. SCHNEIDER: 58.05 (O = 16); 362.8 (O =100). Determined from four analyses of the oxalate. The carbon determinations were made by the ordinary method of organic analysis, because some hydrocarbon forms when the salt is decomposed by heat alone. The metal was determined by heating a known weight of the salt first in air and then in a current of oxygen, and subsequent reduction by hydrogen. In the preparation of the salt the usual precipitate with ammonium sulphide was washed with dilute chlorhydric acid, and the cobalt separated with barium carbonate and chlorine. From the nickel salt obtained the oxalate was precipitated with oxalic acid. The number is the mean of four analyses; extreme difference, 0.082 for O _ 8. (Poggend. Ann. 101, 1857, 396.) C. MARIGNAC: 59 (O = 16). Marignac made two analyses of the sulphate by decomposing the salt by heat. The decomposition is perfect. To avoid errors arising from possible reduction of a portion of the oxide, it was moistened with nitric acid, and recalcined at a moderate temperature. The results obtained were Ni = 29.2 and 29.5. The sulphate was purified by recrystallization. He also made experiments on the chloride by titration with argentic nitrate, according to Pelouze's modification of Gay-Lussac's method. Three such analyses gave from 29.4 to 29.5. In one experiment he also evaporated the nickel nitrate, after filtering off the argentic chloride, and converted it into oxide by heat. This experiment gave Ni = 29.64. The chloride, whether it be distilled or calcined with ammonium chloride, is apt to leave an insoluble residue the weight of which must be deducted. S -- 16; Ag = 108; C1 = 35.5. (Bibl. Univ. Arch. des Sciences, (2,) 1, 1858, 375.) J. DUMAS: 59.028 (O - 16). The number is the mean result of five experiments on the titration of the chloride with argentic nitrate; ex 88 ATOMIC WEIGHT DETERMINATIONS. treme difference 0.08. Ag - 108; C1l =35.5. In three cases the nickel chloride was prepared by dissolving fused nickel in aquia regia, repeated evaporation to dryness with HC1, and heating for from twelve to twenty-four hours in a current of HC1 gas. In two cases it was produced by passing a current of chlorine over spongy nickel. The chloride analyzed was crystalline and volatile without residue. (Annal. de Chim. et de Phys., (3,) 55, 1859, 149.) R. SCHNEIDER: 58.058 (O = 16). In consequence of Marignac's criticism (that as nickel oxalate is insoluble it cannot be purified by recrystallization) Schneider repeated his former determination, making special tests for oxalic acid, sodium, and chlorine, with the above result. (Poggend. Ann., 107, 1859, 616.) W. J. RUSSELL: 58.738 (O 16 ). Determined from the mean of thirteen experiments on the reduction of the oxide in hydrogen. Extreme difference, 0.12 for O -= 16. The oxide was prepared from three specimens of commercial nickel, which were first converted into pure oxalate and then into nitrate. The oxide was obtained by decomposing the nitrate by a very strong heat. (Journ. Chem. Soc., (2,) 1, 1863, 61.) Schneider remarks that a portion of the oxide analyzed may have been reduced during the process of decomposing the nitrate. (Poggend. Ann., 130, 1867, 310.) Marignac points out the same danger. (Bibl. Univ., Arch. des Sciences,.(2,) 1, 374.) E. VON SOMMARUGA: 58.026 (O =16). Determined from the amount of barium sulphate obtained by precipitating the double sulphate of nickel and potassium with barium chloride. The number is the mean of six experiments; extreme difference, 0.168 for O = 8, S = 16; Ba [no doubt] = 68.5; K = 39.2. The salt was prepared by solution of commercial nickel in sulphuric and nitric acid, adding potassic sulphate to the solution, and repeatedly recrystallizing the double sulphate. (Erdmann's Journ. fur Prak. Chem., 100, 1867, 115; Sitz.-Ber. der k. k. Akad., 1866.) C. WINKLER: 59.05 (O = 16). Determined by the amount of gold precipitated from a solution of neutral crystallized potassium chloro-aurate by NIOBIUM. 89 a known weight of nickel. The number is the mean of four experiments; extreme difference, 0.186 for 0- =16, Au = 196. The nickel was prepared as follows: commercial nickel carbonate was dissolved in chlorhydric acid, cobalt was repeatedly precipitated with sodium hypochlorite, copper, etc., were removed with hydrogen sulphide, the nickel was precipitated with sodium carbonate, the pre-' cipitate dissolved in chlorhydric acid, the chloride sublimed and reduced in a current of hydrogen. (Fresenius' Zeitsch., 6, 1867, 22.) W. J. RUSSELL: 58.76 (O = 16). Determined by the amount of hydrogen set free by solution of nickel in chlorhydric acid. The nickel was that obtained in Russell's former determination of the atomic weight of nickel. (Chem. News, 20, 1869, 20.) R. H. LEE: 58.01 (O = 16). Determined by analyses of nickel cyanide salts. They were decomposed in a platinum crucible by heat from above. The carbon separated out was burned off first in air and then in oxygen. The metallic oxide was reduced in a current of hydrogen. The mean of six experiments on the strychnine salt gave Ni = 58.04. The mean of six experiments on the brucine salt gave Ni = 57.98. The salts were purified by recrystallization. (Berlin. Bericht der Chem. Ges., 4, 1871, 790.) NIOBIUM. The vapor density of the chloride and of the oxychloride, as determined by Deville and Troost, places the atomic weight at about 94. (Paris Comptes Rend., 56, 1863, 891.) H. RosE: 122 (O- - 16). Rose deduced the atomic weight of niobium from analyses of what he supposed to be the tetrachloride, determining the niobium as niobic acid, and the chlorine as argentic chloride. The results, which varied greatly, indicated the value 97.64. [Marignac having proved that the salt is a pentachloride, this number becomes 122.] Marignac showed 90 ATOMIC WEIGHT DETERMINATIONS. that Rose dealt with a compound containing a large amount of the corresponding tantalium chloride. (Poggend. Ann., 104, 1858, 439.) ROSE; RAMMELSBERG: 94 (O = 16). Rose analysed the oxychloride, but did not recognize it as an oxychloride. Rammelsberg calculated the atomic weight from Rose's figures and found that the highest chlorine contents corresponds to an atomic weight of 94. Rose's salt must have been nearly pure as there is no corresponding tantalium compound. (Poggend. Ann., 136, 1869, 353.) R. HERMANN: 104.8 (O = 16). Hermann deduces this value from analyses of a number of chlorides and sodium salts. The formulas which he gives these compounds are complicated, unlikely, and unsupported by evidence. Marignac has shown that Hermann's salts contained tantalium. (Erdmann's Journ. fiir Prak. Chem., 68, 1856, 73.) C. W. BLOMSTRAND: 95 (O = 16). Blomstrand made three determinations of the chlorine contents of the pentachloride, getting 64.712 per cent., extreme difference, 0.32. IHe also made eleven determinations of the niobium in the same compound, weighing it as niobic acid. 100 chloride gave in mean 49.794 acid. The atomic weight calculated from the chlorine contents is 96.67; from the niobic acid, 96.16. Blomstrand also made experiments on sodium niobate which led him to the conclusion that the most probable number is 95. (GmelinKraut, 2, part 2, 73; Acta Univ. Lund., 1864.) C. MARIGNAC: 94 (O- 16). Determined from a number of analyses of potassium fluoniobate containing two atoms of potassium. The compound was decomposed by sulphuric acid with which it was evaporated to dryness. The residue was leached with water, the filtrate evaporated and the potassic sulphate melted and weighed. The sulphuric acid remaining with the niobic acid was driven off by heat and the acid weighed. The salt being readily soluble and crystallizing well, can easily be purified from all substances except titanium which Marignac knows no way of separating or determining. NITROGEN. 91 The larger the amount of titanium present, the lower will the atomic weight be; Marignac therefore takes the highest value. (Liebig's Ann., S. 4, 334, 288, 338; Bibl. Univ., Arch. des Sciences, 23, 1865, 25, 1866.) NITROGEN. Regnault has determined the specific gravity of nitrogen. It indicates an atomic weight slightly above 14. (GmelinKraut, 1. c.) BIoT and ARAGO; WOLLASTON: 14.03 (O = 16); 87.7 (O- = 100). Biot and Arago found the specific gravities of N and It 0.96913 and 0.07321. If H -- 13.27 the value follows. [This very accurate value is of course the result of two compensatingzerrors.] (Phil. Trans., 104, 1814, 20.) J. J. BERZELIUS; 14.163 (O = 16); 88.518 (O =100). Calculated from the specific gravity as determined by Berzelius and Dulong, compared with that of oxygen. By decomposing the nitrate of lead by heat, Berzelius also found IN = 88.61 for Pb = 1294.498. (Poqgend. Ann., 8, 1826, 14.) E. TURNER: 14.15 (O = 16). Determined by experiments on the nitrates of lead, silver, and bariujn, which were precipitated with sulphuric and hydrochloric acids, and gave respectively N 14.201; 14.09; 14.17; if Pb = 103.6; Ba=68.7; C1 = 35.42; S = 16.085; the weighings being reduced to vacuum. The salts were purified by recrystallization. Turner recommends more direct methods. (Phil. Trans., 123, 1833, 537.) T. THOMSON: 14 (O = 16). From the hypothesis that air is a compound containing four parts of N and one part oxygen, and from the average of various selected determinations of the specific gravity of oxygen, Thomson concludes the specific gravity of oxygen is 1.1111, and that of N 0.9722. These numbers stand 92 ATOMIC WEIGHT DETERMINATIONS. to one another as 16 to 14. (Erdmann's Journ. fiir Prak. Chem., 8, 1836, 375; Records of General Science, by R. D. Thomson, 1836, 179.) F. PENNY: 14.018 (O = 16). From the mean of three series of experiments (vide Penny's determination of potassium) it follows that 100 potassic chloride = 135.636 potassic nitrate. Penny found the molecular weight of KC1 = 74.527; hence the difference between a chloride and a nitrate is 26.560. Similar experiments were made on the sodium salts. In four experiments 100 sodium chlorate were found = 54.930 chloride; extreme difference, 0.02. In three experiments, 100 sodium chlorate were found - 79.882 sodium nitrate; extreme difference, 0.015. In six experiments 100 sodium nitrate were found — 68.771 chloride; extreme difference, 0.013. In seven experiments 100 chloride were found = —145.416 sodium nitrate; extreme difference, 0.016. These data give sodium chloride = 58.5, and the nitrate = 85.068, or the difference between a chloride and a nitrate - 26.568. Penny found Cl = 35.454. If NO3-Cl = 26.564, N= 14.018. Weighings for vacuum. (Phil. Trans., 19, 1839, 25.) L. SVANBERG: 13.91 (O = 16). Determined by four experiments on the decomposition of plumbic nitrate by heat which gave a mean of 67.4016 per cent. oxide; extreme difference, 0.0087. [If Pb = 206.926 (Stas) the value follows.] (Berzelius' Jahresbericht, 22, 1842, 38.) C. MARIGNAC: 14.02 (O = 16); 87.625 (O = 100). Marignac made five experiments by dissolving a known weight of silver in nitric acid and melting and weighing the nitrate formed. The silver carried out of the retort by the vapors was precipitated and determined. The mean result was that 100 silver — 157.430 nitrate; extreme difference, 0.046; or, if Ag = 1349.01, N _87.535. Six experiments were made by the decomposition of a known weight of argentic nitrate with a known weight of potassic chloride by Pelouze's method. Mean, 100 KCl = 227.986 argentic nitrate; extreme difference, 0.18. This gives N - 87.685 if K = 488.94 and Cl - 443.2. Seven experiments by the same method showed that 100 silver dissolved in nitric acid = 49.522 ammonium chloride; extreme differ NITROGEN. 93 ence, 0.063; Hence N = 87.655. The weighings are reduced to vacuum. (Berzelius' Jahresbericht, 24, 1842, 44; Bibl. Univ. de Geneve, 46, 1842, 363.) T. ANDERSON: 13.95 (O = 16); 87.2X)4 (O = 100). Determined by four experiments on the decomposition of plumbic nitrate by heat at a sufficiently low temperature to permit of complete decomposition. The number is the mean; extreme difference, 0.198 for O -- 100. Pb - 1294.5. (Annal. de Chimrn. et de Phys., (3,) 9, 1843, 254.) J. PELOUZE: 14.014 (O - 16); 87.59 (O = 100). A known weight of argentic nitrate was brought in contact with a known and slightly excessive weight of ammonium chloride and the excess titrated with silver solution. One experiment gave N= 175.58; a second gave N= 174.78. Ag = 1349.01; C1 = 443.2. The ammonium chloride was purified by sublimation and recrystallization. (Paris C~omptes Rendl., 20, 1845, 1047.) P. EINBRODT: 14 (O = 16); 87.5 (O = 100). Experiments on the decomposition of plumbic nitrate by heat gave N = 87.5 plus a vanishing quantity if Pb = 1294.2239. (Leibig's Ann., 70, 1849, 286.) J. DUMAS: 14 (O = 16). Determined by experiments on the combustion of ammonia and cyanogen. Particulars not given. C = 6; H = 1. (Annal. de Chim. et de Phys., (3,) 55, 1859, 134.) J. S, STAS: 14.044 (Q = 16). Stas made seven determinations of the relation between silver and its nitrate by dissolving pure silver in nitric acid, evaporating to dryness and keeping the salt melted until there was no further loss of weight. In two of these experiments the salt was melted in vanuo. The mean result was that 100 Ag = 157.472 nitrate; whence N = 14.040. Later Stas made two more experiments by the same method with all possible precautions to secure accuracy. These gave 100 Ag = 157.484 nitrate and N = 14.042. By the conversion of the chlorides of potassium, sodium, lithium and silver into nitrates, Stas found the difference between a chloride and a nitrate 26.5882. This gives N = 14.045. The weigh '94 ATOMIC WEIGHT DETERMINATIONS. ings are reduced to vacuum. C1 - 35.457; Ag = 107.93. (Stas, Unters. iiber Chem. Prop. Leipzig, 1867.) OSMIUM. Regnault has determined the specific heat of osmium. It corresponds to an atomic weight of about 199. (GmelinKraut, 1. c.) J. J. BERZELIUS: 199.04 (O = 16). Berzelius analyzed potassium chloro-osmate by reduction in a current of hydrogen and solution of the potassium chloride from the residue. 1.3165 grammes of the double salt lost 0.3805 in reduction and the residue was composed of 0.401 potassium chloride and 0.535 osmium. The atomic weight may be calculated either from the chlorine lost or from the relation of the chloride to the metal in the residue. Berzelius preferred the latter as more probably accurate. [If K1 -= 39.137; Cl = 35.457 (Stas;) this relation gives 199.04.] According to W. M. Watts, (Chem. News, 19, 302) the loss of chlorine gives for Stas's values Os = 199.42. Hyperosmic acid was separated firom iridium compounds by distilling at a gentle heat. The first portion is perfectly pure. The metal was precipitated from chlorhydric acid solution of hyperosmic acid by mercury and subsequently purified by heating in a current of hydrogen. Potassium chloro-osmate was formed by heating comminuted metal and KC1 in a current of chlorine. (Poggend. Ann., 13, 1828, 530; Kongl. Vet. Acad. Handl., 1828.) E. FREMY: 199.65 (O = 16); 1247.8 (O = 100). Pure osmium was burned in a current of oxygen and the fumes led over potassic hydrate, by which they are absorbed. An additional potash tube did not increase in weight. Corks were avoided. Number of experiments not given. (Erdmann's Journ. fiir Prak. Chem., 33, 1844, 409; Journ. de Pharm. et Chim., 1844, 241.) DEVILLE and DEBRAY: 198 (O = 16). These chemists determined the vapor density of hyperosmic acid by Dumas' method, finding it 8.89 at 246~, PALLADIUM. 95 and 8.87 at 286~. They hence consider it probable that the atomic weight of osmium is the same as that of platinum. The acid was very-pure and was prepared by the combustion of metallic osmium in oxygen. (Paris, Comptes BRed., 44, 1857, 1101.) OXYGEN. The atomic weight of oxygen is assumed at 16 for the reasons stated under hydrogen, q. v. If hydrogen is taken as unity, O = 15.96. PALLADIUM. Regnault determined the specific heat of palladium. It corresponds to an atomic weight of about 106. (GmnelinKraut, 1. c.) J. J. BERZELIUS; 106.51 (O - 16). In his earliest determinations of this constant, Berzelius saturated the metal with sulphur, getting about 711 for S = 201.165; and decomposed the chloride with mercury, getting 704. [711 appears to be a misprint for 714.618 the number given with corresponding data at Poggend., 8, 180.] In this investigation a known weight of potassium chloropalladate was reduced in a current of hydrogen, the weight of the residue determined, the potassium chloride leached from the residue and the metallic palladium weighed. The double salt was strongly heated, but not to fusion, in a current of dry air before weighing. It being impossible to desiccate this and the similar platinum-metal salts completely without decomposition, the atomic weight was calculated from the relation between the metal and the KC1. Berzelius found 0.575 Pd = 0.809 KC1, and 0.851 Pd = 1.192 KC1. [If KC1 = 74.594 (Stas) the former gives Pd - 106.036, the latter 106.509.] Berzelius had reason to consider the latter analysis the more accurate. (Poggend. Ann., 18, 1828, 454; Kongl. Vet. Acad. Handl., 1828.) 96 ATOMIC WEIGHT DETERMINATIONS. PHOSPHORUS. The specific heat of this element, as well as the density of phosphorus and its numerous volatile compounds in the gaseous state, corresponds to an atomic weight slightly above 31. (Gmelin-Kraut, 1. c.) V. ROSE; F. H. WOLLASTON: 35.1 (O- = 16). Wollaston adopted the analysis of Rose, who found that phosphoric anhydride contained 53.28 per cent. oxygen and 46.72 per cent. phosphorus. [This relation gives the above value.] (Phil. Trans., 104, 1814, 20.) J. J. BERZELIUS: 31.325 (O = 16). Berzelius made experiments on the reduction of auric chloride and of argentic sulphate by phosphorus. His results were 0.8115 P - 13.98 Ag; 0.829 P = 8.714 Au; 0.754 P = 7.93 Au. [The first of these analyses is misprinted in the original memoir (Gilbert's Ann., 53, 433).] In the Lehrbuch it is miscalculated as Ruecker has shown. Berzelius preferred deducing the atomic weight of P from that of silver, because the atomic weight of the latter was more accurately known than that of gQld. [If Ag = 107.93, the data give P = 31.325, for Au = 196.67 the latter analyses give P = 31.176 and 31.165.] In all the experiments the precipitated metal'vas boiled with the solution when the reduction was nearly complete. A trace of gold was observed to precipitate after the experiments were over. The silver was heated to redness before weighing. [J. P. Cooke, Jr., has shown (atomic weight of antimony) that silver is volatile at a red heat. Berzelins must therefore have got too large a result.] The phosphorus was distilled, melted in a glass tube and cooled very slowly, to permit traces of oxides to rise to the surface, and the lower portion of the tube with the phosphorus broken off and instantly weighed. (Gilbert's Ann., 53, 1816, 433, and Lehrbuch 3, 1188.) J. PELOUZE: 32.024 (O = 16); 200.15 (O = 100). A known weight of argentic nitrate was brought in contact with a known and slightly excessive weight of phosphorous chloride and the excess titrated. The number of experiments is not given. Ag = 1349.01; Cl1 443.2. PHOSPHORUS. 97 The terchloride was prepared by chloridizing finely divided P with dry chlorine, adding finely divided P, decanting, agitation with tin amalgam and rectification over the same. The fluid was colorless and did not give any precipitate with water. (Paris, C(omptes Rend., 20, 1845, 1047.) V. A. JACQUELIN: 29.83 (O = 16); 186.438 (O = 100). Determined by experiments on the chlorides of phosphorus with argentic nitrate and plumbic oxide. The results are utterly discordant. (Paris, Comptes Rend., 33, 1851, 693.) A. SCHROETTER: 31.0274 (O = 16). Determined by burning perfectly pure amorphous phosphorus in dry oxygen and weighing the phosphoric anhydride. The number is the mean of 10 experiments; extreme dlifierence, 0.1242. Previous to burning, the phosphorus was heated for a long time in carbon di-oxide or hydrogen. It was burned not in powder but in lumps. (Erdmann's Journ. fiir Prak. Chem., 53, 1851, 435; Sitz.Bericht der k. k. Akad., 1851.) B. C. BRODIE: 31.31 (O = 16). Three experiments made by oxidation of phosphorus with aqua regia and determination as magnesium pyrophosphate gave this mean. Brodie seems to regard these determinations only as evidence that the atomic weight needs redetermination. (Journ. Chem. Soc., 5, 1852, 295.) J. DUMAS: 31.03 (O = 16). Determined by five experiments on the titration of the terchloride with argentic nitrate. The chloride was prepared by the action of dry chlorine on amorphous phosphorus and distillation after the chlorine had been displaced by carbon di-oxide. The portion distilling between 760 and 78~ only was used. The number is the mean of the results; extreme difference, 0.08. Ag = 108; Cl = 35.5. (Annal. de Chirm. et de Phys., (3,) 55, 1859, 172.) 7 98 ATOMIC WEIGHT DETERMINATIONS. PLATINUM. Regnault and Kopp have determined the specific heat of platinum. It answers to an atomic weight of about 197. (Gmelin-Kraut, 1. c.) J. J. BERZELIUS: 197.19 (O = 16). Determined by the same method as osmium, q. v., from a single experiment on potassium auroplatinate. 2,135 potassium chloride accompanied 2.822 platinum. [If KCI = 74.594 (Stas,) this gives the above value.]' The salt was prepared by precipitating an alcoholic solution of platinum chloride with potassium chloride, washing with alcohol and heating to redness in a current of chlorine. Berzelius remarks that the metal used in his former determinations was impure. (Poggend. Ann., 13, 1828, 468, and Lehrbuch, 3, 1213.) T. ANDREWS: 197.88 (O 16). Determined by three experiments on potassium chloroplatinate. The salt was dried at 105~ in vacuo, decomposed by zinc, the excess of zinc removed by acetic acid, the solution filtered off, and the chlorine titrated. The number is the mean; extreme difference, 0.22. The values assumed for Ag and C1 are not given. They were most likely Marignac's. (Brit. Assoc. Rep., 1852, part 2, 33.) J. S. Stas made preparations for determining the atomic weight of platinum, but not being able to produce potas siuni chloroplatinate entirely free from water, and being unacquainted with Bunsen's method of accomplishing this end, resigned the attempt. He made, indeed, three analyses by the same method employed by Berzelius, but unfortunately does not communicate the results. (Stas, Untersuch. iiber Chem. Prop., Leipzig, 1867, 265.) POTASSIUM. Regnault determined the specific heat of potassium. It corresponds to an atomic weight of about 39. (GmelinKraut, 1. c.) POTASSIUM. 99 M. H. KLAPROTH; F. H. WOLLASTON: 39.517 (O 16). Klaproth found that 441 C1= 591 potassium oxide. Hence Wollaston deduced the value 491 (O = 100) for K. [If C1 = 35.457, this relation gives K = 39.517.] (Phil. Trans., 104, 1814, 20.) J. J. BERZELIUS: 39.193 (O = 16); 244.958 (O = 100). Berzelius found that 100 KOC1= 192.4 Ag Cl. If Ag = 1351.607; C1 - 442.65; the above value follows. (Poggend. Ann., 8, 1826, 190.) F. PENNY: 39.073 (O = 16). Penny made six experiments on the conversion of the chlorate into the chloride. Potassic chlorate was dried at about 1050, dissolved in a flask with HC1, evaporated, dried and weighed. The cake contained some free HC1. It was broken up, pulverized, and a known quantity heated to dull redness but not to fusion, and the HC1 expelled allowed for. The mean result was that 100 KC1 03 -60.823 KC1l; extreme difference, 0.015. This relation gives C1 = — 74.527 and if C1l 35.454 (Penny,) the value for K follows. Numerous experiments were also made on the introconversion of the nitrate, the chloride and the chlorate, which established the difference between a chloride and a nitrate, besides confirming the value of K. The salts were purified by recrystallization and were carefully tested for impurities. The weighings are all for vacuum. (Phil. Trans., 129, 1839, 18.) C. MARIGNAC: 39.2 (O = 16); 245 (O = 100). By six experiments on the decomposition of the chlorate by heat, 100 chlorate were found to lose 39.161 oxygen; extreme difference 0.012; hence KC1 -- 932.14. By comparing this value with the molecular weight and the composition of argentic chloride, C1 was calculated at 442.13, leaving for K the number 490. Confirmatory experiments were made on potassic perchloride. The chlorate was purified by recrystallization. The weighings are for vacuum. (Liebig's Ann., 44, 1842, 23.) 100 ATOMIC WEIGHT DETERMINATIONS. C. MARIGNAC: 39.115 (0 = 16); 244.47 (O = 100). Having determined the atomic weight of chlorine fromn syntheses of argentic chloride, and found it 443.2, the molecular weight of KCl in the last determination, gives 1K= 244.47, for vacuum. Berzelius, by rejecting some analyses and the correction for vacuum, deduces the value 244.429. (Berzelius' Jahresbericht, 25, 1845, 31; Bibl. Univ. de Geneve, 46, 1842, 350.) J. PELOUZE: 39.144 (O = 16); 244.65 (O = 100). A known weight of KC1 was brought into contact with a known amount of silver dissolved in nitric acid, the chloride being slightly in excess. This excess was titrated with a decimal solution of silver. The number is the mean of three experiments. Ag = 1349.01; C1 = 443.2. The chloride was prepared by heating the chlorate and recrystallizing the residue. (Paris Comptes Bend., 20, 1845, 1047.) According to Pelouze, Levol found the molecular weight of KC1 466.245, which combined with Marignac's value of C1 would give K- = 244.645 or 39.143. (ibid.) E. J. MAUMENE: 38.96 (O =16); 243.502 (O - 100.) The mean of three experiments on the decomposition of KC1 with an excess of argentic nitrate showed that 100 KCl = 192.75 AgCI. If Ag = 1350.32 and C1 — 443.67, according to Maumene's determinations, the number follows. The KlC1 was prepared from the chlorate by heat. To confirm his values for K and Cl, he made seven experiments on the decomposition of the chlorate by heat, and found that 100 chlorate gave 60.791 chloride. An unaccounted for increase in the weight of the flask occurred in these experiments. (Annal. de Chim. et de Phys., (3,) 18, 1846, 41.) J. S. STAS: 39.137 (O = 16). According to the mean of seven determinations, 100 parts of KC1 dissolved in nitric acid, and evaporated to dryness give 135.6423 parts of nitrate; extreme difference, 0.017. If C1 — 35.457; N - 14.044; the value follows. This value is confirmed by previous experiments which gave 39.130. Potassic chloride, by whatever means it is prepared, still retains silica. Stas, therefore, determined RHODIUM. 101 the amount of silica in the ]KC1 and allowed for it. Weighings for vacuum. (Stas, Untersuch. iiber Chem. Prop., Leipzig, 1867.) Stas mentions that Dumas, who was the first to place K at 39, afterwards became convinced that this number was too low. (ibid, page 318.) RHODIUM. Regnault has determined the specific heat of rhodium. It corresponds to an atomic weight of about 104. (GmelinKraut, 1. c.) J. J. BERZELIUS: 104.3 (O 16 ). Berzelius made two analyses of dipotassic chlororhodiate. This salt can be completely desiccated in a current of chlorine at a red heat without decomposition. 3.146 grammes gave on reduction in a current of hydrogen 0.930 Cl, and the residue contained 1.304 KC1 and 0.912 metallic rhodium. [If KCI = 74.594, Cl = 35.457, (Stas,) the atomic weight of the salt calculated from the C1 contents is 359.831, and that of Rh 104.272. The relation between the Rh and the C1 gives Rh -104.312. The relation between the KOlC1 and the Rh gives Rh = 104.340. The mean is 104.308.] Berzelius made a second analysis of the crystallized salt in which he determined the water of crystallization. [Under the same suppositions and in the same order, the resulting values for Rh are 106.279; 104.762; 103.708.] In the Lehrbuch only the former analysis is used to deduce the atomic weight. Rhodium was separated from other metals by its insolubility in aqua regia. The double salt was formed by heating finely pulverized Rh in mixture with KC1 in a current of chlorine. The double salt was dissolved in water, precipitated with alcohol, washed with alcohol and dried. (Poggend Ann., 13, 1828, 437; Koingl. Vetens. Akad. Handl., 1828.) In his earlier determination (Rh = 750.68 for O = 100) Berzelius mistook an hydrated oxide for a chloride. (ibid.) 102 ATOMIC WEIGHT DETERMINATIONS. RUBIDIUM. Kopp determined the specific heat of rubidium chloride. It corresponds to an atomic weight of about 85. (GmelinKraut, 1. c.) KIRCHHOFF and BUNSEN: 85.36 (O = 16). Determined from the mean of four experiments on the precipitation of the chloride with argentic nitrate. The extreme difference was 0.24. Ag = 107.94; Cl - 35.46. An impure mixture of rubidium and potassium chlorides, nearly free from lithium and the earths, was partially precipitated with platinum chloride and the precipitate freed from KC1 by repeated boiling with water. The residue was reduced in a current of hydrogen, the rubidium chloride extracted with water, and reprecipitated with platinum chloride. This process was repeated until the potassium lines in the spectrum disappeared. The rubidium was then converted into a mixture of carbonate and oxide, and the caesium separated by extraction with alcohol. The amount of silver precipitated was also tested from time to time and the purification continued till this became constant. (Poggend. Ann., 113, 1861, 339.) J. PICCARD: 85.41 (O = 16). Determined by four analyses of rubidium chloride with argentic nitrate. The number is the mean; extreme difference, 0.09. The separation of potassium from rubidium was effected for the different analyses by 6, 7, and 8 successive partial precipitations with platinum chloride, and the separation of caesium by. thirty successive extractions of the anhydrous carbonates with warm absolute alcohol. The salt analysed was spectroscopically pure. Ag = 107.94; C1= 35.46. The experiments were made with Bunsen's assistance. (Erdmann's Journ. fiir Prak. Chemn., 86, 1862, 449.) L. Grandeau, who is sometimes credited with making a determination of Rb, expressly disclaims doing so. He mentions Bunsen's value as the true atomic weight and says that his analyses of the sulphate, undertaken to test its purity, led him to adopt the number 85.4; apparently for brevity's sake. (Annal. de Chim. et de Phys., (3,) 67, 1863, 227.) SELENIUM. 103 R. GODEFFROY: 85.476 (O = 16). Determined by four analyses of rubidium chloride prepared and analysed exactly as Godeffroy determined coesium, q. v.; extreme difference, 0.04. C1 = 35.5; Ag = 108. (Liebig's Ann., 181, 1877, 189.) RUTHENIUM. Bunsen has determined the specific heat of ruthenium. It corresponds to an atomic weight of about 104. (GmelinKraut, 1. c.) C. E. CLAUS: 104.57 (O = 16). Determined from three analyses of potassium chlororutheniate by the same method Berzelius had employed for other platinum metals. Claus found an average of 28.783 per cent. Ru; extreme difference 0.48, and 41.063 KC1; extremne difference, 0.51. [If: — 39.137, Cl = 35.457; this composition gives Ru 104.57. Tile weighings as given illn the memoir are misprinted.] Claus also determined the chlorine with silver; the results were such as to show that the salt was not anhydrous, though it had been dried at 200~ in an atmosphere of C1. The salt was prepared by the evaporation of a solution of ruthenium and potassic hydrate in aqua regia, solution of other chlorides of Ru in dilute HCI, and removal of basic compounds by mechanical concentration in water. Claus later takes the atomic weight of Ru = 104. In this memoir he puts it at 651.387 (O = 100,) 104.22 (O = 16,) without mentioning the values of K and C1. (Poggend. Ann., 65, 1845, 218.) SELENIUM. Regnault determined the specific heat of selenium, which accords with an atomic weight of about 79. (Gmelin-Kraut, 1. c.) 104 ATOMIC WEIGHT DETERMINATIONS. J. J. BERZELIUS: 79.23 (O = 16). Berzelius found that 100 Se absorb 179 dry chlorine gas, and that the product was exactly decomposed by water into chlorhydric acid and selenious acid. [If Cl = 35.457 (Stas) the value follows.] (Pogyend. Ann., 8, 1826, 21.) F. SACC: 78.55 (O - 16); 490.93 (O = 100). Sacc's experiments are very discordant. He made three experiments on the reduction of a known weight of selenious acid with ammonium bisulphite and chlorhydric acid. The mean result was Se = 490.38; extreme difference, 5.5. In four experiments barium seleniate was decomposed by heating to redness with sulphuric acid in excess. The salt was found to contain 41.95 selenious acid; extreme difference 0.04. For Ba - 856.877 the resulting value is 491.49. The selenium was purified by solution in nitric acid, evaporation and sublimation, and by reduction with HC1 and ammonium bisulphite. Selenious acid was prepared by oxidation with nitric acid. Barium seleniate was prepared by precipitation of barium nitrate with sodium seleniate and heating to redness. Sacc regards 490.3 as the most probable value of Se. (Annal. de C(him. et de Phys., (3,) 31, 1851, 119.) A. SCHROETTER: 78.6 (O = 16). Details not given. (Kopp's Jahresbericht, 4, 1851, 318; Sitz.-Bericht der k. k. Acad., 6, 1851, 214.) ERDMANN AND MARCHAND: 78.6 (-0 16); 492.5 (O = 100). Determined from experiments on mercuric selenide by the same methods employed for the determination of S, q. v. Three experiments gave 71.726, 71.731, 71.741, per cent. mercury. (Erdmann's Journ. fiir Prak. Chem., 55, 1852, 202.) J. DUMAS: 76.46 (O = 16). Determined by seven experiments on the chloridation of selenium. The chloride was condensed in a tube cooled to - 200, after which the escaping gases were led through other tubes filled with asbestos. The extreme difference in the results was 0.46. Cl = 35.5. (Annal. de Chim. et de Phys., (3,) 55, 1859, 129.) SILICON. 105 O. PETTERSSON and G. EKMAN: 79.08 (O = 16). Determined by five analyses of selenious acid. A warm solution of the acid was acidified with chlorhydric acid, precipitated with sulphurous acid and the selenium collected on a glass filter. Many precautions are necessary in the precipitation and drying. The value is the mean; extreme difference, 0.04. (Berlin, Bericht der Chem. Gesell., 9, 1876, 1212; in extenso in the Acta of the Scientific Soc. of Upsala.) SILICON. The vexed question of the composition of silicic acid has been settled by -I. F. Weber, who found that the specific heat of this element becomes nearly constant above 200~ and that the atomic heat is 5.8 for Si= 28. (Poggend. Ann., 154, 1875i 575.) J. J. BERZELIUS: 29.63 (O = 16); 185.19 (O = 100). 100 parts of silicon, which had been heated to redness, and freed from silicic acid by hydrofluoric acid, gave 208 parts silicic acid, whence the value. Berzelius also made analyses of barium fluosilicide from which he calculated the oxygen contents of the acid at 51.975. This gives for the atomic weight of Si 29.58. (Poggend. Ann., 8, 1826, 20; and Lehrbuch, 3, 1200.) J. PELOUZE: 28.46 (O = 16); 177.88 (O = 100). A known weight of perfectly pure silver, dissolved in nitric acid, was brought in contact with a known and slightly -excessive weight of silicon tetrachloride and the excess titrated with decimal silver solution. The value is derived from the mean of two experiments; difference 0.76 for O = 100; Cl = 443.2, Ag = 1349.01. The chloride was prepared by Ebelmen; it was perfectly transparent, volatilized without residue, and had been dried for a long time in a vacuum. (Paris, Comptes Rend., 20, 1845, 1047.) J. DUMAS: 28.02 (O = 16). Determined from the mean of two experiments on the tetrachloride which was weighed off in a glass bulb and 106 ATOMIC WEIGHT DETERMINATIONS. introduced, so enclosed, into a vessel containing water. The bulb was broken and the chlorine contents titrated with argentic nitrate. The difference between the experiments was 0.2 for O = 16, Ag = 108, C1 - 35.5. The chloride was repeatedly rectified; its boiling point was 59~. (Annal. de Chim. et de Phys., (3,) 55, 1859, 129.) J. SCHIEL: 28.01 (O = 16). Determined by two analyses of the tetrachloride. The salt was decomposed with a slight excess of ammonium hydrate and the chlorine titrated with argentic nitrate. The atomic weights of C1 and Ag used are not stated. Schiel found 0.6738 silicic chloride _ 2.277 argentic chloride, and 1.3092 silicic chloride = 4.418 argentic chloride. [For Ag =107.93, Cl= 35.457, these data give Si= 28.13, and 27.89.] (Liebig's Ann., 120, 1861, 94.) SILVER. Dulong and Petit, Regnault and others have determined the specific heat of silver and found it in accord with an atomic weight of about 108. (Gmelin-Kraut, 1. c.) MARCET; DAVY; WENZEL; WOLLASTON. Wollaston in his table of equivalents mentions that Marcet found 441 C1 = 1350 silver, and Davy the same quantity of chlorine - 1360 silver. Wenzel found 200 sulphur = 1360 silver. (Phil. Trans., 104, 1814, 21.) J. J. BERZELIUS: 108.1 29 (O =16); 675.804 (0= 100). Berzelius found that 100 silver gave 132.75 argentic chloride. Taking C1 = 221.325 he calculates Ag = 1351.607. He expresses uncertainty whether or no this value should not be reduced to one half. (Poggend. Ann., 8, 1826, 180.) E. TURNER: 108 (O- = 16). Turner determined the composition of argentic chloride at 100 silver to 132.8 chloride. These numbers are for SILVER. 107 vacuum. If C1 =35.42 (Turner) the value follows. (PPhil. Trans., 123, 1833, 536.) F. PENNY: 107.97 (O = 16). Penny made six experiments on the conversion of silver into nitrate. The silver was dissolved in cold nitric acid, the solution evaporated, and the nitrate fused all in one flask and with precautions against loss by spiriting. He found 100 Ag = 157.441 nitrate; extreme difference, 0.028. In five experiments the nitrate from the preceding determinations was converted into chloride, by means of chlorhydric acid, in the same flask, dried, fused, and weighed. Penny could detect no decomposition in fusion. HIe found 100 Ag = 132.8372 chloride; extreme difference, 0.01. In two experiments silver was dissolved in nitric acid, precipitated with chlorhydric acid, evaporated and fused, giving 132.830 and 132.838. The mean of all seven experiments is 132.836. Penny takes 132.837. From the relations of the chlorides, chlorates, and nitrates of potassium and sodium, Penny had determined the difference between the atomic weights of a chloride and a nitrate at 26.565. This gives the molecular weight of argentic chloride at 143.424 and Ag = 107.97. The silver used, as well as the water and the acids, were carefully tested for impurities and a minute amount of solid residue in the twice distilled water and in the acids was allowed for. The weighings were all reduced to vacuum. (Phil. Trans., 129, 1839, 27.) C. MARIGNAC: 108 (O -- 16); 675 (O = 100). Silver was dissolved in nitric acid and precipitated with chlorhydric acid. One experiment, reduced to vacuum, gave 100 silver =- 132.74 chloride, which Marignac considered confirmatory of Berzelius' value, 132.75. Ile therefore adopted the latter number. 100 potassic chloride were found to produce 192.26 argentic chloride, in two experiments, the difference between which was 0.01. By analysis, by means of heat, of potassic chlorate, Marignac had found the molecular weight of the chloride 932.14, these relations give the molecular weight of argentic chloride at 1792.13 and the atomic weight of silver at 1350. The potassic chloride was prepared by heating the chlorate and cooling the resulting chloride over sulphuric acid. (Liebig's Ann., 44, 1842, 23.) 108 ATOMIC WEIGHT DETERMINATIONS. C. MARIGNAC: 107.922 (O = 16); 674.505 (O = 100). Marignac redetermined the relation between silver and potassic chloride by Pelouze's method. He found 100 Ag = 69.062 KIC1 in six experiments, the extreme difference between which was 0.018. In five experiments he found 100 KCI C 192.348 Ag; extreme difference 0.04. He also redetermined the composition of argentic chloride. The silver was dissolved in a long-necked flask and the fumes passed into a second flask containing water. Solution being effected, the water from the second flask was added to the contents of the first, and the whole precipitated with HCl. The chloride was washed, dried, melted and weighed in the same flask. The result was 100 Ag = 132.84 chloride; extreme difference 0.019. Combination of these data with Marignac's old value for the molecular weight of K1Cl, 932.14, gives Ag = 1349.01. All weighings reduced to vacuum. Berzelius revised the result by throwing out one experiment and by rejecting the correction for vacuum. HIe thus got Ag =- 1349.66. (Berzelius' Jahresbericht, 24, 58; 25, 31; Bibl. Univ. de Genece, 46, 1842, 350.) In opposition to Prout's hypothesis, Marignac cites his analyses of argentic acetate, in which the escaping gases were forced to pass over porous silver. They gave in three experiments 64.664 silver from 100 acetate; extreme difference 0.005. If C = 75, this gives Ag = 1349.6. He also found 100 Ag = 157.455 nitrate. [If N = 87.5, this gives Ag = 1348.88.] He also found 100 Ag = 49.556 ammonium chloride. (Liebig's Ann., 59, 284; Bibl. Univ. de Geneve, 1846.) LIEBIG and REDTENBACHER; STRECKER: 107.903 (O = 16); 674.395 (O = 100). Strecker recalculated Liebig and Redtenbacher's analyses of argentic acetatec tartrate, racemate and malate by the method of least squares, and from the difference in the atomic composition of these salts. He obtained for Ag the value 1348.79. Vide Carbon. (Liebig's Ann., 59, 1846, 280.) E. J. MAUMENE: 108.026 (O = 16); 675.16 (O100). In four experiments argentic oxalate was mixed with sand in a flask and decomposed by heat in a current of air. The SILVER. 109 products of decomposition were passed over cupric oxide, and through drying tubes and potash tubes. In five experiments the acetate was treated in the same way, but not mixed with sand. The mean result was Ag - 1350.32; extreme difference 0.77. Maumene found it very difficult to purify the oxalate, which showed traces of nitric acid after 100 washings. (Annal. de Chim. el de Phys., (3,) 18, 1846, 41.) J. S. STAs: 107.93 (O = 16). Thirteen syntheses of argentic iodide, performed by bringing hydroiodic acid in contact with argentic sulphate or nitrate, gave 100 Ag = 117.5343 iodine. Three analyses of argentic iodate, performed by decomposition by heat in a current of nitrogen or by reduction of the salt, while in suspension, by a current of sulphurous anhydride, gave Ag =- 234.779. Hence Ag = 107.928. Four syntheses of' the bromide, performed by bringing hydrobromic acid in contact with argentic sulphate, gave 100 Ag = 74.0805 Br. Two analyses of argentic bromate, by reduction while in suspension with sulphurous anhydride, gave Ag Br= 187.87. Hence, Ag - 107.921. Seven syntheses of argentic chloride, three of them by combustion of silver in chlorine, three by precipitation with HC1, and one by precipitation with ammnonium chloride, gave 100 Ag = 32.8445 C1. Stas adopts the number 32.85 on the supposition that no excess of chlorine was possible. The chloride was fused. Two analyses of the chlorate, accomplished by heat or by evaporation with chlorhydric acid, gave Ag Cl = 143.395. Hence Ag =107.937. Five syntheses of the sulphide, performed by heating silver in a current of sulphur vapor, or of hydrogen sulphide, gave 100 Ag = 114.8522 argentic sulphide. Six analyses of the sulphate by reduction in a current of hydrogen, showed that 100 sulphate contained 69.203 silver, hence Ag =107.920, [107.926? vide Sulphur.] From analysis of potassium chlorate, Stas had determined the molecular weight of KC1 at 74.59. By twenty-four determinations he found 100 Ag = 69.103 KC1, hence Ag = 107.943. The silver was prepared either by Levol's method or by decomposing an ammoniacal solution of argentic nitrate with a mixture of ammonium sulphite and a copper salt.. The metal was heated to the boiling point until the sodium line disappeared and the metallic fumes were a pale blue. To test its purity, it was compared with distilled silver. See Stas's determinations of C1, Br, I, S, 110 ATOMIC WEIGHT DETERMINATIONS. and 1K. All weighings reduced to vacuum. (Stas, Untersuch. iiber Chem. Prop., Leipzig, 1867.) SODIUM. The specific heat of sodium has been determined by Regnault and indicates an atomic weight of about 23. (GmelinKraut, 1. c.) H. DAVY; F. H. WOLLASTON: 23.28 (O = 16); 145.5 (O = 100). Davy found that 134 C1 combine with 88 Na to form sodium chloride. If C1 - 441, the value follows. (Phil. Trans., 104, 1814, 20.) J. J. BERZELIUS: 23.164 (O = 16). Berzelius found that 100 Na Cl 244.6 Ag Cl. [If Ag Cl =143.387, (Stas,) the value follows.] (Poggend. Ann., 8, 1826, 189.) F. PENNY: 23.046 (O = 16). Penny made four experiments on the conversion of the chlorate into the chloride by means of HC1. A known weight of the salt was dissolved in a flask in the acid and evaporated, dried and weighed without removal. The sodium chloride was not fused. The mean result was that 100 chlorate equals 54.930 chloride; extreme difference, 0.02. This relation gives the molecular weight of the chloride at 58.5. Penny had found the atomic weight of C1 = 35.454; hence the value for Na. [If C1- 35.457 (Stas,) Na23.043. Stas himself found 23.043.] The sodium chlorate was prepared by precipitating potassium chlorate with sodium bitartrate, and purifying the sodium chlorate by recrystallization. The weighings are for vacuum. (Phil. Trans., 129, 1839, 25.) J. PELOUZE: 22.97 (O = 16); 143.59 (O — 100). A known weight of perfectly pure silver was dissolved in nitric acid, and brought in contact with a known and STRONTIUM. 111 slightly excessive weight of sodium chloride, and the excess titrated with decimal silver solution. The mean result of three experiments was that 100 Ag = 51.141 Na Cl; extreme difference, 0.033. The value follows for Ag= — 1349.01; C1 = 443.2. The sodium chloride was prepared either from sodium sulphate and barium chloride, or from sodium carbonate and chlorhydric acid, or from a very pure rock salt. It was repeatedly recrystallized and was dried at 200~ or melted. (Paris Comptes Bend., 20, 1845, 1047.) J. DUMAS: 23.011 (O = 16). Determined from the mean of seven experiments on the titration of sodium chloride with argentic nitrate; extreme difference, 0.09. Ag — 108; Cl = 35.5 [Dumas gives the mean as 23.014 instead of 23.0114.] For five experiments Na C1 recrystallized ten times and melted was employed. For two experiments (giving an average of 23.036) the residue from the incineration of the acetate was used to prepare Na Cl, which was recrystallized four times and melted. (Annal. de Chim. et de Phys., (3,) 55, 1859, 129.) J. S. STAS: 23.043 (O = 16). According to the mean of 10 determinations 100 Ag = 54.2078 Na Cl; extreme difference 0.0033. The sodium chloride was found to contain a minute quantity of silicic acid which reduces the result from Na — 23.049 to 23.045 for Ag = 107.93; Cl = 35.457. According to the mean of five determinations 100 Na Cl - 145.4526 sodium nitrate; extreme difference 0.025. If N = 14.044 this gives Na 23.045. The lowest determination gives Na = 23.042. The sodium chloride was purified by recrystallization and in part by conversion into sodium chloroplatinate. The weighings are for vacuum. (Stas, Untersuch. iiber Chem. Prop., Leipzig, 1867.) STRONTIUM. Regnault determined the specific heat of strontium chloride. It corresponds to an atomic weight of about 87.5. (Gmelin-Kraut, 1. c.) 112 ATOMIC WEIGHT DETERMINATIONS. M. II. KLAPROTH; F. II. WOLLASTON: 94.4 (O = 16); 590 (O = 100). Klaproth found 42 sulphuric anhydride = 58 strontium oxide; whence the value for S = 200. (Phil. Trans., 104, 1814, 20.) F. STROMEYER; 87.34 (O = 16); 545.929 (O - 100). According to Berzelius, Stromeyer found that 100 strontium chloride - 181.25 argentic chloride; whence the value, for Ag =- 1349.66; C1 221.64. (Berzelius' Lehrbuch, 3, 1229.) In Gilbert's Ant., 54, 1816, 251, Stromeyer refers to this analysis as by V. Rose. Stromeyer himself found 0.5 grin. carbonate= 75.5394 c. c. carbon di-oxide [which gives Sr = 88.26 if 1000 c. c. carbon di-oxide weigh 1.96433 grm.] Stromeyer calculated Sr = 552.28 for O - 100.. SALVETAT: 88 (O = 16); 550 (O = 100). Determined from the loss of weight of strontium carbonate by calcination and on driving off carbon di-oxide with sulphuric acid. Details not given. (Paris C(omptes Rend., 17, 1843, 318.) J. PELOUZE: 87.68 (O = 16); 548.02 (O = 100). A known weight of perfectly pure silver was brought in contact with a known and slightly excessive amount of strontium chloride and the excess titrated with decimal silver solution. The number is the mean of two experiments; extreme difference, 0.2. Ag 1349.01; C1443.2. The chloride was purified by recrystallization and was dried at 200~ or below redness. (Paris Comptes Rend., 20, 1047.) C. MARIGNAC: 87.54 (O = 16). Marignac made experiments on three different preparations of strontium chloride, (1,) (2,) (3.) Compared with silver by Pelouze's method it was found that ten grammes strontium chloride = -(1) 8.103; (2) 8.099; (3) 8.101 silver. The same strontium chloride converted into sulphate gave (1) 6.887; (2) 6.8855; (3) 6.884 sulphate. In both these series of experiments the strontium was weighed as airdried, hydrous, crystalline chloride. Comparison gives Sr SULPHUR. 113 = (1) 43.79; (2) 43.82; (3) 43.77. In each experiment of the latter series the water was determined by driving it off at a red heat. It was proved that the chloride does not undergo decomposition at this temperature, and the water contents was found to vary no more than 0.0005 of the total weight. In three more experiments the water was determined, and the anhydrous salt analysed by Pelouze's method giving (1) 43.77; (2) 43.74; (3) 43.76. Ag = 108; C1= 35.5; S = 16. The chloride was prepared (1) from the chemically pure chloride of commerce by precipitating barium with sulphuric acid, separation of linie by precipitation of the strontium chloride by HC1 gas and washing with chlorhydric acid. The purity was tested by the solubility of a portion converted into sulphate. The chloride was finally redissolved and precipitated with alcohol. (2) was prepared from (1) by a repetition of the same process. (3) was prepared front (2) by recrystallization. (Bibl. Univ., Arch. des Sciences, (2,) 1, 1858, 220.) J. DUMAS: 87.52 (O = 16). Determined from the mean of six experiments on the analysis of strontium chloride with argentic nitrate. The extreme difference was 0.14, C1= 35.5; Ag = 108. The salt was purified by boiling with sulphuric acid, and precipitation with and recrystallization from chlorhydric acid. These processes were in some cases several times repeated. The pure salt was fused in a current of 1CI gas. (Annal. de Chirn. et de Phys., (3,) 55, 1859, 129.) SULPHUR. Deville and Troost and others have determined the density of sulphur in the gaseous form. It corresponds to an atomic weight of about 32. The specific heat of sulphur also agrees moderately well with this value. (Gmelin-Kraut, 1. c.; L. Meyer, 1. c.) J. J. BERZELIUS; F. H. WOLLASTON: 32 (O- = 16); 200 (0= 100). According to Wollaston, Berzelius found that plumbic sulphide was composed of 86.64 lead and 13.36 S. Hence the value, for lead = 1295. (Phil. Trans., 104, 1814, 20.) 8 114 ATOMIC WEIGHT DETERMINATIONS. J. J. BERZELIUS: 32.19 (0 - 16) 201.165 (O = 100). A known weight of lead was disso'lved in pure nitric acid, precipitated with sulphuric acid and evaporated. The mean result of four experiments was that 100 Pb = 146.44 sulphate. The variation was only in the fifth figure. If lead = 1294.498 the value follows. [If this relation is recalculated with Stas's.atomic weight of lead, S = 32.096.] (Poggend. Ann. 8, 1826, 16.) E. TURNER: 32.17 (O = 16). Determined from syntheses of plumbic and baric sulphates. The former gave 16.083, the latter, 16.087. Ba 68.7, Pb = 103.6. The numbers are for vacuum. Vide Barium and Lead. (Phil. Trans., 123, 1833, 539.) T. THOMSON: 32 (O- 16); 200 (O = 100). This chemist found the specific gravity of sulphurous acid in mean of two experiments, 2.22216, almost exactly double 1.1111 which he takes (on utterly untenable grounds) for the specific gravity of oxygen. (Erdmann's Journ. fiir Prak. Chem., 8, 1836, 370; Records of General Science by R. D. Thomson, 1836, 179.) ERDMANN and MARCHAND: 32.004 (O = 16); 200.026 (O = 100). Determined by four experiments on the decomposition of mercuric sulphide by copper, in a current of carbon dioxide, the mercury being caught in a cold receiver. The mean composition was found to be for vacuum 86.211 mercury and 13.789 sulphur, extreme difference, 0.017 Hg. If I-Ig- 1250.6, the value follows. In purifying the sulphide it was first heated to drive off excess of sulphur and then sublimed three times, the first and last portions of the sublimate being rejected. (Erdmann's Journ. fiir Prak. Chem., 31, 1844, 396.) J. J. BERZELIUS: 32.12 (O = 16); 200.75 (O -- 100). Berzelius' former value, 201.165, is changed by the new value for lead, 1294.645 to 200.8017. Three new experiments were made by gently heating argentic chloride in a current of hydrogen disulphide. The mean of three experiments gives - = 200.706; extreme difference 0.11. C1 = 443.38, Ag = 1349.66. (Berzelius' Jahresbericht, 25, 1845, 37, and Lehrbuch, 3, 1185.) SULPHUR. 115 H. STRTJVE:.3'2.002 (O = 16). Determined by six experiments on the reduction of a known weight of argentic sulphate in a current of hydrogen. The number is the mean; extreme difference, 0.146. Ag= 108. The sulphate was prepared by precipitating the nitrate with an excess of sulphuric acid, and drying at a high temperature. (Liebig's Ann., 80, 1851, 203; Berzelius' Jahresbericht, 30, 20.) J. DUMAS: 32.0196 (O = 16). Determined by five experiments on the combustion of silver in sulphur vapor. The number is the mean; extreme difference, 0.054. Ag -108. The sulphur was purified by repeated distillation. The silver was heated to redness in a current of sulphur vapor, the excess of sulphur being afterwards distilled off in a current of carbon di-oxide. (Annal. de Chim. et de Phys., (3,) 55, 1859, 147.) J. S. STAS: 32.0742 [?] (O = 16). According to the mean of six analyses of argentic sulphate by decomposition in a current of hydrogen at as low a temperature as possible, 100 sulphate yield 69.203 [mnore exactly 69.20317] silver; extreme difference, 0.012. Five syntheses of the sulphide, performed by heating silver in a current of sulphur vapor or hydrogen disulphide, showed that 100 silver = 114.8522 sulphide; extreme difference, 0.005. By comparing these figures, which are for vacuum, Stas deduces S — 32.0742; Ag = 107.920. [There seems to be a trifling error in this calculation. The weighings seem to be correct, for the means correspond to the details given. As given, the numbers indicate S = 32.058; Ag = 107.926. The latter is almost identical with Stas's mean value, 107.930.] The sulphate was prepared by the action of sulphuric acid on argentic nitrate, or by solution of silver in sulphuric acid. The salt was heated above the boiling point of sulphuric acid. (Stas, Unters. ilber Chem. Prop., Leipzig, 1367.) 116 ATOMIC WEIGHT DETERMINATIONS. TANTALIIJM. Deville and Troost have determined the vapor density-of tantaliurn chloride. It agrees with an atomic weight of 182. (Paris Cornptes Rend., 64, 1867, 294.) J. J. BERZELIUS: ~167.74 (O - 16). Berzelius decomposed the sulphide in dry chlorine gas and decomposed the resulting chloride with water. 99.75 parts sulphide yielded 89.35 tantalic acid. On the supposition that the acid contains three atoms of oxygen Berzelius calculates the atomic weight at 1148.365 for S = 200.75. [If the acid contains five atoms of oxygen the value becomes 167.74.] (Poggend. Ann., 4, 1825, 14, and Lehrbuch, 3, 1209.) Rose denies that the sulphide formed, as Berzelius prepared it, by heating tantalium in carbon disulphide vapor is a constant compound. (Poggend. Ann., 99, 580.) Marignac, however, shows that Berzelius, Rose and Hermann, obtained constant results from its analysis, from 89.50 to 90 acid from 100 sulphide. If Ta -182, the sulphide would give 90.24 acid. (Liebig's Ann., S, 4, 1866, 358.) H. ROSE: 172 (O - 16). Out of twelve analyses of the chloride, in which both the chlorine and the tantalic acid were determined, Rose selected two in which the agreement was best. [These analyses calculated for Ag = 107.93, Cl = 35.457, give Ta = 171.96.] The chloride was prepared from tantalic acid especially freed from tungsten antd tin by mixing with carbon, drying in carbon di-oxide, and heating in a current of chlorine in which the salt was allowed to cool. Excess of chlorine was expelled by dry air, and the salt was hermetically sealed in glass. Rose supposed the acid to contain two atoms of oxygen and therefore deduces the value 859.81 (O = 100). (Poggend. Ann., 99, 1856, 75.) Marignac seems to prove that the material with which Rose dealt contained niobium. He states that the chlorides of the two elements cannot be separated from one another, and that there are no characteristics by which their purity can be decided. (Liebig's Ann., S, 4, 1866, 352.) TELLURIUM. 117 R. HERMANN: IHermann made many analyses of tantalium salts to which, however, he ascribes quite incomprehensible formulas. Marignac has shown that his methods were utterly inadequate to produce pure preparations. He assumes two atoms of tantalium and three atoms of oxygen in the acid and gives the atomic weight as 645. (O = 100.) (Erdmann's Journ. fur Prak. Chem., 70, 1857, 193.) C. MARIGNAC: 182 (O = 16). Berzelius', Rose's and Marignac's analyses of the double fluoride of tantaliumn and potassium show that the fluorine is combined with Ta and potassium in proportions of two to five. The salt has also exactly the crystal form of the niobium salt. Hence the acid is a ditantalic pentoxide. Four experiments were made on this salt by drying at 1000, moistening with sulphuric acid and heating gradually till the excess of acid was driven off. The potassic;sulphate was leached out, evaporated, melted and weighed, and the tantalic acid heated to redness and weighed. The mean potassic sulphate contents was found to be 44.29 per cent; extreme difference, 0.15. The mean amount of tantalic acid obtained was 56.59; extreme difference, 0.25. If K = 39, these data give Ta = 182.3. Four analyses were also made of the ammonium salt. This contained traces of potassium which were determined and allowed for in each case. The mean amount of tantalic acid obtained was 65.25 per cent; extreme difference, 0.34. This gives Ta = 182, the number which Marignac adopts. The salts were obtained by dissolving tantalic acid, which had not been heated to redness, in fluohydric acid, adding potassic or ammnonic hydrate and purifying by recrystallization. These salts are much less soluble than the corresponding niobium and titanium salts. (Liebig's Ann., S. 4, 1866, 234.) TELLURIUM. Regnault and Kopp have each determined the specific heat of tellurium and found it in accord with an atomic weight of about 128. (Gmelin-Kraut, 1. c.) 118 ATOMIC WEIGHT DETERMINATIONS. J. J. BERZELIUS 129.03 (O = 16); 806.452 (O = 100). A known weight of metallic tellurium was oxidized with nitric acid, the excess of acid being driven off by heat. It was found that 100 Te gave 124.8 tellurious acid. (Poggend. Ann., 8, 1826, 24.) J. J. BERZELIUS: 128.28 (O = 16); 801.76 (O100). Determined as before but with purer material. Three experiments were made, which gave 802.838, 801.786, 801.74. Berzelius took the mean of the latter two. The tellurium was prepared from tetradymite by heating with potassium carbonate and olive oil in a closed crucible, dissolving the potassium telluride so formed in water free from air, precipitating the tellurium by a current of air and distilling it in a current of hydrogen. (Poggend. Ann., 32, 1834, 16.) K. VON HAUER: 128.06 ( O - 16). Determined from the mean of five experiments on the precipitation of bromine with argentic nitrate from the double bromide of potassium and tellurium. The bromine contents was found to be 69.9236 per cent., for Ag = 108.1; Br = 80; extreme difference 0.172. If K = 39.2, the value follows. The salt was prepared by mixing tellurium and potassic bromide in atomic proportions, adding water and bromine, heating to drive off excess of bromine and repeated recrystallization. (.Erdmann's Journ. fiir Prak. Chem., 73, 1858, 98; Sitz-Bericht der k. k. Acad.) J. DUMAS: 129 (O = 16). No details are given. (Annal. de Chim. et de Phys., (3,} 55, 1859, 129.) THALLI UM. Regnault determined the specific heat of thallium. It agrees with an atomic weight of 204. (Gnmelin-Kraut, 1. c.) A. LAMY: 204 (O = 16). Three analyses of the chloride with argentic nitrate gave THALLIUM. 119 a mean of 204; extreme difference 1.2. An experiment on the precipitation of the sulphate with barium nitrate gave 204.3. [The atomic weights used were probably those accepted by Dumas.] The salts were purified by recrystallization. (Annal. de Chim. et de Phys., (3,) 67, 1863, 411.) W. CROOKES: 202.96 (O = 16). These determinations were made from the sulphate, which was prepared with great care. By decomposing the sulphate with potassic iodide and weighing the thallic iodide formed, the atomic weight was found at 202.73; by precipitation with barium nitrate, 203.55; with chlorhydric acid and alcohol, thallic chloride being weighed, 201.85; from the amount of sulphate produced from a known weight of metal, 203.1; by precipitation with platinum chloride, 203.56. The values taken for Cl, I, etc., are not given; [they were probably those accepted by Dumas.] (Erdmann's Journ. fiir Prak. Chem., 92, 1864, 277; Chem. News.) H. WERTHER: 204 (O = 16). In five experiments Werther decomposed thallic iodide with potassic hydrate and zinc, both perfectly pure, and precipitated the iodine with silver. The mean result of these experiments was T = 204.4; extreme difference 1.7. [The value assumed for I is not stated. One experiment, which gave exactly 204, according to Werther, recalculated for Ag = 107.93; I = 126.85 gives Ti = 203.63.] Three experiments were made by decomposing the iodide with ammoniacal solution of argentic nitrate and weighing the argentic iodide formed. These determinations gave Tl - 203.47; extreme difference 0.3. The preparation of the iodide is not given. (Erdmann's Journ. fiur Prak. Chem., 92, 1864, 136.) M. HEBBERLING: 203.94 (O = 16). Hebberling made three experiments on the sulphate by precipitation with barium chloride, which gave in mean TI = 204.13; extreme difference 0.2. HIe also made two experiments on the chloride by precipitation with argentic nitrate. These gave 203.8 and 203.5. The atomic weights assumed are not stated. [If Ag = 107.93; C1 = 35.457; the first analysis of the chloride gives Ti = 203.44. The data for the second analysis are misprinted. If a probable correction of a single figure is made, the data give T = 120 ATOMIC WEIGHT DETERMINATIONS. 203.026.] The salts were purified by recrystallization. (Liebig's Ann., 134, 1865, 11.) W. CROOKES: 204.155 (O - 16). Determined by experiments on the solution of metallic thallium in nitric acid and evaporation to dryness. The number is the mean of ten experiments; extreme difference, 0.038. The balance stood in a partial vacuum, and the weighings were made at two different pressures and calculated for vacuum. Very elaborate precautions were taken throughout. CrQokes also mentions determinations made with barium nitrate, but gives no data. The thallium was prepared in seven different lots by the reduction of as many different salts which had been purified by recrystallization &c. The metal was fused in lime. The reagents were expecially prepared by methods similar to those of Stas. Crookes took N = 14.009, 0 -- 15.96, and calculated for T1 the value 203.642. [If O = 16, the value becomes 204.155.] (Phil. Trans., 163, 1873, 277.) THORIUM. From the isomorphism existing between thorium, tin, and titanium, and from the similarity of thorium to zirconium, Delafontaine and Marignac believe the oxide to contain two atoms of oxygen. (Liebig's Ann., 131, 100.) Neither the specific heat of this element nor the vapor density of any of its compounds has been determined so far as I know. J. J. BERZELIUS; 238 (O -- 16); 1887.72 (O = 100). From the sulphate, precipitated by heating a solution of the salt and redissolved in cold water, Berzelius got the values 748.493 and 735.713 by precipitating with barium chloride. He also analysed the double sulphate of potassium and thorium. From the relation between the sulphuric acid and the thorium oxide found, the atomic weight would seem to be 750.63, while the relation between the potassic sulphate obtained, and the amount of oxide gives 740.6. These numbers are calculated on the supposition that the oxide contains a single atom of oxygen. Ba - THORIUM. 121 855.29, S = 200.75, K = 488.856. (Poggend. Ann., 16, 1829, 8398, and Lehrbuch, 3, 1224.) J. J. CHYDENIUS: 236.64 (O = 16). This chemist analysed the sulphate, the double sulphate -of potassium and thorium, the oxalate, the acetate and the formate, getting results which vary from 228.52 to 243.76. He averages with his own results analyses made by Berzelius and by Berlin, which, however, alter the result inappreciably. According to Delafontaine, the methods employed for purification are ineffectual. Chydenius assumes a single atom of oxygen in the oxide. (Poggend. Ann., 119, 1863, 55.) N. J. BERLIN: 231.64 (O = 16). Chydenius reports two analyses of the oxalate by Berlin which gave for thorium 57.87 and 57.95, or 231.48 and 231.80. (Poggend. Ann., 119, 1863, 56.) M. DELAFONTAINE: 231.5 (O = 16). Determined from analyses of the sulphate. Fourteen experiments on the decomposition of this salt, by the heat of a strong double-draught lamp, gave a mean of 52.51 per cent. oxide; extreme difference, 0.83. In three experiments the sulphur contents of the salt was determined by precipitation with barium chloride after the sulphate had been decomposed with ammonium oxalate. The mean amount of sulphuric anhydride so found was 31.92 per cent.; extreme difference, 0.78. Three experiments on the water contents gave 15.68 per cent; extreme difference, 0.21. The sum of these means is 100.11. The value of thorium was calculated from the relation of the oxide to the sulphuric anhydride for S = 32, Ba = 137. The salt was prepared from thorite and from orangite by decomposition with sulphuric acid and recrystallization of the sulphate with the help of heat. The purification was continued until the crystals and the mother liquor had exactly the same composition. Marignac assisted at this investigation. (Liebig's Ann., 131, 1864, 100.) P. T. CLEVE: 233.88 (O- 16). Cleve made six analyses of the anhydrous sulphate, getting in mean Th = 233.8; extreme difference, 1.36. From 122 ATOMIC WEIGHT DETERMINATIONS. analyses of the oxalate he got 233.97; extreme difference, 0.6. (Kopp's Jahresbericht, 1874, 261; Bull. Soc. Chim., (2,) 21, 116.) TIN. Regnault and Kopp have each determined the specific heat of tin. It agrees with an atomic weight of about 118. Dumas, Cahours and others have determined the vapor density of volatile tin compounds with a similar result. (Gmelin-Kraut, 1. c.; L. Meyer, 1. c.) J. J. BERZELIUS; 117.647 (O 16); 735.294 (O - 100). Berzelius determined this value by oxidizing pure tin foil by means of nitric acid and weighing the oxide. I-He found 100 tin = 127.2 stannic acid. (Poqgend. Ann., 8, 1826, 184.) G. J. MULDER: 116.112 (O = 16); 725.7 (O = 100). Two experiments were made by oxidizing tin with nitric acid, evaporating, drying, and heating to redness. They gave each 100 tin = 127.56 stannic acid; whence the value. All possible precautions are said to have been taken. The metal was prepared by the reduction of pure oxide with soot and a flux. (Erdmann's Journ. fiir Prak. Chem., 48, 1849, 35; Scheikundige Onderzoek., 5. Deel, 260.) C. L. VLAANDEREN: about 118. (O = 16). Determined from experiments on the oxidation and reduction of tin and stannic acid in vessels of various materials. The experiments regarded as the most accurate were made on the reduction of the acid in a current of hydrogen in porcelain vessels. The acid had been heated in platinum. These experiments gave 59.04 and 59.12. Stannic acid heated in glass or porcelain was found to retain nitric acid. (Kopp's Jahresbericht, 11, 1858, 138; Mlulder, Scheikundige Verh. en Onderzoek., 2. Deel, 150.) J. DUMAS: 118.08 (O-=16). Two experiments were made on the oxidation of pure tin by nitric acid. The stannic acid being heated white TITANIUM. 123 hot in platinum vessels gave for the atomic weight 59.1 and 58.96. The tin employed was prepared from pure chloride. Two experiments on the titration of the chloride with argentic nitrate gave 59.06 and 59.03. Ag = 108, Cl = 35.5. (Annal. de Chim. et de Phys., (3,) 55, 1859, 156.) TITANIUM. The specific heat of titanic acid has been determined by Regnault and by Kopp, and indicates an atomic weight of about 50. Dumas determined the vapor density of the tetrachloride at 6.836. [If the molecular weight of O = 32, and if Cl = 35.457, this gives Ti = 56.025.] (GmelinKraut, 1. c., and Poggend. Ann., 9, 1827, 441.) H. RosE: 61.17 (O - 16). Determined by roasting titanium sulphide and weighing the titanic acid formed. The'highest result obtained was 1.017 sulphide from 0.757 acid. This result Rose adopted onil the supposition that an excess was impossible. For S - 201.16 these data give Ti = 62.25 (0 16); 389.1 (O - 100.) [If S = 32, Ti = 61.17.] The sulphide was prepared by heating titanic acid in a current of carbon disulphide. (Gilbert's Ann., 73, 1823, 135.) Rose subsequently expressed the opinion that the sulphide employed in this analysis was impure, and contained undecomposed titanic acid, but afterwards came to the conclusion that it was perfectly pure, accounting for the variation of the results from those he obtained later by the theory that the sulphide and the oxide of this element, like those of tantalium, were entirely dissimilar compounds. Marignac has shown that tantalium sulphide is of normal constitution. (Poggend. Ann., 99, 1856, 576.) IH. ROSE: 48.28 (O = 16). Titanium chloride was decomposed with water, titanic acid precipitated by ammonic hydrate, and the chlorine precipitated from the filtrate with argentic nitrate. Taking Ag = 1351.607, Cl = 221.325; Rose calculated the chlorine contents in four experiments at from 74.43 to 74.53 per 124 ATOMIC WEIGHT. DETERMINATIONS. cent; mean 74.46 and Ti at 303.686. According to GmelinKraut, these analyses recalculated for Stas's values give Ti = 48.28. The chloride was prepared by the action of chlorine on a mixture of titanic acid and carbon, and was rectified four or five times over potassium and mercury. It was clear and developed no chlorine on decomposition with water. (Poggend. Ann., 15, 1829, 145.) C. G. MOSANDER: 47.33 (0 = 16); 295.81 (O -= 100). Mosander determined the oxygen contents of titanic acid at from 39.83 to 40.82 per cent.; mean 40.427. Mosander never described the method of analysis. [The oxygen contents was probably determined from the chloride, for the above data give Ti = 294.7, while Berzelius records the determination as having given 295.81.] (Poggend. Ann., 19, 1830, 212, and Berzelius' Lehrbuch, 3, 1211.) J. PIERRE: 50.36 (O- = 16). Determined by three experiments on the titration of the chloride with argentic nitrate by Pelouze's method. Pierre does not give the values taken for C1 and Ag. He calculates the atomic weight of Ti at 314.69. [If Ag = 107.93, Cl = 35.457; his data give Ti = 314.75 (O = 100); 50.36 (O = 16), with an extreme difference in the latter case of 0.08.] He made two other determinations giving lower results, but it was found that the chloride employed was slightly decomposed by contact with air. The chloride was prepared from artificial titanic acid which was free from iron, and was further purified by fractional distillation. (Annal. de Chinz. et de Phys., (3,) 20, 1847, 257.) A. DEMOLY: 56.512 (O = 16). Determined by experiments on the tetrachloride. The salt was decomposed with water, the titanic acid precipitated by ammonic hydrate, and the chlorine precipitated in the filtrate, after the excess of ammonic hydrate had been volatilized and the solution acidified. Both precipitates were weighed. Demoly calculates the atomic weight of Ti at 350, without mentioning what values he accepted for silver and chlorine. [If Ag - 107.93, C1 = 35.457; the atomic weight, calculated from the argentic chloride, is 353.2 (O = 100); or 56.512 (O = 16), with an extreme difference in the three experiments of 0.88 for 0- 16.] The chloride was prepared from rutile by preliminary conver TUNGSTEN. 125 sion into nitride, &c. It was purified by rectification over mercury and potassium. (LiebZq's Ann., 72, 213; Laurent and Gerhardt, Comptes Rend., 1849, 325.) TUNGSTEN. Regnault has determined the specific heat of tungsten, and Roscoe the vapor density of the chloride. These experiments place the atomic weight of tungsten at about 184. (Gmelin-Kraut, 1. c.; L. Meyer, 1. c.) J. J. BERZELIUS: 189.26 (O = 16); 1183.355 (O 100).' A weighed quantity of tungstic acid was reduced in a current of hydrogen, again weighed, then re-oxidized and reweighed. The number is the mean result of the two operations. The number is given in Berzelius' Lehrbuch as 1188.36 with the data, which are also given in Poggend. Ann., 8, 23. It is pointed out in Graham-Otto that this value must be misprinted, an observation which I have verified. (Poggend. Ann., 4, 1825, 152.) Berzelius made an earlier determination than the foregoing by the oxidation of the sulphide, getting 1207. He points out the source of error in this experiment arising from the formation of irreducible sulphate. (Berzelius' Jah.resbericht, 5, 1825, 121.) R. SCHNEIDER: 184.12 (O = 16); 1150.78 (O =100). Schneider made five experiments on the reduction of tungstic acid with hydrogen in a porcelain tube heated by a charcoal fire. These analyses gave the mean contents of the acid at 79.316 tungsten per hundred; extreme difference, 0.096. This composition corresponds to an atomic weight of 1150.89. He also made three experiments on the combustion of tungsten, getting a mean of 79.327 tungsten per 100 acid; extreme difference, 0.005, or an atomic weight of 1151.17. The value taken is the mean. The tungstic acid was prepared by decomposing ammoniotungstic sulphide with chlorhydric acid, washing the precipitate with acid, solution in ammonia, reprecipitation with chlorhydric acid, and so on until a perfectly pure product was obtained. The tungstic acid was finally dried and 126 ATOMIC WEIGHT DETERMINATIONS. heated to redness. (Erdmann's Journ. fiir Prak. Chemn., 50, 1850, 163.) R. F. MARCHAND: 184.1 (O = 16); 1150.6 (O = 100). Determined from two experiments on the reduction of tungstic acid in a current of hydrogen, and two experiments on the combustion of tungsten. These determinations were made in the same manner as and at the same time with Schneider's. The extreme difference was 3.5 for O - 100. (Liebig's'Ann., 77, 1851, 263.) J. B. VON BORCK: 183.816 (O - 16); 1148.85 (O = 100). Determined by seven experiments on the reduction of tungstic acid at a white heat by hydrogen, and by two experiments on the combustion of tungsten. The number is the mean; extreme difference, 10.38 for O - 100. The tungstic acid was prepared from Wolframite by fusing the mineral with potassium carbonate, solution in water containing alcohol, precipitation with calcic chloride and decomposition of the calcic tungstate with chlorhydric acid. The tungstic acid so produced was converted into ammonium salt which, on decomposition, yields a compound free from iron and manganese. (Erdmann's Journ. fiur Prak. Chem., 54, 1851, 254.) A. RICHE: 174 (O = 16). This value was reached by five determinations of the amount of water produced by the reduction of tungstic acid in a current of hydrogen, which gave a mean of 87.07; extreme difference, 1.78. The tungstic acid was obtained by heating the ammonium salt, or by the decomposition of the oxychloride produced by heating tungstic acid and carbon in a current of chlorine. (Annal. de Chim. et de Phys., (3,) 50, 1857, 10.) J. DUMAS: 184 (O = 16). Dumas made six experiments on the reduction of tungstic acid in hydrogen at a high temperature in a nacelle of unglazed porcelain, and two experiments on the titration of the chloride with argentic nitrate. The extreme difference between the results was 0.69 for O = 8. The acid was pre TUNGSTEN. 127 pared by gently heating the ammonium salt in a muffle. (Annal. de Chim. et de Phys., (3,) 55, 1859, 144.) F. A. BERNOULLI: 186.8 (O = 16); 1167.5 (O = 100). Bernoulli made five experiments on the reduction of tungstic acid by hydrogen in a porcelain tube at a very high temperature, two experiments on the amount of water formed in reduction, and four experiments on the oxidation of tungsten. The mean result was W- = 93.41; extreme difference, 0.75. [If experiment 9, in which oxidation seems to have taken place, is left out, the mean becomes 93.35; extreme difference, 0.18.] The tungstic acid was prepared from ammonium tungstate which had been boiled for several days with nitric acid. The tungstic acid was heated to redness. One part of it was green, another part yellow. The determinations from the different colored acids did not differ, and Bernoulli considers them isomeric modifications of the same compound. There appear to be misprints in the data given. (Poggend. Ann., 111, 1860, 599.) C. SCHEIBLER: 184 (O- 16). Scheibler reached this value by five determinations of the water contents (9 molecules) of barium metatungstate. From determinations of the barium and the tungsten in the same compound Scheibler reached other values, but he regards the water determination as the most trustworthy. (Erdmann's Journ. fiir Prak. Chem., 83, 1861, 328.) E. ZETTNOW: 183.952 (O = 16). Determined from analyses of ferrous tungstate and argentic tungstate. A known weight of ferrous tungstate was melted with sodium carbonate and the mass dissolved. The ferric hydrate was thoroughly washed, dissolved in chlorhydric acid, reduced to ferrous chloride with zinc of known composition, and titrated with potassic permanganate in several measured portions. Four such series of experiments were made, and gave a mean of 92.038 for W; extreme difference, 0.33. The ferrous tungstate was prepared by melting pure anhydrous sodium tungstate with ferrous chloride and sodium chloride, dissolving, separating impurities, crystallizing, washing the crystals with water, chlorhydric acid and sodium carbonate. The argen 128 ATOMIC WEIGHT DETERMINATIONS. tic tungstate was decomposed with nitric acid and titrated with sodium chloride or decomposed with hot sodium chloride solution, the argentic chloride being weighed. Five experiments gave a mean of 91.915 for W; extreme difference, 0.13. The argentic tungstate was prepared by the precipitation of sodium tungstate with argentic nitrate, thorough washing and drying in yellow light. The permanganate solution was prepared according to MIohr and tested with ammonio-ferrous sulphate. Fe = 28, Ag - 108. (Poggend. Ann., 130, 1867, 30.) H. E. ROSCOE: 184.04 (O = 16). Determined by reducing tungstic acid in a current of hydrogen, by reoxidizing the metal, and by reducing the chloride in a current of hydrogen, the chlorhydric acid being condensed and estimated as argentic chloride. Ill the experiments on the acid, that compound was reduced, and reoxidized three times with almost identical results. The mean of the second and third reductions of the same sample gave W = 183.84. In the experiments on the chloride, the chlorine and the tungsten were each determined, and gave a mean of 184.25 for Cl = 35.5.. The tungstic acid was prepared by the decomposition of the chloride, washing and heating to redness in a platinum vessel. It was canary yellow. The chloride was prepared from pure tungsten. (Liebig's Ann., 162, 1872, 366.) URANIUM. No certainty exists as to the relation between the equivalent and the atomic weight of uranium. The latter is commonly accepted as about 120. Mendelejeff gives grounds for supposing it to be 240, (Liebig's Ann., S. 8, 1871, 178,) and L. Meyer regards it as probably 180, a value which accords well with the specific heat of the black oxide as observed by Regnault. (Gmelin-Kraut, 1. c.) For the purposes of this paper it seems best to retain the customary value. J. A. ARFVEDSON: 128.6 (O =- 16). Determined by experiments on the reduction of uranoso URANIUM. 129 uranic oxide and on the oxidation of uranous oxide. By combustion of uranous oxide in oxygen he found in two experiments that 100 oxide combined with 3.695 and with 3.73 oxygen. From the reduction of the green oxide he found that 100 uranous oxide combine with 3.67 oxygen. Ite deduces as the mean 3.688. Regarding uranous oxide as the metal, Arfvedson calculated the atomic weight at 2711.36. [If the lower oxide is a protoxide, the data give 128.6 for O0- 16.] The uranous oxide was prepared from pitchblende by solution in aqua regia, precipitation of heavy metals with hydrogen sulphide, precipitation with ammonia hydrate, solution in ammonium carbonate to remove iron, reprecipitation, heating to redness, washing with chlorydric acid to remove impurities, and reduction in hydrogen. (Poggend. Ann., 1, 1824, 254.) E. PELIGOT: 119.128 (O - 16). In two experiments the amount of carbon in the acetate was found to be 11.27 and 11.3; mean 11.285. In one experiment the uranic oxide was determined at 67.3 per cent. [From these data the above value follows.] Peligot takes 120 or 750, C = 75. The preparation of the salt is not given. Peligot mentions the oxalate and gives analyses, but does not deduce an atomic weight from them. (Annal. de Chim. et de Phys., (3,) 5, 1842, 39.) J. J. EBELMEN: 118.86 (O- 16); 742.875 (O= 100). Ebelmen made six experiments on the reduction of the oxalate to uranous oxide by hydrogen and heat. The value follows with an extreme difference of 0.65 for C = 75; H -- 12.5. All the weighings were reduced to vacuum. To obtain pure oxalate, the nitrate was precipitated by oxalic acid and this preparation decomposed by heat. The oxide thus obtained was digested with chlorhydric acid, washed, dissolved in nitric acid, recrystallized, and precipitated with oxalic acid. The oxalate was dried at 100~. According to Ramrnelsberg the reduction of the oxalate is accornpanied by the separation of carbon which remains with the oxide. (Annal. de Chim. et de Phys., (3,) 5, 1842, 189.) BERZELIUS, ARFVEDSON, MARCHAND: 128.4 (O = 16); 802.49 (O = 100). While Arfvedson was making his first determination, Berzelius also made an experiment on the combustion of ura9 130 ATOMIC WEIGHT DETERMINATIONS. nous oxide getting 103.685 uranic from 100 uranous oxide. Marchand (Erdmann's Journ. fiir Prak. Clhem., 23, 1841, 498) got in the same way 103.668. The average of the combustion experiments of all three chemists is 103.694, whence Berzelius calculates the value. (Berzelius' Jahresbericht, 22, 1842, 113.) Peligot and Rammelsberg, as well as Marchand, point out faults in this method, such as the probable condensation of hydrogen in the protoxide and the tendency to form higher oxides. (Poggend. Ann., 59, 1843, 4.) C. RAMMELSBERG. This chemist made experiments on the reduction by hydrogen of the green oxide, prepared in various ways, and got results varying from 580.4 to 767.6 for O = 100. (Poggend. Ann., 59, 1843, 9.) By precipitation of uranous chloride with silver he reached the number 787.5 for Cl - 442.65. The chlorine contents found varies in three experiments from 73.89 to 74.46. The chloride was prepared by heating uranous oxide in an atmosphere of chlorine. (Poggend. Ann., 55, 1842, 321.) J. WERTHEIM: 119.42 (0 = 16); 746.36 (O = 100). Determined by three experiments on the decomposition of the double acetate of uranium and sodium. The mean loss of acetic acid by heating the salt to redness was 32.477 per cent.; extreme difference, 0.036. The number follows for C = 75, H = 6.25, Na - 390.9. [In Poggend. Ann., 57, 484, an abstract is given of a paper read before the academy (of Berlin?) by Mitscherlich, in which he states that Wertheim's experiments above described give 740.512. Berzelius in his Jahresbericht, 23, 137, makes or quotes the same statement, so also does Rammelsberg, Poggend. Ann., 59, 4, and it has been repeated elsewhere. I have recalculated the data given by Wertheim and find the results correctly deduced in his own report. For Na = 23.043 (Stas); the data give U = 119.53.] The salt was prepared from uraninite by solution in nitric acid, precipitation with hydrogen sulphide, evaporation of the filtrate to dryness, solution in hot water, crystallization and recrystallization, heating the crystals to drive off nitric acid, solution in acetic acid, digestion with sodium carbonate and recrystallization. (Erdmann's Journ. fur Prak. Chem., 29, 1843, 209.) VANADIUM. 131 C. RAMMELSBERG: about 120 (O- = 16). Determined in six experiments, undertaken at Berzelius' suggestion, by treating uranous oxide with nitric acid and sulphuric acid and weighing the sulphate. It is very difficult to weigh the uranous oxide which constantly increases in weight. Two experiments were made on the green oxide, which was prepared either by heating uranous oxide, or the nitrate, in air. Two experiments were made on magnesium uraniate by dissolving the compound in nitric acid and heating to redness. The compound was found unstable in character. One experiment was made by heating the double acetate of uranium and sodium and three experiments by heating the double acetate of barium and uranium. The results obtained varied from 633.17 to 753.76. Rammelsberg considers the determinations confirmatory of Wertheim's and Ebelmen's. (Poggend. Ann., 66, 1845, 95.) E. PELIGOT: 120 (O = 16); 750 (O =- 100). Determined by combustion of the oxalate in a current of air, both the carbonic acid and the green oxide of uranium being weighed. At first Peligot got only 730 as the atomic weight by this process, but by repeating the recrystallization of the salt until determinations gave constant results, he got a mean of 750. IHe says that he came to the same value by comparing the amount of uranic oxide obtained front the acetate with the weight of the salt employed. (Paris Comptes Rend., 22, 1846, 487.) VANADIUM. Roscoe has determined the vapor density of vanadium chloride. It agrees with an atomic weight of about 51. (L. Meyer, 1. c.) J. J. BERZELIUS: 52.47 (O = 16). Berzelius made four experiments on the relation between the higher and the lower oxides of vanadium, three by reduction with hydrogen at a very high temperature and one by oxidation. He supposed the higher oxide to have the formula V03, and the lower VO, and consequently. got for 132 ATOMIC WEIGHT DETERMINATIONS. the atomic weight the number 855.84 (O = 100). R. Schneider has shown that the data as given by Berzelius are discordant, (Poggend. Ann., 88, 319,) a fact of small importance in view of the succeeding investigation. The higher oxide analyzed by Berzelius was produced by gently heating the ammonium salt. (Poggend. Ann., 22, 1831, 14; Korygl. Vet. Akad. Handl., 1831.) Roscoe examined some ammonium vanadate which Berzelius had sent Faraday and found that it contained phosphorus. (Liebig's Ann., S, 6, 1868, 93.) H. E. RoscoE: 51.33 (O = 16). Roscoe made four experiments on the reduction of vanadic acid (V2 05) in carefully purified hydrogen. The acid was prepared from ammonium vanadate. To free this compound from phosphorus and silicic acid it was powdered, decrepitated with sodium in an iron crucible, washed with water and with chlorhydric acid, re-oxidized with nitric acid, chloridized in a current of chlorine, the chloride rectified and decomposed with water. The acid so obtained was dried, moistened with sulphuric acid, exposed to the fumes of fluohydric acid for ten days and melted. This pure acid was first heated for several hours in dry air and afterwards in hydrogen. The mean result of four experiments was V = 51.371; extreme difference, 0.228. Nine experiments were made on the titration of the chloride by Pelouze's method. Eight experiments were also made on the analysis of the chloride with argentic nitrate by the ordinary method. The mean of the seventeen experiments on the chloride gives the contents in chlorine at 61.276 per cent.; extreme difference, 0.69. This composition indicates an atomic weight of 51.29. Roscoe takes Cl = 35.457, Ag = 107.93. The vanadium chloride was purified by rectification over sodium in a current of carbon di-oxide. The reagents were prepared according to Stas. (Liebig's Ann., S, 6, 1868, 86.) Roscoe mentions atomic weight determinations by Czudnowicz as giving 55.35. This chemist, however, did not calculate an atomic weight from his analyses, but used that obtained by Berzelius. (Poggend. Ann., 120, 1863, 17.) YTTRIUM. 133 YTTRIUM. The composition of yttrium oxide is not definitely settled. Mendelejeff concludes from the general behavior of its compounds that it is a sesqui-oxide. As, however, all the chemists who have made atomic weight determinations of this element have considered it a prot-oxide, I shall assume it to be so and the atomic weight, therefore, about 60. J. J. BERZELIUS: 64.29 (O = 16); 401.84 (O = 100). This determination was made before the discovery of erbium and can scarcely be correct. The value was reached by analysis of the sulphate with barium chloride. Ba- 856.88, S = 201.165. (Poggend. Ann., 8, 1826, 186; 10, 1827, 341.) N. J. BERLIN: 59.7 (O = 16). According to Blomstrand in Berlin, Ber. der Chem. Ges., 1873, 1467. I can find no other record of this determination which probably appeared in the Forhandl. ved de Skandinaviske Naturforsk, 1860, 448. O. PoPP: 68 (O = 16), The mean of four analyses of the sulphate showed that 40.15 oxide were equivalent to 38.23 sulphuric anhydride, giving a molecular weight for the oxide of 42.015;'extreme difference, 0.013. The yttrium was precipitated with sublimed oxalic acid, the free acid being afterwards neutralized with ammonia. The sulphuric acid was precipitated with barium chloride in the filtrate with precautions. Popp, who denies the existence of erbium and terbium, separated yttriumrn from the cerite oxides by precipitation with barium carbonate, yttrium remaining in solution, S = 16, Ba 68.5. (Liebig's Ann., 131, 1864, 183.) M. DELAFONTAINE: about 64 (O = 16). Delafontaine does not pretend that this number is exact. It is derived from analyses of the sulphate. His method of separation was essentially Mosander's, which was proved by Popp and by Bunsen and Bahr to give impure salts. (Liebig's Ann., 134, 1865, 108.) 134 ATOMIC WEIGHT DETERMINATIONS. BAHR AND BUNSEN: 61.7 (O = 16). Determined by saturating the oxide with sulphuric acid as in the determination of erbium, q. v. Partial recrystallization does not produce pure yttrium nitrate, but only concentrates traces of didymium in the salt. Didymium must be separated with potassic sulphate. Erbium nitrate is more easily decomposed by heat than yttrium nitrate. The nitrates were therefore partially decomposed, yttrium nitrate dissolved out and the process repeated until there was no trace of erbium or didymium visible in the spectroscope. The mean of two determinations gave Y = 30.85; difference, 0.1. S - 16. (Liebig's Ann., 137, 1866, 21.) M. DELAFONTAINE: 58.5 (O = 16). Determined by three experiments on the sulphate which gave in mean 48.23 per cent. oxide for S = 32. [In the Jahresbericht this determination is reported as giving Y = 74.5. Yttrium is apparently a misprint for yttrium oxide.] The yttrium salt seems to have been prepared according to the method of Bahr and Bunsen. (Kopp's Jahresbericht, 1866, 184; Bibl. Univ., Arch. des Sciences, (2), 25, 1866, 112.) P. T. CLEVE AND 0. M. HOEGLUND: 59.7 (O = 16). Determined by analysis of the sulphate. The oxide was purified by heating the nitrates, etc., according to N. J. Berlin. (Blomstrand, in Berlin, Bericht der C(hem. Ges., 1873, 1467; Bihang till Vet. Akad. ilandl, 1873, B. 1, 3, No. 8.) ZINC. The specific heat of zinc has been determined by Regnault and others. The vapor density of volatile organic compounds has been determined by Frankland and others. These experiments agree in placing the atomic weight at about 65. (Gmelin-Kraut, 1. c.; L. Meyer, 1. c.) GAY-LUSSAC, BERZELIUS, WOLLASTON: 65.547 (O 16); 409.67 (O = 100). In his experiments on the oxidation of zinc Gay-Lussac ZINC. 135 found that 100 Zn = 24.41 oxygen. This value is repeatedly cited in his memoir. (Gilbert's Ann., 30, 1811, 297; Memoire D'Arceuil, 2, 174.) Wollaston gives the same figures on Gay-Lussac's authority. (Phil. iTrans., 104, 1814, 21.) Wollaston calculates from these data Zn = 410, (O - 100.) Berzelius in each of two experiments got 100 Zu - 124.4 oxide. (Gilbert's Ann., 37, 1811, 460.) In Poggend. Ann., 8, 1826, 184, as well as in his Lehrbuch, Berzelius cites Gay-Lussac as having found 100 Zn = 24.8 oxygen. He states that his own determinations were in perfect accordance with these figures, and calculates from them the atomic weight of zinc at 403.226 or 64.52, and this was the accepted value for many years. I cannot find any other determinations by either of these chemists, and am obliged to suppose that there was a mistake made in recording the data from which Berzelius made his calculations; if so, it is remarkable that neither Berzelius nor the other chemists who determined this value perceived it; for the question was reopened during Berzelius' life, and A. Erdmann made his determination at Berzelius' request. V. A. JACQUELIN: 66.24 (O = 16); 414 (O = 100). This number was reached by measuring the amount of hydrogen developed by a known weight of zinc from sulphuric acid on the supposition that the specific gravity of hydrogen is 0.0624. The results seem to have been inconsistent. Subsequently Jacquelain arrived at the same number by oxidizing an impure zinc of known composition. (Paris Comptes Rend., 14, 1842, 636; and Annal. de Chim. et de Phys., (3,) 7, 1843, 204.) P. A. FAVRE: 66, (O = 16); 412.5 (O-= 100). Favre made four experiments on the combustion of zinc oxalate, the carbon di-oxide being collected and its weight compared with that of the oxide. The mean result was Zn = 412.66; extreme difference, 1.11. C - 75. He also made three experiments by passing the hydrogen developed by a known weight of zinc over cupric oxide, the water being caught. These experiments gave in mean Zn = 412.16; extreme difference, 0.65 for TI = 12.5. (Annal. de Chim. et de Phys., (3), 10, 1844, 163.) A. ERDMANN; 65.05 (O = 16); 406.591 (O - 100). Determined by oxidizing pure zinc with nitric acid, and 136 ATOMIC WEIGHT DETERMINATIONS. driving off the acid by heating the salt in a porcelain crucible. Platinum is attacked. The number is the mean of four'experiments; extreme difference, 0.698. The zinc was prepared by mixing pure oxide with carbon, and distilling in a current of hydrogen. (Berzelius' Jahresbericht, 24, 1844, 132; (Efversigt af Kongl. Vet. Akad. Ilandl., 1, 3.) ZIRCONIUM. Deville and Troost have determined the vapor density of the chloride. It agrees with an atomic weight of about 90. (L. Meyer, 1. c.) J. J. BERZELIUS: 89.6 (O - 16). In one experiment the sulphate was decomposed with ammonic hydrate, the oxide weighed and the sulphuric acid precipitated with barium chloride. In five experiments the sulphate was decomposed at a white heat, amrnonium carbonate being added at the close of the operation. The mean result was that 100 parts of sulphuric anhydride unite with 75.853 parts of zirconium oxide; extreme difference, 0.23. Berzelius deduces the value 840.08 for 0 O 100, S- 201.165; on the supposition that the oxide contains three atoms of oxygen. [Being a binoxide, this relation gives Zr = 89.6 for O 16.] The sulphate seems to have been prepared by dissolving the oxide in sulphuric acid and expelling the excess of acid by heat. (Poggend. Ann., 4, 1825, 126.) R. HERMANN: This chemist made some experiments on the chloride getting in three determinations a mean of 839.45 for O = 100 and on the tri-oxide supposition. The extreme difference was 20.1. Cl = 443.65. The chloride was produced by heating the oxide with carbon in a current of chlorine. Hermann adopts not his own but Berzelius' determination. (Erdmann's Journ. fiir Prak. Chem., 31, 1844, 77.) C. MARIGNAC: 90 (O = 16). Determined from analyses of potassium fluo-zirconiate. The salt was decomposed with sulphuric acid, the excess ZIRCONIUM. 137 of acid driven off by heat, the residue weighed, the potassic sulphate leached out with water, and the residue again weighed. Marignac does not pretend that the'determination is accurate. The results gave from 45.01 to 45.48. He thinks that some potassic sulphate may have escaped solution, and therefore takes the minimum. K = 39, S - 16. According to Marignac, Deville also found the atomic weight of zirconium somewhat higher than Berzelius by analysis of the chloride with which he determined the vapor density. (Annal. de Chim. et de Phys., (3,) 60, 1860, 257.) APPENDIX. DETERMINATIONS BY T. THOMSON. In Thomson's Annals of Philosophy, volumes 16 and 17, 1820-21, Thomson published a series of papers descriptive of experiments undertaken for the purpose of verifying Prout's hypothesis. His method consisted in mixing reagents in what he considered equivalent proportions, and after precipitation examining portions of the supernatant liquidt for an excess of each of the salts supposed to neutralize one another. In all except four cases, either the salt analyzed was a sulphate and the precipitant barium chloride, or the determination was dependent upon such an analysis; yet although Thomson took barium = 70, in no instance was he able to detect either barium or sulphuric acid in the residual solution when the quantity of the re-agents corresponded to the atomic weights which he adopts. Comparison of his results with those reached by more accurate experimenters will make this exact neutralization appear impossible, nor were his contemporaries able to repeat his experiments successfully. Thomson's determinations are, as such, utterly valueless, yet as they were for many years extensively accepted in English and American scientific literature they are inserted here for reference. In the following table Thomson's numbers are multiplied, when necessary, for the sake of comparison with the values now accepted. DETERMINATIONS INVOLVING BARIUM -- 70. Arsenic -____ __ _ 76 Magnesium ___ _-__ 24 Barium -- -- _______ 140 Manganese — _______ 56 Bismuth __216 Nickel _52 Calcium ----- --- - _____40 Nitrogen ___-___-__ 14 Carbon.._. __ 12 Phosphorus___ _.____32 Chlorine _ _. 36 Potassium _________-. A40 Chromium --- ------— 56 Silver _-_-______-__ 110 Cobalt___ 52 Sodium -24 Copper_ -___ _ -.__ 64 Strontium _ —--------- - 88 Iron _-_ _-___ —- — 56 Sulphur __32 Lead -- -- 208 Zinc..68 139 140 ATOMIC WEIGHT DETERMINATIONS. THOMSON FURTHER DETERMINEDAntimony at 132 by oxidation. Boron at 12 from analysis of borax. Mercury at 200 by conversion of the oxide into chloride. Tin at 116 by oxidation with nitric acid. REDUCTION OF WEIGHINGS TO VACUUM. In discussing the analyses recorded in the foregoing pages, or in reconciling atomic weight determinations by various chemists, it may be found convenient to employ the following table. The maximum error involved is less than 0.01 per cent. or 0.1 milligram per gram. GRAM WEIGHTS BEING OF BRASS, FRACTIONS OF PLATINUM. For substances the sp. gr. of which exceeds 6.1; no correction is necessary. For substances the sp. gr. of which is less than 6.1:To correct the entire grams; multiply their number by the correction in the table opposite the sp. gr. of the substance, found in the first column, and add the product to the observed weight. lo correct the fractions of a gram, multiply the correction opposite the sp. gr. of the substance, found in the third column of the table, by the first two decimal figures of the observed weight, if the sp. gr. of the substance is less than 3, and by the first decimal only, if the sp. gr. exceeds 3, and add the product to the observed weight. ALL WEIGHTS USED BEING OF PLATINUM. For substances the sp. gr. of which exceeds 7.8, no correction is necessary. For substances the sp. gr. of which is less than 7.8:Multiply the correction opposite the sp. gr. of the substance, found in the third column, by the number of grams, tenths and hundredths observed, if the sp. gr. falls short of 3, or by the number of grams and tenths, if the sp. gr. exceeds 3, and add the product to the observed weight. The table shows within what limits it is necessary to know the sp. gr. APPENDIX. 141 ( Weights of Brass) for Correction per Gram lVeights of Platinum) for Specific Gravity between- Error < I Mg.,Specific Gravity between27.738 and 11.064 — 0.000 067 gram 11.064 6.904 0.000 000 51.766 and 13.568 6.904 5.019 +0.000 067 13.568 7.807 5.019 3.943 0.00)0 133 7.807 5.480 3 943 3.247 0 000 200 5.480 4.222 3,247 2.759 0.000 267 4.222 3 433 2.759 2 399 0 000 333 3.433 2.893 2.399 2.122 0.000 400 2.893 2.500 2.122 1.903 0.000 467 2.500 2.201 1.903 1.724 0.0 00 533 2. 01.1.965 1.724 1.576 0.000 600 1.965 1.776 1.576 1.452 0.000 667 1.776 1.619 1.452 1 377 0.000 733 1.619 1.488 1.377 1.254 0000) 800 1.488 1.377 1.254 1.174 0.000 867 1.377 1.281 1 174 1.103 0.000 933 1.281'1.197 1.103 1.041 0.001 000 1.197 1.124 1.041 0.985 0.001 067 1.124 1.059 0.001 133 1.059 1.002 0.001 200 1.002 0.950 (Sill. Amer. Jour., 16, 1878, 265; Liebig's Ann., 195, 1879, 222.) INDEX TO AUTHORITIES. Acta Universitatis Lundensis, 90. Afhandlingar i 1Fysik, etc., 79. Annales de Chimie et de Physique, 8, 10, 12, 13, 15, 19, 20, 21, 22, 24, 28, 30, 35, 40, 41, 42, 43, 47, 50, 51, 55, 56, 61, 62, 63, 65, 66, 67, 71, 72, 73, 74, 77, 78, 79, 81, 84, 86, 87, 88, 93, 97, 100, 102, 104, 106, 109, 111, 113, 115, 118, 119, 123, 124, 126, 127, 129, 135, 137. Berlin, Bericht der Deutschen Chemischen Gesellschaft, 18, 48, 49, 54, 59, 89, 105, 134. Berzelius' Lehrbuch der Chemie, 7, 12, 14, 17, 18, 22, 23, 26, 27,28, 29, 38, 46, 49, 54, 56, 71, 74, 76, 80, 82, 83, 86, 98, 105, 112, 114, 116, 120, 121, 124. Berzelius' Jahresbericht iiber die Fortschritte der Chemie, etc., 8, 41, 56, 62, 65, 66, 74, 78, 79, 80, 86, 92, 93, 100, 108, 114, 115, 125, 130, 136. Bibliotheque Universelle de Geneve, Archives des Sciences, 15, 16, 22, 27, 32, 41, 46, 47, 62, 72, 84, 87, 88, 91, 93, 100, 108. 113, 134. Bihang till Vetenskaps Akademien Handlingar, 134. (See Kongliga Vetenskaps Akademien.) British Association Reports, 15, 19. Bulletin de la Soeiet6 Chimique, 53, 54, 122. Bulletin de l'Acad6mie Royale des Sciences, etc., de Belgique, 32, 33. Chemical News, 25, 48, 65, 89. Edinburgh Royal Society Transactions, 56, 80. Erdmann's Journal fuir Praktische Chemie, 18, 23, 24, 27, 28, 29, 31, 35, 37, 44, 45, 48, 49: 52, 55, 58, 59, 60, 62, 67, 68, 69, 76, 77, 78, 79, 81, 83, 86, 88, 90, 92, 94, 96, 102, 104, 114, 117, 119, 122, 126, 127, 130, 136. Fresenius' Zeitschrift fuir Analytische Chemie, 48, 50, 52, 89. Forhandlinger ved de Skandinaviske Naturforskeres, 133. Gilbert's Annalen der Physik, etc., 96, 123, 185. Gnmelin-Kraut, Handbuch der Chemie, 7, 9, 12, 13, 18, 19, 20, 21, 23, 26, 37, 43, 46, 49, 56, 62, 64, 65, 68, 73, 76, 79, 81, 83, 86, 90, 91, 94, 95, 96, 98, 101, 102, 103, 106, 110, 111, 113, 117, 118, 122, 123, 125, 128, 134. Halle, Zeitschrift fur die Gesammten Naturwissenschaften, 45..Jenaische Zeitschrift fur Medicin und Naturwissenschaft, 52. 143 144 INDEX TO AUTHORITIES. Journal de Pharmacie et de Chimie, 94. Journal of the Chemical Society, 47, 88, 97. Klatzo, Ueber die Constitution der Beryllerde, 18. Kongliga Vetenskaps Akademien Handlingar, 21, 83, 94, 95, 101. Kopp's Jahresbericht fiber die Fortschritte der Chemie, 45, 52, 53, 78, 104, 122, 134. Laurent and Gerhardt's Comptes Rendus Mensuels, etc., 125. Liebig's Annalen der Chemie, etc., 15, 26, 28, 29, 30, 31, 32, 35, 36, 37, 40, 41, 43, 51, 52, 53, 54, 68, 73, 75, 78, 86, 91, 93, 99, 103, 106, 107, 115, 116, 117, 120, 121, 125, 126, 128, 132, 133, 134. Meyer, L., Moderne Theorien der Chemie, 7, 9, 12, 20, 28, 81, 113, 122. Mitscherlich's Lehrbuch der Chemie, 30. 4Efversigt af Vetenskaps Akademien Foerhandlingar, 79, 136. (See Kongliga Vetenskaps Akademien.) Otto's German Translation of Graham's Chemistry, 33, 34, 67. Paris Comptes Rendus, 8, 13, 15, 20, 26, 40, 42, 50, 55, 56, 58, 75, 83, 85, 89, 93, 95, 97, 100, 105, 111, 112, 116, 131, 135. Pelouze, Trait6 de Chimie, 8. Philosophical Magazine, 8, 17, 22, 30. Philosophical Transactions of the Royal Society, 14, 26, 28, 33, 37, 38, 39, 43, 49, 54, 56, 65, 71, 72, 76, 82, 91, 92, 96, 99, 106, 107, 110, 112, 113, 114, 120. Poggendorff's Annalen der Physik, etc., 9, 10, 11, 12, 13, 14, 17, 18, 19, 21, 24, 25, 26, 29, 33, 36, 38, 43, 45, 46, 49, 51, 53, 54, 59, 60, 61, 64, 65, 66, 67, 68, 91, 94, 95, 98, 99, 101, 102, 103, 104, 105, 106, 11(Q 114, 116, 118, 121, 122, 123, 124, 125, 127, 128, 129, 130, 131, 132, 133, 135, 136. Proceedings of the American Academy of Arts and Sciences, 11, 12. Schweigger's Journal fuir Chemie und Physik, 23, 86. Scheikundige Verhandelingen en Onderzoekingen, 122. Silliman's American Journal of Science, 25, 26, 37, 46, 74, 75. Sitzungs-Bericht der k. k. Akademie zu Wien, 48, 81, 88, 97, 104, 118. Stas, Untersuchungen fiber Chemischen Proportionen und Atomgewichte, 23, 43, 59, 62, 64, 73, 76, 94, 98, 101, 110, 111, 115. Stockholm Akademien Handlingar, 18. (See Kongliga Vetenskaps Akademien.) Thomson's System of Chemistry, 7, 14, 17, 20, 23, 24, 29, 61, 73. Thomson's Annals of Philosophy, 58, 61, 139. Thomson, R. D., Records of General Science, 92, 114. Zeitschrift fur Berg Huitten-und Salinen-Wesen im Preussichen Staate, 49, 51. INDEX TO ATOMIC WEIGHT DETERMINATIONS. ALLEN. (JOHNSON and) BERZELIUS, J. J. BORCK, J. B. VON Czesium -...... 25 Chlorine ___. 37, 38 Tungsten _____-126 Aluminium ----------- 7 Clhromium ___- 43 Boron-1_ ______ I9, I40 ANDERSON, T. Copper _._ —____ 49 BRANDES, R. Nitrogen _.. —- 93 Fluorine _____ 54 Manganese o80 ANDREWS, T. Gold __56 BRODIE, B. C. Barium _-__ I5 Iodine __ __ 6I Graphon ___.-. 33 Platinum -_ —--- 98 Iridium __ 641 Phosphorus _ ___ 97 Antimony -_._____ — 9, 140 Iron______- _ 65, 661 Bromine __ ~___ _____ 20 ARAGO. (BIOT and) Lead ________ — 7I BUEHRIG, H. Carbon________- 28 Lithium __ 74 Cerium __- ___ 37 Nitrogen _. —-_ 91 Magnesium __ 76 i BUNSEN, R. W. ARFVEDSON, J. A. Manganese __ 79, 80o Cesiumn._____ 25 Lithium ___-___ 73 Molybdenum ___ 83 Indium 60o Manganese -__ 79 Nickel -_______ 87 BUNSEN, R.W., andJ. JEGEL. Uranium _ I28, I29 Nitrogen __. —_ 91 Cerium __ 35 Arsenic _____- I2 Osmium-_ _ ___ 94 BUNSEN, R. W. (J. F. BAIIR AWDEJEW. Palladium.....__ 95 and) Beryllium _ —--- 17 Phosphorus _ _ 96 Erbium 53 Platinum_______ 98 Yttrium __ 1 _._I134 BAHR, J. F. Potassium ______ 99 BUNSEN. (KIRCHOFF and) Magnesium ___- 78 Rhodium ___- _ Io I CXsium __. — ___ 24 BAHR, J. F., and R. W. Selenium ------ Io4 Rubidium -____IO02 BUNSEN. Silicon_ _.- ___-. Io 5 Erbium. —--—.53 Silver__. __- __IO6 Cadmium.__ 23 Yttrium _ 1_.I34 Sodium esium ___ __ 24 BALARD, A. J. Sulphur....II3 I 4 Calcium______ __- 26, I39 Bromine 20 Tantalium _... I I6 CAPITAINE, H. Barium ____ 13 Tellurium __._ I 18 Iron ______-___ 66 BERINGER, A. Thorium.- 1.. I20 ICarbon_- _____ ___ 28 Ceriumn 34 Tin-22 Cerium 34 BERLIN, N. J. Tungsten_ ____I125 CHENEVIX, R. Chromium n _____ 44 Uranium ___-_ I29 Copper __-_.___ 49 Molybdenum ___ 84 Vanadium _... I31I Chlorine _-____ 37, I39 Thorium - ----- 121 Yttrium -______ 133 CHOUBINE. Yttrium ----— I33 Zinc..-_______. 134 Lanthanium ___ 68 BERNOULLI, F. A. Zirconium ___... I36 Chromium _- __ __. 43 Tungsten _ —-- - 127 CHYDENIUS, J. J. BERTIIIER, P. BERZELIUS and DULONG. Thorium -_ —-- 121 Nickel___-. —-- 86 Hydrogen. —-- 57 CLAUS, C. E. Beryllium I6 Nitrogen -_ 9_ 1 gI Iridium ______- 65 BERZELIUS, J. J. BERZELIUS and LIEBIG. Ruthenium _ __10 Io3 Aluminium _-__ 71 Carbon_ -_-____ 31 CLEVE, P. T. Antimony.. 9 I BIOT and ARAGO. Didymium __-__ 53 Arsenic_____.. I21 Carbon- _.. __. 28 Erbium Barium 14 Nitrogen 91 Lanthanium — _- 70 Beryllium ____- 17 Bismuth-.._.... 18, I39 Thorium. I..- 12I1 Boron.______ I 19 BLOMSTRAND, C. W. CLEVE, P. T., and 0. M. Bromine _ 21I Niobium _-_ 9_0_ go HOEGLAND. Calcium __._ 26, 28 BOISBAUDRAN, L. DE Erbium -_____. 54 Carbon 29 Gallium _ 56 Yttrium ------— 134 10 145 146 INDEX. Cobalt-_ __ — __ 46, I139 DUMAS, J. GAY-LUSSAC, L. J. COMMAILLE. (MILLON and) Magnesium ____ 79 Zinc _ _ _____134 Copper -_..__.. 50 Manganese _ 8I GERHARDT, C. CooKv, J. P., Jr. Molybdenum ___ 84 Chlorine _______ 41 Antimony._____ II Nickel ___ ____ 87 GIBBS, W. Copper _______ 49, I139 Nitrogen_______ 93 Cerium_ -.. —--- 37 CROOKES, W. Phosphorus __- -- 97 Cobalt _-__- ___ 46 Thallium___II9, 120 Potassium _-____ IOO GMELIN, C. G. CZUDNOWICZ, C. Selenium _-__ __ 104 Lithium 73 Lanthanium_____ 69 Silicon....__.105 GMELIN-KRAUT. Sodium __ i _iI I Boron -__ —_-1- I9 DAVY, H. Strontigm 1_____I13 Carbon ___- __- 33 Fluorine _ —---- 54 Sulphur -__-_-__I 15 Iodine ___ ___ 62 Mercury 82 Tellurium. —--- II8 GODEFFROY, R. Silver _ _ _ _____ Io6 Tin__ 1___ _____ I22 COesium _ __ _ _ 25 DAVY, J. Tungsten 1___ 26 Rubidium 10___ Io3 Sodium _-____ I I0O DUMAS and STAS. Gold 56 DEBRAY, HI. Carbon -__- _... 30 Graphon ____-__-__ 33 Molybdenum ___ 84 DEBRAY. (DEVILLE and) EBELMEN, J. J. HAGEN, R. Osmium- ___ __ 94 Uranium _ —.___129 Lithium 74 DELAFONTAINE, M. EINBRODT, P. HAMPE, W. Erbium - - 53 Nitrogen 93 Copper __- __... 50 Molybdenum ___ 84 EKMAN, G. (O. PETTERSSON HAUER, K. VON Thorium -__ ___121 and) Cadmium _-____ 23 Yttrium _ I33, 134 Selenium ____ IO5 Manganese __So80 DEMOLY, A. Erbium _._________ 53 Tellurium ____ II8 Titanium ______I24 ERDMANN, A. HEBBERLING, M. DEVILLE, H. SAINTE-CLAIRE Zinc ___I 35 Thallium _____ I 9 Nickel_ __ — __. 87 ERDMANN and MARCHAND. HENRY, W. DEVILLE and DEBRAY. Calcium.-__.._ 27 Magnesium.___ 76 Osmium __. ___ 94 Carbon __ _3~ HERMANN, R. DEVILLE. (WOEHLER and) Copper ______ 49 Cerium 34 Boron -— ___ 19___ I Hydrogen______ 58 Didymium______ 51 DEXTER, W. P. Iron 66 Lanthanium__ 68, 69 Antimony Io Mercury 82 Lithium 73 Didymnium__._____ 5I Nickel ___-.___.86 Niobium _ go DIEHL, K. Selenium. —-— IO4 Tantalium ____II 17 Lithium -_-_-_- 75 Sulphur _-____ I I14 Zirconium _-___I136 DULONG. (BERZELIUS and) ERIK, C. HILLEBRAND, W. F. Hydrogen __-_ 57 Didymium ____. 52 Didymium 53 Nitrogen _-____ 91I Lanthaniurn ___ 70 IIISINGER, W. DUMAS, J. Cerium -34 Aluminium -.... 8 FAVRE, PI. A. HOEGLUND, 0. M. (P. T. Antimony -_____ Io Zinc I135 CLEVE and) Arsenic __ 12, 13 Fluorine ___ __ 54 Erbium _ 54 Barium I6 FOURCROY and THENARD. Yttrium __-_ 134 Bismuth- 19. _._ I9 Mercury -__ 82 IIOLZMANN, M. Bromine _-___-. 22 FOWNES, G. Lanthanium... 68 Cadmium -_- - - 24 Carbon-..._._._ 30 Hydrogen 57 Calcium_____ 26, 28 FREMY, E. Carbon ___-___. 29 Fluorine _______ 55 Indium ___59 Chlorine _,__- 42 Osmium __.-.._ 94; Iodine _.__________. _ 6I Cobalt 47 FREMY. (PEIOUZE and) I Iridium 64 Copper __ — __- - 50 Aluminium. 8 Iron_ 65, 139 Fluorine _-_____ 55 ISNARD. Hydrogen______ 58 Gallium ____ 55 Aluminium 8 Iodine_____. 6I, 62 GAY-LUSSAC, L. J. Iron _____ 67 Iodine ____-___ 6i JACQUELAIN, V. A. Lead _____ 72 Magnesium - 76 Chromium.. 44 INDEX. 147 JACQUELAIN, V. A. LIEBIG, J. MARIGNAC, C. Iodine ___- _ _ — 62 Bromine 21 Silver -__. Io7, IO8 Magnesium._.- 78 LIEBIG and REDTENBACHER. Strontium -____I 12 Phosphorus _ —- 97 Carbon _ 31 Tantalium _____I 17 Zinc_ __ _____ 35 Silver _.-. o___. IO8 Zirconium__ __1 36 JEGEL, J. (R. BUNSEN and) LIEBIG. (BERZELIUS and) MATHER, W. WV. Cerium _- 35 Carbon ______ 31 Aluminium ___ 7 JOHNSON and ALLEN. Lithium 73 MAUMEN., E. J. Coesium __ —- 25 LOEWIG, C. Chlorine _- __ 41 Bromine -— _ —— 21 Iron- _ __ _ ___67 LONGCHAMIP. Potassium.-... Ioo KEMPE. (LEICHTE and) Iagnesium __._ 76 Silver _________I8 Molybdenum___ ~85 LOUYET, P. MENDELEJEFF, D. KESSLER, F. CFluorine _______ 55 Cerium ______ 37 Antimony - I LUCCA, S. DE Didymium-__- _ 52 Arsen1ic -' -----— 3 Fluorine 55 Erbium _ 53 Chromium - ---- 45 Lanthanium ____ 70 KIRCHHOFF and BUNSEN. MACDONNELL, A. Uranium28 MACDONNELL, A. Uranium.......I28 CResium -_____24 Magnesium-___ 78 MERCER. Rubidium...0..Io2 KJERULFbidm T. I Magnesium___ __ 76, 139 Cesium -_____. 25 KJERULF, T. MAGNUS, G. Mercury 81, 140 Cerium ___. 35 Iron ____- ___ 65 MEYER, L. KLAPROTH, M. H. aMALLET, J. W. Molybdenum ___ 85 Potassium _____ 99 Lithium 74 Uranium -_____I128 StrOntium _____ II2 Manganese 79, 139 MILLON, E. KILAPROTH. (WOLLASTON MARCET. Iodine________ 62 and) Chlorine 37 Mercury 83 Bar1ium -. _ 1 _ _ __I3 Silver- _______I o6 MILLON and COMMAILLE. KLATZO, G. MARCHAND, R. F. Copper-__ ___ 50 Beryllium ___-__ I8 Tungsten._._.._I26 MITSCHERLICH, E. KRALOVANSZKY. Uranium _ _I29 Carbon30 Lithium 73 MARCHAND and SCHEERER. MOBERG, A. KRAUT. (GMELIN-) Magnesium —--- 76 Chromium-_____ 44 Boron I9 MARCHAND. (ERDMANN Molybdenum _ _ 83 Carbon -_ —---- 33 and) MOSANDER, C. G. Iodine62 ______Calcium- __ _27 Lanthanium ___ 68 Carbon 30 Titanium -.... 124 LAGERHJ-LM, P. Copper- _. ___. 49 MULDER, G. J. Bismuth_.._ ___ IS Hydrogen______.58 Tin.- -.I22 LAMY, A. Iron 66 Thallium __ I8 Mercury ______ 82 Nickel- _ 86, I39 Lanthanium ___ 67 Nickel_ __- ___ 86 Niobium___ ______. 89 LASSAIGNE. Selenium _ ____. I04 Nitrogen _ _ _ _ _ _ _ gI91 Nickel_.-_____ 86 Sulphur _- ____ I I4 NORDENFELDT. (SVANBERG LAURENT, A. MARIGNAC, C. and) Boron ___- _ 20 Barium ___ I5, I6 Magnesium — ___ 77 Chlorine ___- 40, 42 Bromine__ _.__ 21 NORLIN. (SVANBERG and) Lead_ 70, 39 Calcium.___ 27 Iron66 LEE, R. II. Carbon 32 Cobalt ____-___ 48 Cerium 35 ODLING, W. Nickel_.__. ___ 89 Chlorine ___ 39, 40 Aluminium __- - 8 LEFORT, J. Cobalt..____ 46 Osmium _.. —-------- 94 Chromium 45 Didymium ____5I OTTO, F. J. LEICHTE and KEMPE. Iodine 62 Cerium _ 34 Molybdenum ___ 85 Lanthanium 68 Lanthanium __.- 67 LENSSEN, E. Lead ___- _____ 72 Oxygen ----------- 95 Cadmium 24 Nickel ____- __ 87 LEVOI, A. Niobium __-____ go Palladium 95 Gold 56 Nitrogen _-__ 92 PELIGOT, E. Potassium.-... Ioo Potassium __ 99, IOO Chromium...... 44 148 INDEX. PELIGOT, E. ROSCOE, H. E. i STAS, J. S, Uranium_ _I 29, 131 Tungsten.....I128 Chlorine _____ 42 PELOUZE, J. Vanadium _. ___ 132 Hydrogen _.___ 59 Arsenic __-_____ I2 ROSE, H. Iodine ___.-.._ 63 Barium _ 15 Niobium.... 89, 90 Lead 72 Chlorine ______ 40 Tantalium ____- I i6 Lithium _ 75 Nitrogen -_____ 93 Titanium.....I.23 Nitrogen ____ 93 Phosphorus.... 96 RosE, H., and WEBER. Potassium -_____IOO Potassium -_ 1_00IOO Antimony _____ g9 Silver._-_._.109IO Silicon ------— 105 RosE, V. Sodium _- III Sodium -.__ __. I io Phosphorus _-_ 96 Sulphur. __ 115 Strontium ______112 Strontium ____ I112 STAS, J. S. (J. DUMAS and) PELOUZE and FREMY. ROTHOFF, E. Carbon ______- 30 Aluminium __ 8 Cobalt ----- - 46 STRECKER, A. PENNY, F. Nickel - _ 86 Carbon __ 32 Chlorine ____ 39 Rubidium ______ 2 Silver- - io8 Nitrogen ____ 92 RUSSELL, W. J. STROMEYER, F. Potassium _____ 99 Cobalt __- 47, 48 Cadmium 23 Silver ----- 0 — Io7 Nickel _.. _ 88, 89 Iron __ _- 65 Sodium —.....I IO Ruthenium Io3 Lithium _-_____ 73 PETTERSSON, O., and G. Strontium -____ I112 EKMAN. SACC, F. Strontium ___.- III, I39 Selenium -...0.IO5 Selenium ____ Io4 STRUVE, H. PHILLIPS, R. SALVETAT. Barium _-__ 15 Chlorine ____ 39 Barium I_ 15 Sulphur __- I I5 Phosphorus -_____ 96, I39 Calcium _.. 26 STRUVE, II., (L. SVANBERG PICCARD, J. Strontium _-___1I 12 and) Rubidium.____.Io 2 SCHEERIER, T. Molybdenum ___ 83 PIERRE, J. Magnesium__ 77, 78 Sulphur —-----— I I3, 39 Titanium.___ 124 SCHEERER, T. (MARCHAND SVANBERG, L. Platinum _ _-_ 98 and) Mercury 83 POPP, 0. Magnesium__ 76, 77 Nitrogen — ______ 92 Yttrium _ __ 133 SCIIEIBLER, C. SVANBERG and NORDENPotassium ------- 98, I39 Tungsten _____-I27 FELDT. PROUT, W. SCHIEL, J. Magnesium_ __- 77 Iodine __ ______ 6I Silicon _.-....Ioo6 SVANBERG and NORLIN. SCHNEIDER, R. Iron_66 RAMMELSBERG, C. Antimony 9 — SVANBERG and STRUVE. Cerium ___ 35, 36 Bismuth _-_- ___ 19 Molybdenum ___ 83 Lanthanium _ 68 Cobalt -------— 46 Niobium _____- 9 go Manganese 8- Tantalium I I6 Uranium ___I30, 131 Nickel ----— 87, 88 Tellurium _ _ I I7 RAWACK. Tungsten _ 1_ —-I25 THALtN. Manganese. __ 8I SCHROETTER, A. Lantbaniumn 70 REDTENBACHER. (LIEBIG Phosphorus-.__ 97 Thallium I I8 and) Selenium 1___ IO4 THENARD, L. J., and F. H. Carbon 31 SEFSTROEM, N. G. WOLLASTON. Silver -------— IO8 5Mercury 82 Iron 65 REGNAULT. Selenium _ — Io3 THENARD L. J., (FOURCROY Hydrogen _____ 57 SIEWART, MIa. and) Nitrogen -____ gI9 Chromium __ —- 45 Mercury _-_-_-_ 82 REICH, F., and T. RICHTER. Silicon _ ____ I5 THOMSEN, J. Indium __ 59 Silver __Io6, I39 Hydrogen _._- 59 RICHE, A. Sodium -- III, I39 THOMSON, T. Tungsten __ ___..I26 SOMMARUGA, E. VON. Aluminium _.__ 7 RICHTER, T. (F. REICH and) Cobalt _- ---- 47 Antimony ------ I40 Indium ---- 59 Nickel-.... —-- 88 Arsenic -______1 39 RIVOT, L. E. STAS, J. S. Barium ---— I4, I39 Iron- 67 Bromine __- ___ 22 Beryllium 17 Rhodium __ - ---.. IoI Carbon. —-— 32, 33 Bismuth — ____I-39 INDEX. 149 TH031SON, T. TURNER, E. WOEHILER and DEVILLE. Boron ----- 20, I40 Nitrogen 9 —--- 9 Boron __ 19 Cadmium 23 Silver _____.Io6 Graphon _-__ 33 Calcium -----— I39 Sulphur -------- II4 WOLF, C. Carbon ---— 29, 139 Cerium - - 36 Cerium 34 UNGER, B. WOLLASTON, F. H. Chlorine __ —--- I39 Antimony I i Calcium __-_._. 26 Chromium -_43, I39 Uranium _- I28 Carbon_ — _____ 28 Cobalt..1..._ 39 Chlorine _ _ 37 Copper -------- I39 Vanadium - I3I Copper -_-____- 49 Gold __ —--- 56 VAUQUELAIN, L. N. Hydrogen __ 57 IIydrogen —-—. 58 Lithium_ _-___ 73 Magnesium. 76 Iodine _._._._- - 6I VLAANDEREN, C. L. Mercury __-____ 82 Iron ____ —----- 139 Tin-_ 1_______ 22 Nitrogen__ —_ 9I Lead 1-..__._I.39 Phosphorus 96 Lithium_ -__ —- 73 Potassium _____ 99 Manesium I39 WACKENRODER, H. Silver ____ ___.Io6 Manganese.._I39 Iron 66 Sodium ____ I o Mercury -----— 140 WALLACE, W. Strontium ___- I 12 Nickel -_____- 139 Bromine ------ 22 Sulphur- _- --.1I 13 Nitrogen _.9, I39 WATTS, W. M. Zinc_ -____ I134 Phosphorus. I 39 Iridium _ _-_ —- 65 WOLLASTON and KLAPROT1H. Potassium.-..I 39 Osmium 94 Barium _-____- _ 13 Silver ----— 39 WEBER. (H. Ros and) WOLLASTON. (BERZELIUS Sodium __ —. 1 —-I39 Antimony 9 and) Strontium __-___I39 WEEREN, J. Lead 7I Sulphur_.-..._ I I4 Beryllium ____ 7 WOLLASTON. (L. J. THETin-_____ ____ I40 WELESKY, P. NARD and) Zinc ___ —-- ---- 39 Cobalt _ _... _ 48 Iron -.. __ ___ 65 Thorium -----------— 20 WENZEL. WREDE, F. VON Tin -_____ —----.122, 140 Silver __.. _ —- i o6 Carbon 32 TISSIER, C. WERTHEIM, J. Aluminium -.... 8 Uraniumn - __ 130 Titanium __ 23 WERTHER, H. Yttrium _ __ I 33 TROOST, L. Thallium. _ -__ I 9 Lithium ---— 74, 75 WILDENSTEIN, R. Tungsten ------ ----— 125 Chromium- ___. 45 ZETTNOW, E. TURNER, E. WING, C. H. Tungsten 1____I27 Barium I4 Cerium _ —----- 36 Zinc _- 34, I39 Chlorine- - 38 WINKLER, C. Zirconium I36 Lead __-___.. 71 Cobalt _- -- -- 48 ZSCHIESCHE, H. Manganese 8o Indium _ —- 60 Didymium -_ —- 52 Mercury —---- 82 Nickel_ —------ 88 Lanthanium 69 SMITHSONIAN MISCELLANEOUS COLLECTIONS. 441 THE CONSTANTS OF NATURE. PAIRT V. A RECALCULATION -OFTHE ATOMIC WEIGHTS. BY FRANK WIGGLESWOR'I'H CLARKE, S. B., Professor of Chemistry and Physics in the University of Cincinnati. WASHINGTON: S3MITHSONIAN INSTITUTION. 1882. JUDD & DETWEILER, PRI NTERS, WA8HINGTON, D. C. ADVERTISEMEI NT. The present publication is one of a series devoted to the discussion and more precise determination of various "Constants of Nature;" and forms the Fifth contribution to that subject published by this Institution. The First number of the series, embracing tables of "Specific Gravities" and of Melting and Boiling Points of Bodies, prepared by the same author, Prof. F. W. Clarke, was published in 1873. The Fourth part of the series, comprising a complete digest of the various "Atomic Weight" determinations of the chemical elements published since 1814, commencing with the well-known " Table of Equivalents" by Wollaston, (given in the Philosophical Transactions for that year,) compiled by Mr. George F. Becker, was published by the Institution in 1880. The present work which may be regarded as practically supplementary to that digest, (or perhaps rather as the memoir to which that digest is introductory,) comprises a very full discussion and re-calculation of the "Atomic Weights" from all the existing data, and the assignment of the most probable value to each of the elements. The manuscript of' the work was presented to the Institution in its completed form by Prof. F. W. Clarke, the cost of publication only being at the expense of the Smithsonian fund. SPENCER F. BAIRD, Secr:tary of Smithsonian. Institution. WASHINGTON, January, 1882. TABLE OF CONTENTS. PAGE. Introduction- vii Formulse for the Calculation of Probable Error_ __ xii I. Oxygen_~ ~. _ _ __ _ ____ _ __ I 2. Silver, Potassium, Sodium, Chlorine, Bromine, Iodine, and Sulphur__ 9 3. Nitrogen __ __39 4. Carbon- _ —--------------—.. — 50 5. Barium __- -. 57 6. Strontium __.- -64 7. Calcium _-_- _ 67 8. Lead____ _. - _ ____ 72 9. Fluorine ___ -- ___...__.____.____-______ _ 78 Io. Phosphorus _-__-_.__ -____.___.._____._ 82 I. Boron _______ 84 12. Silicon _ 85 I3. Lithium __ _ __87 I4. Rubidium ___ --- ___ __ go 15. Coesium __ _.______.. ___.__.___. ___ —---- - -- 91 I 6. Thallium ___ _.._____ __ ______.._ _ 93 17. Glucinum -____ __- — _- - ___ __96 I8. Magnesium___ - Ioo00 I9. Zinc- -__ __ _____ Io8 20. Cadmium___ __.-. II 21. Mercury, — 4. —--- 14 22. Chromium _ _ -— I 17 23. Manganese._ _1._ _ _ I27 24. Iron ___ — ____ 131 25. Copper ----—.. I35 26. Molybdenum...... __ _ __ _ - - - - - __'___._ _ I37 27. Tungsten -—....... —-— 7 I43 28. Uranium ___ —— _ 150 29. Aluminum __ ------ --. ___. _ I56 30. Gold_ _ __ __ _ _ 62 31. Nickel and Cobalt.-.......... — -- - -...... I64 32. Selenium _____ —-- -- 176 33. Tellurium ------ _i __ ____ _ _80 34. Vanadium 1-___ __ _ __ _ — - -— _____. _______. I83 35. Arsenic.. ——. I85 36. Antimony _ _ _ -__ __ ___ _ __88 37. Bismuth ________ —---— 202 (v) VI CONTENTS. PAGE. 38. Tin _ __ ____ 204 39. Titanium -_ _.. _ 207 40. Zirconium -_ _ _.. _________________________-. 212 41. Thorium _- - _ _ 214 42. Gallium_ __ _ _ _._ _ _. 218 43. Indium _ _ _ _ _ _ _ _ _ -- 219 44. Cerium.._________........................................220 45. Lanthanum _ - -229 46. Didymium __ -----—. —-------- -.. - ----. 236 47. The Yttrium Group. Scandium, Yttrium, Ytterbium, Erbium, Terbium, Phillipium, Decipium, Thulium, Samarium, etc. 240 48. Columbium (Niobium)....___ ---- __ __ 247 49. Tantalum 248 50. Platinum __ _ _ _ _ _ _ 249 5 I. Osmium __ __ -___ __ __254 52. Iridium __ __ - 255 53. Palladium ______ 256 54. Rhodium _ — _ ___ ___..-. 258 55. Ruthenium — __________ _-_ 259 Appendix - -_ ___ _ — 26I INTRODUCTION. In the autumn of 1877 the writer began collecting data relative to the determinations of atomic weights, with the purpose of preparing a complete resume of the entire subject, and of recalculating all the estimations. The work was fairly under way, the material was collected and partly discussed, when I received from the Smithsonian Institution a manuscript by Professor George F. Becker, entitled "Atomic Weight Determinations: a Digest of the Investigations Published since 1814." This manuscript, which has lately been issued as Part IV of the " Constants of Nature," covered much of the ground contemplated in my own undertaking. It brought together all the evidence, presenting it clearly and thoroughly in compact form; in short, that portion of the task could not well be improved upon. Accordingly, I decided to limit my own labors to a critical recalculation of the data; to combine all the figures upon a common mathematical basis, and to omit everything which could as well be found in Professor Becker's " Digest." At the very beginning of my work certain questions confronted me. Should I treat the investigations of different individuals separately, or should I combine similar data together in a manner irrespective of persons? For example, ought I, in estimating the atomic weight of silver, to take Stas' work by itself, Marignac's work by itself, and so on, and then average the results together; or should I rather combine all series of figures relating to the composition of potassium chlorate into one mean value, and all the data concerning the composition of silver chloride into another mean, and, finally, compute from such general means the constant sought to be established? The latter plan was finally adopted; in fact, it was rendered necessary by the method of least squares, which method was alone adequate to supply me with good processes for calculation. (vii) VIII INTRODUCTION. The mode of discussion and combination of results was briefly as follows. The formulae employed are given in another chapter. I began with the ratio between oxygen and hydrogen; in other words, with the atomic weight of oxygen referred to hydrogen as unity. Each series of experiments was taken by itself, its arithmetical mean was found, and the probable error of that mean was computed. Then the several means were combined according to the appropriate formula, each receiving a weight dependent upon its probable error. The general mean thus established was taken as the most probable value for the atomic weight of oxygen, and, at the same time, its probable error was mathematically asssigned. Next in order came a group of elements which were best discussed together, namely, silver, chlorine, potassium, sodium, bromine, iodine, and sulphur. For these elements there were data from thirteen experimenters. All similar figures were first reduced to common standards, and then the means of individual series were combined into general means. Thus all the data were condensed into twenty ratios, from which several independent values for the atomic weight of each element could be computed. The probable errors of these values, however, all involved the probable error of the atomic weight of oxygen, and were, therefore. higher than they would have been had the latter element not entered into consideration. Here, then, we have suggested a chief peculiarity of this whole revision. The atomic weight of each element involves the probable errors of all the other elements to which it is directly or indirectly referred. Accordingly, an atomic weight determined by reference to elements whose atomic weights have been defectively ascertained will receive a high probable error, and its weight, when combined with other values, will be relatively low. For example, an atomic weight ascertained by direct comparison with hydrogen will, other things being equal, have a lower probable error than one which is referred to hydrogen through the intervention of oxygen; and a metal whose equivalent involves only the probable error of oxygen INTRODUCTION. IX will be more exactly known than one which depends upon the greater errors of silver and chlorine. These'points will appear more clearly evident in the subsequent actual discussions. But although the discussion of atomic weights is ostensibly mathematical, it cannot be purely so. Chemical considerations are necessarily involved at every turn. In assigning weights to mean values I have been, for the most part, rigidly guided by mathematical rules; but in some cases I have been compelled to reject altogether series of data which were mathematically excellent, but chemically worthless because of constant errors. In certain instances there were grave doubts as to whether particular figures should be included or rejected in the calculation of means; there having been legitimate reasons for either procedure. Probably many chemists would differ with me upon such points of judgment. In fact, it is doubtful whether any two chemists, working independently, would handle all the data in precisely the same way, or combine them so as to produce exactly the same final results. Neither would any two mathematicians follow identical rules or reach identical conclusions. In calculating the atomic weight of any element those values are assigned to other elements which have been determined in previous chapters. Hence a variation in the order of discussion might lead to slight differences in the final results. As a matter of course the data herein combined are of very unequal value. In many series of experiments the weighings have been reduced to a vacuum standard; but in most cases chemists have neglected this correction altogether. In a majority of instances tthe errors thus introduced are slight; nevertheless they exist, and interfere more or less with all attempts at a theoretical consideration of the results. For example, they affect seriously the investigation of Prout's hypothesis, and are often great enough to account for seeming exceptions to it. Such questions as these will be considered in the appendix. Another serious source of error affecting many of the re X INTRODUCTION. suits was not discovered until recently. A large number of computations had been actually finished, involving, among other things, the greater part of Stas' work, when Dumas published his investigation upon the occlusion of oxygen by silver. Here it was shown that a very great number of atomic weight determinations must have been vitiated by constant errors, which, though constant for each series, were probably of different magnitude in different series, and, therefore, could not be systematically corrected for. At the time of the announcement of this discovery of Dumas my work was so far under way that I thought it best to complete my discussion without reference to it, and then to study its influence in the appendix. In the chapter upon aluminum, however, it will be noted that Mallet eliminated this error in great part from his experimental results. Necessarily, this work omits many details relative to experimental methods, and particulars as to the arrangements of special forms of apparatus. For such details original memoirs must be consulted. Their inclusion here would have rendered the work unwarrantably bulky. There is such a thing as over-exhaustiveness of treatment, which is equally objectionable with under-thoroughness. Of course, none of the results reached in this revision can be considered as final. Every one of them is liable to repeated corrections. To my mind the real value of the work, great or little, lies in another direction. The data have been brought together and reduced to common standards, and for each series of figures the probable error has been determined. Thus far, however much my methods of combination may be criticized, I feel that my labors will have been useful. The ground is now cleared, in a measure, for future experimenters; it is possible to see more distinctly what remains to be done; some clues are furnished as to the relative merits of different series of results. I hope to be able, from time to time, as new determinations are published, to continue the task here begun, and perhaps, also, to add, in the near future, some data of my own establishing. In addition to the usual periodicals the following works INTRODUCTION. XI have been freely used by me in the preparation of this volume: BERZELIUS, J. J. Lehrbuch der Chemie. 5 Auflage. Dritter Band. SS. 1147-1231. 1845. VAN GEUNS, W. A. J. Prceve eener Geschiedenis van de lEquivalentgetallen der Scheikundige Grondstoffen en van hare Soortelijke Gewigten in Gasvorm, voornamelijk in Betrekking tot de vier Grondstoffen der Bewerktuigde Natuur. Amsterdam, 1853. MULDER, E. Historisch-Kritisch Overzigt van de Bepalingen der iEquivalent-Gewigten van 13 Eenvoudige Ligchamen. Utrecht, 1853. MULDER, L. Historisch-Kritisch Overzigt van de Bepalingen der }Equivalent-Gewigten van 24 Metalen. Utrecht, 1853. OUDEMANS, A. C., Jr. Historisch-Kritisch Overzigt van de Bepaling der }Equivalent-Gewigten van Twee en Twintig Metalen. Leiden, 1853. STAS, J. S. Untersuchungen iiber die Gesetze der Chemischen Proportionen fiber die Atomgewichte und ihre gegenseitigen Verhifltnisse. Uebersetzt von Dr. L. Aronstein. Leipzig, 1867. The four Dutch monographs above cited are especially valuable. They represent a revision of all atomic weight data down to 1853, as divided between four writers. XII INTRODUCTION. FORMULiE FOR THE CALCULATION OF PROBABLE ERROR. Although the ordinary formula for the probable error of an arithmetical mean is familiar to all physicists, it is perhaps best to reproduce it here, as follows: (1.) =.4-.6745n (n Here n represents the number of observations or experiments in the series, while S is the sum of the variations of the individual results from the mean. In combining several arithmetical means, representing several series, into one general mean each receives a weight indicated by its probable error; greater as the latter becomes less, and vice versa. Let A, B, C, etc., be such mean results, and a, b, c, their probable errors respectively. Then the general mean is determined by this formula: A B3 C (2.) M_ C_ I II For the probable error of this general mean we have: (3.) \/ -; X x I In the calculation of atomic and molecular weights the following formulae have been employed. For assistance in connection with them my thanks are due to Professors H. T. Eddy and E. W. Hyde of the University of Cincinnati. Using, as before, capital letters to represent known quantities and small letters for their probable errors respectively, INTRODUCTION. XIII we have for the sum or difference of two quantities, A and B: (4.) e = l/a2 + b2 For the product of A multiplied by B the probable error is (5.) V = b/(Ab)2 + (Ba)' For the product of three quantities, ABC: (6.) e =/(BCa)2 + (ACb)2 + (ABc)2 For a quotient, A the probable error becomes (7.) e +A ) A Given a proportion, A: B:: C: x, the probable error of the fourth term is as follows: (8.) I(e)2+ (Cb)2 + (Bc)( A This formula is used in nearly every atomic weight calculation, and is, therefore, exceptionally important. Rarely a more complicated case arises in a proportion of this kind: A: B::C + ~x: D -+ x In this proportion the unknown quantity occurs in two terms. Its probable error is found by this expression, and is always large: (9.) e _.D) 2 Ab2) + A2d2 j(A _-z))i (B2a2 -- A(2 ) + (A - B)2 When several independent values have been calculated for an atomic weight they are treated like means, and combined according to formula (2) and (3.) Each final result xIV INTRODUCTION. is, therefore, to be regarded as the general mean of all reliable determinations. This method of combination may not be the best one theoretically possible, but it seemed to be the only one practically available. The data are too imperfect to warrant the use of much more elaborate processes of discussion. RECALCULATION OF THE ATOMIC WEIGHTS. OXYGEN. The ratio between oxygen and hydrogen is the foundation upon which the entire system of atomic weights depends. Hence, the accuracy of its determination has, from the beginning, been recognized as of extreme importance. A trifling error here may become cumulative when repeated through a moderate series of other ratios. Leaving out of account the earliest researches, which have now only a historical value, we find that three methods have been employed for fixing this important constant. First, the synthesis of water, effected by passing hydrogen gas over red hot oxide of copper. Secondly, the exact determination of the relative density of the two gases. Thirdly, by weighing the quantity of water formed upon the direct union of a known volume of hydrogen with oxygen. The first of these methods has been employed in three leading investigations, namely, by Dulong and Berzelius,* by Dumas, and by Erdmann and Marchand. The essential features of the method are in all cases the same. Hydrogen gas is passed over heated oxide of copper, and the water thus formed is collected and weighed. From this weight and the loss of weight which the oxide undergoes, the exact composition of water is readily calculated. Dulong and Berzelius made but three experiments, with the following results for the percentages of oxygen and hydrogen in in water: 0. H. 88.942 II.058 88.809 1. I9I 88.954 I.o46 * Thomson's Annals of Philosophy, July, I82I, p. 50. THE ATOMIC WEIGHTS. These figures, rather roughly determined, and by no means exact enough to meet the requirements of modern science, give a mean value of 16.021 for the atomic weight of oxygen. As the weighings were not reduced to a vacuum, this correction was afterwards applied by Clark,* who showed that these syntheses really make 0 - 15.894; or, in Berzelian terms, if O = 100, H- = 12.583. In 1842 Dumast published his elaborate investigation upon the composition of water. The first point was to get pure hydrogen. This gas, evolved from zinc and sulphuric acid, might contain oxides of nitrogen, sulphur dioxide, hydrosulphuric acid, and arsenic hydride. These impurities were removed in a series of wash bottles; the H2S by a solution of lead nitrate, the H3As by silver sulphate, and the others by caustic potash. Finally, the gas was dried by passing through sulphuric acid, or, in some of the experiments, over phosphorus pentoxide. The copper oxide was thoroughly dried, and the bulb containing it was weighed. By a current of dry hydrogen all the air was expelled from the apparatus, and then, for ten or twelve hours, the oxide of copper was heated to dull redness in a constant stream of the gas. The reduced copper was allowed to cool in an atmosphere of hydrogen. The weighings. were made with the bulbs exhausted of air. The following table gives the results: Column A contains the symbol of the drying substance. B gives the weight of the bulb and copper oxide. C, the weight of bulb and reduced copper. D, the weight of the vessel used for collecting the water. E, the same, plus the water. F, the weight of oxygen. G, the weight of water formed. H, the crude equivalent of H when O = 10,000. I, the equivalent of H, corrected for the air contained in the sulphuric acid employed. This correction is not explained, and seems to be questionable. * Philosophical Magazine, 3d series, 20, 34I. t Compt. Rend., 14, 537. A. B. C. D. E. F. G. H. I2,t _____ 291.985 278.806 480.807 495.634 I3.179 14.827 1250.5 1249.6 -_ -...... 344-548 324. I86 488.227 51 I.132 20.362 22.905 1249.0 1248.0 " _.............. 316.671 296.175 439.7II 462.764 20.495 23.053 1248.I 1247.2 PO..05.__._._._____ 625.829 568.825 884. I90 948.3:'3 57.004 64.044 1250.6 249.0 H2SO4._____. 804-546 728.182 887.331 973.291 76.364 85.960 1256.2 1254.6 533-726 490.I55 867-I59 916.206 43.57I 49.047 1256.3 1255.0 " ___............. 66I.915 627.104 839.304 878.482 34.811 39.178 1254.6 1253.3 P2, 612.625 566.738 824.624 876.244 45.887 51.623 1250.0 1249.0 4" 904.643 844.612 822.660 890.246 60.031 67.586 1258.3 I255.1 i 112SO4____. _ __ 642.325 590-487 74I.095 799-4I7 5I.838 58.320 1250.4 1248.9 < P20. 0............. 587.645 535.-I37 874.832 933.9I0 52-508 59.o78 251.2 1249.0 5872874832 I251 -" -......... 673.280 613.492 931.487 998.700 59-789 67.282 1253.3 1250.8 }I2SO4 -- 660.855 598.765 632.374 752.273 62.90 9 69.899 1257-7 1254.8 "c __.............642-325 590.487 741.097 799-455 5I.838 58.36o 1258.I 1256.2 " -............ 937.845 881.362 1064.762 1128.319 56.483 1 63.577 1255.8 1252.2 P20.5 _.^__ 756.352 719.563 878.640 920.030 36.789 4I-390 1250.6 1249.1 - —... 754.162 720.000 887.817 926.275 34.I62 38.458 1257.3 1255.1 - ____________l__1 759.762 1 727.632 888.662 924.837 32. 133 36.175 I257.5 1254.7 " -.............. 747.652 716.825 877.862 912-539 30.827 34-677 1248.8 1248.o Means.____.. 1253.3 1251.5 4 THE ATOMIC WEIGHTS. In the sum total of these nineteen experiments, 840.161 grammes of oxygen form 945.439 grammes of water. This gives, in percentages, for the composition of water, oxygen 88.864; hydrogen, 11.136. Hence the atomic weight of oxygen, calculated in mass, is 15.9608. In the following column the values are given as deduced from the individual data given under the headings F and G: 15.994 I6.0o4 I6.024 I5.992 15.916 I5.9I6 15.943 i6.ooo 15.892 I5.995 15-984 15.958 15.902 I5.987 15.926 15.992 I5.904 15.900 I6.oI5 Mean, 15.9607, with a probable error of -.0070. In calculating the above column several discrepancies were noted, probably due to misprints in the original memoir. On comparing columns B and C with F, or D and E with G, these anomalies chiefly appear. They were detected and carefully considered in the course of my own calculations; and, I believe, eliminated from the final result. The paper by Erdmann and Marchand* followed closely after that of Dumas. The method of research was essentially the same as that of the latter chemist, varying only in points of comparatively unimportant detail. The results are given in two series, in one of which the weighings were * Journ. f. Prakt. Chem., 1842, bd. 26, s. 46I. OXYGEN'. 5 not actually made in vacuo, but were, nevertheless, reduced to a vacuum standard. The second series represents actual vacuum weighings. The quantity of water formed in each experiment, was from 41.664 to 95.612 grammes. I give below only the percentages of oxygen and hydrogen in water as deduced from Erdmann and Marchand's data: First Series. 0. H. 88.836 I.164 88.82I 11.179 88.874 11.126 88.868 I I. 132 Second Series. O. H. 88.887 11.113 88.898 1 1. 102 88.895 I I.I05 88.899 I I.IOI Hence, the atomic weight of oxygen is, as follows: First Series. Second Series. I5.915 I5.997 I5.891 I6.015 I5.976 i6.0oo I5.966 i6.0o6 Mean, I5.9369, =- o0138 Mean, I6.0095, 4-.0030 The effect of discussing these two series separately is somewhat startling. It gives to the four experiments in Erdmann and Marchand's second group a weight vastly greater than their other four and Dumas' nineteen taken together. For so great a superiority as this there is no adequate reason; and it is highly probable that it is due almost entirely to fortunate coincidences, rather than to greater accuracy of work. We will, therefore, treat Erdmann and Marchand's experiments as one series, giving all equal weight, and then combine them with the results obtained by Dumas. We now have 6 THE ATOMIC WEIGHTS. By Dumas 0- I5.9607, ~.0070 By Erdmann and Marchand ___-___ 0 = I5.9733,.0OI13 General mean______- 0 I5.9642, -.oo60 In discussing the relative density of oxygen and hydrogen gases we need only consider the more modern researches of Dumas and Boussingault, and of Regnault. As the older work has some historical value, I may in passing just cite its results. For the density of hydrogen we have.0769, Lavoisier;.0693, Thomson;.092, Cavendish;.0732, Biot and Arago;.0688, Dulong and Berzelius. For oxygen there are the following determinations: 1.087, Fourcroy, Vauquelin, and Seguin; 1.103, Kirwan; 1.128, Davy; 1.088, Allen and Pepys; 1.1036, Biot and Arago; 1.1117, Thomson; 1.1056, De Saussure; 1.1026, Dulong and Berzelius; 1.106, Buff; 1.1052, Wrede.* In 1841 Dumas and Boussingaultt published their determinations of gaseous densities. For hydrogen they obtained values ranging from.0691 to.0695; but beyond this mere statement they give no details. For oxygen three determinations were made, with the following results: 1.1055 I.1058 I.I057 Mean, I.Io567, +.o0006 If we take the two extreme values given above for hydrogen, and regard them as the entire series, they give us a mean of.0693, i-.00013. This mean hydrogen value, combined with the mean oxygen value, gives for the atomic weight of the latter element the number 15.9538, -.031. Regnault's researches, published four years later,t were of * For Wrede's work, see Berzelius' Jahresbericht for i843. For Dulong and Berzelius, see the paper already cited. All the other determinations are taken from Gmelin's Handbook, Cavendish edition, v. I, p. 279. t Compt. Rend., 12, 1oo5. Compare also with Dumas, Compt. Rend., I4, 537.. Compt. Rend., 20, 975. OXYGEN. 7 a more satisfactory kind. Indeed, they are among the classics of physical science; and probably approach as near to absolute accuracy as is possible for experiment. For hydrogen three determinations of density gave the following results:.06923.o6932.o6924 Mean,.o69263,.oooo000019 For oxygen four determinations were made, but in the first one the gas was contaminated by traces of hydrogen, and the value obtained, 1.10525; was, therefore, rejected by Regnault as too low. The other three are as follows: I.I056I I1.10564.io0565 Mean, I. I05633, 4.ooooo8 Now, combining the hydrogen and oxygen series, we have for the atomic weight of oxygen, 15.9628, ~.0044.* Upon combining the result of Regnault's work with that from Dumas and Boussingault's we get the following value: From Dumas and Boussingault _._.. O = I5.9538, -.o03I From Regnault_ _-___0________ O = I5.9628, -.0oo44 General mean ______ O I5.9627, -.0043 This result, it will be seen, agrees remarkably well with that obtained in the experiments upon the synthesis of water. * Since these computations were made, Professor John Le Conte has called my attention to the existence of slight numerical errors in Regnault's own reductions. As corrected by Le Conte, Regnault's figures give I.105612 for the density of oxygen, and 0.o69269 for that of hydrogen. Hence the atomic weight of O becomes I5.96II, instead of 15.9628. The difference is slight, but still it ought not to be ignored. All the computations in the body of this work, having been finished before I received Professor Le Conte's figures, must stand, nevertheless, as they are. For further details Le Conte refers to Phil. Mag., (4,) 27, p. 29, i864; and also to the Smithsonian Report for I878, p. 428. 8 THE ATOMIC WEIGHTS. The third method indicated at the beginning of this discussion has been recently employed in part by J. Thomsen* of Copenhagen. Unfortunately this chemist has not published the details of his work, but only the end results. These serve to confirm the values for oxygen fixed by other methods, but they cannot well be included in the systematic discussion. Partly by the oxidation of hydrogen over heated copper oxide, and partly by its direct union with oxygen, Thomsen finds that at the latitude of Copenhagen, and at sea level, one litre of dry hydrogen at 0~ and 760 mm. pressure will form.80411 gramme of water. According to Regnault, at this latitude, level, temperature, and pressure, a litre of hydrogen weighs.08954 gramme. From these data, 0 = 15.9605. It will be seen at once that Thomsen's work depends in great part upon that of Regnault, and yet that it affords an admirable reinforcement of the latter. It is now plain, in conclusion, that all the different lines of research point to an atomic weight for oxygen a little below 16.00. Five distinct investigations confirm each other wonderfully. Upon combining the values obtained by the two chief methods we get the following final results: From synthesis of water_ 0 I15.9642, 4-.oo6o From gaseous densities-_0_ _ O - 1 5.9627, -.0043 In the general mean the atomic weight of oxygen becomes 15.9633, with a probable error of =+.0035.t * Ber. d. Deutsch. Chem. Gesellschaft, I870, s. 928. t Le Conte's correction of Regnault's figures introduced here would make O - I5.9622, instead of I5.9633. Difference,.ooII. SILVER, POTASSIUM, ETC. 9 SILVER, POTASSIUM, SODIUM, CHLORINE, BROMINE, IODINE, AND SULPHUR. The atomic weights of these seven elements depend upon each other to so great an extent that they can hardly be considered independently. Indeed, chlorine, potassium, and silver have always been mutually determined. From the ratio between silver and chlorine, the ratio between silver and potassium chloride, and the composition of potassium chlorate, these three atomic weights were first accurately fixed. Similar ratios, more recently worked out by Stas and others, have rendered it desirable to include bromine, iodine, sulphur, and sodium in the same general discussion. Several methods of determination will be left altogether out of account. For example, in 1842 Marignac* sought to fix the atomic weight of chlorine by estimating the quantity of water formed when hydrochloric acid gas is passed over heated oxide of copper. IHis results were wholly inaccurate, and need no further mention here. A little later Laurentt' redetermined the same constant from the analysis of a chlorinated derivative of naphthalene. This method did not admit of extreme accuracy, and it presupposed a knowledge of the atomic weight of carbon; hence it may be properly disregarded. Maumen6e's analyses of the oxalate and acetate of silver gave good results for the atomic weight of that metal; but they also depend for their value upon our knowledge of carbon, and will, therefore, be discussed further on with reference to that element. Let us now consider the ratios upon which we must rely for ascertaining the atomic weights of the seven elements in question. After we have properly arranged our data we may then discuss their meaning. First in order we may * Compt. Rend., 14, 570. Also, Journ. f. Prakt. Chem., 26, 304. t Compt. Rend., I4, 456. Journ. f. Prakt. Chem., 26, 307. + Ann. d. Chim. et d. Phys., (3,) I8, 41. 1846. 10 THE ATOMIC WEIGHTS. conveniently take up the percentage of potassium chloride obtainable from the chlorate. The first reliable series of experiments to determine this percentage was made by Berzelius.* All the earlier estimations were vitiated by the fact that when potassium chlorate is ignited under ordinary circumstances a little solid material is mechanically carried away with the oxygen gas. Minute portions of the substance may even be actually volatilized. These sources of loss were avoided by Berzelius' who devised means for collecting and weighing this trace of potassium chloride. All the successors of Berzelius in this work have benefitted by his example; although for the methods by which loss has been prevented we must refer to the original papers of the several investigators. In short, then, Berzelius ignited potassium chlorate, and determined the percentage of chloride which remained. Four experiments gave the following results: 60.854 60.850 60.850 6o.85i Mean, 60.85I, with a probable error of ~.ooo6 The next series was made by Penny,t in England, who worked after a somewhat different method. He treated potassium chlorate with strong hydrochloric acid in a weighed flask, evaporated to dryness over a sand bath, and then found the weight of the chloride thus obtained. His results are as follows, in six trials: 60.825 60.822 6o.815 60.820 60.823 60.830 Mean, 60.8225, -~-.OO4 * Poggend. Annalen, 1826, bd. 8, s. I. t Phil. Transactions, 1839, p. 20. SILVER, POTASSIUM, ETC. 11 In 1842 Pelouze* made three estimations by the ignition of the chlorate, with these results: 60.843 60.857 60.830 Mean, 60.843, --.0053 Marignac, in 1842,t worked with several different recrystallizations of the commercial chlorate. He ignited the salt, with the usual precautions for collecting the material carried off mechanically, and also examined the gas which was evolved. He found that the oxygen from 50 grammes of chlorate contained chlorine enough to form.003 gramme of silver chloride. Here are the percentages found by Marignac: In chlorate once crystallized _ _______~ 60.845 In chlorate once crystallized _____ 60.835 In chlorate twice crystallized-_ _.... _. 60.833 In chlorate twice crystallized__ _ _____ 60. 844 In chlorate three times crystallized --— _ _ —- 60.839 In chlorate four times crystallized _ _-..- 60.839 Mean, 60.8392, ~-.0013 In the same paper Marignac describes a similar series of experiments made upon potassium perchlorate, KC104. In three experiments it was found that the. salt was not quite free from chlorate, and in three more it contained traces of iron. A single determination upon very pure material gave 46.187 per cent. of oxygen and 53.813 of residue. In 1845 two series of experiments were published by Gerhardt.t The first, made in the usual way, gave these results: 6o.87I 6o.88I 60.875 Mean, 60.8757, -.0020 *Compt. Rend., 15, 959. t Ann. d. Chem. u. Pharm., bd. 44, s. I8. I Compt. Rend., 21, I280. 12 THE ATOMIC WEIGHTS. In the second series the oxygen was passed through a weighed tube containing moist cotton, and another filled with pumice stone and sulphuric acid. Particles were thus collected which in the earlier series escaped. From these experiments we get60.947 60.947 60.952 Mean, 60.9487, 4-.ooII These last results were afterwards sharply criticized by Marignac,* and their value seriously questioned. The next series, in order of time, is due to Maumene.t This chemist supposed that particles of chlorate, mechanically carried away, might continue to exist as chlorate, undecomposed; and hence that all previous series of experiments might give too high a value to the residual chloride. In his determinations, therefore, the ignition tube, after expulsion of the oxygen, was uniformly heated in all its parts. Here are his percentages of residue: 60.788 6o. 790 60.793 6o. 793 60.7 91I 60. 785 60.795 60. 795 Mean, 60.791, --.0009 The question which most naturally arises in connection with these results is, whether portions of chloride may not have been volatilized, and so lost. Closely following Maumene's paper there is a short note by Faget,.: giving certain mean results. According to this chemist, when potassium chlorate is ignited slowly, we get * Supp. Bibl. Univ. de Gen6ve, Vol. I. t Ann. d. Chim. et d. Phys., (3,) I8, 7I. 1846. T Ann. d. Chim. et d. Phys., (3,) I8, 80. 1846. SILVER, POTASSIUMn ETC. 13 60.847 per cent. of residue. When the ignition is rapid, we get 60.942. As no detailed experiments are given, these figures can have no part in our discussion. Last of all we have two series determined by Stas.* In the first series we have the results obtained by igniting the chlorate. In the second series the chlorate was reduced by strong hydrochloric acid, after the method followed by Penny: First Series. 60.8380 60.8395 60.8440 60.8473 6o.8450 Mean, 60.84276, 4-.ooI2 Second Series. 60.850 60.853 6o.844 Mean, 60.849,.00oI7 In these experiments every conceivable precaution was taken to avoid error and ensure accuracy. All weighings were reduced to a vacuum standard; from 70 to 142 grammes of chlorate were used in each experiment; and the chlorine carried away with the oxygen in the first series was absorbed by finely divided silver and estimated. It is difficult to see how any error could have crept in. Now, to combine these different series of experiments. Berzelius, mean result ___ __ _ _ _ 6o.85I, +-.ooo6 Penny, " 60.8225, +-.OO4 Pelouze, " 60.843, -.0053 Marignac, _________________ __ __60.8392, 4-.ooI3 Gerhardt, Ist " __ _ ___ _ ______ 60.8757, ~-.0020 2d "- -..__._.___- - ___- 60.9487, 4-.ooI Maumen6, " 60o.791, -.0009 Stas, Ist " _____. ________ 60.8428, ~.0012 " 2d " ----— 60.849, 4-.0017 General mean, from all nine series, representing forty experiments ____________ __ __ 60.846, -.00038 * See Aronstein's Translation, p. 249. 14 THE ATOMIC WEIGHTS. This value is exactly that which Stas deduced from both of his own series combined, and gives great emphasis to his wonderfully accurate work. It also finely illustrates the compensation of errors which occurs in combining the figures of different experimenters. Similar analyses of silver chlorate have been made by Marignac and by Stas. Marignac's figures I have not been able to find,* and Stas gives but two experiments. The following are his percentages of oxygen in silver chlorate:t 25.081 25.078 Mean, 25.0795, A-.OOIO For the direct ratio between silver and chlorine there are seven available series of experiments. Here, as in many other ratios, the first reliable work was done by Berzelius.T He made three estimations, using each time twenty grammes of pure silver. This was dissolved in nitric acid. In the first experiment the silver chloride was precipitated and collected on a filter. In the second and third experiments the solution was mixed with hydrochloric acid in a flask, evaporated to dryness, and the residue then fused and weighed without transfer. One hundred parts of silver formed of chloride: * Since all the calculations were finished I have secured a copy of Marignac's figures. They are as follows: The third column gives the percentage of O in AgCIO,. 24.510 grm. AgC103 gave 18.3616 AgCl. 25.103 25.809.. it I9.3345 " 25.086 30.306 " " 22.7072 " 25.074 28.358 " " 21.2453 25.082 28.287 " " 21.1833 " 25.113 57. 70. " 42.8366 " 25.072 Mean, 25.o088, +-.0044 The introduction of these figures into the subsequent calculations could not produce any appreciable result. They would practically vanish from the general mean. However, they serve here as confirmation of Stas' work. t Aronstein's Translation, p. 214. 1 Thomson's Annals of Philosophy, 1820, v. I5, p. 89. SILVER, POTASSIUM, ETC. 15 132.700 132.780 I32.790 Mean, I32.757, ~.019 Turner's work* closely resembles that of Berzelius. Silver was dissolved in nitric acid and precipitated as chloride. In experiments one, two, and three the mixture was evaporated and the residue fused. In experiment four the chloride was collected on a filter. A fifth experiment was made, but has been rejected as worthless. The results were as follows: In a third column I put the quantity of AgCl proportional to 100 parts of Ag. 28.407 grains Ag gave 37.737 AgCI. 132.844 4I.917 " " 55.678 I 32.829 40.oo6 "c " 53 I43 " 132.837 30.922 c" " 41.070 " 132.8I8 * Mean, i32.832, 4-.0038 The same general method of dissolving silver in nitric acid, precipitating, evaporating, and fusing without transfer of material was also adopted by Penny.t His results for 100 parts of silver are as follows, in parts of chloride: I32.836 132.840 I32.830 132.840 132.840 132.830 132.838 Mean, I32.8363, --.0012 In 1842 Marignace found that 100 parts of silver formed 132.74 of chloride, but gave no available details. Later,l Phil. Transactions, 1829, 29I. t Phil. Transactions, 1839, 28. + Ann. Chem. Pharm., 44, 21., See Berzelius' Lehrbuch, 5th Ed., Vol. 3, pp. 1192, II93. 16 THE ATOMIC WEIGHTS. in another series of determinations, he is more explicit, and gives the following data: The weighings were reduced to a vacuum standard. 79.853 grm. Ag gave io6.o08 AgC1. Ratio, I32.844 69.905 " 92.864 " I32.843 64-905 " 86.210 " 132.825 92.362 " 122.693 " I32.839 99.653,, 132.383 " I32.844 Mean, I32.839, __.0024 The above series all represent the synthesis of silver chloride. Maumene* made analyses of the compound, reducing it to metal in a current of hydrogen. His experiments make 100 parts of silver equivalent to chloride: 132.734 132.754 132.724 I32.729 132.741 Mean, I32.7364, 4-.0077 By Dumast we have the following estimations: 9.954 Ag gave I3.227 AgC1. Ratio, 132.882 19.976 " 26.542 " I32.869 Mean, I32.8755, ~4.0044 Finally, there are seven determinations by Stas,t made with his usual accuracy and with every precaution against error. In the first, second, and third, silver was heated in chlorine gas, and the synthesis of silver chloride thus effected directly. In the fourth and fifth silver was dissolved in nitric acid, and the chloride thrown down by passing hydrochloric acid gas over the surface of the solution. The whole was then evaporated in the same vessel, and the chloride fused, first in an atmosphere of hydrochloric acid, * Ann. d. Chim. et d. Phys., (3,) I8, 49. I846. t Ann. Chem. Pharm., I 3, 21. I86o. + Aronstein's Translation, p. I7I. SILVER, POTASSIUM, ETC. 17 and then in a stream of air. The sixth synthesis was similar to these, only the nitric solution was precipitated by hydrochloric acid in slight excess, and the chloride thrown down was washed by repeated decantation. All the decanted liquids were afterwards evaporated to dryness, and the trace of chloride thus recovered was estimated in addition to the main mass.'The latter was fused in an atmosphere of HCl. The seventh experiment was like the sixth, only ammonium chloride was used instead of hydrochloric acid. From 98.3 to 399.7 grammes of silver were used in each experiment, the operations were performed chiefly in the dark, and all weighings were reduced to vacuum. In every case the chloride obtained was beautifully white. The following are the results in chloride for 100 of silver: 132.841 132.843 I32.843 132.849 132.846 I32.848 I22.8417 Mean, I32.8445, ~-.oo0o8 We may now combine the means of these seven series, representing in all thirty-three experiments. One hundred parts of silver are equivalent to chlorine, as follows: Berzelius - -32.757, -.0190 Turner __ 32.832, —.o0038 Penny- _-______ _____ 32.8363, +.0012 Marignac 32.839, ~.0024 Maumen_ ____32.7364, -.0077 Dumas __-______ __________ 32.8755, 4.0044 Stas 32.8445, -4-.o008 General mean _-_____ 32.8418, ~-.ooo6 Here, again, we have a fine example of the evident compensation of errors among different series of experiments. We have also another tribute to the accuracy of Stas, since this general mean varies from the mean of his results only within the limits of his own variations. 18 THE ATOMIC WEIGHTS. The ratio between silver and potassium chloride, or, in other words, the weight of silver in nitric acid solution which can be precipitated by a known weight of KC1, has been fixed by Marignac and by Stas. Marignac,* reducing all weighings to vacuum, obtained these results. In the third column I give the weight of KC1 proportional to 100 parts of Ag. 4.7238 grmn. Ag- 3.2626 KC1. 69.067 21.725 c" I5.00 " 69.050 21.759 " I5.028 " 69.066 21.909 15.131 " 69.063 22.032 I5.216 " 69.063 25. I22 " I7-350 69.063 Mean, 69.062, ~.0017 Stas' experiments upon this ratio may be divided into two series.t In the first series the silver was slightly impure, but the impurity was of known quantity, and corrections could therefore be applied. In the second series pure silver was employed. The potassium chloride was from several different sources, and in every case was purified with the utmost care. From 10.8 to 32.4 grammes of silver were taken in each experiment, and the weighings were reduced to vacuum. The method of operation was, in brief, as follows: A definite weight of potassium chloride was taken, and the exact quantity of silver necessary, according to Prout's hypothesis, to balance it was also weighed out. The metal, with' suitable precautions, was dissolved in nitric acid, and the solution mixed with that of the chloride. After double decomposition the trifling excess of silver remaining in the liquid was determined by titration with a normal solution of potassium chloride. One hundred parts of silver required the following of KC1: *See Berzelius' Lehrbuch, 5th edition, Vol. 3, pp. I 192, II93. t Aronstein's Translation, pp. 250-257. SILVER, POTASSIUM, ETC. 19 First Series. 69. I05 69. 104 69. I03 69. I04 69. I02 Mean, 69.Io36, ~.0003 Second.Sries. 69. I05 69.0gg 69. 107 69. I03 69. 103 69. I05 69. I04 69.099 69. 1034 69.104 69. I03 69. I02 69. 104 69. I04 69. 105 69. Io3 69,IOI 60. I 05 69. Io3 Mean, 69. I033, 000.ooo3 Now, combining the three series, with their thirty experiments, we get the following: Marignac _ - 69.o62, +-.0017 Stas, Ist series _ 69. I 36, ~-.oo03 Stas, 2d series - _ 69. 1033, ~-.0003 General mean _ 69. Io32, +.0002 The quantity of silver chloride which can be formed from a known weight of potassium chloride has also been determined by Berzelius, Marignac, and Maumene. Berzelius* found that 100 parts of KCl were equivalent to 194.2 of *Poggend. Annal., 8, I: I 826. 20 THE ATOMIC WEIGHTS. AgCl; a value which, corrected for weighings in air, becomes 192.32. This experiment will not be included in our discussion. In 1842 Marignac* published two determinations, with these results from 100 KCl: I92.33 192.34 Mean, corrected for weighing in air, 192.26, ~.003 In 1846 Marignact published another set of results, as follows. The weighings were reduced to vacuum. The usual ratio is in the third column. I7.034 grm. KC1 gave 32.76I AgC1. 192.327 I4.427,, 27.749 " I92.34I 15.028 " 28.910 " I92.374 15.3 31, 29.102 " 92334 15.216,c 29.271 " I92.370 Mean, I92.349, 4-.oo6 Three estimations of the same ratio were also made by Maumene,4 as follows: 10.700 grm. KC1 gave 20.627 AgC1. I92.776 IO.5I95 " 20.273 I92.7I6 8.587,, I6.556 i I92.803 Mean, I92.765, -.017 The three series of ten experiments in all foot up thus: Marignac, 1842 ___-___ — ______ I192.260, +.003 " I846 -------------- I92.349, 4.oo6 Maumien6 _-_ I92.765, +-.017 General mean- ___. I92.294, ~.0029 These figures show clearly that the ratio which they represent is not of very high importance. It might be rejected altogether without impropriety, and is only retained for the * Ann. Chem. Pharm., 44, 21. I842. t Berzelius' Lehrbuch, 5th Ed., Vol. 3, pp. II92, II93. + Ann. d. Chim. ot d. Phys., (3,) I8, 4I. 1846. SILVER, POTASSIUM, ETC. 21 sake of completeness. It will obviously receive but little weight in our final discussion. In estimating the atomic weight of bromine the earlier experiments of Balard, Berzelius, Liebig, and Lwig may all be rejected. Their results were all far too low, probably because chlorine was present as an impurity in the materials employed. Wallace's determinations, based upon the analysis of arsenic tribromide, are tolerably good, but need not be considered here. In the present state of our knowledge, Wallace's analyses are better fitted for fixing the atomic weight of arsenic, and will, therefore, be discussed with refference to that element. The ratios with which we now have to deal are closely similar to those involving chlorine. In the first place there are the analyses of silver bromate by Stas.* In two careful experiments he found in this salt the following percentages of oxygen: 20.351 20.347 Mean, 20.349, ~.00I4 There are also four analyses of potassium bromate by Marignac.t The salt was heated, and the percentage loss of oxygen determined. The residual bromide was feebly alkaline. We cannot place much reliance upon this series. The results are as follows: 28.70I 6 28.6496 28.6050 28.7460 Mean, 28.6755, ~_.0207 When silver bromide is heated in chlorine gas, silver chloride is formed. In 1860 Dumast employed this method * Aronstein's Translation, pp. 200-206. t See E. Mulder's Overzigt, p. II7; or Berzelius' Jahresbericht, 24, 72. t Ann. Chem. Pharm., I I3, 20. 22 THE ATOMIC WEIGHTS. for estimating the atomic weight of bromine. His results are as follows: In the third column I give the weight of AgBr equivalent to 100 parts of AgCl. 2.028 grm. AgBr gave 1.547 AgC1. I31.092 4.237 3.235 " i30.974 5.769 4.403 131.024 Mean, I3I.030, -.023 This series is evidently of but little value. But the two ratios upon which, in connection with Stas' analyses of silver bromate, the atomic weight of bromine chiefly depends are those which connect silver with the latter element directly and silver with potassium bromide. Marignac,* to effect the synthesis of silver bromide, dissolved the metal in nitric acid, precipitated the solution with potassium bromide, washed, dried, fused, and weighed the product. The following quantities of bromine were found proportional to 100 parts of silver: 74.072 74.055 74.066 Mean, reduced to a vacuum standard, 74.077, -.003 Much more elaborate determinations of this ratio are due to Stas.t'In one experiment a known weight of silver was converted into nitrate, and precipitated in the same vessel by pure hydrobromic acid. The resulting bromide was washed thoroughly, dried, and weighed. In four other estimations the silver was converted into sulphate. Then a known quantity of pure bromine, as nearly as possible the exact amount necessary to precipitate the silver, was transformed into hydrobromic acid. This was added to the dilute solution of the sulphate, and, after precipitation was complete, the minute trace of an excess of silver in the clear supernatant fluid was determined. All weighings were re-' E. Mulder's Overzigt, p. i i6. Berzelius' Jahresbericht, 24, 72. t Aronstein's Translation, pp. I54-I70. SILVER, POTASSIUM, ETC. 20 duced to a vacuum. From these experiments, taking both series as one, we get the following quantities of bromine corresponding to 100 parts of silver: 74.0830 74.0790 74.0795 74.0805 74.0830 Mean, 74.08I, ~.ooo6 Combining this with Marignac's result, 74.077, ~.003, we get as a general mean the value 74.0809, 4-.0006.* The ratio between silver and potassium bromide was first accurately determined by Marignac.t I give, with his weighings, the quantity of KBr proportional to 100 parts of Ag: 2.131 grin. Ag -- 2.351 KBr. I 10.324 2.559 2.823 " I 10o. 316 2.447 2.700 " I 10.339 3.025 " 3-336 " 110.283 3.946 4-353 IIO.314 11.569 ",I 2.763 110.321.0. 120 " 22.191 " 110.293 Mean, corrected for weighing in air, I I0343, -.005 Stas,$ working in essentially the same manner as when he fixed the ratio between potassium chloride and silver, obtained the following results: * O. W. Huntington, in his paper upon the atomic weight of cadmium, (Amer. Acad. Proc., I88I,) gives three analyses and three syntheses of silver bromide. These give a fnean value of Ag: Br:: IOO: 74.064. This figure I record here in order that other chemists may not overlook the work of Mr. Huntington, although it came out too late for use in my own calculations. t E. Mulder's Overzigt, p. 116. Berzelius' Jahresbericht, 24, 72..t Aronstein's Translation, pp. 334-347. 24 THE ATOMIC WEIGHTS. 110.36I 110.360 110o.360 110.342 110.346 110.338 IIo.360 I 10.336 I 10.344 110.332 110.343 110.357 II0.334 110.335 Mean, 110.3463, --.0020 Combining this with Marignac's mean result, 110.343, -.005, we get a general mean of 110.3459, 4-.0019. The ratios upon which we must depend for the atomic weight of iodine are exactly parallel to those used for the determnination of bromine. To begin with, the percentage of oxygen in potassium iodate has been determined by Millon.* In three experiments he found: 22.46 22.49 22.47 Mean, 22.473, 4-.005 Millon also estimated the oxygen in silver iodate, getting the following percentages: I7.05 I7.o3 I7.o6 Mean, I7.047, _-.005 The analysis of silver iodate has also been performed with extreme care by Stas.t From 76 to 157 grammes were used:- Ann. d. Chim. et d. Phys., (3,) 9, 400. I843. - Aronsteins' Translation, pp. 179-200. SILVER, POTASSIUM, ETC. 25 in each experiment, the weights being reduced to a vacuum standard. As the salt could not be prepared in an absolutely anhydrous condition, the water expelled in, each analysis was accurately estimated and the necessary corrections applied. In two of the experiments the iodate was decomposed by heat, and the oxygen given off was fixed upon a weighed quantity of copper heated to redness. Thus the actual weights, both of the oxygen and the residual iodide, were obtained. In a third experiment the iodate was reduced to iodide by a solution of sulphurous acid, and the oxygen was estimated only by difference. In the three percentages of oxygen given below the result of this analysis comes last. The figures for oxygen are as follows: I6.976 I6.972 16.976I Mean, I6.9747, -.0009 This, combined with Millon's series above cited, gives us a general mean of 16.9771, Jz.0009. The ratio between silver and potassium iodide seems to have been determined only by Marignac,* and without remarkable accuracy. In five experiments 100 parts of silver were found equivalent to potassium iodide as follows: i.6i6 grm. Ag = 2.483 KI. Ratio, I53.65I 2.503 " 3.846 " " 153.665 3.427,, 5.268 " " 152.720 2. I41 " 3.290 " " I53.667 10.821 " I6.642 " " I53.794 Mean, 153.6994, 4-.0178 The synthesis of silver iodide has been effected by both Marignac and Stas. Marignac, in the paper above cited, gives these weighings. In the last column I add the ratio between iodine and 100 parts of silver: I5.000 grm. Ag gave 32.625 AgI. 117.500 I4.790,, 32. 170 117.512 18.545," 40.339 1" 17.519 Mean, corrected for weighing in air, II7.5335,.o0036 * Berzelius' Lehrbuch, 5th Ed., 3, II96. 21ii THE ATOMIC WEIGHTS. Stas* in his experiments worked after two methods, which gave, however, results concordant with each other and with those of Marignac. In the first series of experiments Stas converted a known weight of silver into nitrate, and then precipitated with pure hydriodic acid. The iodide thus thrown down was washed, dried, and weighed without transfer. By this method 100 parts of silver were found to require of iodine: II7.529 117.536 Mean, I17.5325, 4-.0024 In the second series a complete synthesis of silver iodide from known weights of iodine and metal was performed. The iodine was dissolved in a solution of ammonium sulphite, and thus converted into ammonium iodide. The silver was transformed into sulphate and the two soiutions mixed. When the precipitate of silver iodide was completely deposited the supernatant liquid was titrated for the trifling excess of iodine which it always contained. As the two elements were weighed out in the ratio of 127 to 108, while the atomic weight of iodine is probably a little under 127, this excess is easily explained. From these experiments two sets of values were deduced; one from the weights of silver and iodine actually employed, the other from the quantity of iodide of silver collected. From the first set we have of iodine for 100 parts of silver: I 7.5390 I I7.5380 117.5318 II7.5430 17.5420 117.5300 Mean, II7.5373, -.0015 From the weight of silver iodide actually collected we *-Aronstein's Translation, pp. I36, 152. SILVER, POTASSIUM, ETC. 27 get as follows. For experiment number three in the above column there is no equivalent here: 117.529 II7.53I II7.539 117.538 117.530 Mean, II7.5334,.I0014 Now, combining these several sets of results, we have the following general mean: Marignac _.11__ ___ __ 7.5335, -.0036 Stas, ISt series-_ _-_____ I 117.5325, -~-.0024 " 2d " 11___ ____ II7.5373, +-.00I5 " 3d. II7.5334, 4-.0OI4 General mean.._ _ 1 7.5345, _.0009 One other comparatively unimportant iodine ratio remains for us to notice. Silver iodide, heated in a stream of chlorine, becomes converted into chloride; and the ratio between these two salts has been thus determined by Berzelius and by Dumas. From Berzelius* we have the following data: In the ~third column I give the ratio between AgI and 100 parts of AgCl. 5.000 grinm. AgI gave 3.o62 AgC1. I63.292 12.212 "c 7.4755 " I63.360 Mean, I63.326, ~.023 Dumas't results were as follows: 3.520 grm. AgI gave 2. I149 AgC1. I63.793 7.01 " 4.28I," I63.770 Mean, I63.782, ~.oo8 General mean from the combination of both series, 163.733, 4-.0076. We now come to the ratios connecting sulphur with silver * Ann. d. Chim. et d. Phys., (2,) 40, 430. I829. tAnn. Chem. Pharm., II3, 28. I86o. 28 THE ATOMIC WEIGHTS. and chlorine. Other ratios have been applied to the determination of the atomic weight of sulphur, but they are hardly applicable here. The earlier results of Berzelius were wholly inaccurate, and his later experiments upon the synthesis of lead sulphate will be used in discussing the atomic weight of lead. Erdmann and Marchand determined the amount of calcium sulphate which could be formed from a known weight of pure Iceland spar; and later they made analyses of cinnabar, in order to fix the value of sulphur by reference to calcium and to mercury. Their results will be applied in this discussion towards ascertaining the atomic weights of the metals just named. For our present purposes only three ratios need be considered. First in order let us take up the composition of silver sulphide, as directly determined by Dumas, Stas, and Cooke. Dumas'* experiments were made with sulphur whicli had been thrice distilled and twice crystallized from carbon disulphide. A known weight of silver was heated in a tube in the vapor of the sulphur, the excess of the latter was distilled away in a current of carbon dioxide, and the resulting silver sulphide was weighed. I subjoin Dumas' weighings, and also the quantity of Ag,S proportional to 100 parts of Ag, as deduced from them: 9.9393 grm. Ag = I.473 S. Ratio, II114.820 9.962 " 1.4755 " I114.811 30.637 - 4.546.". I I4.838 30-936 " 4.586 ".. I I4-824 30.720 " 4.554 " 114.824 Mean, I 114.8234, --.0029 Dumas used from ten to thirty grammes of silver in each experiment. Stas,t however, in his work, employed from sixty to two hundred and fifty grammes at a time. Three of Stas' determinations were made by Dumas' method, while in the other two the sulphur was replaced by pure sulphu* Ann. Chem. Phann., II3, 24. I86o t Aronstein's Translation, p. 179. SILVER, POTASSIUM, ETC. 29 retted hydrogen. In all cases the excess of sulphur was expelled by carbon dioxide, purified with scrupulous care. Impurities in the dioxide may cause serious error. The five results come out as follows for 100 parts of silver: 114.854 114.853 II4.854 114.851 114.849 Mean, 114.8522, -.000ooo7 The experiments made by Professor Cooke* with reference to this ratio were only incidental to his elaborate researches upon the atomic weight of antimony. They are interesting, however, for two reasons: they serve to illustrate the volatility of silver, and they represent, not syntheses, but reductions of the sulphide by hydrogen. Cooke gives three series of results. In the first the silver sulphide was long heated to full redness in a current of hydrogen. Highly concordant and at the same time plainly erroneous figures were obtained; the error being eventually traced to the fact that some of the reduced silver, although not heated to its melting point, was actually volatilized and lost. The second series, from reductions at low redness, are decidedly better. In the third series the sulphide was fully reduced below a visible red heat. Rejecting the first series we have from Cooke's figures in the other two the subjoined quantities of sulphide corresponding to 100 parts of silver: 7.54II grm. Ag2S lost.9773 grm. S. Ratio, 114.889 5.0364 ".6524 " " I4.882 2.5815 3345 " " 1I4.886 2.6130.. 3387 " 1i4.892 2.5724 -3334 " " I 4.89I Mean, 114.888, -.oo12 I.I357 grm. Ag2S lost.1465 S. Ratio, 114.810 1.2936,.I670 " 114.823 Mean, I I4.8i65, 4-.0044 * Proc. American Acad. of Arts and Sciences, v. 12. i877. 30( THE ATOMIC WEIGHTS. Now, combining all four series, we get the following results: Dumas 114 _ I I4.8234, 4-.0029 Stas ____ — _______ —- -______ 114.8522, --.0007 Cooke's 2d ___ ____ 114.888, 4-.oo0012 " 3d___- ______ ------ 14.8165, -.0044 General mean- _____ 114.858I, ~.ooo6 Here again we encounter a curious and instructive compensation of errors, and another evidence of the accuracy of Stas. The percentage of silver in silver sulphate has been determined by Struve and by Stas. Struve* reduced the sulphate by heating in a current of hydrogen, and obtained these results: 5.I860 grm. Ag2SO4 gave 3.5910 grm. Ag. 69.244 per cent. 6.0543 " 4 1922 cc 69.243 8.6465 " 5.9858 " 69.228 II.6460 " 8.o608 " 69.215 9. I 090 " 6.3045 " 69.212 9.0669,, 6.2778, 69.239, Mean, 69.230, ~-.004 Stas,t working by essentially the same method, with from 56 to 83 grammes of sulphate at a time, found these percentages: 69.200 69.197 69.204 69.209 69.207 69.202 Mean, 69.203, +-.00I2 Combining this mean with that from Struve's series we get a general mean of 69.205, =t.0011. * Ann. Chem. Pharm., 80o, 203. I85I. t Aronstein's Translation, pp. 214-218. SILVER, POTASSIUM, ETC. 31 The third and last sulphur ratio with which we have now to deal is one of minor importance. When silver chloride is heated in a current of sulphuretted hydrogen the sulphide is formed. This reaction was applied by Berzelius* to determining the atomic weight of sulphur. He gives the results of four experiments; but the fourth varies so widely from the others that I have rejected it. I have reason to believe that the variation is due, not to error in experiment, but to error in printing; nevertheless, as I am unable to track out the cause of the mistake, I must exclude the figures involving it entirely from our discussion. The three available experiments, however, give the following results: The last column contains the ratio of silver sulphide to 100 parts of chloride. 6.6075 grm. AgCl gave 5.7I5 grm. Ag2S. 86.478 9.2323 7.98325 " 86.471 10. 1775 8.80075 " 86.472 Mean, 86.4737, 4-.00I5 We have also a single determination of this value by Svanberg and Struve.t After converting the chloride into sulphide they dissolved the latter in nitric acid. A trifling residue of chloride, which had been enclosed in sulphide, and so protected against change, was left undissolved. Hence a slight constant error probably affects this whole ratio. The experiment of Svanberg and Struve gave 86.472 per cent. of silver sulphide derived from 100 of chloride. If we assign this figure equal weight with the results of Berzelius, and combine, we get a general mean of 86.4733, =.0011. For sodium there are but two ratios of any definite value for present purposes. The early work of Berzelius we may disregard entirely, and confine ourselves to the consideration of the results obtained by Penny, Pelouze, Dumas, and Stas. * Berzelius' Lehrbuch, 5th Ed., Vol. 3, p. I I87. t Journ. fur Prakt. Chem., 44, 320. I848. 32 THE ATOMIC WEIGHTS. The percentage of oxygen in sodium chlorate has been determined only.by Penny,* who used the same method which he applied to the potassium salt. Four experiments gave the following results: 45.060 45.075 45.080 45.067 Mean, 45.o0705, --.0029 The ratio between silver and sodium chloride has been fixed by Pelouze, Dumas, and Stas. Pelouzet dissolved a weighed quantity of silver in nitric acid, and then titrated with sodium chloride. Equivalent to 100 parts of silver he found of chloride: 54. I58 54.125 54.139 Mean, 54. I4I, -.00o63 By Dumast we have seven experiments, with results as follows: The third column gives the ratio between 100 of silver and NaCl. 2.0535 grm. NaC1 = 3.788 grmin. Ag. 54.211 2. I69 " 4.0095 " 54.097 4.3554 " 8.o425 " 54.155 6.509 12.0140 " 54.178 6.413 " II.8375 " 54-I75 2. I1746 " 4.012 " 54.202 5.11 I3 9.434 " 54. 187 Mean, 54. 72, --.0096 Stas,ll applying the method used in establishing the similar ratio for potassium chloride, and working with salt from * Phil. Transactions, I839, p. 25. t Compt. Rend., 20, 1o47. I845. Ann. Chem. Pharm., 1 3, 31 I886o. 11Aronstein's Translation, p. 274. SILVER, POTASSIUM, ETC. 33 six different sources, found of sodium chloride equivalent to 100 parts of silver: 54.2093 54.2088 54.2070 54.2070 54.2070 54.2060 54.2076 54.2081 54.2083 54.2089 Mean, 54.2078, ~.0002 Now, combining these three series, we get the following result: Pelouze-_____ -_-_ -___-_-_- __ 54. 4I, oo.0063 Dumas _______________ 54.1 I72, -.oog6 Stas-.________-_............. 54.2078, -.0002 General mean ______-__ 54.2076, ~-.0002 Here the work of Stas is of such superior excellence that the other series might be completely rejected without appreciably affecting our calculations. We have now before us the data establishing, with greater or less accuracy, twenty different ratios relating to the atomic weights of the seven elements under discussion. In these we are to discuss the results of about two hundred and fifty separate experiments. Before beginning upon our calculations we will tabulate our ratios, and number them for convenient future reference. Of course it will be understood that the probable errors given below relate to the last term of each proportion: (I.) Percentage of O in KC103 39.I54, ~.00038 (2.) cc KBrO ___ 28.6755, ~.0207 (3.) 03 ________ 22.473, ~.0050 (4.). NaC103 _ 45.0705, -.0029 (5.) it d AgC103 ________ 25.0795, 4-.OOIO (6.) AgBrO ____ 20.349, -.I004 (7.).. AgIO ______ 6.977I, +.0009 (8.) Ag in Ag2SO4 69.205,.OOII00 3 34 THE ATOMIC WEIGHTS. (9.) Ag: NaC1:: 100: 54.2076, -.0002 (Io. ) Ag: KC1:: Ioo: 69. I032, -.ooo2 (ii.) Ag: Kr r:: Ioo: 110.3459, -.oo0019 (12.) Ag: KI:: Ioo: I53.6994,'.0178 (I3.) Ag: C1:: Ioo: 32.8418, o.ooo6 (14.) Ag: Br:: oo: 74.0809, ~.0006 (I5.) Ag: I:: Ioo: II7.5345, 4-.0009 (I6.) Ag: Ag2S:: Ioo: II4.8581, ~-.0006 (I7.) KC1: AgC1:: IOO: I92.294, -.0029 (I8.) AgCl: AgBr:: Ioo: 131.030, -.023 (I9.) AgCl: AgI:: Ioo: I63-733, -.0076 (20.) AgCl: Ag,S:: Ioo: 86.4733, -.0oo0 Now, from ratios 1 to 7 inclusive, we can at once, by applying the known atomic weight of oxygen, deduce the molecular weights of seven haloid salts. Let us consider the first calculation somewhat in detail. Potassium chlorate yields 39.154 per cent. of oxygen and 60.84(6 per cent. of residual chloride. For each of these quantities the probable error is +.00038. The atomic weight of oxygen is 15.9633, i.0035, so that the value for three atoms becomes 47.8899, ~4.0105. We have now the following simple proportion: 39.154: 60.846:: 47.8899: ~x, the molecular weight of potassium chloride, - 74.4217. The probable error being known for the first, second, and third term of this proportion, we can easily find that of the fourth term by the formula given in our introduction. It comes out 4-.0164. By this method we obtain the following series of values, which may conveniently be numbered consecutively with the foregoing ratios: (21.) KC1, from (I,) 74.42I7, ~.o064 (22.) KBr, " (2,) II9.II7, o.0962 (23.') KI, (3,)- 165.210,.0529 (24.) NaC1, "(4,)- 58-366, -. 0137 (25.) AgC1, " (5,)= 143.062, -.0320 (26.) AgBr," (6,)- I87-453, --.0432 (27.) AgI, " (7,). 234.195, ~-.0530 With the help of these molecular weights we are now able to calculate eight independent values for the atomic weight of silver: SILVER, POTASSIUM, ETC. 35 First, from (IO) and (21,) Ag 107.696, 4-.024 Second, " (II) " (22,) " I07.948, 4-.o87 Third, " (2) " (23,) " — I07.488, +.037 Fourth, " (9) " (24,) " I07.67I, -.025 Fifth, " (13) " (25,) " I07.694, 4-.024 Sixth, " (14) " (26,) "- 107.68I, 4-.025 Seventh, " (I5) " (27,) " I07.659, 4-.024 Eighth, "(8) () (6,) " 107.712, -.025 General mean, " 10 I7.675,.o0096 It is noticeable that six of these values agree very well. The second and third, however, diverge widely from the average, but in opposite directions; they have, moreover, high probable errors, and consequently little weight. Of these two, one represents little and the other none of Stas' work. Their trifling influence upon our final results becomes curiously apparent in the series of silver values given a little further along. When we consider closely, in all of its bearings, any one of the values just given, we shall see that for certain purposes it must be excluded from our general mean. For example, the first is derived partly from the ratio between silver and potassium chloride. From this ratio, the atomic weight of one substance being known, we can deduce that of the other. We have already used it in ascertaining the atomic weight of silver, and the value thus obtained is included in our general mean. But if froni it we are to determine the molecular weight of potassium chloride, we must use a silver value derived from other sources only, or we should be assuming a part of our result in advance. In other words, we must now use a general mean fvr silver from which this ratio with reference to silver has been rejected. Hence the following series of silver values, which are lettered for reference: A. General mean from all eight -_ —_. —--- I107.675, +.0o96 B. "c rejecting the first _.__-___ 107.671, -.0105 C. " d " second _____ I07.67I, ~.0097 D. " " third -—.6... I07.679, +-.000 E. " " fourth ------- I07.675, ~-.0104 F. " " fifth.______ I107.671, +-.0105 G. " " sixth __ __ 107.674, ~+.0104 H. " " seventh ____ I07.678, -.0105 I. c" "s eighth- ___ I07.679, -.0104 36 THE ATOMIC WEIGHTS. These values are essentially the same, both in magnitude and in weight. For all practical purposes any one of them is as good as any other. Still, on theoretical grounds, it may be well to keep them distinct and separate in the remainder of this discussion. We are now in a position to determine more closely the molecular weights of the haloid salts which we have already been considering. For silver chloride, still employing the formula for the probable error of the last term of a proportion, we get the following values: From (5) —- _______- AgCl = 143.062, -.032 From (I3) and (F) ___ 143.032, -+.a14 From (I7) and (21)...___.. " I43 i08, -.034 From (i8) and (26) ___ " I43.06I, -.041 From (I9) and (27)___, -- - I43-035, -.033 General mean.__ " I43.045, +-.oio8 Subtracting from this the atomic weight of silver, 107.675, 4-.0096, we get for the atomic weight of chlorine, Cl 35.370, -t.014. For silver bromide we have these results: From (6) _____AgBr = I87.453, ~.043 From (14) and (G) ____ I87.440, -.oi8 From (I8) and (25).... " I87-454,.053 General mean _-__ " I87.443, -.oi6 Hence, using the general mean for silver as above, Br = 79.768, i.019. Silver iodide comes out as follows: From (7) ---..AgI = 234.I95, -.053 From (I5) and ().. —----- " = 234.237, --.023 From (I9) and (25).____ " = 234.240, --.054 General mean..____ " _ 234.232, ~-.1Og9 Hence I = 126.557, 4-.022. For the molecular weight of sodium chloride we have: From (4) —----- _____NaC = 58.366, -.o0137 From (9) and (E) _-', =58.368, -.0056 General mean __. " 58.3676, ___.0052 SILVER, POTASSIUM, ETC. 37 Hence, if chlorine = 35.370, i:.014, then Na = 22.998, +.011. For potassium chloride: From (I)_-____.____. KC1 = 74.4217, -.OI6 From (Io) and (B) __ " — 74-404I, +.007 From (I7) and (25)_.__ — " 74.3975, - 017 General mean _.__ " = 74.4057, o.oo62 For potassium bromide we get: From (2) __________KBr- II9.I7,.o96 From (II) and (C) ------ " II8.8IO, 4-.oI8 General mean —- " =I8.815, -.011O7 And for potassium iodide: From (3) - - _KI 165.210, -.053 From (12) and (D).___ " i- 165.502, ~.029 General mean ___ " = 65.432,.o026 Now, taking the molecular weights of these three potassium salts in connection with the atomic weights just found for chlorine, bromine, and iodine, we get these values for potassium: From the chloride _-K__ -- 39.o036, +.oi6 From the bromide _ " = 39.047, ~.022 From the iodide-_ __ 38.875, ~.o34 General mean _ —--- 39 Ig9, -.oI2 Finally, the three sulphur ratios give us three estimates for the atomic weight of sulphur. In the tllirl of these I have applied the "A" value for silver and the general mean for silver chloride: From (8) and (I)J S..__._S 3I.968, 4-.014 From (I6) and (I) ____ " - 31.995, 4-.032 From (20)______ " 32.041, -.028 General mean _____ —-- --- 31.984, -.I02 We may now appropriately compare the results of this 38 THE ATOMIC WEIGHTS. discussion with the atomic weights deduced by Stas from his own experiments only. His values are given under two headings: one for oxygen 16C), the other for O — 15.96. As we have been using the figure 15.9633 for oxygen, here is at the outset a discrepancy. Starting from this value we found: Ag _ I07.675, ~.oo96 C1.. 35.370, -.014 Br _ 79.768, -.oI9 I =126.557, i-.022 Na = 22.998, i-.OII K 39.oi9,.012 S 31.984, -4-.612 If we assume 16 to be the true figure for oxygen, we get the following results, which I have placed in a column parallel with the values Iound by Stas: The New Values. Stas. Dilferences. Silver _ —------ I07.923 10o7930.007 Chlorine _-_- _ 35-451 35.457.oo6 Bromine _ 79.951 79.952.OOI Iodine _______ 1 26.848 126.850.002 Sodium _..-_..._ 23.051 23.043.009 Potassium _ 39. 109 39. I37.028 Sulphur-.... 32.058 32.074.oi6 These differences are insignificant. No other criticism could more severely test the character of Stas' work, or more definitely illustrate his magnificent accuracy of mnanipulation. NITROGEN. 39 NITROGEN. The atomic weight of nitrogen has been determined from the density of the gas, from the ratio between ammoniuml chloride and silver, and from the composition of certain nitrates. Upon the density of nitrogen a great many experiments have been made. In early times this constant was determined by Biot and Arago,'homson, Dulong and Berzelius, Lavoisier, and others. But all of these investigations may be disregarded as of insufficient accuracy; and, as in the case of oxygen, we need consider only the results obtained by Dumas and Boussingault, and by Regnault. Taking air as unity, Dumas and Boussingault* found the density of nitrogen to be-.970.972 -974 Mean,.972, 4.00078 For hydrogen, as was seen in our discussion of the atomic weight of oxygen, the same investigators found a mean of.0693, 14-.00013. Upon combining this with the above nitrogen mean, we find for the atomic weight of the latter element, N 14.026, i.0295. By Regnaultt much closer work was done. He found the density of nitrogen to be as follows:.97148.97148.97154.97155.97Io8.97108 Mean,.97137, -4-.o00o0062 *Compt. Rend., 12, 1005. I841. t Compt. Rend., 20, 975. I845. 40 TI-E ATOMIIC WEIGHTS. For hydrogen, Regnault's mean value is.069263, i.000019. Hence, combining as before, N -- 14.0244, i.0039.* The value found by combining both series of experiments is N - 14.0244, iL.0039. In discussing the more purely chemical ratios for establishing the atomic weight of nitrogen, we may ignore, for the present, the researches of Berzelius, of Anderson, and of Svanberg. These chemists experimented chiefly upon lead nitrate, and their work is consequently now of greater value for fixing the atomic weight of lead. Their results will be duly considered in the proper connection further on. The ratio between ammonium chloride and silver has been determined by Pelouze, by Marignac, and by Stas. The method of working is essentially that adopted in the similar experiments with the chlorides of sodium and potassium. For the ammonium chloride equivalent to 100 parts of silver, Pelouzet found: 49.556 49.517 Mean, 49.5365, ~.013 Marignaci obtained the following results. The usual ratio for 100 parts of silver is given also: S.o63 grm. Ag = 3.992 grinm. NH4C1. 49.5I0 9.402 " 4.656 "s 49.521 10o. 339 5. I20, 49.52i I2.497 6. I9I " 49-540 II.337 5.617 " 49-546 1I-307 5.595 49-483 4.326 " 2. I43 49-538 AMean, 49.523, -~.0055 " Professor Le Conte, in his corrections of Regnault's calculations, already cited in a foot note to the chapter on oxygen, finds for the density of nitrogen the value 0.971346. Hence N -- 14.0225. This correction is very slight, but it should be considered in any future revision of the atomic -weights. f Compt. Rend., 20, Io047. J845. 4 Berzelius' Lehrbuch, 5th Ed., 3(l v., II84, II85. NITROGEN. 41 But neither of these series can for a moment compare with that of Stas.* He used from 12.5 to 80 grammes of silver in each experiment, reduced his weighings to a vacuum standard, and adopted a great variety of precautions to ensure accuracy. He found for every 100 parts of silver the following quantities of.NI4C1: 49.600 49-599 49.597 49.598 49-597 49-593 49.597 49-5974 49.602 49-597 49.598 49.592 Mean, 49.5973, ~-.0005 Now, combining these three series, we get: Pelguze__- _ _______ 49.5365, 4-.013 Marignac -__ —— ____-__ -_ - -_ 49.523, 4-.0055 Stas __- _ 49.5973, -.0005 General mean __._ 49.597, ~.0005 Thle quantity of silver nitrate which can be fornied from a known weight of metallic silver has been determlined by P'enny, by Marignac, and by Stas. Pennyt dissolved silver in nitric acid in a flask, evaporated to dryness witliout transfer, and weighed. One hundred parts of silver thus gave of nitrate: I57.430 I57.437 I57.458 157.440 I57.430 I57.455 Mean, 157.4417, -.0033 * Aronstein's Translation, pp. 56-58. - Phil. Trans., 1839. 42 THE ATOMIC WEIGHTS. Marignac's* results were as follows. In the third column they are reduced to the common standard of 100 parts of silver: 68.987 grm. Ag gave io8.6o8 grm. AgNO,. 157-433 57.844 " 91-047 " 157.401 66.436 " 104.592 " 157-433 70.340 "i Io. 718 1" 57-404 200.000 " 314.894 " I57-447 Mean, I57.4236, -.006I Stas,t employing from 77 to 405 grammes of silver in each experiment, made two different series of determinations at two different times. The silver was dissolved with all the usual precautions against loss and against impurity, and the resulting nitrate was weighed, first after long drying without fusion just below its melting point; and again, fused. Between the fused and the unfused salt there was in every case a slight difference in weight, the latter giving a maximum and the former a minimum value. In Stas' first series there are eight experiments; but the seventh he himself rejects as inexact. The values obtained for the nitrate from 100 parts of silver are given below in two columns, representing the two conditions in which the salt was weighed. The general mean given at the end I have deduced from the means of the two columns considered separately: Unfused. Fused. 157.492 157.474 157.510 I57.48I 157.485 157.477 I57.476 I57.47I I57.478 I57.470 157.47I I57.463 I57.488 157.469 Mean, I57-4857 Mean, 157.472 General mean, 157.474, ~-.0014 * Berzelius' Lehrbuch, 5th Ed., 3, pp. 1184, Ii85. t Aronstein's Translation, pp. 305 and 315. NITROGEN. 43 In the later series there are but two experiments, as follows: Uifused. Fused. I57.4964 157.488 157.4940 157.480 Mean, I57-4952 Mean, I57-484 General mean, I 57.486, +.0003 Now, to comnbine all four sets of results: Penny _ __ I57.4417, -.0033 Marignac- I57.4236, ~.oo6I Stas, Ist series _ I57.4740, ~.00o4 Stas, 2d series..- I57.4860, -.0003 General mean I-57.479, -.0003 For the direct ratio between silver nitrate and silver chloride there are two series of estimations. A weighed quantity of. nitrate is easily converted into chloride, and the weight of the latter ascertained. In two experiments Turner* found of chloride from 100 parts of nitrate: 84-357 84-389 Mean, 84.373, -- 0oI Penny,t in five determinations, found the following percentages: 84.370 84.388 84-377 84.367 84-370 Mean, 84.3744, i-.0025 The general mean from both series is 84.3743, -.0025. The ratio directly connecting silver nitrate with ammonium chloride has been determined only by Stas.t The * Phil. Trans., I833, 537. -i Phil. Trans., I839. + Aronstein's Translation, p. 309. 44 THE ATOMIC WEIGHTS. usual method of working was followed; namely, nearly equivalent quantities of the two salts were weighed out, the solutions mixed, and the slight excess of one estimated by titration. In four experiments 100 parts of silver nitrate were found equivalent to chloride of ammonium as follows: 31.489 31.490 31.487 31.486 Mean, 3 I.488, --.ooo6 The similar ratio between potassium chloride and silver nitrate has been determined by both Marignac and Stas..Marignac* gives the following weights. I add the quantity of KC1 proportional to 100 parts of AgNO,: I.849 grm. KC1- 4.218 grm. AgNO3. 43.836 2.473 5.640 " 43.848 3.3I7 7.565 " 43.847 2.926,, 6.670 43.868 6. I9I " I4. I 1 " 43. 877 4.351', 9.9I8 43.870 Mean, 43.858, -.0044 Stas't results are given in three series, representing silver nitrate from three different sources. In the third series the nitrate was weighed in vacuo, while for the other series this correction was applied in the usual way. For the KC1 equivalent to 100 parts of AgNO3 Stas found: Fi-st Series. 43-878 43.875 43.875 43.874 Mean, 43.8755, -.0005 * Berzelius' Lehrbuch, 5th Ed., 3d vol., I I84, I I85. t Aronstein's Translation, p. 308. NITROGEN. 45 Second Series. 43.864 43.869 43.876 Mean, 43.8697, -.0023 Third Series. 43-894 43-878 43-885 Mean, 43.8857, 4-.003I Combining all four series we have: Marignac __ - 43.858, -.0044 Stas, Ist series _ 43.8755, ~-.oo05 " 2d " -43.8697, -.0023 "3d " -43.8857, 4-.0031 General mean — _ 43.87I5, -.0004 There have also been determined by Penny and by Stas a series of ratios connecting the alkaline chlorides and chlorates with the corresponding nitrates. One of these, relating to the lithium salts, will be studied further on with reference to that metal. The general method of working upon these ratios is due to Penny.* Applied to the ratio between the chloride and nitrate of potassium it is as follows: A weighed quantity of the chloride is introduced into a flask which is placed upon its side and connected with a receiver. An excess of pure nitric acid is added, and the transformation is gradually brought about by the aid of heat. Then, upon evaporating to dryness over a sand bath, the nitrate is brought into weighable form. The liquid in the receiver is also evaporated, and the trace of solid matter which had been mechanically carried over is recovered and also taken into account. In another series of experiments the nitrate was taken, and by pure hydroch1ric acid converted into chloride; the process being the same. In the following columns of figures I *Phil. Trans., 1839. 46 TIHE ATOMIC WEIGHTS. have reduced both series to one standard; namely, so as to express the number of parts of nitrate corresponding to 100 of chloride: First Series. -KCl treated with HVNO3. 135.639 I35.637 I35.640 I35.635 135.630 135.640 135.630 Mean, 135.636, +.ooII Second Series. -KNVO3 treated with HC1. I35.628 I35.635 I35.630 I35.641 135.630 135.635 I35.630 Mean, 153.633, -.o001I Stas* results are as follows: I35.643 I35.638 135.647 135.649 I35.640 135.645 135.655 Mean, I35.6453, -O.0014 These figures by Stas represent weighings in the air. Reduced to a vacuum standard this mean really becomes 135.6423. Now, combining, we have: Penny, Ist series __ __ I35.636, ~-.ooI " 2d " - _ - ___ I135.633, ~-.OOI Stas _ —__1-____- __ —- ------ 135.6423, -.0014 General mean ____ I35.6363, -~.0007 * Aronstein's Translation, p. 270. NITROGEN. 47 By the same general process Penny* determined how much potassium nitrate could be formed from 100 parts of chllorate. He found as follows: 82.505 82.497 82.498 82.500 Mean, 82.500, ~-.0012 For 100 parts of sodium chlorate ihe found of nitrate: 79.875 79.882 79.89o Mean, 79.8823, -.0029 For the ratio between the chloride and nitrate of sodium Penny made two sets of estimations as in the case of potassium salts. The subjoined figures give the amount of nitrate equivalent to 100 parts of chloride: first Series. -Na C6 treated.with HANO3. I45.415 145.408 I45.420 I45.424 145.410 145.418 145.420 Mea.n, I45.4I64, 4-.0015 Second Series. —NaX03 treated witht HCl. 145.419 145.391 I45.412 I45.415 I45.412 145.412 Mean, I45.4I0, 4-.0026'Phil. Trans., 1839. 48 THE ATOMIC WEIGHTS. Stas* gives the following series: I45.453 I45.468 145.465 145.469 I45,443 Mean, after reducing to vacuum standard, 145.4526, -.0030 Combining, we have as follows: Penny, Ist series _ —_____-__ I145.4164, -.OOI5 " 2d " 145.410, _.0026 Stas _.-..__-__ __-. __.___ —-- 145.4526, -4-.0030 General mean............ 45.4185,.oo0012 We have now, apart from the determinations of gaseous density, nine ratios, representing one hundred and fourteen experiments from which to calculate the atomic weight of nitrogen. Let us first collect and number these ratios: (I.) Ag: AgNO3:: oo: 157.479, ~.0003 (2.) AgNO,: AgCl:: ao:: 84.3743, +.0025 (3.) AgNO3: KC:: 100: 43.8715, ~.0004 (4.) AgNO3: NH4C1:: 1oo: 31.488, +.ooo6 (5.) Ag: NH4Cl:: Ioo: 49.597, --.0005 (6.) KC1: KNO3:: Ioo: I35.6363, 4.0007 (7.) KC10,3: KNO3:: loo: 82.500, ~.0012 (8.) NaC1: NaNO3:: 100: 145.4185, 4-.oo02 (9.) NaC103: NaNO3:: 0: 79.8823, +-.0029 From these ratios we are now able to deduce the molecuilar weight of ammonium chloride and of the three nitrates named in them. For these calculations we may use the already determined atomic weights of silver, oxygen, potassium, sodium, and chlorine, and the molecular weights of silver chloride and sodium chloride. These two molecular weights involve, respectively, the most probable values for silver, sodium, and chlorine. We cannot, however, appropriately use the directly determined molecular weight of potassium chloride, since the most probable value for the' Aronstein's Translation, p. 278. NITROGEN. 49 atomic weight of potassium is only in part derived from that salt. The following are the values which we shall employ: Ag = 107.675, ~.0096 K =- 39.019, -.oI2 Na = 22.998, 4-.OI1 C1 35-370, --.04 03 -- 47.8899, ~.0105 AgCl I43.045, -'oIo8 NaC - 58.3676, ~.0052 Now, from ratio number five we can get the molecular weight of ammonium chloride, NH4Cl = 53.4048, 4-.0048, and N = 14.0336, i.0153. From ratio number four an independent value for nitrogen can be calculated, namely, N - 14.0330, -+-.015. For the molecular weight of silver nitrate three values are deducible, namely: From (I) _ _-__ _.__.AgNO3 = 169.5655, -.oI5I From (2)____ _ " I69.5362,.0138 From (3)= _____ ___ " 169.5612, ~-.0429 General mean " = 169.5489, -.0099 Hence N = 13.9840, ~+.0174. The molecular weight of potassium nitrate is twice calculable, as follows: From (6) ____.. KNO -- I00.8985, 4-.0255 From (7)________ " = o00.88oI, -4-.0178 General mean__ " _ 00.8863, -~-.0146 And N =- 13.9774, +.0216. So also for sodium nitrate we have: From (8) ----— ____ NaNO, = 84.8773, -.0076 From (9)- " = 84.8809, T.0099 General mean__ " 84.8785, 4.oo60 And N = 13.9906, 4-.0163. We have now before us six estimates of the atomic weight of nitrogen. It only remains for us to combine these after 4 50 THIE ATOMIC WEIGHTS. the usual method, as follows, in order to obtain the most probable value: I. From specific gravity of N -__ - N 1 I4.0244, 4-.0039 2. " ammonium chloride-___- ____- " I4.0336, i.0153 3. " ratio number four_____ " I4.0330, -.0150 4. " silver nitrate ____ __" I3.9840, ~.0174 5. " potassium nitrate13 ____" I39774, --.02I6 6. sodium nitrate ____- -__-_ " - I3.9906, ~.o063 General mean.. -_ _ _1_ __ 4.0210, --.0035 -If oxygen is 16, this becomes 14.0291. Stas found N14.044. The difference is.015, showing a remarkably close agreement. CARBON. Although there is a large mass of material relating to the atomic weight of carbon, much of it may be summarily set aside as having no value for present purposes. The density of carbon dioxide, which has been scrupulously determined by many investigators,* leads to no safe estimate of the constant under consideration. The numerous analyses of hydrocarbons, like the analyses of naphthalene by Mitscherlich, Woskresensky, Fownes, and Dumas, give results scarcely more satisfactory. In short, all the work done upon the atomic weight of carbon before the year 1840 may be safely rejected as unsuited to the present requirements of exact science. As for methods of estimation we need consider but three, as follows: First.-The analysis of organic salts of silver. Second.-The determination of the weight of carbon dioxide formed by the combustion of a known weight of carbon. * Notably by Lavoisier, Biot and Arago, De Saussure, Dulong and Berzelius, Buff, Von Wrede, Regnault, and Marchand. For details, Van Geuns' monograph may be consulted. CARBON. 51 Third.-The method of Stas, by the combustion of carbon monoxide. The first of these methods, which is also the least accurate, was employed by Liebig and Redtenbacher* in 1840. They worked with the acetate, tartrate, racemate, and malate of silver, making five ignitions of each salt, and determining the percentage of metal. From one to nine grammes of material were used in each experiment. In the acetate the following percentages of silver were found: 64.615 64.624 64.623 64.614 64.6Io Mean, 64.6172, ~-.ooi8 After applying corrections for weighing in air this mean becomes 64.6065. In the tartrate the silver came out as follows: 59.297 59.299 59.287 59.293 59.293 Mean, 59.2938, - 00oo4 Or, reduced to a vacuum, 59.2806 In the racemate we have: 59.290 59.292 59.287 59.283 59.284 Mean, 59.2872, ~.0012 Or, corrected, 59.2769 *Ann. Chem. Pharm., 38, I37. Mem. Chem. Soc., I, 9. Phil. Mag., (3,) 19, 2IO. 52 THE ATOMIC WEIGHTS. And from the malate: 61.996 61.972 62.015 62.059 62.011 Mean, 62.0106, -.0096 Or, corrected, 62.00I6 Now, applying to these mean results the atomic weights already found for oxygen and silver, we get the following values for carbon: From the acetate ____C - 2.0306, ~-.0047 " tartrate — __ I12.0356, 4-.0064 " racemate __,, _ " --- I2.0413, +-.0063 malate -.__- ",, — 12.0408, -.0054 General mean- __ "-= I2.0363, ~-.0028 Now these results, although remarkably concordant, are by no means unimpeachable. They involve two possible sources of constant error, namely, impurity of material and the volatility of the silver. These objections have both been raised by Stas, who found that the silver tartrate, prepared as Liebig and Redtenbacher prepared it, always carried traces of the nitrate, and that he, by the ignition of that salt, could not get results at all agreeing with theirs. In the case of the acetate a similar impurity would lower the percentage of silver, and thus both sources of error would reinforce each other and make the atomic weight of carbon come out too high. With the three other salts the two sources of error act in opposite directions, although the volatility of the silver is probably far greater in its influence than the impurity. Even if we had no other data relating to the atomic weight of carbon, it would be clear from these facts that the results obtained by Liebig and Redtenbacher must be decidedly in excess of the true figure. A different method of dealing with organic silver salts was adopted by Maumene,* in 1846, for the purpose of estab*Ann. d. Chim. et d. Phys., (3,) 18, 41. CARBON. 53 lishing, by reference to carbon, the atomic weight of silver. We will simply reverse his results and apply them to the atomic weight of carbon. He effected the combustion of the acetate and the oxalate of silver, and, by weighing both the residual metal and the carbon dioxide formed, he fixed the ratio between these two substances. In the case of the acetate his weighings show that for every gramme of metallic silver the weights of CO2 were produced, which are shown in the third column: 8.083 grm. Ag = 6.585 grm. CO2..8147 11.215 9.I35 ".8136 I4-351 " II.6935 ".8148 9.030 " 7.358 ".8148 20.227': I6.475 ".8145 Mean,.81448 The oxalate of silver, ignited by itself, decomposes too violently to give good results; and for this reason it was not used by Liebig and Redtenbacher. Maumene, however, found that when the salt was mixed with sand the combustion could be tranquilly effected. The oxalate employed, however, with the exception of the sample represented in the last experiment of the series, contained traces of nitrate, so that these results involve slight errors. For each gramme of silver the appended weights of C02 were obtained: I4.299 grm. Ag - 5.835 grm. C02..408I I7-754 7.217,.4059 II.550 " 4.703.4072 1o.771 4-387.4073 8.674 " 3.533 " -4073 114355 4.658 ".4073 Mean,.407I8 Now, one of these salts being formed by a bivalent and the other by a univalent acid, we have to reduce both to a common standard. Doing this, we have the following results for the ratio between the atomic weight of silver and the molecular weight of CO,; if Ag = 1.00, 54 THE ATOMIC WEIGHTS. From the acetate, CO2 =.40724, ~_.000076 " oxalate, —.40718, 4-.oooi85 General mean, " -.40723, 4-.000071 Here the slight error due to the impurity of the oxalate becomes of such trifling weight that it practically vanishes. From these data, if Ag = 107.675, 4-.0096, CO2 - 43.8485, __.0086. Hence C - 11.9219, -.0111. As has already been said, the volatility of silver renders all the foregoing results more or less uncertain. Far better figures are furnished by the combustion of carbon directly, as carried out by Dumas and Stas* in 1840 and by Erdmann and Marchandt in 1841. In both investigations weighed quantities of diamond, of natural graphite, and of artificial graphite were burned in oxygen, and the amount of dioxide produced was estimated by the usual methods. The graphite employed was purified with extreme care by treatment with strong nitric acid and by fusion with caustic alkali. I have reduced all the published weighings to a common standard, so as to show in the third column the amount of oxygen which combines with a unit weight (say one gramme) of carbon. Taking Dumas and Stas' results first in order we have from natural graphite: I.ooo grm. C gave 3.67I grm. CO2. 2.6710.998 " 3.660 " 2.6673.994 "6 3.645 " 2.6670 1.216 "c 4.46I " 2.6686 1.471 " 5.395 " 2.6676 Mean, 2.6683, ~-.0005 With artificial graphite:.992 grm. C gave 3.642 grm. CO2. 2.6714.998 3.662 2.6682 I.66o " 6.o85 " 2.6654 1.465 " 5-365 2.6744 Mean, 2.66985, 4-.0013 * Compt. Rend., TI, 99-oo008. Ann. Chim. Phys., (3,) I, I. t-Journ. f. Prakt. Chem., 23, 159. CARBON. 55 And with diamond:.708 grm. C gave 2.598 grm. CO2. 2.6695.864 " 3. I675 " 2.666i 1.219 " 4.465 " 2.6628 1.232 " 4.519 " 2.6680 1.375 " 5.04 " 2.6662 Mean, 2.6665, -.0007 Erdmann and Marchand's figures for natural graphite give the following results: 1.5376 gnm. gave 5.6367 grm. CO2. 2.6659 I.6494 " 6.0384 " 2.6609 1.4505 " 5-3I575 " 2.6647 In one experiment 1.8935 grm. of artificial graphite gave 6.9355 grm. CO2. Ratio for 0, 2.6628. This, combined with the foregoing series, gives a mean of 2.6636, ~+.0007. With diamond they found:.8052 grm. gave 2.9467 grm. CO2. 2.6596.0o858 " 3.9875 " 2.6632 I13557 4.9659 " 2.6629 I.6305 " 5.97945 " 2.6673.7500 " 2.7490 " 2.6653 Mean, 2.6637, 4-.0009 Now, combining all these series, we get the following result: Dumas and Stas, Ist set _-______ 2.6683, 4-.0005 9" 2d" _ 2.66985, 4-.0013 " 3d" _ _.._ 2.6665, ~-.0007 Erdmann and Marchand, Ist__... 2.6636, -.0007 zd -- 2.6637, ~.0009 General mean _.....__ 2.66655, -4-.0003 Hence, if 0 = 15.9633, +-.0035, C - 11.973, ~ —.0030. Another very exact method for determining the atomic weight of carbon was employed by Stas* in 1849. Carefully purified carbon monoxide was passed over a known weight * Bull. Acad. Bruxelles, 1849, (I,) 31. 56 THE ATOMIC WEIGHTS. of copper oxide at a red heat, and both the residual metal and the carbon dioxide formed were weighed. The weighings were reduced to a vacuum standard, and in each experiment a quantity of copper oxide was taken representing from eight to twenty-four grammes of oxygen. The method, as will at once be seen, is in all essential features similar to that usually employed for determining the composition of water. The figures in the third column, deduced from the weights given by Stas, represent the quantity of carbon monoxide corresponding to one gramme of oxygen: 9.265 grm. 0 25-483 C02. 1.75046 8.327 " 22.900 " I1.75010 I3.9438 " 38-351 I1.75040 II.6124 " 31.935 " 1.75008 I8.763 " 51.6055 " 1.75039 I9.581 53.8465 " 1.74994 22.515, 6i.926 " 1.75043 24.360 " 67.003 " 1.75053 Mean, 1.75029, --.00005 Itence the molecular weight of carbon monoxide is 27.9404, +.0062. And C - 11.9771, -.0071. Now, in order to complete our discussion, we must combine the four values we have found for carbon: I. By Liebig and Redtenbacher__C 1= 2.0363, -.0028 2. By Maumen6's figures ____ " = II.9219, 4-.0III 3. By combustion of carbon___. " = I11.9730, -.0030 4. By Stas' method 11__ _. __ " = II.977I, --.007I General mean __. ____ " 1 I2.0021, -4-.0019 But values one and two are hardly reliable enough to be included in our final estimate. They involve dangerous constant errors, and ought, therefore, to be disregarded. Rejecting them altogether, and taking a general mean from values three and four, we get for the most probable figure for the atomic weight of carbon, C - 11.9736, _+.0028. If oxygen is 16, then carbon becomes 12.0011. In other words, the ratio between oxygen and carbon is almost exactly 16 to 12. BARIUM. 57 BARIUM. For determining the atomic weight of barium we have a series of six ratios, established by the labors of Berzelius, Turner, Struve, Pelouze, Marignac, and Dumas. Andrews* and Salvetat,t in their papers upon this subject, gave no details nor weighings; and, therefore, their work may be properly disregarded. First in order in point of importance, if not first chronologically, is the ratio between silver and anhy.drous barium chloride, as determined by Pelouze, Marignac, and Dumas. Pelouze,. in 1845, made the three subjoined estimations of this ratio, using his well known volumetric method. A quantity of pure silver was dissolved in nitric acid, and the amount of barium chloride needed to precipitate it was accurately ascertained. In the last column I give the quantity of barium chloride proportional to 100 parts of silver: 3.860 grm. BaC!2 ppt. 4.002 grm. Ag. 96-452 5.790 " 6.003 " 96.452 2.895 3.001 " 96.468 Mean, 96.4573, -4-.0036 Essentially the same method was adopted by Marignacll in 1848. His experiments were made upon four samples of barium chloride, as follows. A, commercial barium chloride, purified by recrystallization from water. B, the same salt, calcined, redissolved in water, the solution saturated with carbonic acid, filtered, and allowed to crystallize. C, the preceding salt, washed with alcohol, and again recrystallized. D, the same, again washed with alcohol. For 100 parts of silver the following quantities of chloride were required: * Chemical Gazette, October, I852. t Compt. Rend., I7, 318. $ Compt. Rend., 20, 1047. Journ. fiir Prakt. Chem., 35, 73. I! Arch. d. Sci. Phys. et Nat., 8, 271. 58 THE ATOMIC WEIGHTS. A. 96.356 96.345 96.362 Mean, 96.3543, -- 0033 B. 96.356 96.452 Mean, 96.354, 4-.OOI3 C. 96.358 96.363 Mean, 96.3605, --.0017 D. 96-346 96.384 96.36i 96.377 iMean, 96.367, -.0057 Dumas* employed barium chloride prepared from pure barium nitrate, and took the extra precaution of fusing the salt at a red heat in a current of dry hydrochloric acid gas. Three series of experiments upon three samples of chloride gave the following results: Series A. 1.7585 grm. BaCI2 = 1.826 grm. Ag. Ratio, 96.303 3.842 " 3.988 " 96-339 2.1585 2.2405 96-340 4.0162 " 4. I68 " 96.358 Mean, 96.3325, —.0068 *Ann. Chem. Pharm., 113, 22. I86o. Ann. Chim. Phys., (3,) 55, I29. BARIUM. 59 Series B. 1.6625 grm. BaC12 1.727 grm. Ag. Ratio, 96.265 2.4987 " 2-5946 " 96.304 3.4468 " 3.579 " 96.306 4.0822 " 4.2395 " 96.290 4.2062 " 4.3683 " 96.289 4.4564 " 4.629 " 96.271 8.6975 " 9.o03 " 96.307 Mean, 96.2902, +__.0043 Series C. 2.2957 grm. BaCI2 = 2.3835 grm. Ag. Ratio, 96.316 4.1372 i" 4.293 " 96.37I 4.2662 " 4.430 " 96.303 4.4764 " 4.647 " 96.329 5.6397 i" 5.852 " 96.372 Mean, 96.3382, ~.00o96 We have now eight series of experiments upon this ratio, representing thirty distinct estimations. Combining, we get a general mean as follows: Pelouze__ - 96.4573, --.0036 Marignac, A 96.3543, -.0033 " B 96.3540, -.0013 ( C -__ ____-_____ 96.3605, -.OO17 d D -__ ------- 96.3670, -.0057 Dumas, A - 96.3325,.o0068 (" B-____ _ _____96.2902, -.0043 C —---- --------- --- 96.3382, -.oo96 General mean-_ ___ _ 96.3596, -.oo009 The ratio between silver and crystallized barium chloride has also been fixed by Marignac.* The usual method was employed, and two series of experiments were made; in the second of which the water of crystallization was determined previous to the estimation. Five grammes of chloride were taken in each determination. The following quantities of BaC2.2H,20 correspond to 100 parts of silver: *Journ. f. Prakt. Chem., 74, 212. i858. 60 THE ATOMIC WEIGHTS. A. B. II3.IO9 113.135 113.135 113.122 113.097 I 13.060 Mean, I I3. 114, -4-.0074 Mean, 113. I06, -.oI54 The general mean from both series is 113.113, 4-.0067. The direct ratio between the chlorides of silver and barium was early established both by Berzelius* and Turner.t Berzelius found that 100 parts of dry barium chloride gave of silver chloride: i38.o6 138.08 Mean, I38.o07, 4-.007 Turner made five experiments, with the following results: 137-45 137.54 137.70 I37.62 137.64 Of these, Turner regards the fourth and fifth as the most exact. These give a mean of 137.63, _+.007, while the other three are in mean 137.563, +.049. Combining Berzelius' figures with those of Turner, we get as follows: Berzelius-1_ I__________ 138.07, -.007 Turner, I, 2, 3 I37-.563,. 049 " 4, 5- I37.63, -.007 General mean_ 1___-___ I37.841, -.0047 Incidentally to some of his other work Marignacl determined the percentage of water in crystallized barium chloride. Two sets of three experiments each were made, the first upon five grammes and the second upon ten grammes of salt. The following are the percentages obtained:: Poggend. Annal., 8, I77. t Phil. Trans., I829, 291. $ Journ. f. Prakt. Chem., 74, 212. 1858. BARIUM. 61 A. B. I4.790 14.80 14-796 I4.8I 14.800 14.80 Mean, I4.795, -.oo0019 Mean, 14.803, ~.002 General mean of both series, 14.799, ~.oo14 The ratio between barium nitrate and barium sulphate has been determined only by Turner.* According to his experiments 100 parts of sulphate correspond to the following quantities of nitrate: I 112.o60 111.990 I 2.035 Mean, II2.028, -.OI4 For the similar ratio between the sulphate and the chloride there are experiments by Turner, Berzelius, Struve, and Marignac. Turnert found that 100 parts of chloride ignited with sulphuric acid gave 112.19 parts of sulphate. By the common method of precipitation and filtration a lower figure was obtained, because of the slight solubility of the sulphate. This point bears directly upon many other atomic weight determinations. Berzelius,j treating barium chloride with sulphuric acid, obtained the following results in BaSO4 for 100 parts of BaCil: 112.17 112.i8 Mean, 112.175, 4-.0034 Struve,ll in two experiments, found: I 12.0912 I 112.0964 Mean, 112.0938, -.00I8 * Phil. Trans., 1833, 538. t Phil. Trans., I829, 291. $ Poggend. Annal., 8, 177. II Ann. Chem. Pharm., 80, 204. I85I. 62 THE ATOMIC WEIGHTS. Marignac's* three results are as follows: 8.520 grm. BaCI2 gave 9.543 BaSO4. Ratio, II2.007 8.519 " 9.544 " 112.032 8.520 " 9.542 " 111.995 Mean, II2.011, 4-.0071 Rejecting Turner's single result as unimportant, we may combine the other series: Berzelius.____. _____- 112.175, 4-.0034 Struve _____-___.._____, __.. 112.0938, 4-.OO18 Marignac _ _ I12.011 I, ~.0071 General mean.-.____ __ 112.io6, 4-.0015 The data from which we are to calculate the atomic weight of barium may now be tabulated as follows: (I.) Ag2: BaCl2:: Ioo: 96-3596, 4-.0009 (2.) Ag2: BaC12.2H20:: 100: 113. 113, 4-.0067 (3.) BaC12: 2AgCl:: 103: 137-841, 4-.0047 (4.) Per cent. of H20 in BaC12.2H20, I4.799, 4.0014 (5.) BaSO4: BaN20:: 112.028, -.014 (6.) BaCI,: BaSO4:: Ioo: 112. 106, ~.OI5 From these ratios, with the aid of the atomic weights already established, we can immediately calculate four independent values for the molecular weight of BaCl2: From (I) -B__ BaCl2 = 207.510, 4-.OI9 From (2) _-____-____ " 207.662, -.027 From (3) ____ 207.536, ~-.017 From (4) ___ ____" -206.837, 4-.045 General mean. " = 207.505, -.011 We have here an interesting example of the compensation of constant errors. Ratios (2) and (4) both represent work done by Marignac upon barium chloride containing water of crystallization. If now, as is not improbable, the salt contained a trifling excess of water, the molecular weight of barium chloride as calculated from (2) would come out too high, while on the other hand the result from ratio (4) would err in the opposite direction. In point of fact, the Journ. f. Prakt. Chem., 74, 212. 1858. BARIUM. 63 two results in the present calculation nearly compensate each other, and, on account of their relatively high probable errors, they exert but an unimportant influence upon the general mean. In conclusion, we have three independent values for the atomic weight of barium: From mol. wt. of BaCl2 ___Ba = I36.765, +-.03I From ratio (5) _ ___ — = 136.795, - ~364 From ratio (6),, --- "= 36.595, 4-.309 General mean - __," 1 I36.763, -.o031 If O = 16, then Ba =- 137.007. In other words, the ratio between oxygen and barium is almost an exact ratio between two whole numbers. In the above discussion it will at once be noticed that the second and third values for Ba have very high probable errors, and that they therefore exert almost no influence upon the general mean. This fact by no means renders them worthless however, for, at the lowest estimate, they are useful in confirmation of the better determinations. It is also highly probable that the method of discussion, rigidly carried out, does not do them absolute justice. 64 THE ATOMIC WEIGHTS. STRONTIUNIM. The ratios which fix the atomic weight of strontium resemble in general terms those relating to barium, only they are fewer in number and represent a comparatively small amount of work. The early experiments of Stromeyer,* who measured the volume of CO2 evolved from a known weight of strontium carbonate, are hardly available for the present discussion. So also we may exclude the determination by Salvetat,t who neglected to publish sufficient-details. Taking the ratio between strontium chloride and silver first in order, we have series of figures by Pelouze and by Dumas. Pelouzet employed the volumetric method already described under barium, and in two experiments obtained the subjoined results. In another column I append the ratio between SrCl2 and 100 parts of silver: 1.480 grm. SrC12 - 2.014 grm. Ag. 73.486 2.2I0 " 3.008 " 73-471 Mean, 73.478t, - -.0050 Dumas,ll by the same general method, made sets of experiments with three samples of chloride which had previously been fused in a current of dry hydrochloric acid. His results, expressed in the usual way, are as follows: Series A. 3.I37 grm. SrCI2 -= 4.280 grm. Ag. Ratio, 73.2944 I.982,, 2.705," 73.2717 3.o04I " 4. I42 " 73.4I86 3.099 " 4.219 " 73-4534 Mean, 73.3595, 4-.0303 * Schweigg. Journ., 19, 228. I8I6. t Compt. Rend., 17, 318. 1843. t Compt. Rend., 20, 1047. I845. [[ Ann. Chim. Phys., (3,) 55, 29. I859. Ann. Chem. Pharm., II3, 34. STRONTIUM. 65 Series B. 3.356 grin. SrCJ2,- 4.574 grin. Ag. Ratio, 73-3713 6.3645 " 8.667 " 73-4327 7.131 9.712 " 73-4246 Mean, 73.4095, -.OI130 Series C. 7.2I3 grm. SrC12 = 9.8II grm. Ag. Ratio, 73.5195 2.206 " 3.006 " 73-3866 4.268 " 5.816 " 73-5529 4.018 5.477 73.3613 Mean, 73-4551, 4-.0321 Combining, we have: Pelouze ---------------------- 73.478I, -.0050 Dumas, A_______ —------- -------- 73.3595, ~- -0303 " B. _________ —----- 73-4095, -.0130 " C -___ _____ — _ ----- 73-455I, 4.0321 General mean_ ____- _ 73.4655, +.C046 The foregoing figures apply to anhydrous strontium chloride. The ratio between silver and the crystallized salt, SrC12.6HI 20, has also been determined in two series of experiments by Marignac.* Five grammes of salt were used in each estimation, and, in the second series, the percentage of water was first determined. The quantities of the salt corresponding to 100 parts of silver are given in the last column: Series A. 5 grm. SrCI2.6H20 = 4.0515 grm. Ag. 123.4II 4.0495 I23.472 4.0505 1" 23.442 Mean, 123.442, 4-.012 Series B. 5 grm. SrC12.6H20 -- 4.0490 grm. Ag. I23.487 4.0500,, 123.457..4.0490 " I23-487 Mean, 123.477, -.007 General mean of both series, 123.470, -.006 * Journ. Prakt. Chem., 74, 216. 1858. 5 66 THE ATOMIC WEIG1ITS. In the same paper Marignac gives two sets of determinations of the percentage of water in crystallized strontium chloride. The first set, corresponding to " B " above, comes out thus: 40.556 40.568 40.566 Mean, 40.563, ~.0024 In the second set ten grammes of salt were taken at a time, and the following percentages were found: 40.58 40.59 40.58 Mean, 40o. 583, -.0020 General mean, from both series, 40.575, +-.00I5 The chloride used in the series of estimations last given was subsequently employed for ascertaining the ratio between it and the sulphate. Converted directly into sulphate, 100 parts of chloride yield the quantities given in the third column: 5.942 grm. SrCl2 gave 6.887 grm. SrSO4. 115.932 5.94I " 6.8855 " I 5.949 5.942 t 6.884 " I 5.927 Mean, 115.936, +.004 Now, to sum up the ratios and calculate the atomic weight of strontium. (I.) Ag: SrC12:: 100: 73.4655, -.0046 (2.) Ag: SrC12.6HO:: IOO: I23.470, -.oo6 (3.) Per cent. of H20 in SrCl2.6H20, 40.575, -.0015 (4-) SrC12: SrSO4:: IOO: II5.936, 0.o04 We now have the molecular weight of SrC1,, as follows: From (I) __SrC1 = 58.208, 4-.017 From (2) __ —--------- "= 158.-13, -.034 From (3) —---- = I57.852, -.032 General mean ___ " 158.I124, --.014 CALCIUM. ()7 And for the atomic weight of strontium itself we have two values, as follows: I. From mol. wt. of SrC12 Sr = 87.384, -4-.032 2. From (4)__ ________ " 86.765, ~-.244 General mean_ _.__ " — = 87.374, 4-.032 If 0 - 16, then Sr - 87.575. CALC I T I. For determining the atomic weight of calcium we have sets of experiments by Berzelius, Erdmann and Marchand, and Dumas. Salvetat* also has published an estimation, but without the details necessary to enable us to make use of his results. I also find a referencet to some work of Marignac; which, however, seems to have been of but little importance. The earlier work of Berzelius was very inexact as regards calciumn, and it is not until we come down to the year 1842 that we find any material of decided value. The most important factor in our present discussion is the composition of calcium carbonate, as worked out by Dumas and by Erdmann and Marchand. In 1842 Dumas4 made three ignitions of Iceland spar, and determined the percentages of carbon dioxide driven off and of lime remaining. The impurities of the material were also determined, the correction for them applied, and the weighings reduced to a vacuum standard. The percentage of lime came out as follows: 56.12 56.04 56.06 Mean, 56.073, 4-.oi6 * Compt. Rend., I7, 318. I843. t See Oudeman's monograph, p. 51. I Compt. Rend., 14, 537. I842. 68 THE ATOMIC WEIGHTS. About this same time Erdmann and Marchand* began their researches upon the same subject. Two ignitions of spar, containing.04 per cent. of impurity, gave respectively 56.09 and 56.18 per cent. of residue; but these results are not exact enough for us to consider further. Four other results obtained with artificial calcium carbonate are more noteworthy. The carbonate was precipitated from a solution of pure calcium chloride by ammonium carbonate, was washed thoroughly with hot water, and dried at a temperature of 1800. With this preparation the following residues of lime were obtained: 56.03 55.98 56.oo 55-99 Mean, 56.o00, -.007 It was subsequently shown by Berzelius that calcium carbonate prepared by this method retains traces of water even at 200~, and that minute quantities of chloride are also held by it. These sources of error are, however, in opposite directions, since one would tend to diminish and the other to increase the weight of residue. In the same paper there are also two direct estimations of carbonic acid in pure Iceland spar, which correspond to the following percentages of lime: 56.00 56.02 Mean, 56.01, -.007 In a still later papert the same investigators give another series of results based upon the ignition of Iceland spar. The impurities were carefully estimated, and the percentages of lime are suitably corrected: * Journ. fiir Prakt. Chem., 26, 472. I842. t Journ. ffir Prakt. Chem., 31, 269. I844. CALCIUMS. 69 4.2134 grm. CaCO3 gave 2.3594 grin. CaO. 55-997 per cent. 15.1385 " 8.48io " 56.022 23.5503 t 13. i958 " 56.03I,, 23.6390 " 13.2456 " 56.032 42.0295,, 23.5533 4" 56.044 " 49.7007,, 27.8536," 56.042 it Mean, 56.028, -.0047 Six years later Erdmann and Marchand* published one more result upon the ignition of calcium carbonate. They found that the compound began giving off carbon dioxide below the temperature at which their previous samples had been dried, or about 200~, and that, on the other hand, traces of the dioxide were retained by the lime after ignition. These two errors do not compensate each other, since both tend to raise the percentage of lime. In the one experiment now under consideration these errors were accurately estimated, and the needful corrections were applied to the final result. The percentage of residual lime in this case came out 55.998. This agrees tolerably well with the figures found in the direct estimation of carbonic acid, and, if combined with those two, gives a mean for all three of 56.006, +.0043. Combining all these series we get the following result: Dumas 56.073, ~_.OI6 Erdmann and Marchand.__._.. 56.oo6, ~-.oo7.-... 56.028,.0047. —----- 56.oo6,.00443 General mean- _ 56.0I98, 4.0029 For reasons given above this mean is probably vitiated by a slight constant error, which makes the figure a trifle too high. In the earliest of three papers by Erdmann and Marchand there is also given a series of determinations of the ratio between calcium carbonate and sulphate. Pure Iceland * Journ. fuir Prakt. Chem., 50o 237. I850o. 70 THE ATOMIC WEIGHTS. spar was carefully converted into calcium sulphate, and the gain in weight noted. One hundred parts of spar gave of sulphate: 136.07 I36.06 136.02 136.06 Mean, I36.0525, 4-.007I In 1843 the atomic weight of calcium was redetermined by Berzelius,* who investigated the ratio between lime and calcium sulphate. The calcium was first precipitated from a pure solution of nitrate by means of ammonium carbonate, and the thoroughly washed precipitate was dried and strongly ignited in order to obtain lime wholly free from extraneous matter. This lime was then, with suitable precautions, treated with sulphuric acid, and the resulting sulphate was weighed. Correction was applied for the trace of solid impurity contained in the acid, but not for the weighing in air. The figures in the last column represent the percentage of weight gained by the lime upon conversion into sulphate: 1.80425 grm. CaO gained 2.56735 grm. 142.295 2.50400,, 3.57050 " 142.592 3.90000 " 5.55140 " I42.343 3.04250 " 4.32650 " I42.202 3.45900 " 4.93140 " 142.567 Mean, I42.3998, --.0518 Last of all we have the ratio between calcium chloride and silver, as determined by Dumas.t Pure calcium chloride was first ignited in a stream of dry hydrochloric acid, and the solution of this salt was afterwards titrated with a silver solution in the usual way. The CaC1, proportional to 100 parts of Ag is given in a third column:; Journ. fiir Prakt. Chem., 31, 263. Ann. Chem. Pharm., 46, 24I. t Ann. Chim. Phys., (3,) 55, I29. I859. Ann. Chem. Pharm., I3, 3[. CALCIUM. 71 2.738 grm. CaC12 = 5.309 grin. Ag. 51.573 2.436 it 4.731 " 51.490 1.859 " 3.617 " 51.396 2.771 " 5-3885 " 51.424 2.240 i" 4-3585 " 51.394 Mean, 51.4554, -.0230 We have now four ratios to calculate from, as follows: (I.) Per cent. of CaO in CaCO3, 56.0198, 4-.0029 (2.) CaO: SO3:: 100: 142.3998, 4-.o5I8 (3-) CaCO: CaSO4:: I00: I36.0525, -~.0071 (4.) Ag: CaC2:: IOO: 51.4554, -.0230 These give us the subjoined values for calcium: From (I) _____ __________ Ca - 39.955, 4-.01 I From (2)-_ "_ 40o. 39, -.023 From (3)-, __ 39.925, -.o68 From (4) — 40.069, -.058 General mean -_. " -- 39.990, +-.oIo If 0 = 16, then Ca = 40.082. A glance at the above figures will show that, if, as is probable, the value deduced from the composition of calcium carbonate is a trifle too high, the general mean must be too high also. It is, therefore, interesting to see what result the very latest of Erdmann and Marchand's experiments will lead to. They found, after taking every precaution, in a single experiment that calcium carbonate yielded 55.998 per cent. of lime. From this we get Ca = 39.905; or, if 0 - 16, Ca = 39.997. It is possible, then, that " Prout's law" may hold good for calcium. 72 THE ATOMIC WEIGHTS. LEAD. For the atomic weight of lead we have to consider experiments made upon the oxide, chloride, nitrate, and sulphate. The researches of Berzelius upon the carbonate and various organic salts need not now be considered, nor is it worth while to take into account any work of his done before the year 1818. The results obtained by Dbbereiner* and by Longchampt are also without special present value. For the exact composition of lead oxide we have to depend upon the researches of Berzelius. His experiments were made at different times through quite a number of years; but were finally summed up in the last edition of his famous " Lehrbuch."t In general terms his method of experiment was very simple. Perfectly pure lead oxide was heated in a current of hydrogen, and the reduced metal weighed. From his weighings I have calculated the percentages of lead thus found and given them in a third column: Earlier Results. 8.045 grm. PbO gave 7.4675 grm. Pb. 92.8217 per cent. 14.183 " i3.165 " 92.8224 1o.8645 " Io.o84 " 92.8160 " I3.1465 I 12.2045 " 92.8346 2I.9425, 20.3695 " 92.8313 11.159 " Io.359 92.8309 " Latest. 6.6155 " 6. I41 " 92.8275 " 14.487 " 13-448 92.8280 14.626 " I3.5775 92.8313 Mean, 92.827I, -.0013 For the synthesis of lead sulphate we have data by Berzelius, Turner, and Stas. Berzelius,jl whose experiments X*Schweig. Journ., 17, 24I. I8I6. t Ann. Chim. Phys., 34, 105. I827. + Bd. 3, s. I218. [1 Lehrbuch, 5th Ed., 3, I I87. LEAD. 73 were intended rather to fix the atomic weight of sulphur, dissolved in each estimation ten grammes of pure lead in nitric acid, then treated the resulting nitrate with sulphuric acid, brought the sulphate thus formed to dryness, and weighed. One hundred parts of metal yield of PbSO4: 146.380 146.430 I46.440 146-458 Mean, I46.49, 4-.012 Turner,* in three similar experiments, found as follows: 146.430 I46.398 146.375 Mean, 146.401, ~.01 In these results of Turner's absolute weights are implied. The results of Stas' syntheses,t effected after the same general method, but with variations in details, are as follows. Corrections for weighing in air were applied: 146-443 146.427 146.419 I46.432 146.421 146.423 Mean, 146.4275, 4-.0024 Combining, we get the subjoined result: Berzelius-_-__ _..._._._.__ Ix46.419, 4-.012 Turner _ I46.40I, --.OI I Stas __________________ 146.4275, 4-.0024 General mean.... _____ 46.4262, 4-.0023 Turner, in the same paper, also gives a series of syntheses of lead sulphate, in which he starts from the oxide instead * Phil. Trans., 1833, 527-538.! Aronstein's Translation, 333. 74 THE ATOMIC WEIGHTS. of from the metal. One hundred parts of PbO, upon conversion into PbSO4, gained weight as follows: 35.84 35.7I 35.84 35.75 35.79 35.78 35.92 Mean, 35.804, ~-.oI8 These figures are not wholly reliable. Numbers one, two, and three represent lead oxide contaminated with traces of nitrate. The oxide of four, five, and six contained traces of miniulll; Number seven was free from these sources of error, and, therefore, deserves more consideration. The series as a whole undoubtedly gives too low a figure; and this error would tend to slightly raise the atomic weight of lead. Still a third series by Turner establishes the ratio between the nitrate and the sulphate; a known weight of the former being in each experiment converted into the latter. One hundred parts of sulphate represent of nitrate: I09.312 I09.3IO 109.300 Mean, IO9.307, 4-.002 In all these experiments by Turner the necessary corrections were made for weighing in air. For the ratio between lead chloride and silver we have a series of results by Marignac and one experiment by Dumas. There are also unavailable data by Turner and by Berzelius. Marignac,* applying the method used in his researches upon barium and strontium, and working with lead chloride which had been dried at 200~, obtained these results. * Journ. fiir Prakt. Chem., 74, 218. I858. LEAD. 75 The third column gives the ratio between PbCl., and 100 parts of Ag: 4.9975 grm. PbC12 - 3.88IO grm. Ag. 128.768 4.9980,, 3.8835 " 128.698 5.0000 t" 3.8835 " I28.750 5.0000,, 3.8860," 128.667 Mean, 128.721, —.oi6 Dumas,* in his investigations, found that lead chloride retains traces of water even at 250~, and is sometimes also contaminated with oxychloride. In one estimation 8.700 grammes PbC1, saturated 6.750 of Ag. The chloride contained.009 of impurity; hence, correcting, Ag: PbCl,:: 100: 128.750. If we assign this figure equal weight with those of Marignac, we get as the mean of all, 128.7266, 4-.013. The sources of error indicated by Dumas, if they are really involved in this mean, would tend slightly to raise the atomic weight of lead. The synthesis of lead nitrate, as carried out by Stas,t gives excellent results. Two series of experiments were made, with from 103 to 250 grammes of lead in each determination. The metal was dissolved in nitric acid, the solution evaporated to dryness with extreme care, and the nitrate weighed. All weighings were reduced to the vacuum standard. In series A the lead nitrate was dried in an air current at a temperature of about 155~. In series B the drying was effected in vacuo. 100 of lead yield of nitrate: A. I59.973 I59.975 159.982 I59.975 159.968 159.973 Mean, I59.9743, --.0012 * Ann. Chem. Pharm., II3, 35. I86o. t Aronstein's Translation, 326. 76 THE ATOAMIC WEIGHTS. B. I59.970 I59.964'59.959 I59.965 Mean, 159.9645, -.oo005 Mean from both series, I59.9704, -~.ooIo There still remain to be noticed two sets of experiments upon lead nitrate, which were originally intended to establish the atomic weight of nitrogen. Lead nitrate was carefully ignited and the residual oxide weighed. The first series, bearing Svanberg's name,* gives simply the percentage of oxide found, as follows: 67-4030 67.4036 67-4043 67.3956 Mean, 67.4016, ~-.0014 The second series is by Anderson,t and gives the weighings upon which the percentages rest. The latter come out thus: 5.I9485 grm. PbN206 gave 3.50I7 grm. PbO. 67.407I per cent. 9.7244 " g 6.5546 " 67-4037 9.2i8I " 6.2I 34 " 67-4044 9.6530 id 6.5057 " 67-3957 Mean, 67.4027, -.ooi6 It will at once be seen that these series are identical; the discordance between the first figures of the two being undoubtedly due to some misprint in the weighings of the Anderson set. How it happens that the same work has been published by two separate authors I will not attempt to explain; neither will I undertake to determine which of the two is really entitled to credit. *Journ. fiir Prakt. Chem., 27, 381. 1842. t Ann. Chim. Phys., (3,) 9, 254. 1843. LEAD. 77 We have now seven ratios upon which to base our computations: (I.) Per cent. of Pb in PbO, 92.8271, ~-.0013 (2.) Per cent. of PbO in PbN206, 67.40oi6, -0.0014 (3-) Pb: PbSO4:: Ioo: I46.4262, ~.0023 (4.) PbO: PbSO4:: o10: I35.804, --.oi8 (5.) PbSO4: PbN206:: leo: Io9.307, -~_.oo2 (6.) Pb: PbN206:: 10oo: 159.9704, ~-.ooIo (7.) Ag: PbC2:: 100: 128.7266, 4-.013 Discussing these separately, we get an equal number of values for the atomic weight of lead: From (I) _ ________Pb = 206.587, 4-.059 " (2)_______________ " = 207.046, --.041 (3) - " 206.435, -4-.041 (4)__-___________ " —- _ 207.I3I, --.ii8 " (5) —--- ---— _-_____ " = 204.803, --.329 " (6) _______ _____ - -- 206.454, 4-.037 " (7) ----------------- 206.473, 4-.o42 General mean _-____ = 206.604, --.019 If 0 = 16, this becomes Pb = 207.079. In the above discussion are included several values which diverge widely from this general mean, and which, for other reasons, are probably erroneous. Although but one of these carries much weight, it is as well to exclude them, and to base our computations upon the others. If, now, we reject the second, fourth, and fifth values, we get for the atomic weight of lead, Pb = 206.471, +.021. If O = 16, this becomes Pb - 206.946. From the synthesis of the nitrate Stas found 206.918, and from the sulphate, 206.934. The agreement of these values with our own general mean is certainly very close. 78 THE ATOMIC WEIGHTS. FLUORINE. The atomic weight of fluorine has been determined only by one general method, namely, by the conversion of fluorides into sulphates. Excluding the early results of Davy,* we have only to consider the experiments of Berzelius, Louyet, Dumas, and DeLuca, with reference to the fluorides of calcium, sodium, potassium, barium, and lead. The ratio between calcium fluoride and sulphate has been determined by the four investigators above named, and by one general process. The fluoride is treated with strong sulphuric acid, the resulting sulphate is ignited, and the product weighed. In order to ensure complete transformation special precautions are necessary; such, for instance, as repeated treatment with sulphuric acid, and so on. For details like these the original papers must be consulted. The first experiments in chronological order are those of Berzelius,t who operated upon an artificial calcium fluoride. He found, in three experiments, for one part of fluoride the following of sulphate: 1.749 1.750 1.751 Mean, 1.750, -4-.0004 Louyet's researches' were much more elaborate than the foregoing. He began with a remarkably concordant series of results upon fluor spar, in which one gramme of the fluoride yielded from 1.734 to 1.737 of sulphate. At first he regarded these as accurate, but he soon found that particles of spar had been coated with sulphate, and had therefore escaped action. In the following series this source of error was guarded against. * Phil. Trans., I814, 64. t Poggend. Annal., 8, I. I826. + Ann. Chim. Phys., (3,) 25, 300. I849. FLUORINE. 79 Starting with fluor spar, Louyet found of sulphate as follows: 1.742 1.744 1.745 1.744 I.7435 I.7435 Mean, 1.7437, ~.0003 A second series, upon artificial fluoride, gave: I.743 I.74.T 74 Mean, I.7417, -~.0004 Dumas* published but one result for calcium fluoride..495 grm. gave.864 grm. sulphate, the ratio being 1: 1.7455. De Lucat worked with a very pure fluor spar, and published the following results. The ratio between CaSO4 and one gramme of CaF, is given in the third column:.9305 grmn. CaF2 gave I.630 grin. CaSO4. 1.75I8.836 " 1.459 " 1.7452.502 ".8755 " 1.7440.3985 ".6945 " 1.7428 If we include Dumas' single result with these, we get a mean of 1.7459, +.0011. - Upon combining all these series, we get as follows: Berzelius ____ ____ _ _ — 1.7500, 4.0004 Louyet, Ist series -_.___ _____. I.7437, -.0003 2d ".___ I7417, ~.0004 De Luca and Dumas_-__ 1____ I.7459, ~.ooII General mean__ -___ 1.74493, 4-.0002 For the ratio between the two sodium salts we have experiments by Dumas. and by Louyet.1 According to Louyet one gramme of NaF gives of Na,S,0: * Ann. Chem. Pharm., I I3, 28. I86o. t Compt. Rend., 5I, 299. i86o. f See the papers already quoted. 80 THE ATOMIC WEIGHTS. i.686 I.683 I.685 Mean, 1.6847, 4-.ooo6 The weighings published by Dumas are as follows:.777 grm. NaF give 1.312 grm. Na2S04. Ratio, 1.689 1.737 " 2.930 ". 1.687 Mean, 1.688, 4-.0007 The general mean of both series is 1.6863, ~.0004. Dumas also gives experiments upon potassium fluoride. The quantity of sulphate formed from one gramme of fluoride is given in the last column: 4.483 grm. KF give 2.225 grm. K2SO4. 1.5002 1.309 " 1.96I " 1.498I Mean, 1.4991, 4-.0007 The ratios for the fluorides of lead and of barium are due entirely to Louyet. One gramme BaF2 gave of BaSO4: 1.332 1.331 1.330 Mean, 1.331, -.0004 With the lead fluoride a new method of treatment was adopted. The salt was fused, powdered, dissolved in nitric acid, and precipitated by dilute sulphuric acid. The evaporation of the fluid and the ignition of the sulphate was then effected without transfer. Five grammes of fluoride were taken in each operation, yielding of sulphate: 6. I79 6.178 6.178 Mean, 6. I783, 4-.0002 We now have five ratios to calculate from, as follows: FLUORINE. 81 (I.) CaF2: CaS0e4:: I.o: 1.74493, 4.0002 (2.) NaF: NaSO4:: I.O: 1.6863, -.0004 (3.) KF: K2SO4:: I.o0:.499I, 4-.0007 (4.) BaF2: BaSO4:: 1.o: 1;3310, ~.0004 (5.) PbF: PbSO4:: 5.0: 6.1783, -.0002 From these we get five values for F: From (I)_-________-____-F - 18.926, -.009 " (2)_________________ _ " = 19.050, --.014 (3) —---------------- 8.975,.032 " (4)_ " —_ -_ - I8.993, -.033 " (5) —---- _1____ ____- I9.092, +-.o16 General mean 18.984, o-.0065 If 0 = 16, this becomes 19.027. Before leaving the subject of fluorine we must notice two possible sources of error beyond the always to be considered one of impurities in the materials employed. First, an incomplete conversion of a fluoride into a sulphate would lead to results tending to raise the atomic weight of fluorine. On the other hand, the value for fluorine which has most weight is that derived from calcium fluoride. But it was shown under calcium that the atomic weight determined for that metal was probably a trifle too high. This error, introduced into our fluorine calculations, tends to lower our final results. These two errors, then, if they really exist, will, in part at least, compensate each other. 82 THE ATOMIC WEIGHTS. PHOSPHORUS. The material from which we are to calculate the atomic weight of phosphorus is by no means abundant. Berzelius, in his Lehrbuch,* adduces only his own experiments upon the precipitation of gold by phosphorus, and ignores hll the earlier work relating to the composition of the phosphates. These experiments we will consider with reference to gold. Pelouze,t in a single titration of phosphorus trichloride with a standard solution of silver, obtained a wholly erroneous result; and Jacquelain,4 in his similar experiments, did even worse. Schr6tter's criticism upon Jacquelain sufficiently disposes of the latter.ll There are, in short, but two investigations upon the atomic weight of phosphorus which have any value for present purposes, namely, the researches of Schr6tter and of Dumas. These chemists worked with different materials and by different methods, and yet obtained beautifully concordant results. Schrbtter~ burned pure amorphous phosphorus in dry oxygen, and weighed the pentoxide thus formed. One gramme of P yielded P,,0 in the following proportions: 2.28909 2.28783 2.29300 2.28831 2.29040 2.28788 2.28848 2.28856 2.28959 2.28872 Mean, 2.289186, --.00033 Hence P = 30.9562, ~.0074. *5th Ed., I I88. t Compt. Rend., 20, 1047. 1 Compt. Rend., 33, 693. 11 Journ. fiir Prakt. Chem., 57, 315. Q Journ. fiir Prakt. Chem., 53, 435. 185I. PHOSPHORUS. 83 Dumas* prepared pure phosphorus trichloride by the action of dry chlorine upon red phosphorus. The portion used in his experiments boiled between 76~ and 78~. This was titrated with a standard solution of silver in the usual manner. Dumas publishes weights, from which I calculate the figures given in the third column, representing the quantity of trichloride proportional to 100 parts of silver: I.787 grm. PC13 = 4.208 grm. Ag. 42.4667 1.466 " 3.454 " 42-4435 2.056 " 4.844 " 42.4443 2.925,, 6.890 " 42.4528 3.220 " 7.582 " 42-4690 Mean, 42.4553, 4-.0036 Hence P = 31.0314, +.0467. Now, combining these two values, we have: By Schrotter P__________- - = 30.9562, --.0074 By Dumas ____ —___ " = 31.0314, ~.0467 General mean _ __ "- - 30.9580, -.oo73 If 0 - 16, this becomes 31.0292. The fact here noticeable, that Dumas' figures give a value for P slightly higher than that deduced from those of Schrbtter, may be accounted for upon the supposition that the phosphorus trichloride contained traces of oxychloride. Such an impurity would tend to raise the apparent atomic weight of phosphorus, and its occurrence is by no means improbable. *Ann. Chem. Pharm., II 3, 29. I86o. 84 THE ATOMIC WEIGHTS. BORON. The atomic weight of this element has been determined by Berzelius and by Laurent, and calculated by Dumas from some experiments by Deville. Berzelius* based his determination upon three concordant estimations of the percentage of water in borax. Laurentt made use of two similar estimations, and all five may be properly put in one series, thus: 47.10 47. Io] 47. io Berzelius. 47. Io 47.15 Laurent. 47.20 Mean, 47 I3, 4-.013 Hence B = 10.943, +-.023. Dumas'T calculations were based on Deville's analyses of the chloride and bromide of boron, which give the ratios between AgCl and BC13, and between AgBr and BBr3. Reducing the weighings to a common standard, 100 parts of silver chloride correspond to the quantities of boron trichloride given in the third column:.6763 grm. BC13 - 2.447 grm. AgC1. 27.303.923 " 3-395 27. I87 Mean, 27.245, -.039 HI-ence B- 10.808, _+.174. With the bromide, 2.446 BBr3 gave 5.496 AgBr. If we assign this experiment equal weight with one in the chloride series, and include the probable error of Br, B10.964, __.364. The three values combine as follows: * Poggend. Annal., 8, I. i826. t Journ. fir Prakt. Chem., 47, 4I5. I849. Ann. Chem. Pharm., I I 3, 3. 860. SILICON. 85 From borax_ B - 0I.943, 4-.023 From BC13 __ _______ " - Io.88, -4-.I74 From BBr3 _, __ __-____ " —= o.964, -.364 General mean-.__ __ "I 0o.94I, 4-.023 If O = 16, B = 10.966. Further investigation of the atomic weight of boron is evidently desirable. SILICON. Although Berzelius* attempted to ascertain the atomic weight of silicon, first by converting pure Si into SiO2, and later from the analysis of BaSiF6, his results were not satisfactory. We need only consider the estimations of Pelouze, Schiel, and Dumas. Pelouze,t experimenting upon silicon tetrachloride, employed his usual method of titration with a solution containing a known weight of silver. One hundred parts of Ag gave the following equivalencies of SiCl,: 39-4325 39-4570 Mean, 39.4447, -.0083 Hence Si - 28.408. Essentially the same, method was adopted by Dumas.{ Pure SiCl4 was weighed in a sealed glass bulb, then decomposed by water, and titrated. The results for 100 Ag are given in the third column: 2.899 grm. SiC1l4= 7.3558 grm. Ag. 39.411 1.242 ic 3- 54 " 39-379 3.221 " 8. I875 " 39-340 Mean, 39.377, 4-.oI4 Hence Si = 28.117. * Lehrbuch, 5 Aufl., 3, 1200. t Compt. Rend., 20, Io047. 1845. t Ann. Chem. Pharm., I 3, 33. I86o. 86 THE ATOMIC WEIGHTS. Dumas and Pelouze's series combine as follows: Pelouze ___ - -____ __________39.4447, ~.oo83 Dumas 39-377, -.OI4 General mean-__ ___ 39.4265,.00oo7 I Hence SiCl4 = 169.810, ~.034. Schiel,* also studying the chloride of silicon, decomposed it by ammonia. After warming and long standing it was filtered, and in the filtrate the chlorine was estimated as AgCl. One hundred parts of AgCl correspond to the quantities of SiCl4 given in the last column:.6738 grm. SiC14 gave 2.277 grm. AgC1. 29.592 I.3092 " 4.418 " 29.633 Mean, 29.6I25, -.o0138 Hence SiCl4 169.437, -.080, and Si = 27.957. Combining the values for SiCl4 we have this result: Pelouze and Dumas.......SiC14 I 169.8io, -0.034 Schiel -,,- - - 1_ i69.437, -.o80 General mean___. " I69.675, 4-.o31 Hence Si = 28.195, -.066; or, if 0 = 16, Si = 28.260. It will be observed that all of these determinations rest upon the composition of SiCl4, a compound for which it would not be easy to.guarantee absolute purity. All the errors likely to occur in the determination of the atomic weight would be plus errors, so that the value deduced above is almost certainly too high. * Ann. Chem. Pharm., 120, 94. LITHIUM. 87 LITHIUM. The earlier determinations of the atomic weight of lithium by Arfvedson, Stromeyer, C. G. Gmelin, and Kralovanzky were all erroneous, because of the presence of sodium compounds in the material employed. The results of Berzelius, Hagen, and Hermann were also incorrect, and need no further notice here. The only investigations which we need to consider are those of Mallet, Diehl, Troost, and Stas. Mallet's experiments* were conducted upon lithium chloride, which had been purified as completely as possible. In two trials the chloride was precipitated by nitrate of silver, which was collected upon a filter and estimated in the ordinary way. The figures in the third column represent the LiCl proportional to 100 parts of AgCl: 7.1885 grm. LiCl gave 24.3086 grm. AgCl. 29.606 8.5947, 29.062I C" 29.574 In a third experiment the LiCl was titrated with a standard solution of silver. 3.9942 grm. LiCl balanced 10.1702 grm. Ag, equivalent to 13.511 grm. AgCl. Hence 100 AgCl 29.563 LiCl. Mean of all three experiments, 29.581, +.0087. Diehl,t whose paper begins with a good resumer of all the earlier determinations, describes experiments made with lithium carbonate. This salt, which was spectroscopically pure, was dried at 130~ before weighing. It was then placed in an apparatus from which the carbon dioxide generated by the action of pure sulphuric acid upon it could be expelled, and the loss of weight determined. From this loss the following percentages of CO2 in Li2CO3 were determined: 59.422 59-404 59-440 59.401 Mean, 59.4I7, 4-.oo6 * Silliman's Amer. Journal, November, I856. Chem. Gazette, 15, 7. t Ann. Chem. Pharm., I21, 93. 88 THE ATOMIC WEIGHTS. Diehl's investigation was quickly followed by a confirmation from Troost.* This chemist, in an earlier paper,t had sought to fix the atomic weight of lithium by an analysis of the sulphate, and had found a value not far from 6.5; thus confirming the results of Berzelius and of Hagen, who had employed the same method. But Diehl showed that the BaSO4 precipitated from Li2SO4 always retained traces of Li, which were recognizable by spectral analysis, and which accounted for the error. In the later paper Troost made use of the chloride and the carbonate of lithium, both spectroscopically pure. The carbonate was strongly ignited with pure quartz powder, thus losing carbon dioxide, which loss was easily estimated. The subjoined results were obtained:.970 grin. Li2CO3 lost.577 grm. CO2. 59.485 per cent. 1.782 I.o059 " 59-427 " Mean, 59.456, ~-.020 This combined with Diehl's mean, 59.417, -.006, gives a general mean of 59.420, ~.0057. The lithium chloride employed by Troost was heated in a stream of dry hydrochloric acid gas; of which the excess, after cooling, was expelled by a current of dry air. The salt was weighed in the same tube in which the foregoing operations had been performed, and the chlorine was then estimated as silver chloride. The usual ratio between LiCl and 100 parts of AgCl is given in the third column: I.309 grm. LiCl gave 4.420 grm. AgCl. 29.615 2.750 9.300,, 29.570 Mean, 29.5925, ~.0145 This combined with Mallet's mean, 29.581, ~.0087. gives a general mean of 59.584, ~.0075. Finally, we come to the work of Stas,1 which was exe*Zeit. Anal. Chem., I, 402. t Annales d. Chim. et d. Phys., 5I, Io8. $ Aronstein's Translation, 279-302. LITHIUM. 89 cuted with his usual wonderful accuracy. In three titrations, in which all the weights were reduced to a vacuum standard, the following quantities of LiCl balanced 100 parts of pure silver: 39.356 39.357 39.361 Mean, 39.358, 4-.ooI In a second series of experiments, intended for determining the atomic weight of nitrogen, LiCl was converted into LiNO3. The method was that employed for a similar purpose with the chlorides of sodium and of potassium. One hundred parts of LiCl gave of LiNO3: I62.588 162.600 I62.598 Mean, I62.5953, 4-.0025 We have now the following ratios from which to deduce the atomic weight of lithium: (I.) AgCl: LiCI: IOO: 29.584, -.0075 (2.) Ag: LiCL:: IOO: 39.358, ~.OoI (3.) LiCl: LiNO3:: Ioo: I62.5953, 4.0025 (4.) Per cent. of CO2 in Li2CO3, 59.420, 4.0057 Hence two values for the molecular weight of LiCl: From (I) LiC = 42.3I87, +.0039 From (2) _ - __ - 42-3787, -~-.0111 General mean._ " = 42.3720, ~-.0037 For lithium itself we get three values: From molecular weight of LiCl___Li i 7.002, --.015 From ratio (3)____ _ = 7.0287, ~-.042 From ratio (4),, __ 7.0085, ~-.oo8 General mean- _____,, __ -- 7.0073, 4-.o07 If 0 - 16, then Li = 7.0235. Stas himself gives 7.022 as his determination. Difference,.0015. 90 THE ATOMIC WEIGHTS. RUBIDIUM. The atomic weight of rubidium has been determined by Bunsen, Piccard, and Godeffroy; but only from analyses of the chloride. Bunsen,* employing ordinary gravimetric methods, estimated the ratio between AgC1 and RbCl. His rubidium chloride was purified by fractional crystallization of the chloroplatinate. He obtained the following results, to which, in a third column, I add the ratio between RbCl and 100 parts of AgCl: One grm. RbCl gave I. I873 grm. AgCI. 84.225 c' I.I873 " 84.225 1.1850 " 84-388 cc I. I 880 84.175 Mean, 84.253, -.o031 The work of Piccardt was similar to that of Bunsen. In weighing, the crucible containing the silver chloride was balanced by a precisely similar crucible, in order to avoid the correction for displacement of air. The filter was burned separately from the AgCl, as usual; but the small amount of material adhering to the ash was reckoned as metallic silver. The rubidium chloride was purified by Bunsen's method. The results, expressed according to the foregoing standard, are as follows: I.I587 grm. RbC1 = 1.372 AgC1 +.ooIg Ag. 84.300 1.4055 i" 1.6632 ".0030 " 84.303 I.OOI ". I850 ".0024" 84.245 I.5I41 " 1.7934 ".oo8 " 84.313 Mean, 84.290, 4-.0105 Godeffroy,$ starting with material containing both rubidium and c~esium, separated the two metals by fractional *Zeit. Anal. Chem., i, 136. Poggend. Annal., 113, 339. i86i. tJjourn. fiir Prakt. Chem., 86, 454. i862. Zeit. Anal. Chem., I, 518. +Ann. Chem. Pharm., I8i, I85. I876. 1~~~~1111~~~~~~~'I~L~ ILLII~ V) 13 CAESIUM. 91 crystallization of their alums, and obtained salts of each spectroscopically pure. The nitric acid employed was tested for chlorine and found to be free from that impurity, and the weights used were especially verified. In two of his analyses of RbC1 the AgC1 was handled by the ordinary process of filtration. In the other two it was washed by decantation, dried, and weighed in a glass dish. The usual ratio is appended in the third column: 1.4055 grm. RbC1 gave 1.6665 grm. AgC1. 84.338 I.8096 " 2. 146I " 84.320 2.2473 " 2.665 " 84.326 2.273 " 2.6946' 84.354 Mean, 84.3345, -.005I Combining the three series, we get the following result: Bunsen 84.253, ~-.031 Rb = 85-I50 Piccard ____. 84.290, -.oIo5 " = 85.203 Godeffroy ___ — 84.3345, ~-.oo5I " =85.263 General mean___ 84.324, -.0045 Hence Rb = 85.251, +.018. If 0 = 16, Rb - 85.529. CAESIUM. The atomic weight of cmsium, like that of rubidium, has been determined from the analysis of the chloride. The earliest determination, by Bunsen,* was incorrect, because of impurity in the material employed. In 1863 Johnson and Allen published their results.t Their material was extracted from the lepidolite of IIebron, Maine, and the coesium was separated from the rubidium as bitartrate. From the pure cesium bitartrate coesium chloride was prepared, and in this the chlorine was estimated as * Zeit. Anal. Chem., I, I37. t Amer. Journ. Sci. and Arts, (2,) 35, 94. 92 THE ATOMIC WEIGHTS. silver chloride by the usual gravimetric method. Reducing their results to the convenient standard adopted in preceding chapters, we have, in a third column, the quantities of CsCl equivalent to 100 parts of AgCl: 1.8371 grm. CsC1 gave 1.5634 grm. AgC1. 117.507 2.1295 i 1.8111 " 117.580 2.70I8 " 2.2992 " 117.511 I.56165 " 1.3302 " I I7.399 Mean, 117.499, ~-.025 Shortly after the results of Johnson and Allen appeared a new series of estimations was published by Bunsen.* His c~esium chloride was purified by repeated crystallizations of the chloroplatinate, and the ordinary gravimetric process was employed. The following results represent, respectively, material thrice, four times, and five times purified: I.3835 grm. CsC1 gave.I178I grm. AgC1. Ratio, 117.435 1.3682 " I. 644 " I I7.503 1.2478.0623," 117.462 Mean, I I7.467, -.013 Godeffroy's workt was, in its details of manipulation, sufficiently described under rubidium. In three of the experiments upon caesium the silver chloride was washed by decantation, and in one it was collected upon a filter. The results are subjoined: I.5825 grm. CsC1 gave 1.35I grm. AgC1. Ratio, 117.135 1.3487 " I. I50 " 117.265 I. I880 " I.4I " I 117.48 1.2309 " 1.05 J1 I I7. I07 Mean, I 117.64, 4-.023 We may now combine the three series to form a general mean: * Poggend. Annal., I9, I. I863. t Ann. Chem. Pharm., i8i, I85. I876. THALLIUM. 93 Johnson and Allen- 11___._ II7.499, ~-.025 Cs 1 I32.706 Bunsen_________..-.____ 117.467, ~.013 "- I32.66I Godeffroy______.___ I17. 64, ~.023 " I132.227 General mean_ I 117.413, 4-.I00 Hence Cs = 132.583, --.024; or, if O = 16, Cs = 132.918. THALLIUM. The atomic weight of this interesting metal has been fixed by the researches of Lamy, Werther, Hebberling, and Crookes. Lamy and HIebberling investigated the chloride and sulphate; Werther studied the iodide; Crooke's experiments involved the synthesis of the nitrate. The last mentioned work was so thorough and admirable that the other researches are included here only for the sake of historical completeness. Lamy* gives the results of one analysis of thallium sulphate and three of thallium chloride. 3.423 grammes TI2SO4 gave 1.578 grm. BaSO4; whence 100 parts of the latter are equivalent to 216.920 of the former. In the thallium chloride the chlorine was estimated as silver chloride. The following results were obtained. In the third column I give the amount of T1Cl proportional to 100 parts of AgCl: 3.912 grm. T1CL gave 2.346 grm. AgC1. I66.752 3.-000 ".80oI5 cc I66.528 3.912 it 2.336 t 1i67.466 Mean, i66.915, 4-.I905 Hebberling'st work resembles that of Lamy. Reducing his weighings to the standards adopted above, we have from his sulphate series, as equivalent to 100 parts of BaSO4, the amounts of T1,SO4 given in the third column: * Zeit. Anal. Chem., 2, 2 11. I863. t Ann. Chem. Pharm., I34, II. I865. 94 THE ATOMIC WEIGHTS. I.4I95 grm. T12SO4 gave.6534 grm. BaSO4. 217.248 1.1924 it.5507, 216.524.8560 " -3957 " 2i6.325 Mean, 216.699 Including Lamy's single result, as of equal weight, we get a mean of 216.754. ~+.1387. From the chloride series we have these results, with the ratio stated as usual:.2984 grm. TClI gave. 791 grm. AgC1. I66.6I.5452.3278 I 66.321 Mean, I66.465, -+.097 Lamy's mean was 166.915, —.1905. Both means combined give a general mean of 166.555, _-.0865. Werther's* determinations of iodine in thallium iodide were made by two methods. In the first series TlI was decomposed by zinc and potassium hydroxide, and in the filtrate the iodine was estimated as AgI. One hundred parts of AgI correspond to the amounts of TlI given in the last column:.720 grm. T1I gave.51 grm. AgI. I41.176 2.072 " 1.472 " I40.76I.960 " t.679 " I41.384.385 ".273 " I41.026 i.o68 ".759 " I40.7II Mean, 141.OI2, -.o85 In the second series the thallium iodide was decomposed by ammonia in presence of silver nitrate, and the resulting AgI was weighed. Expressed according to the foregoing standard the results are as follows: 1.375 grm. TII gave.978 grm. AgI. Ratio, I40.593 I.540 1 1.095 140. 639 I.380 ".98I " I40.673 Mean, 140.635, -.oi6 General mean of both series, 140.648, _+.016. *Journ. fiir Prakt. Chem., 92, 128. I864. THALLIUM. 95 From the foregoing results three values for the atomic weight of thallium are calculable: From the sulphate -_-____-T1 - 204. I69, _.I66 From the chloride -____ = 203.879, 4-.126 From the iodide _..___.___ " _ 203.886, _.054 In 1873 Crookes,* the discoverer of thallium, published his final determination of its atomic weight. His method was to effect the synthesis of thallium nitrate from weighed quantities from absolutely pure thallium. No precaution necessary to ensure purity of materials was neglected; the balances were constructed especially for the research; the weights were accurately tested and all their errors ascertained; weighings were made partly in air and partly in vacuo, but all were reduced to absolute standards; and unusually large quantities of thallium were employed in each experiment. In short, no effort was spared to attain as nearly as possible absolute precision of results. The details of the investigation are too voluminous, however, to be cited here; the reader who wishes to become familiar with them must consult the original memoir. Suffice it to say that the research is a model which other chemists will do well to Copy. The results of ten experiments by Professor Crookes may be stated as follows. In a final column we may state the quantity of nitrate producible from 100 parts of thallium. The weights given are in grains: Thallium. T71NO3 + Glass. Glass Vessel. Ratio. 497-972995 112I.851852 472-557319 I30.3875 293. 93507 I I I.3870I4 729.082713 130.3930 288.562777 971.214142 594-949719 130.3926 324-963740 I 142.569408 718.849078 130-3900 183.790232 1005.779897 766.133831 I30-3912 190.842532 997 334615 748.491271 130.3920 195.544324 1022.I76679 767.203451 130.39 5 201.8I6345 I013.480135 750.332401 130-3897 295.683523 153.947672 768.403621 I30.3908 299.203036 1159.870052 769-734201 130.3917 Mean, 130.3910, 4-.00034 * Philosophical Transactions, I873, p. 277. 96 THE ATOMIC WEIGHTS. Hence, using the atomic weights and probable errors previously found for N and O, Ti = 203.715, ~.0365. If O = 16, T1- 204.183. Crookes himself, using 61.889 as the molecular weight of the group NO3, gets the value T1 = 203.642; the lowest value in the series being 203.628, and the highest 203.666; an extreme variation of 0.038. This is extraordinary accuracy for so high an atomic weight, at least as far as Crookes' work is concerned. But its value depends in reality upon the accuracy of other chemists in fixing the atomic weights of N and 0; a slight variation in either of the latter constants producing a large variation here. What Crookes really has done has been to fix with almost absolute certainty the ratio between Ti and NO3. If the latter group should have the molecular weight 62, in accordance with Prout's hypothesis, then Ti - 204.008. In other words, the ratio thus fixed by Crookes is almost exactly represented by two whole numbers, and supports Prout's hypothesis in a very decided way. Crookes himself seems to have overlooked this fact, for he regards his results as militating against the hypothesis in question. GLUCINUM. The atomic weight of glucinumr is at present much in doubt; our knowledge of it depending upon the unsettled question whether the oxide is G10O or G12 03. The formula GlO agrees with Mendelejeff's law, and is advocated by Reynolds,* Lothar Meyer,t and Brauner.$ The symbol G1203, on the other hand, is favored by Nilson and Pettersson,ll and by Humpidge.~ Humpidge, Meyer, and Brauner * Phil. Mag., (5,) 3, 38. I877. Chem. News, 42, 273. I880. t Ber. der Deutsch. Chem. Gesell., I3, 1780. I88o. Also, Ii, 576. I879. T Phil. Mag., (5,) I I. Jan., I88I. | Berichte, I, 38 and o906. I879. Also, I3, 2035. I880. @ Chem. News, 42, 26I. I880. GLUCINUM. 97 offer only theoretical discussions of the subject; Reynolds and Nilson and Pettersson have determined the specific heat of the metal, but give opposed results. In the following calculations the simpler formula will be assumed, not as a finality, but because of its accordance with the system of Mendelejeff. The data from which we are to calculate the atomic weight of glucinum have been determined by Awdejew, Weeren, Klatzo, Debray, and Nilson and Pettersson. Berzelius'* single experiment on the sulphate may be left out of account. Awdejew,?t whose determination was the earliest of any value, analyzed the sulphate. The sulphuric acid was thrown down as barium sulphate; and in the filtrate, from which the excess of barium had been first removed, the glucina was precipitated by ammonia. The figures which Awdejew publishes represent the ratio between SO, and GlO, but not absolute weights. As, however, his calculations were made with SO3 = 501.165, and Ba probably 855.29, we may add a third column showing how niuch BaSO4 is proportional to 100 parts of G1O: SO,. GIO. Ratio. 4457 1406 921.242 4531 1420 927.304 7816 2480 915.903 12880 4065 920.814 Mean, 921.316, -4- I-577 The same method was followed by Weeren and by Klatzo, except that Weeren used ammonium sulphide instead of ammonia for the precipitation of the glucina. Weerenj gives the following weights of GlO and BaSO4. The ratio is given in a third column, just as with the figures by Awdejew: * Poggend. Annal., 8, I. t " 56, io6. 1842. t " c 92, 124. 1854.'7 98 THE ATOMIC WEIGHTS. G1O. BaSO4. atlio..3I63 grm. 2.9332 gril. 927.031.2872 " 2.6377 " 9I8.419.2954 " 2.7342 " 925.592.5284 " 4.8823 " 902.946 Mean, 918.497, - 3.624 Klatzo's* figures are as follows, with the third column added by the writer: GZO. BaSO,. RaVio..2339 grin. 2. I 5 20 grm. 920.052.19I0, I-7556 gi99. 62.2673" 2.4872" 930.490.3585 " 3.3II5 " 923.710.2800 2.5842 " 922.989 Mean, 923.28I, -- 1.346 Combining these series into a general mean, we get the subjoined result: Awdejew- ____921.316, ~- I.577 Weeren__ --- 918.497, - 3.624 Klatzo __- ____-_-_ —----- 923.281, ~- 1.346 General mean-_..... —-. 922. I64, o.985 Hence G10 - 25.224, --.269. Debrayt analyzed a double oxalate of glucinuin and ammoniulm, Gl(NH 4) 2 C4 0s. In this the glucina was estimated by calcination, after first converting the salt into nitrate. The following percentages were found: 11.5 I11.2 II.6 Mean, II.433, --.o8I The carbon was estimated by an organic combustion. I give the weights, and put in a third column the percentages of CO 2 thus obtained: * Zeitschrift fuir Anal. Chem., 8, 523. I869. - Ann. de Chim. et de Phys., (3,) 44, 37. i855. GLUCINUlI. 99 Salt. CO2. Per cent. COW..600 grm..477 grm. 79.500.603".478 " 79.270.600 ".477 " 79.500 Mean, 79.423, ~-.052 Calculating the ratio between CO2 and GlO, we have for the molecular weight of the latter, GlO - 25.220, ~.180. The agreement between this result and the one previously deduced from the sulphate is certainly very striking. Last of all and best of all we come to the determinations recently published by Nilson and Pettersson.* These chemists sought to use the sublimed chloride of glucinum, but found it to contain traces of lime derived from a glass tube. They finally resorted to the sulphate as the most available salt for their purposes. This, which they write Glj(SO4)3 121-120, and which we formulate as GISO4.4H2O, yields pure glucina upon strong ignition. The subjoined percentages of glucina were thus obtained: I4.171 I4. I69 I4. I60 I4. I76 Mean, I4. I69, 4-.0023 Hence G10 = 25.048, and Gl - 9.085, ~.0055. If 0 = 16, GI = 9.106. If SO3 80, then G1 = 9.096. If the oxide is G12 03, then the value G - 9.085, ~.0055 becomes Gl = 13.628, +.0082. It would be easy enough to combine this value for G1 with those derived from the experiments of the investigators previously cited, but it is hardly worth while. All the other estimations have such high probable errors that they would practically vanish from the general mean. Their influence would hardly extend to the third decimal place, and they may therefore be neglected. * Compt. Rend., 9I, I68. I880. 100 THE ATOMIC WEIGHTS. MAGNESIUM. There is perhaps no common metal of which the atomic weight has been subjected to closer scrutiny than that of magnesium. The value is low, and its determination should, therefore, be relatively free from many of the ordinary sources of error; it is extensively applied in chemical analysis, and ought consequently to be accurately ascertained. Strange discrepancies, however, exist between the results obtained by different investigators; so that the generally accepted figure cannot be regarded as absolutely free from doubt. The determinations of Berzelius* and other early chemists need not be here considered. Nor does the estimation made by Macdonnellt deserve more than a passing mention. Ile puts the atomic weight of magnesium at 23.9, but gives no details concerning his method of determination. The researches which we have to consider are those of Scheerer, Svanberg and Nordenfeldt, Jacquelain, Bahr, Marchand and Scheerer, and Dumas. Scheerer's method of investigation was exceedingly simple.$ He merely estimated the sulphuric acid in anhydrous magnesium sulphate, employing the usual process of precipitation as barium sulphate. I-Ie gives no weighings, but reports the percentages of SO, thus found. In his calculations, O - 100, S03 - 500.75, and BaO 955.29. It is easy, therefore, to recalculate the figures which he gives, so as to establish what his method really represents, viz., the ratio between the sulphates of barium and magnesium. Thus revised, his four analyses show that 100 parts of MgSO4 yield the following quantities of BaSO4: *Lehrbuch, 5 Aufl., Bd. 3, s. I227. t British Association Report, I852, part 2, p. 36. I Poggend. Annal., 69, 535. 1846. MAGNESIUM. 101 Per cent. SO8. 193.575 66.573 I93.677 66.608 193.767 66.639 I93.631 66.592 Mean, 193.6625, --.0274 Hence, using the atomic weights deduced in previous chapters for Ba, S, and 0, Mg = 24.544, +.0311. In a subsequent note* Scheerer shows that the barium sulphate of the foregoing experiments carried down with it magnesium salts in such quantity as to make the atomic weight of magnesium 0.39 too low. Corrected, Mg becomes - 24.545. The work of Bahr, of Jacquelain, and in part that of Svanberg and Nordenfeldt, also relates to the composition of magnesium sulphate. Jacquelain's experiments were as follows.t Dry magnesium sulphate was prepared by mixing the ordinary hydrous salt to a paste with sulphuric acid, and calcining the mass in a platinum crucible over a spirit lamp to constant weight and complete neutrality of reaction. This dry sulphate was weighed and intensely ignited three successive times. The weight of the residual MgO having been determined, it was moistened with sulphuric acid and recalcined over a spirit lamp, thus reproducing the original weight of MgSO,. Jacquelain's weighings for these two experiments show that 100 parts of MgO correspond to the quantities of MgSO4 given in the last column: 1.466 grm. MgSO4 gave.492 grm. MgO. 297.968.492" MgO " 1.466 MgSO4. 297.968 Jacquelain also made one estimation of sulphuric acid in the foregoing sulphate as BaSO4. His result, (1.464 grm. MgSO()4 2.838 grm. BaSO4,) reduced to the standard adopted in dealing with Scheerer's experiments, give for 100 parts of'CMgSO4, 193.852 BaS04. If this figure be given equal weight with a single experiment in Scheerer's series, * Poggend. Annal., 70, 407. t Ann. d. Chim. et Phys., 3 serie, 32, 202. 102 THE ATOMIC WEIGHTS. and combined with the latter, the mean will be 193.700, _+.0331. From this the atomic weight of magnesium becomes 24.244, -.033. This again, corrected according to Scheerer for the magnesium salts carried down by the barium sulphate, becomes 0.39 higher, or Mg = 24.283. Of course this correction, determined by Scheerer for a single experiment, can only be a rough approximation in a mean like the foregoing. It is better than no correction at all, the character of the error involved being known. Bahr's* work resembles in part that of Jacquelain. This chemist converted pure magnesium oxide into sulphate, and from the increase in weight determined the composition of the latter salt. From his weighings 100 parts of MgO equal the amounts of MgSO4 given in the third column: i.6938 grm. MgO gave 5.0157 grm. MgSO4. 296.122 2.0459 " 6.0648 " 296.437.o0784 " 3. I925 " 296.040 Mean, 296.200, ~.0815 About four years previous to the investigations of Bahr the paper of Svanberg and Nordenfeldtt appeared. These chemists started with the oxalate of magnesium, which was dried at a temperature of from 100~ to 105~0 until it no longer lost weight. The salt then contained two molecules of water, and upon strong ignition it left a residue of MgO. The percentage of MgO in the oxalate comes out as follows: 7.2634 grm. oxalate gave i.9872 grm. oxide. 27.359 per cent. 6.3795 I.7464 " 27.375 6.3653 1.7418 27-364 6.2216 " 1.7027 " 27.368 Mean, 27.3665, -4-.0023 In three of these experiments the MgO was treated with H2SO0, and converted, as by Jacquelain and by Bahr in their later researches, into MgSO4. One hundred parts of MgO gave of MgSO, as follows: Journ. fiir Prakt. Chem., 56, 310. 1852. t Journ. fiir Prakt. Chem., 45, 473. I848. MAGNESIUM. 103 1.9872 grm. MgO gave 5.8995 grm. MgSO4. 296.875 1.7464 " 5.1783 " 296.513 1-7418 5.1 666," 296.624 Mean, 296.671, +.072 We have now for this ratio between MgO and MgSO4 three series; not at all concordant. We may combine them, assigning to each of Jacquelain's two results a weight corresponding to one of Bahr's: Jacquelain 297.968, 4-.o999 Bahr 296.200, -!.0815 Svanberg and Nordenfeldt _____ 296.671, ~-.072 General mean 296.806, -.0475 In 1850 the elaborate investigations of Marchand and Scheerer* appeared. These chemists undertook to determine the composition of some natural magnesites, and, by applying corrections for impurities, to deduce from their results the sought for atomic weight. The magnesite chosen for the investigation was, first, a yellow, transparent variety from Snarum; second, a white opaque mineral from the same locality; and, third, a very pure quality from Frankenstein. In each case the impurities were carefully determined; but only a part of the details need be cited here. Silica was of course easily corrected for by simple subtraction from the sum of all of the constituents; but iron and calcium, when found, having been present in the mineral as carbonates, required the assignment to them of a portion of the carbonic acid. In the atomic weight determinations the mineral was first dried at 300~. The loss in weight upon ignition was then carbon dioxide. It was found, however, that even here a correction was necessary. Magnesite, upon drying at 300~, loses a trace of CO2, and still retains a little water; on the other hand, a minute quantity of CO2 remains even after ignition. The CO2 expelled at 300~ amounted in one experiment to.054 per cent.; that retained after calcination to.055 per cent. Both errors tend in the * Journ. fiur Prakt. Chem., 50, 385. 104 THE ATOMIC WEIGHTS. same direction, and increase the apparent percentage of MgO in the magnesite. On the yellow mineral from Snarum the crude results are as follows, giving percentages of MgO, FeO, and CO2 after eliminating silica: c02. gr0o. e O. 51.8958 47.3278.7764 51-8798 47-3393.7809 51.8734 47-3154.8I 12 51.8875 47-3372 -7753 Mean, 47.3299 4-.0037 After applying corrections for loss and retention of CO,, as previously indicated, the mean results of the foregoing series becomeC02. MgO. FeO. 51.9931 47.2743.7860 The ratio between the MgO and the CO2, after correcting for the iron, will be considered further on. Of the white magnesite from Snarum but a single analysis was made, which, for present purposes may be ignored. Concerning the Frankenstein mineral three series of analyses were executed. In the first series the following results were obtained: 8.996 grm. CO2 - 8.2245 grm. MgO. 47.760 per cent. MgO. 7.963,, 7.2775 " 47.76i 9.3265 " 8.529 c" 47-767 7.553 " 6.9095 " 47.775 Mean, 47.766, -.0022 This mean, corrected for loss of CO2 in drying, becomes'.81. I give series second with corrections applied: 6.8195 grm. MgCO3 gave 3.2500 grm. MgO. 47.658 per cent. I1.306I " 5-3849 " 47.628 9.7375 " 4.635 " 47-599 12.3887 " 5-9033 " 47.650 32-4I48,, I5.453 " 47.674 38.892 " 8.5366 " 47.663 26.5223 I2.6445 " 47.675 Mean, 47.650, o.0o69 MAGNESIUM. 105 The third series was made upon very pure material, so that the corrections, although applied, were less influential. The results were as follows: 4.2913 grm. MgCO3 gave 2.0436 grmin. MgO. 47.622 per cent. 27.8286 " I3.2539 " 47.627 " 14.6192 it 6.9692," 47.672 18.3085 it 8.7237 " 47.648 Mean, 47.642,.oo0077 In a supplementary paper* by Scheerer, it was shown that an important correction to the foregoing data had been overlooked. Scheerer, re-examining the magnesites in question, discovered in them traces of lime, which had escaped notice in the original analyses. With this correction the two magnesites in question exhibit the following mean composition: Snarum. Frankenstein. CO2__ __________ 52.131 52-338 MgO 46. 663 47-437 CaO __.430.225 FeO __ ____.776 I00.000 100.000 Correcting for lime and iron, by assigning each its share of C02, the Snarum magnesite gives as the true percentage of magnesia in pure magnesium carbonate, the figure 47.624. To this, without serious mistake, we may assign the weight indicated by the probable error, +.0037; the quantity previously deduced from the percentages of MgO given in the uncorrected analyses. From the Frankenstein mineral, similarly corrected, the final mean percentage of MgO in MgCO3 becomes 47.628. This, however, represents three series of analyses, whose combined probable errors may be properly assigned to it. The combination is as follows: * Ann. d. Chem. und Pharm., IIO, 240. 106 THE ATOMIC WEIGHTS. -+-.0022.- 0oo69 __.0077 Result, -4-.oo0020o, probable error of the general mean. We may now combine the results obtained from both magnesites: Snarum mineral_ -— _Per cent. MgO, 47.624,.-.0037 Frankenstein mineral __ " 47.628, +.0020 General mean___ " 47.627, 4-.oo18 The last investigation upon the atomic weight of magnesium which we have to consider is that of Dumas.* Pure magnesium chloride was placed in a boat of platinum, and ignited in a stream of dry hydrochloric acid gas. The excess of the latter having been expelled by a current of dry carbon dioxide, the platinum boat, still warni, was placed in a closed vessel and weighed therein. After weighing, the chloride was dissolved and titrated in the usual manner with a solution containing a known quantity of pure silver. The weighings which Dumas reports give, as proportional to 100 parts of silver, the quantities of MgCl, stated in the third column: 2.203 grm. MgCl. --- 4.964 grin. Ag. 44.380 2.5215 " 5.678 " 44.408 2.363 " 5-325 " 44-376 3.994 " 9.0I2 " 44-3I9 2.578 " 5.834 " 44. I89 2.872,, 6.502 it 44.171 2.080 " 4.7 IO " 44. 6 2.214,, 5.002, 44.262 2.o86 " 4.722 " 44. I76 1.688 " 3.823 " 44. I54 1.342,, 3.031 44.276 Mean, 44.26I, --.020 There are now before us the following ratios, from which to deduce the sought-for atomic weight: Ann. Chem. Pharm., I I3, 33. I86o. MAGNESIUM. 107 (I.) MgSO.: BaSO:: o00: 193.700, ___.033I (2.) MgO: MgSO4:: IOO: 296.806, 4-.0475 (3.) Per cent. of MgO in oxalate, 27.3665, -+.0023 (4.) Per cent. of MgO in carbonate, 47.627, --.00I8 (5.) Ag: MgCI2:: 100: 44.26I, ~.020 From these we find three values for the molecular weight of MgO: From (2)_-__ _ MgO = 40.587, -.0126 From (3) " -40.603, -.0069 From (4), --- 39.922, 4-.0030 General mean__ -. 40.o054, 4.0027 We have also three values for the atomic weight of magnesium: From molecular weight of MgO_ — _-_-Mg = 24.091, -.0044 From ratio (I,) corrected___._ ____ " - - 24.283, 0.o33 From ratio (5,) Dumas = 24.576, i-.o32 General mean _-__ ________ " - 24. 1o3, +.0043 Or, if O = 16, Mg becomes = 24.159. In this general mean all the determinations are included, good or bad. Dumas' result is unquestionably wrong; the error, probably, being due to the presence of oxychloride in the MgCl2 which was used. It is doubtful whether any precautions could have eliminated that error. If we take only Marchand and Scheerer's work on magnesium carbonate as having positive value, we shall get from their analyses the following result, viz: Mg = 23.959, +-.0046. Or, if 0 = 16, this becomes 24.014. The atomic weight of magnesium, therefore, varies'from the whole number 24, only within the ordinary limits of experimental error. 108 THE ATOMIC WEIGHTS. ZINC. The several determinations of the atomic weight of zinc are by no means closely concordant. The results obtained by Gay-Lussac * and Berzelius t were undoubtedly too low, and may be disregarded here. We need consider only the work done by Jacquelain, Favre, and Axel Erdmann. In 1842 Jacquelain published the results of his investigations upon this important constant.t In two experiments a weighed quantity of zinc was converted into nitrate, and that. by ignition in a platinum crucible was reduced to oxide. In two other experiments sulphuric acid took the place of nitric. As the zinc contained small quantities of lead and iron, these were estimated, and the necessary corrections applied. From the weights of metal and oxide given by Jacquelain the percentages have been calculated: Nitric Series. 9.917 grmin. Zn gave 12.3 38 grm. ZnO. 80.536 per cent. Zn. 9.809 1 I2.1800 " 80.534 Suiphuric Series. 2.398 " 2.978 grm. ZnO. 80. 524 3. I97 " 3.968 " 80. 570 Mean of all four, 80.541, -.007 Hence Zn = 66.072, ~.028. The method adopted by Axel Erdmann II is essentially the same as that of Jacquelain, but varies from the latter in certain important details. First, pure' zinc oxide was prepared, ignited in a covered crucible with' sugar, and then, to complete the reduction, ignited in a porcelain tube in a current of hydrogen. The pure zinc thus obtained was converted into oxide by means of treatment with nitric acid and sub* Memoire d'Arceuil, 2, I74. t Gilb. Annal., 37, 460. + Compt. Rend., I4, 636. [I Poggend. Annal., 62, 6II. Berz. Lehrb., 3, 1219. ZINC. 109 sequent ignition in a porcelain crucible. Erdmann's figures give us the following percentages of metal in the oxide: 80.247 80.257 80.263 80.274 Mean, 80.260, 4-.0037 Hence Zn = 64.9045, ~.019. If we combine the results of Jacquelain with those of Erdmann, we get a mean percentage of zinc, 80.324, +.0032; and an atomic weight of Zn - 65.168, +.018. The reason for the discordance between the two experimenters will be considered further along. Favre* employed two methods of investigation. First, zinc was dissolved in sulphuric acid, the hydrogen evolved was burned, and the weight of water thus formed was determined. To his weighings I append the ratio between metallic zinc and 100 parts of water: 25.389 grm. Zn gave 6.928 grm. H20. 366.469 30o.369 " 8.297, " 366.024 31.776 " 8.671 " 366.463 Mean, 366.319, -.o88 Hence Zn = 65.803, +-.020. The second method adopted by Favre was to burn pure zinc oxalate, and to weigh the oxide and carbonic acid thus produced. From the ratio between these two sets of weights the atomic weight of zinc is easily deducible. From Favre's weighings, if CO2 100, ZnO will be as given in the third column below: 7.796 grm. ZnO-= 8.365 grm. CO,. 93.I98 7.342 " 7.883 " 93 I37 5.2065 " 5.588," 93. I73 Mean, 93.I69, 4.012 Hence Zn = 65.8395, +.022. * Ann. Chim. Phys., (3,) io, I63- I844 110 THE ATOMIC WEIGHTS. A fourth combustion of the oxalate is omitted from the above series, having been rejected by Favre himself. In this the oxide formed was contaminated by traces of sulphide. The four values for zinc now before us are so discordant that a combination of them after the usual method can have only a trifling significance. The following is the result thus obtained: From Jacquelain's figures ___Zn = 66.072, -.028 From Favre's water series___ " - 65.803, --.020 From Favre's oxalate series__." - 65.8395, -.022 From Erdmann's figures, — " 64.9045, 4.019 General mean _. —- " = 65.557, 4-.01I It will be seen that three of these values agree tolerably well, placing the atomic weight of zinc in the neighborhood of 66, while the other is, in round numbers, about a unit lower. This lower figure, however, has the smallest probable error, and it will be found also, upon careful consideration, that it is less likely than the others to be vitiated by experimental inaccuracies. Both chemically and mathematically it is the best. Upon comparing Erdmann's results with those of Jacquelain two points are worth noticing: first, Erdmann worked with purer material than Jacquelain, although the latter applied corrections for the impurities which he knew were present; secondly, Erdmann calcined his zinc nitrate in a porcelain crucible, while Jacquelain used platinum.' In the latter case it has been shown that portions of zinc may become reduced and alloy themselves with the platinum of the crucible. Hence a lower weight of oxide from a given quantity of zinc, a higher percentage of metal, and an increased atomic weight. This source of constant error has undoubtedly affected Jacquelain's experiments, and vitiated his results. In Erdmann's work no such errors seem to be present. Over Favre's experiments Erdmann's have the important merit of silnplicity. In the latter it is difficult to detect sources of error; in the former it is easy. In Favre's water CADMIUM. 111 series it was essential that the hydrogen should first be thoroughly dried before combustion, and then that every trace of water formed should be collected. A trivial loss of hydrogen or of water would tend to increase the apparent atomic weight of zinc. In the combustion of the zinc oxalate equally great difficulties are encountered. Here a variety of errors are possible, such as are due, for exanple, to impurity of material, to imperfect drying of the carbon dioxide, and to incomplete collection of the latter. It may not be easy to prove that such errors actually did creep into Favre's work, and yet their possibility hinders us from absolutely accepting his results. All things considered, then, Erdmann's de-termination of the atomic weight of zinc is the one most entitled to credit, and must be taken for the present in lieu of the general mean deduced from all four of the values. This determination, Zn = 64.9045, -.019, becomes, if O = 16, 65.054. CADMIUM. The earliest determination of the atomic weight of this metal was by Stromeyer, who found that 100 parts of cadmium united with 14.352 of oxygen.* With our value for the atomic weight of oxygen these figures make Cd - 111.227. This result has now only a historical interest. The more modern estimates of the atomic weight of cadmium are four in number, by v. Hauer, Lenssen, Dumas, and Huntington. Of these that by v. Hauer t comes first in chronological order. Ie heated pure anhydrous cadmium sulphate in a stream of dry hydrogen sulphide, and weighed the cadmium sulphide thus obtained. His results * See Berz. Lehrbuch, 5th Ed., 3, I219. t Journ. fiir Prakt. Chem., 72, 350. I857. 112 THE ATOMIC WEIGHTS. were as. follows, with the percentage of CdS in CdSO, therefrom deduced: 7.7650 grm. CdSO4 gave 5.3741 grm. CdS. 69.209 per cent. 6.6o86 " 4.5746 " 69.222 " 7.3821,, 5.1117 c" 69.245 " 6.8377 " 4.7336 " 69.228 it 8. I956 " 5.6736 " 69.227 " 7.6039 " 5.2634 " 69.220 7- I415 4.943,1 " 69.217 " 5.8245 " 4.0335 " 69.251 " 6.8462 4.7415 " 69.257 " Mean, 69.231, -4-.0042 Lenssen* worked upon pure cadmium oxalate, handling, however, only small quantities of material. This salt, upon ignition, leaves the following percentages of oxide:.5128 grm. oxalate gave.3281 grm. CdO. 63.982 per cent..6552,.4193 " 63-996.40I 7." 2573 " 64.053 Mean, 64.010, -.014 Dumast dissolved pure cadmium in hydrochloric acid, evaporated the solution to dryness, and fused the residue in hydrochloric acid gas. The cadmium chloride thus obtained was dissolved in water and titrated with a solution of silver after the usual manner. From Dumas' weighings I calculate the ratio between CdCl and 100 parts of silver: 2.369 grm. CdC12 - 2.791 grm. Ag. 84.880 4.540 " 5.348 " 84.892 6. I177 7.260 " 85.803 2.404 2.841 " 84.618 3.5325 " 4. I66 " 84794 4.042 4.767 84.79I Mean, 84.843, -.026 Latest of all comes Huntington's l work, done under the direction of Professor J. P. Cooke. Bromide of cadmium * Journ. fiir Prakt. Chem., 79, 281. I86o. - Ann. Chem. Pharm., I I3, 27. I863. + Proc. Amer. Acad., I88I. CADMIUM. 113 was prepared by dissolving the carbonate in hydrobromic acid, and the product, dried at 200~, was purified by sublimation in a porcelain tube. Upon the compound thus obtained two series of experiments were made. In one series the bromide was dissolved in water, and a quantity of silver not quite sufficient for complete precipitation of the bromine was then added in nitric acid solution. After the precipitate had settled, the supernatant liquid was titrated with a standard solution of silver containing one gramme to the litre. The precipitate was washed by decantation, collected by reverse filtration, and weighed. To the weighings I append the ratio between CdBr2 and 100 parts of silver bromide: 1.5592 grm. CdBr2 gave 2.1529 grm. AgBr. Ratio, 72.423 *3-7456 it 5. 724 " 72.415 2.4267 " 3-35 11 72.415 NC 3.6645 5.o0590 " 72.435 * 3.7679 5.20I6 " 72-437 2.7938 " 3.8583 " 72.410 * 1.9225 " 2.6552 " 72.405 3.4473 " 4-7593 " 72-433 Mean, 72.42i6, ~.0028 The second series was like the first, except that the weight of silver needed to effect precipitation was noted, instead of the weight of silver bromide formed. In the experiments marked with an asterisk, both the amount of silver required and the amount of silver bromide thrown down were determined in one set of weighings. The third column gives the CdBr2 proportional to 100 parts of silver: *3.7456 grin. CdBr2 - 2.9715 grm. Ag. 126.051 5.0270 3.9874 126.072 * 3.6645 2.9073 " I26.045 * 3.7679 2.9888 "26.067 * 1.9225 1".5248 " 126.082 2.9101 " 2.3079 "26.093 3.65IO "0 2.8951 " I26. IIO 3.9782 " 3 I551 I26.088 Mean, I26.076, 4-.0052 8 114 THE ATOMIC WEIGHTS. From the first series...CdBr2 = 271.498,.o032 From the second series_ " _ 271.505, 4-.027 General mean__ " = 271.502, -.0215 Hence Cd = 111.966, ~.043. According to Huntington's own calculations these experiments fix the ratio between silver, bromine, and cadmium as Ag: Br: Cd:: 108: 80: 112.31. This result militates strongly against Prout's hypothesis. Upon combining all the determinations we get the following result: v. Hauer.-...........Cd = 11.684, -.040 Lenssen.............. _ ____= II 11.803, --.o62 Dumas.______ ____.____ " I I.969, ~.o65 Huntington _.__ —____ " I I I.966, _.040 General mean______ " =III.835, -.024 Or, if O = 16, then Cd - 112.092. It will be seen that Dumas and Huntington's determinations, both made with haloid salts of cadmium, agree with wonderful closeness, and so confirm each other. On the other hand, v. Hauer's data give a value for the atomic weight of cadmium which is much lower. Apparently, v. Hauer's method was good, and the reason for the discrepancy remains to be discovered. Until it is ascertained I prefer to use the above mean value for Cd, rather than to adopt one investigation and reject the others. MERCURY. In dealing with the atomic weight of mercury we may reject the early determinations by Sefstr6m* and a large part of the work done by Turner.t The latter chemist, in addition to the data which will be cited below, gives figures * Sefstr6m. Berz. Lehrb., 5th Ed., 3, 1215. Work done in 1812. t Phil. Trans., I833, 531-535. MERCURY. 115 to represent the percentage composition of both the chlorides of mercury; but these results are neither reliable nor in proper shape to be used. First in order we may consider the percentage composition of mercuric oxide, as established by Turner and by Erdmann an'd Marchand. In both investigations the oxide was decomposed by heat, and the mercury was accurately weighed. Gold leaf served to collect the last traces of mercurial vapor. Turner gives four estimations.* Two represent oxide obtained by the ignition of the nitrate, and two are from commercial oxide. In the first two the oxide still contained traces of nitrate, but hardly in weighable proportions. A. comparison of the figures from this source with the others is sufficiently conclusive on this point. The third column represents the percentage of mercury in HgO: 144.805 grains Hg = I11.54 grains 0. 92.6I9 per cent. I25.980 " iO.o8 " 92.592 173.56I " I3.82 " 92.625 I I4.294,, 9. IoI," 92.620 Mean, 92.614, 4-.0050 In the experiments of Erdmann and Marchandt every precaution was taken to ensure accuracy. Their weighings, reduced to a vacuum standard, give the subjoined percentages: 82.0079 grm. HgO gave 75.9347 grin. Hg. 92.594 per cent. 51.o0320,, 47.2538 " 92.597 84-4996 It 78.2501 92.604 44.6283 it 41.3285 " 92.606 I I8.4066 I" I09.6408 " 92.597 Mean, 92.5996, --.0015 Combining, we have: Turner _____.___ —. _ 92.614, -.0050 Erdmann and Marchand ____ 92.5996, -.ooI5 General mean-..___-__ 92.601,.I0014 * Phil. Trans., 1833, 531-535. J Journ. fiir Prakt. Chem., 3I, 395. I844. 116 THE ATOMIC WEIGHTS. With a view to establishing the atomic weight of sulphur Erdmann and Marchand also made a series of analyses of pure mercuric sulphide. These data are now best available for discussion under mercury. The sulphide was mixed with pure copper and ignited; mercury distilling over and copper sulphide remaining behind. Gold leaf' was used to retain traces of mercurial vapor, and the weighings were reduced to vacuum: 34.3568 grm. HgS gave 29.6207 grm. Hg. 86.215 per cent. Hg. 24.8278 it 21.40295 " 86.206 37.2177 32.08416 " 86.207 80.764I " 69.6372 " 86.223 " Mean, 86.2127, 4-.0027 For the percentage of mercury in mercuric chloride we have data by Turner, Millon, and Svanberg. Turner,* in addition to some precipitations of mercuric chloride by silver nitrate, gives two experiments in which the compound was decomposed by pure stannous chloride, and the mercury thus set free was collected and weighed. The results were as follows: 44.782 grains Hg- 15.90 grains C1. 73-798 per cent. 73.o09 " 2597 " 73.784 " Mean, 73.791,.0o05 Millont purified mercuric chloride by solution in ether and sublimation, and then subjected it to distillation with lime. The mercury was collected as in Erdmann and Marchand's experiments. Percentages of metal as follows: 73-87 73.8I 73.83 73.87 Mean, 73.845, ~.I00 Svanberg,T following the general method of Erdmahn * Phil. Trans., I833, 53I-595. t Ann. Chim. Phys., (3,) I8, 345 I846. $ Journ. fur Prakt. Chem., 45, 472. 1848. CHROMIUM. 117 and Marchand, made three distillations of mercuric chloride with lime, and got the following results: 12.048 grm. HgC12 gave 8.889 grm. Hg. 73-780 per cent. I2.529 " 9.2456 " 73.794 12.6491 " 9-3363 " 73.8Io Mean, 73.795, 4-.oo6 Combining these series we have: Turner ____ 73.79I, -4-.005 Millon- _73.845, 4-.00 Svanberg 73.795, 4-.006 General mean_____ - -___ 73.798, -.o0034 In this mean Turner's figures undoubtedly receive undue weight, for, on experimental grounds, they are probably inferior to both of the other series. It is better, however, that the general mean should remain as it is, than that I should deal arbitrarily with any of the data. We now have three figures to calculate from: Per cent. of Hg in HgO- ____ 92.601, -.00I4 c" HgS ___.- __ 86.2127, --.0027 As HgC12 -_ —-- 73.798, -.0034 These give us three values for the atomic weight of mercury and a general mean as follows: From HgO-_... _____....Hg = 199.786, 4-.059 From HgS __.________ " - 200.016, -+.o88 From HgC12 - = 199.239, +-.o86 General mean " I99.712, ~-.042 If 0 = 16, then this becomes 200.171. CHROMIUM. Concerning the atomic weight of chromium there has been much discussion, and many experimenters have sought to establish the true value. The earliest work upon it hav 118 THE ATOMIC WEIGHTS. ing any importance was that of Berzelius,* in 1818 and 1826, which led to results much in excess of the correct figure. Iis method consisted in precipitating a known weight of lead nitrate with an alkaline chromate and weighing the lead chromate thus produced. The error in his determination arose from the fact that lead chromate, except when thrown down from very dilute solutions, carries with it minute quantities of alkaline salts, and so has its apparent weight notably increased. When dilute solutions are used, a trace of the precipitate remains dissolved, and the weight obtained is too low. In neither case is the method trustworthy. In 1844 Berzelius' results were first seriously called in question. The figure for chromium deduced from his experiments was somewhat over 56; but Peligott now showed, by his analyses of chromous acetate and of the chlorides of chromium, that the true number was near 52.5. Unfortunately, Peligot's work, although good, was published with insufficient details to be useful here. For chromous acetate he gives the percentages of carbon and hydrogen, but not the actual weights of salt, carbon dioxide, and water from which they were calculated. His figures vary considerably moreover; enough to show that their mean would carry but little weight when combined with the more explicit data furnished by other chemists. Jacquelain'sl work we may omit entirely. He gives an atomic weight for chromium which is notoriously too low, and prints none of the numerical details upon which his result rests. The researches which particularly command our attention are those of Berlin, Moberg, Lefort, Wildenstein, Kessler, and Siewert. Among the papers upon the atomic weight under consideration that by Berlin is one of the most important.l1 His starting point was normal silver chromate; but in one ex* Schweigg. Journ., 22, 53, and Poggend. Annal., 8, 22. t Compt. Rend., 19, 609 and 734; 20, 1187; 21, 74. + Compt. Rend., 24, 679. I847. 1[ Journ. fiir Prakt. Chem., 37, 509, and 38, I49. I846. CHROMIUM. 119 periment the anhydrochromate Ag2 Cr2 0 was used. These salts, which are easily obtained in a perfectly pure condition, were reduced in a large flask by means of hydrochloric acid and alcohol. The chloride of silver thus formed was washed by decantation, dried, fused, and weighed without transfer. The united washings were supersaturated with ammonia, evaporated to dryness, and the residue treated with hot water. The resulting chromic oxide was then collected upon a filter, dried, ignited, and weighed. The results were as follows: 4.6680 grm. Ag2CrO4 gave 4.027 grm. AgC1 and I.0754 grm. Cr203. 3.4568 2.983 ".7960 2.5060 " 2. I605 ".5770 2. 1530 1.8555 ".4945 4.3335 grm. Ag2Cr207 gave 2.8692 " 1.5300 From these weighings three values are calculable for the atomic weight of chromium. The three ratios upon which these values depend we will consider separately; taking first that between the chromic oxide and the original silver salt. In the four analyses of the normal chromate the percentages of Cr203 deducible from Berlin's weighings are as follows: 23.037 23.027 23.025 22.968 Mean, 23.014, — _.I0I And from the single experiment with Ag2Cr207 the percentage of Cr2 03 was 35.306. For the ratio between Ag2Cr04 and AgCl, putting the latter at 100, we have for the former: II5.917 I 5.883 115.992 16.o33 Mean, I I5.956, -4-.023 120 THE ATOMIC WEIGHTS. In the single experiment with anhydrochromate 100 AgC1 is formed from 151.035 Ag2Cr207. Finally, for the ratio between AgC1 and Cr,03, the five experiments of Berlin give, for 100 parts of the former, the following quantities of the latter: 26.705 26.685 26.707 26.650 26.662 Mean, 26.682, -4-.0076 These results will be discussed in connection with the work of other investigators at the end of this chapter. In 1848 the researches of Moberg* appeared. His method simply consisted in the ignition of anhydrous chromic sulphate and of ammoniacal chrome alum, and the determination of the amount of chromic oxide thus left as residue. In the sulphate, Cr2(SO4)3, the subjoined percentages of Cr2 03 were found. The brackets indicate two different samples of material, to which, however, we are justified in ascribing equal value:.542 grm. sulphate gave.212 grm. Cr203. 39.1I4 per ent.) 1.337 ".523,, 39 117 " [.5287 ".207 " 39.I53 " I.033.406 " 39-303 ".868.". 34I " 39.286 Mean, 39. I946, 4-.0280 From the alum, (NH14)2Cr2(S04)2.24H2,O, we have these percentages of Cr2 03. The first series represents a salt long dried under a bell jar at a temperature of 18~. The crystals taken were clear and transparent, but may possibly have lost traces of water,t which would tend to increase the atomic weight found for chromium. In the second series the salt was carefully dried between folds of filter paper, and *Journ. fiir Prakt. Chem., 43, II4.'- This objection is suggested by Berlin in a short note upon Lefort's paper. Journ. fiir Prakt. Chem., 71, I91. CHROMIUM. 121 results were obtained quite near those of Berlin. Both of these series are discussed together, neither having a remarkable value: 1.3185 grm. alum gave.213 grm. Cr203. i6.155 per cent. ].7987 ".129 " I6.151 I.oI85 4".I645 " I6. I5I " 1.0206 " i1650 " I6.I67.8765 " 1420 " I6.20I ".7680 ".1242 " I6.I72 " I.6720 ".2707 " I6.I9 ".5410.0875 " 6.I74 " 1.2010.1940 " 6.153 " I.OOIO ".i620 " 6. I84 ".7715.I235 6.007 " I.374.2200 I" 6.012 " } Mean, I6.I43, 4-.0125 The determinations made by Lefort* are even less valuable than those by Moberg. This chemist started out from pure barium chromate, which, to thoroughly free it from moisture, had been dried for several hours at 250~. The chromate was dissolved in pure nitric acid, the barium thrown down by sulphuric acid, and the precipitate collected upon a filter, dried, ignited, and weighed in the usual manner. The natural objection to the process is' that traces of chromium may be carried down with the sulphate, thus increasing its weight. In fact, Lefort's results are somewhat too high. Calculated from his weighings, 100 parts of BaSO4 correspond to the amounts of BaCrO4 given in the third column: I.2615 grm. BaCrO4 gave. I555 grm. BaSO4. 109.174 1.5895 " 1.4580 " Io9.0I9 2.3255 2. I1340 " 108.974 3.0390 " 2.7855 " 109. 101 2.3480 " 2. I590 " Io08.754 1.4230 1 1.3060 i' I08.708. I975 " I.I005 " Io8.814 3.4580 cc 3. I690 IO 9.II9 2.0130 cc 1.8430 t 1I09.224 * Journ. fUr Prakt. Chem., 51, 26I. I850. 122 THE ATOMIC WEIGHTS. 3.5570 grm. BaCrO4 gave 3.27IO grm. BaSO4. 108.744 1.6470,, 1.5060," 109.363 1.8240 it 1.6725, I09.o058 1.6950 " I-5560 " Io8.933 2.5960,, 2.3870 I" 108.756 Mean, IO8.9815, +.0369 Wildenstein,* in 1853, also made barium chromate the basis of his researches. A known weight of pure barium chloride was precipitated by a neutral alkaline chromate, and the precipitate allowed to settle until the supernatant liquid was perfectly clear. The barium chromate was then collected on a filter, washed with hot water, dried, gently ignited, and weighed. Here again arises the objection that the precipitate may have retained traces of alkaline salts, and again we find deduced an atomic weight which is too high. One hundred parts BaCrO4 correspond to BaC12 as follows: 81.87 8I.57 81.80 81.75 81.6i 8i.66 81.78 81.83 81.52 8i.66 81.84 81.80 8I.85 8i.66 8I.70 81.85 81.68 8I.57 81.54 81.83 8i.66 81.71 8I.55 8I.63 8I.8I 8I.56 81.86 81.58 8I.54 81.67 8i.68 8i.84 Mean, 81.702, ~.014 Next in order we have to consider two papers by Kessler, who employed a peculiar volumetric method entirely his own. In brief, he compared the oxidizing power of potassium anhydrochromate with that of the chlorate, and from * Journ. fiir Prakt. Chem., 59, 27. CHROMIUM. 123 his observations deduced the ratio between the molecular weights of the two salts. In his earlier paper* the mode of procedure was about as follows: The two salts, weighed out in quantities having approximate chemical equivalency, were placed in two small flasks, and to each was added 100 cc. of a ferrous chloride solution and 30 cc. hydrochloric acid. The ferrous chloride was added in trifling excess, and, when action ceased, the amount unoxidized was determined by titration with a standard solution of anhydrochromate. As in each case the quantity of ferrous chloride was the same, it became easy to deduce from the data thus obtained the ratio in question. I have reduced all of his somewhat complicated figures to a simple common standard, and give below the amount of chromate equivalent to 100 of chlorate: I20. II8 120.37I 120.138 120.096 120.241 120. I81 Mean, 120.191, 4-.028 In his later papert Kessler substituted arsenic trioxide for the iron solution. In one series of experiments the quantity of anhydrochromate needed to oxidize 100 parts of the arsenic trioxide was determined, and in another the latter substance was similarly compared with the chlorate. The subjoined columns give the quantity of each salt proportional to 100 of As, 03: K, Cr, 07. KC03. 98.95 4. I56 98.94 41.116 99. I7 41.200 98.98 41.255 99.08 41.201 99.15 41.086 4I.I99 Mean, 99.045, 4-.028 41.224 * Poggend. Annal., 95, 208. I855. t Poggend. Annal., II3, I37. I86I. 124 THE ATOMIC WEIGHTS. KCO03. 41.16i 4II93 4I1I49 41. I 26 Mean,' 41.172, --.009 From the data given in the earlier paper, if we use our recent values for chlorine, potassium, and oxygen, K2Cr207 = 293-937, ~_.o86 And from the later, =- 294. I59, -. I I9 General mean,._ 294.013, -.o697 Finally, we come to the determinations published by Siewert,* whose work does not seem to have attracted general attention. He, reviewing Berlin's work, found that upon reducing silver chromate with hydrochloric acid and alcohol, the chromic chloride solution always retained traces of silver chloride dissolved in it. These could be precipitated by dilution with water; but, in Berlin's process, they naturally came down with the chromium hydroxide, making the weight of the latter too high. Hence too large a value for the atomic weight of chromium. In order to find a more correct value Siewert resorted to the analysis of sublimed, violet, chromic chloride. This salt he fused with sodium carbonate and a little nitre, treated the fused mass with water, and precipitated from the resulting solution the chlorine by silver nitrate in presence of nitric acid. The weight of the silver chloride thus obtained, estimated after the usual manner, gave means for calculating the atomic weight of chromium. His figures, reduced to a common standard, give, as proportional to 100 parts of chloride of silver, the quantities of chromic chloride stated in the third of the subjoined columns: * Zeitschrift Gesammt. Wissenschaften, I7, 530. I86I. CHROMIUM. 125.2367 grn. Cr2C16 gave.6396 grin. AgC1. 37.007.2946.. 7994 " 36.853.2593,. 7039 " 36.838 ~4935 1 3395 " 36.842.5850 1.5884 " 36.830.6511,, 1.7668I " 36.852.5503,, 1.49391 i" 36.836 Mean, 36.865, _4-.oi58 The first of these figures varies so widely from the others that we are justified in rejecting it; in which case the mean becomes 36.842, -.0031. Siewert also made two analyses of silver anhydrochromate by the following process. The salt, dried at 120~, was dissolved in nitric acid. The silver was then thrown down by hydrochloric acid, and, in the filtrate, chromium hydroxide was precipitated by ammonia. Reduced to a uniform standard, we find from his results, corresponding to 100 parts of AgC1, Ag2 Cr,07, as in the last column:.7866 grm. Ag2Cr207 gave.52202 AgCL and.2764 Cr203. I50.684 I.o89g ".72249 ".3840 1 50.729 Mean, 150.706, 4-.015 Giving Berlin's single estimation equal weight with one of these, and combining, we get a general mean of 150.816, -.074. Siewert's percentages of Cr203 obtained from Ag2Cr2 0 7, are as follows, calculated from the above weighings. 35. I39 35.262 Mean, 35.2005, --.0415 Combining, as before, with Berlin's single result, giving the latter equal weight with one of these, we have a general mean of 35.236, -.0335. For the ratio between silver chloride and chromic oxide, Siewert's two analyses of the anhydrochromate come out as follows. For 100 parts of AgCl we have of Cr2 03: 126 THE ATOMIC WEIGHTS. 52.948 53. 150 Mean, 53.049, _-.o68 This figure, reduced to the standard of Berlin's work on the monochromate, becomes 26.525, -4-.034. Berlin's mean was 26.682, -.0076. The two means, combined, give a general mean of 26.676, -i.074. We may now consider the ratios before us, which are as follows: (I.) Percentage Cr20O from Ag2CrO4, 23.014, -+-.OII (2.) Percentage Cr203 from Ag2Cr2O7, 35.236, ___.0335 (3.) AgCl: Ag2CrO4:: I00: 115.956, 4-.023 (4.) AgC1: Ag2Cr2O7:: oo00: 150.816, -.074 (5.) AgCl: Cr203:: Ioo: 26.676, -+.0074 (6.) Percentage Cr203 in chromic sulphate, 39. 946, 4-.0280 (7.) Percentage Cr203 in ammonia chrome alum, I6.143, 4-.0125 (8.) BaSO4: BaCrO4:: Ioo: 08.9815, 4-.0369 (9.) BaCrO4: BaC12:: Ioo: 81.702, 4-.014 (io.) Molecular weight of K2Cr207, 294.013, ~-.0697 (I.) AgCl: CrCl3:: 1oo: 36.842, ~-.0031 From these ratios we can at once deduce five values for the molecular weight of Cr203, as follows: From (I) --- Cr203 I52.612, 4-.074 " (2)_......_...... " =I51.905, 4-.i65 c(5c ).............._ " -1 52.634, +-.044 " (6)____ _- " 1 54.464, 4 -I35 " (7) "I= 154.512, 4-.125 General mean___ " = I52.855, 4.034 For barium chromate we get two values: From (8) ----— _-_ —— BaCrO4 = 253.494, 4-.094 (9) —----------- = 253.976, -.067 General mean__ _ " = 253.816, -.054 From (3) we get Ag2CrO4 = 331.739, ~-.070 " (4) " Ag2Cr2O7 = 431.470, 4-.215 "(II) " CrC1 = I58. I02, 4-.oi8 Finally, from these intermediate data we derive six values for the atomic weight of chromium: MANGANESE. 127 From BaCrO4 - __Cr - 53.200, ~-.o64 Cr203 --- " = 52.482, -.oI8 Ag2CrO4 _ ___ — " —- 52.536, -.074, Ag2Cr207__ " = 52.188, -4-.I09 " K2Cr2O_ = 52. I16, 4.078 IC CrC3____ " 51.992, 4-.047 General mean _ " = 52.453, ~-.OI5 Or, if O = I6-____. " = 52.574 On account of the wide discrepancies between different data, and of the known constant errors vitiating some of the series of experiments, the foregoing general mean can have but little real value. In fact, a careful consideration of all the work represented in it will show that the most accurate estimate of the atomic weight of chromium must be deduced from the experiments of either Berlin, Kessler, or Siewert. Berlin's figures, taken by themselves, and combined, give, if the single analysis of silver anhydrochromate be assigned equal weight with a single analysis in the monochromate series, Cr = 52.389, -.019; or, if O - 16, Cr - 52.511. Siewert's results, both for chromic chloride and the silver anhydrochromate, properly combined, give Cr = 52.009, -.025. If O = 16, this value becomes Cr = 52.129. In brief, the atomic weight of chromium may be nearly 52.5, or it may be 52. Only a revision of all the experiments could enable us to decide positively between these values. But as Siewert has pointed out probable sources of error in Berlin's work, I am inclined to give preference to the lower value. MANGANESE. Rejecting the early experiments of J. Davy and of Arfvedson, the first determinations of the atomic weight of manganese which we encounter are those of Turner* and of Berzelius.t Both of these chemists used the same method. * Trans. Roy. Soc. Edin., II, 143. I83I. t Lehrbuch, 5th Ed., 3, I224. 128 THE ATOMIC WEIGHTS. The chloride of manganese was fused in a current of dry hydrochloric acid, and subsequently precipitated with a solution of silver. From the subjoined weighings I calculate the ratio given in the third column between MnCl2 and 100 parts of AgCl: 4.20775 grm. MnCI2 = 9.575 grm. AgC1. 43-945 Berzelius. 3.063 t =_ 6.96912 " 43-9501 12.47 grains MnC1, - 28.42 grains AgC1. 43.878-Turner. Mean, 43.924, 4-.015 Hence the molecular weight of MnCl2 is 125.662, -+-.045. Many years later Dumas * also made the chloride of manganese the starting point of some atomic weight determinations. The salt was fused in a current of hydrochloric acid, and afterwards titrated with a standard solution of silver in the usual way. 100 parts of Ag are equivalent to the quantities of MnCl2 given in the third column: 3.3672 grin. MnC12 = 5.774 grm. Ag. 58.317 3.0872 5.293," 58.326 2.9671 5.o0875 c 58.321 1. 1244 " 1.928 " 58.320 1.3I34 2.251 " 58.321 Mean, 58.321, ~.OOI Hence MnC1, = 125.594, -.011. This, combined with Berzelius and Turner's figures, gives MnCl2 - 125.598, +.011. And Mn = 54.858, -.031. An entirely different method of investigation was followed by v. Hauer,t who, as in the case of cadmium, ignited the sulphate in a stream of sulphuretted hydrogen, and determined the quantity of sulphide thus formed. I subjoin his weighings, and also the percentage of MnS in MnSO4 as calculated from them: * Ann. Chem. Pharm., I 3, 25. I860. t Journ. fiir Prakt. Chem., 72, 360. I857. AIAN^GANESE. 129 4.0626 grm. MnSO4 gave 2.3425 grm. MnS. 57.660 per cent. 4.9367 " 2.8442 57.613 5.2372 " 3.0192 " 57.649 7.0047 " 4.0347 " 57.600 " 4.9175 " 2.8297 " 57-543 4.8546,, 2.7955 " 57.585 4-9978 " 2.8799 " 57.625 4.6737 2.6934' 57.629 4.7240 2.7I97 " 57-572 Mean, 57.608, -.0oo8 Hence Mn = 54.785, +.031. This method of v. Hauer's, which seemed to give good results with cadmium, is, according to Schneider,* inapplicable to manganese; for the reason that the sulphide of the latter metal is liable to be contaminated with traces of oxysulphide. Such an impurity would bring the atomic weight out too high. The results of two different processes, one carried out by himself and the other in his laboratory by Rawack, are given by Schneider in this paper. Rawack reduced manganoso-manganic oxide to manganous oxide by ignition in a stream of hydrogen, and weighed the water thus formed. From his weighings I get the values in the third column, which represent the Mn3 04 equivalent to one gramme of water: 4.I49 grm. Mn,04 gave 0.330 grm. H20. I2.5727 4.649 ".370 " 12.5643 6.8865.5485 " 12.5552 7-356.5855 " 12.5636 8.9445.7I35 " 12.5361 11.584.9225 " 12.5572 Mean, 12.5582, -.0034 Hence Mn = 53.911, -.026. Here the most obvious source of error lies in the possible loss of water. Such a loss, however, would increase the apparent atomic weight of manganese; but we see that the value found is much lower than that obtained either by Dumas or v. Hauer. * Poggend. Annal., 107, 605. 9 130 THE ATOMIC WEIGHTS. Schneider himself effected the combustion of manganous oxalate with oxide of copper. The salt was not absolutely dry, so that it was necessary to collect both water and carbon dioxide. Then, upon deducting the weight of water from that of the original material, the weight of anhydrous oxalate was easily ascertained. Subtracting from this the CO2, we get the weight of Mn. If we put CO2, 100, the quantities of manganese equivalent to it will be found in the last column: 1.5075 grm. oxalate gave.306 grm. H20 and.7445 grm. CO2. 6i.3835 2.253 ".4555 " 1.1135 " 6I.429I 3. I935 ".652 " 1.5745 " 61.4163 5.073 I.028 " 2.507 " 61.3482 Mean, 61.3943, -4-.o0122 Hence Mn - 53.904, -.014. This result agrees beautifully with the value calculated from Rawack's experiments. Now to combine the four independent values which we have thus far obtained: From MnC12 _________Mn = 54.858, 4-.o03 MnSO___ _- " 54.785, - 03I MnO4 __-_____ " = 53.9II, 4-.o26, MnC204 " 53-904, -.014 General mean ____ " = 54.I28, ~-.OII If O = I6. —---—. " = 54.251 The considerations already cited, however, go to show that this general mean must be slightly affected by some plus constant error. It is probable, therefore, that a more correct figure will result from rejecting the first and second values in the above combination, and taking the data furnished by Rawack and Schneider alone. Combining their figures, we get as follows. Mn = 53.906, —.012. Or, if O - 16, Mn = 54.029. Since the foregoing calculations were made Dewar and Scott* have reported the following experiments. From the * Nature, Sept. 15, I88I, p. 470. IRON. 131 complete analysis of silver permanganate, putting Ag = 108 and 0 = 16, they find in three estimations Mn = 55.51, 54.04, and 54.45. From the analysis of pure MnO2, made from the nitrate, Mn = 53.3 to 53.6. Up to the date of writing a detailed account of the methods employed has not been published. IRON. The atomic weight of iron has been determined almost exclusively from the composition of ferric oxide. Beyond this there are only a few comparatively unimportant experiments by Dumas relative to ferrous and ferric chlorides. Most of the earlier data relative to the percentage of metal and oxygen in ferric oxide we may reject at once, as set aside by later investigations. Among this no longer valuable material there is a series of experiments by Berzelius, another by D6bereiner, and a third by Capitaine. The work done by Stromeyer and by Wackenroder was probably good, but I am unable to find its details. The former found 30.15 per cent. of oxygen in the oxide under consideration, while Wackenroder obtained figures ranging from a minimum of 30.01 to a maximum of 30.38 per cent.* In 1844 Berzelius t published two determinations of the ratio in question. He oxidized iron by means of nitric acid, and weighed the oxide thus formed. He thus found that when O = 100 Fe - 350.27 and 350.369. Hence the following percentages of Fe in Fe,,03. 70.018 70.022 Mean, 70.020, -.0013 About the same time Svanberg and Norlin: published * For additional details concerning these earlier papers I must refer to Oudemans' monograph, pp. I40, I4I. t Ann. Chem. Pharm., 50, 432. Berz. Jahresb., 25, 43. 1 Berzelius' Jahresbericht, 25, 42. 132 THE ATOMIC WEIGHTS. two elaborate series of experiments; one relating to the synthesis of ferric oxide, the other to its reduction. In the first set pure piano-forte wire was oxidized by nitric acid, and the amount of oxide thus formed was determined. The results were as follows: 1.5257 grm. Fe gave 2.1803 grm. Fe,03. 69.977 per cent. Fe. 2.4051," 3.4390 c 69.936, 2.3212 " 3.3194 " 69.928 " 2.32175," 3.3183 " 69.968 " 2.2772 " 3.2550 " 69.960 " 2.4782 " 3.54I8 " 69.970 2.3582 " 3.3720 " 69.935 Mean, 69.9534, -.0050 In the second series ferric oxide was reduced by ignition in a current of hydrogen, yielding the subjoined percentages of metal: 2.98353 grm. Fe203 gave 2.08915 grm. Fe. 70.025 per cent. 2.41515 i 1.69io " 70.05 2.99175 " 2.09455 " 70.014 3.5783 " 2.505925 " 70.030 4. I922 " 2.9375 " 70.072 3-IOI5 " 2.17275 " 70.056 " 2.6886 " 1.88305 70.036 Mean, 70.0354, -.0055 It is evident that one or both of these series must be vitiated by constant errors, and that these probably arise from impurities in the materials employed. Impurities in the wire taken for the oxidation series could hardly have been altogether avoided, and in the reduction series it is possible that weighable traces of hydrogen may have been retained by the iron. At all events it is probable that the errors of both series are in contrary directions, and, therefore, in some measure compensatory. In 1844 there was also published an important paper by Erdmann and Marchand.* These chemists prepared ferric oxide by the ignition of pure ferrous oxalate, and submitted * Journ. fir Prakt. Chem., 33, I. IRON. 133 it to reduction in a stream of hydrogen. Two sets of results were obtained with two different samples of ferrous oxalate, prepared by two different methods. For present purposes, however, it is not necessary to discuss these sets separately. The percentages of iron in Fe,03 come out as follows: 70o.03 1 69.962 69.979 A. 70.030 69.977 70~044 70o.05 B. 70.055 J Mean, 70.0094, 1-.0080 In 1850 Maumene's* results appeared. He dissolved pure iron wire in aqua regia, precipitated with ammonia, filtered off the precipitate, washed thoroughly, ignited, and weighed, after the usual methods of quantitative analysis. The percentages of Fe in Fe,O, are given in the third column: 1.482 grm. Fe gave 2.117 grm. Fe20O. 70.005 per cent. 1.452 " 2.074 " 70.010 " 1.3585 I" 1.94I,, 69. 990, 1.420 " 2.0285 " 70.002 1.492 i" 2.1315 " 69.998, 1.554 " 2.220 " 70.000 Mean, 70.oo08, o.0019 Two more results, obtained by Rivott through the reduction of ferric oxide in hydrogen, remain to be noticed. The percentages are: 69.31 69.35 Mean, 69.33,.0oI3 We have thus before us six series of results, which we may now combine. * Compt. Rend., Oct. 17, I850. t Ann. Chem. Pharm., 78, 214. I85I. 134' THE ATOMIC WEIGHTS. Berzelius _-__- ___- ____-___ 70.020, -.0013 Erdmann and Marchand -_-_-_- 70.0094, 4-.0080 Svanberg and Norlin, Oxyd. 69.9534, 4-.0050 "d Reduc.___ 70.0354, *-.0055 Maumen6-_________ __.__ 70.0008, 4-.0019 Riveot__ ______ 69.33, --.013 General mean ____ 70.oo075, -4- ooIO From this we get Fe = 55.891, --.012; or, if O = 16, this becomes 56.0195. Dumas'* results, obtained from the chlorides of iron, are of so little weight that they might safely be omitted from our present discussion. For the sake of completeness, however, we will include them. Pure ferrous chloride, ignited in a stream of hydrochloric acid gas, was dissolved in water and titrated with a silver solution in the usual way. One hundred parts of silver are equivalent to the amounts of FeC12 given in the third column: 3.677 grmn. FeCi2 = 6.238 grm. Ag. 58.945 3.924 " = 6.675 " 58.787 Mean, 58.866, --.053 Ferric chloride, titrated in the same way, gave these results: 1.179 grm. Fe2C16 = 2-3475 grm. Ag. 50.224 1.242 " 2.471 50.263 Mean, 50.2435, ~ —.I032 These give us two additional values for Fe, as follows: From FeC2 ____ ____ Fe 56.028, 4-. I 9 " Fe2C16 _____ " _ 56. I89, -.062 Combining these with the value deduced from the composition of Fe2,03, Fe = 55.891, -.012, we get this general mean, Fe - 55.913, +-.012. If 0 = 16, this becomes Fe - 56.042. *Ann. Chem. Pharm., II3, 26. I860. COPPER. 135 COPPER. The atomic weight of copper has been chiefly determined from the composition of the black oxide and the anhydrous sulphate. In dealing with the first named compound all experimenters have agreed in reducing it with a current of hydrogen, and weighing the metal thus set free. The earliest experiments of any value were those of Berzelius,* whose results were as follows: 7.68075 grm. CuO lost 1.55 grm. 0. 79.820 per cent. Cu in CuO. 9.6115, 1 I-939 " 79.826 c. c Mean, 79.823, -.002 Erdmann and Marchand,t who come next in chronological order, corrected their results for weighing in air. Their weighings, thus corrected, give us the subjoined percentages of metal in CuO: 63.8962 grm. CuO gave 5I.039I grm. Cu. 79.878 per cent. 65.1590 52.0363 " 79.860 60.2878 " 48. 1540 " 79.874 46.2700 " d 36.9449 " 79.846 Mean, 79.8645, -.0038 Still later we find a few analyses by Millon and Commaille.t These chemists not only reduced the oxide by hydrogen, but they also weighed, in addition to the metallic copper, the water formed in the experiments. In three determinations the results were as follows: 6.7145 grm. CuO gave 5.3565 grin. Cu and 1.5325 grm. H20. 79.775 per cent. 3.3945 2.7085 ".7680 " 79.791 2.7880 " 2.2240 grm. Cu. 79-770 Mean, 79.7787, +-.0043 For the third of these analyses the water estimation was not made, but for the other two it yielded results which, in * Poggend. Annal., 8, 177. t Journ. fiir Prakt. Chem., 3I, 389. I844. 1 Fresenius' Zeitschrift, 2, 475. I863. 136 THE ATOMIC WEIGHTS. the mean, would make the atomic weight of copper 63.087, ~.222. This figure has so high a probable error that we need not consider it further. The results obtained by Dumas * are wholly unavailable. Indeed, he does not even publish them in detail. He merely says that he reduced copper oxide, and also effected the synthesis of the subsulphide, but without getting figures which were wholly concordant. He puts Cu = 63.5. Latest of all, and probably the best also, we have the determinations by Hampe.t First, he attempted to estimate the atomic weight of copper by the quantity of silver which the pure metal could precipitate ffom its solutions. This attempt failed to give satisfactory results, and he fell back upon the old method of reducing the oxide. From ten to twenty grammes of material were taken in each experiment, and the weights were reduced to a vacuum standard: 20.3260 grm. CuO gave I6.2279 grm. Cu. 79.838 per cent. 20.68851 " I6.51 669 " 79.835 IO. 10793 " 8.06926 " 79.831 Mean, 79.8347, -.0013 Hampe also determined the quantity of copper in the anhydrous sulphate, CuSO,. From 40 to 45 grammes of the salt were taken at a time, the metal was thrown down by electrolysis, and the weights were all corrected. I subjoin the results: 40.40300 grm. CuS04 gave I6.04958 grm. Cu. 39.724 per cent. 44.64280 cc 17.73466 " 39-726 " Mean, 39.725, 4-.0007 We now have four series of experiments upon copper oxide, as follows: Berzelius ____- _ __-___ 79.823, ~_.0020 Erdmann and Marchand __ __ 79.8645, --.0038 Millon and Commaille _ __ 79.7787,.0043 Hampe 79.8347, +.ooI3 General mean ___..-.__. 79.830, _.0010 *Ann. d. Chim. et Phys., (3,) 55, 129. t Fresenius' Zeitschrift, I3, 352. MOLYBDENUM. 137 For copper we haveFrom composition of CuO...Cu = 63. I8, -.o36 CUSO4, (Hampe) ___ " = 63. I7I, 4-.I2 General mean _______ " - 63.173, 4-.011 If 0 = 16, then Cu becomes - 63.318. The close agreement between the two independent values' for Cu is certainly very striking. It will be seen that Hampe's two estimates upon the sulphate carry (perhaps accidentally) much greater weight than all the experiments upon the oxide. This might seem like giving them undue credit, were it not for the fact of the remarkable concordance of the results above referred to. Either estimate for Cu would be valid without the other. MOLYBDENUM. If we leave out of account the inaccurate determination made by Berzelius,* we shall find that the data for the atomic weight of molybdenum lead to two independent estimates of its value; one near 92, the other near 96. The earlier results found by Berlin and by Svanberg and Struve lead to the lower number; the more recent work of Debray, Dumas, and Lothar Meyer sustains the higher. The latter value is the more probable, although both may be vitiated by constant errors in opposite directions. The earliest investigation which we need especially to consider is that of Svanberg and Struve.t These chemists tried a variety of different methods, but finally based their conclusions upon the two following: first, molybdenum trioxide was fused with potassium carbonate, and the carbon dioxide which was expelled was estimated; secondly, molybdenum disulphide was converted into the trioxide by K Poggend. Annal., 8, I. I826. r Journ. fur Prakt. Chem., 44, 301. I848. 138 rHE ATOMIC WEIGtHTS. roasting, and the ratio between the weights of the two substances was determined. By the first method it was found that 100 parts of MoO3 will expel the following quantities of C02: 31.4954 31.3749 31.4705 Mean, 31.4469, —.0248 The carbon dioxide was determined simply from the loss of weight when the weighed quantities of trioxide and carbonate were fused together. It is plain that if, under these circumstances, a little of the trioxide should be volatilized, the total loss of weight would be slightly increased.. A constant error of this kind would tend to bring out the atomic weight of molybdenum too low. By the second method, the conversion by roasting of MoS2 into MoO3, Svanberg and Struve obtained these results. Two samples of artificial disulphide were taken, A and B, and yielded for each hundred parts the following of trioxide: 89.7919 A 89729 I A. 89.6436 89.7082 89.7660 [B. 89.7640 89.8635 J Mean, 89.7523, --.0176 Three other experiments in series B gave divergent results, and, although published, are rejected by the authors themselves. Hence it is not necessary to cite them in this discussion. We again encounter in these figures the same source of constant error which apparently vitiates the preceding series, namely, the possible, volatilization of the trioxide. Here, also, such an error would tend to reduce the atomic weight of molybdenum. Upon discussing the data given in the foregoing para MOLYBDENUM. 139 graphs we get somewhat noticeable results. From the carbon dioxide series, Mo = 91.711, ~.113, a figure having no unusual interest. From the other series, if S = 31.987 and O - 15.9633, we get Mo = 92.979, -.354; but if we take S = 32 and O = 16, then Mo becomes - 92.133. In this case the higher values for oxygen and sulphur lead to a lower number for molybdenum. In the carbonate series the assumption of 12 and 16 for C and 0, respectively, makes Mo = 92.033. In other words, if we assume the ordinary even numbers for C, O, and S, Svanberg and Struve's two methods yield more nearly concordant results than when the revised values for these elements are taken. Berlin,* a little later than Svanberg and Struve, determined the atomic weight of molybdenum by igniting a molybdate of ammonium and weighing the residual MoO,. Here, again, a loss of the latter by volatilization may (and probably does) lead to too low a result. The salt used was (NH4)4Mo5001.3 H20, and in it these percentages of MoO, were found: 8.598 81.612 81.558 8I.555 Mean, 81.581, -4-.0095 Hence Mo = 91.9817, +.0776; a result agreeing quite well with those of Svanberg and Struve. Until 1859 the value 92 was generally accepted on the basis of the foregoing researches, but in this year Dumast published some figures tending to sustain a higher number. He prepared molybdenum trioxide by roasting the disulphide, and then reduced it to metal by ignition in hydrogen. At the beginning the hydrogen was allowed to act at a comparatively low temperature, in order to avoid volatilization of trioxide; but at the end of the operation the heat * Journ. fUr Prakt. Chem., 49, 444. i850. t Ann. Chem. Pharm., Io5, 84, and I 3, 23. 140 THE ATOMIC WEIGHTS. was raised sufficiently to insure a complete reduction. From the weighings I calculate the percentages of metal in MoO3:.448 grm. MoO3 gave.299 grm. Mo. 66.741 per cent..484 I" 323 " 66.736.484 ".322 " 66.529.498 cc.332 " 66.667 ~559 ".373 " 66.726.388 ".258 " 66.495 " Mean, 66.649, -.o030 In 1868 the same method was employed by Debray.* His trioxide was purified by sublimation in a platinum tube. His percentages are as follows: 5.514 grm. MoO3 gave 3.667 grm. Mo. 66.503 per cent. 7.9o0 " 5.265 t" 66.56I 9.031 6.oi5 " 66.604 Mean, 66.556, 4-.020 This mean, combined with that of Dumas', gives a general mean of 66.585, -.017. Hence Mo = 95.429, ~-.057. Debray also made two experiments upon the precipitation of molybdenum trioxide in ammoniacal solution by nitrate of silver. In his results, as published, there is curious discrepancy, which, I have no doubt, is due to typographical error. These results I am, therefore, compelled to leave out of consideration. They could not, however, exert a very profound influence upon the final discussion. The most recent investigation upon the atomic weight of molybdenum is the discussion by Lothar Meyer t of the experimental results obtained by Liechti and Kemp in their analyses of the chlorides. Of these compounds there are four: MoCl2, MoCl3, MoCl4, and MoC15. The chlorine in each was estimated as silver chloride, and the molybdenum as disulphide. From these analyses Meyer deduces three * Compt. Rend., 66, 734. t Ann. Chem. Pharm., I69, 365. I873. + Ann. Chem. Pharm., j69, 344. MOLYBDENUM. 141 sets of ratios, namely: between MoCln and n AgCl; between MoCln and MoS2, and between MoS2 and n AgC1. We will use only the first and last of these; the probable error of the atomic weight deduced from the second being relatively so high as to make the value connected with it comparatively unimportant. The analyses of the trichloride, being discordant, are here rejected. By reducing the weighings published by Liechti and Kemp* to a common standard we get the following percentage results. In MoCl2 the subjoined quantities of the original substance and of MoS2 correspond to 100 parts of AgCl: MoC12. MoS,. 58.299 55.762 58.194 55-59x 58.524 56.065 Mean, 58.339, 4-.o66 Mean, 55.806, -.o093 Hence MoCl2 = 166.902, --.188, and MoS2 = 159.652,:i.268. With the tetrachloride similarly calculated we get these figures, corresponding to 100 parts AgCl: MoC74. MoS,. 41.492 27.957 41.319 Mean, 41.4055, -.0583 Hence MoC14 = 236.914, -.358, and MoS2, if given the weight of a single experiment in the dichloride series, = 159.964, ~+-.627. * These are as follows:.2666 grm. MoC12 gave.2550 grm. MoS2 and.4573 grm. AgCl..8I 8i.1730.3112.2530 ".2422.4320.4126 grm. MoC14 gave.2780 ".9944.1923.4..4654 ".58Io grm. MoC15 gave.3414 " 1.5222.2466." I44I.6465 " 142 THE ATOMIC WEIGHTS. For the pentachloride the following quantities balance 100 of AgCl: MoCI5. IMroS2. 38.168 22.428 38.057 22.289 Mean, 38.112, -.038 Mean, 22.3585, 4-.040 Hence MoCl5 = 272.587, _+.271, and MoS2- 159.914, +.287. We have now the molecular weight of each chloride, and three values for that of the disulphide. Combining the latter we get a general mean, as follows: From MoC12 series _.____ MoS2 = 159.652, 4-.268 " MoC4.. = I59.964, 4-.627 " Mocl5 " 1. = i59.914, -.287 General mean_.___ " I59.790, -.187 With these data, in addition to those given by Dumas and by Debray, we get five estimates of the atomic weight of molybdenum: Dumas and Debray's data _____- _ __ Mo - 95.429, -.057 From molecular weight of MoCI,2 ______ " -= 96.262, +-.I90 MoC1l4_ " =95.434, 4-.363 MoCl5_-____" =95.737, -.28o.... i MoS _ " = 95.816, -.188 General mean ~_ _ ___ = 95.527, --.o05 Or, if 0 = 16, Mo = 95.747. It will at once be seen that the most reliable results are those obtained by the reduction of molybdenum trioxide. Traces of oxychlorides may possibly have contaminated the chlorides and augmented their atomic weight. Our final figure, therefore, may be a trifle too high, but the early value, 92, is unquestionably very far too low. Since the foregoing discussion was written a single experiment by Rammelsberg* has been brought to my notice. * Berlin Monatsbericht, I877, 574. TUNGSTEN. 1.43 Closely following Dumas' method, he reduced molybdenum trioxide to metal, finding in it 66.708 per cent. of the latter. This figure comes within the limits of variation of Dumas' experiments, and therefore gives them additional confirmation. Its introduction into the general mean, however, would exert too little influence upon the latter to justify the labor of recalculation. TUNGSTEN. The atomic weight of tungsten has been determined from analyses of the trioxide, the hexchloride, and the tungstates of iron, silver, and barium. The composition of the trioxide has been the subject of many investigations. Malaguti * reduced this substance to the blue oxide, and from the difference between the weights of the two compounds obtained a result now known to be considerably too high. In general, however, the method of investigation has been to reduce W03 to W in a stream of hydrogen at a white heat, and afterwards to reoxidize the metal, thus getting from one sample of material two results for the percentage of tungsten. This method is unquestionably accurate, provided that the trioxide used be pure. The first experiments which we need consider are, as usual, those of Berzelius.t 899 parts W03 gave, on reduction, 716 of metal. 676 of metal, reoxidized, gave 846 W03. Hence these percentages of W in W03: 79.644, by reduction. 79.905, by oxidation. Mean, 79.7745, 4-0880 These figures are far too high, the error being undoubtedly due to the presence of alkaline impurity in the trioxide employed. Journ. fiir Prakt. Chem., 8, 179. 1836. t- Poggend. Annal., 8, I. i826. 144 THE ATOMIC WEIGHTS. Next in order of time comes the work of Schneider,* who,, with characteristic carefulness, took every precaution to get pure material. His percentages of tungsten are as follows: Reduction Series. 79-336 79.254 79.312 79.326 79-350 Mean, 79.3I56, --.o0112 Oxidation Series. 79.329 79.324 79.328 Mean, 79.327, 4-.oo0010 Closely agreeing with these figures are those of Marchand,t published in the following year: Reduction Series. 79-307 79.302 Mean, 79.3045,.0017 Oxidation Series. 79.321 79-352 Mean, 79.3365, 4 —.005 The figures obtained by v. Borcht agree in mean tolerably well with the foregoing. They are as follows: Reduction Series. 79.310 79.212 79.289 79-313 79.225 79.290 79.302 Mean, 79.277, -4- oio6 Journ. fiir Prakt. Chem., 50, 152. 1850. t Ann. Chem. Pharm., 77, 26i. I851. IJourn. fiir Prakt. Chem., 54, 254. I85I. TUNGSTEN. 145 Oxidation Series. 79-359 79-339 Mean, 79.349, -_.0067 )ulnas gives only a reduction series, based upon trioxide obtained by the ignition of a pure ammonium tungsten. The reduction was effected in a porcelain boat, platinum being objectionable on account of the tendency of tungstate to alloy with it. Dumas publishes only weighings, from which I have calculated the percentages: 2.784 grm. W03 gave 2.208 grm. W. 79-3IO per cent. 2.994,, 2-373 " 79.259 4.600oo " 3.649 79-326.985 4".781 79.289.917,.727 79.280.917.728, 79-389 1.717' 1.362 " 79-324 2.988 2370 " 79-317 Mean, 79.312, ~.009 The data furnished by Bernoullit differ widely from those just given. This chemist undoubtedly worked with impure material, the trioxide having a greenish tinge. Hence the results are too high. These are the percentages of W: Reduction Series. 79.556 79.526 79-553 79-558 79-549 78.736.Mean, 79.413, —.09i Oxidation Series. 79-558 79.656 79-555 79.554 Mean, 79.58I, --.017 * Ann. Chem. Pharm., I 3, 23. I860. tPoggend. Annal., I I, 573. I860. 10 146 THE ATOMIC WEIGHTS. Two reduction experiments by Persoz * give the following results: 1.7999 grinm. WO3 gave 1.4274 grm. W. 79.304 per cent. 2.249 1. 784 " 79.324 Mean, 79.3I4, -.o007 Finally, we have the work done by Roscoe.-t This chemist used a porcelain boat and tube, and made six weighings, after successive reductions and oxidations, with the same sample of 7.884 grammes of trioxide. These weighings give me the following five percentages, which, for the sake of uniformity with foregoing series, I have classified under tile usual, separate headings: Reduction Series. 79. I96 79.285 79.308 Mean, 79.263, ~4.023 Oxidation Series. 79.230 79.299 AMean, 79.2645, -.0233 There are still other experiments by Riche,t which I have not been able to get in detail. They cannot be of any value, however, for they give to tungsten an atomic weight of about ten units too low. We may therefore neglect this series, and go on to combine the others: Berzelius____ _ ___- _ ___ 79-7745, 4-.o88 Schneider, Reduction. —----- 79.3156, -4-.OII2 " Oxidation - -. 79.327, 4-.00o Marchand, Reduction __ 79.3045, 4-.007 " Oxidation ---- ___- 79.3365, 4-.OI05 v. Borch, Reduction _____ _ 79.277, -.oio6 " Oxidation____ 79.349,.oo67 * Zeit. Anal. Chem., 3, 260. i864. -- Ann. Chem. Pharm., 162, 368. 1872. + Journ. fiir Prakt. Chem., 69, Io. i857. TUNGSTEN. 147 Dumas _-___ _ --- -- 79.312, 4-.009 Bernouilli, Reduction -_ —-— _ 79.413, -.09I " Oxidation - ___.___ 79.58I, -.017 Persoz ____ _______ —------- 79.314, 4-.007 Roscoe, Reduction__ - __ - 79.263, 4-.023 Oxidation - 79.2645, -.0233 General mean __-_____ 79.3215, -.ooo85 The rejection of the figures given by Berzelius and by Bernoulli exerts an unimportant influence upon the final result. There is, therefore, no practical objection to retaining them in the discussion. In 1861 Scheibler * deduced the atomic weight of tungsten from analyses of barium metatungstate, BaO. 4 WO 3.9 H20. In four experiments he estimated the barium as sulphate, getting closely concordant results, which were, however, very far too low. These, therefore, are rejected. But from the percentage of water in the salt a very good result was attained. The percentages of water are as follows: I3.053 I3.054 I3.045 I3.010 13.022 Mean, I3.o368, 4-.oo60 The work of Zettnow,t published in 1867, was somewhat more complicated than any of the foregoing researches. He prepared the pure tungstates of silver and of iron, and from their composition determined the atomic weight of tungsten. In the case of the iron salt the method of working was this: The pure, artificial FeWO4 was fused with sodium carbonate, the resulting sodium tungstate was extracted by water, and the thoroughly washed, residual ferric oxide was dissolved in hydrochloric acid. This solution was then reduced by zinc, and titrated for iron with potassium permanganate. Corrections were applied for the drop in excess of * Journ. fUr Prakt. Chem., 83, 324. t Poggend. Annal.. I30, 30. 148 THE ATOMIC WEIGHTS. permanganate needed to produce distinct reddening, and( for the iron contained in the zinc. 11.956 grammes of the latter metal contained iron corresponding to 0.6 cc. of the standard solution. The permanganate was standardized by comparison with pure ammonium-ferrous sulphate, Am2Fe(SO,)2. 6 1120, so that, in point of fact, Zettnow establishes directly only the ratio between that salt and the ferrous tungstate. From Zettnow's four experiments in standardizing I find that 1 cc. of his solution corresponds to 0.0365457 grammes of the double sulphate, with a probable error of ___.0000012. Three sets of titrations were made. In the first a quantity of ferrous tungstate was treated according to the process given above; the iron solution was diluted to 500 cc., and four titrations made upon 100 cc. at a time. The second set was like the first, except that three titrations were made with 100 cc. each, and a fourth upon 150 cc. In the third set the iron solution was diluted to 300 cc., and only two titrations upon 100 cc. each were made. In sets one and two thirty grammes of zinc were used for the reduction of each, while in number three but twenty grammes were taken. Zettnow's figures, as given by him, are quite complicated; therefore I have reduced them to a common standard. After applying all corrections the following quantities of tungstate, in grammles, correspond to 1 cc. of permanganate solution:.028301.02829I.028391 First set..02830I J.028367.0283681.028367. Second set..028367 J.028438 } Third set..o28438 Mean,.0283549, --.0000I 15 With the silver tungstate, Ag2 WO, Zettnow employed two methods. In two experiments the substance was de TUNGSTEN. 149 composed by nitric acid, and the silver thus taken into solution was titrated with standard sodium chloride. In three others the tungstate was treated directly with common salt, and the residual silver chloride collected and weighed. Here again, on account of some complexity in Zettnow's figures, 1 am compelled to reduce his data to a common standard. To 100 parts of AgCl the following quantities of Ag2 WO4 correspond: By First Aletghod. I61.665 i61. 603 Mean, 161.634, -+-.021 By Second Method. i61.687 I61.651 161.613 Mean, i61.650, -4-.014 General mean from both series, 161.645, ~.012 Finally, we have two analyses by Roscoe of tungsten hexchloride, published in the same paper with his results upon the trioxide. In one experiment the chlorine was determined as AgCl; in the other the chloride was reduced by hydrogen, and the residual tungsten estimated. By bringing both results into one form of expression we have for the percentage of chlorine in WC16: * 53.588 53.632 Mean, 53.6Io, 4-.015 We have now five ratios from which to calculate the atomic weight of tungsten: (I.) Percentage of W in W03, 79.3215, 4-.ooo85 (2.) Percentage of H20 in BaO.4W03.gH20, I3.0368, o.0o60 * The actual figures are as follows: I9.5700 grm. WC16 gave 42.4127 grmin. AgC1. 10.4326 " 4.8374 " tungsten. 150 THE ATOMIC WEIGHTS. (3.) Am2Fe(SO4)2.6H20: FeWO4::.0365457, 4-.ooooo0000012:.0283549, -.OOOOI 5 (4.) AgCl: Ag2WO4:: Ioo: I61.645, +.OI2 (5.) Percentage of C1 in WC16, 53.610, --.015 From these we get five values for tungsten, as follows: From (I) ____ W I83703, --.041 " (2)-_ _____-____ ___ " 1I83.532, -.I56 (3) —--------------- I83.923, --.120 " (4), -----------— __ " i83.248, 4.o69 "(5) —------ _________ " _ i83.639, -4-.109 General mean _.......' I83.6Io, -.032 Or, if O = I6, then" _ 184.032 URANIUM. It is not the purpose of the present investigation to examine at all systematically such questions as are involved in the discussion whether the atomic weight of uranium is 120 or 240. For convenience we may use the formulae based upon the smaller number, and, if eventually the larger'value proves to be correct, it will be easy to double the figures which we obtain. Suffice it to say here, that the specific heat of the green oxide, according to Donath,* agrees best with the formula U,30 and the lower atomic weight. On the other hand, the value 240 fits best into such schemes as that given by Mendelejeff in his paper on the periodic law. An accurate determination of the specific heat of the metal itself is much needed, for the material with which Regnault worked was of uncertain quality; furthermore, the vapor density of some volatile uranium compounds ought to be ascertained.t Until some such data have been rigidly * Ber. d. Deutsch. Chem. Gesell., 12, 742. I879. t The value of 240 for uranium is strongly sustained by the recent experiments of Zimmermann upon the vapor density of the tetrachlorid and tetrabromid. For UBr4 the vapor density is 19.46, while theory (U = 240) requires 19.36. For UC14 the v. d. 13.33 was found. Theory, 13.2I. (Ber. der Deutsch. Chem. Gesell., 14, s. I934. 88 I.) URANIUM. 151 established the controversy over the two rival values can hardly be satisfactorily settled. The earlier attempts to determine the atomic weight of uranium were all vitiated by the erroneous supposition that the uranous oxide was really the metal. The supposition, of course, does not affect the weighings and analytical data which were obtained, although these, from their discordance with each other and with later and better results, have now only a historical value. For present purposes the determinations made by Berzelius,* by Arfvedson,t and by Marchand,1 may be left quite out of account. Berzelius employed various methods, while the others relied upon estimating the percentage of oxygen lost upon the reduction of U304 to UO. Rammelsberg'sll results also, although very suggestive, need no full discussion. He analyzed the green chloride, UC12; effected thee synthesis of uranyl sulphate from uranous oxide; determined the amount of residue left upon the ignition of the sodio and bario-uranic acetates; estimated the quantity of magnesium uranate formed from a known weight of UO, and attempted also to fix the ratio between the green and the black oxides. His figures vary so widely that they could count for little in the establishing of any general mean; and, moreover, they lead to estimates of the atomic weight which are mostly below the true value. For instance, twelve lots of U304 from several different sources were reduced to UO by heating in hydrogen. The percentages of loss varied from 3.83 to 4.67, the mean being 4.121. These figures give values for the atomic weight of uranium ranging from 92.66 to 117.65, or, in mean, 107.50. Such discordance is due partly to impurity in some of the material studied, and illustrates the difficulties inherent in the problem to be solved. Some of the uranoso-uranic oxide was prepared by * Schweigg. Journ., 22, 336. I8I8. Poggend. Annal., I, 359. I825. t Poggend. Annal., I, 245. Berz. Jahr., 3, I20. I822. + Journ. fur Prakt. Chem., 23, 497. I841. I| Poggend. Annal., 55, 318, 1842; 56, I25, I842; 59, 9, I843; 66, 9I, 3845. Journ fiir Prakt. Chem., 29, 324. 15)<2 THE ATOMIC WEIGHTS. calcining the oxalate, and retained all admixture of carbonl. Many such points were worked up by Rammelsberg with much care, so that his papers should be scrupulously studied by any chemist who contemplates a redetermination of the atomic weight of uranium. In 1841 and 1842 Peligot published certain papers * showing that' the atomic weight of uranium must be somewhere near 120. A few years later the same chemist published fuller data concerning the constant in question, but in the time intervening between his earlier and his final researches other determinations were made by Ebelmen and by Wertheim. These investigations we may properly discuss in chronological order. For present purposes the early work of Peligot may be dismissed as only preliminary in character. It showed that what had been previously regarded as metallic uranium was in reality an oxide, but gave figures for the atomic weight of the metal which were merely approximations. Ebelmen's t determinations of the atomic weight of uranium were based upon analyses of uranic oxalate. This salt was dried at 100~, and then, in weighed amount, ignited in hydrogen. The residual uranous oxide was weighed, and in some cases converted into U3 0,, by heating in oxygen. The following weights are reduced to a vacuum standard: Io. 644 grm. oxalate gave 7.2939 grm. UO. 12.9985 " 9.3312 " Gain on oxidation,.3685 11.8007 " 8.4690o." 3275 9.9923 " 7.1 73I....2812 1.0887 " 7.9610 ".3105 10.0830 " 7.2389 6.7940 " 4.8766 i6.0594 11.5290 ".4 53I Reducing these figures to percentages, we may present the results in two columns. Column A gives the percentages of UO in the oxalate, while B represents the amount of U304 formed from 100 parts of UO: * Compt. Rend., 12, 735. I841. Ann. Chim. Phys., (3,) 55. I842. t Journ. fiir Prakt. Chem., 27, 385. I842. UR ANIUM. 153 A. B. 71.924 71.787 103.949 71.767 I03.867 7I.621 I03.920 71.794 I03.900 71.793 71.778 71.790 103.930 Mean, 71.782, 4-.019 Mean, 103.913, —.009 From column A, the molecular weight of UO = I34.523, 4-. 102 t" B, c "135.985, 4-.326 General mean_____ _ __ UO _ I34.652, --.097 From column A _ _.. U = 118.560' B ___ 120.022 From general mean of both columns _ = II8.689, ~.097 Wertheim's* experiments were even simpler in character than those of Ebelmen. Sodio-uranic acetate, carefully dried at 200~, was ignited, leaving the following percentages of sodium uranate: 67.5I508 67 54558 67.50927 Mean, 67.52331, -.0076 Hence the molecular weight of Na2U07 -- 634.865, +.191. And U = 119.282, +.048. The final results of Peligot's t investigations appeared in 1846. Both the oxalate and the acetate of uranium were studied and subjected to combustion analysis. The oxalate was scrupulously purified by repeated crystallizations, and thirteen analyses, representing different fractions, were made. Seven of these gave imperfect results, due to incomplete purification of the material; six only, from the later crystallizations, need to be considered. In these the uranium *Journ. fiir Prakt. Chem., 29, 209. I843. t Compt. Rend., 22, 487. 154 THE ATOMIC WEIGHTS. was weighed as U3 04, and the carbon as CO2. From the ratio between the CO2 and U 04 the atomic weight of uranium may be calculated without involving any error due to traces of moisture possibly present in the oxalate. I subjoin Peligot's weighings, and give, in the third column, the U304 proportional to 100 parts of CO,: CO2. U3 04. Ratio. 1.456 grm. 4.649 grmn. 319.299 1.369 " 4.412 " 322.279 2.209 " 7.084 " 320.688 I.OI9 " 3.279 " 321.786 I.O69 " 3.447 " 322.46I I.052 " 3.389 " 322.148 Mean, 321.443, — _.338 Hence U,3 0 423.342,:i.451. From the acetate, C2H3(UO)02.H20, the following percentages of U 0 4 were obtained: 5.06i grm. acetate gave 3.354 grm. U304. 66.27I5 per cent. 4..60oI 3.057 " 66.442I " I.869 " 1.238 " 66.2386 3.8I7 " 2.541 " 66.576 " Io. I82 " 6.757 66.3622 4.393 " 2.920 " 66.4694 2.868 " 1.897 66. 1437 Mean, 66.3569, 4-.o38 The acetate also yielded the subjoined percentages of carbon and of water. Assuming that the figures for carbon were calculated from known weights of dioxide, with C =- 12 and O 16, I have added a third column, in which the carbon percentages are converted into percentages of CO,: H20 C. co2. 21.60 11.27 41.323 21.16 11.30 41.433 2I. I0 11.30 41.433 21.20 I.I0 40.700 Mean, 21.265, 4-.187 11.24 41.222, 4-.092 URANIUM. 155 From all of these figures we may calculate the molecular weight of the uranic acetate as follows: From percentage of U304 -__ C2H,(UO)02.H20 = 212.629, -.242 CO2 " - 2I2.999, -.476 " H20.____ " = 2 I1. 184, -- I.863 General mean _ _ " = 212.685, +-.214 We have now before us the molecular weights of four uranium compounds, giving us four values for U: (I.) UO = 134.652, 4-.og97 —. —........Ebelmen. (2.) Na2U407 = 634.865, 4.1i9-i ___. Wertheim. (3.) U304 = 423.342, 4-.45I _.____Peligot. (4.) C2H3(UO)02.H20 - = 212.685, +-.214 - " The four values for uranium combine as follows: From (I) -iU = I 8.689, -.097 Ebelmen. (2)_ _ "=II9.282, +-.048 Wertheim. (3) "= I I9.830, 4-.150 Peligot. (4) -. —- _ —____" —- II9.885, --.215 General mean__......." —- I119.24I, ~_.041 Or, if 0 = 16, U = 119.515, or 239.030. Considering Peligot's figures by themselves, and combining values 3 and 4, we have U 119.849, +.123; or, if O = 16, U = 120.125, or 240.250. It is plain that the atomic weight of uranium needs to be scrupulously revised. The foregoing figures are by no means satisfactory. Chemically considered, it is probable that Peligot's work is the best, and that his results should be given preference. His figures from the oxalate and the acetate tally well with each other, whereas Ebelmen's two sets of results vary widely. From the percentage of UO yielded by the oxalate, Ebelmen's figures give a low value for U. From his oxidation of UO to U304 we get a value nearly two units higher. Peligot, in his work with the oxalate, found it, even after three or four crystallizations, to be contaminated with oxalic acid, and rejected the figures obtained from impure material. Probably Ebelmen's low values are due to the same impurity. 156 THE ATOMIC WEIGHTS. ALUMINUM. The atomic weight of aluminum has been determined by Berzelius, Mather, Tissier, Dumas, Isnard, Terreil, and Mallet. The early calculations of Davy and of Thomson we may properly disregard. Berzelius' * determination rests upon a single experiment. He ignited 10 grammes of dry aluminum sulphate, A12(SO,)3, and obtained 2.9934 grammes of A1, 03 as residue. Hence, if S = 31.987 and O 15.9633, Al - 27.243. In 1835 t Mather published a single analysis of aluminum chloride, from which he sought to fix the atomic weight of the metal. 0.646 grm. of A12C16 gave him 2.056 of AgC1 and 0.2975 of A1203. These figures give worthless values for Al, and are included here only for the sake of completeness. From the ratio between AgC1 and Al2C16, Al = 28.925. Tissier's I determination, also resting on a singlb experiment, appeared in 1858. Metallic aluminum, containing.135 per cent. of sodium, was dissolved in hydrochloric acid. The solution was evaporated with nitric acid to expel all chlorine, and the residue was strongly ignited until only alumina remained. 1.935 grin. of Al gave 3.645 grin of A1203. If we correct for the trace of sodium in the aluminum, we have Al = 27.073. Essentially the same method of determination was adopted.by Isnard,l[ who, although not next in chronological order, may fittingly be mentioned here. He found that 9 grin. of aluminum gave 27 grin. of A1203. Hence Al = 26.938. In 1858 Dumas,~ in connection with his celebrated revision of the atomic weights, made seven experiments with aluminum chloride. The material was prepared in quantity, *Poggend. Annal., 8, I77. tf Silliman's Amer. Journ., 27, 241. $ Compt. Rend., 46, 10o5. I Comnpt. Rend., 66, 508. I868. Ann. Chim. Phys., (3,) 55, 15I. Ann. Chem. Pharm., I13, 26. ALUMINtUM. 157 sublimed over iron filings, and finally resublimed from metallic aluminum. Each sample used was collected in a small glass tube, after sublimation from aluminum in a a stream of dry hydrogen, and hermetically enclosed. Having been weighed in the tube, it was dissolved in water, and the quantity of silver necessary for precipitating the chlorine was determined. Reducing to a common standard, his weighings give the quantities of Al2C16 stated in the third column, as proportional to 100 parts of silver: I.8786 grm. A12C16 = 4.543 grm. Ag. 41.352 3.02I " 7.292 41.459-Bad. 2.399 5.802 4.348 1.922 " 4.6525'. 4I.311 1.697 4.1015 " 41.375 4.3165 " IO.448 41.314 6.728," i6.265 cc 41-365 In the second experiment the Al2Cl6 contained traces of iron. Rejecting this experiment the remaining six give a mean of 41.344, -.007. Hence Al = 27.441, +.082. In consequence of these figures of Dumas, the atomic weight of aluminum has generally of late years been put at 27.5, and the lower results deduced from the work of other investigators have been disregarded. In 1879 Terreil* published a new determination of the atomic weight under consideration, based upon a direct comparison of the metal with hydrogen. Metallic aluminum, contained in a tube of hard glass, was heated strongly in a current of dry hydrochloric acid. Hydrogen was set free, and was collected over a strong solution of caustic potash. 0.410 grm. of aluminum thus were found equivalent to 508.2 cc., or.0455 grm. of hydrogen. Hence Al = 27.033. About a year after Terreil's determination appeared the lower value for aluminum was thoroughly confirmed by J. W. Mallet.t After giving a full resume of the work done by others, exclusive of Isnard, the author describes his own experiments, which may be summarized as follows: * Bulletin de la Soc. Chimique, 31, I53. t Phil. Trans., I88O, p. I003. 158 THE ATOMIC WEIGHTS. Four methods of determination were employed, each one simple and direct, and at the same time independent of the others. First, pure ammonia alum was calcined, and the residue of aluminum oxide was estimated. Second, aluminum bromide was titrated with a standard solution of silver. Third, metallic aluminum was attacked by caustic soda, and the hydrogen evolved was measured. Fourth, hydrogen was set free by aluminum, and weighed as water. Every weight was carefully verified, the verification being based upon the direct comparison, by J. E. Hilgard, of a kilogramme weight with the standard kilogramme at Washington. The specific gravity of each piece was determined, and also of all materials and vessels used in the weighings. During each weighing both barometer and thermometer were observed, so that every result represents a real weight in vacuo. The ammonium alum used in the first series of experiments was specially prepared, and was absolutely free from ascertainable impurities. The salt was found, however, to lose traces of water at ordinary temperatures; a circumstance which tended towards a slight elevation of the apparent atomic weight of aluminum as calculated from the weighings. Two sets of experiments were made with the alum; one upon a sample air-dried for two hours at 21~-25~, the other upon material dried for twenty-four hours at 19~-26~. These sets, marked A and B respectively, differ slightly; B being the less trustworthy of the two, judged from a chemical standpoint. Mathematically it is the better of the two. Calcination was effected with a great variety of precautions, concerning which the original memoir must be consulted. To Mallet's weighings I append the percentages of Al1 03 deduced from them: Series A. 8.2144 grm. of the alum gave.9258 grm. A1,03. 11.270 per cent. I4.0378 c 1.5825 " 11.273 " 5.620I ".6337 " 11.275 11.2227 " 1.2657 " 11.278 " 10.8435 1.2216 " 11.266 " Mean, 11.2724, --.00I4 ALUMINUM. 159 Series B. I2.I023 grin. of the alum gave 1.3660 grm. A1203. II.287 per cent. I0.4544 c I. 1796 " 11.283 6.7962 ".7670 " 11.286 8.5601oi.9654 " 11.278 4.8992 " 5528 " 11.283 Mean, 11.2834, 4-.OOI I Combined, these series give a general mean of 11.2793, i.0008. Hence Al - 27.075, +.011. The aluminum bromide used in the second series of experiments was prepared by the direct action of bromine upon the metal. The product was repeatedly distilled, the earlier portions of each distillate being rejected, until a constant boiling point of 263.03 at 747 mm. pressure was noted. The last distillation was effected in an atmosphere of pure nitrogen, in order to avoid the possible formation of oxide or oxy-bromide of aluminum; and the distillate was collected in three portions, which proved to be sensibly identical. The individual samples of bromide were collected in thin glass tubes, which were hermetically sealed after nearly filling. For the titration pure silver was prepared, and after fusion upon charcoal it was heated in a Sprengel vacuum in order to eliminate occluded gases. This silver was dissolved in specially purified nitric acid, the latter but very slightly in excess. The aluminum bromide, weighed in the sealed tube, was dissolved in water, precautions being taken to avoid any loss by splashing or fuming which might result from the violence of the action. To the solution thus obtained the silver solution was added, the silver being something less than a decigramme in deficiency. The remaining amount of silver needed to complete the precipitation of the bromine was added from a burette, in the form of a standard solution containing one milligramme of metal to each cubic centimetre. The final results were as follows, the figures in the third column representing the quantities of bromide proportional to 100 parts of silver. Series A is from the first portion of the last distillate of A12Br6; series 160 THE ATOMIC WEIGHTS. B from the second portion, and series C from the third portion: Series A. 6.0024 grm. Al2Br6 =- 7.2793 grm. Ag. 82.458 8.6492 " I0.4897 " 82.454 3. I808, 3.8573 " 82.462 Series B. 6.9617, 8.4429 " 82.456 1.2041 o" 13.5897 " 82.445 3.762I " 4.5624 " 82.459 5.2842 " 6.4085 " 82.456 9.7338 I II.8047 " 82.457 Series C. 9.3515,, II.3424 82.447 4.4426 " 5-3877 " 82.458 5.2750 " 6.3975 i' 82.454 Mean, 82.455, - -.o00 Hence Al - 27.046, ~.061. The high probable error of this result is due to the high probable error of the atomic weight of bromine. The experiments to determine the amount of hydrogen evolved by the action of caustic soda upon metallic aluminum were conducted with pure metal, specially prepared, and with caustic soda made from sodium. The soda solution was so strong as to scarcely lose a perceptible amount of water by the passage through it of a dry gas at ordinary temperature. As the details of the experiments are somewhat complex, the original memoir must be consulted for them. The following results were obtained, the weight of the hydrogen being calculated from the volume, by Regnault's data corrected for the latitude and elevation of the University of Virginia: Weight of Al. Vol. of H. Wt. of H. At. [ft..3697 grm. 458.8 c. c..04106 grm. 27.012.3769 " 467.9.04I87 " 27.005.3620 " 449. I ".0409 " 27.022.7579 94I.5 ".08425 " 26.998.7314 " 907.9.08125 " 27.006.7541 936.4.08380 " 26.996 Mlean, 27.005, 0.0032 ALUMINUM. 161 The closing series of experiments was made with larger quantities of aluminum than were used in the foregoing set. The hydrogen, evolved by the action of the caustic alkali, was dried by passing it through two drying tubes containing pumice stone and sulphuric acid, and two others containing asbestos and phosphorus pentoxide. Thence it passed through a combustion tube containing copper oxide heated to redness. A stream of dry nitrogen was employed to sweep the last traces of hydrogen into the combustion tube, and dry air was afterwards passed through the entire apparatus to reoxidize the surface of reduced copper, and to prevent the retention of occluded hydrogen. The water formed by the oxidation of the hydrogen was collected in three drying tubes. The results obtained were as follows. The third column gives the amount of water formed from 10 grammes of aluminum: 2.1704 grm. Al gave 2.1661 grm. H20. 9.9802 2.9355 " 2.9292 " 9.9785 5.2632 " 5.2562 " 9.9867 Mean, 9.9818, I-.ooI7 Hence Al = 26.998, +.007. In combining the various determinations of the atomic weight of aluminum into one general mean, we must arbitrarily assign weight to the single experiments of Berzelius, Isnard, Tissier, and Terreil. This may fairly be done by giving to each the probable error, and therefore the weight, of a single observation in Dumas' series. Maather's work may be ignored altogether: From Berzelius _. ___.__Al A 27.243, ~.20I " Tissier-____ _.__.__ " -27.096, ~.201 i" Ifnard- ____ -_____" -26.938, -.201 " Dumas " - 27.44I, ~.082 Terreil ___________ " = 27.033, ~.201 Mallet's alum experiments," - 27.075, ~-.0 II A12Br6 ". ". 27.046, -.o6I.. H. " " = 27.005, --.003.. H20 ".. = 26.998, -0-.o07 General mean _ __ " — 27.0092,.00oo28 11 162 T'I E ATOMIC WEIGHTS. If O - 16, A1 - 27.075. Taking Mallet's work alone, Al 27.0089, -.0028. Evidently all the data except Mallet's might be rejected without affecting sensibly the final result. Dumas' work is clearly vitiated by constant errors, but the determinations by Isnard, Tissier, and Terreil may be regarded as having some confirmative value. GOLD. The only determinations of the atomic weight of gold which are worthy of consideration are those of Berzelius and of Levol. The earliest method adopted by Berzelius* was that of precipitating a solution of gold chloride by means of a weighed quantity of metallic mercury. The weight of gold thus thrown down gave the ratio between the atomic weights of the two metals. In the single experiment which Berzelius publishes, 142.9 parts of Hg precipitated 93.55 of Au. Hence, using the value for mercury given in a preceding chapter, 199.712, Au - 196.113. In a later investigations Berzelius resorted to the analysis of potassio-auric chloride, 2KCl.AuCl,. Weighed quantities of this salt were ignited in hydrogen; the resulting gold and potassium chloride were separated by means of water, and both were collected and estimated. The loss of weight upon ignition was, of course, chlorine. As the salt could not be perfectly dried without loss of chlorine, the atomic weight under investigation must be determined by the ratio between the KCl and the Au. If we reduce to a comnmon standard, and compare with 100 parts of KC1, the equivalent amounts of gold will be those which I give inll the last of the subjoined columns: Poggend. Annal., 8, 177. t Lehrbuch, 5 Aufl., 3, I212. GOLD 163 4.I445 grm. I2AuC15 gave.8185 gnn. KC1 and 2.159 grm. Au. 263.775 2.2495.44425 " 1.172 " 263.815 5.1300 I.01375 " 2.67225 263.600 3.4130 ".674 " 1.77725 " 263.687 4. I9975 ".8295 " 2. 88 " 263.773 Mean, 263.730, -.026 Hence Au - 196.186, -.101. Still a third series of experiments by Berzelius * may be included here. In order to establish the atomic weight of phosphorus he employed that substance to precipitate gold from a solution of gold chloride in excess. Between the weight of phosphorus taken and the weight of gold obtained it was easy to fix a ratio. Since the atomic weight of phosphorus has been better established by other methods, we may properly reverse this ratio and apply it to our discussion of gold. 100 parts of P precipitate the quantities of Au given in the third column:.829 grm. P precipitated 8.714 grm. Au. I05o.I5.754 " 7.930 " 1051.73 Mean, IO5I.44, -_-.I96 Hence Au - 195.303, -_+.589. Levol's t estimation of the atomic weight under consideration can hardly have much value. A weighed quantity of gold was converted in a flask into AuCl3. This was reduced by a stream of sulphur dioxide, and the resulting sulphuric acid was determined as BaSO4. One gramme of gold gave 1.782 grm. BaSO4. Hence Au = 195.794. If we give this single experiment and Berzelius' single result with mercury each equal weight with one analysis in the potassio-auric chloride series, and include respectively the probable errors appertaining to Hg and to BaSO4, we may combine all the data as follows: *Lehrbuch, 5 Aufl., 3, I 88. t Ann. d. Chim. et d. Phys., (3,) 30, 355. I850. 164 THE ATOMIC WEIGHTS. From KCI: Au ratio...-.Au -- I96.186, ~-.IOI From Hg: Au ratio_. "- - I96. II3, 4-.335 From P: Au ratio..__' =- I95.303, -.589 From BaSO4: Au ratio__... " — I95794, 1.234 General mean ___ "- - 196.155, -0.095 Or, if O = 16, Au = 196.606. As gold is a metal which can be readily applied to the determination of the atomic weights of other elements, an experimental revision of its atomic weight is very desirable. NICKEL AND COBALT. On account of the close similarity of these metals to each other, their atomic weights, approximately if not actually identical, have received of late years much attention. The first determinations, and the only ones up to 1852, were made by Rothhoff; * each with but a single experiment. For nickel 188 parts of the monoxide were dissolved in hydrochloric acid; the solution was evaporated to dryness, the residue was dissolved in water, and precipitated by silver nitrate. 718.2 parts of silver chloride were thus formed; whence Ni = 58.925. The same process was applied also to cobalt, 269.2 parts of the oxide being found equivalent to 1029.9 of AgCl. Hence Co = 58.817. These values are so nearly equal that their differences were naturally ascribable to experimental errors. They are, however, entitled to no special weight at present, since it cannot be certain from any evidence recorded that the oxide of either metal was absolutely free from traces of the other. In 1852 Erdmann and Marchandt published some results, but without details, concerning the atomic weight of nickel. They reduced the oxide by heating in a current of * Cited by Berzelius. Poggend. Annal., 8, I84. I826. tJourn. fiir Prakt. Chem., 55, 202. 1852. NICKEL AND COBALT. 165 hydrogen, and obtained values ranging from 58.2 to 58.6, when O = 16. Their results were not very concordant, and the lowest was probably the best. In 1856, incidentally to other work, Deville* found that 100 parts of pure metallic nickel yielded 262 of sulphate; whence Ni - 59.15. To none of the foregoing estimations can any importance now be attached. The modern discussion of the atomic weights under consideration began with the researches of Schneidert in 1857. This chemist examined the oxalates of both metals, determining carbon by the combustion of the salts with copper oxide in a stream of dry air. The carbon dioxide thus formed was collected as usual in a potash bulb, which, in weighing, was counterpoised by a similar bulb, so as to eliminate errors due to the hygroscopic character of the glass. The metal in each oxalate was estimated, first by ignition in a stream of dry air, followed by intense heating in hydrogen. Pure nickel or cobalt was left behind in good condition for weighing. Four analyses of each oxalate were made, with the results given below. The nickel salt contained three molecules of water, anc the cobalt salt two molecules: NiC2 o4.32 -O. I.1945 gnnrm. gave.528 grm. CO2. 44.203 per cent. 2.5555 " 1.12625 " 44.072 " 3. I99 1.408 44.0I4 5.020 " 2.214 44. 104 " Mean, 44.098, 4-.027 The following percentages of nickel were found in this salt: 29.107 29.082 29.o66 29.082 Mean, 29.084, -.0- oo6 * Ann. Chim. Phys., (3,) 46, 182. I856. t Poggend. Annal., IOI, 387. x857. 166 THE ATONIIC WEIGHTS. (oC2 04. 2z 2 0. 1.6355 grm. gave.78I grm. CO2. 47-7.53 per cent. 1.107 ".5295 47.832 2.309 " I. IOI 47.683 3.007 " 1.435 " 47.722 Mean, 47.7475,.o0213 The following were the percentages found for cobalt: 32.552 32.619 32.528 32.523 Mean, 32.5555, -.OI49 In a later paper* Schneider also gives some results obtained with a nickel oxalate containing but two molecules of water. This gave him 47.605 per cent. of CO2, and the following percentages of nickel: 31.4 15 3 1 4038 Mean, 31.4076, ~.0026 The conclusion at which Schneider arrived was, that the atomic weights of cobalt and nickel are not identical, being about 60 and 58 respectively. The percentages given above will be discussed at the end of this chapter in connection with all the other data relative to the constants in question. The next chemist to take up the discussion of these atomic weights was Marignac, in 1857.t His original paper is not accessible to me, and I am therefore obliged to give only such features of it as I can get from abstracts and reviews. He worked with the chlorides and sulphates of nickel and cobalt, using apparently common gravimetric methods. The sulphates, taken as anhydrous, were first ignited to expel SO2-+ 0, after which the residues were heated with weighed amounts of lead silicate. The increase in weight * Poggend. Annal., 107, 6i6. t Jahresberidht, 1857, 225. Bibl. Univ. de Geneve, (nouv. s.,) I, 373. NICKEL AND COBALT. 167 was CoO or NiO respectively. The anhydrous chlorides were prepared from the hydrated salts by ignition in dry chlorine or hydrochloric acid. With cobalt, the monohydrated chloride, dried at 100~, was also employed. For nickel he gives the following values, referred probably to O 16, S - 32. Ag= 108, C1 = 35.5: From NiSO4 __-__ _ Ni = 58.4 to 59.o,, NiCI2,,__ 58.4 " 59.28 To cobalt these values are assigned: From CoSO4.-__ ____ ____Co = 58.64 to 58.76 CoC12.H20 _,, 58.84 " 59.o02 CoCC12 -,,_ —- ------ __ 58.72 " 59.02 That is, contrary to Schneider's view, the two atomic weights are approximately the same. The values for nickel, however, run a little lower than those for cobalt; a fact which is probably not without significance. Marignac criticizes Schneider's earlier paper, holding that the nickel oxalate may have contained some free oxalic acid, and that the cobalt salt was possibly contaminated with carbonate or with basic compounds. In his later papers Schneider rejects these suggestions as unfounded, and in turn criticizes Marignac. The purity of anhydrous NiSO4 is not easy to guarantee, and, according to Schneider, the anhydrous chlorides of cobalt and nickel are liable to be contaminated with oxides. This is the case even when the chlorides are heated in chlorine, unless the gas is carefully freed from all traces of air and moisture. Dumas' * determinations of the two atomic weights were made with the chlorides of nickel and cobalt. The pure metals were dissolved in aqua regia, the solutions were repeatedly evaporated to dryness, and the residual chlorides were ignited in dry hydrochloric acid gas. The last two estimations in the nickel series were made upon NiCI2 formed by heating the spongy metal in pure chlorine. In the third column I give the NiCl2 or CoCl2, equivalent to 100 parts of silver: *Ann. Chem. Pharm., 113, 25. I86o. 1 68 THE ATOMIC WEIGHTS..9123 grm. NiCl2 I1.515 grin. Ag. 60.2I8 2.295 3.8I115 " 60.212 3.290 " 5.464 " 60.212 1.830 " 3.04i 60. 178 3.00I 1 4.987 " 60. 176 Mean, 60. I1992, 4-.0062 2.352 grm. CoC12 39035 grin. Ag. 60.254 4.2IO " 6.990 " 60.229 3.592 5.960 " 60.268 2.492 4. I405 " 6o. I86 4.2295 " 7.0255' 60.202 Mean, 60.2278, --.OI I These results give values for Co and Ni differing by less than a tenth of a unit; here, as elsewhere, the figure for Ni being a trifle the lower. In 1863 * the idea that nickel and cobalt have equal atomic weights was strengthened by the researches of Russell. He found that the black oxide of cobalt, by intense heating in an atmosphere of carbon dioxide, became converted into a brown monoxide of constant composition. The ordinary oxide of nickel, on the other hand, was shown to be convertible into a definite monoxide by simple heating over the blast lamp. The pure oxides of the two metals, thus obtained, were reduced by ignition in hydrogen, and their exact composition thus ascertained. Several samples of each oxide were taken, yielding the following percentages of metal: V 0. 78.597' 78.584 3 ISt sample. 78.608 78.581 78.589 2d sample. 78.583 78.6I6 ) 78.590 }-3d sample. 78.588 78.590 1 78.594 p 4th sample. 78.597 78.588 J Mean of all, 78.593, --.ooi8 * Journ. Chem. Soc., (2,) I, 51. NICKEL AND COBALT. 169 CoO. 78-59I ] 78.588 78-550 Ist sample. 78-598 78.614 J 78.603 } 78.591 2d sample. 78-59I' 78592 }3d sample. 78-597 78.598 4th sample. 78. 595 } 78.589 5th sample. 78.596 Mean of all, 78.592, 4-.0023 These percentages are practically identical, and lead to essentially the same mean value for each atomic weight. In a later paper Russell* confirmed the foregoing results by a different process. He dissolved metallic nickel and cobalt in hydrochloric acid and measured the hydrogen evolved. Thus the ratio between the metal and the. ultimate standard was fixed without the intervention of any other element. About two-tenths of a gramme of metal, or less, was taken in each experiment. 100 parts by weight of Co or Ni give the following weights of H, calculated from the volume of the latter: Ni'. Co. 3.420 3395 3-4 i8 |3-398 1 st sam3ple. 3.4I6 3-3978 3.417 ) ist sample. 3-398 J 3.412 3.403 } 3.4I5 3.401 2d sample. 3.4I6 j 3.401 ) *Journ. Chem. Sec., (2,) 7, 494. I869. 170 THE ATOMIC WEIGHTS. Ai. Co. 3.398 3.404 3d sample. 3.409 2d sample. 3405 3same. 3.404 3.4IO 3.407 3410 4th sample. 3.412 - 3.4o8 4th sample. Mean of all, 3.4017, --.0009 3.4Io Mean of all, 3.411, -.00I A glance at the tabulated discussion which closes this chapter will show that these figures agree well with each other, and well with those found from the analyses of the oxides. The probable errors assigned in the hydrogen series may be a little too low, since they ought to be modified by the probable error of the weight of a unit volume of hydrogen. So insignificant a correction may, however, be neglected. Some time after the publication of Russell's first paper, but before the appearance of his second, some other investigations were made known. Of these the first was by Sommaruga,* whose results, obtained by novel methods, closely confirmed those of Schneider and antagonized those of Dumas, Marignac, and Russell. The atomic weight of nickel Sommaruga deduced from analyses of the nickel potassium sulphate, K2Ni(SO4),.6H,O, which, dried at 1000, has a perfectly definite composition. In this salt the sulphuric acid was determined in the usual way as barium sulphate, a process to which there are obvious objections. In the third column are given the quantities of the nickel salt proportional to 100 parts of BaSO4: 0.9798 grm. gave.o0462 grm. BaSO4. 93.653 I-0537 t I.125i,, 93.654 I.0802 " 1.1I535 " 93.645 i. I865,, I.2669,, 93.654 3.2100 " 3-4277,, 93.649 3.2124 " 3.4303 " 93.648 Mean, 93.6505, --.oo1 * Sitzungsb. Wien Akad., 54, 2 Abth., 50. i866. NICKEL AND COBALT. 171 For cobalt Sommaruga used the purpureo cobalt chloride of Gibbs and Genth. This salt, dried at 1100, is anhydrous and stable. Heated hotter, CoC12 remains. The latter, ignited in hydrogen, yields metallic cobalt. In every experiment the preliminary heating must be carried on cautiously until ammoniacal fumes no longer appear:.6656 grin. gave.1588 grm. Co. 23.858 per cent. 1.0918 ".2600 " 23.814.9058.2160 " 23.846 1.5895 3785 " 23.813 2.9I67 6957 23.847 1.8390 " 4378 23.806 2.50IO " 5968 " 23.808 Mean, 23.827, -.oo6 Further along this series will be combined with a similar one by Lee. It may here be said that Sommaruga's paper was quickly followed by a critical essay from Schneider,* endorsing the former's work, and objecting to the results of Russell. In 1867 still another new process for the estimation of these atomic weights was put forward by Winkler,t who determined the amount of gold which pure metallic nickel and cobalt could precipitate from a neutral solution of sodioauric chloride. Experimentally, the method seems to be quite accurate; practically, it involves a knowledge of the defectively ascertained atomic weight of gold. In order to obtain pure cobalt Winkler prepared purpureo-cobalt chloride, which, having been four or five times recrystallized, was ignited in hydrogen. His nickel was repeatedly purified by precipitation with sodium hypochlorite. From material thus obtained pure nickel chloride was prepared, which, after sublimation in dry chlorine, was also reduced by hydrogen. 100 parts of gold are precipitated by the quantities of nickel and cobalt given in the third columns respectively. In the cobalt series I include one experiment * Poggend. Annal., I30, 31 0. t Zeit. Anal. Chem., 6, I8. I867. 172 THE ATOMIC WEIGHTS. by Weselsky which was published by him in a paper presently to be cited:.4360 grm. nickel precipitated.9648 grm. gold. 45.191.4367,,.9666 " 45.-79.5189. I1I457 "'45.291.6002 " 1.3286 " 45.175 Mean, 45.209, -4-.019.5890 grm. cobalt precipitated 1.3045 grm. gold. 45.I51.3147.698 " 45.080.5829,, I.29I3 " 45. 4I.5111 " I.1312 45.182.5821 1.2848 " 45.307 *559 " 1.241 " 45.044-Weselsky. Mean, 45.I5I, -4-.025 Weselsky's paper,* already cited, relates only to cobalt. He ignited the cobalticyanides of ammonium and of phenylammonium in hydrogen, and from the determinations of cobalt thus made deduced its atomic weight. His results are as follows:.7575 grmin. (NH4)6Co2Cy12 gave.I66 grm. Co. 21.9I4 per cent..5143.113 " 21.972 " Mean, 21.943, -.029.8529 grm. (C6H8N)6Co2Cyx2 gave.IOIO gril. Co. II.842 per cent..6112 ".0723 " I1I.829 " ~7I40 c.0850 " II.905.9420 ".II20 " I1.890 " Mean, I I.8665, --.0124 Finally, we come to the work done by Leet in the laboratory of Wolcott Gibbs. Like Weselsky, Lee ignited certain cobalticyanides and nickelocyanides in hydrogen and determined the residual metal. The double cyanides chosen were those of strychnia and brucia; salts of very high molecular weight, in which the percentages of metal are relatively low. A series of experiments with purpureo-cobalt Ber. d. Deutsch. Chem. Gesell., 2, 592. I868.' Am. Journ. Sci. and Arts, (3,) 2, 44. 187I. NICKEL AND COBALT. 173 chloride was also carried out. In order to avoid admixture of carbon in the metallic residues, the salts were first ignited in air, and then in oxygen. Reduction by hydrogen followed. The salts were in each case covered by a porous septum of earthenware, through which the hydrogen diffused, and which served to prevent the mechanical carrying away of solid particles; furthermore, heat was applied from above. The results attained were very satisfactory, and assign to nickel and cobalt atomic weights varying from each other by about a unit; Ni being nearly 58, and Co about 59. The exact figures will appear later. The cobalt results agree remarkably well with those of Weselsky. The following are the percentages of metal found: In brucia nickelocyanide, Ni3Cy12( C23H26,V 04)6H'6. zoH20. 5.724 5.729 5.750 5.733 5.712 5.729 Mean, 5.7295, 4- 0034 In strychnia nickelocyanide, N4i3Cy2,( C21H22N2 02)6. H6.8H2 0. 6.607 6.613 6.589 6.607 6.56i 6.595 Mean, 6.595, 4-.005 In brucia cobalticyanide, Co2Cy12( C23H26N 04)6.H6.o20,2 0. 3.759 3.720 3.739 3.748 3-747 3-749 Mean, 3.7437, 4-.0036 174 THE ATOMIC WEIGHTS. In str:ychnia cobalticyanide, Co2 Cyl2( C211,22V', 2). ) H6.8 12 0. 4.583 4.596 4.554 4.564 4.577 4.549 Mean, 4.5705, 4-.005 In purpureo-cobalt chloride, Co2(N2Vr3)l0C16. 23.575 23- 587 23.586 23- 579 23.569 23.581 Mean, 23.5795, 4-.0019 The last series may be combined with Sommaruga's, thus: Sommaruga 23.827, -.0oo6 Lee _____..- _____ ___ —-— 23.5795, -+-.0019 General mean _ 23.6045, ~_+.ooi8 In discussing the atomic weights of nickel and cobalt, we may ignore the work of Rothhoff, Erdmann and Marchand and Deville. That of Marignac must also be omitted, for' want of sufficient data. For nickel we have the following ratios. The probable error assigned in No. 4, is that of a single experiment in No. 2: (I.) Per cent. of Ni in NiC204.3H20, 29.084, -.oo6 (2.) " CO2 from " 44.098, -4-.027 (3.) " Ni in NiC20. 2H20, 31.4076, 4-.0026 (4.) CO2 from c; 47.605, -.053 (5-) " Ni in NiO, 78.593, ~-.ooi8 (6.)... brucia nickelocyanide, 5.7295, -4-.0034 (7.).. strychnia " 6.595, 4.005 (8.) Ag: NiCl2:: oo: 6o. I992, 4-.0062 (9.) Ni: H:: Ioo: 3.4I I, -.o00 (Io.) Au: Ni:: I00: 45.209, ~-.019 (II.) BaSO4: K2Ni(SO4)2.6H20:: 1oo: 93.6505, 4-..ooI Since the proportion of water in the oxalates is not an absolutely certain quantity, the data concerning such salts NICKEL AND COBALT. 175 are best handled by employing the ratios between the carbon dioxide and the metal. Accordingly ratios (1) and (2) give a single value for Ni, and ratios (3) and (4) another. In all, we have nine values for the atomic weight in question: From (I) and (2) ___- _Ni- 57.907, _.o0379 (3)" (4) — 57-926,.0o654 (6)-_ __ = 57.884, -.0396 " (7) " = 57-947, --.0467 " (II) —____ -__________ " = 58. I70, o.o829 " (5) " - 58.607, - -.OI39 (9) - ---- - = 58.634, ~-.i065 " (8)_ __ __ 58.899, -4-.0339 10(IO)-________ " 59. I20, 4-.0376 General mean __,, " = 58.547, 4-.0089 If O = 16, Ni = 58.682. In the foregoing result it will be seen that the two sets of figures due to Russell receive very great weight. This is because the one set is referred directly to hydrogen, without the intervention of the probable error of any other element; while the second set involves only the atomic weight of oxygen, of which the probable error is small. As regards accuracy of methods, however, and certainty concerning the purity of material, Russell's work is no better than Schneider's, and probably inferior to Lee's. Now values one to five in the above table represent the tolerably concordant results of Schneider, Lee, and Sommaruga. They, combined by themselves, give a general mean of Ni = 57.928, +-.0215; or, if O - 16, of Ni = 58.062. This value, taking everything into account, I cannot but regard as more likely to prove correct than the larger mean deduced from all the ratios. At all events, the atomic weight of nickel needs further careful investigation. For cobalt these ratios are available: (I.) Per cent. of Co in CoC204.2H20, 32.5555, 4-.OI49 (2.) " C02 from " 47-7475, --.02I3 (3-) " Co in CoO, 78.592, +-.0023 (4.) cc purpureo-cobalt chloride, 23.6045, 4-.ooi8 (5.) c; phenylammonium cobalticyanide, 11.8665, -.0124 (6.) c " ammonium " 21.943, -4-.029 176 THE ATOMIC WEIGHTS. (7.) Per cent. of Co in brucia cobalticyanide, 3.7437, -.0036 (8.) " " strychnia " 4.5705, 4-.005 (9.) Ag: CoC12:: Ioo: 60.2278, -4-.I I (Io.) Co: H:: Ioo 3.4017, -.oo0009 (II.) Au: Co:: IO: 45.I5I, 4-.025 Hence we have ten values for Co, as follows: From (I) and (2) Co_____CO 59.865, --.0394 (4) —- " = 59.080, -.0152 " (5) — - " = 58.913, ~.0628 " (6)._. _ _ ___ --- 59. I77, -.o816 " (7), _ —- _ = 59.057, -.0581 " (8)- "-__ 58.960, 4-.0708 "' (iI)___________- -____ " = 59.044, +.0436 - - (9) - _____ _ " - 58.96I, +-.0392 (3),, - 58.604, -4-.0145 (IO)_- " -58.794, +-.oi62 General mean -____ - 58.887, +.o08 If - = 16, Co = 59.023. SELENIUM. The atomic weight of this element was first determined by Berzelius,* who, saturating 100 parts of selenium with chlorine, found that 179 of chloride were produced. Further on these figures will be combined with similar results by Dumas. ~We may omit, as unimportant for present purposes, the analyses of alkaline selenates made by Mitscherlich and Nitzsch,t and pass on to the experiments published by Sacc e in 1847. This chemist resorted to a variety of methods, some of which gave good results, while others were unsatisfactory. First, he sought to establish the exact composition of SeO2, both by synthesis and by analysis. The former plan, according to which he oxidized pure selenium by * Poggend. Annal., 8, I. 1826. i Poggend. Annal., 9, 623. I827. Ann. d. Chim. et d. Phys., (3,) 2I, II9. SELENIUM. 177 nitric acid, gave poor results; better figures were obtained upon reducing SeO, with ammonium bisulphite and hydrochloric acid, and determining the percentage of selenium set free:.68oo grm. SeO, gave.4828 grm. Se. 71.ooo per cent. 3.5227 " 2.5047 " 7. 102 4.4870 " 3 I930 71.I6I " Mean, 71.o088, -.032 In a similar manner Sacc also reduced barium selenite, and weighed the resulting mixture of barium sulphate and free selenium. This process gave discordant results, and a better method was found in calcining BaSeO, with sulphuric acid, and estimating the resulting quantity of BaSO4. In the third column I give the amounts of BaSO, equivalent to 100 of BaSeO3:.5573 grm. BaSeO3 gave.4929 grm. BaSO4. 88.444 ~9942 ".8797 " 88.383.2351 ".2080 " 88.473.9747 ".8621 " 88.448 Mean, 88.437, --.0OI3 Still other experiments were made with the selenites of silver and lead; but the figures were subject to such errors that they need no further discussion here. A few years after Sacc's work was published, Erdmann and Marchand made with their usual care a series of experiments upon the atomic weight under consideration.* They alalyzed pure mercuric selenide, which had been repeatedly sublimed and was well crystallized. Their method of manipulation has already been described in the chapter upon mercury. These percentages of Hg in HgSe were found: 71.726 71.731 7 1.74I Mean, 71.7327, 4-.003 * Journ. fur Prakt. Chem., 55, 202. I852. 12 178 THIE ATOMIC WEIGHTS. The next determinations were made by Dumas,* who returned to the original method of Berzelius. Pure selenium was converted by dry chlorine into SeCl4, and from the gain in weight the ratio between Se and C1 was easily deducible. I include Berzelius' single experiment, which I have already cited, and give in a third column the quantity of chlorine absorbed by 100 parts of selenium: 1.709 grm. Se absorb 3.o049 gnn. C1. I78.409 i.8io " 3.219 " 177.845 i.679 3-003 " I78.856 1.498 " 2.688 1 I79.439 1.944 " 3.468 " 178-395 1.887 " 3.382 " I79.226 I1935 3.452 " I78.398 I 79.000ooo-Berzelius. Mean, 178.696, --.125 The question may here be properly asked, whether it would be possible thus to form SeCl4 and be certain of its absolute purity? A trace of oxychloride, if simultaneously formed, would increase the apparent atomic weight of selenium. In point of fact, this method gives a higher value for Se than any of the other processes which have been adopted, and that value has the largest probable error of any one in the entire series. A glance at the table which summarizes the discussion at the end of this chapter will render this point sufficiently clear. Latest of all, we come to the determinations made by Ekman and Pettersson.* They tried various methods of investigation, and finally decided upon the two following: First. Pure silver selenite, Ag2SeO3 was ignited, leaving behind metallic silver in the subjoined percentages: *Ann. Chem. Pharm., II3, 32. i86o. t Ber. d. Deutsch. Chem. Gesell., 9, 12Io. I876. Published in detail by the society at Upsala. SELENIUM. 179 62.93 62.95 62.97 62.94 62.98 62.98 62.95 Mean, 62.957, -4-.005 Second. A warm aqueous solution of selenious acid was mixed with HC1, and reduced by a current of SO2. The reduced Se was collected upon a glass filter, dried, and weighed. Percentages of Se in SeO2: 71. I99 7I. I85 71. 93 71. 87 7I.I9I Mean, 7.1I9, -+.ooI6 This series, combined with that of Sacc, 71.088, -.032, gives a general mean of 71.1907, ~.0016. There are now five series of figures from which to deduce the atomic weight of selenium: (I.) Per cent. of Se in SeO,, 7I.I907, 4-.ooi6 (2.) BaSeOa: BaSO4:: IOO: 88.437, 4-.013 (3.) Per cent. of Hg in HgSe, 71.7327, +.003 (4.) Se: SeCl4:: IOO: I78.696, --.125 (5.) Per cent. of Ag in Ag2SeO., 62.957, 4-.005 From these we get the following values for selenium: From (I) -Se = 78.894, 4-.o8 " (2>)... " —-.. _ = 78.362, --.053 " (3) --------------- " 78.700, 4-.0I9 " (4) —---- --— _____ 79. 74, 4-.o64 " (5) —--— = —_______ " _ 78.8I9, -.025 General mean _ —__ - 78-797, +-.o01 If O = 16, Se = 78.978. 180 THE ATOMIC WEIGHTS. TELLURIUM. Particular interest attaches to the atomic weight of tellurium, on account of the speculations of Mendelejeff. According to the "periodic law" of that chemist, tellurium should lie between antimony and iodine, having an atomic weight greater than 120, and less than 127. Theoretically, Mendelejeff assigns it a value of Te- 125; but all the published determinations lead to a mean number higher than would be admissible under the aforesaid "periodic law." Whether theory or experiment is at fault remains to be discovered. The first, and for many years the only, determinations of the constant in question, were made by Berzelius.* By means of nitric acid he oxidized tellurium to the dioxide, and from the increase in weight deduced a value for the metal. He published only his final results; from which, if O = 100, Te = 802.121. The three separate experiments give Te = 801.74, 801.786, and 802.838;'whence we call calculate the following percentages of metal in the dioxide: 80.o57 80.o36 80.o034 Mean, 80.042, —.005 The next determinations were made by von Hauer,t who resorted to the analysis of the well crystallized double salt TeBr4.2KIBr. In this compound the bromine was estimated as silver bromide, the values assumed for Ag and Br being respectively 108.1, and 80. Recalculating, with our newer atomic weights for the above named elements, we get from v. Hauer's analyses, for 100 parts of the salt, the quantities of AgBr which are put in the third column: * Poggend. Annal., 28, 395. I833. t Sitzungsb. Wien Akad., 25, 142. TELLURIUM. 181 2.000 grin. K2TeBr6 gave 69.946 per cent. Br. 164.460 6.668 " 69.8443 " I64.22I 2.934 69.9 13 " I64.379 3.697 " 70.0163 " 164.626 I.000 " 69.901 go " 164.355 Mean, I64.408, -.045 From Berzelius' series we may calculate Te = 128.045, and from v. Hauer's Te -- 127.419. Dumas,* by a-method for which he gives absolutely no particulars, found Te = 129. In 1879, with direct reference to Mendelejeff's speculations, the subject of the atomic weight of tellurium was taken up by Wills.t The methods of both Berzelius and von Hauer were employed, with various rigid precautions in the way of testing balance and weights, and to ensure purity of material. In the first series of experiments tellurium was oxidized by nitric acid to form TeO2. The results gave figures ranging from Te = 126.31 to 129.34: 2.21613 grm. Te gave 2.77612 grm. TeO2. 79.828 per cent. Te. 1.45313 4" 1.81542 " 80.044 " 2.67093 " 3-33838 " 80.007 " 4.77828 " 5.95748 " 80.207 " 2.65029 " 3.31331 " 79.989 " Mean, 80.0o5, ---.041 In the second series tellurium was oxidized by aqua regia to TeO2; with results varying from Te = 127.77 to 128.00: 2.85011 grin. Te gave 3.56158 grm. TeO2. 80.024 per cent. Te. 3.09673 " 3.86897 " 80.040 5.o09365 6.36612 A" 80.012 " 3.26604 " 4.08064 " 80.037 " Mean, 80.028, -~-.004 Combining these series with that due to Berzelius, we have the following general mean: *Ann. d. Chim. et d. Phys., (3,) 55, I29. I859. t Journ. Chem. Society, Oct., 1879, p. 704. 182 THE ATOMIC WEIGHTS. Berzelius-..-... _____ _____80.042, 4-.005 Wills, Ist series ~-...._- 8o.oi5, -i-.041 2d " -_ __ 80.028,-4-.004 General mean_ 80.035, --.003 Hence Te - 127.986, +.035. By von Hauer's process, the analysis of TeBr4.2KIBr, Will's figures give results ranging from Te = -126.07 to 127.61. Reduced to a common standard, 100 parts of the salt yield the quantities of AgBr given in the third column: I. 70673 grmn. K2TeBr6 gave 2.80499 grm. AgBr. 164.349 1.75225 " 2.88072 " 164.398 2.06938 " 3.40739 " I64.657 3.29794 " 5.43228 " I64.7I7 2.46545 it 4.05742 " 164.571 Mean, I64.538, ~.048 Combined with von Hauer's mean, 164.408, +.045, this gives a general mean of 164.468, +-.033. Hence Te127.170, ~+-.173. The two independent values for Te combine thus: From TeO2 _, —.... ____.Te - 127.986, -.035 TeKBr6 _, __ I27- 70, --.173 General mean ____. " -- 127.960, -=.034 If 0 = 16, Te = 128.254. A careful consideration of the foregoing figures, and of the experimental methods by which they were obtained, will show that they are not absolutely conclusive with regard to the place of tellurium under the periodic law. The atomic weight of iodine, calculated in a previous chapter, is 126.557. Wills' values for Te, rejecting his first series as relatively unimportant, range from 126.07 to 128.00; that is, some of them fall below the atomic weight of iodine, although none descend quite to the 125 assumed by Mendelejeff. In considering the experimental methods, reference may properly be made to the controversy regarding the atomic weight of antimony. It will be seen that Dexter, estimating the latter constant by the conversion of the metal VANADIUM. 183 into Sb204, obtained a value approximately of Sb = 122. Dumas, working with SbCl3, obtained a similar value. Schneider and Cooke, on the other hand, have established an atomic weight for antimony near 120, and Cooke in particular has traced out the constant errors which lurked unsuspected in the work of Dumas and Dexter. Now in some physical respects tellurium and antimony are quite similar. As constant errors vitiated the recently accepted values for Sb, so they may also effect our estimates for Te. The oxidation of Te by nitric acid resembles in minor particulars that of Sb. The analysis of K2TeBr6, gives a low value for Te, and yet the material may have contained traces of oxybromides, the presence of which would render even that lower value too high. A careful revision of the atomic weight of tellurium is still necessary. VANADIUM. Roscoe's determination of the atomic weight of vanadium is the only one having any present value. The results obtained by Berzelius * and by Czudnowicz t are unquestionably too high; the error being probably due to the presence of phosphoric acid in the vanadic acid employed. This particular impurity, as Roscoe has shown, prevents the complete reduction of V2 05 to V2 03 by means of hydrogen. All vanadium ores contain small quantities of phosphorus, which can only be detected with ammonium molybdate; a reaction unknown in Berzelius' time. Furthermore, the complete purification of vanadic acid from all traces of phosphoric acid is a matter of great difficulty, and probably never was accomplished until Roscoe undertook his researches. In his determination of the atomic weight, RoscoeS * Poggend. Annal., 22, 14. I83I. t Poggend. Annal., I20, I7. I863.: Journ. Chem. Soc., 6, pp. 33o and 344. I868. 184 THE ATOMIC WEIGHTS. studied two compounds of vanadium; namely, the pentoxide, VO, and the oxychloride, VOCl3. The pentoxide, absolutely pure, was reduced to V,,03 by heating in hydrogen, with the following results: 7.7397 grm. V205 gave 6.3827 grm. V203. I7.533 per cent. of loss. 6.58I9 " 5.4296 " 17-507 5.1895 4.28I9 " I7-489 5.0450 4 I614 " I7.515 " 5.4296 grm. V20s, reoxidized, gave 6. 5814 grm. V205. 17. 50l per cent. difference. Mean, I7.509, ~.0o05 Hence AV = 51.264, ~.025. Upon the oxychloride, VOC13, two series of experiments were made, one volumetric, the other gravimetric. In the volumetric series the compound was titrated with solutions containing known weights of silver, which had been purified according to the methods recommended by Stas. Roscoe publishes his weighings, and gives percentages deduced from them; his figures, reduced to a common standard, make the quantities of VOCl3 given in the third column proportional to 100 parts of silver. He was assisted by two analysts: Analyst A. 2.4322 grm. VOC1A = 4.5525 grin. Ag. 53-425 4.6840 8.7505 " 53.528 4.2188 " 7.8807 " 53.533 3-9490 7.3799 " 53-5I1.9243 1.7267 " 53-530 1.4330 2.6769 " 53-532 Analyst B. 2.8530 " 5.2853 " 53.980 2. I252 " 3.9535 " 53-755 1.4248 " 2.6642 " 53-479 Mean, 53.586, +-.039 The gravimetric series, of course, fixes the ratio between VOC13 and AgC1. If we put the latter at 100 parts, the proportion of VOC13 comes out as given in the third column: ARSENIC. 185 Analyst A. 1.8521 gnrn. VOC13 gave 4.5932 grm. AgC1. 40.323.70I3, I1.7303 c 40o.53I.7486 1.8467 " 40-537 1.4408 " 3.5719 40.337 -9453 " 2.3399 " 40.399 I.6I83 " 4.0282 " 40. 74 Analyst B. 2. I936' 5.4039 " 40-391 2.5054 " 6.2II8 " 40.333 Mean, 40.378, 4-.028 These two series give us two values for the molecular weight of VOC1,: From the volumetric series ___VOCl3 = 73.096, 4-.126 " gravlmetric " ___ " 1 73.276, 4-.141 General mean.... " -1 73. I77, --.094 Hence V - 51.104, 4.104. Combining the two values for AV we get the following result: From V20 ____V 51.264, 4-.025 " VbOC1a ____"___ -_ — s 5.104, -- Io04 General mean-5.- - -- 51.256, ~-.024 Or, if 0 = 16, V = 51.373. ARSENIC. For the determination of the atomic weight of arsenic two compounds have been studied; the chloride and the trioxide. The bromide may also be considered, since it was analyzed by Wallace in order to establish the atomic weight of bromine. His series, in the light of more recent knowledge, may properly be inverted, and applied to the determination of arsenic. In 1826, Berzelius * heated arsenic trioxide with sulphur * Poggend. Annal., 8, I. 186 THE ATOMIC WEIGHTTS. in such a way that only SO2 could escape. 2.203 grammes of As2 03, thus treated, gave a loss of 1.069 of SO2. Hence As = 74.840. This is a close estimation; but, being drawn from a single experiment, has so little weight that it need not be included in our final general mean. In 1845 Pelouze* applied his method of titration with known quantities of pure silver to the analysis of the trichloride of arsenic, AsCl3. Using the old Berzelian atomic weights, and putting Ag = 1349.01, and Cl = 443.2, he found in three experiments for As the values 937.9, 937.1, and 937.4. Hence 100 parts of silver balance the following quantities of AsCl3: 56.029 56.009 56.016 Mean, 56.0oi, +.004 Later, the same method was employed by I)umas,t whose weighings, reduced to the foregoing standard, give the following results:, 4.298 grm. AsC13 = 7.673 grm. Ag. Ratio, 56.0I5 5.535 " 9.880 " 56.022 7.660 I13.686 " 55-970 4.680 " 8.358 " 55-993 Mean, 56.ooo,.0oo8 The two series of Pelouze and Dumas, combined, give a general mean of 56.014, ~.0035, as the amount of AsC13 equivalent to 100 parts of silver. Hence As = 74.829, -+-.048, a value closely agreeing with that deduced from the single experiment of Berzelius. The same process of titration with silver was applied by Wallacet to the analysis of arsenic tribromide, AsBr3. This compound was repeatedly distilled to ensure purity, and was well crystallized. His weighings show that the quanti* Compt. Rend., 20, 1047. t Ann. Chim. Phys., (3,) 55, 174. 1859. I Philosophical Magazine, (4,) I8, 279. ARSENIC. 187 ties of bromide given in the third column are proportional to 100 parts of silver: 8.3246 grm. AsBr3 = 8.58 grm. Ag. 97.023 4.4368 " 4.573 " 97.022 5.o098 " 5.257 " 96.970 Mean, 97.005, 4-.012 Hence As = 74.046, +.058. Why this value should be so much lower than that from the chloride is unexplained. The volumetric work done by Kessler,* for the purpose of establishing the atomic weights of chromium and of arsenic, has already been described in the chromium chapter. In that investigation the amount of potassium dichromate required to oxidize 100 parts of As203 to As,O, was determined, and compared with the quantity of potassium chlorate necessary to produce the same effect. From the molecular weight of KC103, that of K2Cr207 was then calculable. From the same figures, the molecular weights of KC103 and of KCr207 being both known, that of As2,03 may be easily determined. The quantities of the other compounds proportional to 100 parts of As203 are as follows: K2 Cr2 0,. KC/03. 98.95 41.156 98.94 41.116 99. 7 41.200 98.98 41.255 99.o8 41.201 99. I 5 4I.086 4II99 Mean, 99.045, 4-.0o2 41.224 41.I6I 4I1I93 41. 49 41. 26 Mean, 41.172, -.009 * Poggond. Annal., 95, 204. 1855. Also I13, I34. i86I. 188 THIE ATOMIC WEIGHTS. Another series with the bichromate gave the following figures: 99.08 99.o6 99.o10 98.97 98.97 Mean, 99.o036, -.o0g Mean of previous series, 99.o045, 4-.028 General mean, 99.039, --.oi6 Other defective series are given to illustrate the partial oxidation of the As,O3 by action of air. The foregoing figures give us two distinct values for the molecular weight of As2,03. In calculating from the bichromate results the value for chromium deduced from Siewert's determinations will be used, viz., Cr = 52.009, +-.025. From KC103 series-.As203 = 197.996, 4-.049 " K2Cr207 - I97.777, 4-.05I General mean.. " = I97.894, ~-.035 Hence As = 75.002, +.018. The general mean for As comes out as follows: From AsCsl3- __ ___ ___As = 74.829, 4-.048 " AsBr3 " = 74.046, 4-.058 As203, = 75.002, 4-.oi8 General mean. —--- " = 74.918, --.oi6 If 0 - 16, then As becomes - 75.090. ANTIMONY. After some earlier, unsatisfactory -determinations, Berzelius,* in 1826, published his final estimation of the atomic weight of antimony. He oxidized the metal by means of nitric acid, and found that 100 parts of antimony gave 124.8 of Sb204. Hence, if O = 16, Sb =- 129.03. The * Poggend. Annal., 8, i ANTIMONY. 189 value 129 remained in general acceptance until 1855, when Kessler,* by special volumetric methods, showed that it was certainly much too high. Kessler's results will be considered more fully further along, in connection with a later paper; for present purposes a brief statement of his earlier conclusions will suffice. Antimony, and various compounds of antimony, were oxidized partly by potassium anhydrochromate and partly by potassium chlorate; and from the amounts of oxidizing agent required, the atomic weight in question was deduced: By oxidation of Sb203 from Ioo parts of Sb _ —..___Sb = I23.84 it Sb with K2Cr207__ " = 123.6.... KC103 + K2Cr207.___. " I123-72 t" Sb,20 with " _ _.. — - i23.80 Sb2S3 with K2Cr20_____ __ " 23.58 t" tartaremetic ___ ___ " =II9.80 The figures given are those calculated by Kessler himself. A recalculation with our newer atomic weights for 0, K, Cl, Cr, S, and C, would yield slightly lower values. It will be seen that five of the estimates agree closely, while one diverges widely from the others. It will be shown hereafter that the concordant values are all vitiated by constant errors, and that the exceptional figure is after all the best. Shortly after the appearance of Kessler's first paper, Schneidert published some results obtained by the reduction of antimony sulphide in hydrogen. The material chosen was a very pure stibnite from Arnsberg, of which the gangue was only quartz. This was corrected for, and corrections were also applied for traces of undecomposed sulphide carried off mechanically by the gas stream, and for traces of sulphur retained by the reduced antimony. The latter sulphur was estimated as barium sulphate. From 3.2 to 10.6 grammes of material were taken in each experiment. The final corrected percentages of S in Sb2S3 were as follows: * Poggend. Annal., 95, 215. t Poggend. Annal., 98, 293. 1856. Preliminary note in Bd. 97. 190 THE ATOMIC WEIGHTS. 28.559 28.557 28.501 28.554 28.532 28.485 28.492 28.48I Mean, 28.520, 4-.oo8 Hence, if S = 32, Sb = 120.3. Immediately after the appearance of Schneider's memoir, Rose * published the result of a single analysis of antimony trichloride, previously made under his supervision by Weber. This analysis, if C1 = 35.5, makes Sb = 120.7, a value of no great weight, but in a measure confirmatory of that obtained by Schneider. The next research upon the atomic weight of antimony was that of Dexter,t published in 1857. This chemist, having tried to determine the amount of gold precipitable by a known weight of antimony, and having obtained discordant results, finally resorted to the original method of Berzelius. Antimony, purified with extreme care, was oxidized by nitric acid, and the gain in weight was determined. From 1.5 to 3.3 grammes of metal were used in each experimcnt. The reduction of the weights to a vacuum standard was neglected as being superfluous. From the data obtained, we get the following percentages of Sb in Sb204: 79.268 79.272 79.255 79.266 79.253 79.27I 79.264 79.260 79.286 * Poggend. Annal., 98, 455. I856. t Poggend. Annal., IOO, 563. ANTIMONY. 191 79.274 79.232 79-395 79.379 Mean, 79.283, -.009 Hence, if O - 16, Sb = 122.46. The determinations of Dumas * were pnblished in 1859. This chemist sought to fix the ratio between silver and antimonious chloride, and obtained results for the atomic weight of antimony quite near to those of Dexter. The SbCl1 was prepared by the action of dry chlorine upon pure antimony; it was distilled several times over antimony powder, and it seemed to be perfectly pure. Known weights of this preparation were added to solutions of tartaric acid in water, and the silver chloride was precipitated without previous removal of the antimony. Here, as Cooke has since shown, is a possible source of error, for under such circumstances the crystalline argento-antimonious tartrate may also be thrown down and contaminate the chloride of silver. But be that as it may; Dumas' weighings, reduced to a common standard, give as proportional to 100 parts of silver, the quantities of SbC13 which are stated in the third of the subjoined columns: 1.876 grm. SbCI 3 2.660 grm. Ag. 70.526 4.336 - 6.148 " 70.527 5.065 " 7. I75 70.592 3.475 " 4.930 70.487 3.767 " 5.350 " 70.4I 5.9o 10 8.393 70.416 4.828 " 6.836 " 70.626 Mean, 70.512, 4-.021 Hence, if Ag 108, and C1 = 355, Sb = 122. In 1861 Kessler's second papert relative to the atomic weight of antimony appeared. Kessler's methods were somewhat complicated, and for full details the original memoirs must be consulted. A standard solution of potassium anhydrochromate was prepared, containing 6.1466 *Ann. Chim. Phys., (3,) 55, 175. f~ Poggend. Annal., II3, I45. 192 THE ATOMIC WEIGHTS. grammes to the litre. With this, solutions containing known quantities of antimony or of antimony compounds were titrated, the end reaction being adjusted with a standard solution of ferrous chloride. In some cases the titration was preceded by the addition of a definite weight of potassium chlorate, insufficient for complete oxidation; the anhydrochromate then served to finish the reaction. The object in view was to determine the amount of oxidizing agent, and therefore of oxygen, necessary for the conversion of known quantities of antimonious into antimonie compounds. In the later paper Kessler refers to his earlier work, and shows that the values then found for antimony were all too high, except in the case of the series made with tartar emetic. That series he merely states, and subsequently ignores, evidently believing it to be unworthy of further consideration. For the remaining series he points out the sources of error. These need not be rediscussed here, as the discussion would have no value for present purposes; suffice it to say that in the series representing the oxidation of Sb203 with anhydrochromate and chlorate, the material used was found to be impure. Upon estimating the impurity and correcting for it, the earlier value of Sb =- 123.80 becomes Sb = 122.36, according to Kessler's calculations. In the paper now under consideration four series of results are given. The first represents experiments made upon a pure antimony trioxide which had been sublimed, and which consisted of shining colorless needles. This was dissolved, together with some potassium chlorate, in hydrochloric acid, and titrated with anhydrochromate solution. Six experiments were made, but Kessler rejects the first and second as untrustworthy. The data for the others are as follows: Sb2 03. KClO,. K2 Cr207 sol. in cc. 1.7888 grm..4527 grm. 19.2 CC. 1.6523 ".4506 " 3.9 3.2998 ".8806 " I6.5 I.3438 ".3492 " I0.2" From. these figures Kessler deduces Sb = 122.16. ANTIMONY. 193 These data, reduced to a common standard, give the following quantities of oxygen needed to oxidize 100 parts of Sb 23 to SbO, 5. Each cubic centimetre of the KCrO 7 solution corresponds to one milligramme of 0: Io.985 10.939 0. 95I 10.936 Mean, 10.953, +_.0075 In the second series of experiments pure antimony was dissolved in hydrochloric acid with the aid of an unweighed quantity of potassium chlorate. The solution, containing both antimonious and antimonic compounds, was then reduced entirely to the antimonious condition by means of stannous chloride. The excess of the latter was corrected with a strong hydrochloric acid solution of mercuric chloride, then, after diluting and filtering, a weighed quantity of potassium chlorate was added, and the titration with anhydrochromate was performed as usual. Calculated as above, the percentages of oxygen given in the last column correspond to 100 parts of antimony: Sb. KCO,. K,2Cr2,7 sol. cc. Per cent. 0. 1.636 grni. 0.5000 grin. 18.3 I3.088 3.0825 0.9500 " 30.2 I3.050 4.5652" 1.4I06 " 45.5 I3.098 MIean, I3.079, ~__.0096 This series gave Kessler Sb - 122.34. The third and fourth series of experiments were made with pure antimony trichloride, SbC13, prepared by the action of mercuric chloride upon metallic antimony. This preparation, in the third series, was dissolved in hydrochloric acid, and titrated. In one experiment solid K2Cr207 in weighed amount was added before titration: in the other two estimations KC103 was taken as usual. If, according to Siewert's work, we take Cr = 52.009, the percentages of oxygen in the last column correspond to 100 parts of SbCl3: 13 194 THE ATOMIC WEIGHTS..Per cent. 0. 1.8576 grm. SbC13 needed.5967 grinm. K2Cr207 and 33.4 cc. sol. 7.0338 x.9118 ".3019 " KC103 " I6.2 " 7.0321 4.1235 ".680I " ". 23.2 " 7.0222 Mean, 7.0294, +-.0024 The fourth set of experiments was gravimetric. The solution of SbC13, mixed with tartaric acid, was first precipitated by hydrogen sulphide, in order to remove the antimony. The excess of H2S was corrected by copper sulphate, and then the chlorine was estimated as silver chloride in the ordinary manner. 100 parts of AgCl correspond to the amounts of SbC13 given in the third column. 1.8662 grm. SbC13 gave 3.483 grm. AgC1. 53.580 1.6832 it 3.141 " 53.588 2.7437 5.1115 " 53.677 2.6798 " 5.0025,, 53.569 5.047 " 9.41I " 53.629 3.8975 " 7.2585 " 53.696 Mean, 53.623, +-.OI$ The volumetric series with SbCl3 gave Kessler values for Sb ranging from 121.16 to 121.47. The gravimretric series, on the other hand, yielded results from Sb = 124.12 to 124.67. This discrepancy Kessler rightly attributes to the presence of oxygen in the chloride; and, ingeniously correcting for this error, he deduces from both sets combined, the value of Sb - 122.37. The several mean results for antimony agree so fairly with each other, and with the estimates obtained by Dexter and Dumas, that we cannot wonder that Kessler felt satisfied of their general correctness, and of the inaccuracy of the figures published by Schneider. Still, the old series of data obtained by the titration of tartar emetic with anhydrochromate contained no evident errors, and was not accounted for. This series,* if we reduce all of Kessler's figures to a single common standard, give a ratio between KICr207 and C 4HKSbO0.20H O 100 parts of the former will oxidize of the latter: * Poggend. Annal., 95, 217. ANTIMONY. 195 336.64 338.01 336.83 337-93 338-59 335-79 Mean, 337.30, +.29 From this, if KI2Cr207 - 294.64, Sb 119.8. The newer atomic weights found in the previous chapters of this work will be applied to the discussion of all these series further along. It may, however, be properly noted at this point, that the probable errors assigned to the percentages of oxygen in three of Kessler's series are too low. These percentages are calculated from the quantities of KOC103 involved in the several reactions, and their probable errors should be increased with reference to the probable error of the molecular weight of that salt. The necessary calculations would be more laborious than the importance of the figures would warrant, and, accordingly, in computing the final general mean for antimony, Kessler's figures will receive somewhat higher weight than they are legitimately entitled to. Naturally, the concordant results of Dexter, Kessler, and Dumas led to the general acceptance of the value of 122 for antimony as against the lower figure 120 of Schneider. Still, in 1871, Unger * published the results of a single analysis of Schlippe's salt, Na3 SbS4.9H20. This analysis gave Sb = 119.76, if S = 32 and Na = 23, but no great weight could be attached to the determination. It served, nevertheless, to show that the controversy over the atomic weight of antimony was not finally settled. More than ten years after the appearance of Kessler's second paper the subject of the atomic weight of antimony was again taken up, this time by Professor Cooke. His results appeared in the autumn of 1877,t and were conclusive in favor of the lower value, approximately 120. For full *Archiv. der Pharmacie, 197, I94. Quoted by Cooke. t Proceedings American Academy, v. 13. 196 THE ATOMIC WEIGHTS. details the original memoir must be consulted; only a few of the leading points can be cited here. Schneider analyzed a sulphide of antimony which was already formed. Cooke, reversing the method, effected the synthesis of this compound. Known weights of pure antimony were dissolved in hydrochloric acid containing a little nitric acid. In this solution weighed balls of antimony were boiled until the liquid became colorless; subsequently the weight of metal lost by the balls was ascertained. To the solution, which now contained only antimonious compounds, tartaric acid was added, and then, with a supersaturated aqueous sulphhydric acid, antimony trisulphide was precipitated. The precipitate was collected by an ingenious process of reverse filtration, converted into the black modification by drying at 2100, and weighed. After weighing, the Sb2S3 was dissolved in hydrochloric acid, leaving a carbonaceous residue unacted upon. This was carefully estimated and corrected for. About two grammes of antimony were taken in each experiment and thirteen syntheses were performed. In two of these, however, the antimony trisulphide was weighed only in the red modification, and the results were uncorrected by conversion into the black variety and estimation of the carbonaceous residue. In fact, every such conversion and correction was preceded by a weighing of the red modification of the Sb2S3. The mean result of these weighings, if S = 32, gave Sb - 119.994. The mean result of the corrected syntheses gave Sb = 120.295. In these eleven experiments the following percentages of S in Sb2S3 were established: 28.57 28.60 28.57 28.43 28.42 28.53 28.50 28.49 28.58 28.50 28.5 I Mean, 28.5I82, ~.0120 ANTIMONY. 197 These results, confirmatory of the work of Schneider, were presented to the American Academy in 1876. Still, before publication, Cooke thought it best to repeat the work of Dumas, in order to detect the cause of the old discrepancy between the values Sb = 120 and Sb - 122. Accordingly, various samples of antimony trichloride were taken, and purified by repeated distillations. The final distillate was further subjected to several recrystallizations from the fused state; or, in one case, from a saturated solution in bisulphide of carbon. The portions analyzed were dissolved in concentrated aqueous tartaric acid, and precipitated by silver nitrate, many precautions being observed. The silver chloride was collected by reverse filtration, and dried at temperatures from 110~ to 120~. In one experiment the antimony was first removed by HS. Seventeen experiments were made, giving, if Ag = 108 and C1 - 35.5, a mean value of Sb - 121.94. If we reduce to a common standard, Cooke's analyses give, as proportional to 100 parts of AgCl, the quantities of SbC13 stated in the third column: 1.5974 grm. SbC13 gave 3.0124 grm. AgC1. 53.028 1.2533,, 2.3620 " 53.06i.8876 1.6754 " 52.978.8336 I.5674 53.184.5326 I.002I " 53. 148.7270 1.369I " 53. IO 1.2679 " 2.3883 " 53.o88 1.9422 3.6646 " 52.999 1.7702 " 3-3384 " 53.025 2.5030 4.7184 " 53.048 2. 1450 4.04I0 " 53.08I 1.7697 3.3281 " 53. I75 2.3435 4.4I57 53.072 1.3686 " 2.5813 " 53.020 I.8638 " 3.5146' 53.030 2.0300,, 3.8282 " 53.028 2.4450 " 4.6086 " 53.053 Mean, 53.o66,.o0096 This mean may be combined with that of Kessler's series, as follows: 198 THE ATOMIC WEIGHTS. Kessler~ ___ ____~____-53.623, -.oI05 Cooke-_______- ____ 53.o66, 4-.o0096 General mean ___.-..... 53.2311, -.008 The results thus obtained with SbCl3 confirmed Dumas' determination of the atomic weight of antimony as remarkably as the syntheses of Sb2S3 had sustained the work of Schneider. Evidently, in one or the other series a constant error must be hidden, and much time was spent by Cooke in searching for it. It was eventually found that the chloride of antimony invariably contained traces of oxychloride, an impurity which tended to increase the apparent atomic weight of the metal under consideration. If was also found, in the course of the investigation, that hydrochloric acid solutions of antimonious compounds oxidize in the air during boiling as rapidly as ferrous compounds; a fact which explains the high values for antimony found by Kessler. In order to render "assurance doubly sure," Professor Cooke also undertook the analysis of the bromide and the iodide of antimony. The bromide, SbBr3, was prepared by adding the finely powdered metal to a solution of bromine in carbon disulphide. It was purified by repeated distillation over pulverized antimony, and by several recrystallizations from bisulphide of carbon. The bromine determinations resembled those of chlorine, and gave, if Ag = 108 and Br = 80, a mean value for antimony of Sbb- 120. Reduced to a common standard, the fifteen analyses give the subjoined quantities of SbBr3 proportional to 100 parts of silver bromide: I.8621 grin. SbBr3 gave 2.9216 grin. AgBr. 63.736.9856 1.5422 63.909 1.8650 it 2.9268 " 63.721 1.5330 it 2.4030 " 63.795 1.3689 " 2. I445 " 63.833 I.2124, I.8991,, 63.84I.94I7 " 1.4749 " 63.848 2.5404 " 3-9755 63.901 1.5269 " 2.3905 " 63.874 1.8604 " 2.9180 " 63-756 1.7298 " 2.7083 " 63.870 ANTIMONY. 199 3.2838 grm. SbBr3 gave 5.I398 grm. AgBr. 63.890 2.3589 " 3.6959 " 63.825 1.3323,, 2.0863 " 63.859 2.6974 " 4.2285 " 63.791 Mean, 63.830, 4-.0oo8 The iodide of antimony was prepared like the bromide, and analyzed in the same way. At first, discordant results were obtained, due to the presence of oxyiodide in the iodide studied. The impurity, however, was removed by subliming the iodide in an atmosphere of dry carbon dioxide. With this purer material, seven estimations of iodine were made, giving, if Ag 108 and I — 127, a value for antimony of Sb =- 120. Reduced to a uniform standard, Cooke's weighings give the following quantities of SbI, proportional to 100 parts of silver iodide: I. I877 grm. SbI3 gave 1.6727 grm. AgI. 7I.00oo5.46Io ".6497 " 70-956 3.2527 " 4.5716 71.150 i.8o68 " 2.5389 " 71.65 I-5970 2.2456 7I.117 2.3201 " 3.2645 7I.071.3496 ".4927 " 70.956 Mean, 7I.o60, 4-.023 Although Cooke's work was practically conclusive, as between the rival values for antimony, his results were severely criticized by Kessler,* who, evidently, had read Cooke's paper in a very careless way. On the other hand, Schneider published in Poggendorff's Annalen a friendly review of the new determinations, which so splendidly vindicated his own accuracy. In reply to Kessler, Cooke undertook still another series of experiments with antimony bromide,t and obtained absolute confirmation of his previous results. To a solution of antimony bromide was added a solution containing a known weight of silver not quite sufficient to precipitate all the bromine. The excess * Berichte d. Deutsch. Chem. Gesell., 12, Io044. I879. -f Amer. Journ. Sci. and Arts, May, i88o. Berichte, 13, 951. 200 THE ATOMIC WEIGHTS. of the latter was estimated by titration with a normal silver solution. Five analyses gave values for antimony ranging from 119.98 to 120.02, when Ag -= 108 and Br - 80. Reduced to a common standard, the weights obtained gave the amounts of SbBr3 stated in the third column as proportional to 100 parts of silver: 2.5032 grm. SbBr3 = 2.2528 grm. Ag. I I I. I I5 2.0567 " 1.8509 " 1. I 19 2.6512 ct 2.3860 " III1II5 3.3053 2.9749 " II.io06 2.7495 " 2.4745 " III.I13 Mean, III111.114, 4-.0014 Schneider,* also, in order to more fully answer Kessler's objections, repeated his work upon the Arnsberg stibnite. This he reduced in hydrogen as before, correcting scrupulously for impurities. The following percentages of sulphur were found: 28.546 28.534 28.542 Mean, 28.54I, -4.0024 These figures confirm his old results, and may be fairly combined with them and with the percentages found by Cooke, as follows: Schneider, early series __.-..... 28.520, +.oo8 " late " 28.541, __.0024 Cooke __ — _____ _. _ _ 28.5182, ~.0120 General mean__..____.._ 28.5385, 4-.0023 We have now before us the following ratios, good and bad, from which to calculate the atomic weight of antimony. The single results obtained by Weber and by Unger, being unimportant, are not included: (I.) Percentage of S in Sb2S3, 28.5385, ~-.0023 (2.) " Sb in Sb204, 79.283, -+-.009o (3.) O needed to oxidize Ioo parts SbCl,, 7.0294, ~.0024 (4.) 0... Sb20,, 10.953, ~_.0075 (5.) 0 Sb, I3.079, -+.0096 Journ. fiir Prakt. Chem., (2,) 22, 13I. ANTIMONY. 201 (6.) K2Cr207: tartar emetic:: Ioo: 337.30, +-.29 (7.) Ag: SbC13:: 100: 70.512, 4-.021 (8.) AgC1: SbCJ3 ~: 100: 53.2311, -.008 (9.) Ag: SbBr3:: 100: 11. II4, -.OOI4 (Io.) AgBr: SbBr3:: Ioo: 63.830, 4-.008 (II.) AgI: SbI3:: OO: 71.o60, 4-.023 Three of these ratios give estimates for the molecular weight of antimony trichloride, and two give corresponding values for the bromide. These values may be combined, as follows: First, for the chloride we haveFrom (3) —--—... __._ SbCl =z 227.094, +-. I5' (7) " = 227.77I, 4-.09I' ~(8)_ ___ __- _228.433, 4-.039 General mean..... " = 228.225, E-.034 Hence Sb - 122.115, +-.055. For the bromide we get: From (9) _- -___ SbBr3 = 358.926, ---.o32 i' (o0)-_ _________ " _ 358.935, 4-.o60 General mean__.... " 358.929, -.029 Hence Sb - 119.625, +.063. From all the data eight values for Sb may be deduced. These fall into two groups; the one near the number 120, the other not far from 122. In making the calculation the atomic weights found in previous chapters are applied; the value selected for chromium being that deduced from Siewert's experiments: I. From SbS,, ratio (I)_ Sb =20. 45, -.045 2. " SbBr _ — 9= iI9.625, 4-.063 Low. 3. " SbI3, ratio (II)- " = I9.665, 4-.179 1 4. " tartar emetic, ratio (6)..... " = 1I8.690, 4-.278 5. " Sb204, ratio (2) " 122.181, 4-.06 6. SbC1_,, --- 22. 115, ~-.055 7. " ratio (4) __- 21.798,.05 igh. 8. " (5) ---------------- 122.053, ~.094 General mean __ " 2.027, 4-.025 General mean of values I to 4__ " 119.935, 4-.036.... 5 " 8__. " = 122.092, 4.035 Although the means of the four lower values and of the four higher values are thus shown to be approximately 202 THE ATOMIC WEIGHTS. equal in weight, we know from Cooke's experiments that the larger mean is vitiated by serious constant errors. Only in value 5, the result calculated from Dexter's experiments, has the constant error not been pointed out. Cooke considers it probable, however, that the Sb2,,04 involved in this work contained traces of some lower oxide, which, if present, would render the atomic weight of antimony apparently too high. Chemically considered, the preponderance of evidence is strongly in favor of values 1 to 3, deduced from the experiments of Schneider and of Cooke. These give a general mean of Sb = 119.955, -.036; or, if O = 16, this becomes Sb =- 120.231. This we may accept as most nearly the true result, and reject the data of Dexter, Dumas, and Kessler altogether. Since this chapter was written, Pfeifer has compared the amount of antimony thrown down electrolytically, with the quantity of silver deposited by the same current in the same time. From rather meagre data he concludes that the atomic weight of antimony, thus determined, may be 121. Additional investigation is promised. The figures thus far published would weigh little as against Cooke's experiments. (Ann. Chem. Pharm., 209, 161. 1881.) BISMUTH. Early in the century the combining weight of bismuth was approximately fixed through the experiments of Lagerhjelm.* Effecting the direct union of bismuth and sulphur, he found that ten parts of the metal yield the following quantities of trisulphide: 12.2520 12.2065 12.2230 12.2465 Mean, 12.2320 * Annals of Philosophy, 4, 358. I814. Results adopted by Berzelius. BISMUTH. 203 Hence B - 215 in round numbers, a value now known to be much too high. Lagerhjelm also oxidized bismuth with nitric acid, and, after ignition, weighed the trioxide thus formed. Ten parts of metal gave the following quantities of Bi2 O 3: II.I382 I1.1275 Mean, 11. 13285 Hence, if O = 16, Bi = 211.85, a figure still too high. In'1851 the subject of the atomic weight of bismuth was taken up by Schneider,* who, like Lagerhjelm, studied the oxidation of the metal with nitric acid. The work was executed with a variety of experimental refinements, by means of which every error due to possible loss of material was carefully avoided. For full details the original paper must be consulted; there is only room in these pages for the actual results, as follows. The figures represent the percentages of Bi in Bi 02: 89.652 89.682 89.644 89.634 89.656 89.666 89.655 89.653 Mean, 89.6552, --.0034 Hence Bi = 207.523, +.082; or, if O = 16, Bi = 208.001. Finally, we come to the results obtained by Dumas.t Bismuth trichloride was prepared by the action of dry chlorine upon bismuth, and repeatedly rectified by dis_ tillation over bismuth powder. The product was weighed in a closed tube, dissolved in water, and precipitated with sodium carbonate. In the filtrate, after strongly acidulating * Poggend. Annal., 82, 303. I85I. t Ann. de Chim. et de Phys., (3,) 55, I76. I859. 204 THE ATOMIC WEIGHTS. with nitric acid, the chlorine was precipitated by a known amount of silver. The figures in the third column show the quantities of BiCl3 proportional to 100 parts of silver: 3.506 grm. BiC13 = 3.545 grn. Ag. 98.900oo I.I49 " I. 68 " 98.373 1.5965 " x.629 " 98.005 2. 1767 " 2.225 " 97.829 3.081,, 3- 44 " 97.996 2.4158 " 2.470 " 97.806 1.7107 i" 1.752 " 97.643 3.523 " 3.6055 " 97.712 5.241 " 5-36I " 97.762 Mean, 98.003, -.o09o Hence Bi - 210.464, +.294. The first three of the foregoing series of experiments were made with slightly discolored material, and may therefore be rejected. The remaining six percentages give a mean of 97.791; whence Bi = 209.78; or, if 0 = 16, Bi =- 210.26. As between the unaccordant results of Schneider and of Dumas, those of the former chemist are probably nearest correct. Hiis method of determination was the more reliable, and the details which he gives concerning his manipulations afford strong presumptions of accuracy. Doubtless the bismuth trichloride used by Dumas, contained, like the corresponding antimony compounds, traces of oxychloride. We may fairly assume, for all practical purposes, that the atomic weight of bismuth cannot be far from 208. TIN. Stannic oxide and stannic chloride are the compounds which have been studied in estimating the atomic weight of tin. The composition of stannic oxide has been fixed in two ways; by synthesis from the metal, and by reduction in hydrogen. For the first method we may consider the work of Berzelius, Mulder and Vlaanderen, and Dumas. TIN. 205 Berzelius * oxidized 100 parts of tin by nitric acid, and found that 127.2 parts of SnO2 were formed. The work done by Mulder and Vlaanderen t was done in connection with a long investigation into the composition of Banca tin, which was found to be almost absolutely pure. For the atomic weight determinations, however, really pure tinwas taken, prepared from pure tin oxide. This metal was oxidized by nitric acid, with the following results. 100 parts of tin gave of SnO2: 127.56-Mulder. 127.56-Vlaanderen. I27.43- i Mean, 127.517, 4-.029 Dumas T oxidized pure tin by nitric acid in a flask of glass. The resulting SnO2 was strongly ignited, first in the flask, and afterwards in platinum. His weighings, reduced to the foregoing standard, give for dioxide from 100 parts of tin the amounts stated in the third column: I2.443 grm. Sn gave 15.820 grm. SnO2. 127.14 I5-976 " 20.301 " 127.07 Mean, 127. I05, 4-.024 In an investigation later than that previously cited, Vlaanderen II found that when tin was oxidized in glass or porcelain vessels, and the resulting oxide ignited in them, traces of nitric acid were retained. When, on the other hand, the oxide was strongly heated in platinum, the latter was perceptibly attacked, so much so as to render the results uncertain. He therefore, in order to fix the atomic weight of tin, reduced the oxide by heating it in a porcelain boat in a stream of hydrogen. Two experiments gave Sn - 118.08, and Sn = 118.24. These, when O = 16, become, if reduced to the above common standard, * Poggend. Annal., 8, 77. t Journ. fiir Prakt. Chem., 49, 35. I849. t Ann. Chem. Pharm., 11JI3, 26. II Jahresbericht, i858, I83. 206 THE ATOMIC WEIGHTS. I27. Ioo 127.o64 Mean, I27.o82, 4-.012 We have now four series of results showing the quantity of SnO2 formed from 100 parts of tin. To Berzelius' single value may be assigned the probable error of a single experiment in Mulder and Vlaanderen's series: Berzelius_- _.... _ 127.200, -4-.04I-Oxidation. Mulder and Vlaanderen __ I27.517, ~.029 " Dumas- -- __ __ __. 127.105, 4-.024- " Vlaanderen ______ ___ 127.082, 4-.oI2-Reduction. General mean-........ I127. I43, 4-.0098 Dumas, in the paper previously quoted, also gives the results of some experiments with stannic chloride, SnCl4. This was titrated with a solution containing a known weight of silver. From the weighings given, 100 parts of silver correspond to the quantities of SnCl, named in the third column: 1.839 grm. SnCl =- 3.054 grmin. Ag. 60.216 2.665,, 4.427 " 6o. I99 Mean, 60.207, ~-.oo6 All these data properly combined give us the following values for the atomic weight of tin: From SnO2 _.-....Sn = 117.624, ~.050 " SnC14_ -__, _ __- " I I7.832, ~.067 General mean-.____ "-II7.698, ~-.040 If O 16, this becomes Sn = 117.968. TITANIUM. 207 TITANIUM. The earliest determinations of the atomic weight of titanium are due to Heinrich Rose.* In his first investigation he studied the conversion of titanium sulphide into titanic acid, and obtained erroneous results; later, in 1829, he published his analyses of the chloride.t This compound was purified by repeated rectifications over mercury and over potassium, and was weighed in bulbs of thin glass. These were broken under water in tightly stoppered flasks; the titanic acid was precipitated by ammonia, and the chlorine was estimated as silver chloride. The following results were obtained. In a fourth column I give the TiO2 in percentages referred to TiCl, as 100; and in a fifth column the quantity of TiC14 proportional to 100 parts of AgCl: TiCI4. TiO2. AgCi. Per cent. TiO2. AgCl Ratio..885 grm..379 grm. 2.66i grm. 42.825 33.258 2.6365 " 1.120 " 7.954 " 42.481 33- 147 I.7157 ".732 " 5.172 " 42.665 33 I73 3.0455 " 1.322 " 9. 98 " 43.423 33. oo 2.4403 " 1.056 " 7-372 " 43.273 33. 102 Mean, 42.933, -4-.12 33-I56, -.oi9 If we directly compare the AgCl with the TiO2 we shall find 100 parts of the former proportional to the following quantities of the latter: 14.243 14.08I 14. I53 14.373 14.324 Mean, I4.235, -.036 From all these figures we can get three values for Ti, thus: * Gilbert's Annalen, 1823, 67 and 129. t Poggend. Annal., 15, 145. Berz. Lehrbuch, 3, 1210. 208 THE ATOMIC WEIGHTS. From per cent. TiO2. Ti - 50.493, -1.410 " AgC1: TiC14_____ " - 48.232, 4-.127 AgC1: TiO2, -- 49.523, 4.206 General mean-. _. "-= 48.710, 4-.105 These results will be discussed further along in connection with others. Shortly after the appearance of Rose's paper, Mosander * published some figures giving the percentages of oxygen in titanium dioxide, from which a value for the atomic weight of titanium was deduced. Although no details are furnished as to experimental methods, and no actual weighings are given, I cite his percentages for whatever they may be worth: 40. 814 40.825 40.610 40. i8o 40.107 40.050 40.780 40.660 39.830 Mean, 40.428 These figures give values for Ti ranging from 46.277 to 48.231; or, in mean, Ti = 47.045. They are not, however, sufficiently explicit to deserve any further consideration. It will be noticed that the highest value nearly coincides with Rose's lowest. In 1847 Isidor Pierre made public a series of important determinations.t Titanium chloride, free from silicon and from iron, was prepared by the action of chlorine upon a mixture of carbon with pure, artificial, titanic acid. This chloride was weighed in sealed tubes, these were broken under water, and the resulting hydrochloric acid was titrated with a standard solution of silver after the method * Berz. Jahresbericht, IO, Io8. I83I. t Ann. de Chim. et Phys., (3,) 20, 257. TITANIUM. 209 of Pelouze. I subjoin Pierre's weighings, and add, in a third column, the ratio of TiCl4 to 100 parts of silver: Ti Cl4. 4 -i. Ratio..8215 grmin. 1.84523 grm. 44.520 ~7740 " 1.73909 " 44.506 ~7775 " 1.74613 " 44-527.7I60 " 1.61219 " 44.4I2.8085 " 1.82344 " 44.339.6325 " 1.42230' 44-470.8155 1i.83705 " 44.392.8165 " 1.83899 " 44-399.8o65 " 1.81965 " 44.322 Mean, 44.432, 4-.0173 It will be seen that the first three of these results agree well with each other and are much higher than the remaining six. The last four experiments were made purposely with tubes which had been previously opened, in order to determine the cause of the discrepancy. According to Pierre, the opening of a tube of titanium chloride admits a trace of atmospheric moisture. This causes a deposit of titanic acid near the mouth of the tube, and liberates hydrochloric acid. The latter gas being heavy, a part of it falls back into the tube, so that the remaining chloride is richer in chlorine and poorer in titanium than it should be. Hence, upon titration, too low figures for the atomic weight of titanium are obtained. Pierre accordingly rejects all but the first three of the above estimations: From all of Pierre's._-_-_- Ti - 49.889, 4-.o96 " the first three _-__ —-- " = 50.259, L-.063 The memoir of Pierre upon the atomic weight of titanium was soon followed by a paper from Demoly,* who obtained much higher results. IIe also started out from titanic chloride, which was prepared from rutile. The latter substance was found to contain 1.8 per cent. of silica; whence Demoly inferred that the TiC14 investigated by Rose and by Pierre * Ann. Chem. Pharm., 72, 214. 1849. Berz. Jahresb., 30, 58. 14 210 THE ATOMIC WEIGHTS. might have been contaminated with SiCl4, an impurity which would lower the value deduced for the atomic weight under consideration. Accordingly, in order to eliminate all such possible impurities, this process was resorted to: the chloride, after rectification over mercury and potassium, was acted upon by dry ammonia, whereupon the compound TiC14.4NH3 was deposited as a white powder. This was ignited in dry ammonia gas, and the residue, by means of chlorine, was reconverted into titanic chloride, which was again repeatedly rectified over mercury, potassium, and potassium amalgam. The product boiled steadily at 135~. This chloride, after weighing in a glass bulb, was decomposed by water, the titanic acid was precipitated by ammonia, and the chlorine was estimated in the filtrate as silver chloride. Three analyses were performed, yielding the following results. I give the actual weighings: 1.470 grm. TiC14 gave 4.241 grm. AgC1 and.565 gri. TiO2. 2.330 6.752 ".8oi " 2.880 8-330 I.o88 " The ".801" in the last column is certainly a misprint for.901. Assuming this correction, the results may be given in three ratios, thus: Per cent. TiO2from TXiC4. TiC4. oo AggC1. TiO2. 0oo AgCZ. 38.435 34.662 13.322 38.669 34.508 13.344 37-778 34-574 I3.o6I Mean, 38.294, -.I8o 34.58I, -.030 13.242, o.06I These three ratios give three widely divergent values for the atomic weight of titaniun; From per cent. TiO, __ _Ti = 36.063, +_.519 " AgCl: TiO,2 -._... " - 43.84I, -.350 " AgCl: TiC14-......._ " _ 56.386, +-.I8I General mean....." 52.191, --.153 The value assumed by Demoly is 56; who employs but one ratio and ignores practically the others. TITANIUM. 211 Upon comparing Demoly's figures with those obtained by Rose, certain points of similarity are plainly to be noted. Both sets of results were reached by essentially the same method; and in both the discordance between the percentages of titanic acid and of silver chloride is glaring. This discordance can rationally be accounted for by assuming that the titanic chloride was in neither case absolutely what it purported to be; that, in brief, it must have contained impurities; such for example as hydrochloric acid, as shown in the experiments of Pierre, or possibly traces of oxychlorides. Considerations of this kind also throw doubt upon the results attained by Pierre, for he neglected the direct estimation of the titanic acid altogether, thus leaving us without means for correctly judging as to the character of his material. In fact, not one of the determinations of the atomic weight of titanium can be regarded as trustworthy. All depend upon the chloride, and the volatile chlorides of metals are as a class especially liable to contaminations of a kind most difficult to recognize. Possibly a series of good determinations might be based upon analyses of some of the titanofluorides. I subjoin a combination of the foregoing mean values, feeling that such a general average is a little better than any one set of determinations taken singly: From Rose's analyses ___.Ti = 48.7.Io, -.Io05 Pierre's " -- ___ — " 49.889, 4-.o96 Demoly's _ it ___ A_ 52. 19I, -.I53 General mean ___-_-_ " = 49.846, -.064 Or, if O = 16, Ti = 49.961. This mean agrees with the average of all of Pierre's experiments. 212 THE ATOMIC WEIGHTS. ZIRCONIUM. The atomic weight of zirconium has been determined by Berzelius, by Hermann, and by Marignac. Berzelius* ignited the neutral sulphate, and thus ascertained the ratio in it between the ZrO2 and the SO3. Putting S03 at 100, he gives the following proportional quantities of ZrO2: 75.84 75.92 75.80 75.74 75.97 75.85 Mean, 75.853, -+.023 Hence Zr = 89.255, --.039; or, if 0 = 16, then Zr89.461. Hermann'st estimhnate of the atomic weight of zirconium was based upon analyses of the chloride, concerning which he gives no details or weighings. From sublimed zirconium chloride he finds Zr = 831.8, when 0 - 100; and from two lots of the basic chloride 2ZrOC12.9H0O, Zr = 835.65 and 851.40 respectively. The mean of all three is 839.62; whence, with moder'n formule and 0 = 15.9633, Zr becomes -- 89.354. Marignac's results I were obtained by analyzing the double fluoride of zirconium and potassium. His weights are as follows: I.oo000 grm. gave.431 grm. ZrO2 and.6I3 grin. K2SO4. 2.000 ".864 " 1.232 ".654 ".282 ".399 " 5.000 " 2. I69 " 3.o078 These figures give us three ratios. A, the ZrO2 from 100 * Poggend. Annal., 4, 126. I825. tJourn. fur Prakt. Chem., 31, 77. Berz. Jahresb., 25, 147.. Ann. Chim. Phys., (3,) 60, 270. i86o. ZIRCONIUM. 213 parts of salt; B, the K2SO4 from 100 parts of salt; and C, the ZrO, proportional to 100 parts of K2SO4: A. B. C. 43. 100 61.300 70.3Io 43.200 6 I.600 70.130 43. I19 6I.ooo 70.677 43.380 61.56o 70.468 Mean, 43.200, 4-.043 61.365, --.094 70-396, 4-.079 From A - ------ -...... — Zr = 89.775, -4-.216 " B —-— _ ______ _ _"- 91.408, --.437 C _" - 90.476, _.138 General mean _.,_ — _ 90.328, --. I 13 Or, if O = 16, Zr = 90.536. Combining with Berzelius' work we get this result: Berzelius_ __________~_____ Zr - 89.255, 4-.039 Marignac " =90.328, -4-.113 General mean- -__.__ " - 89.367, 4.037 Or, if O = 16, Zr = 89.573. These figures need little criticism. They show conclusively that the atomic weight of zirconium ought to be redetermined. Probably the method employed by Berzelius was the best with respect to manipulation, while on the other hand it is likely that Marignac worked with purer material. Hermann's experiments could hardly have yielded certain results, since the zirconium chloride might so easily become contaminated with traces of moisture and thence of oxygen. 214 THE ATOMIC WEIGHTS. THORIUM. The atomic weight of thorium has been determined from analyses of the sulphate, oxalate, formate, and acetate, with widely varying results. The earliest figures are due to Berzelius,* who worked with the sulphate, and with the double sulphate of potassium and thorium. The thoria was precipitated by ammonia, and the sulphuric acid was estimated as BaSO4. The sulphate gave the following ratios in two experiments. The third column represents the weight of ThO2 proportional to 100 parts of BaSO4:.6754 grm. ThO2 = 1.159 grm. BaSO4. Ratio, 58.274 1.0515 t" 1.832 " 57.396 The double potassium sulphate gave.265 grm. ThO2,.156 grm. SO,3, and.3435 K2SO4. The S03, with the Berzelian atomic weights, represents.4537 grm. BaSO4. Hence 100 BaSO4 is equivalent to 58.408 ThO,. This figure, combined with the two previous values for the same ratio, give a mean of 58.026, +-.214. HIence ThO2 = 269.940, -.997. From the ratio between the K2SO4 and the ThO2 in the double sulphate, ThO2 = 268.284. In 1861 new determinations were published by Chydenius,t whose memoir is accessible to me only in an abstract: which gives results without details. Thoria is regarded as a monoxide, ThO, and the old equivalents (O = 8) are used. The following values are assigned for the molecular weight of ThO, as found from analyses of several salts: From Sulphate. From K. Th. Sulphate. 66.33 67.02 67. I3 67.75 68.03 Mean, 67.252, ~.201 * Poggend. Annal., I6, 398. 1829. Lehrbuch, 3, 1224. t Kemisk unders6kning af Thorjord och Thorsalter. Helsingfors, I86i. An academic dissertation. t Poggend. Annal., I 19, 55. 1863. THORIUM. 215 From Acetate. From Formate. From Oxalate. 67.31 68.o6 65.87 } Two results 66.59 67.89 65.95 by Berlin. 67.27 68.94 65.75 67.06 65.I3 68.40 Mean, 68.297, 4-.219 66.54 65.85 Mean, 67.326, --.20I Mean, 65.85, 4-.I23 We may fairly assume that these figures were calculated with 0 8, C = 6, and S = 16. Correcting by the values for these elements which have been found in previous chapters, ThO2 becomes as follows: From sulphate_ ______ThO2 - 268.584, 4-.803' acetate-_______ " = 268.735, -.805 " formate.__.___ " = 272.586, 4.877 oxalate_______ " - 262.804, -4 — 493 The single result from the double potassium sulphate is included with the column from the ordinary sulphate, and the influence of the atomic weight of potassium is ignored. Chydenius was soon followed by Marc Delafontaine, whose researches appeared in 1863.* This chemist especially studied thorium sulphate; partly in its most hydrous form, partly as thrown down by boiling. In Th(SO,)2.9H20, the following percentages of ThO, were found: 45.08 44.90 45.06 45.21 45.06 Mean, 45.062, -.0332 Hence ThO2 - 263.637, _+.256. The lower hydrate, 2Th(SO4)2.9HO, was more thoroughly investigated. The thoria was estimated in two ways; first, (A,) by precipitation as oxalate and subsequent ignition; second, (B,) by direct calcination. These percentages of ThO2 were found: * Arch. des Sci. Phys. et Nat., (2,) I8, 343 216 THE ATOMIC WEIGHTS. 52.83 52.52 A. 52.72 52.13 J 52-47 1 52'49 52.53 52. 13 52.43 B. 52.60 52.40 52.96 52.82 J Mean, 52.511, -.047 Hence ThO2 = 266.025, -+.363. In three experiments with this lower hydrate the sulphuric acid was also estimated, being thrown down as barium sulphate after removal of the thoria: 1.2425 grm. gave.400 S03. (I.I656 grm. BaSO4.) I.138 ".366 " (i.0665 " ) ~734 ".2306" (.6720 " ) The figures in parenthesis are reproduced by myself from Delafontaine's results, he having calculated his analyses with O = 100, S = 200, and Ba - 857. These data may be reduced to a common standard, so as to represent the quantity of 2Th(S0,)2.9H20 equivalent to 100 parts of BaSO4. We then have the following results: i06.597 i06.704 109.226 Mean, I07.509, 4-.585 Hence ThO2 = 259.555, ti 2.725. Delafontaine seems himself to have calculated from the ratio between the percentages of SO, and ThO2; whence, with our revised values for S, Ba, and 0, ThO2 = 262.643. Delafontaine's work was soon confirmed by Hermann,* * Journ. fiir Prakt. Chem., 93, 114. THORIUM. 217 who published a single analysis of the lower hydrated sulphate, as follows: ThO - 52.87 SO........... 32.II HEO _ -_ _ _ ___15.02 100.00 Hence, from the ratio between SO, and ThO,, ThO, = 263.030. Probably the SO3 percentage was loss upon calcination. The latest, and probably also the best determinations, are those of Cleve,* whose results, obtained from both the sulphate and the oxalate of thorium, agree admirably. The anhydrous sulphate, calcined, gave the subjoined percentages of thoria: 62.442 62.477 62.430 62.470 62.357 62.366 Mean, 62.423, 4-.014 Hence ThO2 = 265.380, -.123. The oxalate was subjected to a combustion analysis, whereby both thoria and carbonic acid could be estimated. From the direct percentages of these constituents no accurate value can be deduced, there having undoubtedly been moisture in the material studied. From the ratio between CO2 and ThO2, however, good results are attainable. This ratio I put in a fourth column, making the thoria proportional to 100 parts of carbon dioxide: Oxalate. Th 02. Co2. Ratio. 1.7135 grm. I.oI89 grm..6736 grm. 151.262 1.3800 ".82IO ".5433 " 15. 114 I. I850 ".7030 ".4650 " 151.83 1.0755 ".6398 ".4240 " I50.896 Mean, 1.51.114, 4-.053 Hence ThO2 = 265.357, i.104. * K. Svenska Vet. Akad. Handlinger. Bd. 2, No. 6. I874. 218 THE ATOMIC WEIGHTS. There are now before us twelve estimates for the molecular weight of thoria. Two of these represent single experiments, and have no probable error attached to them; namely, the one due to Hermann, and the one deduced from Berzelius' K2SO4: ThO2 ratio. A third value, from Delafontaine's sulphuric acid estimations, has so high a probable error that it could be rejected without influencing the general mean. These three values might all be excluded without serious objection; but it is perhaps better to arbitrarily assign them equal weight, average them together, and give their mean the same probable error as that which attaches to Berzelius' BaSO4: ThO2 series. This mean is indicated as "A" in the following combination: Value "A"__ _ThO2 263.623, -4-.997 Berzelius-_-______ ______ ___ " 269.940, +-.997 Chydenius-Sulphate -.....________ " 268.584, -4-.803 "' Acetate _-____ —______" " 268.735, -+.805 a' Formate _ " — 272.586, -4-.877 di Oxalate "- " = 262.804, _+.493 Delafontaine-Higher hydrate - ----- " = 263.637, _.256 i' Lower it - -- 266.025, 4-.363 Cleve-Sulphate " 265.380, q-.123 " Oxalate______ = 265.357, --.I04 General mean _ —------ -. " - - 265.341, -.072 Hence Th = 233.414, -+.0725; or, if 0 = 16, Th233.951. These values vary from those derived from Cleve's experiments alone only in the second decimal. GALLIUM. Gallium has been so recently discovered, and obtained in such small quantities, that its atomic weight has not as yet been determined with much precision. The following data were fixed by the discoverer, Lecoq de Boisbaudran: * * Journ. Chem. Soc., I878, p. 646. INDIUM. 219 3.1044 grammes gallium ammonium alum, upon ignition, left.5885 grm. Ga2 0,. Hence Ga = 68.071. If O - 16, Ga = 68.233..4481 grammes gallium, converted into nitrate and ignited, gave.6024 grm. Ga2 03. Hence Ga = 69.538. If O = 16, Ga -- 69.693. These values, assigned equal weight, give these means: If 0 15.9633, Ga = 68.854. If 0 - 16, Ga = 68.963. In brief, for all practical purposes, 69 may be assumed as the atomic weight of gallium. INDIUM. Reich and Richter, the discoverers of indium, were also the first to determine its atomic weight.* They dissolved weighed quantities of the metal in nitric acid, precipitated the solution with ammonia, ignited the precipitate, and ascertained its weight. Two experiments were made, as follows:.5135 grm. indium gave.6243 grm. In203..699,.85i5 " Hence, in mean, In = 110.61, if 0 = 16; a value known now to be too low. An unweighed quantity of fresh, moist indium sulphide was also dissolved in nitric acid, yielding, on precipitation,.2I05 grm. In203 and.542 grm. BaSO4. Hence, with BaSO4 = 233, In = 111.544; also too low. Soon after the publication of Reich and Richter's paper the subject was taken up by Winkler.t He dissolved indium in nitric acid, evaporated to dryness, ignited the residue, and weighed the oxide thus obtained.' Journ. fiur Prakt. Chem., 92, 484. t Journ. fur Prakt. Chem., 94, 8. 220 THE ATOMIC WEIGHTS..5574 grm. In gave.6817 grm. In203..666i ".844 "d.5011 ".6126 " Hence, in mean, if 0 - 16, In = 107.76; a result even lower than the values already cited. In a later paper by Winkler* better results were obtained. Two methods were employed. First, metallic indium was placed in a solution of pure, neutral, sodio-auric chloride, and the amount of gold precipitated was weighed. I give the weighings and, in a third column, the amount of indium proportional to 100 parts of gold: In. Au. Ratio..447I grm..8205 grm. 57.782.8445 " 1.4596 " 57.858 Mean, 57.820, 4-.o026 Hence, if Au = 196.155, -.095, In = 113.417, -+-.074. Winkler also repeated his earlier process, converting indium into oxide by solution in nitric acid and ignition of the residue. An additional experiment, the third as given below, was made after the method of Reich and Richter. The third column gives the percentage of In in In 03: 1.124 grm. In gave 1.3616 grm. In203. Per cent., 82.550 I.015 " 1.2291 " " 82.581.6376 ".7725 " " 82.537 These figures were confirmed by a single experiment of Bunsen's,t published simultaneously with the specific heat determinations which showed that the oxide of indium was n111203, and not InO as had been previously supposed: I.0592 grin. In gave 1.2825 grm. In20O. Per cent. In, 82.589 For convenience we may add this figure in with Winkler's series, which gives us a mean percentage of In in In203 of 82.564, --.0082. Hence, if 0 = 15.9633, --.0035, In - 113.385, -.060. Journ. fur Prakt. Chem., 102, 282. t Poggend. Annal., 141, 28. CERIUM. 221 Combining results, we have the following general mean: From gold series ____..-...In _ 113.417, 4-.074 " oxide " ____ II3.385, -.o6o General mean _... I._-= I I3.398, ~.047 Or, if 0 = 16, In 113.659. CERIUM. Although cerium was discovered almost at the beginning of the present century, its atomic weight was not properly determined until after the discovery of lanthanum and didymium by Mosander. In 1842 the investigation was undertaken by Beringer,* who employed several methods. His cerium salts, however, were all rose-colored, and therefore were not wholly free from didymium; and his results are further affected by a negligence on his part to fully describe his analytical processes. First, a neutral solution of cerium chloride was prepared by dissolving the carbonate in hydrochloric acid. This gave weights of ceroso-ceric oxide and silver chloride as follows. The third column shows the amount of CeO2 proportional to 100 parts of AgCl: Ce 02. AgCI. Ratio..5755 grm. I.4I9 grm. 40.557.6715 " 1.6595" 40-464. 1300 " 2.786 " 40.560.5366 " 1.3316 40.297 Mean, 40.469, 4-.045 The analysis of the dry cerium sulphate gave results as follows. In a fourth column I show the amount of CeO proportional to 100 parts of BaSO4: *Ann. Chem. Pharm., 42, 134. 222 THE ATOMIC WEIGHTS. Sulphate. Ce02. BaSO4. Ratio. 1.379 grmn..8495 grm. 1.711 grin. 49.649 1.276 ".7875 " I.580 " 49.836 1.246 ".7690 ".543 " 49.838 I-553' 9595 " 1.921 " 49.948 Mean, 49.819, —.042 Beringer also gives a single analysis of the formate and the results of one conversion of the sulphide into oxide. The figures are, however, not valuable enough to cite. The foregoing data involve one variation from Beringer's paper. Where I put CeO, as found he puts CeO,. The latter is plainly inadmissible, although the atomic weights calculated from it agree curiously well with some other determinations. For instance, in the chloride series, the assumption of Ce, 03 as the formula of the oxide obtained, gives Ce = 137.749, while CeO, makes Ce = 141.636. The former agrees with the results of Wolf, Wing, and others quite fairly; the latter is near the value obtained by Biihrig. Obviously, the presence of didymium in the salts analyzed should tend to raise rather than to lower the apparent atomic weight of cerium. Shortly after Beringer, Hermann* published the results of one experiment. 23.532 grm. of anhydrous cerium sulphate gave 29.160 grm. of BaSO4. Hence 100 parts of the sulphate correspond to 123.926 of BaSO4. In 1848 similar figures were published by Marignac,t who found the following amounts of BaSO, proportional to 100 of dry cerium sulphate: 122.68 122.00 122.51 Mean, 122.40, --. I38 If we give Hermann's single result the weight of one experiment in this series, and combine, we get a mean value of 123.019, ~.113. * Journ. fiir Prakt. Chem., 30, I85. 1843. t Arch. des Sciences Phys. et Nat., (I,) 8, 273. I848. CERIUM. 223 Still another method was employed by Marignac. A definite mixture was made of solutions of cerium sulphate and barium chloride. To this were added, volumetrically, solutions of each salt successively, until equilibrium was attained. The figures published give maxima and minima for the BaCl, proportional to each lot of Ce2 (SO)3. In another column, using the mean value for BaCl2 in each case, I put the ratio between 100 parts of this salt and the equivalent quantity of sulphate. The latter compound was several times recrystallized: Ce,(S04)3. BaCi2. Ratio. First crystallization I I.o grm. I 1.990o - 12.050 grm. 91.606. " i -- I3.I94 "' I4.365 - 14.425 " 91.657 Second " __ 13.96i " 15.225 - 15.285 " 91.518 C C. __ 12.627 " I3.76I- 13.821 9I1559. " -- 11.915 " 12.970 - 13.030 " 91.654 Third " 14.888 " I6.223 - I6.283 " 91.602.... -- 14.113 " I5.383 - 15.423 " 91.755 Fourth " __ I3. II " 14.270 - I4-330 " 91.685 __ I3970 " 15.223 - I5.283 " 91.588 Mean, 91.625, -+.oi6 Omitting the valueless experiments of Kjerulf,* we come next to the figures published by Bunsen and Jegel t in 1858. From the air dried sulphate of cerium the metal was precipitated as oxalate, which, ignited, gave CeO2. In the filtrate from the oxalate the sulphuric acid was estimated as BaSO4: 1.5726 grm. sulphate gave.7899 grm. CeO2 and 1.6185 grm. BaSO4. I.6967 ".8504 " 1.7500 " Hence, for 100 parts BaSO4, the CeO2 is as follows: 48.804 48.575 Mean, 48.689, __.077 One experiment was also made upon the oxalate:.3530 grinm. oxalate gave.1913 CeO2 and.05o6 HO. Hence, in the dry salt, we have 63.261 per cent. of CeO2. * Ann. Chem. Pharmn., 87, 12. t Ann. Chem. Pharm., 105, 45. 224 THE ATOMIC WEIGHTS. In each sample of CeO2 the excess of oxygen over true Ce2,,03 was estimated by an iodometric titration; but the data thus obtained need not be further considered. In two papers by Rammelsberg * data are given for the atomic weight of cerium, as follows. In the earlier paper cerium sulphate is analyzed, the cerium being thrown down by caustic potash, and the acid precipitated from the filtrate as barium sulphate:.4I3 grm. Ce2(SO4)a gave.244 grm. CeO2 and.513 grm BaSO4. Hence 100 BaSO4 = 47.563 CeO2, a value which may be combined with others, thus; this figure being assigned a weight equal to one experiment in Bunsen's series: Beringer 49.819, -.042 Bunsen and Jegel -___ ___ __...___ 48.689, ~.077 Rammelsberg _ — _ _L 47.563,. I o8 General mean- _ 49.360, -.035 It should be noted here that this mean is somewhat arbitrary, since Bunsen and Rammelsberg's cerium salts were undoubtedly. freer from didymium than the material studied by Beringer. In his later paper Rammelsberg gives these figures concerning cerium oxalate. 100 parts gave 10.43 of carbon and 21.73 of water. Hence the dry salt should yield 48.862 per cent. of C02, whence Ce = 137.83. In all of the foregoing experiments the ceroso-ceric oxide was somewhat colored, the tint ranging from one shade to another of light brown according to the amount of didymium present. Still, at the best, a faint color remained, which was supposed to be characteristic of the oxide itself. In 1868, however, some experiments of Dr. C. Wolf t were posthumously made public, which went to show that pure cerosoeerie oxide is white, and that all samples previously studied were contaminated with some other earth, not necessarily didymium but possibly a new substance, the removal of * Poggend. Annal., 55, 65; Io8, 44. t Amer. Journ. Science and Arts, (2,) 46, 53. CERIUM. 225 which tended to lower the apparent atomic weight of cerium very perceptibly. Cerium sulphate was recrystallized at least ten times. Even after twenty recrystallizations it still showed spectroscopic traces of didymium. The water contained in each sample of the salt was cautiously estimated, and the cerium was thrown down by boiling concentrated solutions of oxalic acid. The resulting oxalate was ignited with great care. I deduce from the weighings the percentage of CeO2 given by the anhydrous sulphate: SuGlPhate. Water. CeO2. Per cent. CeO2. 1.4542 grm..I94I9 grm..76305 grm. 60.559 I.4I04 ".I898 ".7377 " 6o.437 1.35027 ".820 ".70665 " 60.487 Mean, 60.494, 4-.024 After the foregoing experiments the sulphate was further purified by solution in nitric acid and pouring into a large quantity of boiling water. The precipitate was converted into sulphate and analyzed as before: Sulphate. Water. Ce 02. Per cent. CeO2. 1.4327 grm..2733 grm..69925 grm. 60. 311 1.5056 ".2775 ".7405 " 60.296 1.44045 ".2710 ".7052 " 60.300 Mean, 60.302, 4-.004 From another purification the following weights were obtained: 1.4684 grm..I88o grm..7717 grm. 60.270 per cent. A last purification gave a still lower percentage: 1.3756 grm..1832 grI..7 86 grm. 60.265 per cent. The last oxide was perfectly white, and was spectroscopically free from didymium. In each case the CeO, was titrated iodometrically for its excess of oxygen. It will be noticed that in the successive series of determinations the percentage of CeO2 steadily and strikingly diminishes, to an extent for which no ordinary impurity of didymium can 15 226 THE ATOMIC WEIGHTS. account. The death of Dr. Wolf interrupted the investigation, the results of which were edited and published by Professor F. A. Genth. The experiments of Wolf seem to have hitherto escaped general notice, except from Wing, who has partially verified them.* This chemist, incidentally to other researches, purified some eerium sulphate after the method of Wolf, and made two similar analyses of it, as follows: Sulphate. Water. CeO2. Per cent. CeO2. 1.2885 grn..1707 grm..6732 grm. 60.225 1.4090 ".1857 ".7372 " 60.263 Mean, 6o.244, ~.012 Th!e ceroso-ceric oxide in this case was perfectly white. The cerium oxalate which yielded it was precipitated boiling by a boiling concentrated solution of oxalic acid. The precipitate stood twenty-four hours before filtering. We may now combine the results of Wolf and of Wing, as follows. The two concordant experiments of Wolf's series three and four may be united, giving a mean of 60.267, +.001: Wolf, Ist series _... 60.494, -4-.024 2d " -_ ________ 60.302, 4-.004 3d and 4th series ____ — _ 60.267, 4.o00 Wing _ ___ __60.244, ~-.01 2 General mean____ __ 60.27, 4-.00o This mean, the percentage of CeO2 in the anhydrous sulphate, gives Ce = 137.724; or, if O = 16, Ce - 138.039. This varies widely from the ordinarily accepted -value as determined by Buehrig. In 1875 Buehrig's t paper upon the atomic weight of cerium was issued. He first studied the sulphate, which, after eight crystallizations, still retained traces of free sulphuric acid. He found furthermore that the salt obstinately retained traces of water, which could not be wholly expelled by heat without partial decomposition of the material. * Amer. Journ. Sci. and Arts, (2,) 49, 358. I870. t Journ. fiir Prakt. Chem., I20, 222. CERIUM. 227 These sources of error probably affect all the previously cited series of experiments; although, in the case of Wolf's work, it is doubtful whether they could have influenced the atomic weight of cerium by more than one or two tenths of a unit. Buehrig also found, as Marignac had earlier shown, that upon precipitation of cerium sulphate with barium chloride the barium sulphate invariably carried down traces of cerium. Furthermore, the ceroso-ceric oxide from the filtrate always contained barium. For these reasons the sulphate was abandoned, and the atomic weight determinations of Buehrig were made with air-dried oxalate. This salt was placed in a series of platinum boats in a combustion tube behind copper oxide. It was then burned in a stream of pure, dry oxygen, and the carbonic acid and water were collected after the usual method. Ten experiments were made; in all of them the above named products were estimated, and in five analyses the resulting cerosoceric oxide was also weighed. By deducting the water found from the weight of the air-dried oxalate, the weight of the anhydrous oxalate is obtained, and the percentages of its constituents are easily determined. In weighing, the articles weighed were always counterpoised with similar materials. The following weights were found: Oxalate. Water. CO2. CeO2. 9.8541 grm. 2. i987 grm. 3.6942 grmn. 9.5368 " 2.1269 " 3.5752 " 9.2956 " 2.0735 " 3.4845 " 10.0495 " 2.2364 " 3.7704 " 10.8249 " 2.4145 4.0586 " 9.3679 " 2.0907 3.511 8 " 4.6150 grm. 9.7646 " 2.1769 " 3.6616 " 4.8133 " 9.9026 " 2.2073 3.7139 " 4.8824 " 9-9376 " 2.2170'2 3.7251 " 4.8971 " 9.5324 " 2.1267 " 3.5735 " 4.6974 " These figures give us the following percentages for CO, and CeO 2 in the anhydrous oxalate: co2. CeO2. 48.256 48.249 48.248 228 THE ATOMIC WEIGHTS. Ce 02. c2. 48.257 48.257 48.258 63-417 48.257 63-436 48.262 63.446 48.249 63.429 48.253 63-430 Mean, 48.2546, 4-.oo 63-4316, +-.0032 From percentage CO2...Ce = 141.228, -4-.025 CeO2 ___ 141.141, 4-.020 Obviously the single oxalate experiments of Jegel and of Rammelsberg would exert no appreciable influence upon these mean results. They may therefore be ignored. In combining all of these data in one general mean, we may begin as usual by tabulating our ratios: (I.) BaSO4: Ce2(SO4)3:: 100: 123.o019, 4-.113 (2.) BaSO4: CeO2:: 100: 49-360, 4-.035 (3.) BaCl2: Ce2(SO4)3:: Ioo: 91.625, 4-.oi6 (4.) AgC1: CeO2:: IOO: 40.469, ~-.0415 (5.) Percentage CeO2 from anhydrous sulphate, 60.271, 4-.00I (6.)... oxalate, 63.43I6, -.0032 (7 ) " CO2 t " 48.2546, -.ooI These ratios give us four values for the molecular weight of CeO2 and two values for Ce2(SO4)3: From (2) ___- -__ CeO2 = 172.218, 4-.I24 " (4) —--- I73.663, -.1I79 (5) _ = 169.651, 4.034 " (6) " = I 73.o68, -.033 General mean " = I171.490, -.023 From (I)____ Ce2(SO4)3 = 567.234, 4-.522 " (3) —---- " 570-375, 4- - 65 General mean_ " = 570.093, ~.1I56 Hence we have three independent values for the atomic weight of cerium, as follows: LANTHANUM. 229 From molecular weight of CeO2 -__._.Ce = 139.563, +'.024.... Ce2(SO4)3 ----- = 141.28I, -.0o83 From ratio (7,) CO2 in oxalate_______ 141.228, --.025 General mean_ - " 140.424, q-.017 Or, if 0 = 16, Ce = 140.747. Buehrig's results alone, both sets combined, give Ce = 141.198, _.020; or, if 0 = 16, Ce - 141.523. Wolf and Wing's figures alone make Ce = 137.724; or, if O- 16, Ce = 138.039. The latter result is subject to the errors pointed out by Buehrig as involved in the use of cerium sulphate; but the ceroso-ceric oxide obtained in the analyses was pure white. Buehrig's ceroso-ceric oxide, on the other hand, was yellow. In neither case was didymium present. All things considered, therefore, it is probable that the lower result is too low and the higher result too high. How near the general mean of all may be to the truth we have no evidence to show. It is clear that new determinations are needed, made with material yielding white ceroso-ceric oxide, and with avoidance of the sources of error which Buehrig pointed out. LANTHANUM. Leaving out of account the work of Mosander, and the valueless experiments of Choubine, we may consider the estimates of the atomic weight of lanthanum which are due to Hermann, Rammelsberg, Marignac, Czudnowicz, Holzmann, Zschiesche, Erk, and Cleve. From Rammelsberg * we have but one analysis..700 grm. of lanthanum sulphate gave.883 grm. of barium sulphate. Hence 100 parts of BaSO4 are equivalent to 79.276 of La2(SO4)3. *Poggend. Annal., 55, 65. 230 THE ATOMIC WEIGHTS. Marignac,* working also with the sulphate of lanthanum, employed two methods. First, the salt in solution was mixed with a slight excess of barium chloride. The resulting barium sulphate was filtered off and weighed; but, as it contained some occluded lanthanum compounds, its weight was too high. In the filtrate the excess of barium was estimated, also as sulphate. This last weight of sulphate, deducted from the total sulphate which the whole amount of barium chloride could form, gave the sulphate actually proportional to the lanthanum compound. The following weights are given: La2(S04)3. Ba C2. ist BaSO4. 2d BaSO4. 4.346 grm. 4.758 grm. 5.364 grm..II5 grm. 4.733 5.178 " 5.848 ".147 Hence we have the following quantities of La2(SO4)3 proportional to 100 parts of BaSO,. Column A is deduced from the first BaSO4 and column B from the second, after the manner above described: A. B. 8I.022 83.281 80.934 83.662 Mean, 80.978, --.030 Mean, 83.47I, 4-.I28 From A~ _ ___ La = 138.776 " B ___ ____ __ 147.474 A agrees best with other determinations, although, theoretically, it is not so good as B. Marignac's second method, described in the same paper with the foregoing experiments, consisted in mixing solutions of La2(SO4)3 with solutions of BaCI2, titrating one with the other until equilibrium was established. The method has already been described under cerium. The weighings give maxima and minima for BaCli. In another column I give La2(SO 4) proportional to 100 parts of BaCl,2 mean weights being taken for the latter: * Archives des Sci Phys. et Naturelles, (I,) I I, 29. I849. LAN'THANUM. 231 La2( S4).3 Ba C12. Ratio. 11.644 grm. 12.765 - I2.825 grm. 91.004 12.035 " 13. 95 - 13.265 " 90.968 1O.690 " I1.669 - 11.749 " 91.297 12.750 13.920- 14.000 " 91.332 Io0757 " 11.734 - I 1.814 " 91.362 12.672 " 13.8I3 - I3.893 91.475 9.246 " O.080 - IO. I6o " 91.364 10.292 " 11.204- 11.264 " 91.615 10.192 " I.III - 11.171 " 91.482 Mean, 91.322, 4-.048 Hence La- 140.484. Although not next in chronological order, some still more recent work of Marignac's* may properly be considered here. The salt studied was the sulphate of lanthanum, purified by repeated crystallizations. In two experiments the salt was calcined, and the residual oxide weighed; in two others the lanthanum was precipitated as oxalate, and converted into oxide by ignition. The following percentages are given for La2 0 57.56 ) By calcination. 57.58 57-50 ~ Ppt. as oxalate. 57-55 Mean, 57.5475, T.0115 The atomic weight determinations of Holzmannt were made by analyses of the sulphate and iodate of lanthanum, and the double nitrate of magnesium and lanthanum. In the sulphate experiments the lanthanum was first thrown down as oxalate, which, on ignition, yielded oxide. The sulphuric acid was precipitated as BaSO, in the filtrate. La2(SO4)3. La2 0.3 BaS04..9663 grm..5157 grm.. 1.1093 grm..6226 ".3323 ".7123.8669 ".4626 ".9869 " * Ann. de Chinl. et de Phys., (4,) 30, 68. 1873. t Journ. fiir Prakt. Chem., 75, 32I. 1858. 232 T'HE ATOMIC WEIGHTS. These results are best used by taking the ratio between the BaSO4, put at 100, and the La201. The figures are then as follows: 46.489 46.652 46.873 Mean, 46.671, —.075 In the analyses of the iodate the lanthanum was thrown down as oxalate, as before. The iodic acid was also estimated volumetrically, but the figures are hardly available for present discussion. The following percentages of La2 0 were found: 23-454 23.419 23.468 Mean, 23.447, 4-.0216 The formula of this salt is La2(I03)6.3H20. The double nitrate, La2(NO3 )6.3Mg(NO,3 ) 2.24H20, gave the following analytical data: Salt. I 0O. La203..5327 grm..1569 grm..0417 grm..I131 grm..5931 ".1I734 ".0467 ".1262.5662 ".1647 ".o0442." 197 ~3757 ".0297.0813 " ~3263 ".0256.0693 These weighings give the subjoined percentages of La2 03: 21.231 21.278 21.141 21.640 21.238 Mean, 21.3056, -~.058 These data of Holzmann give values for the molecular weight of La2,03 as follows: From sulphate _________La20 325.674, -4.522 " iodate......... " -- 322.419, ~4.113 " magnesian nitrate " = 324-355,!.923 LANTHANUM. 23:3 Czudnowicz * based his determination of the atomic weight of lanthanum upon one analysis of the air-dried sulphate. The salt contained 22.741 per cent. of water..598 grm. gave.272 grm. La203 and.586 grm. BaSO4. The La2 03 was found by precipitation as oxalate and ignition. The BaSO4 was thrown down from the filtrate. Reduced to the standards already adopted these data give for the percentage of La203 in the anhydrous sulphate the figure 58.668. 79.117 parts of the salt are proportional to 100 parts of BaSO4. Hermann t studied both the sulphate and the carbonate of lanthanum. From the anhydrous sulphate, by precipitation as oxalate and ignition, the following percentages of La203 were obtained: 57.690 57.663 57.6Io Mean, 57.654, --.oi6 The carbonate, dried at 1000, gave the following percentages: 68.47 La2(). 27.67 CO2. 3.86 H20. Reckoning from the ratio between CO2 and La203 the molecular weight of the latter becomes 325.896. Zschiesche's experiments consist of six analyses of lanthanum sulphate, which salt was dehydrated at 230~, and afterwards calcined. I subjoin his percentages, and in a fourth column deduce from them the percentage of La203 in the anhydrous salt: -2~' So3. La2 03. La203 in anhydrous salt. 22.629 33.470 43.909 56.745 22.562 33-306 44.132 56.964 22.730 33.200 44.070 57.034 * Journ. fiir Prakt. Chem., 80, 33. x86o. tJourn. fur Prakt. Chem., 82, 396. i86I. + Journ. fur Prakt. Chem., I04, 174. 234 THE ATOMIC WEIGH1TS. h, O. SO0. La2 03. La2,O in anhydrous salt. 22.570 33-333 44.090 56.947 22.6o0 33.160 44.240 57. I50 22.630 33.051 44-3I0 57.277 Mean, 57.021, 4-.051 Erk * found that.474 grm. of La,(SO4)3, by precipitation as oxalate and ignition, gave.2705 grm. of La2 03, or 57.068 per cent..7045 grm. of the sulphate also gave.8815 grm. of BaSO4. Hence 100 parts of BaSO4 are equivalent to 79.921 of La2 (S04 ) 3. Last of all, and probably best of all, we come to the determinations of Cleve.t Strongly calcined La203, spectroscopically pure, was dissolved in nitric acid, and then, by evaporation with sulphuric acid, converted into sulphate: I.9215 grm. La203 gave 3.3365 grm. sulphate. 57.590 per cent. 2.0570 " 3.5705 57.6I I I.6980 " 2.9445 " 57.667 2.0840 " 3.6170 " 57.617 1.9565 " 33960 " 57.612 Mean, 57.619, -.0085 From the last column, which indicates the percentage of La203 in La(SO,)3, we get, if S03 = 80, La = 139.15. We may now combine the similar means into general means, and deduce a value for the atomic weight of lanthanum. For the percentage of oxide in sulphate we have six estimates, as follows. The single experiments of Czudnowicz and of Erk are assigned the probable error and weight of a single experiment in HIermann's series: Czudnowicz _ _.___ 58.668, 4-.027 Erk _ 57.o68, 4-.027 Hermann _57.654, ~-.oi6 Zschiesche 57.02I, -.051 Marignac 57.5475, -.0 I15 Cleve _ 57.6I9, -.oo85 General mean-___-______ 57.620, -.0059 * Jenaisches' Zeitschrift, 6, 306. 187I. t K. Svenska Vet. Akad. Handlingar, Bd. 2, No. 7. 1874. LANTHANUM. 235 For the quantity of La2(SO4)1 proportional to 100 parts of BaSO4, we have five experiments, which may be given equal weight and averaged together: Marignac___ —- —. — ______ _ 8I.022 -,____,______ ----— __ 8o.934 Rammelsberg 79.276 Czudnowicz.- 79I 117 Erk 79.921 Mean, 80.054, _-.270 In all, there are seven ratios from which to calculate: (i.) Percentage of La203 in La,(SO4)3, 57.620, -.0059 (2.) BaCI2: La2(SO4)3:: IOO: 91.322, +-.o48-Marignac. (3-) BaSO4: La2(SO4)3:: Io: 80.054, 4-.270 (4.) BaSO4: La203:: Ioo: 46.67I, -+-.o75-Holzmann. (5.) Percentage of La,20 in iodate, 23.447, -4-.02I6 Holzmann. (6.) c c. magnesian nitrate, 21.3056, 4-.o58-Holzmann. (7.) a' "t carbonate, 68.47-Hermann. These ratios give five values for the molecular weight of lanthanum oxide, and two for that of the sulphate: From (2)_________La2(S04)3 = 568.488, +.320 SC CC(3) —------- " = 558.624, -4- 1.888 Generalmean, " t 568.212, 4-.316 Hence La = 140.346, 4-.160. From (I)_ LO a2 = 325.79, -4-.074 (4) __ _ ____ = 325.674, -.522 (5) --------- ---— _-" —- 322.419, -4-.113 " (6).... __ ___ " - 324-355, ~-.923 s (7) —- - 325.896,-.488 General mean ___ " -324.8Io, -4-.o6 Here the value derived from ratio (7) is given the weight of a single experiment in ratio (1.) Hence La = 138.460, +.031. Combining the two values for La, we get this final result: From La2O --- ___La = I38.460, +.03I " La2(S4), -- -- 40.346, --.I6 General mean_____ " = I38.526, ~ —.030 Or, if 0 = 16, La = 138.844. 236 THE ATOMIC WEIGHTS. Since this value is a little under and Cleve's a little over 139, the latter figure may fairly be used in all calculations involving a knowledge of the atomic weight of lanthanum. DIDYMIUM. The atomic weight of didymium has been determined by Marignac, Hermann, Zschiesche, Erk, and Cleve. Mosander's early experiments we may leave out of account. Marignac * mixed a solution of the sulphate with a slight excess of barium chloride, filtered, weighed the precipitate, and estimated the excess of barium in the filtrate by the ordinary method. The first precipitate always contained didymium, and therefore weighed too much. By deducting the weight of the second precipitate, representing the excess of the barium chloride, from the weight of barium sulphate theoretically formable, the weight of the latter proportional to the quantity of didymium salt taken was found: Di2(504)3' Ba C2. s't BaS04. 2d BaSO4. 3.633 grin. 3.902 grm. 4.412 grin..084 grm. 3.862 " 4.227 " 4.679 ".075 " 3.330 " 3.552 " 4.027 ".088 " 1.386 " 1.477 " I.68I ".OI4 These figures give us a ratio between the sulphates of didymium and barium which we may express as follows. Column A gives the Di2(SO,)3 proportional to 100 parts of BaSO4, as calculated from the first precipitate of the latter. Column B gives a similar ratio calculated with the second BaSO4 precipitate, this being deduced from the total BaSO4 which the chloride used could form: A. B. 82.344 84.685 82.539 82.626 82.692 85-545 82.451 84.425 82.247-Erk. Mean, 84.320, _+.414 Mean, 82.455, --.052 * Arch. des Sci. Phys. et Naturelles, (I,) I I, 29. 1849. DIDYMIUM. 237 To A I have added a single result of Erk's, to be described further along. It will be seen that although A is theoretically defective, its figures are much more concordant than those in B. In fact, the latter would almost vanish for the final general mean for the atomic weight of didymium: From A __- ___ ___ __.______ Di - I43.929 __ ___ _ = I50.436 In a later paper* Marignac adopts two other methods for establishing the atomic weight of didymium. The carefully dehydrated sulphate was taken, the didymium was precipitated as oxalate, and the latter, ignited, yielded oxide. The following percentages of oxide were found: 58.22 58.24 58.29 58.3I 58.29 Mean, 58.27, -4-.01 5 The chloride of didymium was also studied. As the anhydrous salt could not be obtained in an absolutely definite state, Marignac prepared neutral solutions of it and determined the ratio between didymium oxide and silver chloride. The latter compound was first precipitated in the usual way, and filtered off; the excess of silver in the filtrate was removed by hydrochloric acid, and after that the didymium was thrown down as oxalate and weighed as oxide. The subjoined weights of AgCl and DiO, were found. In a third column I give the ratio between the two compounds, putting AgC1 at 100: AgCl. Di2 03. Ratio. IO.058 grm. 3.946 grm. 39.232 5.029 " 1.960 " 38.974 5.844 " 2.276 " 38.946 Mean, 39.o5 I, +.0o6 Hence Di 1- 43.637, --.263. * Ann. d. Chim. et d. Phys., (3,) 38, 148. I853. 238 THE ATOMIC WEIGHTS. Hermann's * determination of the atomic weight of didymium rests on a single experiment with the sulphate. By precipitation as oxalate and subsequent ignition, he found that this salt yielded 58.14 per cent. of Di203. Zschiesche t also analyzed didymium sulphate, which he dehydrated at 230~, and afterwards converted into oxide by calcination. I give his percentages, and also, in a fourth column, the percentage of oxide from the anhydrous sulphate as deduced from his figures: 2 o0. So3 Di20.. Di03 in anyd. salt. 23.I9 32.97 43.83 57.070 23.0o3 32.39 44.58 57.919 23.00 32-56 44.95 58.0o6 23.547 3I-938 44-5I5 58.225 22.550 32.870 44.570 57-554 The salt used in the first experiment probably contained lanthanum. Rejecting this, the mean of the figures remaining in the fourth column is 57.926, +.094. Hence Di = 141.007. Erk,t to whom reference has already been made, estimated didymium in the sulphate by precipitation as oxalate and calcination to oxide: Di2(S04)3 Di203. Per cent. Di2 03..556 grm..323 grm. 58.094.674 ".3915 " 58.087 Hermann's single result for this percentage, 58.14, agrees more nearly with Erk's series than with any other. It may therefore be averaged in with Erk's two experiments, giving a mean of 58.107, ~.0112. Erk also obtained from.7065 grm. of sulphate.859 grm. BaSO4. This experiment has already been averaged with Marignac's earlier results. The latest determinations of the atomic weight of didymium were published by Cleve II in 1874. Strongly calcined *Journ. fiir Prakt. Chem., 82, 367. i86I. t Journ. fiir Prakt. Chem., I07, 74. t Jenaisches' Zeitschrift, 6, 306. I87I. 1[ K. Svenska Vet. Akad. Handlingar, Bd. 2, No. 8. These figures were kindly transcribed for me by Professor Delafontaine of Chicago, as I had not access to a copy of the original memoir. DIDYMIUM. 239 didymium oxide was dissolved in nitric acid, the solution was evaporated with sulphuric acid, and the weight of the resulting sulphate was ascertained. I subjoin the weighings and the percentage of Di 0 3 in Di, (SO,4) 3 Di, 03. Di2(SO4)3. Per cent. Dia 03. 2.257 grin. 3.844 grm. 58.715 I.o86 " 1.8485 " 58.750 I.1525 " I.96i5 " 58-756 1.3635" 2-.39 " 58-797 i.9655 " 3-3435" 58.786 1.528 " 2.599 " 58.792 Mean, 58.766, _-.oo87 Hence Di = 146.804. If SO1 = 80, Di = 147.021. This determination is undoubtedly the best of all, and might properly be accepted to the exclusion of the others. Still, it is worth while to combine all the figures into one general mean. For the percentage of Di203 in Di2(SO4)3 we have the following data: Marignac 58.270, 4_.o0115 Erk and Hermann.__.________ 58.107, 4-.0112 Zschiesche 57.926, -.094 Cleve ------ ____________ 58.766, 4-.0087 General mean __-_- ____ 58.45 I, _.0059 For the atomic weight of didymium we have now three independent values: From per cent. Di203 in Di2(SO4)3- ____-Di = I44.604, 4.031 Marignac's chloride analyses -,,-_- 143.637, ~-.263 Marignac's and Erk's BaSO4ratio_ " = I43.929, ~-.I89 General mean.-. ____." — I144.573, -+.0306 If 0 - 16, Di = 144.906. 240 THE ATOMIC WEIGHTS. THE YTTRIUM GROUP. The atomic weights of the metals in this group can only be said to have been determined approximately. Not only do great difficulties attend the purification of the material used for study and the separation of the earths from each other, but there have been and still are grave doubts as to the actual nature of some of the latter. The figures for scandium, yttrium, and ytterbium seem to be tolerably good; those for decipium, philippium, thulium, erbium, and terbium are little more than estimates; for samarium wve have no data whatever. All the atomic weights in this group are based upon analyses or syntheses of sulphates; and from analogy to the cerium metals all of these elements are regarded as forming sesquioxides. SCANDIUM. Cleve,* who was the first to make accurate experiments on the atomic weight of this metal, obtained the following data. 1.451 grm. of sulphate, ignited, gave.5293 grm. of Sc203..4479 grm. of Sc203, converted into sulphate, yielded 1.2255 grm. of the latter, which, upon ignition, gave.4479 grm. of Sc203. Hence, for the percentage of Sc203 in Sc2(SO,)3 we have: 36-478 36.556 36.556 Mean, 36.530 Hence, if S03 = 80, Sc = 45.044. Later and better results are those of Nilson,t who converted scandium oxide into the sulphate. I give in a third column the percentage of oxide in sulphate: * Compt. Rend., 89, 419. tCompt. Rend., 9I, i 8. THE YTTRIUM GROUP. 241 -3379 grin. Sc,O, gave.9343 grm. Sc,(S04)3. 36. i66 per cent..30I5.. 8330 36. 194.2998 ".8257 it 36. i87.3192 ".8823 " 36. I178 Mean, 36.18I, A.004 Hence Sc = 43.980, -.015; or, if 0 = 16, then Sc = 44.081. If SO, =- 80, then Sc = 44.032. These values are doubtless very nearly correct. YTTRIUM. For yttrium we need consider only the determinations of Popp, Delafontaine, Bahr and Bunsen, and Cleve. Popp* evidently worked with material not wholly free from earths of higher molecular weight than yttria. The yttrium sulphate was dehydrated at 2000; the sulphuric acid was then estimated as barium sulphate; and after the excess of barium in the filtrate had been removed, the yttrium was thrown down as oxalate, and ignited to yield oxide. The following are the weights given by Popp: Suzplhate. BaSO,. Y32 0O.,2 0. 1.1805 grm. 1.3145 grm..4742 grm..255 grm1.4295 " I-593 ".5745 " -308.8455 ".9407 ".3392 ".1825" 1.045, i. X635 ".4195 ".2258 " Eliminating water, these figures give us for the percentages of Yt,23 in Yt,(SO,), the values in column A. In column B I put the quantities of Yt203 proportional to 100 parts of BaSO: A. B. 51.237 36.075 51.226 36.064 51.I6I 36.058 51.209 36.055 Mean, 51.208, 4-.OII Mean, 36.063, 4-.003 From B, Yt = 101.880. The values in A will be combined with similar data from other experimenters. * Ann. Chem. Pharm., 13I, I79. 16 242 THE ATOMIC WEIGHTS. In 1865 Delafontaine * published some results obtained from yttrium sulphate, the yttrium being thrown down as oxalate and weighed as oxide. In the fourth column I give the percentages of Yt, 0 reckoned from the anhydrous sulphate: Suphate. Yt, o0. z o. Per cent. Yt 03..9545 grmin. 37I grm..216 grm. 50.237 2.485 ".9585 ".565 " 49.922 2. 153.827 ".4935" 49.834 Mean, 49.998, -.08I In another paper t Delafontaine gives the following percentages of Yt,O,3 in dry sulphate. The mode of estimation was the same as before: 48.23 48.09 48.37 Mean, 48.23, 4-.055 Bahr and Bunsen,J and likewise Cleve, adopted the method of converting dry yttrium oxide into anhydrous sulphate, and noting the gain in weight. Bahr and Bunsen give us the two following results. I add the usual percentage column: Yt,2 o. Yt,(S04)3. Per cent. Yt203..7266 grm. I.4737 grm. 49.304.7856 " 1.5956 " 49.235 Mean, 49.2695, 4-.0233 Cleve's 1I results are published in a joint memoir by Cleve and Hoeglund, and are as follows: * Ann. Chem. Pharm., 134, I08. t Arch. des Sci. Phys. et Nat., (2,) 25, I I9. I866. I Ann. Chem. Pharm., 137, 21. i866. 11 K. Svenska Vet. Akad. Handlingar, Bd. I, No. 8. THE YTTRIUM GROUP. 243 Yt,03. Y(S,4). f3 Per cent. YtO3. 1.4060 grm. 2.8925 grm. 48.608 1.0930 " 2.2515 " 48-545 1.4540 2.9895 " 48.637 1.3285 2.7320 " 48.627 2.3500 " 4.8330 " 48.624 2.5780 " 5.3055 " 48.591 Mean, 48.605, 4-.o096 This series is unquestionably the best of all. From it, if SO3- 80, Yt = 89.485. Combining all these data we have the subjoined general mean for the percentage of Yt,,03: Popp ---.- — __________ ____ 51.208, 4-.OII Delafontaine, ISt-_ 49.998, 4-.o8i "1 2d 48.230, -.055 Bahr and Bunsen_____ ____ 49.2695, -.0233 Cleve- ______ -_-_-_________48.605, 4-.0096 General mean_ - _ 49.637, -.0o69 Rejecting Popp _ —__-_-_ 48.705, -.0087 From the general mean of all, Yt = 97.616. From the mean after excluding Popp's work, Yt = 89.816, -+-.067; or, if O = 16, Yt = 90.023. YTTERBIUM. For ytterbium we have one very good set of determinations by Nilson.* The oxide was converted into the sulphate after the usual manner: Yb,203,. Yb2(SO4)3. Per cent. Yb,203. 1.00oo63 grm. i.6186 grm. 62.171 1.0139 " I.63I4 " 62. 149.8509 " 1.3690 " 62.I55.737I " i.i86I " 62. I45 1.0005 " 1.6099 " 62.147.8090 " 1.3022 " 62. I126 1.0059 " I.6189' 62.134 Mean, 62.147, ~-.0036 * Compt. Rend., 91, 56. i880. 244 THE ATOMIC WEIGHTS. Hence Yb = 172.761, -.038. If O- = 16, then Yb173.158. If S3 = 80, Yb = 173.016. The true number cannot be far from 173. ERBIUM. Since the earth which was formerly regarded as the oxide of this metal is now known-to be a mixture of two or three different oxides, the older determinations of its molecular weight have little more than historical interest. Nevertl-eless the work done by several investigators may properly be cited, since it sheds some light upon certain important problems. First, Delafontaine's * early investigations may be considered. A sulphate, regarded as erbium sulphate, gave the following data. An oxalate was thrown down from it, which, upon ignition, gave oxide. The percentages in the fourth column refer to the anhydrous sulphate. In the last experiment water was not estimated, and I assume for its water the mean percentage of the four preceding experiments: Suphate. Er2 03. H2 0. Per cent. Er2 03..827 grm. -353 grm..177 grm. 54.308 I.0485 ".4475 ".226 " 54-407.803 ".3415 ".I71 " 54.035 1.232 ".523 ".264 54.028 1. 1505.495 " 54.76o Mean, 54.308, ~4-.095I Bahr and Bunsen t give a series of results, representing successive purifications of the earth which was studied. The final result, obtained by the conversion of oxide into sulphate, was as follows:.7870 grm. oxide gave 1.2765 grm. sulphate. 6i.653 per cent. oxide. Hoeglund,$ following the method of Bahr and Bunsen, secured these results: * Ann. Chem. Pharm., 134, I08. 1865. t Ann. Chem. Pharm., 137, 21. I866. IK. Svenska Vet. Akad. Handlingar, Bd. I, No. 6. THE YTTRIUM GROUP. 245 Er2 03. Er,(SO)3. Per cent. Er. OQ. 1.8760 grm. 3.0360 grm. 61.792 1.7990 " 2.9100 " 61.821 2.8410 " 4-5935 " 6i.848 1.2850 " 2.0775 " 61.853 1.1300 " i.827 " 61.850.8475 " 1.370 " 6i.86I Mean, 61.8375, —.0oo63 Humpidge and Burney * give data as follows: 1.9596 grm. Er2(SO4)3 gave 1.2147 grm. Er203. 61.987 per cent. 1.9011 " I. I781 " 61.965 " Mean, 6I.976, 4-.0074 Combining all four series we get the subjoined general mean for the percentage of oxide in sulphate. Bahr and Bunsen's single experiment is given the probable error of one experiment in Hoeglund's series: Delafontaine___________. 54.308, -4.0915 Bahr and Bunsen-__- 61.653, +-.0178 Hoeglund 61.8375, -.0063 Humpidge and Burney - ------- 61.976, 4-.0074 General mean-_ __ 6i.86o, -.0046 Rejecting the first..... 61.88o, 4-.0046 From the mean of all, Er = 170.379, +.082; or, if O = 16, Er - 170.770. From Bahr and Bunsen's determination, Er = 168.683; and from Humpidge and Burney's highest, Er - 171.428. The foregoing data were all published before the composite nature of the supposed erbia was fully recognized. It will be seen, however, that three sets of results were fairly comparable, while Delafontaine evidently studied an earth widely different from that investigated by the others. Since the discovery of ytterbium, some light has been thrown on the matter. The old erbia is a mixture of at least three earths, to one of which, a rose-colored body, the name erbia is now restricted. For the atomic weight of the true erbium * Journ. Chem. Society, Feb., 1879, p. I I6. 246 THE ATOMIC WEIGHTS. Cleve * gives three values, but without data concerning weighings or methods. Doubtless the oxide was converted into sulphate, and the calculations were made with SO3 80: I66.oo i66.21 I66.25 Mean, I66.153 With SO, - 79.874, this becomes 165.891, and if only O = 16, 166.273. These figures are undoubtedly the nearest yet reached to the true value. According to Thalen,t who reasons from spectroscopic evidence, the erbium of Hoeglund was largely ytterbium. TERBIUM, SAMARIUM, PHILIPPIUM, DECIPIUM, THULIUM, HOLMIUM, AND SORET S EARTH X. Concerning these substances, real or alleged, the data are exceedingly vague. For phillippium Delafontainel gives an atomic weight approximating to 123 or 125, and in the same memoir decipium is put at 171. It seems probable that philippium may be identical with Cleve's holmium and the metal of Soret's earth X, while decipium comes near Cleve's thulium, for which the discoverer gives a value of about 170.7.11 If decipium and thulium are identical, or if either proves to be erbium or ytterbium contaminated with the other, then we shall have a triad of metals with atomic weights ranging from Er = 166 to Yb = 173, strikingly parallel with lanthanum, cerium, and didymium. If we take the natural arrangement of the elements as tabulated after Mendelejeff's plan, somewhat modified in Roscoe and Schorlemmer's " Treatise on Chemistry,~ we find that such a triad should exist, and, furthermore, that another similar * Compt. Rend., 91, 382. t Poggend. Beibllitter, 5, I22. I88I. 4 Arch. des Sci. Phys. et Nat., Mars, I88o. || Compt. Rend., 9I, 329. I88o. Q Vol. 2, Part 2, p. 507. COLUMBIUM. 247 group ought to lie between indium and tin. The latter triad should have atomic weights ranging from 114 to 117; and here possibly, or else forming a triad with yttrium, the other metals of this group may lie. COLUMBIUM.* The atomic weight of this metal has been determined by Rose, Hermann, Blomstrand, and Marignac. Rose t analyzed a compound which he supposed to be chloride, but which, according to Rammelsberg,j must have been nearly pure oxychloride. If it was chloride, then the widely varying results give approximately Cb = 122; if it was oxychloride, the value becomes nearly 94. If it was chloride, it was doubtless contaminated with tantalum compounds. Hermann's ll results seem to have no present value, and as for Blomstrand's,~ I am not able to get at a copy of his original memoir. The results of the latter chemist are thus summed up in Becker's "Digest." Three chlorine estimations in the pentachloride give, in mean, Cb - 96.67. Eleven weighings of columbic acid from the same comnpound make Cb- 96.16. Other experiments on sodium columbate lead Blomstrand to regard 95 as the most probable value. Marignac ~ made about twenty analyses of the potassium fluoxycolumbate, CbOF3.2KF.HO. 100 parts of this salt give the following percentages: Cb205 -____Extremes 44.I5 to 44.60 Mean, 44.36 K2SO4.... " 57.60 " 58.05 H20 ------- 575 " 5.98 F. ____ " 30.62 " 32.22 * This name has priority over the more generally accepted "niobium," and therefore deserves preference. t Poggend. Annal., Io04, 439-. 858. t Poggend. Annal., I36, 353. I869. I[Journ. fiir Prakt. Chem., 68, 73. I856. Q Acta Univ. Lund, i864. ~ Archives des Sci. Phys. et Nat., (2,) 23, 258. 1865. 248 THE ATOMIC WEIGHTS. From the mean percentage of Cb,05, Cb = 93.217. If O = 16, this becomes 93.431. From the mean between the extremes given for KSO4, Cb - 93.812. If 0 - 16, this becomes 94.027. As Deville and Troost's * results for the vapor density of the chloride and oxychloride agree fairly well with Cb = 94, we may adopt this value as approximately correct. TANTALUM. The results obtained for the atomic weight of this metal by Berzelius,t Rose,T and Hermann 11 may be fairly left out of account as valueless. These chemists could not have worked with pure preparations, and their data are sufficiently summed up in Becker's " Digest." Marignac~ made four analyses of a pure potassium fluotantalate, and four more experiments upon the ammonium salt. The potassium compound, KI TaF7 was treated with sulphuric acid, and the mixture was then evaporated to dryness. The potassium sulphate was then dissolved out by water, while the residue was ignited and weighed as Ta 05. 100 parts of the salt gave the following quantities of Ta2 0 and KI2SO: Ta2 05. KSO4,. 56.50 44-37 56.75 44-35 56-55 44.22 56.56 44.24 Mean, 56.59, +-.037 Mean, 44.295, 4-.026 * Comptes Rend., 56, 891. 1863. t Poggend. Annal., 4, 14. 1825. Lehrbuch, 3, I209. $ Poggend. Annal., 99, 80. 1856. 11 Journ. fur Prakt. Chem., 70, 193. I857. g Archives des Sci. Phys. et Nat., 26, 89, serie 2. I866. PLATINUM. 249 From these figures, 100 parts of K2SO4 correspond to the subjoined quantities of Ta2 0: I27-338 127.960 128.178 127.848 Mean, 127.831, -4.120 The ammonium salt, (NH4)2TaF7, ignited with sulphuric acid, gave these percentages of Ta 05. The figures are corrected for a trace of K2SO4 which was always present: 63.08 63.24 63.27 63.42 Mean, 63.25, 4-.047 Hence we have four values for Ta: From potassium salt, per cent. Ta2O5 -___Ta = 183.033, 4-.343..... " K2SO4..... "= I81.619, q-.242 K2S04: Ta205 __ — "= I82.36I, ~.411 " ammonium salt, per cent. Ta205.- -- I82.149, 4-.456 General mean_- "-I82. I44, -. I66 Or, if 0 = 16, Ta = 182.562. If we assume K = 39, 0 = 16, F 19, S = 32, and N= 14; the percentage of K2SOQ from K2TaF7 gives Ta = 181.912; and the analyses of the ammonium salt make Ta = 182.020. Evidently, 182 is not far from the true value. PLATINUM. For this metal we have to consider only experiments by Berzelius, by Andrews, and by Seubert. In an early paper Berzelius* reduced platinous chloride, and found it to contain 73.3 per cent. of platinum. Hence, Pt = 194.204, a * Poggend. Annal., 8, 177. I826. 250 THE ATOMIC WEIGHTS. value very near that obtained most recently by Seubert. In his later investigations, Berzelius * studied the potassium chloroplatinate, K2PtC16. 6.981 parts of this salt, ignited in hydrogen, lost 2.024 of chlorine. The residue consisted of 2.822 platinum, and 2.135 potassium chloride. From these data we may calculate the atomic weight of platinum in four ways: Ist. From loss of C1 upon ignition -- Pt 1 I97.722 2d. " weight of Pt in residue_...~. " - I96.942 3d. " " KC1 " _ -____- _ "=- I96.2I5 4th. " ratio between KC1 and Pt __ — I96.652 The last of these values is undoubtedly the most reliable, since it involves no errors due to the possible presence of moisture in the salt analyzed. If O- 16, the value becomes Pt - 197.104. The work done by Andrews t is even less satisfactory than the foregoing, for the reason that its full details seem never to have been published. Alldrews dried potassium chloroplatinate at 1050, and then decomposed i.t by means of zinc and water. The excess of zinc having been dissolved by treatment with acetic and nitric acids, the platinum was collected upon a filter and weighed, while the chlorine in the filtrate was estimated by Pelouze's method. Three determinations gave as follows for the atomic weight of platinum: I97.86 197.68 198. I2 Mean, 197.887 If we assume that these values were calculated with K - 39 and Cl - 35.5, the mean, corrected by our later figures for these elements, becomes Pt = 197.382. If O = 16, this becomes Pt = 197.836. Unfortunately, Andrews does not, in his brief note upon the subject, indicate the manner by which his calculations were made. * Poggend. Annal., 13, 468. 1828. t British Association Report, I852. Chem. Gazette, Io, 380. PLATINUM. 251 Latest of all we have to consider the experiments of Seubert.* This chemist prepared very pure chloroplatinates of ammonium and potassium, and from their composition deduced the atomic weight of the metal under consideration. The ammonium salt, (NH,)2 PtCl6 was analyzed by heating in a stream of hydrogen, expelling the excess of that gas by a current of carbon dioxide, and weighing the residual metal. In three experiments the hydrochloric acid formed during such a reduction was collected in an absorption apparatus, and estimated by precipitation as silver chloride. Three series of results are given for the percentage of platinum in this salt, together with another single result which may be considered alone. Here are the figures: Series I. Series II. Series III. 43-957 43.871 43.990 43-948 43.876 43.986 43.960 43.872 44.001 43.946 43.88I 44.020 43-963 43.875 43.994 43.96I 43.879 43.996 44.004 Mean, 43.956, 4-.002 Mean, 43.876, -.ooI 44.026 43.998 Mean, 44.001, 4-.003 These series represent three preparations. The additional single experiment above referred to was made with material belonging to series II, but recrystallized from water. This salt gave 43.955 per cent. of platinum, a figure to which we may assign the probable error of one experiment in the first series. Combining, we get the subjoined general mean percentage of Pt in (NH4)2PtC16: Series I 43956, --.002 " II-___ ______ __ 43.876, 4-.ooI " III — _ _ ____ 44.001, --.003 Extra experiment____ _ _ 43-955, ~ —.004 General mean-____-___ 43.907, 4-.0009 *Ber. der Deutsch. Chem. Gesell., I4, 865. 188I. 252 THE ATOMIC WEIGHTS. Hence Pt = 194.314, ~.078. If N = 14, and C1 -= 35.5, then Pt = 194.906. Calculating with Stas' values for N and C1, Seubert gets from the four results combined above, the following figures for Pt, respectively: 194.685, 194.039, 195.034, 194.665. For the chlorine estimations in the ammonium salt the subjoined weighings are given: Salt. Pt. AgCl. 2.7054 grm. 1.1871 grm. 5.2226 grm. 2.2748 ".9958 " 4.3758" 3.0822 " 1.356i " 5.9496, Hence 100 parts of AgC1 correspond to the following quantities of salt: 51.802 5 1.986 51.805 Mean, 51.864, -4-.041 Hence, calculating directly from the ratio between 6AgC1 and (NH4)2PtC16, Pt = 196.871, _~+.363. Seubert himself reckons the percentage of chlorine from the weight of silver chloride, and then calculates the ratio between C16 and Pt. He thus finds, with Stas' value for Cl, Pt -195.330. The potassium salt, KPtC16, was also analyzed by ignition in hydrogen, treatment with water, and weighing both the platinum and the potassium chloride. These percentages were found: Pt. XC1. 40o. 9 30.706 40. 120 30.728 40.076 30.698 40.070 30.666 40. o107 30.700 40. 120 30.627 40.114 30.7Io 40. 130 30.621 Mean 40.Io7, ~.005 Mean, 30.682, 4-.009 From the first column- -_._ Pt - I94.370, --.o68 " second" -__ — " = i94.645, 4-.213 PLATINUM. 253 If K = 39, and Cl = 35.5, the first column gives Pt 194.933. Seubert, from the percentage of platinum, gets Pt - 194.392; and from the ratio 2KCl: Pt he finds Pt - 194.494. As with the ammonium salt, three experiments were made upon the potassium compound to determine the amount of chlorine lost upon reduction in hydrogen. I cite the weighings, and add in a fourth column the quantity of K2PtCl1 proportional to 100 parts of AgCl. This AgC1 represents but four atoms of the chlorine: Salt. Pt. AgCl. Ratio. 6.777I grm. 2.7158 grm. 7.9725 grm. 85.oo6 3.5834 " 1.4372 " 4.2270 " 84.774 4.4139 " I.7713 " 5.2144 " 84.648 Mean, 84.809, 4-.071 Hence Pt = 195.002, 4.415. If K = 39, Ag = 108, and C1 = 35.5, then Pt = 194.955. Seubert, calculating the percentage of chlorine and thence the ratio C14: Pt, gets Pt = 194.631. Combining all the values we have the following result for the atomic weight of platinum: i. From per cent. Pt in (NH4)2PtC6 -....Pt = I94.314, -4-.078 2. " 6AgCl: (NH,)2PtC16 ratio......."= I96.871, ~.363 3. " per cent. Pt in K2PtC16.____ " I94.370, __.o68 4. " " KC1 " -.__ = I94.645, -.213 5. " 4AgCl: K2PtC16 ratio -_-__-_' = 195.002, ~4-.415 General mean1__ " =94.415, -4-.049 Or, if O = 16, Pt = 194.867. Seubert, taking the arithmetical mean of his eight values, gets Pt = 194.620. He regards, however, those results as best which are dependent upon the percentage of platinum in the ammonium salt, and upon the complete analysis of the potassium compound. These give him a mean of Pt = 194.461, which, if corrected by reduction to a vacuum standard, becomes Pt = 194.34. In will be noticed that three of the ratios, calculated with 254 THE ATOMIC WEIGHTS. K = 39, N = 14, Ag = 108, and Cl = 35.5, give nearly Pt = 195, namely: I94.906 I94.933 194-955 The general mean of all, if O -- 16, gives Pt = 194.867. Hence, for all practical calculations, the value 195 may be safely employed. OSMIUM. The atomic weight of this metal has been determined by Berzelius and by Fremy. Berzelius* analyzed potassium osmichloride, igniting it in hydrogen like the corresponding platinum salt. 1.3165 grammes lost.3805 of chlorine, and the residue consisted of.401 grm. of potassium chloride, with.535 grm. of osmium. Calculating only from the ratio between the Os and the KC1, we have, Os = 198.494; or, if 0 = 16, Os - 198.951. Fremy's determination t is based upon the composition of osmium tetroxide. No details as to weighings or methods are given; barely the final result is stated. This, if O 15.9633, is Os = 199.190. If O = 16, Os = 199.648. Berzelius' work is evidently entitled to preference, although neither determination is in any sense equal to the present requirements of chemical science. The values given are doubtless several units too high. IRIDIUM. The only early determination of the atomic weight of iridium was made by Berzelius,t who analyzed potassium iridichloride by the same method employed with the platinum and the osmium salts. The result found from a single * Poggend. Annal., 13, 530. I828. t Compt. Rend., I9, 468. Journ. fiir Prakt. Chem., 33, 410. I844. I Poggend. Annal., 13, 435. 1828. IRIDIUM. 255 analysis was not far from Ir = 196.7. This is now known to be too high. I have not, therefore, thought it worth while to recalculate Berzelius' figures, but give his estimation as it is stated in Roscoe and Schorlemmer's " Treatise on Chemistry." In 1878 the matter was taken up by Seubert,* who had at his disposal 150 grammes of pure iridium. From this he prepared the iridichlorides of ammonium and potassium, (NH,4)2IrCl6 and KIrCl0, which salts were made the basis of his determinations. The potassium salt was dried by gentle heating in a stream of dry chlorine. Upon ignition of the ammonium salt in hydrogen, metallic iridium was left behind in white coherent lamine. The percentages of metal found in seven estimations were as follows: 43-742 43-725 43-745 43-739 43.726 43-739 43-705 Mean, 43.732, _.0035 The potassium salt was also analyzed by decomposition in hydrogen with special precautions. In the residue the iridium and the potassium chloride were separated after the usual method, and both were estimated. Eight analyses gave the following results, expressed in percentages: Ir. 2KC1. C/4. 39.88I 30.829 29.290 39.890 30.842 29.277 39.868 30.813 29.300 39.876 30.835 29.289 39.877 30.825 29.287 39.879 30.8 1 29.310 39.882 30.814 29.285 39.883 30.792 29.288 Mean, 39.880, 4-.005 30.820, ~-.0037 29.291, 4-.0024 *Ber. d. Deutsch. Chem. Gesell., II, 1767. 256 THE ATOMIC WEIGHTS. From these data several values for the atomic weight of iridium may be calculated: From per cent. Ir in (NH4)2IrCl1,J _.__ Ir - I92.951, __.o64 K2IrC16-_ __ "= I192.536, ~.o6o " KC1 in " __ _- 192.474, 4-. I I C14 in " ~_..,,__ _ _ 192.757, --.148 General mean _-= __ 1" i92.702, 4-.039 If 0 - 16, this becomes Ir - 193.145. In the potassium salt, instead of calculating from the percentages directly, we may reckon upon the ratios between Ir and Cl4, and between Ir and 2KCl: From Ir: C14 ratio__ ___J __ _ Ir - I92.626, ~-.o8I J Ir: 2KCL ratio_ __ ___ __ 192.514, -.044 General mean___ __ ___ 192.539, 4-.039 Or, if 0 16, Ir = 192.982. Again, we may combine this mean with the value derived from the ammonium iridichloride, and so estimate the relative importance of the latter: From K2IrCl- _Ir I92.539, -.039, (NH4)2IrC6 __ __ __ __ _ _92.95 I, -.o64 General mean-_ __, --- 192.651, 4.033 If 0 = 16, this becomes Ir = 193.094. We may assume, then, from all the facts before us, that if O - 16, the atomic weight of iridium varies from the even number 193 only within the limits of experimental error. PALLADIUM. The atomic weight of palladium has been studied by BerzeIius and by Quintus Icilius. In an early paper Berzelius* found that 100 parts of the metal united with 28.15 of sulphur. Hence Pd = 113.63, a result which is unquestionably far too high. *Poggend. Annal., 8, I77. 1826. PALLADIUM. 257 In a later paper* Berzelius published two analyses of -potassium palladiochloride, KI2PdCl4. The salt was decomposed by ignition in hydrogen, as was the case with the double chlorides of potassium with platinum, osmium, and iridium. Reducing his results to percentages, we get the following composition for the substance in question: Pd. 2KC/. Cl2. 32.726 46.044 2I. 229 32.655 45-74I 21.604 Mean, 32.690 45.892 21.416 From these percentages, calculating directly, very discordant results are obtained: From percentage of metal ______Pd I06.6I2 KC1 _ ___ 04.674 C12, (loss) " = IIO.796 Obviously, the only way to get satisfactory figures is to calculate from the ratio between the Pd and 2KCl. Doing this, we get, Pd - 105.737; or, if 0 = 16, Pd = 105.981. This last value varies so slightly from the even number 106 that the latter may be safely used for all purposes of chemical calculation. The determination made by Quintus Icilius* need be given only for the sake of completeness. He ignited potassium palladichloride in hydrogen, and found the following amounts of residue. His weights are here recalculated into percentages: 64.708 64.965 64.781 Mean, 64.818 From this mean, Pd = 111.879. Upon looking at the values deduced from Berzeiius' figures, it will be seen that * Poggend. Annal., 13, 454. 1828. t " Die Atomgewichte vom Pd, K, C1, Ag, C, und H, nach der Methode der kleinsten Quadrate berechnet." Inaug. Diss. G6ttingen, I847. Contains no other original analyses. 17 258 THE ATOMIC VWEIGHTS. the highest, 110.796, is calculated from the chlorine lost upon igniting the palladiochloride. The same kind of error which vitiates that result probably affects also these data drawn from the palladiochloride. RHODIUM. Berzelius* determined the atomic weight of this metal by the analysis of sodium and potassium rhodiochlorides, Na3RhCl6, and K2RhC1,. The latter salt was dried by heating in chlorine. The compounds were analyzed by reduction in hydrogen, after the usual manner. Reduced to percentages the analyses come out as follows: In Na3RhWCe6. Rh. 3Na C1. C4a. 26.959 45.853 27.189 27.229 45.301 27.470 27.616 Mean, 27.094 45-577 27.425 In K2RhCI4. Rh. 2KCI. C13. 28.989 41.450 29.56i From the analyses of the sodium salt we get the following values for Rh: From per cent. of metal Rh = 104.507... NaCl _.__. " I02.980.... C13 _,,_ _ 105.696 " ratio between C13 and Rh __ " I104.829.. NaCL __ ". 104.093 These are discordant figures, and indicate some doubt as to purity of material. The last value is fairly good, however, and is confirmed by results from the potassium compound: *Poggend. Annal., 13, 435. I828. RUTHENIUM. 259 From per cent. of metal -_.........Rh - 0Io4.54.cc. KC14_ "- I04.46.... C1a___,,_ " I04.065 " Rh: C13 ratio ___.___ -_ " 1 I04.o57 " Rh: KC1 ratio 1_0.___. __ " - Io4.o05 Mean- ______ _______ " = -o104.055 If O - 16, this becomes Rh = 104.285. RUTHENIUM. The atomic weight of this metal has been determined only by Claus.* Although he employed several methods, the only results worthy of present notice come from the analysis of potassium rutheniochloride, KRuCl5. The salt was dried by heating to 2000 in chlorine gas, but even thei retained a trace of water. The percentage results of analysis are as follows: Ru. 2KC1. CI4. 28.96 40.80 30.24 28.48 41.39 30.22 28.91 41.o8 30.04 Mean, 28.78 41.09 30. I7 Reckoning directly from the percentages we get the following discordant values for Ru: From percentage of metal ___...._____.Ru = 103.016.. " KC1 -______ "- = 107.1 90 ". C13,,_ ___ = 96.854 Obviously, the best result is to be obtained from the ratio between Ru and 2KC1. This gives Ru = 104.217; or, if O = 16, Ru = 104.457. But little weight can be attached to this determination. Journ. fiir Prakt. Chem., 34, 435. I845. APPENDIX. ON DUMAS' CORRECTION AND PROUT'S HYPOTHESIS. In the year 1815 Prout put forth his famous hypothesis that the atomic weights of all the elements were multiples of that of hydrogen. His views were adopted by many chemists, but opposed by others; among them Berzelius and Turner; and down to the present day " Prout's Law" has been the subject of earnest controversy. Of course the fact was early recognized that in its original form the hypothesis could not stand, and accordingly it was modified by Dumas in such manner that half and quarter multiples of the atomic weight of hydrogen were considered as well as the whole numbers. But of late years Prout's hypothesis, even with its elastic modification, has been in disfavor. Only a few chemists still clung to it as the representative of a veritable law. The researches of Stas were especially directed towards ascertaining its truth or falsity; and his results, as well as those obtained by Marignac, were such as to lead most chemists to the belief that it had been forever overthrown. The atomic weights determined by Stas agreed neither with whole, half, nor quarter multiples of that of hydrogen, and the variations seemed to be wholly outside the range of recognizable experimental errors. In 1878, however, a probable source of error in some of Stas' researches was pointed out by Dumas.* Many of Stas' ratios had involved the use of pure metallic silver, which had been fused under a cover of borax containing a little *Ann. Chim. Phys., (5s.,) I4, 289. (261) 262 THE ATOMIC WEIGHTS. nitre. Such silver Dumas heated to redness in a SprengeI vacuum, and found that it gave up weighable quantities of oxygen, which had been absorbed by the metal when in the melted state. In one experiment a kilogramme of silver gave 82 milligrammes of occluded gas, and in three other cases 226,140, and 249 milligrammes respectively were found. In other words, the silver which had been considered pure by Stas and others, was really not pure, and a correction became necessary in nearly all series of atomic weight determinations. The amount of this correction, which I think may hereafter be appropriately designated as "Dumas' correction," will naturally vary in different cases, and in no particular case can we tell, without actual examination of the silver employed, exactly how great it should be. We may, however, assume that all the metallic silver heretofore used in establishing atomic weight ratios was subject to it; and, reckoning from the largest error indicated in the experiments of Dumas, namely, 249 milligrammes of oxygen in the kilogramme of metal, we may ascertain its tendency with reference to Prout's law. In the chapter upon the atomic weights of silver, chlorine, bromine, iodine, potassium, sodium, and sulphur, twenty ratios are given, of which nine are subject to Dumas' correction. Applying it as suggested above, we get the following results. The values previously found and given in the chapter just quoted, we may designate as uncorrected. For convenience in future reference I assume that O - 16: Uncorrected. Corrected. Dlfference. Silver__ __ _ 107.923 107.896 -.027 Chlorine ______ 35.451 35-478 +.027 Bromine _____ -79.951 79.978 +.027 Iodine_ - ____ 126.848 I26.875 +.027 Potassium ___ 39. 109 39.083 -.026 Sodium _23.051 23.024 -.027 Sulphur 32.058 32.058 The result of the correction, it will be seen, is generally favorable to Prout's hypothesis. Of the seven elements, APPENDIX. 263 under consideration, one has its atomic weight unaffected, one is rendered less in accord with the hypothesis, and five approximate more closely than before to even multiples or multiples half of hydrogen. In the later chapters of this work the effect of Dumas' correction is generally less striking. One general statement, however, may be made concerning it. Whenever the atomic weight of a metal is calculated from the ratio between its haloid salts and metallic silver, the total effect of Dumas' correction, including the above corrections for the halogens themselves, will be to lower the final result. This point will be further considered presently. Only chlorine, bromine, and iodine have their atomic weights raised by the correction. In view of Dumas' correction the question naturally arises as to how far other metals, used in atomic weight researches, may occlude gaseous impurities. For example, when the atomic weight of oxygen is fixed by the synthesis of water over copper oxide, may not the copper occlude appreciable quantities of the hydrogen in which it cools? If it does, then the apparent weight of metallic copper would be too high, and the atomic weight of oxygen would come out too low. Such an error might possibly account for the difference between 16 and 15.9633 in the atomic weight of oxygen, and it would also increase the atomic weight of copper as determined by the same process. At all events, every metal of which the atomic weight has been determined by the reduction of its compounds in hydrogen, ought to be scrupulously investigated with reference to the possible occlusion of gaseous impurities. With all of these metals the effect of such impurities would be to render the apparent atomic weights decidedly too high. Although every series of atomic weight determinations must be considered by itself, and weighed on its own merits, it may not be out of place for me just here to point out two general sources of error in addition to the one we have been considering. First, every value after oxygen, with one or two partial exceptions, involves whatever error may attach 264 THE ATOMIC WEIGHTS. to the atomic weight of oxygen. If the latter be 16, instead of 15.9633, this error in some instances becomes multiplied to a large fraction of a unit, as the subjoined example will show. If 0 - I6, the atomic weight of uranium 239.030 If 0 15.9633, " = 238.482 Difference _-_ _ -0____ _ _ o. 548 Other similar errors are repeated continually. The value assigned to any element is necessarily affected by whatever errors may attach to the atomic weights of those other elements through whose medium it is compared with the standard, hydrogen. Thus, the atomic weight of carbon depends upon that of oxygen; calcium depends upon both carbon and oxygen; and fluorine, as determined from calcium fluoride, involves the foregoing elements, together with sulphur, silver, and chlorine. Since, however, some atomic weights'are affected by plus errors and others by minus errors, there is a fortunate tendency to compensation of errors in cases like that of fluorine, and, in reality, better results are obtained than considerations such as these would lead us to look for. Another general source of error is to be found in the fact that some of the weighings involved in our discussions had been reduced to absolute standards, while others were merely uncorrected weighings in air. The errors thus introduced into the work are doubtless small, but still they ought not to be absolutely ignored. Now, having considered the larger classes of errors, we may properly pass on to a comparison of our atomic weights with reference to Prout's hypothesis. In order to facilitate work, I have tabulated the figures in two columns, one giving atomic weights referred to hydrogen as unity, the other based upon the standard of oxygen as exactly sixteen. Such imperfectly known elements as decipium, philippium, samarium, terbium, and thulium are not included. APPENDIX. 265 TABLE OF ATOMIC WEIGHTS. H- I. O- I6. i Remarks. Aluminume --- 27.009, -.003 27.075 Antimony _ — 119.955, 4-.036 120.231 Cooke's and Schneider's data. Arsenic _ —--- 74-918, 4-.o6 75.o9o Barium - I136.763, 4-.031 I37.007 Bismuth —..__ 207.523, 4-.082 208.001 From Schneider's data. Boron -- o.94I, -.023 10.966 Bromine.... — 79.768, —.o19 79.951 Cadmium__ —__ 111.835, -4-.024 112.092 Caesium - _ — 1 I32.583, 4-.024 132.918 Calcium ---- 39.990, 4-.010 40.082 Carbon _-...___. 11.9736, __+.0028 12.0011 Cerium.. —... 140.424, 4-.017 140. 747 Buehrig's data give 141.523.. (O = I6.) Chlorine 35.370, 4- o014 35.451 Chromium_. —. 52.009, 4-.025 52.129 From Siewert's data. Cobalt _-__. 58.887, 4-.oo8 59.023 Columbium _.. 93.812 94.027 From one ratio only. Copper-_._ —_ 63.173, — 011 63.318 Didymium_ 144.573, -4-03 144.906 Cleve's data give 147.021. (S03 = 80.) Erbium _... —. I65.89I I66.273 From Cleve's data only. Fluorine ------ 18.984, 4-.0065 19.027 Gallium'-_.-.. 68.854 68.963 Imperfectly determined. Glucinum __ 9.o85, --.o055 9. io6 Nilson and Pettersson's data. Gold -- I96.I55, --.o095 96.606 Hydrogen _._ 1I.0000 1.0023 Indium _ - I113.398, ~.047 113.659 Iodine........ I26-557, +.022 I26.848 Iridium ____ I192.65I, -.033 193.094 Seubert's data. Iron _ — 55-913, 4.012 56.042 Lanthanum 138.526, -.030 138.844 Lead _ __.. 206.471, 4-.021 206.946 Lithium_...... 7.0073, -.007 7.0235 Magnesium __ 23.959, -.005 24.014 Marchand and Scheerer's data. Manganese __. 53.906, +-.012 54.029 Schneider and Rawack's data. Mercury___ I199.712, -.042 200.171 Molybdenum __ 95-527,.05I 95-747 Nickel __.._.57.928, 4-.022 58.o62 Schneider, Sommaruga. and Lee. Nitrogen 14.0210, +-.0035 14.029 Osmium_ -— __ I198.494 I98.95I Very doubtful. Oxygen ___ —-- 15.9633, 4-.0035 i6.ooo Palladium _-_- I105-737 105.981 Badly determined. Phosphorus._.. 30.958, 4-.007 3I.029 Platinum _ —-- I194.415, ~.049 194.867 Seubert's data. Potassium _- __ 39.019, 4-.012 39. IO9 Rhodium — ___ 104.055 I04.285 Badly determined. Rubidium.... 85.25I, -.018 85.529 Ruthenium 104.217. 04.457 Badly determined. Scandium 43.980, -.o15 44.081 Selenium.____ 78.797, -.011 78-978 266 THE ATOMIC WEIGHTS. TABLE OF ATOMIC WEIGHTS-CONTINUED. H - I. O- - i6. Remarks. Silicon_... 28.195, -.o66 28.260 Very badly determined. Silver ---— __. I07.675, +-.oo96 I07.923 Sodium _ —---— 22.998, -=-.oII 23.051 Strontium 87-374, +-.032 87.575 Sulphur -_-_-_ 31.984, 4-.012 32.058 Tantalum _ 182.I44, +.I66 I82.562 Tellurium 127.960, 4-.034 128.254 Imperfectly determined. Thallium — _ — 203.715, -.o365 204.183 Crookes' data. Thorium__ __ 233.414, +.073 233.951 Tin _..___ _ I 117.698, +-.040 11I 7.968 Titanium..... 49.846, -.o64 49.961 Imperfectly determined. Tungsten- ____ 183.610, -.032 I 84.32 Uranium _-___- 238.482, 4-.082 239.0J0 Vanadium __... 51.256, +-.024 51.373 Ytterbium 172.76I, -.038 173. I58 If S03 -- 8o, Yb — 173.0oi6. Yttrium ------- 89.81 6, 4-.o67 90.023 Doubtful. Zinc __-__ 64.9045, +.019 65.o054 Axel Erdmann's data. Zirconium __ 89.367, ~-.037 89.573 Doubtful. At the close of his admirable paper on the atomic weight of aluminum Mallet makes substantially the following argument in favor of Prouft's hypothesis. Citing the atomic weights of eighteen elements which he considers well determined, he shows that ten of them have values falling within one-tenth of a unit of whole numbers. Now, what is the mathematical probability that this close approximation to conformity with Prout's law, in ten cases out of eighteen, is purely accidental, as those chemists who reject the hypothesis seem to hold? Working this problem out, Mallet finds the probability in favor of mere coincidence to be in thes ratio of 1: 1097.8, and hence he concludes that Prout's views are still worthy of respectful consideration. Applying Mallet's reasoning to the table of atomic weights now before us, we find that in the first column, when H - 1, twenty-five elements out of sixty-six have values falling within the limits of one-tenth of a unit variation from whole numbers. But many of the figures which fall without this limit involve the variation of oxygen multiplied many times over. We must therefore study the second column, which assumes that the atomic weight of oxygen is exactly six APPENDIX. 267 teen. Here we have forty elements falling within the limit of variation assigned by Mallet, and twenty-six falling without. The variations we may properly study in some detail. Taking first the elements whose atomic weights vary from even multiples of unity by less than a tenth of a unit, we have to consider the following: aluminum, arsenic, barium, bismuth, boron, bromine, cadmium, caesium, calcium, carbon, cobalt, columbium, didymium, fluorine, gallium, hydrogen, iridium, iron, lead, lithium, magnesium, manganese, nickel, nitrogen, osmium, oxygen, palladium, phosphorus, scandiunl, selenium, silver, sodium, sulphur, thorium, tin, titaniumn, tungsten, uranium, yttrium, and zinc. Of these, aluminum, arsenic, barium, bismuth, cadmium, calcium, carbon, cobalt, columbium, fluorine, hydrogen, iridium, iron, lithium, magnesium, manganese, nickel, nitrogen, phosphorus, scandium, sodium, sulphur, tungsten, uranium, yttrium, and zinc have plus variations, while boron, bromine, caesium, didymium, gallium, lead, osmium, palladium, selenium, silver, thorium, tin, and titanium fall slightly under the units to which they approximate. Oxygen, as the standard of comparison, of course shows here no variation, its possible error having been transferred to hydrogen. Of the foregoing elements it will be seen that twenty-six have plus variations from whole numbers, while thirteen are minus. Among the latter, boron, gallium, osmium, palladium, thorium, and titanium have been but roughly determined. Bromine, by Dumas' correction, has its variation diminished. In the cases of lead, cfesium, selenium, and tin, the cause of variation, supposing one to exist, remains to be determined. The value for osmium is undoubtedly several units too high, so that its agreement with Prout's law may be considered purely accidental. As for didymium, the figure assigned is the mean of all determinations; whereas Cleve's data, calculated with SO, = 80, make Di = 147.021, a variation which, like mnost of the others, is far within the limits of ordinary experimental error. In the 268 THE ATOMIC WEIGHTS. case of silver it has already been shown that Dumas' correction is unfavorable to it considered in its bearings upon Prout's law. Silver is the only element among those having minus variations which could carry very much weight against the hypothesis. Among the elements whose variations are plus, columbium, uranium, and yttrium have been poorly determined. Yttrium especially may be considered doubtful. The atomic weights of aluminum, arsenic, barium, cadmium, lithium, phosphorus, and sodium involve Dumas' correction to a greater or less extent, and will be lowered by its application, that is, brought nearer to whole numbers. For aluminum, certain other causes for variation were pointed out in the chapter upon that metal; and it may be noted that the direct ratio between it and hydrogen gives Al = 27.998, -.007. Here the variation is less than the probable error. For calcium, and consequently for fluorine also, sources of plus error were indicated in the discussion of their respective atomic weights, and reiteration here is unnecessary. Cobalt, iridium, iron, nickel, and tungsten all involve such errors as may arise from the possible occlusion of hydrogen by the metals after reduction from their compounds. For scandium, the atomic weight, calculated with SO,3 = 80, becomes 44.032, a variation much within the limits of experimental error. For carbon and bismuth the variations are insignificant. In short, in the majority of instances the errors may be diminished by corrections which are in all probability needed, and which can be easily pointed out. The more carefully we scrutinize the data the more probable Prout's hypothesis appears. Among the twenty-six elements whose atomic weights are removed by more than a tenth of a unit from whole numbers, chlorine, rubidium, and strontium have values nearly half multiples of that of hydrogen, and in each case Dumas' correction will make the approximation still closer. Erbium, gold, indium, lanthanum, rhodium, ruthenium, silicon, and zirconium may be dismissed from consideration as too imperfectly determined to carry much weight in the present APPENDIX. 269 discussion. For chromium, copper, molybdenum, and vanadium I have no criticisms to offer; but the remaining elements may be considered individually. The value assigned to antimony, 120.231, is the general mean of Cooke's and Schneider's work upon the bromide, iodide, and sulphide. If Ag = 108, Br = 80, and I = 127, Cooke's data for the bromide and iodide give the following values for Sb, all of which fall within a tenth of a unit of the whole number 120: Early bromide series___ _-= Sb - I I9.901 Late " _____.__-___ --- 120.009 Iodide series _____ 119.973 In the case of cerium, the value assigned in the table is the general mean of all reputable determinations. But it is subject to doubt on account of the facts observed by Wolf and by Wing, whose ceroso-ceric oxide was white, while that of all other observers was yellowish. Wolf's and Wing's data, calculated with O = 16, give Ce = 138.039. Cerium, then, is not an established exception to Prout's law. Glucinumn and ytterbium have their atomic weights calculated from analyses of the sulphates. But if Prout's law is true, SO, = 80. Calculated with this figure, we have Gl = 9.096 and Yb - 173.016. Both elements thus fall within reasonable limits of variation from the hypothetical values. Iodine is one of the most important seeming exceptions. If we assume Ag = 108, and calculate the atomic weight of iodine only from the direct ratio between iodine and silver, we have, with Dumas' correction applied, I = 126.966; that is, it comes within one-tenth of a unit of the whole number 127. The atomic weight of mercury depends upon analyses of the chloride, oxide, and sulphide. Of these three compounds the purity of the chloride is most easily assured. Calculated from its composition, with C1 - 35.5, Hg 199.971. With so high an atomic weight small errors are easily multiplied. 270 THE ATOMIC WEIGHTS. For the atomic weight of platinum Senbert's data give five values, ranging both above and below the round number 195. Calculated with integer values for the other elements, three of these figures fall very close to 195, as follows: From per cent. Pt in (NH4)2PtC16..__Pt = I94.906 " " KPtCI6......." =194.933 From chlorine estimation in K2PtCl16_ -- 194.955 Potassium is the most serious exception of all. But if O - 16 and Dumas' correction be applied, the general mean from all the available data becomes K - 39.083. That is, potassium falls within the limit of 0.1 variation. The atomic weight assigned to tantalum is the mean of four values. Two of these, recalculated with integers, come out as follows: From per cent. K2SO4 in K2TaF7 __ __Ta - I81.912 4" ( Ta205 from (NH4)2TaF7 _____ " I82.020 For tellurium I need only call attention to the discrepancies between the several sets of determinations made by Wills. A reference to the chapter on tellurium will show that his figures give results ranging from Te -126.07 to Te -- 129.34. The mean value is therefore too much subject to doubt to carry weight as an exception. As for thallium, the last case to be considered, I have already shown that Crookes' data, recalculated with integer values for N and 0, give Tl = 204.008. That is, instead of an exception, we have here an admirable instance in suppQrt of Prout's hypothesis. Enough has been said in this brief resume6 to show that none of the seeming exceptions to Prout's law are inexplicable. Some of them, indeed, carefully investigated, support it strongly. In short, admitting half multiples as legitimate, it is more probable that the few apparent exceptions are due to undetected constant errors, than that the great number of close agreements should be merely accidental. I began this recalculation of the atomic weights APPENDIX. 271 with a strong prejudice against Prout's hypothesis, but the facts as they came before me have forced me to give it a very respectful consideration. All chemists must at least admit that the strife over it is not yet ended, and that its opponents cannot thus far claim a perfect victory. INDEX. A. Barium chloride and lanthanum sulphate 230 Allen and Johnson_- __ __ 91I and silver___ _____ 57 Allen and Pepys_ 6 and silver chloride___ 60 Aluminum-__ ________. 156 chromate ____ 121, 122 bromide__-___ ________- 159 metatungstate -_______ I147 chloride-_____ ______ 156 nitrate 6i oxide 1___56 selenite 177 sulphate__ 156 silicofluoride 85 Ammonia alum -__________ 58 sulphate and barium chloAmmonia chrome alum -_...... 120 ride. 6I Ammonium chloride______ __ 40 and barium chromate_ 121 chloroplatinate __-______ 251 and barium fluoride __ So cobalticyanide _____ 172 and barium nitrate ___ 6I fluotantalate 249 and barium selenite __ 177 iridichloride _255 and cerium dioxide,222, 224 molybdate ______-___ _ 139 and didymium sulphate, 236 Anderson 76 and glucinum sulphate, 97 Andrews ________57, 250 and gold ___ _ 63 Antimony - _ __.....- i88, 269 and indium oxide.... 219 bromide I198, 200 and lanthanum sulchloride, 190, I91, 193, I194, I197 i phate 229 iodide I99 and magnesium suloxide ____-_.___ I88, I90 phate.. Ioo sulphide -______ 189, I96, 200 and nickel potassium Antimony compounds, oxidation sulphate -.____ 170 of-__ --- 189, 191, 192, I93, I94 and thallium sulphate, 93 Antimony and potassium tartrate_ 194 and thorium sulphate_ 214 Arago _ 6, 39 and yttrium oxide. 241 Arfvedson.__. _._.____ 87, I27, 15I uranate _____ I51 Arsenic _____ _85 and uranyl acetate _____ — 151 bromide-___ I86 Beringer _ -_-_.____ _.__ 221 chloride _.___ _ I86 Berlin __ __ ___.__ i.__ 18, 139 trioxide - ____ I123, 187 Bernoulli. __. _-45 Arsenious oxide and potassium an- Beryllium. See Glucinum __. —- 96 hydrochromate _. -_-_123, 187 Berzelius__ I, 6, IO, I4, 19, 21, 27, 31, Arsenious oxide and potassium. 39, 6o, 6I, 68, 70, 72, 78, 82, 84, chlorate _ __ __ I87 86,87, Ioo, 0o8, 117, I27, 13, I35, Atomic weights, table of -_-. 265, 266 I37, I43, I5I, 156, I62, 176, I80, Awdeje __._ 97 183, I85, 188, 265, 212, 214, 248, 249, 254, 256, 258 B. Biot and Arago _ 6, 39 Bismuth...............___ 202 Bahr -____. _____ __ Io102, 242, 244 chloride ____ _..__ 203 Bahr and Bunsen __.-__-__ 242, 244 oxide._ 203 Balard -_.. _____-__ _-___- _ 21 sulphide-___ 202 Barium 57 Blomstrand ___ ___ __. _ 247 chloride and barium chro- Boisbaudran _ 218 mate. _____ 122 Borax_____ __ 84 and barium sulphate__ 70 Borch..___ _ ________.___ 144 and cerium sulphate__ 223 Boron _- ____ __-_____ -___ 84 13 273 274 INDEX. Boron bromide __ -__.____ ____ 84 Cobalticyanide of phenylalmmochloride__ _ _ __ 84 nium 172 Brauner-_____ __ ___ __ __ 96 of strychnia_ -___ ___ 74 Bromine__._...__ __.. __.. 9, 21 Columbic acid-_______.__ ___ 247 Brucia cobalticyanide_ _____-.__ 173 Columbium -__-___ _247 nickelocyanide 173 oxychloride ___ _ 247 Buehrig_____-___-__ ______ 226 pentachloride ____ __ 247 Buff __ 6 Cooke_ ___- __ 29, II2, 195, 1I98, 199 Bunsen_ __90, 91, 92, 220, 242, 244 Copper..1......... I35 Bunsen and Jegel -223 oxide_______.... I, 8, 56, I35 Burney _ _____ ___ 245 sulphate -_____________ I136 subsulphide __ __ 36 C. Crookes __________________ 95 Czudnowicz __ __- -__ 183, 233 Cadmium III bromide _ 112 chloride..... —...____ 112 D. oxalate_ —- ----- 112 sulphate _ I_______ II2 sulphate_________ ___ III Davy ____ _ 6, 78, 127 sulphide.____________ III Debray __8, I40 Qaesium _,_,__,, __,,,,,,,,_,,, Debray - - - 98, 140 Dium ecipium 246 bitartrate ____ _____ gI Delafontaine __ ___. 215, 242, 244 chloride-De Luca..... - 79 Calcium _.... 67 Demoly 7 _ _ _ 9 67 209 carbonate ____ DeSaussure 6 and calcium sulphate 69 Devile______ 84,248 chloride ____.-________ 70 Deville and Troost-.__________ 248 fluoride __________ _ 78 Dearand cott____.. _ 30 oxide and calcium sulphate, 70 Dexter and Scot- -3 0 sulphate _ _____ 69, 70 Diamond —----------- 54 Capitaine _____- - ______ ___ 3I Didymium __ _ __ 236 Carbon 50 chloride.. —--- 237 dioxide___ _____ 54, 56 oxalate.. --- 237 monoxide oxalate ___ _______ 237 Cavendish ____- -_ 6 sulphateo 236 sulphate,... - -236 Cerium -__-___ -____ _____ 221, 269 Diehl -- - 87 chloride —_ —_-__._- ____ 221 Dcebereiner____ ____ 72, 31 formate - _ -__ ___ __222 Dulong and Berzelius ____ I, 6, 39 oxalate- ___.__223, 224, 227 oxidalate __ 22 223,24, 227 Dumas, I, 2, i6, 27, 28, 30, 58, 64, 67 xsulpate, 221_ 222,. 224, 225 70, 75, 79, 80, 83, 84, 85, Io6, 112, sulphate, 221, 222, 223, 224, 225 128, I34, I36, I39, I45, I56, 167, sulphide-____-hlori__e 222 178, I8I, I86, 191, 203, 205, 206, Chlorine __ 9 26I Choubine alum _________ __ 229 Dumas and Boussingault.____ 6, 39 Chrom lum _20 and Stas __ __ __ 54 - 11Chromium _____ __________ II7 Dumas' correction __..-_...__ 26I acetate _._____ _ __ ____ I II8 chloride_ 24 sulphate 1 I20 Chydenius_ 214 Clark 2__ Claus _259 Ebelmen 1__52 Cleve __ 217, 234, 238, 240, 242, 246 Ekman and Petterson ___- _ 1____ I78 Cleve and Hoeglund _______ —- 242 Erbium 244 Cobalt _ _64 oxide ____.. 244 chloride-.......... I66, I67 sulphate -__________- ___ 244 oxalate-________ I66, 168 Erdmann (Axel) __ _____ Io8 sulphate __-___ ___.-_ I66 Erdmann and Marchand__ I,4, 28, 54, Cobalticyanide of ammonium - - 172 68, 69, II5, 132, 135, I64, 177 of brucia____- ____ I73. Erk -2_ 234, 238 INDEX. 275 F. 1 Indium sulphide _____ _ 219 Iodine__ _ ____ 9, 269 Faget __ ___........... ___ _ 12 and silver 25 Favre __-_-__ __-_________ I109 Iridium 254 Ferric chloride 134 Iron _______ _ _~ ___ 131 oxide 131 chlorides. _ 34 Ferrous chloride ____ 134 oxide I__ _____ __. 131 tungstate _- _ 147 tungstate 147 Fluorine. _____ __ __-_____ _ _ 78 Isnard _ 156 Fluor spar 78 Fourcroy _.. __ __ 6 J. Fremy 254 Jacquelain -_ —-__- 82, IoI, xo8, II8 G. Jegel _223 Johnson and Allen___ __ 9 Gallium __ -_________ 218 ammonium alum._ _ _._ 219 K. nitrate ----— _____ 219 oxide.___ 29 Kemp 4o_ _ Gay-Lussac ____ ____...-...__ Io8 Kessler 1____ 122, I87, 189, 191, I99 Genth --- __ —__ 226 Kirwan - 6 Gerhardt_._ -____________ I I Kjerulf 223 Glucinum __- _ 96, 269 Klatzo _98 and ammonium oxalate ___ 98 Kralovanzky -___. ____ 87 sulphate______ - - -_ ___ 97 Gmelin. __-____ -_____ ____ 87 L. Godeffroy __-_ ______- _- go90, 9I Gold_ -___1_ _________-____ I162 Lagerhjelm _._._.__ —- — ____ 202 and cobalt _.-_1__ ____ 172 Lamy_- ___.____ ____.____ 93 indium ----------- 220 Lanthanum -_- _____________-229 mercury- __ ___ 162 carbonate _____ ____ 233 nickel-______ _1_ 172 iodate-___.._ 232 phosphorus.-1 —— __ i63 magnesium nitrate...... 232 Graphite 54 oxalate _ _ ____ -___-___ 231 oxide __232 H. sulphate -__ __._ 229 Laurent ___ _____ 9, 84 Hagen --._._._.......__. ___ 87 Lavoisier 6, 39 Hampe __ I136 Lead_ __ __ 72 Hauer.-._. _._._._.. I I, 128, I8o chloride -74 Hebberling _-____ ____ ____ 93 chromate I 18 Hermann, 87, 212, 216, 222, 233, 238, fluoride 80o 247, 248 nitrate.... _ ----- 75 Hilgard. -__ _ _ I58 and lead oxide ___-__ 76 Hoeglund.__242, 244 and lead sulphate 74. Holmium____-__________ _.. 246 oxide __ —---------- 72 Holzmann ________-_-. __- _ 23I and lead sulphate _. 74 Humpidge___ ____ 96, 245 sulphate_.._-____ _____ 72 Humpidge and Burney _ ____ 245 and lead fluoride - _ —. 8o Huntington __ _ __ II2 and lead nitrate -____ 74 Hydrogen ____-___.. I, 3, 6, 7 and lead oxide _- __ _ 74 and aluminum -..... I57, I6o Le Conte ____ _ _- 7,40 cobalt_ _ —_-__-_- -- 169 Lee- ---- -- 172 nickel __ 169 Lefort_ 121 Lenssen~...................1 I 12 I. Liebig ______Liebig 2I, 51 Liebig and Redtenbacher — _-_- 5 Iceland spar 67 Liechti and Kenip -_ _-___ 140 *ndium -219 Lithium 87 oxide ___. _ 219 carbonate-__-_- ___ 87 276 INDEX. Lithium chloride 87, 89 Nickel oxalate _____...... _ 65, 166 nitrate — __ —-- _-____ — 89 oxide _____ 164, 168 sulphate 88 potassium sulphate -___-_ I170 Loewig 21 sulphate____- 1__.___ I65, I66 Longchamp_ 72 Nilson-____ ____ 96, 99, 240, 244 Louyet-___:__ _ -78, 79 and Pettersson.._ __ 96,99 Niobium. See Columbium______ 247 M. Nitrogen__ ____ 39 Nitzsch 176 Macdonnell____ __ __-TOO Ioo Nordenfeldt 0____ _2___ _____ Io2 Magnesite 103 Norlin 131 Magnesium _____oo carbonate_____ _____ I03 0. chloride Io6 lanthanum nitrate.. __ 232 Osmium__ ____ __254 oxalate_ __ I02 Oxygen__ oxide o1I sulphate______ oo00 P. uranate _. __ 151 Malaguti- _- _ —---- 143 Palladium _-___ _________ 256 Mallet 87, 157, 267 sulphide _____ _______ 256 Manganese 127 Peligot__ ___ II8, 151, 153 chloride __ __28 Pelouze, II, 32, 40, 57, 64, 82, 85, i86 dioxide____ __.____ 31 Penny -___ 0_._ Io, 15, 32, 41, 45, 47 oxalate __ 1_30 Pepys-___.. 6 sulphate 128 Persoz __ _______ _ 46 sulphide____ _ 128 Pettersson ________96, 99, 178 Manganoso-manganic oxide 129 Pfeifer 202 Marchand, I, 4, 28, 54, 68, 69, 103, Phenylammonium cobalticyanide_ 172 115, 1I32, 1I35, 144, 15I, I64, 177 Philippium _246 Marchand and Scheerer ________ I03 Phosphorus ___________. __ 82 Marignac, 9, II, I2, 14, 15, 16, 18, 19, and gold___ 163 22, 23, 25, 40, 42, 44, 57, 59, 6o, pentoxide -___________ 82 62, 65, 74, 166, 212, 222, 230, 231, trichloride _____ ___ 83 236, 237, 247, 248 Piccard _________ go Mather _ ___ _.___ _____ 156 Pierre____ _____ _ __ _ 208 Maumen. _ 9, I2, 19, 52, 133 Platinum -___ -____ 249, 270 Mendelejeff's law __ 96, 150, I80, 246 dichloride _______._ 249 Mercury.____- __- ___- _ I114, 269 Popp _____-_______________ 241 and gold I62 Potassium 9, 270 chloride-_ _ 1i6, 269 anhydrochromate ___ 123, 187 oxide ____.__.__. _ 115 and tartar emetic..._ 194 selenide _______-__ ___ 177 aurichloride__, ____ —--— _ 162 sulphide_____ _ x16 bromate 21__ _ 2I Meyer, Lothar-_ __ 96, 140 bromide____________ 23 Millon 24, ii6, 135 chlorate ___ _____ ___ io and Commaille. 1.___ I35 and arsenious oxide__ 187 Mitscherlich and Nitzsch — ___-. 176 and potassium nitrate_ 47 Moberg ____ __ ___ __ I20 chloride and gold __ __ 1. I62 Molybdenum __ __. _ 37 iridium ___. —-_ 256 c.llorides 140 osmium ___. —__ 254 sulphide-______ 137 palladium __-__ 257 trioxide 137 platinum _-_-__ 250 Mosander — ___.._____ 208, 229, 236 potassium nitrate_ 46 Mulder and Vlaanderen __ 205 rhodium ____.. _ 259 ruthenium 259 N. silver 18 silver chloride_ _I9 Nickel ~1_____.._______ __. _ _I64 silver nitrate ___ 44 chloride -- 1i66, 167 fluoride 70 INDEX. 277 Potassium fluoxycolumbate 247 Scheibler__ __ - 147 iodate..____ ___...___. 24 Schiel _._..__ ____ 86 iridichloride 254, 255 Schlippe's salt __ I195 nitrate and potassium chlo- Schneider, 129, 144, I65, I66, 171, I89, rate _ —__ 47 I99, 200, 203 nitrate and potassium chlo- Schr6tter 82 ride _ —---------- 46 Sefstr6m - ----- -114 osmichloride __ __ — 254 Seguin 6 palladichloride 257 Selenium ___- - I176 palladiochloride --------- 257 chloride _- I176, 178 perchlorate ------------ I I dioxide —------- 176, I79 platinochloride 250, 252 Seubert _______251, 255 rhodiochloride_ _-__ —-- 258 Siewert __ 124 rutheniochloride __ —--- 259 Silicon..- - 85 sulphate and potassium fluo- chloride-_ _ -- 85 ride __ —_____ 70 dioxide __-____________ 85 and potassium tantalo- Silver 9 fluoride _ _ 248 and aluminum bromide _-_ i6o and thoria --------- 214 chloride _.__ I57 and zirconia __.-_ — 213 ammonium chloride __ 40 tantalofluoride -____.__ 248 antimony -_ —----- 202 tartrantimonite -______ — I94 bromide _ 200 zircofluoride -- 2I3 chloride _._-_ I9I Prout's hypothesis _____ ____ _ 261 arsenious bromide _ I87 Purpureo-cobalt chloride I.. 171, 174 chloride _ -_ ____ I86 barium chloride _____ 57 Q. | bismuth chloride... 204 cadmium bromide ___ 113 Quintus Icilius 257 chloride2:__ calcium chloride _._ 70 cobalt chloride _ —— _ I68 R. ferric chloride — ___. I34 ferrous chloride -_-_-_ I34 Rammelsberg, 142, I5I, 224, 229, 247 lead chloride..__- 3 74 Rawedtachker, —---. _ _ -- --- -_____ I29 lithium chloride: _ 89 XRedtenbacher _ ______ ____ - -,,- -- 5 I magnesium -chloride__ io6 Regnault - -... 6, 39, I50 manganese chloride__ 128 Reich and Richter 219 nickel chloride9____ I68 Reynoldsim —.___ _____ —- _ 96 phosphorus trichloride, 83 Rhodium.258 Richedim. —- ----— 146- ^- --- 258 potassium bromide___ 23 Riche~ _ —-- 1_ _ _ ____________I46 chloride_____.__ I18 Richter - - 219 iodide ___- 25 Rivot.______________________I'33 silicon chloride ___- _ 85 Roscoe —-- -- -- -------- 146, I83 silver nitrate — __... 41 Rose 1I90, 207, 247, 248 sodium chloride _ _ 32 Rothhoff -64 strontium chloride ___ 64 Rubidium,,,,, -__go tin tetrachloride-_ _ 206 chloride __ __-_-9___go titanium chloride _- 208 Russell- i,-, - 168, 169 vanadium oxychloride, 184 Ruthenium —----- ----------— __259 occlusion of oxygen by__. 262 acetate 51, 53 S. anhydrochromate __ II119, 125 bromate 21 Sacc______ ______.______._____ 176 bromide __-__ 22 Salvetat- — _, _____ ____ 57, 64, 67 and antimony bromide I98 Samarium - --- -246 and boron bromide-__ 84 Scandium - - 240 and cadmium bromide, I 12 oxide 240 and silver chloride___ 21 sulphate _____ ____. 240 and tellurium potassiScheerer -_______ IOO, 101, 103, I05 um bromide, i8o, I8i 278 INDEX. Silver chlorate __4 I Sodium susulphantimonite -_-_ — 195 chloride 14 uranate - _____ _-_____ 153 and ammonium platin- Sommaruga___ ___ I70 chloride ___-__ —_ 252 1 Soret's earth X 246 and antimony chloride, Stas, I3, 14, I6, 18, 21, 22, 23, 24, 25, I94, 197 26, 28, 30, 32, 38, 40, 41, 42, 43, and barium chloride__ 60 44, 46, 48, 54, 55, 73, 75, 89 and boron chloride___ 84 Stibnite _____ __ _ __ 89, 200 and ceroso-cericoxide, 22I Stromeyer ______-.. 64, 87, III, I3I and chromic chloride_ 124 Strontium ___ 64 and didymium oxide_ 237 chloride and silver -—... 64 and lithium chloride - 87 and strontium sulphate, 66 and manganese chlo- Struve-_____ _ 30, 31, 6I, 137 ride......... I28 Strychnia cobalticyanide - I_ 174 and molybdenum chlo- nickelocyanide 173 rides -_ -_ -_ 14I Sulphur _____ ___9, 27 and potassium chlo- Svanberg, —3I, 76, 102, II6, 131, 137, ride _ —1 9 and Nordenfeldt _._.__-__ 102 and potassium platin- and Norlin _-___.. I31 chloride _-___ 253 and Struve ____-_ — —. 31, 137 and rubidium chloride, go and silicon chloride__ 86 T. and silver bromide -_ 21 chromate ___ II9 Tantalum —____._____. 248, 270 iodide _..__ 27 oxide -_._. ______.___ 248 nitrate -__.. 43 Tartar emetic_ I94 sulphide __ 31 Tellurium _ —------------ I80, 270 tungstate 1__ I49 dioxide..___...___ I 80, i8 and thallium chloride, potassium bromide _-_ I 8o, 181 93, 94 Terbium _246 and titanium chloride, 207 Terreil ______ 157 dioxide_ 207, 2Io Thalen -. __ 246 and vanadium oxychlo- Thallium.... —--------— _ —.. 93 ride......... I85 chloride _.________._____ 93 chromate___ —_ I I9 iodide_ 94 iodate-..... 24 nitrate_ —-___ _-___-95 iodide_. —------------- 25 sulphate --------------- 93 and antimony iodide _ I99 Thomsen ___ 8 and silver chloride___ 27 Thomson -_ —---— __ __ —___ _ 6, 39 and thallium iodide-_ 94 Thorium_ 214 malate 52 acetate__ _ ___ __ 215 nitrate 41 formate 215 andpotassium chloride, 44 oxalate-__ ____ ___ 215, 217 and silver chloride__- 43 oxide - - 214 oxalate-__.. __ 53 sulphate__ ____ 214, 215, 2I7 permanganate _-_..__ 1_ 3 I Thulium _______ __ 246 racemate _ 5 Tin_. 204 selenite 1 _ __ 78 dioxide _~. 205 sulphate-_____ __ _____ 30 tetrachloride _ 206 sulphide-_____ ____ ___ 28 Tissier 156 and silver chloride __ 31 Titanium __ __ ___ 207 tartrate -_ _ ___ ___ 5I ammoniochloride ___ —-_ 2Io0 tungstate --— ____-___ 149 chloride __-_-__- 207, 209, 210 Sodio-uranic acetate- _____. 151, 153 dioxide- ____ 207, 208 Sodium ----------------- 9, 31 sulphide ______________ 207 chlorate 32 Troost. -________ ___ 88, 248 chloride _____- _____ 32 Tungsten-'_____ _____ ______ 143 columbate - ___ 247 oxides ___ _ I43 fluoride _70 Turner__I5, 6o, 6i, 73, 114, II5, I 6, rhodiochloride - _- ___ 258 I27 INDEX. 279 U. Winkler ___._ __-.. 171, 219 Wolf.__ __ 224 Unger I95 Wrede _-__.____ _ 6 Uranium _-_______ —--- 150 acetate 153 X. oxalate-_____._ 1 52 oxides 151 X, Soret's earth-_ __ 246 sulphate 1_________ 5 I51 tetrabromide _ _ 150 Y. tetrachloride _-___- I150, I51 Ytterbium _243, 269 V, oxide ------— __ -__- __- - 243 sulphate-.._.__...__.. 243 Vanadium 1_83 Yttrium ___- _________________ 241 oxides -_____________-__ 183 oxide _-_______-_ 241 oxychloride-_____-_____ 184 sulphate _-_- _ 241 Vauquelin __ __ ___ 6 Vlaanderen-______ __- _ 205 Z. W. Zettnow__ ______ I47 Zimmermann _ _ __ ____ _ _ _ 50 Wackenroder _ __ I3 Zinc _ __ Io8 Wallace __ _._ __ 21, I86 oxalate ____ ____ IO9 Weber _ ____..... i90 oxide _.______ IoS Weeren _ _ _.___ 97 Zirconium -- ___.__. 212 Wertheim _. 153 chloride __- _- _ 212 Weselsky... - -. _ _ _ I72 dioxide 212 Wildenstein- _ _ _ _1 ___ — __ I122 potassium fluoride _-_ _-_ 212 Wills___ I8 sulphate 212 Wing _ — _ — -- __-_ 226 Zschiesche_ ___ 233, 238