MEDICAL tSCH<S>>L 
 
 FROM THE LIBRARY OF 
 FRANK BRANSON PETRIE, M.D. 
 

LABORATORY TEACHING: 
 
 OE, 
 
 PROGRESSIVE EXERCISES IN PRACTICAL 
 CHEMISTRY. 
 
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LABORATORY TEACHING 
 
 PROGRESSIVE EXERCISES 
 
 PEACTICAL CHEMISTRY. 
 
 BY 
 
 CHARLES LOUDOKtELDXAM, 
 
 PROFESSOR OF CHEMISTRY IN KING'S COLLEGE, LONDON J 
 
 IN THE DEPARTMENT OF ARTILLERY STUDIES, WOOLWICH, AND IN THE 
 
 ROYAL MILITARY ACADEMY., WOOLWICH. 
 
 FOURTH EDITION, 
 
 WITH 
 
 EIGHTY-NINE ILLUSTRATIONS. 
 
 187? 
 
 PHILADELPHIA: 
 LINDSAY AND BLAKISTON 
 
COr. LINS, PRINTER. 
 
PREFACE 
 
 TO 
 
 THE FOURTH EDITION 
 
 THE most important alteration in the present Edition is 
 the introduction of the formulae representing the various 
 chemical compounds described in the Notes to the Tables. 
 The formulae are those now generally employed by chemical 
 writers and teachers in this country. 
 
 The verbal description of the composition in the Tables 
 of Common Compounds of the several metals has not been 
 altered so as to bring it into perfect harmony with the 
 formulae, since the description there given generally informs 
 the learner what substances can be obtained by the decom- 
 position of the Common Compounds, which is not so easily 
 to be ascertained by an inspection of the formulae. 
 
 For example, the composition of saltpetre is described at 
 page 81, as Potash (Potassium and Oxygen) and Nitric 
 Acid, whilst the formula KNO 3 does not indicate the pre- 
 sence of potash (K 2 O) or of nitric acid (HNO 3 ) ; but both 
 these substances are obtainable from saltpetre by very 
 
Vi PREFACE TO THE FOURTH EDITION. 
 
 simple chemical operations, and saltpetre may be produced 
 by causing them to act upon each other. 
 
 It is true that similar reasoning would justify the state- 
 ment that common salt contained soda and hydrochloric acid 
 instead of sodium and chlorine, but the Author feels that 
 an endeavor to be absolutely consistent would injure the 
 practical usefulness of so small a book. 
 
 May, 1879. 
 
PREFACE 
 
 TO 
 
 THE FIRST EDITION 
 
 THIS work is intended for use in the Chemical Laboratory 
 by those who are commencing the study of Practical 
 Chemistry. It contains 
 
 (1) A series of simple Tables for the analysis of unknown 
 substances of all kinds (not excepting organic bodies) 
 which are known to be single substances, and not 
 mixtures : 
 
 (2) A brief description of all the practically important 
 single substances likely to be met with in ordinary 
 analysis, by which the learner may satisfy himself 
 that his results are correct, and may at the same time- 
 become acquainted with the leading properties of the 
 most important chemicals, and with the foreign sub- 
 stances which they are liable to contain : 
 
 (3) Simple directions and illustrations relating to Che- 
 mical Manipulation, not collected into a separate 
 chapter, but given just where the learner requires 
 them in the course of analysis : 
 
Vlll PREFACE TO THE FIRST EDITION. 
 
 (4) A system of Tables for the detection of unknown 
 substances with the aid of the Blowpipe : 
 
 (5) Short instructions upon the purchase and preparation 
 of the tests, intended for those who have not access to 
 a Laboratory. 
 
 The book does not presuppose any knowledge of Che- 
 mistry on the part of the pupil, and does not enter into any 
 theoretical speculations. 
 
 It dispenses with the use of all costly Apparatus and 
 Chemicals, and is divided into separate Exercises or Lessons, 
 with Examples for Practice, to facilitate the instruction of 
 large Classes. 
 
 The Author hopes that it will be found to contain all the 
 Practical Chemistry required for the various Examinations, 
 except for the highest Science degrees, such as the B.Sc. 
 and D.Sc. of the University of London. 
 
 The method of instruction here followed has been adopted 
 by the Author after twenty-three years' experience as a 
 teacher in the Laboratory, by which he has been led to 
 conclude that a knowledge of Analytical Chemistry, or the 
 power of discovering the nature of unknown substances, is 
 the first and often the only requirement of the great majority 
 of learners, and that, independently of the technical value of 
 such knowledge, its acquisition forms a most valuable part of 
 education, by cultivating the powers of observation, and 
 affording excellent examples of the application of logical 
 reasoning in practical work. 
 
 The ordinary method of teaching Analytical Chemistry, by 
 causing the pupil to study the Reactions or tests for all the 
 metals and non-metallic bodies, before he proceeds to exa- 
 
PREFACE TO THE FIRST EDITION. IX 
 
 mine an unknown substance, does, without doubt, lay the 
 best foundation for a thorough knowledge of this branch of 
 Science, when a student has time at his command, and can 
 commit to memory a large number of independent facts 
 which receive no immediate application. But, within the 
 Author's experience, many students become wearied with 
 the monotonous routine of this system, and are prevented 
 from persevering in the study. 
 
 Moreover, such a system, although teaching the student 
 to discover, for example, that a given salt contains potassium 
 and nitric acid, fails often to instruct him that these consti- 
 tute saltpetre, and does not acquaint him with the appear- 
 ance and other properties of saltpetre, by observing which 
 he may be sure that his analysis is correct. For want of 
 such an acquaintance with the properties of the common 
 salts, a student well skilled in the mere detection of bases 
 and acids will sometimes fall into .the most absurd mistakes 
 as to the nature of a substance under examination. 
 
 Those students who can afford the time are strongly 
 recommended to perform every experiment described in the 
 book, with the known substances, before attempting the 
 examination of an unknown substance. 
 
 April, 1869. 
 
 *^* A List of the Apparatus and Chemicals required for 
 the Course will be found at pp. 228-243. 
 
CONTENTS. 
 
 PARAGRAPHS 1 31. Analysis of substances containing a single 
 metal. Solution. Filtration. Precipitation. Division of the 
 metals into groups. Identification of the individual members 
 of each group. Description of the metals and of their chief 
 oxides and salts. 
 
 PARAGRAPHS 82 121. Analysis of substances containing a single 
 inorganic acid or non-metallic body. Expulsion of acids from 
 their compounds by sulphuric and hydrochloric acids. Pre- 
 cipitation of acids by barium nitrate, silver nitrate, calcium 
 chloride and ferric chloride. Description of the principal in- 
 organic acids. 
 
 PARAGRAPHS 122 141. Analysis of substances insoluble in water 
 and acids. Fusion. Description "of the principal insoluble 
 substances. 
 
 PARAGRAPHS 142 162. Analysis of substances which may contain 
 one metal and one organic acid. Description of the principal 
 organic acids, and their common salt. 
 
 PARAGRAPHS 163 171. Detection of the principal vegetable alka- 
 loids. Identification of caffeine, morphine, brucine, strychnine, 
 quinine, narcotine, and cinchonine. 
 
 PARAGRAPHS 172 176a. Identification of the more common organic 
 substances characterized by color or odor. Indigo. Picric acid. 
 Caramel. Carbolic acid. Chloral hydrate. 
 
 PARAGRAPHS 177 205. Examination of a solid organic substance 
 having no definite color or odor. Identification of cane-sugar, 
 grape-sugar, milk-sugar, urea, pyrogalline, salicine, albumen, 
 starch, dextrine, gum, gelatine, soap, stearine, stearic acid, 
 palmitic acid, cholesterine, rosin, naphthaline, palmitine, sper- 
 maceti, wax, and paraffine. 
 
Xll CONTENTS. 
 
 PARAGKAPHS 206 229. Examination of a liquid organic substance 
 having a very distinct odor. Identification of alcohol, methy- 
 lated spirit, wood-naphtha, acetone, aldehyde, nicotine, butyric 
 acid, valerianic acid, aniline, ether, chloroform, oil of bitter 
 almonds, nitrobenzole, and benzole. Distillation. 
 
 PARAGRAPHS 230 234. Examination of a liquid organic substance 
 having no distinct odor. Identification of glycerine, lactic acid, 
 oleine, and oleic acid. 
 
 PARAGRAPH 235. Examination of a solid organic substance about 
 which nothing is known but that it is a single substance and 
 not a mixture. 
 
 PARAGRAPH 236. Examination of a liquid organic substance about 
 which nothing is known but that it is a single substance and 
 not a mixture. 
 
 PARAGRAPH 237. Examination of a solid substance of which 
 - nothing is known but that it is a single substance and not a 
 mixture. 
 
 PARAGRAPH 238. Examination of a liquid of which nothing is 
 known but that it is a solution of a single substance and not a 
 mixture. 
 
 PARAGRAPH 239. Examination of an organic substance which is 
 known to be included in the list given for the 1st M.B. Exami- 
 nation of the University of London. 
 
 PARAGRAPHS 240 282. Detection of metals by the blowpipe. 
 Reduction on charcoal. Borax-Beads. Colored flame test. 
 Cobalt test. Sublimation test. Cupellation. 
 
 PARAGRAPHS 283 307. Detection of non-metals or acids by the 
 blowpipe. Heating with bisulphate of potash. 
 
 PARAGRAPHS 308 363. Alphabetical list of test used in analysis. 
 PARAGRAPH 364. Apparatus required in qualitative analysis. 
 APPENDIX. Qualitative Analysis of Gunpowder. 
 
LABORATORY TEACHING; 
 
 OR, 
 
 PROGRESSIVE EXERCISES IN PRACTICAL 
 CHEMISTRY. 
 
 INTRODUCTION. 
 
 THE instructions given in this work are intended to enable 
 the student to discover the nature of most of the chemical 
 compounds in common use. 
 
 When nothing is known about the* substance, its examina- 
 tion must be commenced according to Exercise XIII. (para- 
 graph 237) if it be a solid, or XIV. (paragraph 238) if it be 
 a liquid. 
 
 But it is better for beginners to confine their attention to 
 ordinary inorganic salts, which may be commenced by Table 
 A. For the first few lessons, the detection of the metal, by 
 Tables A to F, will suffice. 
 
 Having detected the metal, the student should turn to the 
 description of that metal and its common compounds, and 
 endeavor to name the unknown body under examination. 
 
 When he is well versed in the detection of the metal, he 
 may proceed to discover the non-metallic body or acid which 
 composes the other portion of the compound. 
 
 In many cases, where a substance has a peculiar color or 
 smell, a reference to that color or smell in the Index may 
 lead to its identification. 
 2 
 
14 INTRODUCTION. 
 
 The learner will find it advantageous to study the list of 
 the principal tests, commencing with paragraph 308, since 
 he will there find the formulae expressing their composition, 
 and a list of the substances, the presence of which is indicated 
 with certainty by the action of any particular test. 
 
 The numerals inclosed in parentheses in each Table refer 
 to paragraphs in the text, and it will be found absolutely 
 necessary to refer to these in order to render the Tables 
 serviceable. 
 
 A rough note-book should be provided, in which every 
 step of the analysis should be entered, the symbols being 
 employed for the tests, both to avoid much writing and to 
 fix their composition in the memory. 
 
 A Report of an Analysis is appended as a model. 
 
REPORT OF ANALYSIS. 
 
 15 
 
 o" 
 
 I? 
 
 CTS u 
 
 ^l/ 
 
 o d 8 -g gl 
 ^g5^ s ^o 
 ^5 ^^ 
 
 ft * bC 15 'c 
 
 .2^0 "S g 
 
 
 .O 
 
 o'to"! 
 
 o 
 -3 
 o 
 
 rt ^ 01,^ - 
 
 Cx^ HH 32 
 
 os ~ ^ .23 
 P5 ^ 
 
 o-jP 
 
 a 
 
1C 
 
 TABLE OF ATOMIC WEIGHTS. 
 
 The subjoined Table indicates the relative weights of the 
 Elementary Bodies represented by the symbols composing 
 the formulae given in this work. 
 
 Aluminium 
 
 . . Al 
 
 27-5 
 
 Lead . . 
 
 . . Pb 
 
 207 
 
 Antimony . 
 
 . . Sb 
 
 122 
 
 Magnesium 
 
 . . Mg 
 
 24-3 
 
 Arsenic . . 
 
 . . As 
 
 75 
 
 Manganese 
 
 . . Mn 
 
 55 
 
 Barium . 
 
 . . Ba 
 
 137 
 
 Mercury 
 
 . . Hg 
 
 200 
 
 Bismuth 
 
 . . Bi 
 
 210 
 
 Nickel . . 
 
 . . Ni 
 
 59 
 
 Boron . . 
 
 . . B 
 
 10-9 
 
 Nitrogen . 
 
 . . N 
 
 14 
 
 Bromine 
 
 . . Br 
 
 80 
 
 Oxygen 
 
 . . O 
 
 16 
 
 Calcium 
 
 . . Ca 
 
 40 
 
 Phosphorus 
 
 . . P 
 
 31 
 
 Carbon . . 
 
 . . C 
 
 12 
 
 Platinum . 
 
 . . Pt 
 
 197-1 
 
 Chlorine 
 
 . . Cl 
 
 35-5 
 
 Potassium 
 
 . . K 
 
 .39-1 
 
 Chromium . 
 
 . . Cr 
 
 52-5 
 
 Silicon . . 
 
 . . Si 
 
 28 
 
 Cobalt . . 
 
 . . Co 
 
 59 
 
 Silver . . 
 
 . . Ag 
 
 108 
 
 Copper . . 
 
 . . Cu 
 
 63-5 
 
 Sodium . . 
 
 . . Na 
 
 23 
 
 Fluorine 
 
 . . F 
 
 19 
 
 Strontium . 
 
 . . Sr 
 
 87-5 
 
 Gold . . 
 
 . . Au 
 
 196-6 
 
 Sulphur 
 
 . . S 
 
 32 
 
 Hydrogen . 
 
 . . H 
 
 1 
 
 Tin 
 
 Sn 
 
 118 
 
 Iodine . . 
 
 . . I 
 
 127 
 
 Tungsten . 
 
 . . W 
 
 184 
 
 Iron . 
 
 Fe 
 
 56 
 
 Zinc . 
 
 Zn 
 
 65 
 
TABLE A. 
 
 17 
 
 O 
 
 a 
 
 's 
 
 a 
 o 
 
 
 
 So 
 
 K m O 
 
 i 
 
 S 
 
 -ia "^ B <-T 
 
 => *** ~ I ^ 
 
 1 ss. 
 
 
 
 r( 
 
 H hD 
 
 1 fl 
 
 -**,- 
 
 
 - 
 
 J - ffl 
 
 " 
 
 W o 
 
 ? ^'S 
 
 s ^0*5! 
 
 
 0-5 
 
 ,3 
 
 2 t> 
 0) P 
 
 s 
 
 
 
 02 
 
 CH 
 O 
 
 I 
 
 'a . ^ > -J 
 ^C^ -8 5 
 
 ^g-r 38 -a, S 
 
 f-e^ S? Sfl^-feg? 
 
 l||s^| |||||^ 
 
 o* 
 
 -^ a 
 
 l 
 
 < '> 13 * 
 
 oT ss - "^ 
 
 3 .f e8*- 
 
 5 51 M 
 
 = l.s| 
 
 trong smell of the gas, 
 visable to evaporate do 
 e hydrosiilphate of am 
 ccouut of the transpar 
 
 I fllll 
 
18 
 
 INSTRUCTIONS ON TABLE A. 
 
 
 03 
 
 
 5 'S 'o . v 
 
 
 .1 
 
 
 "o & ^ S ^5 
 
 
 P 
 
 
 
 
 ^k 
 
 
 . 2 * I S~ il 1 
 
 
 OQ 
 
 
 > "5 2 -^ * 5 - -2 
 
 
 
 
 . * *" S "g s | 
 
 
 o 
 
 
 5 3 Ills 
 
 
 o 
 
 
 S'S^* ^<!'l 
 
 . 
 
 1 
 
 
 a ^ll 
 
 pa 
 
 ..c 
 
 
 II | J-!s ^- . 
 
 w 
 
 H 
 
 S| 
 
 1 
 
 || 5 o g .S | m g u 
 
 1-1 J3 a, Kffi < '*' s 9 S "^ . 2 
 
 ^ 
 
 .S "^ 
 
 s 
 
 - te 58^59 1 1 3 
 
 O 
 
 11 
 
 i 
 
 I'll i!^^^' 3 
 
 fc 
 
 Cv o 
 
 ^ 
 
 "6 u 1 1 3 
 
 1 
 
 II 
 
 bD'-S 
 
 p 
 
 <S 
 fl 
 
 ! | g ^ a 1 1 | -| 
 
 P 
 
 c 'S 
 
 .2 
 
 o*te d *.S-2* --^ s" ~" 
 
 n 
 
 '^ 
 
 a 
 
 ""S S^cS^'U^- 2 'S6|-"-Ss 
 
 HH 
 
 
 CO 
 
 S 
 
 If II !l!iil i'llllli 
 
 Q 
 
 J 
 
 1 
 
 ii "" a ifiii 
 
 
 g g~ 
 
 
 is .S 'a *o o .5 5 
 
 "*^ 
 
 
 
 
 ^ ^ 1 t, t, 0) 1 
 
 03 
 
 |-5 
 
 1 l c 
 
 3 
 
 
 
 rH 
 
 s^ 1 1.5 Is ^ *; ^ 
 
 || 2 21 1 1 ^1 
 
 O 
 
 hH 
 
 a;s 
 
 -u 
 
 >) 
 
 
 PLANAT 
 
 |1 
 
 ^ o 
 
 1 
 
 1 
 
 "^m S -S "^ , rS PH^ot;Ca o 'S 
 
 T S 2 C 2 S- * ^ -^wS^^Sg 
 
 5 .S .2 1 s -| * l^pSi'.sls; 
 
 || S -3|-^^| ^ ^ | R 6 ^ 3 ^ 
 
 h*! 
 
 
 
 -( .1-1 
 
 rN 
 
 -, 
 
 
 ^ w ^^ ^ 
 
 w 
 
 1 
 
 
 ii i ll|i ti 
 
 
 "^ 
 
 
 ''-2^ a*^"^ ^i 
 
 
 a 
 
 
 l32,.8~r;3 j^g 
 
 
 
 oS 
 
 
 1-1 si, riffi's^ c ''a ^"-^^^ 
 
 
 L, 
 
 
 g P, g^^-g-^ra PH:,? C 
 
 
 
 
 
 
 
 fV^ 
 
 
 ^5 P3 C'^'oiJ ^?>*^O 
 
 
 . 
 
 
 =- il 5 I^-^l* t^^^p 
 
 
 Ol 
 
 
 ^*^W O-'-'o'S m 
 
 
 
 
 H ^ s ^ s .s S s 
 
SOLUTION. BOILING. 
 
 19 
 
 3. To dissolve the substance for analysis,\>\<\.c,Q about five 
 grains of the powdered substance (as much as can be taken 
 easily on the end of the large blade of a pocket-knife) in a 
 
 Fia. 1. 
 
 Test-tube rack. 
 
 Test-tul>e. 
 
 Tube cleaner. 
 
 Fia. 2. 
 
 test-tube (fig. 1), pour upon it about two drachms (two tea- 
 spoonfuls) of distilled water, shake them together, and if 
 necessary, boil the water 
 over the flame of a spirit- 
 lamp (fig. 2) or a gas-burner ; 
 in the latter case, holding the 
 tube a little above the flame, 
 so as not to smoke it (figs. 3 
 and 4). The tube may be 
 held in a band of folded pa- 
 per when it is necessary to 
 boil for some time. 
 
 Fia. 3. 
 
 Fro. 4. 
 
20 
 
 SOLUTION. FILTRATION. 
 
 If the substance does not appear to diminish in quantity, 
 it may be set down as undissolved by the water. 
 
 Fl 5 - Should there be any 
 
 doubt, filter the solution 
 (4), catch a drop of it 
 upon a piece of thin 
 window glass, and eva- 
 porate it at a gentle heat 
 (fig. 5). If no consider- 
 able residue of solid 
 matter is left, the substance may be considered insoluble. 
 
 Should water have failed to dissolve the substance, pour 
 off the water so as to leave the powder, if possible, at the 
 bottom of the tube ; pour upon it about a drachm of diluted 
 hydrochloric acid, and boil if necessary. 
 
 If the substance be insoluble in hydrochloric acid, boil a 
 fresh portion, in another tube, with diluted nitric acid, and 
 should this fail to dissolve it, add a few drops of nitric acid to 
 the hydrochloric acid previously employed, and again boil. 
 
 Substances which are insoluble in water and acids must be 
 examined according to Table I. 
 
 4. To filter a solution. Take a circular piece of white 
 filtering (blotting) paper, three or four inches in diameter, 
 fold it neatly as in fig. G, open it so as to form a cone, place it 
 
 Fia. 
 
 FIG. 7. 
 
TESTING. EXCESS. 21 
 
 in a funnel, moisten it with distilled water, support the fun- 
 nel in a test tube, as in fig. 7, and pour upon it the solution 
 to be filtered. Should the funnel happen to fit air-tight into 
 the test-tube, interpose a little piece of wood or paper to 
 leave a passage for the air. 
 
 If the first filtration does not clear the liquid, it must be 
 poured, back through the same filter. 
 
 5. Addition of tests to liquids As a general rule, tests 
 are gently poured, drop by drop, down the side of the test- 
 tube (fig. 8), which is 
 
 gently shaken, until FlG< 8 - 
 
 either the expected 
 effect is produced, or 
 a reasonable propor- 
 tion of the test has 
 been added without 
 any result. The stop- 
 per of the bottle 
 
 should not be laid upon the table, but should be held be- 
 tween the second and third fingers of the left hand, as in fig. 
 8, and the label of the bottle should always be upwards. 
 
 Excess In cases where the test is to be added in excess, the 
 
 addition is continued until no further effect is produced by 
 adding another portion, and until some conspicuous property 
 of the test becomes evident in the liquid to which it is added. 
 
 Thus, Hydrosulphuric Acid is known to be in excess when 
 a strong smell of it is perceived at the mouth of the test-tube 
 after closing the tube with the thumb, and violently shaking 
 it. Since the strongest hydrosulphuric acid only contains 
 about three times its volume of sulphuretted hydrogen gas, it 
 is necessary to add this test in large quantity, often amount- 
 ing to three or four times the volume of the liquid to be 
 tested. Again, Ammonia would be known to have been 
 added in excess by its powerful odor, but if the liquid tested 
 be strongly acid, it is not advisable to close the tube with the 
 thumb when shaking it, as the action of ammonia upon 
 
22 
 
 STIRRING-RODS. 
 
 FIG. 9. 
 
 strongly acid liquids is of a violent character. The solution 
 
 may be mixed by pouring from one tube into another. 
 
 6. Precipitation promoted by stirring. The formation 
 
 of the precipitate of phosphate of ammonia and magnesia is 
 
 much facilitated by stir- 
 ring the liquid with a 
 glass rod, or, still better, 
 by rubbing the rod against 
 the side of the tube (fig. 
 9), the latter being held 
 in an inclined position, 
 and the rod held short so 
 that it cannot possibly be 
 
 thrust through the bottom of the tube. 
 
 To make a stirring-rod The glass rod used for this pur- 
 pose should be about six 
 inches long, and round- 
 ed at both ends. To 
 make it from one of the 
 long glass canes sold at 
 the glass-house, cut off 
 six inches by making 
 a deep' scratch with a 
 three-cornered file, and 
 breaking the rod at this point 
 by a sharp jerk (fig. 10). 
 Fuse each end in the extreme 
 point of the blowpipe flame 
 (fig. 11) till well rounded. 
 The glass must not be intro- 
 duced into the inner part of 
 the flame, or it will be per- 
 manently blackened, from 
 the separation of lead in the 
 metallic state. 
 
 FIG. 11. 
 
MAGNESIUM AND ITS COMPOUNDS. 26 
 
 NOTES TO TABLE A. 
 
 r l. The deposition of sulphur from the hydrosulphuric 
 acid may be due to a variety of causes ; for example, to the 
 presence of nitrous acid derived from the nitric acid em- 
 ployed in dissolving the substance ; to free chlorine ; ferric 
 chloride (perchloride of iron) ; sulphurous acid ; chromic 
 acid. 
 
 8. Chloride of ammonium is added to prevent the prema- 
 ture precipitation of magnesia, and should be added in con- 
 siderable quantity. A solution containing a salt of magnesia 
 yields, on addition of ammonia, a precipitate of hydrate of 
 magnesia, but if chloride of ammonium be previously added, 
 no precipitate is formed. 
 
 Should the chloride of ammonium itself produce a preci- 
 pitate, before the ammonia is added, it probably consists of 
 silica, and the substance under examination is likely to be 
 silicate of potash or soda (77, 80). 
 
 9. Should the precipitate produced by phosphate of soda 
 be flocculent instead of granular and crystalline, it is proba- 
 ably not caused by magnesium, but by aluminium or calcium 
 -which ought to have been detected in column 3 or 4. 
 
 In determining the particular form in which the magne- 
 sium is present in the substance under examination, assist- 
 ance will be derived from the following statements. 
 
 Metallic Magnesium, Mg, is silver-white, burns easily in 
 air, with a very brilliant light, and is dissolved, with effer- 
 vescence, when boiled with chloride of ammonium. 
 
 COMMON COMPOUNDS OF MAGNESIUM. 
 
 Names. Composition. 
 
 Calcined magnesia Magnesium, oxygen. 
 
 Common magnesia, or ) -. T 
 
 Basic carbonate of magnesia } Magnesia, carbonic acid, water. 
 
 Epsom salts, or. ) ,, 
 
 Sulphate of magnesia } Ma S nesia > sulphuric acid, water. 
 
 Magnesite, or ^ ) , r 
 
 Carbonate of magnesia Magnesia, carbonic acid. 
 
24 EXAMPLES FOR PRACTICE. 
 
 Calcined Magnesia, MgO, is a white earthy powder, in- 
 soluble in water, and dissolved by hydrochloric acid, with 
 little or no effervescence. 
 
 Basic Carbonate of Magnesia, 3MgC0 3 ,MgH 2 O 2 , is simi- 
 lar, but effervesces rapidly with hydrochloric acid. 
 
 Magnetite, MgCO 3 , is found in white earthy lumps which 
 dissolve, with effervescence, in hydrochloric acid. 
 
 Sulphate of Magnesia, MgS0 4 ,7Aq, forms needle-like 
 crystals, recognized by their bitter taste, easily dissolved by 
 water, and copiously precipitated by nitrate or chloride of 
 barium. 
 
 10. Examples for Practice in Table A The following 
 
 substances will afford good practice in this Table, especially 
 if they are presented to the student as puzzles, distinguished 
 only by letters or numbers. 
 
 Sulphate of magnesia 
 Sulphate of iron 
 Acetate of lead 
 Arsenious acid 
 Carbonate of lime 
 Sulphate of zinc 
 
 Corrosive sublimate 
 Sulphate of copper 
 Carbonate of magnesia 
 Sulpliide of antimony 
 Metallic tin. 
 
TABLE B. 
 
 25 
 
 o 
 S 
 
 & 
 
 ? 
 
 . .2 
 I 
 | 
 
 t 
 
 
 X .CJ 
 
 o 
 
 *< 
 o ^ 
 
 o x 
 
 
 II 
 
 bo 
 
 -S g 
 
 fl H 
 
 fv I-H 
 
 T^ 
 
 o 
 
 p 03 
 
 
 
 o r 3 
 
 O <rf 
 
 W fl 
 
 W .o 
 
 49 
 
 o 
 
 o 
 
 I 
 
 p 
 
 ^ ft 
 
 H 5 
 
 K O 
 H P4 
 
 H H 
 
 w 
 
 
 
 
 
 - 
 
 2s ^ 
 
 a 1*1 
 
 Tr S S J 
 
 2^5 A 
 - r/} o, o 
 
 ^^ ^ 3 
 
 5 - ' 
 
 II 
 
 I cS 
 
 >e 
 
 . 
 
 u -3 ^ fl 
 
 *' 
 
 -JS 
 
 !p 
 Ills 
 
 *e P- - S 
 
 ~ - S *^ .5 
 .: ^ '5 w J 
 
 g ft el o ce^ d 
 
 d 
 ceived 
 
26 SILVER AND ITS COMPOUNDS. 
 
 NOTES TO TABLE B. 
 
 12. Confirmatory Tests for Silver, to be applied to the 
 original solution. 
 
 Potash produces a brown precipitate of oxide of silver. 
 
 Bichromate of Potash produces a red precipitate of chro- 
 mate of silver. 
 
 Chloride of Ammonium produces a white precipitate of 
 chloride of silver. 
 
 If the original substance be Metallic Silver, Ag, it will be 
 recognized, partly by its external characters, partly by its 
 refusing to dissolve in hydrochloric acid, but dissolving easily 
 in nitric acid. If greater certainty be desired, it may be 
 examined by the blowpipe (2G4). 
 
 COMMON COMPOUNDS OF SILVER. 
 
 Names. Composition. 
 
 Nitrate of silver, or ) r\ ? c M 
 
 Lunar caustic } Oxule of Sllver ' mtnc acicL 
 
 Chloride of silver Silver, chlorine. 
 
 Nitrate of Silver, AgNO 3 , is sold either in flat, tabular, 
 transparent crystals, or in opaque cylindrical sticks made by 
 fusing the crystals. It is dissolved very readily by cold 
 water, and if filter-paper be moistened with the solution, and 
 exposed to light, especially to sunlight, it assumes a black 
 metallic appearance. 
 
 Chloride of Silver, AgCl, is insoluble in water and in 
 acids, and will therefore not come under consideration at 
 present (128). 
 
 13. Confirmatory Tests for Mercury as a mercurous com- 
 pound, to be applied to the original solution. 
 
 Potash produces a black precipitate of mercurous oxide, 
 Hg 2 0. 
 
 Metallic Copper becomes silvery from the deposition of 
 mercury. 
 
MERCURY AND ITS COMPOUNDS. 27 
 
 Protochloride of Tin (Stannous chloride), added in excess, 
 produces a gray precipitate of finely divided mercury. 
 Metallic Mercury (quicksilver) would be known at once. 
 
 COMMON MERCUROUS COMPOUNDS. 
 
 Names. Composition. 
 
 Mo_s chloride, or 
 
 Calomel, HgCl or Hg 2 Cl 2 , is commonly sold as a white 
 heavy powder, with a very slight shade of yellow. Before 
 being ground to powder, it forms a translucent fibrous mass. 
 It is not dissolved by water or dilute hydrochloric acid, and 
 not, unless boiled, by dilute nitric acid ; a mixture of the 
 two acids dissolves it more readily when boiled. Calomel 
 is easily known by its becoming black when shaken with 
 potash or with lime-water, and dark gray when shaken with 
 ammonia (250). 
 
 Protonitrate of Mercury, HgN0 3 ,Aq., is sold in transpa- 
 rent prismatic crystals, which are decomposed when treated 
 with water, a yellow basic nitrate of mercury being separated. 
 
 14. Confirmatory Tests for Lead, to be applied to the 
 original solution. 
 
 Hydrochloric Acid produces a white precipitate of lead 
 chloride, which dissolves on boiling, and is deposited in fine 
 needles on cooling. 
 
 Dilute Sulphuric Acid produces, especially on stirring, a 
 white precipitate of sulphate of lead, not dissolved by an 
 excess of the acid, and soon depositing as a powder at the 
 bottom of the tube. 
 
 Hydrosulphuric Acid produces a purplish black precipi- 
 tate of sulphide of lead. 
 
 Bichromate of Potash produces a yellow precipitate of 
 
28 
 
 LEAD AND ITS COMPOUNDS. 
 
 chromate of lead. If the original substance be Metallic Lead, 
 Pb, it will be recognized by its softness, and by its making 
 a black streak on paper ; it is insoluble in hydrochloric acid, 
 but dissolves when boiled with dilute nitric acid; the solu- 
 tion gives a white precipitate with excess of ammonia, and 
 a black precipitate, with a purplish shade, on addition of 
 hydrosulphuric acid. 
 
 COMMON COMPOUNDS OF LEAD. 
 
 Names. 
 
 Peroxide of lead, 
 
 } 
 
 Composition. 
 
 Lead,o Xyg en. 
 Lead, oxygen. 
 
 Carbonate of lead, or 
 White lead 
 
 Chroinate of lead, or 
 Chrome yellow 
 
 Nitrate of lead 
 Chloride of lead 
 Iodide of lead 
 Oxychloride of lead 
 Sulphate of lead 
 
 Sulphide of Ic^, or 
 
 ~ . -, f , -, n . ., 
 
 xlde of lead > carbonic acid, water. 
 
 /-v'-i riji -3 
 xlde of lead ' chromic acl(L 
 
 Oxide of lead, nitric acid. 
 
 Lead, chlorine. 
 
 Lead, iodine. 
 
 Lead, oxygen, chlorine. 
 
 Oxide of lead, sulphuric acid. 
 
 Lead; sulpllul , 
 
 Massicot, or Oxide of Lead, PbO, is a yellow powder, 
 which is insoluble in water, and becomes white when boiled 
 with hydrochloric acid, being converted into chloride of lead, 
 which partly dissolves, and is deposited in needle-like crys- 
 tals on cooling. Diluted nitric acid dissolves massicot when 
 gently heated. 
 
 Litharge is the same oxide of lead, which has been melted, 
 and is sold in pinkish-brown or buff scales or powder. The 
 action of water and acids upon it is similar to that upon 
 massicot. 
 
LEAD COMPOUNDS. 29 
 
 Minium, Pb 3 O 4 , is a bright red powder, which is not 
 affected by water, but evolves the smell of chlorine when 
 boiled with hydrochloric acid, and is slowly converted into 
 chloride of lead. Dilute nitric acid only partly dissolves it, 
 leaving a brown powder (peroxide of lead). 
 
 Peroxide of Lead, or Binoxide of Lead, PbO 2 , is a dark 
 brown powder, which is insoluble in water and in nitric acid, 
 but dissolves slowly in boiling hydrochloric acid, giving off 
 the smell of chlorine, and forming chloride of lead, which 
 crystallizes in needles from the solution as it cools. 
 
 Acetate of Lead, Pb2C 2 H 3 O 2 3Aq., forms white needle- 
 like crystals, which have a faint odor and an intensely sweet 
 taste. When treated with water it dissolves, but yields a 
 milky solution, especially with common water, from the 
 presence of a little carbonate of lead, formed from the car- 
 bonic acid contained in the water ; nitric acid clears it up at 
 once. When acetate of lead is heated on the point of a 
 knife, or on a slip of glass, it melts, and gives off an inflam- 
 mable vapor with a very peculiar smell, leaving a gray resi- 
 due composed of carbon and minute globules of metallic 
 lead, easily changing to yellow oxide of lead. 
 
 Perchloride of iron (ferric chloride), added to a solution 
 of acetate of lead, produces a white precipitate of chloride 
 of lead, and a red solution of ferric acetate, which is clearly 
 seen after the precipitate has subsided. 
 
 White Lead, or Basic Carbonate of Lead, 2PbCO 3 ,PbH 2 O 2 , 
 is a heavy earthy powder, soon becoming gray when exposed 
 to air, from the action of sulphuretted hydrogen. It is in- 
 soluble in water, and effervesces with hydrochloric acid, dis- 
 solving when heated, as chloride of lead, which crystallizes 
 in needles on cooling. Dilute nitric acid easily dissolves 
 carbonate of lead, with effervescence caused by the escape 
 of carbonic acid gas. When heated on a knife, or slip of 
 glass, it becomes yellow. 
 
 Chromate of Lead, PbCrO 4 , is commonly sold as a bright 
 yellow or orange red powder or cake (the orange chrome 
 
30 LEAD COMPOUNDS. 
 
 is the basic cliromate or dichromate of lead, PbCrO 4 ,PbO) ; 
 but fused cliromate of lead has a brown color. It is insolu- 
 ble in water, but dissolves slowly when boiled with strong 
 hydrochloric acid, evolving chlorine and yielding a green 
 solution. If it be heated with hydrochloric acid and a little 
 alcohol, a bright green solution of chlorides of chromium 
 and lead is produced, which deposits crystals of chloride of 
 lead on cooling. Nitric acid scarcely affects cliromate of 
 lead. If the yellow cliromate of lead be heated on a knife, 
 or slip of glass, its color changes to a red-brown. 
 
 Nitrate of Lead, Pb2NO 3 , forms hard white crystals, 
 having a sweet taste. It dissolves in water, but not easily 
 unless heated. When heated on a knife, or slip of glass, it 
 crackles or decrepitates violently. If previously powdered, 
 to prevent its flying off, it evolves suffocating brown fumes 
 (nitric peroxide), and leaves a yellow or red residue. 
 
 Chloride of Lead, PbCl 2 , is a white powder, sometimes 
 crystalline, which dissolves slowly when boiled with water, 
 the solution easily depositing crystals on cooling. 
 
 Iodide of Lead, PbI 2 , is a bright yellow powder, which 
 dissolves sparingly in boiling water, but more readily on 
 adding a little hydrochloric acid, yielding a colorless solu- 
 tion, which deposits brilliant golden scales on cooling. When 
 boiled with nitric acid, iodide of lead gives off the purple 
 vapors of iodine. 
 
 Oxychloride of Lead is either white (Pb 2 OCl 2 ) or bright 
 yellow (Pb 8 O 7 Cl 2 ), according to the mode of preparing it. 
 It melts easily when heated, the white oxychloride becoming 
 yellow. It is insoluble in water, but dissolves sparingly 
 when boiled with hydrochloric acid, the solution depositing 
 crystals of chloride of lead on cooling. 
 
 Sulphate of Lead, PbSO 4 , is a white powder, which does 
 not change when heated, is insoluble in water, but dissolves 
 slowly in boiling hydrochloric acid, the solution depositing 
 crystals of chloride of lead as it cools. 
 
 Sulphide of Lead or Galena, PbS, is a dark, gray, heavy, 
 
LEAD COMPOUNDS. 31 
 
 metallic -looking substance, the masses of which may be easily 
 split or cleaved with a knife-blade into rectangular fragments. 
 Water has no effect upon it, and diluted hydrochloric acid 
 very little, but nitric acid gradually dissolves it, brown fumes 
 being evolved, resulting from the decomposition of the nitric 
 acid. Strong hydrochloric acid also dissolves it on heating, 
 producing the offensive odor of hydrosulphuric acid. 
 Phosphate of Lead, Pb 3 2PO 4 , is described at (112). 
 
32 
 
 TABLE C. 
 
 1 
 
 I 
 
 I I 
 
 w 
 
 2 
 
 *C 
 
 W 
 
 <D 
 
 bD g 
 
 5 
 
 a 
 
 cd 
 
 CH 
 O 
 
 d 
 
 
 
 
 r-S . r S5 . ^i S.5B& ^ 
 
 
 
 
 
 C .., ^^ > 
 
 5 ^ ^5 
 
 ||||ggi-|*^ | 
 
 
 
 
 
 S;"? S ? 
 
 M'S^Js^'Cp*: *"*' ^ 
 
 
 
 s 
 
 S 
 
 
 &st? 
 
 a ^ ni ? 
 
 ^||op||^|g 2 
 
 IOSULPHURIC ACID. 
 
 
 r Orange-red. f 
 ? of Atnimoiiy. Ttisulplride of 
 
 BONATE OF AMMONIA (32). 
 
 Undissolved. 
 
 Ora 
 Sulphide 
 Probabl. 
 Antimf. 
 
 fl^fljf 1 
 
 
 Hsmuth or Mercury. 
 
 YDROCHLORIC ACID, 
 
 ree parts. 
 
 " 11 * S -1 -2* 
 
 ^ M M 
 
 < fc _ .2 ^ ^ 22 
 
 * ^ S " 1 ^ 
 1-3 ?S| 1^ 
 
 i r ellow. 
 of Tin. Probable 
 ' Tin, as a stannic 
 mud (36, 37). 
 
 r-( 
 
 
 W ri K 
 
 Its 
 
 
 ^0 ft 
 
 S o ^ 
 
 
 
 to^S - 
 
 "Ii^i~ ^ 
 
 K 
 S 
 
 J 
 
 " ^ ."S 
 > 
 
 E ;> 
 
 
 g u 
 
 - H 
 
 
 
 ill 
 
 f f" C* 1- ? S tS ' 
 
 o =2 - g 23 
 
 DUCED 
 
 C 
 
 8 
 
 of A r sent 
 precipita 
 
 
 CO CJ 
 
 a 
 
 cc T'"'^ 
 
 : t T3 
 
 I* " 
 
 "SSftim^S 1 "s^ 
 
 S * i = - S i. 2 7 "3 
 ^^ g 
 
 S J^ 
 
 C 
 
 zt 
 
 
 
 Ir 1.^12- 
 
 o 
 
 if 
 
 ^ t^S*" Ss"2 
 
 3. IK * ;F 
 
 p 
 
 -* ' 
 
 8, "o 's' P< "2. 
 
 **< 
 
 t--. '" 
 
 oo O "S -= ^ 
 
 H 
 
 . 
 
 % o 
 
 , EL5_ 
 
 S ^ * x 
 
 *"! 
 
 -^^ 
 
 "* -*- (^ "^ *5 
 
 
 
 
 5 -S %^ ^ rc p s* ^ 
 
 H 
 
 'S 
 
 |f 
 
 
 
 *" ** r -** "^ ^ 
 
 
 s 
 
 
 
 
 SfSfSg 1 
 
 
 
 .; 
 
 K L 
 
 
 C &* 
 
 ^ ? 1 1 1 " M '^ 
 
 S 
 
 H 
 
 E '? 
 
 
 a> 
 
 ^ ^ ^^ '- 2 J 
 
 r^ 
 
 
 ~ j. rt 
 
 
 FH 
 
 <, S H ^' 3 
 
 > 
 
 
 
 . u K 
 
 H 
 
 
 S|; "3 
 
 5 2^ 
 
 h 
 
 
 ^ S 1 
 
 S" S, K 1 ^ 2 ^ " 
 
 
 
 
 S ^ * 
 
 5j5 < ^-^^|2'p<*a g ^2 
 
 NATION 
 
 
 g t 1 
 
 2 1 i S 
 
 fc -S 1 v o 
 
 s * 4 J 3 
 
 111 
 
 - 
 
 
 5 *o 
 
 5|| Ix 1 1 1 1 21 Hi 
 
 ^ 
 
 
 _* ^ J^ ^ 
 
 o^^'^SK-S^-^ f^*" 1 
 
 r^ 
 
 
 w S^ S "s g 
 
 ^ S S 3 * S c^ 
 
 ^ 
 
 
 K S o 
 
 E l. _ .1^ 
 
 d 5 | 
 
WASHING PRECIPITATES. 
 
 33 
 
 Fid. 12. 
 
 Fia. 14. 
 
 FIG. 13. 
 
 EXPLANATIONS AND INSTRUCTIONS ON 
 TABLE C. 
 
 16. To wash a precipitate. The precipitate having been 
 collected upon a filter (4) may be washed by filling the filter 
 twice or thrice with distilled water, and allowing it to run 
 
 through. A washing-bottle (fig. 12) 
 will be of great assistance in washing 
 precipitates, the stream of water be- 
 ing directed so as to wash the pre- 
 cipitate from the sides towards the 
 apex of the filter. 
 
 When a precipitate is very heavy 
 and subsides readily, it may be 
 washed by decapitation that is, by 
 Washing-bottle. s } ia ^i n g j t U p w i t h successive quan- 
 tities of distilled 
 water, which are 
 poured off when 
 the precipitate has 
 settled down. A 
 wet glass rod, held 
 against the lip of the 
 test-tube (fig. 13), 
 greatly assists in de- 
 canting the liquid without disturbing the precipitate. 
 
 17. Heating solid substances in tubes Ordinary 
 test-tubes should not be used for this purpose, but 
 much smaller tubes, which are made, with the help 
 of the blowpipe, from a piece of (German) glass 
 tube free from lead, of the size represented in fig. 14. 
 The middle of this piece of tube is softened in the 
 blowpipe flame (fig. 15), and quickly drawn out to 
 form two tubes connected by a mere thread of glass, 
 which is then detached from each tube, as shown at 
 , leaving the finished tube of the shape shown at b. 
 
34 
 
 SOLIDS HEATED IN TUBES. 
 
 FIG. 15. 
 
 FIG. 16. 
 
 The substance to be heated is introduced into this tube, in 
 very small quantity, and the sides of the tube are cleansed 
 
 frc m adhering particles by 
 rubbing them with a match. 
 A strap of folded paper (fig. 
 16) is put round the tube, 
 which is then held in the 
 lower part of the flame of a 
 gas-jet (to avoid smoking it), 
 or in a spirit-flame. If any 
 moisture should condense on 
 the sides of the tube., incline 
 
 its mouth downwards, so that the drops may not run back 
 upon the heated glass and crack it. If it be necessary to 
 apply a more intense heat, the blowpipe flame may be 
 directed on to the bottom of the tube. 
 
 18. To ascertain ivhether a solution is alkaline or acid, 
 
TIN IDENTIFIED. 35 
 
 dip a piece of red or blue litmus-paper into it, or touch the 
 paper with a glass rod dipped in the liquid. An alkaline 
 solution changes red litmus to blue, whilst an acid solution 
 reddens the blue litmus-paper. In the absence of test- 
 paper the taste may of course be relied on for a rough 
 indication. 
 
 NOTES TO TABLE C. 
 
 19. Lead is liable to be found in the precipitate produced 
 by hydrosulphuric acid, because its chloride is dissolved to a 
 considerable extent by water, so that a weak solution of a 
 salt of lead is not precipitated by hydrochloric acid. 
 
 20. The mercuric salts generally give, on addition of a 
 little hydrosulphuric acid, a yellow or brownish precipitate, 
 which passes through various shades on adding more hydro- 
 sulphuric acid, finally becoming black. 
 
 21. Solutions of copper have a blue or green color. The 
 blue solutions are turned green by hydrochloric acid. 
 
 22. The perchloride of mercury (mercuric chloride) will 
 give, with stannous salts or protosalts' of tin, a white precipi- 
 tate of mercurons chloride (calomel) or a gray precipitate 
 of finely-divided metallic mercury, accordingly as one-half 
 or the whole of the chlorine is abstracted from the mercuric 
 chloride by the protosalt of tin. 
 
 23. Metallic Tin, Sn, would be easily known by its be- 
 coming converted into a white powder (binoxide of tin) when 
 boiled with nitric acid. It dissolves slowly when boiled with 
 diluted hydrochloric acid, and rapidly in the strong acid 
 yielding a solution of protochloride of tin (or stannous chlo- 
 ride), which is at once recognized by the test with perchlo- 
 ride of mercury mentioned above (22). 
 
 For the common protosalts of tin, see the next page. 
 
36 TIN COMPOUNDS. 
 
 COMMON STANNOUS COMPOUNDS, OR PKOTOSALTS OF TIN. 
 
 Names. Composition. 
 
 Protocliloride of tin or ) rp . , , . 
 
 Salts of tin, or tin crystals } * in ' clllorin e, water. 
 
 Protosulpliide of tin, or ) m . 
 
 Tin pyrites j lm ' sulphur. 
 
 Protochloride of Tin, SnCl 2 ,2Aq., usually forms needle- 
 like crystals with a tinge of yellow. Water decomposes it, 
 forming a milky-white oxychloride of tin. Hydrochloric acid 
 dissolves it entirely. 
 
 Tin Pyrites, SnS, is a dark gray mineral which is slowly 
 dissolved when boiled with hydrochloric acid, evolving the 
 smell of hydrosulphuric acid. Boiling nitric acid converts it 
 into the white binoxide of tin. 
 
 24. The precipitate of sulphate of lead sometimes forms 
 only after the lapse of some minutes in highly acid solutions. 
 
 25. If the quantity of the original solution is very limited, 
 ammonia may be added in excess to that portion which has 
 been already tested with sulphuric acid. 
 
 26. The presence of copper may be confirmed by intro- 
 ducing a piece of clean iron or steel into this solution mixed 
 with a slight excess of hydrochloric acid ; a red coating of 
 metallic copper will be deposited upon the metal. 
 
 Ferrocyanide of potassium may be added to the original 
 solution ; if copper is present, a red-brown precipitate of 
 ferrocyanide of copper will be produced. 
 
 27. Metallic Copper, Cu, is identified by its color, its 
 insolubility in diluted hydrochloric acid, and by its dissolv- 
 ing rapidly in nitric acid, to a green or blue solution of 
 nitrate of copper. 
 
COPPER COMPOUNDS. 37 
 
 COMMON COMPOUNDS OF COPPER. 
 
 Names. Composition. 
 
 Sulphate of copper, or ) Oxide of copper, sulphuric acid, 
 
 Blue-stone ) water. 
 
 Arsenite of copper, or ) Oxide of copper, arsenious acid, 
 
 Scheele's green ) water. 
 
 Basic acetate of copper, or ) Oxide of copper, acetic acid, 
 
 Verdigris ) water. 
 
 Basic carbonate of copper, or ) Oxide of copper, carbonic acid, 
 
 Malachite ) water. 
 
 Oxy chloride of copper, or ) Oxide of copper, chloride of cop- 
 
 Brunswick green ) per, water. 
 
 Copper, oxygen. 
 
 Sulphide of copper Copper, sulphur. 
 
 Sulphate of Copper, CuSO 4 ,H 2 O,4Aq., forms blue dia- 
 mond-shaped crystals, often grouped into irregular masses. 
 It dissolves easily in water, yielding a blue solution, which 
 is copiously precipitated by nitrate or chloride of barium. 
 Dried sulphate of copper is nearly white, and becomes blue 
 when moistened. 
 
 Arsenite of Copper, CuHAs0 3 , is a bright green powder, 
 insoluble in water, but soluble in hydrochloric acid to a 
 green liquid. It may be tested for arsenious acid according 
 to (33). 
 
 Verdigris, Cu2C 2 H 3 O 2 ,CuO,6H 2 O, has a bluish green 
 color. It is partly dissolved by water, and entirely by hy- 
 drochloric acid, to a green solution. When heated on a 
 knife or a slip of glass, it is blackened and emits an odor 
 like that of vinegar. 
 
 The Basic Carbonates of Copper are blue (2CuC0 3 ,Cu 
 H a O 2 ) or green (CuCO 3 ,CuH 2 O 2 ), insoluble in water, but 
 soluble, with effervescence, in hydrochloric acid. 
 4 
 
38 BISMUTH CONFIRMED. 
 
 Oxychloride of Copper, Cu 4 Cl. 2 O 3 ,4Aq., is green. It is 
 insoluble in water, but dissolves in acids. Its solution in 
 nitric acid may be tested for chlorine with nitrate of silver 
 (Table H). 
 
 Cnpric Oxide, CuO, is a black powder, insoluble in water, 
 but soluble in hydrochloric acid, on boiling, forming a green 
 solution, which sometimes becomes turbid when mixed with 
 water, from the separation of a little subchloride of copper. 
 
 Cuprous Oxide, Cu 2 O, is red or red-brown; it is not dis- 
 solved by water, but hydrochloric acid dissolves it, on boil- 
 ing, to a brown solution, which gives a thick white precipi- 
 tate of cuprous chloride (subchloride of copper) when 
 mixed with water. Boiling nitric acid dissolves cuprous 
 oxide, forming a blue solution which is not precipitated by 
 water. 
 
 Sulphide of Copper, Cu 2 S, as found in nature (cuprous 
 sulphide or copper-glance), is a black substance with a some-,, 
 what metallic lustre ; insoluble in water and in hydrochloric 
 acid, but dissolved by boiling in nitric acid to a blue solution, 
 spongy flakes of dark colored sulphur usually separating. 
 
 The artificial sulphide of copper, CuS, is usually a black 
 powder with a shade of green, which behaves in the same 
 way. 
 
 28. If the precipitate of oxide of bismuth, Bi 2 O 3 , pro- 
 duced by ammonia be small, it should be collected upon a 
 filter, washed with a little water (1G), and very carefully 
 dissolved by dropping two or three drops of diluted hydro- 
 chloric acid upon it. When water is added to the slightly 
 acid solution of chloride of bismuth so produced, a milky 
 precipitate of oxychloride of bismuth is formed, but the 
 presence of an excess of acid prevents its formation. 
 
 To confirm the presence of bismuth, add to the original 
 solution (or to the solution of the oxide precipitated by am- 
 inonia, in hydrochloric acid, even after dilution) solution 
 of iodide of potassium; this will produce a red or yellow 
 color if bismuth be present (or even, in a strong solution, a 
 
BISMUTH COMPOUNDS. 39 
 
 brown precipitate of iodide of bismuth), and on adding a 
 drop of acetate or nitrate of lead, the iodide of lead which 
 precipitates will have a brown or red instead of its usual 
 yellow color, from the presence of iodide of bismuth. If 
 this precipitate be dissolved by heating the liquid and add- 
 ing a few drops of dil. hydrochloric or acetic acid, it will 
 crystallize out in very beautiful brown or red scales as the 
 solution cools. 
 
 An excellent confirmatory test for bismuth consists in 
 adding to the original solution some protochloride of tin 
 (stannous chloride, prepared by boiling a fragment of tin 
 with strong hydrochloric acid) and an excess of potash, when 
 a black precipitate of bismuthous oxide, BiO, is obtained. 
 Should the stannous chloride produce a gray or white pre- 
 cipitate, becoming dark gray on adding potash, it is probably 
 due to the presence of mercury. 
 
 29. Metallic Bismuth, Bi, is a brittle metal with a faint 
 pink reflection. It does not dissolve in hydrochloric acid, 
 but dissolves in diluted nitric acid, on boiling. 
 
 COMMON COMPOUNDS OF BISMUTH. 
 
 Names. Composition. 
 
 Basic nitrate of bismuth, or ) Oxide of bismuth, nitric acid, 
 Flake white $ water. 
 
 Oxychloride of bismuth, or ) Oxide of bismuth, chloride of bis- 
 Pearl white ) muth, water. 
 
 Flake white,* Bi 2 N 2 8 .H 2 0, is insoluble in water, but 
 dissolves in hydrochloric acid. When heated in a dry glass 
 tube (17), it evolves moisture, which condenses in drops 
 on the cool part of the tube, and brown vapors of nitric 
 peroxide. 
 
 Pearl white, B1OC1, is also insoluble in water and soluble 
 
 * Flake white sometimes consists of basic carbonate of lead 
 (white lead). 
 
40 MERCURY COMPOUNDS. 
 
 in hydrochloric acid. It may be dissolved in nitric acid, and 
 tested for chlorine with nitrate of silver (Table H). 
 
 30. In order to be quite sure of the presence of mercury 
 in a solution, it must be boiled with metallic copper. If 
 nitric acid be present, which would dissolve the copper, it 
 must be neutralized by adding a slight excess of ammonia 
 (5) ; enough dilute hydrochloric acid must then be added to 
 destroy the odor of ammonia, even after shaking, and two 
 or three slips of bright copper introduced. On boiling, the 
 copper will acquire a bright silvery coating, and if it be 
 rinsed with water, dried in filter-paper and heated in a dry 
 tube (17), a gray crust of minute globules of mercury will 
 be formed upon the side of the tube, uniting into larger 
 globules when rubbed with a glass rod or a wooden match. 
 Bismuth also deposits upon the copper, but forms a dull gray 
 coating. 
 
 When mercury is present in the form of cyanide of mer- 
 cury, it would generally escape detection until the boiling 
 with hydrochloric acid and copper, at the end of Table C. 
 
 31. COMMON MERCURIC* COMPOUNDS. 
 
 Na mes. Co?npositio n . 
 
 Mercuric chloride, or perchloride, or 
 
 Bichloride of mercury, or Mercury, chlorine. 
 
 Corrosive sublimate 
 
 Mercuric sulphide, or ) 
 
 Vermilion, or cinnabar $ 
 
 Mercurv snlnhnr 
 my ' Sulphl 
 
 Mercuric oxide, or ) ,, 
 
 Nitric oxide of mercury \ Mercury, oxygen. 
 
 White precipitate \ Mercury, chlorine, nitro- 
 
 gen, hydrogen. 
 
 Mercuric iodide Mercury, iodine. 
 
 Mercuric cyanide 
 
 Mercury, cyanogen (car- 
 bon, and nitrogen). 
 
 * Nitric acid converts mercurous compounds into mercuric com- 
 pounds ; hence, if this acid should have been used to dissolve the 
 original substance, the latter may possibly have been a mercurous 
 
MERCURY COMPOUNDS. 41 
 
 Corrosive Sublimate, HgCl 2 , is sold either in shining white 
 semi-transparent masses or as a white crystalline powder. It 
 dissolves readily when boiled with water, and crystallizes 
 from a strong solution in white needles. When heated in a 
 small tube (17), it melts very easily to a perfectly clear 
 liquid, which crystallizes in fine needles on cooling. By 
 continuing the heat, it is boiled away in vapor which has a 
 fearfully suffocating effect upon the nose. 
 
 Vermilion, HgS, is known by its bright red color. It is 
 insoluble in water, and in hydrochloric or nitric acid sepa- 
 rately, but it dissolves in a mixture of the two acids, with 
 separation of spongy flakes of sulphur. 
 
 Cinnabar, HgS, the chief ore of mercury, is generally met 
 with in dark brown very heavy hard masses, which become 
 red when scraped with a knife. In its relation to solvents 
 it resembles vermilion. 
 
 Nitric Oxide of Mercury, HgO, is a bright red shining 
 powder, insoluble in water, but soluble in hydrochloric acid. 
 
 White Precipitate, HgClNH 2 , is a heavy white earthy- 
 looking substance, insoluble in watec, but soluble in hydro- 
 chloric acid. When boiled for some time with water, it 
 becomes yellow. On boiling it with potash, it evolves the 
 odor of ammonia. 
 
 Mercuric Iodide, or Biniodide of Mercury, HgI 2 , is a 
 scarlet powder, insoluble in water, but dissolved by boiling 
 hydrochloric acid. When heated on a slip of glass, it be- 
 comes bright yellow, and passes off in yellow fumes. The 
 yellow powder becomes red when rubbed with a glass rod. 
 
 Mercuric Cyanide, or Cyanide or Bicyanide of Mercury, 
 Hg2CN, forms white prismatic crystals which dissolve in 
 boiling water. When heated in a dry tube (17) they 
 crackle, melt, and evolve cyanogen, which may be recog- 
 nized by its odor and by its burning with a pink flame. A 
 brown residue is left at the bottom of the tube, and the 
 cooler part of the tube is covered with a gray deposit of mer- 
 cury which unites into globules when rubbed with a match. 
 
42 REINSCIl'S AND MAKSIl's TESTS FOR ARSENIC. 
 
 32. The carbonate of ammonia is to be added in excess, 
 so that the smell of ammonia is quite perceptible on warming 
 the liquid ; otherwise the sulphide of arsenic would not be 
 dissolved and might be mistaken for that of tin. 
 
 It is better to collect a little of the precipitate upon a filter, 
 to wash it once or twice with water (16), and to pour some 
 warm carbonate of ammonia over it. If there be any doubt 
 whether the precipitate has been dissolved, test a little of the 
 solution in carbonate of ammonia with excess of hydrochloric 
 acid, when sulphide of arsenic will be separated in yellow 
 flakes. 
 
 33. Should any confirmatory test be required for arsenic, 
 either Reinsch's test or Marsh's test may be employed. 
 
 fieinsch's test for arsenic Boil a little of the original 
 
 substance with excess of hydrochloric acid and a few strips 
 of bright copper for a minute or two. The copper displaces 
 the arsenic from the solution, and a dark gray compound 
 of arsenic with copper is formed upon the surface of the 
 strips. Rinse these with a little water, dry them on filter- 
 paper, and heat them gently in a 
 small tube closed at one end (17) ; 
 minute shining crystals of arsen- 
 ious acid will be deposited on 
 the cool part of the tube, having 
 been produced by the combination 
 of the arsenic with oxygen from 
 the air. If the crystalline deposit 
 is examined with the microscope 
 (for which purpose the binocular 
 is to be preferred), it will be seen 
 to consist of octahedral crystals (fig. 17). 
 
 34. Marsh's test for arsenic. Dissolve the substance, if 
 possible, in water or hydrochloric acid. If it be insoluble in 
 these, dissolve it in nitric acid, evaporate the solution to dry- 
 ness in a small dish, and redissolve the residue in water with 
 
 o littlo Kir/lr/wtliWif on^rl 
 
MARSH'S TEST FOR ARSENIC. 
 
 43 
 
 Arrange an apparatus as represented in 
 fig. 18 ; the funnel-tube A, and the bent 
 tube (229) B, being passed through air-tight 
 perforated corks (228). B has been drawn 
 out to a moderately fine jet by softening it 
 in the blowpipe flame (fig. 15), drawing it 
 out to a narrow neck (fig. 19), and cutting 
 this across with a file, at a. 
 
 FIG. 19. 
 
 FIG. 18. 
 
 Introduce into the bottle enough granulated zinc* to cover 
 the bottom, fill the bottle about one-third with water, and 
 pour in dilute sulphuric acid, through the funnel-tube (the 
 lower end of which must dip beneath the water) until mode- 
 rate effervescence, from the evolution of hydrogen gas, takes 
 place. Keep the tube as far away from a flame, because the 
 bottle is now filled with an explosive mixture of hydrogen 
 and air. Incline the gas-bottle and hold a small test-tube 
 over the tube ft, as represented in fig. 20, for about a minute, 
 slowly withdraw it, keeping its mouth downwards, and apply 
 it .to a flame ; if it explodes, the hydrogen in the bottle is still 
 
 FIG. 20. 
 
 FIG. 21. 
 
 * To granulate zinc, melt it in an iron ladle, stand upon the 
 
44 ARSENIC IDENTIFIED. 
 
 mixed with air, and it would explode if lighted. Repeat the 
 experiment until the hydrogen can be seen to burn steadily 
 away in the test-tube. The hydrogen issuing from the tube 
 B may then be kindled with safety. Hold the lid of a porce- 
 lain crucible in the flame (fig. 21), pressing it close up to 
 the jet. No spot (of arsenic or antimony) will be deposited 
 upon the porcelain if the hydrogen be pure. 
 
 Pour a few drops of the solution to be tested for arsenic, 
 prepare as directed above, into the funnel-tube A, and re- 
 peat the experiment with the porcelain lid. If arsenic be 
 present, arsenietted hydrogen will be formed, and will de- 
 posit a dark brown stain of arsenic on the porcelain surface. 
 Make a stain upon another lid in the same way. 
 
 Heat the tube B with a spirit-lamp 
 FIG. 22. (fjg e 22) for a minute or two, when the 
 
 arsenietted hydrogen will be decom- 
 posed, and a nearly black shining crust 
 of arsenic will be deposited on the cooler 
 part of the tube. 
 
 To prove that these results are due 
 to arsenic, and not to antimony, which 
 might imitate them, touch one of the 
 stains with a glass rod dipped in solu- 
 tion of chloride of lime, which will dissolve a stain of 
 arsenic, but not that of antimony. 
 
 Test the other stain in the same way with yellow hydro- 
 sulphate of ammonia, which will not dissolve a stain of 
 arsenic, but dissolves that of antimony. If the deposit formed 
 in B were due to antimony, it would be produced close to the 
 hot part of the tube, whilst the arsenical crust is deposited 
 upon the cooler part of the tube. To be quite sure of its 
 character, make a deep file-mark at each end of it, and break 
 off the end of the glass. Wrap the piece containing the 
 deposit in a piece of stout paper, break it into fragments 
 (not into powder), and heat one or two of these in a small 
 tube (17), when the arsenic will be oxidized, and a shining 
 
ARSENICAL COMPOUNDS. 45 
 
 ring of crystals of arsenious acid will be deposited on the 
 cooler part of the tube. 
 
 35. Metallic Arsenic, As, is a dark gray brittle substance, 
 with metallic lustre. It is insoluble in water and in hydro- 
 chloric acid, but dissolves in boiling nitric acid. When 
 heated in air, it emits a smell of garlic. Heated in a dry 
 tube (17) it is converted into vapor, which condenses higher 
 up the tube, partly as a black shining crust, partly as a 
 white crystalline powder of arsenious acid produced by the 
 oxygen of the air in the tube. 
 
 COMMON COMPOUNDS OF ARSENIC. 
 
 Names. Composition. 
 
 Arsenite of copper, or ? A -j -j * 
 
 Scheele's green \ Arsenious acid, oxide of copper. 
 
 Arsenic acid Arsenic, oxygen. 
 
 Arseniate of soda Arsenic acid, soda, water. 
 
 Tersulpliide of arsenic, or ) A . , , 
 
 Yellow orpiment j Arsemc ' sul P lmr ' 
 
 Bisulphide of arsenic, or 
 Realgar or red orpiment 
 
 A . 
 Arsemc > 
 
 Iodide of Arsenic Arsenic, iodine. 
 
 Arsenious Acid, As 2 3 , is sold either in opaque porcelain- 
 like masses, or as a white powder. It seems insoluble in 
 water, unless long boiled with it, but dissolves in boiling 
 hydrochloric acid, and more readily in boiling nitric acid, 
 evolving from the latter brown fumes of nitrous acid. 
 
 When a little arsenious acid is heated in a dry tube (17), 
 it is entirely converted into vapor, and is deposited on the 
 cooler part of the tube as a white crystalline powder (24G, 
 251). 
 
 Arsenite of Copper has been described at page 37. When 
 
46 AUSENICAL COMPOUNDS. 
 
 heated in a dry tube (17), it evolves vapor of arsenious acid 
 Avhich condenses to a crystalline powder. 
 
 Arsenic Acid, As 2 O 5 , is commonly sold in combination 
 with water, as hydrated arsenic acid, in white irregular lumps, 
 which soon become damp by absorbing water from the air. 
 It dissolves in water, and if the solution be mixed with 
 hydrochloric acid, and a considerable volume of hydro- 
 sulphuric acid added, it is not precipitated in the cold, but 
 when boiled it yields a white precipitate of sulphur, followed 
 by a yellow precipitate of tersulphide of arsenic. 
 
 Arseniate of soda, Na,HAsO 4 .7Aq., forms prismatic crys- 
 tals which dissolve easily in water, yielding a solution which 
 is alkaline to test-papers (18), and behaves like arsenic acid 
 with hydrochloric and hydrosulphuric acids. 
 
 The solution of arseniate of soda gives a red-brown pre- 
 cipitate with nitrate of silver, and the solution of arsenic acid 
 will give the same precipitate if ammonia be very cautiously 
 added after the nitrate of silver. 
 
 Tersulphide of Arsenic, As 2 S 3 , is bright yellow, insoluble 
 in water and in hydrochloric acid, but dissolved by boiling 
 nitric acid, with separation of sulphur. It dissolves in warm 
 ammonia, or potash, yielding a colorless s6lution, from which 
 it is reprecipitated in yellow flakes by an excess of hydro- 
 chloric acid. 
 
 Realgar, As 2 S 2 , is sold in orange-red masses or powder. 
 It behaves like the preceding with water and acids, but is not 
 entirely dissolved by potash, leaving a dark brown residue. 
 
 Iodide of Arsenic, AsI 3 , forms brick-red flakes which are 
 dissolved to a considerable extent by boiling water, and 
 evolve violet vapors when boiled with nitric acid. 
 
 36. If too little carbonate of ammonia be added, the 
 sulphide of arsenic may be mistaken for bisulphide of tin. 
 On adding ammonia, the sulphide of arsenic dissolves very 
 readily, but the bisulphide of tin dissolves with difficulty. 
 
 To confirm the presence of tin, place in a little of the 
 original solution (which should contain free hydrochloric but 
 
TIN COMPOUNDS. 47 
 
 not nitric acid) a piece of zinc ; after a short time metallic 
 tin will be deposited as a spongy mass; rinse this with water, 
 boil it with a little hydrochloric acid to dissolve it in the 
 form of chloride of tin (stannous chloride), and test it with 
 perchloride of mercury (22). 
 
 If the original solution contains nitric acid, add ammonia 
 in slight excess to neutralize it, and acidify the solution again 
 with hydrochloric acid before testing with zinc. 
 
 37. The mode of identifying metallic tin has been de- 
 scribed at (23). 
 
 COMMON STANNIC COMPOUNDS (OR PERSALTS OF TIN.)* 
 
 Names. Composition. 
 
 Binoxide of tin, or ) m . 
 
 Stannic acid ) Tin, oxygen. 
 
 Stannate of soda Stannic acid, soda, water. 
 
 Bisulphide of tin ) m . 
 
 Aurum musivum Tin > sulphur. 
 
 Stannic chloride, or ) 
 
 Nitromuriate of tin f Tm ' chlorine (water). 
 
 Stannic chloride. 
 Hydrochlorate of ammonia. 
 
 Pink salt | Stannic chloride. 
 
 Binoxide of Tin, SnO 2 , is insoluble in water and acids 
 and will, therefore, not be considered at present. 
 
 Stannate of Soda, Na 2 SnO 3 .4Aq., is usually sold in opaque 
 irregular crystals, which are soluble in cold water, though 
 generally leaving a white residue. The solution is alkaline 
 (18). Hydrochloric acid added drop by drop causes a white 
 precipitate of stannic acid, which is redissolved by an excess 
 of the acid. 
 
 Bisulphide of Tin, SnS 2 , or bronze powder, or Mosaic 
 
 * Nitric acid converts stannous compounds into stannic com- 
 pounds ; hence, if this acid has been used to dissolve the original 
 substance, this may have been a stannous compound (23). 
 
48 TIN COMPOUNDS. 
 
 gold, is a golden yellow, scaly substance, insoluble in water, 
 in hydrochloric acid, and in nitric acid, but dissolved by 
 boiling with hydochloric acid and adding a little nitric acid. 
 Much nitric acid causes the separation of white binoxide of 
 tin. 
 
 Stannic Chloride, SnCl 4 , is commonly met with in the 
 state of solution, which is highly acid to test-papers (18). 
 It may be tested for chlorine with nitrate of silver (Table H). 
 
 Pink Salt, SnCl 4 .2NH 4 Cl, may be tested for chlorine in 
 a similar manner. When heated with potash it evolves 
 ammonia. 
 
 38. The presence of antimony may be confirmed by 
 acidifying the original solution with hydrochloric acid, and 
 introducing a piece of zinc, when a sooty black powder of 
 metallic antimony will be deposited. 
 
 Or a few drops of the solution (free from nitric acid) 
 acidified with hydrochloric acid, may be placed upon a 
 surface of platinum (foil) and a piece of zinc made to touch 
 the platinum ; a dark stain of antimony will be formed upon 
 the latter metal. If this stain be rinsed with water, and 
 wetted with yellow hydrosulphate of ammonia, it will be 
 dissolved on warming, and the solution, if evaporated on the 
 platinum, will deposit the orange-colored sulphide of anti- 
 mony. 
 
 Or the solution, containing hydrochloric acid only, and not 
 nitric acid, may be tested by Marsh's test (34). 
 
 Or a little of the original substance may be boiled with 
 excess of hydrochloric acid, and a few strips of copper, when 
 the latter will displace the antimony and become covered 
 with a purple antimonial film. 
 
 39. Metallic Antimony, Sb, is known by its great brittle- 
 ness and brilliant lustre. It is not attacked by water, and to 
 a slight extent only by boiling hydrochloric acid. When 
 boiled with diluted nitric acid, it is converted, though slowly, 
 into a white powder (antimonic acid) which is slightly 
 soluble in the nitric acid. A mixture of hydrochloric acid 
 
ANTIMONY COMPOUNDS. 49 
 
 with a little nitric acid dissolves the metal, and if a large 
 excess of acid be avoided, the addition of a large volume of 
 water to the solution causes a thick white precipitate of oxy- 
 chloride of antimony. 
 
 COMMON COMPOUNDS OF ANTIMONY. 
 
 Names. Composition. 
 
 Tersulphide of antimony, or ) 
 
 Crude antimony ore ] Antimony, sulphur. 
 
 Teroxide of antimony ) ... 
 
 Flowers of antimony } Antimony, oxygen. 
 
 Tartar emetic -J Teroxide of antimony. 
 
 I Potash, tartaric acid, water. 
 
 Terchloride of antimony Antimony, chlorine. 
 
 Antimoniate of potash Aiitimonic acid, potash. 
 
 Tersulphide of Antimony, Sb 2 S 3 , as found in nature, is a 
 dark gray crystalline substance with decidedly metallic 
 lustre. It is unaffected by water, but boiling hydrochloric 
 acid dissolves it slowly, evolving the. odor of hydrosulphuric 
 acid. If the solution thus obtained be filtered and mixed 
 with water, it generally gives an orange-red precipitate. A 
 mixture of hydrochloric acid with a little nitric acid dis- 
 solves it readily, flakes of sulphur being separated. 
 
 The artificial tersulphide of antimony, or antimony-ver- 
 milion, is an orange red powder, which behaves with acids 
 like the native tersulphide. 
 
 Teroxide of Antimony, Sb 2 O 3 , is a grayish-white powder, 
 insoluble in water, but dissolved by hydrochloric acid. When 
 heated on a knife or a slip of glass, it becomes yellow, but 
 turns white again on cooling. 
 
 Tartar-emetic 2(K.SbO.C 4 H 4 O 6 ).Aq., forms hard white 
 
 crystals, or a white powder, readily dissolved by hot water. 
 
 The solution gives a white precipitate of teroxide of antimony 
 
 on adding a drop of diluted hydrochloric acid, but an excess 
 
 5 
 
50 ANTIMONY COMPOUNDS. 
 
 of acid readily dissolves it. When tartar-emetic is heated 
 on a knife or a slip of glass it is carbonized, and evolves the 
 peculiar odor of burnt sugar, which characterizes the pro- 
 ducts of decomposition of tartaric acid. 
 
 Terchloride of Antimony, SbCl 3 , in the pure state forms a 
 soft gray fusible solid, but it is commonly met with in the 
 state of solution, usually of a yellow color, due to the pres- 
 ence of iron. When largely diluted with water, it gives a 
 white precipitate of oxychloride of antimony. 
 
 Antimoniate of Potash, KSbO 3 , is usually sold as a white 
 powder, which is partly dissolved by boiling water, yielding 
 an alkaline solution (18). If this solution be filtered, and a 
 drop of diluted hydrochloric acid added to it, it yields a slight 
 white precipitate of antimonic acid, which dissolves in an 
 excess of the acid. If a drop of the aqueous solution be 
 briskly stirred, on a slip of glass, with a drop of solution of 
 carbonate of soda, it gives a precipitate (antimoniate of soda) 
 which deposits on the lines where the rod has rubbed against 
 the glass. 
 
 40. Examples for Practice in Tables 13 and O. The 
 following substances may be selected (10) : 
 
 Corrosive sublimate, 
 Acetate of lead, 
 Sulphate of copper, 
 Oxychloride of bismuth, 
 Chloride of lead, 
 
 Arsenious acid, 
 Litharge, 
 Red lead, 
 Oxide of copper, 
 Metallic tin. 
 
TABLE D. 
 
 51 
 
 ft 
 
 5 | r | o w g 
 
 S o-C a 
 S ae .2 
 
 HH 
 
 O 3 03 
 
 * 2 * -12 
 
 
 
 a 
 ft 
 
 
 i 
 
 | 
 
 i ! 
 
 fc PH 
 
 I 
 
 _j " 
 
 s -3 ' -2 
 
 C 53 - S 
 
 S g 
 
 S g s 
 
 a S C 
 
 o d ' 
 
 c? ~ S - 
 
 Hi] 
 
 ills" 
 
 x ^ -5 - 
 
 r- O 
 
 o 
 
 fl 
 
 = g ? 
 
 .3 - 
 
 O oo 
 
 *N ., m '-^ 
 
 i i 1 * 
 
 u a> S 
 o." 1 a? H 
 
 p.x.o.2 
 M 2 
 
 s-'E J = 
 
 ^-i ii ~ *> 
 
 S Vi O 
 
 ..H.5'| S 
 I 111 
 
 o 
 o 
 
 resence o 
 of ainm 
 sulphide 
 , add oue 
 53;. 
 
 -11011111 
 
 
 B aT * -2 
 
 o B 
 i i < 
 
 O - ^i C - H 
 
 S - ^ - -5 
 c^ c3 ^ o bcPn 
 
 " M Hrf 5 '^- 
 
 ^T ^ O-"C H O ^ 
 
 < ' "x 2 
 
 hH ^ -S ~C O I ' 
 
 P. d 
 
 5 * 
 
 i i 
 
 * 
 
 : - o ; 7 
 
 -. 'v. 
 
 - 8*|f| 
 
 e~3 tufa 
 
 $-S ^~ 
 *- 3*** ft ^ 
 
 c JSs? 
 
 5 ^ ^ 
 -I 5 *? 5 
 
 ^ ts . 
 
 31 
 
 P. I 
 
 1= -a 
 
52 IRON IDENTIFIED. 
 
 NOTES TO TABLE D. 
 
 42. When time permits, it is desirable to collect a little 
 of the precipitate upon a filter (4), and to wash it (16) be- 
 fore treating it with hydrochloric acid, which may be poured 
 over it upon the filter. 
 
 43. A white or gray residue of sulphur, derived from the 
 sulphide of ammonium, is often left undissolved, especially if 
 the precipitate be treated w'ith hydrochloric acid without 
 being washed. 
 
 44. To ascertain whether the iron is present as a ferrous 
 or as a ferric salt, test the original solution, which should be 
 acid (18), with ferrocyanide of potassium. 
 
 Ferric salts give, with ferrocyanide of potassium, a dark 
 blue precipitate of ferrocyanide of iron (Prussian blue); and 
 with ferridcyanide of potassium, a dark brown solution, but 
 no precipitate. 
 
 Ferrous salts give, with ferrocyanide of potassium, a lighter 
 blue precipitate of the double ferrocyanide of iron and potas- 
 sium; and with ferridcyanide of potassium, a dark blue pre- 
 cipitate of Turnbull's blue. 
 
 Potash, added in excess, produces a brown precipitate in 
 solutions of ferric salts, and a dingy green precipitate in 
 those of ferrous salts; this precipitate slowly becomes brown 
 when exposed to the air, from which it absorbs oxygen. 
 
 Since nitric acid converts ferrous into ferric salts, no con- 
 clusion as to the state of the iron can be drawn from these 
 tests when that acid has been employed in dissolving the 
 substance. 
 
 45. Metallic Iron, Fe, would generally be recognized by 
 its external appearance. It dissolves slowly in dilute hydro- 
 chloric acid, evolving a disagreeable smell of impure hydro- 
 gen, quite different from that of hydrosulphuric acid (see 
 Sulphide of Iron, p. 55). Ammonia added in excess (5) to 
 this solution, gives a dingy green precipitate which gradually 
 
VARIETIES OF IRON DISTINGUISHED. 53 
 
 Wrought Iron (malleable or bar iron) may be identified 
 by warming two or three grains of it with diluted nitric acid 
 (specific gravity 1.2*) when it will dissolve entirely, yield- 
 ing a solution which is nearly colorless after cooling, pro- 
 vided that the nitric acid be free from chlorine. 
 
 Steel, when tested in this way, gives a solution which re- 
 tains a brown-yellow color after cooling, due to the products 
 of the action of nitric acid upon the combination of iron with 
 carbon, which is present in steel. 
 
 White Cast Iron, heated with nitric acid of the above 
 strength, also dissolves, leaving little or no black residue of 
 uncombined carbon, but the solution has usually a darker 
 color than that furnished by steel, because white iron com- 
 monly contains a larger proportion of carbon in combination 
 with the metal. 
 
 Gray Cast Iron (ordinary pig iron) leaves a considerable 
 black residue of graphite (uncombined carbon) when heated 
 with nitric acid, and if this be filtered off or allowed to sub- 
 side, the liquid will usually have a pale brown-yellow color, 
 produced by a little combined carban. 
 
 Mottled Cast Iron furnishes a result intermediate between 
 those obtained with white and gray cast irons, the color of 
 the solution being paler than in the former case, and the 
 black residue less abundant than in the latter. 
 
 For the common compounds of Iron, see next page. 
 
 * Three measures of ordinary strong nitric acid mixed with four 
 measures of water. 
 
54 IRON COMPOUNDS. 
 
 COMMON COMPOUNDS OF IRON. 
 
 Names. Composition. 
 
 Iron > 
 
 Magnetic oxide of iron, or 1 Iron, oxygen. 
 
 Ferroso-ferric oxide ) 
 
 Sulphate of iron, or | f Oxide of iron, sulphuric acid, 
 
 Ferrous sulphate ) \ Water. 
 
 Bisulphide of iron, ) T 
 
 Iron pyrites ) Iroll > slll P hur - 
 
 Sp""onor' r } Oxide of iron, carbonic acid. 
 
 Perchloride or sesquichloride of iron Iron, chlorine. 
 
 Ferrocyanide of iron, or | Iron, cyanogen (carbon and 
 
 Prussian blue ) nitrogen). 
 
 Iodide of iron Iron, iodine. 
 
 of iron > silicic acid 
 
 Sesquioxide of Iron, Fe 2 O 3 , or ferric oxide, is met with in 
 several forms. 
 
 Red Hcematite Ore, or natural sesquioxide of iron, is a 
 hard compact mineral of a dark reddish-brown color, not 
 easily reduced to a powder, which is dark red. It is not 
 dissolved by water, but hydrochloric acid slowly dissolves it, 
 yielding a yellow solution, which gives a rust-colored pre- 
 cipitate with ammonia. 
 
 Specular Iron Ore, another natural variety of the sesqui- 
 oxide, is black, and has a brilliant lustre. Its relations to 
 solvents resemble those of haematite. 
 
 Brown Haematite Ore contains water in combination with 
 ferric oxide, and will therefore give off steam when heated in 
 a dry tube (17). It varies in color through different shades 
 of yellow, brown, and red. Hydrochloric acid dissolves it 
 more rapidly than it does the two preceding ores. 
 
IRON COMPOUNDS. OO 
 
 The artificial sesquioxide of iron, which is commonly 
 known as Colcothar, Crocus, or Jewellers' Rouge, has a 
 brighter red color than haematite, which it resembles in its 
 behavior with hydrochloric acid. 
 
 Rust has the same characters as brown haematite. 
 
 Magnetic or Black Oxide of Iron, Fe 3 O 4 , as found in 
 nature, is a hard mineral with considerable lustre. Hydro- 
 chloric acid slowly dissolves it, with the aid of heat, yielding 
 a greenish solution which gives a dingy green precipitate on 
 addition of ammonia. The black oxide of iron which com- 
 poses forge scales possesses similar characters, but is usually 
 devoid of lustre. 
 
 Sulphate of Iron (copperas, green vitriol, FeSO 4 .H 2 O.6Aq.), 
 forms transparent green crystals, often streaked with rusty 
 brown. It dissolves when shaken with cold water, but when 
 boiled with water, it generally deposits a brown basic per- 
 sulphate of iron formed by the decomposition of some ferric 
 sulphate contained in the salt. This deposit is easily dissolved 
 by hydrochloric acid, forming a yellow solution. 
 
 Dried Sulphate of Iron, FeS0 4 , is a brownish-white pow- 
 der which is not easily dissolved by cold water, and behaves 
 like the green sulphate when boiled. Hydrochloric acid 
 readily dissolves it. 
 
 Sulphide of Iron, FeS, is a black substance somewhat 
 resembling iron itself, insoluble in water, but dissolving in 
 hydrochloric acid, and evolving a powerful offensive odor of 
 hydrosulphuric acid. On adding ammonia to this solution 
 before the hydrosulphuric acid is boiled off, a black precipi- 
 tate of sulphide of iron is obtained. 
 
 Iron pyrites, FeS 2 , has the color and lustre of pale brass. 
 It often occurs in distinct cubical crystals, but more com- 
 monly in rounded lumps which are dark brown externally, 
 and have a radiated crystalline structure when broken. It is 
 not attacked by water or hydrochloric acid, but nitric acid 
 dissolves it on boiling, with separation of flakes of sulphur 
 and formn.Hon of siilnhnrip. Moid, whip.li mn.v hp Ht*ts*t*ts*f\ K^r 
 
56 IRON COMPOUNDS. 
 
 Spathic Iron Ore, FeCO 3 , or ferrous carbonate, varies very 
 much in appearance, but usually forms grayish-white masses 
 which seem to be made up of tabular crystals. It is unaffected 
 by water, but dissolves in hydrochloric acid, assisted by heat, 
 with effervescence caused by the escape of carbonic acid. 
 
 The red carbonate of iron of the druggist is chiefly sesqui- 
 oxide of iron. 
 
 Per chloride of Iron, or muriate of iron, or ferric chloride, 
 Fe 2 Cl 6 , is only met with in solution, which has a yellow or 
 red color, and gives a rust-colored precipitate with ammonia. 
 The chlorine may be detected in it by nitrate of silver (Table 
 H). The tincture of sesquichloride of iron is known by its 
 alcoholic smell. 
 
 Prussian Blue, Fe 5 C ]2 N la , is. insoluble in water and in the 
 diluted acids. It may be known by its becoming brown 
 when boiled with potash; if the solution of ferrocyanide of 
 potassium thus obtained be filtered from the deposited per- 
 oxide of iron, and mixed with excess of hydrochloric acid, it 
 will give a blue precipitate on adding perchloride of iron. 
 Concentrated hydrochloric acid dissolves Prussian blue, on 
 boiling, giving a yellow solution, from which the Prussian 
 blue is precipitated by much water. 
 
 Iodide of Iron or ferrous iodide, FeI 2 , is commonly sold 
 in solution, often mixed with syrup to preserve it. Solution 
 of iodide of iron has a very pale-green color, but, if partly 
 oxidized, it is rusty brown and opaque. It may be tested 
 for iodine according to Table H. The solid iodide forms 
 brownish-green lumps which are deliquescent and have a 
 crystalline fracture. 
 
 The Iron Slags, or silicates of iron, obtained in the pro- 
 cesses of refining and puddling cast iron, are black and pos- 
 sessed of considerable lustre. They are unaffected by water, 
 but if finely powdered and boiled with hydrochloric acid 
 (especially if the acid be concentrated), they partly dissolve, 
 emitting an odor of hydrosulphuric acid (caused by the pre- 
 
COr.ALT AND ITS COMPOUNDS. 57 
 
 46. It is desirable to confirm the indication of Cobalt 
 either by the blowpipe (268), or by collecting this precipitate 
 upon a filter (4), washing it (1G) and dissolving it off the 
 filter with a little dilute hydrochloric acid. The solution 
 thus obtained should have a light pink color, and if a little 
 of it be dropped upon filter-paper, the latter should become 
 blue or green when gently warmed. Ferridcyanide of potas- 
 sium added to the solution should give a purple-brown pre- 
 cipitate. 
 
 47. Neither metallic cobalt, Co, nor its compounds are 
 frequently met with. The metal bears considerable resem- 
 blance to iron. 
 
 Cobalt- glance, one of its chief ores, composed of cobalt, 
 arsenic, and sulphur, CoS 2 .CoAs 2 , is a black lustrous mineral, 
 soluble in boiling nitric acid, yielding a pink solution, and 
 depositing flakes of sulphur. 
 
 Commercial Oxide of Cobalt, CoO, is a bluish-gray, brown 
 or black powder, according to the mode of preparing it. 
 Hydrochloric acid dissolves it to a green or blue liquid which 
 becomes pink when diluted. 
 
 Smalt is glass which lias been colored with cobalt and 
 powdered. It is insoluble in water, hydrochloric and nitric 
 acids. 
 
 Nitrate of Cobalt, Co2NO 3 .6Aq., is a red salt, very 
 soluble in water, and easily attracting moisture from the air. 
 It becomes blue when gently heated to expel water of crys- 
 tallization, and if heated more strongly, evolves brown 
 nitrous fumes, leaving black oxide of cobalt. 
 
 48. The indication of nickel may be confirmed by adding 
 to the original solution an excess of ammonia (which gives a 
 blue color, especially on heating), and of a yellow sulphide 
 of ammonium, when the sulphide of nickel first precipitated 
 will, in great measure, be redissolved to a muddy brown 
 solution. 
 
 49. Neither metallic nickel, Ni (which resembles iron), 
 
58 NICKEL. 
 
 Commercial Oxide of Nickel, NiO, is a dull green or brown 
 powder, which dissolves in hydrochloric acid, yielding a green 
 solution. 
 
 Sulphate of Nickel, NiSO 4 .7H 2 O, forms bright-green crys- 
 tals, which are easily dissolved by water to a green solution. 
 
 50. The indication of aluminium may be confirmed by 
 observing the character of the precipitate caused by ammonia 
 in the original solution.. The hydrate of alumina which is 
 then precipitated is nearly transparent, so that it might easily 
 be overlooked, but that bubbles of air are usually entangled 
 in it. If the liquid be warmed, the alumina separates in 
 more distinct flakes. 
 
 The potash employed in testing often contains alumina, 
 which renders it the more necessary to confirm the result by 
 testing the original solution. 
 
 In examining substances insoluble in water and acids, 
 silica is likely to be met with here, as well as alumina. To 
 separate them, the original acid solution should be evaporated 
 to dryness (84), and the residue warmed with hydrochloric 
 acid. On pouring the solution into a test-tube, the silica 
 will be seen in flakes, and if these be filtered off, and the 
 solution mixed with excess of ammonia, the flocculent pre- 
 cipitate of alumina will be obtained. 
 
 51. Metallic Aluminium, Al, resembles tin in appearance, 
 but is much lighter. It is distinguished from all other white 
 metals except platinum, by its resistance to the action of 
 nitric acid, and from platinum by its easily dissolving in 
 hydrochloric acid. 
 
ALUM. - 59 
 
 COMMON COMPOUNDS OF ALUMINIUM. 
 
 Names. Composition. 
 
 Clay or silicate of alumina Alumina, silicic acid, water. 
 
 Sulphate of alumina, or > Alumi sulphuric aci d, water. 
 Concentrated alum ^ 
 
 . ^ ( Alumina, sulphuric acid, 
 
 I Potash (or ammonia), water. 
 
 Emery Aluminium, oxygen. 
 
 Acetate of alumina Alumina, acetic acid, water. 
 
 Aluminate of soda Alumina, soda. 
 
 Kryolite Aluminium, sodium, fluorine. 
 
 Clay, being nearly insoluble in hydrochloric and nitric 
 acids, will be considered hereafter, as will Emery and Kryo- 
 lite for the same reason. 
 
 Sulphate of Alumina, Al 2 3SO 4 .18Aq., is sold as a white 
 or grayish opaque mass, of crystalline structure, and sweetish 
 astringent taste. It dissolves easily in water, yielding a 
 solution which reddens blue litmas. The sulphuric acid 
 may be detected with chloride of barium (Table H). 
 
 Alum may be either sulphate of alumina and potash, 
 KA12SO 4 .12Aq., or sulphate of alumina and ammonia, 
 NH 4 A12SO 4 .12Aq., or a mixture of both salts, according to 
 the conditions of its manufacture. It forms bright colorless 
 crystals, which have a sweet astringent taste, and dissolve 
 easily in cold water, yielding a solution which reddens blue 
 litmus. When heated on a knife or a piece of glass alum 
 easily melts, evolves much steam, and leaves a white opaque 
 swollen mass which is quite infusible. If this mass be held 
 so as to touch the outside coating of the flame, the violet- 
 
 * Potash-alum is composed of sulphate of alumina and sulphate 
 of potash, whilst ammonia-alum contains sulphate of alumina and 
 sulphate of ammonia. 
 
GO ZINC AND ITS COMPOUNDS. 
 
 blue tint imparted to the latter will indicate the presence of 
 potash. Ammonia may be detected by its odor, on boiling 
 the alum with potash. 
 
 Acetate of Alumina or Red Mordant is sold in a state of 
 solution in water. It has an odor of acetic acid (vinegar), 
 reddens blue litmus, and if diluted with much water and 
 boiled, yields a translucent gelatinous precipitate of basic 
 acetate of alumina. The presence of acetic acid may be 
 proved by the production of a, red color on adding perchloride 
 of iron. 
 
 Aluminate of Soda, 3Na 2 O.Al 2 O 3 , is a grayish-white 
 opaque substance, strongly alkaline to the taste, dissolving 
 easily in water, yielding a solution which blues red litmus. 
 On adding a single drop of diluted hydrochloric acid, a floccu- 
 lent precipitate of alumina appears, but is redissolved by an 
 excess of the acid. Addition of ammonia to this solution 
 produces the gelatinous precipitate of alumina. 
 
 52. To confirm the presence of zinc, mix the original 
 solution with ammonia in excess, filter, if necessary, and add 
 ferrocyanide of potassium, which produces a white precipitate 
 of ferrocyanide of potassium and zinc, generally appearing 
 yellow through the excess of ferrocyanide of potassium. 
 
 Potash produces, in solutions of zinc, a white precipitate 
 which dissolves easily in excess of potash. 
 (Blowpipe test for Zinc, see 267.) 
 
 53. Metallic Zinc, Zn, is easily dissolved by hydrochloric 
 acid or nitric acid, the latter serving to distinguish it from 
 aluminium (51). 
 
ZINC COMPOUNDS. 61 
 
 COMMON COMPOUNDS OF ZINC. 
 
 Composition. 
 
 Sulphate of zinc, or ) ( Oxide of zinc, sulphuric acid, 
 White vitriol $ ( Water. 
 
 r I Zinc, oxygen. 
 
 Carbonate of zinc, or ) Q M f . carbonic acid . 
 
 Calamine ) 
 
 Sulphide of zinc, or > Zi sul hur> 
 Blende $ 
 
 Chloride of zinc Zinc, chlorine. 
 
 Sulphate of Zinc, ZnS0 4 .7Aq., is usually met with in 
 shining needle-like crystals which dissolve easily in water. 
 The solution reddens blue litmus paper, and has a nauseous 
 metallic taste. The sulphuric acid may be detected by 
 chloride of barium (Table H). 
 
 Zinc White, ZnO, is insoluble in water, but dissolves in 
 hydrochloric acid, usually effervescing slightly from the 
 escape of carbonic acid, which the oxide of zinc absorbs from 
 the air. When heated, oxide of zinc becomes yellow, but 
 resumes its white color on cooling. 
 
 Carbonate of Zinc, ZnCO 3 , occurs in nature as Calamine, 
 which has a light brown color due to the presence of iron. 
 It is insoluble in water, but dissolves with effervescence in 
 hydrochloric or nitric acid. When the nitric solution is 
 mixed with an excess of ammonia, any iron which is present 
 will be precipitated as brown hydrated peroxide, and if this 
 be separated by nitration, the solution will yield a white pre- 
 cipitate with sulphide of ammonium. 
 
 Sulphide of Zinc or Blende, ZnS, also called Black Jack, 
 is another ore of zinc, commonly met with in black shining 
 dodecahedral crystals, the color of which appears to be due 
 to their containing sulphide of iron. It is not affected by 
 water, and dissolves very slowly in boiling hydrochloric acid, 
 
62 ZINC COMPOUNDS. 
 
 evolving the odor of hydrosulphuric acid. Nitric acid dis- 
 solves it, generally causing the separation of flakes of sulphur; 
 the solution behaves as described above in the case of 
 calamine. 
 
 Chloride of Zinc, ZnCl 2 , is commonly sold in solution 
 [Burnett's disinfecting fluid}. The chlorine may be detected 
 by nitrate of silver (Table H). Solid chloride of zinc is white 
 and opaque ; it absorbs moisture rapidly from the air, becom- 
 ing wet (deliquesces). 
 
 54. To confirm the presence of manganese, boil the 
 original solution with a very little nitric acid* to convert any 
 ferrous salt into ferric salt, and add chloride of ammonium 
 and a slight excess of ammonia (5). Filter from any precipi- 
 tate caused by iron present as an impurity ; test one part of 
 the filtered liquid with potassium ferrocyanide, which should 
 give a white precipitate; to the other part add potassium 
 dichromate, and heat ; a dark brown precipitate indicates 
 manganese. (Blowpipe test for Manganese, see 268.) 
 
 54a. If the manganese be contained in the original sub- 
 stance in the form of manganate or permanganate of potash 
 it will not be detected by the Table, but will be recognized 
 by the dark green or purple-red color of the solution. (See 
 below). 
 
 55. Metallic Manganese, Mn, is very uncommon. It 
 resembles iron in appearance, but when heated with water it 
 causes effervescence, from escape of hydrogen, accompanied 
 by a very peculiar odor caused by compounds of hydrogen 
 with the carbon contained in the metal. 
 
 * The addition of nitric acid may be omitted if the original sub- 
 stance was dissolved in hydrochloric acid and evolved the smell of 
 chlorine. 
 
MANGANESE COMPOUNDS. 63 
 
 COMMON COMPOUNDS OF MANGANESE. 
 
 Names. Composition. 
 
 or } 
 
 Sulphate of manganese \ 
 
 Permanganate of potash { 
 
 ( Manganic acid 
 Manganate of potash < p , , oxygen 
 
 Binoxide of Manganese, MnO 2 , (or Manganese as it is often 
 called) is found in nature, as Pyrolusite, in 6fae& shining 
 masses often exhibiting prismatic crystals. The oxide is also 
 met with in dull dark brown fragments which give a dark 
 brown powder. It is not attacked by water, but hydrochloric 
 acid dissolves it slowly, evolving a strong smell of chlorine. 
 If the solution be filtered (4) and mixed with ammonia in 
 excess, it often gives a brown precipitate of peroxide of iron, 
 which- is a common impurity of the mineral, and after this 
 has been filtered off, the solution will give a buff or flesh- 
 colored precipitate with sulphide of ammonium. 
 
 Sulphate of Manganese, MnS0 4 .5H 2 O, is met with (as an 
 artificial product) in crystalline masses of a pinkish color, 
 easily dissolved by hot water, yielding a solution which is 
 very nearly colorless. The sulphuric acid may be detected 
 by chloride of barium (Table H). 
 
 Permanganate of Potash, K 2 Mn 2 O 8 , is commonly sold in 
 the state of solution (Candy's disinfectant), known by its 
 magnificent purple red color, which is unchanged by cold 
 diluted hydrochloric acid, but vanishes on adding an excess of 
 hydrosulphuric acid, sulphur being separated. If a solution 
 of permanganate of potash be mixed with potash and filtered 
 once or twice through paper, the latter becomes brown from 
 
64 PHOSPHATES. 
 
 the deposition of binoxide of manganese, and a green solution 
 of manganate of potash passes through. 
 
 The solid permanganate of potash forms hard prismatic 
 crystals which appear almost black, but are really dark red 
 with a green reflection, and are at once known by the intense 
 purple color which they impart even to cold water. 
 
 Manganate of Potash, K 2 MnO 4 , is met with as a fine green 
 solution which becomes red (permanganate) when diluted 
 with much water, depositing brown hydrated peroxide of 
 manganese. Dilute nitric acid produces a similar change. 
 
 56. Several other substances beside phosphate of lime 
 might also be precipitated here, but this being far more 
 common than any of the others, would be found in most 
 cases to compose the precipitate. Phosphate of Alumina 
 (112), Phosphate of Magnesia, Oxalate of Lime, and Fluoride 
 of Calcium are some other common substances which might 
 be met with here. (Phosphate of Baryta and Phosphate of 
 Strontia would also be precipitated, but they are very un- 
 common.) 
 
 In order to be quite sure that phosphate of lime is present, 
 the original solution should be mixed with some acetate of 
 ammonia (prepared by adding acetic acid to ammonia until 
 it reddens blue litmus paper) and divided into two parts. 
 
 One part is tested with oxalate of ammonia, which will 
 produce a white precipitate of oxalate of lime. 
 
 The other part is tested with a drop of perchloride of iron, 
 which will give a white precipitate of phosphate of iron. 
 
 The common form of phosphate of lime, Ca 3 2PO 4 , is Bone 
 Ash, which is usually sold as a white powder, insoluble in 
 water but dissolving easily in hydrochloric acid, with slight 
 effervescence, due to the escape of carbonic acid from the 
 carbonate of lime always present in bones, and often leaving 
 a slight dark residue of charcoal. 
 
 Superphosphate of Lime, CaH 4 2PO 4 , is commonly sold 
 as a gray damp powder, which dissolves to a great extent in 
 water yielding a strongly acid solution. 
 
FLUOR SPAR. 65 
 
 57. Phosphate of Magnesia would be known by its not 
 yielding any precipitate on the addition of oxalate of ammonia, 
 as above directed for the detection of lime ; but if an excess 
 of ammonia be afterwards added, and the solution briskly 
 stirred (6) a crystalline precipitate of ammonio-phosphate of 
 magnesia will be deposited. 
 
 Should there be no precipitate, add some phosphate of 
 soda, and again stir. If this produces a precipitate, it will 
 indicate that magnesia has been precipitated in the wrong 
 place, in consequence of too little chloride of ammonium 
 having been added in Table A. 
 
 The only common form of phosphate of magnesia is that 
 of ammonio-phosphate or triple phosphate found in calculi, 
 MgNH 4 PO 4 ; it is insoluble in water, but dissolves easily in 
 hydrochloric acid. 
 
 58. Oxalate of Lime, CaC 3 O 4 , would be precipitated on 
 mixing its original solution with acetate of ammonia, since 
 it is insoluble in the acetic acid thus set free. 
 
 Oxalate of lime may be easily identified by its not effer- 
 vescing when moistened with hydrochloric acid, unless it has 
 been previously heated on a piece of glass or porcelain, when 
 it becomes converted into carbonate of lime, which should be 
 allowed to cool and tested with hydrochloric acid. It may 
 also be tested for oxalic acid according to (114). 
 
 59. Fluoride of Calcium, CaF 2 , or Fluor Spar is met 
 with in greenish or purple cubical crystals. Its powder re- 
 sembles powdered glass in appearance and feel. It is not 
 affected by water, and is dissolved only to a slight extent by 
 diluted hydrochloric acid, the filtered solution yielding a 
 flocculent precipitate with ammonia. 
 
 When heated on a knife, or thrown upon a hot surface, 
 fluor spar generally crackles and flies off, at the same time 
 emitting a peculiar phosphorescent light, somewhat resem- 
 bling that of burning sulphur. It may be tested for fluorine 
 according to Table G. 
 
 . If fhrnminrn hf> nrrspnf. in flip form nf plirnmnfp rr 
 
66 CHROMIUM COMPOUNDS. 
 
 bichromate of potash, it will not be detected in the Table, 
 but may be recognized by the yellow or red color of the 
 solution, and by the yellow precipitates which it gives with 
 acetate of lead and with nitrate of baryta. 
 
 60. The green solution produced by excess of potash will 
 deposit a green precipitate of oxide of chromium when 
 boiled. To confirm the presence of chromium, fuse a very 
 little of the original substance with nitrate of potash, in a 
 small tube (17), when a bright yellow mass of chromate of 
 potash will be produced. This may be dissolved in water, 
 and tested with acetate of lead which gives a yellow pre- 
 cipitate. 
 
 61. Metallic chromium, Cr, is not likely to be met with 
 in ordinary analysis. 
 
 COMMON COMPOUNDS OF CHROMIUM. 
 
 Names. Composition. 
 
 Oxide of chromium Chromium, oxygen. 
 
 Chrome iron ore Chromium, iron, oxygen. 
 
 Chromate of potash and ) ( Chromic acid (chromium & oxygen) 
 ) 
 
 Bichromate of potash ) ( Potash. 
 
 Chromate of lead, or ) ( Chromic acid, 
 Chrome-yellow j ( Oxide of lead. 
 
 Chrome-alum 
 
 Oxide of Chromium, Cr 2 O 3 , is a green powder which is 
 insoluble in water, but generally dissolves, at least partly, in 
 hydrochloric acid, yielding a green solution. If it has been 
 heated to redness, it is insoluble in hydrochloric and in 
 nitric acids, but may be dissolved by boiling it with strong 
 nitric acid, and adding a little chlorate of potash, which oxi- 
 dizes the chromium into chromic acid, recognizable by the 
 yellow precipitate of chromate of lead which is obtained on 
 adding acetate of ammonia (56) and acetate of lead. 
 
 Chrome Iron Ore, FeCrO,, is a hard mineral, of a dark 
 
CHROMIUM COMPOUNDS. 67 
 
 brown or dark green color, which is almost insoluble in 
 acids, and may be treated in a similar manner to the pre- 
 ceding, in order to detect the chromium. 
 
 Chromate of Potash, K 2 CrO 4 , forms bright yellow. crystals 
 easily soluble in water, giving a yellow solution, which be- 
 comes orange red when mixed with hydrochloric acid, from 
 the production of bichromate of potash. Hydrosulphuric 
 acid added in large excess to the acidified solution converts 
 it into green chloride of chromium, rendering it opaque from 
 the separation of sulphur. 
 
 Bichromate of Potash, K 2 CrO 4 .CrO 3 , is sold in large ir- 
 regular crystals of a fine orange red color, easily soluble in 
 water. The solution of this salt also becomes green when 
 mixed with hydrochloric and excess .of hydrosulphuric acids. 
 
 Chromate of Lead has been described at page 29. 
 
 Chrome Alum, KCr2SO 4 .12Aq., forms a dark purple 
 crystals, which dissolve in water, yielding a purple solution, 
 becoming green when boiled. 
 
 62. Examples for Practice in Table D The following 
 
 substances may be analyzed (10): 
 
 Chrome alum 
 Sulphate of nickel 
 Iron pyrites 
 Sulphate of manganese 
 Sulphide of iron 
 
 Oxide of zinc 
 Binoxide of manganese 
 Common alnm 
 Sulphate of iron 
 
 Peroxide of iron 
 Sulphate of zinc 
 Bone-ash 
 Metallic zinc. 
 
68 
 
 TABLE E. 
 
 
 moniaGroup 
 
 
 
 *^ 
 
 6 
 
 
 
 o 
 
 <j 
 
 . 
 
 
 1 
 
 CH 
 
 | 
 
 
 
 
 
 is 
 
 
 JH 
 
 5 
 
 | 
 
 
 
 d 
 
 
 
 V. 
 
 fl 
 
 ^Q 
 
 
 S 
 
 
 
 tj 
 
 
 r^J 
 
 & 
 
 o 
 
 
 " 
 
 M 
 erf 
 
 s" 
 
 
 S 
 
 
 
 | 
 
 
 g 
 
 1 
 
 C 
 
 H 
 
 X 
 
 O 
 + 
 
 ~ 
 
 w 
 
 t^ 
 
 bD 
 
 ^ 
 
 5 
 
 
 
 G 
 
 " 
 
 H 
 
 OJ 
 
 "& 
 
 Cj 
 
 
 ^-^ 
 
 ^0 
 
 
 
 
 1 1 
 
 ? 
 
 c? 
 
 
 p^ 
 
 'S 
 
 r 1 
 
 
 CC 
 
 * 
 
 "S 
 
 
 EXERC1 
 
 s 
 
 cd 
 o 
 
 H 
 
 
 
 
 
 
 
 CO 
 CD 
 
 
 
 S =3 ^ 
 
 
 
 * *3 
 
 o3 
 
 
 ^ .si 
 
 To 
 
 / s 
 
 - | S co- 
 
 O 
 
 ^ 
 
 SI 
 
 . o fl 
 
 CO -^ 
 
 II 
 
 H O 
 
 $ w 
 
 o 
 
 I i . i - 
 
 i!tvj|i 
 
 S 5 o -< ( as ~H - 
 
 fiS'83gS 
 
 S 5 | w 
 
 ^ rs 
 
 X 
 S X 
 
 <i o 
 
 evaporated to dryness 
 
 the carbonate of amn 
 of ammonium has bei 
 ted for calcium in col. 
 
 EH 
 
 
 -*-> m 
 
 02 c3 ^ CD 
 
 
 
 g ^1 | 
 
 
 
 S ^ ^ T ^ 
 
 
 * 
 
 G ^ ^g o rt 
 
 ,_, 
 
 -2 to 
 
 o g 73 ^ 
 
 cS 
 
 S 5 _ CO 
 
 *j^ c^ ^ -^ 
 
 a 
 
 
 ri ^ ^ ^ 
 
 To 
 
 1 '^ 1 . 
 
 
 o 
 
 2 
 
 w - e <* ^ .g Ar 
 
 S .- "^^ S" 3 ^ i ^ 5 8 
 
 '-' 9 "1 *" ^ 
 $H X ^ JS g 
 
 * II 
 
 w ftV g ^ 2 '? ^ T . 
 ^| HI ||| HI 
 
 .S rt > O 
 
 tt^i "S ^V3 
 
 *i '^ - - 5 -3 
 
 c ^ a^ ^ ^ 
 o ^ T3 c M 
 
 3|jfj 
 
 |1 
 
 glJ^l^Jt 
 
 iiggS 
 
 "o i 
 
 3 
 
 *3 |o- 1 
 
 ill 11 
 
 o 
 
 S^ o 
 
 V-t '^ ^ B 
 
 EH 
 
 C ** ^ 
 
 "* ^7t 'o 
 
 
 ^ 
 
 ll & i! 
 
 
 
 O HH> fi *^ p-3 
 
 .2 
 
 
 II ill 
 
 _, o3 .!i M 'a, 
 
 "^ 
 
 fl 
 
 S s ^ tc 
 
 'o 
 
 o 
 
 ^ fe . 
 
 IK 
 
 2 M 
 
 H^J ^ r^^rt 
 
 |3) 
 
 T O 173 
 
 ^ 1 r-, rf ,*J 
 
 aa-"'S 1 
 
 lilfi 
 
 * 1 m -^ 
 ^ "* cT-- rt 
 
 g C X. ^ 
 
 9 'S *!* ** ^ 
 
 JS ?" W S 
 
 "^^^ g 
 f lg -| 
 
 <H 
 
 & o o /r 1 3J 
 
 02 <y o P-( <P 
 
 
 O 
 -^ 
 
 J p. 
 
 o^ "^ i JQ 
 
 r^ <U j-j "5 <& 
 
 2 
 
 5 s 
 
 +* S c ^ g 
 
 ft 
 
 - 
 
 L^H ^ H -fJ L. 
 
 c3 
 
 
 
 * IH-:IS 
 
 O 
 
 
 "G -*^ 
 
 
 
 ^ S 
 
BARIUM COMPOUNDS. 69 
 
 NOTES TO TABLE E. 
 
 64. To confirm the presence of barium, add hydrofluo- 
 silicic acid to a portion of the original solution, and stir well 
 with a glass rod (6), when a semi-transparent crystalline pre- 
 cipitate of silicon 1 uoride of barium will be deposited. 
 
 Or, dissolve the carbonate of ammonia precipitate in acetic 
 acid, and add chromate of potash, which produces a yellow 
 precipitate of chromate of baryta. 
 
 65. Metallic Barium, Ba, is very uncommon. It speedily 
 oxidizes when exposed to the air, becoming converted into 
 baryta. 
 
 COMMON COMPOUNDS OF BARIUM. 
 
 Names. Composition. 
 
 Sulphate of baryta, or ) - 
 
 Heavy spar ( Bar yta (oxide of barium), sulphuric acid. 
 
 Carbonate of baryta, or ) 
 
 Witherite } Baiyta ' carbomc * C1(L 
 Chloride of barium Barium, chlorine, water. 
 
 Nitrate of baryta Baryta, nitric acid. 
 
 Hydrate of baryta Baryta, water. 
 
 Baryta Barium, oxygen. 
 
 Chlorate of baryta Baryta, chloric acid. 
 
 Chromate of baryta Baryta, chromic acid. 
 
 Sulphate of Baryta, BaSO 4 , being insoluble in water and 
 acids, will be considered hereafter. 
 
 Carbonate of Baryta, BaCO 3 , is found as a grayish-white, 
 heavy earthy mineral, insoluble in water, but dissolving, with 
 effervescence, in hydrochloric acid. If a glass rod or a 
 platinum wire be dipped into the solution, and held in the 
 margin of a flame (70), it will tinge the flame green. The 
 artificial carbonate of baryta is & pure white earthy powder, 
 which usually gives a milky solution in hydrochloric acid, 
 from a slight impurity of sulphate of baryta, not easily 
 filtered off. 
 
70 BARIUM COMPOUNDS. 
 
 Chloride of Barium or muriate of barytes, BaCl 2 .2Aq., 
 forms transparent flat crystals, which dissolve easily in 
 water. The chlorine may be detected by nitrate of silver 
 (Table H). 
 
 Nitrate of Baryta, Ba2NO 3 , forms colorless crystals, 
 which are dissolved by water. When heated in a dry 
 tube (17), it evolves brown fumes of nitric peroxide, and 
 leaves an infusible residue of baryta. 
 
 Hydrate of Baryta, BaH 2 O 2 , is sold either in colorless 
 crystals or as a white powder. The crystals soon become 
 opaque when exposed to the air, losing water and absorbing 
 carbonic acid. Hydrate of baryta dissolves easily in water, 
 yielding a strongly alkaline solution, soon rendered milky by 
 the carbonic acid of the air, especially if shaken in a test- 
 tube which has been breathed into. 
 
 Baryta, BaO, is sold as a gray porous solid, which be- 
 comes very hot when moistened with water, and crumbles to 
 a white powder of hydrate of baryta. 
 
 Chlorate of Baryta, Ba2ClO 3 , forms colorless crystals 
 soluble in water. Hydrochloric acid colors the solution 
 yellow, on applying heat, by decomposing the chloric acid, 
 and evolves a chlorous smell. Hydrosulphuric acid added 
 to this solution yields a white deposit of sulphur. Strong 
 sulphuric acid reddens the chlorate, and causes explosion on 
 heating. 
 
 Chromate of Baryta, BaCr0 4 , is a bright yellow powder, 
 insoluble in water, but soluble in hydrochloric acid, giving a 
 yellow solution, which becomes green when heated with 
 alcohol or allowed to remain in contact with metallic zinc, 
 chloride of chromium being formed. 
 
 66. To confirm the presence of strontium, apply the 
 colored flame test (70) to the original substance. 
 
 67. Metallic Strontium, Sr, is a rarity; it is soon con- 
 verted into strontia by absorbing oxygen from the air. 
 
STRONTIUM COMPOUNDS. 71 
 
 COMMON COMPOUNDS OF STRONTIUM. 
 
 Names. Composition. 
 
 Strontia (oxide of strontium), 
 
 Nitrate of strontia ^ Nitric acid, 
 
 Water. 
 
 } 
 
 Strontia > snI P huric add ' 
 Strontia, carbonic acid. 
 
 Nitrate of Strontia, Sr2"NO 3 .5Aq., forms colorless crystals, 
 which are easily dissolved by water ; paper dipped into the 
 solution and held in the margin of a flame (70) will color it 
 with flashes of crimson.* 
 
 - When heated in a dry tube (17), nitrate of strontia evolves 
 water and brown fumes of nitric peroxide, leaving an infu- 
 sible residue of strontia. Nitrate of strontia which has 
 been crystallized by boiling down its solution contains no 
 water. 
 
 Sulphate of Strontia, SrS0 4 , being nearly insoluble in 
 water and acids, will not be considered here. 
 
 Carbonate of Strontia, SrCO 3 , is usually found as a green- 
 ish mineral, which is insoluble in water, but dissolves in 
 hydrochloric acid with effervescence. Paper dipped into the 
 solution colors flame crimson* (70). 
 
 68. Oxalate of Ammonia also forms precipitates in solu- 
 tions containing barium and strontium, so that it can never 
 be used as a test for calcium, unless the absence of those 
 metals has been previously ascertained. 
 
 69. Metallic Calcium, Ca, is not likely to be met with 
 
 * Some care is requisite to avoid mistaking the orange-red tint 
 which calcium imparts to flame, for the crimson of strontium. 
 
72 LIME COMPOUNDS. 
 
 in ordinary analysis ; it quickly absorbs oxygen from the 
 air, and is converted into lime. 
 
 COMMON COMPOUNDS OF CALCIUM. 
 
 Names. Composition. 
 
 "Mm* 
 
 Carbonate of lime, or ) T . , ., 
 
 , ,, Lime, carbonic acid. 
 
 Sulpha^ of lime, or j Lime> sulphurio 
 
 Chloride of calcium Calcium, chlorine. 
 
 Chloride of lime, or } Lime, hypochlorous acid, 
 
 Bleaching powder, or < Chloride of calcium, 
 
 Hypochlorite of lime y (_ Water. 
 
 Oxalate of lime Lime, oxalic acid. 
 
 Phosphate of lime Lime, phosphoric acid. 
 
 Superphosphate of lime Lime, phosphoric acid, water. 
 
 Fluoride of calcium Calcium, fluorine. 
 
 Quick Lime, CaO, is a grayish white earthy solid, which 
 becomes hot when moistened with water, and crumbles after 
 a time to a white powder of hydrate of lime. 
 
 Hydrate of Lime, CaH 2 O 2 , is a light white powder, which 
 is not visibly dissolved by water, but dissolves easily in 
 hydrochloric acid, usually effervescing slightly, from the 
 presence of a little carbonate of lime. When shaken with 
 cold water, and filtered, hydrate of lime gives a solution 
 which turns red litmus blue, and becomes milky when shaken 
 in a test-tube which has been breathed into, from the pre- 
 cipitation of carbonate of lime. 
 
 Lime-water may be recognized by the test just given. 
 
 Carbonate of Lime, CaCO 3 , occurs in nature in several 
 forms, all of which, however, are* insoluble in water, but 
 
CALCIUM COMPOUNDS. 73 
 
 dissolve easily in hydrochloric acid, with brisk effervescence 
 from escape of carbonic acid. 
 
 Limestone and Chalk, which are the most impure of the 
 natural varieties of carbonate of lime, generally yield a 
 slight flocculent precipitate of alumina when their hydro- 
 chloric solution is tested with ammonia, and a green tinge, 
 from the presence of iron, when sulphide of ammonium is 
 added to the ammoniacal liquid. Marble Iceland Spar, and 
 prepared chalk, which are purer forms of the carbonate, do 
 not behave in the same way. 
 
 Magnesium Limestone, or Dolomite, CaMg2CO 3 , which 
 contains the carbonates of lime and magnesia, may be iden- 
 tified by dissolving it in diluted hydrochloric acid, adding 
 chloride of ammonium, ammonia, and carbonate of ammonia, 
 to precipitate the lime, boiling, filtering, and testing the 
 solution for magnesia with phosphate of soda, after proving, 
 by the addition of oxalate of ammonia, that all the lime has 
 been separated. 
 
 Sulphate of Lime, CaSO 4 , does not visibly dissolve in 
 water, although if the solution be filtered, a small quantity 
 of the salt will be found in solution. The sulphuric acid 
 may be detected by chloride of barium (Table H). Hydro- 
 chloric acid dissolves it to a greater extent, but, unless after 
 prolonged boiling, it might easily be concluded that sulphate 
 of lime was not dissolved by water or acids, so that it is 
 often found among substances of that class (Table I). 
 
 The several varieties of sulphate of lime differ consider- 
 ably in appearance. 
 
 Gypsum, CaSO 4 .2H a O, is a grayish-white, opaque, 
 earthy, brittle mineral. 
 
 Fibrous gypsum is made up of parallel silky fibres, which 
 are white, gray, or pink. 
 
 Selenite is transparent, or nearly so, either colorless, or 
 brownish-gray in color, and easily split into plates with a 
 knife. 
 
 Plaster of Paris (calcined gypsum} is a fine white oowder 
 
74 COLORED FLAME TEST. 
 
 which sets into a solid mass after a few minutes, if mixed 
 with water to a thin paste. 
 
 Chloride of Calcium is sold in three forms. The crys- 
 tallized chloride, CaCl 2 .6Aq., forms colorless transparent 
 crystals which rapidly absorb water from the air, and are 
 extremely soluble in water. Another variety is the porous 
 chloride, forming a white or grayish-white porous mass, 
 CaCl 2 .2Aq., which becomes wet (deliquesces) very rapidly 
 when exposed to air, and dissolves easily in water. The 
 fused chloride, CaCl 2 , has similar properties, but is a gray 
 fibrous crystalline solid. 
 
 The chlorine may be detected by nitrate of silver. 
 (Table H.) 
 
 Chloride of Lime, or bleaching powder, 2CaHClO 2 .CaCl 2 . 
 2H 2 O, is a white earthy powder, which has a strong smell of 
 hypochloric acid, resembling that of chlorine. It is partly 
 dissolved by water, and entirely by hydrochloric acid, with 
 effervescence, evolving a powerful odor of chlorine. Litmus 
 paper is at once bleached by the solution. 
 
 Oxalate of Lime, CaC 3 O 4 , in a pure state, is a white 
 powder, insoluble in water, but soluble in hydrochloric acid. 
 The method of identifying it has been described at (58). 
 
 Phosphate and Superphospate of Lime have also been 
 described at (56). 
 
 Fluoride of Calcium will be found described at (59). 
 
 70. Colored Flame Test. Although this test will be 
 more fully described in the Exercises with the Blowpipe, it 
 is necessary to refer to it here, because it affords so valuable 
 a confirmation of the results obtained by liquid tests in 
 Table E. 
 
 The chlorides of the metals furnish the most distinct 
 colored flames, since they are more easily vaporized and 
 mingled with the gases of the flame, when the hydrogen 
 abstracts the chlorine, and the metallic vapor burns with its 
 characteristic tint. Hence the substance to be tested should 
 be dissolved, if possible, in hydrochloric acid. 
 
COLORED FLAME TEST. 
 
 75 
 
 The best flame for this test is that of a Bunsen's air- 
 burner (fig. 23) ; but if this be not at hand, a fair substi- 
 
 Fia. 24. 
 
 FIG. 23. 
 
 Bunsen's Burner. 
 
 tute may be made by placing a small glass funnel (a, fig. 24), 
 with a rather wide neck, over a gas-burner, as shown in 
 fig. 24, where (6) is one of the flattened burners often em- 
 ployed for blowpipe experiments. The funnel is placed over 
 the jet before the gas is lighted ; the gas is then turned on 
 to a moderate extent, when it mixes with the air passing up 
 through the funnel, and by gradually diminishing the supply 
 of gas, it may be made to burn with a nearly non-luminous 
 flame, in the margin of which the glass rod, or, better, 
 platinum wire (74), moistened with the liquid under exami- 
 nation, should be held. 
 
 Fia.2). 
 
76 
 
 COLORED FLAME TEST. 
 
 be supported, so that a passage for air may be left between 
 the glass and the jet. 
 
 FIG. 26. 
 
 A spirit-lamp (fig. 26) may be used when gas is not 
 attainable, though it does not give so good results as the 
 gas-flame. 
 
 II. Examples for Practice in Table E. The following 
 compounds may serve as exercises in this Table (10) : 
 
 Chloride of barium 
 Nitrate of strontia 
 Carbonate of baryta 
 
 Chloride of calcium 
 
 Carbonate of lime (chalk or marble) 
 
 Sulphate of lime (plaster of Paris). 
 
TABLE F. 
 
 77 
 
 
 
 rj 
 
 = 1 
 
 
 CD 
 
 .1 
 
 ^"2 
 
 
 O 
 
 r-t 
 
 ji , 
 
 *s s 
 
 
 - X?^ 
 
 1 S|| 
 
 . -rlifl- 
 
 fl 
 
 
 J * T5 
 
 s ^ f "i o U)'" ^-^ 
 
 "2-3 
 
 
 g ^ -2 | 
 
 1 jl-S g's! i 
 
 2^ 
 
 1 
 
 5 * 3 |3 
 
 1 1 1 * 5 ^inl "i 
 
 ^ 
 
 
 
 2 * bo 
 
 ^ ^oTS^'g^^ 
 
 "g'l 
 
 
 
 c3 ,j ^ 
 
 S ^ H ^ /* 
 
 J-i o 
 
 o 
 
 02 PH -^ 
 
 ^ ^ O 
 
 
 S 
 
 4 
 
 S ^ 
 
 ^^3 
 
 S 
 <! 
 
 
 
 
 fill 
 
 ^ 
 
 
 
 ,0 ^ ^ _* 
 
 3 
 
 <-. 5 
 
 
 ^ *- o 
 
 2 
 
 I* 
 
 
 C S "^ o 
 
 issium, Sodium, 
 TABLE F. 
 
 ratlier strong solution 
 ;ance, and stir it (73) i 
 TARTARIC ACID,* 
 or with 
 
 IILORIDE OP PLATINUM 
 a slip of glass (76). 
 pitate formed in lines. 
 Presence of 
 Potassium (77). 
 
 snough tartaric acid m 
 previously acidified w 
 ate before testing with 
 alkaline by potash bef 
 
 p 
 
 c3 as 
 
 M ^ 
 
 LJ ^ 
 
 o 
 
 C5 ^ 
 
 ^Q SH 
 
 /^ ^ ^ 
 
 PH 
 
 ^ tn 
 
 PH 
 
 s "i is ^ 
 
 CH 
 
 g 2 
 
 
 ^ g "' 
 
 O 
 
 04 
 
 ** 
 
 
 1*1 2 
 
 P 
 
 o 
 
 
 
 2 &S ^ 
 
 43 
 
 
 
 'rf T, ^ 
 
 
 
 "3 
 
 
 r^ S 'S 
 
 .^ 
 
 3 CD 
 
 
 O & +? 
 
 <D 
 
 'So "S 
 
 
 IH r- 0) "* 
 
 P 
 
 ^ 
 5 ? 
 
 O /- " N| 
 
 1 ill 
 
 
 
 * *r^ .^ 
 
 O J>" 
 
 '^> '^ r TT) 
 
 ^ 
 
 II 1 1 
 
 S 
 
 2 i 
 
 ^ ^ ^ '** 
 
 "Sb-ti S "S 
 E ^.Hfo 
 
 
 o S J 
 
 2 s 
 
 ^^ M 
 
 
 PH w 
 
 53 ^ 
 
 o> 2 
 
 
 i ^ 
 
 
 4-l *- S 4-l 
 
78 
 
 PLATINUM WIRE. 
 
 EXPLANATIONS AND INSTRUCTIONS ON 
 TABLE F. 
 
 73. The precipitation of potassium with tartaric acid or 
 bichloride of platinum, and of sodium with antimoniate of 
 potash, is more readily effected by stirring on a slip of glass 
 than in a test tube. 
 
 Take a clean, dry slip of window-glass ; dip a glass rod (6) 
 into the solution to be tested, and place the drop so withdrawn 
 upon the slip of glass. Wipe the rod clean, and dip it into the 
 test, placing the drop withdrawn by the side of the other ; 
 
 notice that both drops 
 are clear, and stir 
 them briskly together 
 with the end of the 
 glass rod, which 
 should be moved in 
 circles, but not hard 
 enough to scratch the 
 glass (fig. 27). The preci- 
 pitate will then be deposited 
 in lines (fig. 28) upon those 
 parts of the slip of glass 
 which have been rubbed by 
 the rod. 
 
 74. The platinum wire for this purpose should be very 
 thin, so that one inch may weigh ^ grain. A piece about 
 three inches long should be fixed into a glass handle, which 
 is conveniently made by softening the centre of a narrow 
 glass tube in the blowpipe-flame (fig. 15), drawing it out to 
 
 FIG. 29. 
 
 FIG. 27. 
 
 FIG. 28. 
 
 a narrow neck (fig. 19), and cutting it off at a ; the platinum 
 wire is then inserted (fig. 29), and the glass fused round it 
 
AMMONIA AND ITS COMPOUNDS. 79 
 
 Since all platinum wire which has been fingered tinges 
 flame yellow (sodium having been derived from the perspi- 
 ration of the skin), it must be cleansed before use by holding 
 it in the margin of the flame until a yellow tinge is no longer 
 visible. 
 
 NOTES TO TABLE F. 
 
 15. Ammonium, NH 4 , is not known to have any separate 
 existence, but it is often very convenient to represent the 
 nitrogen and hydrogen in the salts of ammonia, as existing 
 in the form of a compound metal, capable of taking the same 
 part in the composition of those salts as is taken by potas- 
 sium and sodium in their salts. 
 
 COMMON COMPOUNDS OF AMMONIA. 
 
 Names. Composition. 
 
 \ r A ( Nitrogen, 
 
 Solution of ammonia, or \ j Ammonia, < ^ droo- n 
 Liquor ammonite ) ( Water. \ J o 
 
 Carbonate of ammonia Ammonia, water, carbonic acid. 
 
 Sulphate of ammonia Ammonia, water, sulphuric acid. 
 
 Nitrate of ammonia Ammonia, water, nitric acid. 
 
 Sulphide of ammonium Ammonia, hydrosulphuric acid. 
 
 Chloride of ammonium, or j Ammonia hydrochloric acid. 
 
 feal-ammoiiiac ) 
 
 Oxalate of ammonia Ammonia, water, oxalic acid. 
 
 Solution of Ammonia, NH 3 , has the strong odor of harts- 
 horn, does not effervesce with dilute hydrochloric acid, and 
 leaves no residue when evaporated on a slip of glass. 
 
 Chloride of Ammonium, or muriate of ammonia, or hydro- 
 chlorate of ammonia, or sal-ammoniac, NH 4 C1, is sold either 
 in white crystals or in translucent fibrous masses, usually 
 stained brown in places. It is very easily dissolved by water. 
 It has no ammoniacal smell, and when heated on a knife or 
 a slip of glass, it evaporates in white fumes without melting. 
 The chlorine may be detected with nitrate of silver. (Table 
 
 TT \ 
 
80 AMMONIACAL SALTS. 
 
 Carbonate of ammonia, or sesquicarbonate of ammonia, 
 or Preston salts, 2(NH 4 ) 2 CO 3 .CO 2 , lias a powerful odor of 
 .ammonia. It is usually sold in white opaque lumps, which 
 are transparent when freshly prepared. Carbonate of am- 
 monia dissolves easily in water, yielding a solution which 
 blues red litmus paper, and effervesces violently with 
 hydrochloric acid, in consequence of the escape of carbonic 
 acid. 
 
 Sulphate of ammonia, (NH 4 ) 2 SO 4 , forms prismatic crys- 
 tals, which are colorless when pure, but in their impure state 
 have a brownish color. It dissolves easily in water, and 
 has no ammoniacal odor. The sulphuric acid may be de- 
 tected by chloride of barium. (Table H.) 
 
 Nitrate of Ammonia, NH 4 NO 3 , is sold either in colorless 
 crystals or in opaque fused masses. It does not smell of 
 ammonia, and becomes damp on exposure to air ; easily 
 soluble in water. When heated on a slip of glass, it melts 
 very easily, boils, and passes off entirely as nitrous oxide gas 
 and steam. The nitric acid may be detected as in Table H. 
 
 Sulphide of Ammonium, or hydrosulphate of ammonia, 
 (NH 4 ) 2 S, is common in a state of solution only. 
 
 The solution is yellow (though colorless when quite freshly 
 prepared), and has a very offensive ammoniacal smell, and 
 an alkaline reaction. The addition of hydrochloric acid 
 causes a milkiness, due to the precipitation of sulphur, and 
 an escape of hydrosulphuric acid, recognized by its odor. 
 
 Oxalate of Ammonia, (NH 4 ) 2 C 2 O 4 .Aq., forms shining, 
 white, needle-like crystals, which are free from ammoniacal 
 smell, and dissolve easily in water. The oxalic acid may be 
 detected according to Table H. 
 
 76. The precipitate produced by tartaric acid is the bi- 
 tartrate of potash, KIIC 4 H 4 O 6 . The (yellow) precipitate 
 produced by platinum chloride is the platinochloride of potas- 
 sium, 2KCl.PtCl 4 . Since ammonium is precipitated by the 
 same tests, it is absolutely necessary to prove its absence 
 
POTASH SALTS. 81 
 
 Should platinum chloride produce a dark red color, iodine 
 is probably present. (See Iodide of Potassium (77).) 
 
 77. Metallic Potassium, K, is not met with in ordinary 
 analysis. It is oxidized immediately by exposure to air, 
 and takes fire in contact with water, burning with a violet 
 flame. 
 
 COMMON COMPOUNDS OF POTA.SSIUM. 
 Names. Composition. 
 
 Nitrate of potash, or ) ( Potash j P tassium > 
 
 Nitric ad?"' 
 
 Potash > carbonio 
 
 Bicarbonate of potash Potash, carbonic acid, water. 
 
 Sulphate of potash Potash, sulphuric acid. 
 
 Bisulphate of potash Potash, sulphuric acid, water. 
 
 Chloride of potassium Potassium, chlorine. 
 
 Hydrate of potash Potash, water. 
 
 Bitartrate of potash Potash, tartaric acid, water. 
 
 Chlorate of potash Potash, chloric acid. 
 
 Fen-ocyanideof potassium, or 
 
 Prussiate of potash iron, water. 
 
 ) j 
 * ( 
 
 Potassi, lm , cyanogen, iron. 
 
 Cyanide of pot^um * 1 - ^^ { 
 
 Iodide of potassium Potassium, iodine. 
 
 Acid oxalate of potash Potash, oxalic acid, water. 
 
 Silicate of potash Potash, silicic acid. 
 
 Soft soap Potash, oleic acid, water. 
 
 Nitre, or nitrate of potash, KNO 3 , is easily soluble in 
 water, and readily deposits in prismatic crystals from a hot 
 and strong solution allowed to cool. 
 
 Placed on the point of a knife and held in the margin of a 
 flame (70), it melts, boils, and colors the flame blue violet. 
 
82 SALTPETRE. CHLORATE OF POTASH. 
 
 Heated in a dry tube (17), it easily melts to a clear liquid, 
 in. which a piece of wood or paper burns with vivid defla- 
 gration. Brown nitrous fumes may afterwards be seen and 
 smelt in the upper part of the tube. 
 
 The nitric acid may be detected according to Table H. 
 
 Nitre is met with in commerce in several forms. 
 
 The grough, or impure nitre, as imported from India, con- 
 sists of small brownish irregular crystals, owing its color to 
 the presence of vegetable matter from the earth out of which 
 it is extracted. 
 
 The common saltpetre of the shops forms colorless irregu- 
 lar crystalline lumps. 
 
 Refined saltpetre forms colorless prismatic crystals, often 
 marked with longitudinal grooves, or else a pure white crys- 
 talline powder (saltpetre flour). 
 
 Sal Prynelle is saltpetre which has been melted and cast 
 into the form of opaque white bullets. 
 
 Chlorate of Potash, KC1O 3 , forms colorless flat crystals. 
 It is not easily soluble in cold water. Hot water dissolves 
 it, but readily deposits it in flat crystals on cooling. The 
 solution of chlorate of .potash becomes yellowish and emits a 
 chlorous odor when heated with hydrochloric acid, the 
 chloric acid being decomposed, and when hydrosulphuric 
 acid is added to the acidified solution, a white milky precipi- 
 tate of sulphur is obtained. 
 
 Heated in a dry tube (17), it easily melts to a clear liquid, 
 which soon boils and evolves oxygen, recognized by its 
 kindling into a blaze a spark at the end of a match held at 
 the mouth of the tube. 
 
 Carbonate of Potash, K 2 C0 3 , soon becomes damp (deli- 
 quesces) when exposed to air, from absorption of water. It 
 dissolves easily in cold water, yielding a very alkaline solu- 
 tion which effervesces briskly on adding hydrochloric acid. 
 
 The carbonate of potash which is known as American pot- 
 ash, or pearlash, forms bluish-white half-fused lumps. Salt 
 of tartar is a white crvstalline nowder. 
 
POTASSIUM COMPOUNDS. 83 
 
 Bicarbonate of Potash, KHCO,, is sold either in transparent 
 prismatic crystals, or as a white powder. It does not deli- 
 quesce in air, dissolves less easily in cold water than the car- 
 bonate, and the solution is not so strongly alkaline. 
 
 When the solution of bicarbonate of potash is heated to 
 boiling it effervesces slowly, from the escape of carbonic 
 acid. If solution of sulphate of magnesia be added to a 
 solution of bicarbonate of potash (prepared with cold water) 
 it does not produce a precipitate until the solution is boiled, 
 whilst the carbonate of potash produces a precipitate without 
 boiling. 
 
 Sulphate of Potash, K 2 8O 4 , forms hard, colorless, prisma- 
 tic crystals, which do not dissolve very quickly in cold water. 
 Its solution does not redden blue litmus paper. 
 
 Bisulphate of Potash, KHSO 4 , dissolves more easily in 
 \vater, yielding a strongly acid solution, reddening blue 
 litmus paper. 
 
 Chloride of Potassium, KC1, forms white cubical crystals, 
 which crackle (decrepitate) when heated on a slip of glass, 
 and dissolve very easily in cold water. The chlorine may be 
 detected by nitrate of silver (Table H). 
 
 Hydrate of Potash, KHO (caustic potash, or potassafusa), 
 is sold either in lumps or round sticks somewhat resembling 
 porcelain, and generally cream-colored (older samples have 
 a blue color). It becomes wet almost immediately when ex- 
 posed to air, and dissolves very quickly in cold water, pro- 
 ducing much heat, and a strongly alkaline solution. 
 
 The liquor potassce, or solution of potash, generally con- 
 tains a little carbonate of potash, but it may be distinguished 
 from a solution of that salt by its not effervescing with the 
 first drop or two of hydrochloric acid, the carbonic acid not 
 escaping until the whole of the hydrate of potash has been 
 neutralized. Mercuric chloride gives a bright yellow pre- 
 cipitate with the solution of potash. Nitrate of silver gives 
 a dark brown precipitate. 
 
 Bitartrate of Potash, or Cream of Tartar, KHC 4 H 4 O 6 , is 
 
84 FRUSSIATES OF POTASH. 
 
 soluble with some difficulty in cold water, but dissolves in 
 boiling water, and is deposited in shining crystals on cooling. 
 The solution reddens blue litmus paper. Hydrochloric acid 
 easily dissolves it. When heated on a slip of glass, or the 
 blade of a knife, bitartrate of potash blackens, from the 
 separation of charcoal, and emits a peculiar odor of burnt 
 sugar, due to the decomposition of the tartaric acid. The 
 residue, when moistened with water, turns red litmus blue, 
 and effervesces strongly with hydrochloric acid, the bitar- 
 trate of potash having been converted into carbonate. 
 
 Cream of tartar is a white crystalline powder. 
 
 The impure Bitartrate of Potash known as Argol, is sold 
 in irregular crystalline lumps of a brown or dark purple 
 color, derived from the grape-juice which deposits it. Such 
 Argol often contains much tartrate of lime. Refined Argol 
 forms white crystalline lumps. 
 
 Chr ornate and Bichromate of Potash were described at (61). 
 
 Ferrocyanide of Potassium, K 4 C 6 N 6 Fe.3Aq., is sold in 
 yellow crystalline masses. It dissolves easily in water to a 
 yellow solution, which becomes blue when mixed with hydro- 
 chloric acid and warmed, at the same time evolving the 
 peculiar odor of prussic acid. Perchloride of iron gives a 
 dark-blue precipitate of Prussian blue with the solution of 
 ferrocyanide of potassium. 
 
 Ferridcyanide, or Ferricyanide of Potassium, K 3 C 6 N 6 Fe, 
 forms dark-red prismatic crystals, which dissolve easily in 
 water, giving a green solution. The solution gives an 
 intensely blue precipitate with sulphate of iron. 
 
 Cyanide of Potassium, KCN, is sold in white porcelain-like 
 masses or sticks, which smell of prussic acid, and slightly of 
 ammonia, resulting from decomposition. The cyanide soon 
 becomes damp in air, and dissolves very easily in cold water. 
 The solution is strongly alkaline. Commercial cyanide of 
 potassium always contains carbonate and cyanate of potash, 
 so that it effervesces strongly on addition of hydrochloric acid, 
 evolving a powerful odor of prussic acid. 
 
POTASH SALTS. 85 
 
 The cyanogen may be detected according to (98). 
 
 Iodide of Potassium, or hydriodate of potash, KI, forms 
 white cubical crystals, often brownish after exposure to the 
 air of the laboratory, from separation of a little iodine. It 
 dissolves very easily in cold water. If the solution be boiled 
 with a little nitric acid, it evolves violet vapors of iodine. 
 
 Acid Oxalate of Potash, or salt of sorrel, or essential salt 
 of lemons, may be either the binoxalate, KHC 2 O 4 .Aq., or 
 quadroxalate of potash, KH 3 2C 2 O 4 .2Aq. It forms hard 
 white crystals, not easily dissolved by cold water, but soluble 
 in hot water, yielding a solution which strongly reddens blue 
 litmus. When heated on a knife-blade or a slip of glass, the 
 oxalate (is not blackened, like the bitartrate, but) is con- 
 verted into carbonate of potash, which may be recognized by 
 its strongly bluing moistened red litmus, and effervescing 
 when moistened with hydrochloric acid. 
 
 Silicate of Potash, K 4 SiO 4 , or Soluble Glass, is sold either 
 as a gummy liquid or in fused masses, which dissolve slowly 
 in water. The solution of silicate of potash is strongly alka- 
 line; when diluted hydrochloric acid'is gradually added to it, 
 slight effervescence generally takes place, from the presence 
 of a little carbonate of potash, and when the solution is 
 nearly neutralized, the silicic acid begins to separate in the 
 gelatinous form, especially on heating, sometimes converting 
 the whole solution into a jelly. The presence of silicic acid 
 may be established beyond doubt according to (118). 
 
 Soft Soap, or Oleate of Potash, KC 18 H 33 O 2 , is known by 
 its peculiar appearance and smell. It dissolves in water, 
 yielding an alkaline solution, which becomes milky with 
 diluted hydrochloric acid, from the separation of oleic acid. 
 On boiling the acidified solution, the oleic acid collects on 
 the surface as an oily layer. 
 
 1Q. Since a very minute quantity of sodium will impart 
 a distinct yellow color to flame, it often happens that a little 
 of this substance present as an impurity is regarded by the 
 
 ITIOV otMon orl If *} -i f* 1 4-" 4- 4- * 4-V V* 
 
86 DETECTION OP SODIUM. 
 
 stance under examination. To avoid error, some collateral 
 evidence must be sought for. Thus, it should be ascer- 
 tained whether the substance under examination possesses 
 the characters of any of the compounds of sodium described 
 (in 80). 
 
 If the original solution be neutral or alkaline to test-paper, 
 and no metal has been found by the application of any pre- 
 vious tests, then it may be 'inferred, if the substance imparts 
 a distinct bright yellow color to the flame, that sodium is an 
 essential constituent of it. 
 
 'TB. Although antimoniate of potash is a very excellent 
 test for sodium, when the solution is freshly prepared, it does 
 not answer so well in dilute solutions containing sodium, if 
 the antimoniate has been kept for some time in solution. 
 Another objection to the test is the circumstance that very 
 small quantities of lime, and some other bases, will give bulky 
 precipitates with the antimoniate of potash, altogether mis- 
 leading the analyst. Free acids also cause a milky precipi- 
 tate of antimonic acid. 
 
 80. Metallic Sodium, Na, is a soft metal, with a silvery 
 lustre when freshly cut, but tarnishing with extreme rapidity 
 when exposed to air. Thrown upo.n water, it fuses, and the 
 silvery globule floats over the surface, emitting a hissing 
 sound, from the escape of hydrogen ; on applying a light, the 
 hydrogen burns with a bright yellow flame. 
 
 For the common compounds of sodium, see next page. 
 
CARBONATE OF SODA. 
 
 87 
 
 COMMON COMPOUNDS OF SODIUM. 
 
 Names. 
 
 Carbonate of soda 
 
 Bicarbonate of soda 
 Hydrate of soda, or 
 Caustic soda 
 
 Soda-ash 
 
 Common salt 
 Sulphate of soda 
 Nitrate of soda 
 Sulphite of soda 
 Hyposulphite of soda 
 
 Chloride of soda 
 
 Phosphate of soda 
 Arseniate of soda 
 Biborate of soda, or ' 
 Borax 
 
 Silicate of soda 
 Tungstate of soda 
 Soda-soap, or } 
 
 Hard soap 
 
 Composition. 
 
 ( Soda (oxide of sodium). 
 ( Carbonic acid. 
 Soda, carbonic acid, water. 
 
 Soda, water. 
 
 f Hydrate of soda. 
 ( Carbonate of soda. 
 
 Sodium, chlorine. 
 
 Soda, sulphuric acid. 
 
 Soda, nitric acid. 
 
 Soda, sulphurous acid, water. 
 
 Soda, hyposulphurous acid, water. 
 / Hypochlorite of soda. 
 ( Chloride of sodium, water. 
 
 Soda, phosphoric acid, water. 
 
 Soda, arsenic acid, water. 
 
 Soda, boracic acid, water. 
 
 Soda, silicic acid. 
 
 Soda, tungstic acid. 
 ( Soda, stearic, oleic, or palmitic 
 ( acid, water. 
 
 Carbonate of soda, Na 2 CO 3 , dissolves easily in water, 
 yielding a strongly alkaline solution, which effervesces 
 strongly, from escape of carbonic acid, when hydrochloric 
 acid is added. 
 
 Common washing-soda, Na 2 CO.j.lOAq., is crystallized 
 carbonate of soda, containing nearly two-thirds of its weight 
 of water. The crystals effloresce, or become opaque at the 
 surface when exposed to the air, from loss of water. When 
 heated on a knife or a slip of glass, crystallized carbonate of 
 soda melts, boils, evolves much steam, and leaves a white 
 dry residue, which requires a blowpipe-heat to fuse it. 
 
 The carbonate of soda in powder, which is sold by the 
 druggist is a bicarbonate of soda, NaHC0 3 , which is less 
 easily dissolved by water than the true carbonate ; the solu- 
 tion is not so strongly alkaline, and effervesces when boiled, 
 
88 SODA ASH. PERUVIAN SALTPETRE. 
 
 from escape of carbonic acid. It may also be distinguished 
 from the true carbonate by testing it with sulphate of mag- 
 nesia. See Bicarbonate of Potash. 
 
 Hydrate of Soda, NaHO, or Caustic Soda is commonly 
 sold in opaque white fused masses which rapidly absorb mois- 
 ture from the air. It dissolves very easily in water, evolving 
 heat, and yielding a very strongly alkaline solution which 
 effervesces very slightly, if at all, with hydrochloric acid. 
 
 Soda-Ash is a mixture of carbonate of soda and hydrate of 
 soda, which has the appearance of earthy lumps or coarse 
 powder. It dissolves in water, generally leaving a slight 
 flaky residue of impurities, including some particles of car- 
 bonaceous matter. Its solution does not effervesce on the 
 addition of the first two or three drops of hydrochloric acid, 
 these being neutralized by the hydrate of soda, but a further 
 addition of the acid decomposes the carbonate of soda, with 
 effervescence. The solution generally contains traces of 
 alumina and lime. 
 
 Common Salt or Chloride of Sodium, NaCl, is of course 
 easily recognized by its taste. It is readily soluble in cold 
 water. The chlorine may be detected by nitrate of silver 
 (Table H). 
 
 Sulphate of Soda or Glauber's Salt, Na 2 SO 4 .10Aq., is 
 usually sold in transparent prismatic crystals, which soon be- 
 come opaque (effloresce) when exposed to the air, from loss 
 of water of crystallization. It dissolves easily in water. 
 The sulphuric acid may be detected with chloride of barium 
 (Table H). 
 
 Salt-cake is fused sulphate of soda, Na 2 3O 4 , and forms 
 opaque white masses which are much less pure than the 
 crystalline sulphate, so that they do not give a clear solution 
 in water, and the solution is acid, from the presence of some 
 bisulphate of soda. 
 
 Nitrate of Soda, NaNO 3 , or Peruvian or Chili saltpetre 
 or cubic nitre, forms colorless crystals ; the crude salt, how- 
 
SODIUM COMPOUNDS. 89 
 
 ever, is often brown or gray. It becomes moist when ex- 
 posed to air, and dissolves very easily in water. Placed on 
 the point of a knife, and held in the margin of a flame, it 
 colors it intensely yellow. When heated in a dry tube, it 
 behaves like nitrate of potash (77). The nitric acid may be 
 detected according to Table H. 
 
 Sulphite of Soda, Na 2 SO 3 .7Aq., when freshly prepared, 
 forms transparent crystals, but they soon become opaque at 
 the surface when exposed to air. It dissolves easily in water, 
 yielding a solution which turns red litmus paper blue, and- 
 lias a decidedly sulphurous taste. On adding diluted hydro- 
 chloric acid, the solution evolves the odor of sulphurous acid, 
 and hydrosulphuric acid renders the acidified solution milky 
 by causing the separation of sulphur. 
 
 Hyposulphite of Soda, Na 2 S 2 O 3 .5Aq., forms brilliant 
 transparent crystals which dissolve very easily in water. On 
 adding diluted hydrochloric acid to the solution, it slowly 
 becomes milky and acquires a yellow color, from the sepa- 
 ration of sulphur, the odor of sulphurous acid being per- 
 ceptible at the mouth of the tube. . 
 
 Hypochlorite of Soda, NaCIO, is always sold in solution 
 under the names of Chloride of Soda and Liquor Sodce 
 Chlorinatce. It has a strong smell of hypochlorous acid 
 (somewhat resembling that of chlorine). On adding diluted 
 hydrochloric acid, it becomes yellowish and evolves a power- 
 ful odor of chlorine;. Test-papers are at once bleached by 
 the acidified liquid. 
 
 Phosphate of Soda (common phosphate, orthophosphate, 
 .or rhombic phosphate of soda, Na 2 HPO 4 .12Aq.) forms trans- 
 parent crystals, which effloresce, or become opaque from loss 
 of water, when exposed to the air. It dissolves easily in 
 water, and the solution turns red litmus paper blue. The 
 phosphoric acid may be detected according to Table H. 
 
 Arseniate of Soda has been described at (35). 
 
 Biborate of Soda or Borax, Na 2 O.2B 2 O 3 .10Aq., is com,- 
 monly sold either as a white powder, or in transparent 
 
90 SODA SALTS. 
 
 crystals which lose water and become opaque when exposed 
 to air. It dissolves easily in water, and the solution turns 
 red litmus paper blue. When heated on a knife or a slip of 
 glass, it melts and swells up, evolving steam, and leaving a 
 white porous mass. When fused in the blowpipe-flame in a 
 loop of platinum wire (243) it forms a bead of glass which 
 remains transparent on cooling. The boracic acid may be 
 detected according to Table H. 
 
 Glass of Borax or vitrified borax, Na a O.2B 2 O 8 , forms 
 transparent or semi-transparent glassy-masses, which are 
 dissolved slowly even by boiling water, and require the blow- 
 pipe-flame to effect their fusion. 
 
 Silicate of Soda, Na 4 SiO 4 , or Soluble Glass is generally 
 sold as a grayish gummy solution, which behaves in the 
 same manner as the solution of silicate of potash (p. 85). 
 
 Tungstate of Soda, Na, 2 WO 4 .2Aq., is commonly sold in 
 opaque, irregular crystals, which dissolve easily in water, 
 yielding an alkaline solution, which gives a white precipitate 
 of tungstic acid on adding diluted hydrochloric acid; if a 
 piece of zinc be placed in the solution to which an excess of 
 hydrochloric acid has been added, a beautiful blue oxide of 
 tungsten is gradually formed. 
 
 Soda-soap is soluble in warm water, giving a solution 
 which turns red litmus paper blue, and gives a white pre- 
 cipitate of stearic acid on addition of hydrochloric acid. 
 When this precipitate is boiled in the liquid, it collects as an 
 oily layer upon the surface. 
 
 81. Examples for Practice in Table F. The following 
 substances may be analyzed for practice (10): 
 
 Chloride of ammonium 
 Bicarbonate of potash 
 Chloride of sodium 
 Biborate of soda 
 
 Carbonate of soda 
 Carbonate of potash 
 Sulphate of soda 
 Nitrate of potash. 
 
TABLE G. 
 
 91 
 
 rt 
 . m 
 
 
 +* 
 
 
 H 
 
 
 d 
 
 
 M 
 
 
 p 
 
 
 H 
 
 
 i 
 
 
 O 
 
 
 1 
 
 ^ 
 
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 J 
 
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 111 
 
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 11 
 
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 53 
 
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 ACID. 
 , Effervescence indi 
 Carbonic Acid ; i 
 Hydrosulphui ic 
 97). 
 
 1 
 
 
 
 1 
 
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 ^ 
 
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 * 
 
 83 
 
 s^ 
 
 ^t 
 
 58 
 
 Sao 
 
 S--2L 
 
 Odor of buruinu: su 
 
 Sulphurous Acid 
 
 Hyposu Ip hurous 
 (deposition of snl 
 
 , No satisfactory res 
 
 B. If no effect has 
 huric (Table H., co 
 le H., col. 6), and /S 
 
 ic acid will be prod 
 
 
 
 w 
 
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 rCJ 
 
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 5 
 
 
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 M 
 
 
 
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92 
 
 TABLE II. 
 
 being 
 
 ng one Acid or Non 
 
 c) (85). 
 
 83. Examination of Solutions contain 
 
 Organ 
 
 
 
 ,2 - 
 
 
 
 
 
TABLE H. 
 
 93 
 
 
 
 
 
 
 (C 
 
 
 
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 M 
 
 Pi 
 CO 
 
 
 
 u 
 
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 ^ 
 
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 ^ 
 
 
 
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 Add 
 
 LPHATE 
 
 [ANGANE! 
 
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 chlorous 
 
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 C. TlYDROCHLO 
 
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 Chloric Acid 
 
 (90), 
 
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94 
 
 EVAPORATION. GAS BURNERS. 
 
 NOTES TO TABLES G AND H. 
 
 84. To evaporate a solution Pour the solution into an 
 evaporating dish (a, fig. 30), supported on the ring of a 
 retort-stand (6), and applying a moderate heat. 
 
 FIG. 30. 
 
 FIG. 31. 
 
 Evaporation. 
 
 If the residue spurts about as the evaporation draws to a 
 close, place the dish upon an empty metal pot (fig. 31) to 
 equalize the heat over its under surface, and let it remain 
 there till thoroughly dry. 
 
 Gas-lamps are by far the most convenient for evaporating 
 solutions. 
 
 The Argand Burner (fig. 32) is one of the best for general 
 
 Fia. 32. 
 
GAS BURNERS. 
 
 use. It should be made so that by unscrewing the burner, 
 a plain jet (fig. 33) for blowpipe experiments may be ob- 
 
 FIG. 33. 
 
 tained. A brass chimney (c, fig. 32) may be made to drop 
 loosely over the burner, resting upon its shoulder (a), so as 
 to increase the temperature for some operations. It is also 
 convenient to have a brass ring (6), holding a piece of iron 
 wire gauze (with about 400 meshes to the square inch) which 
 may be dropped over the chimney (fig. 34), and the gas 
 lighted above it, so as to obtain the very hot smokeless flame 
 of .the mixture of gas and air. It is not advisable, however, 
 to use this flame for small evaporations, since it overheats 
 the sides of the dish and cracks it. 
 
 FIG. 34. 
 
 FIG. 3-5. 
 
 Gauze burner. 
 
 Bunsen's burner. 
 
 The Bunsen's burner (fig. 35) furnishes a very hot smoke- 
 less flame, produced by the admixture of air with the 
 gas. A burner on the same principle may be extemporized 
 with a glass funnel and a plain gas-burner, as described at 
 (70). 
 
 By twisting a band of folded paper round the lower part 
 
96 FLUORINE DETECTED. 
 
 of the Bunsen's burner, so as to close the air-holes, a lumi- 
 nous flame fit for blowpipe work may be obtained. Such 
 an arrangement also allows the burner to be used with a 
 smaller supply of gas. 
 
 FlQ 36 Where gas is not to be ob- 
 
 tained,* a spirit lamp (fig. 36) 
 may be used for evaporation, or 
 even a common candle-flame, if 
 the dish be supported at some 
 little distance above the flame 
 so that it may not be smoked. 
 
 85. An organic substance is 
 a substance of animal or vege- 
 table origin ; such substances 
 commonly carbonize when heated (17). 
 
 86. Since the action of sulphuric acid upon some sub- 
 stances is very violent, care is requisite in this experiment; 
 the test-tube should not be held near the face, and a small 
 quantity of the substance should be employed. 
 
 87. Hydrochloric and hydrofluoric acid gases are per- 
 fectly transparent in the test-tube, but as soon as they escape 
 into the air, they attract particles of moisture, in company 
 with which they condense into clouds. Hydrobromic and 
 hydriodic acid gases also yield clouds in moist air, but they 
 are generally accompanied by the brown vapor of bromine 
 or the violet vapor of iodine. 
 
 88. The presence of fluorine in a substance (giving rise 
 to the evolution of hydrofluoric acid) may be confirmed by 
 placing a little of it, in fine powder, upon a slip of glass, 
 moistening it with strong sulphuric acid, and warming it 
 gently for a minute or two. After cooling, the slip of glass is 
 thoroughly washed, wiped dry, and held so that the eye may 
 glance over its polished surface, when the spot previously 
 
 * A very convenient supply of portable gas is now furnished by 
 Mr. Orchard, of High Street, Kensington, compressed in safe 
 
 -n7rr>nfrV,t_^T.r,Ti ^-trl i'n/1 ova oa/.li n t a i ni r, cr 1* nnltin foot r>f rrac 
 
TEST FOR CHLORATES. 97 
 
 occupied by the substance will be found to have entirely lost 
 its polish if fluorine be present. 
 
 The action of hydrofluoric acid upon the silica contained 
 in glass, results in the formation of fluoride of silicon gas, 
 which is decomposed when brought into contact with water, 
 depositing opaque silica. 
 
 89. If fluorine be detected, the particular form in which 
 it is present remains to be decided. 
 
 Uncombined Fluorine, F, if known at all, exists only in 
 the state of gas. 
 
 Hydrofluoric Acid, HF, never occurs in the solid state. 
 The commercial acid is a solution in water, always known 
 by its pungent odor and corrosive action on glass. 
 
 The only compounds of fluorine which are at all common, 
 are 
 
 Fluor-spar, composed of fluorine and calcium. 
 
 Kryolite, which contains fluorine, aluminium, and sodium. 
 
 Fluor Spar or Fluoride of Calcium has been described 
 at (59). 
 
 Kryolite, Na 3 AlF 6 , is a white opaque mineral, generally in 
 rectangular masses. It is insoluble in water, and but slightly 
 attacked by hydrochloric or nitric acid. The powdered min- 
 eral, moistened with hydrochloric acid and exposed on a 
 clean platinum wire (74), colors the flame intensely yellow. 
 
 When heated with strong sulphuric acid, kryolite is dis- 
 solved ; if the solution be further heated, it becomes milky, 
 but the milkiness disappears, if the acid liquid, after cooling, 
 is mixed with much water and boiled. 
 
 90. Solid chlorates become yellow or red when moistened 
 with concentrated sulphuric acid, and slowly evolve, even in 
 the cold, a yellow gas (chloric peroxide) resulting from the 
 decomposition of the chloric acid, and having a very pecu- 
 liar odor. 
 
 Great care is necessary in applying heat, since the explo- 
 sive decomposition of the chloric peroxide sometimes shat- 
 ters the tube. 
 
98 HYPOCHLORITES. 
 
 A solution containing a chlorate becomes yellow when 
 heated with strong hydrochloric acid, emitting an odor re- 
 sembling chlorine. 
 
 Solution of a chlorate will (if free from chloride) give no 
 precipitate with nitrate of silver until it has been acidulated 
 with dilute sulphuric acid and allowed to remain in contact 
 with metallic zinc for a minute or two. 
 
 Chloric Acid, HC1O 3 , is not commonly met with. It is a 
 strongly acid liquid, which bleaches test-papers, and evolves 
 an odor of chlorine, especially when heated. 
 
 The only chlorates which are at all common, are those of 
 potash -and baryta, which have been described at p. 82 and 
 p. 70 respectively. 
 
 91. The odor of chlorine is perceived if the substance un- 
 der examination is common saltpetre, which always contains 
 some chloride. See Nitre (p. 81) and Nitrate of Soda (p. 88). 
 
 The compounds of hypochlorous acid also evolve chlorine 
 when heated with sulphuric acid. 
 
 Hypochlorous Acid itself exists either as a yellow explo- 
 sive gas, C1 2 0, or an aqueous solution, HC1O(?), of strong 
 chlorous odor and great bleaching power. 
 
 Solutions of the hypochlorites give a dark brown pre- 
 cipitate of binoxide of manganese on adding sulphate of 
 manganese. 
 
 The only hypochlorite commonly met with is the Hypo- 
 chlorite of Lime, Ca2Clo, which occurs in the solution of 
 Chloride of Lime of commerce, described at p. 74. 
 
 Hypochlorite of Soda, NaCIO, exists in the Chloride of 
 Soda, which is sold only in solution, and is described at p. 89. 
 
 92. To be sure of the presence of iodine, add to a solu- 
 tion of the substance to be tested a few drops of thin starch 
 (353) and a little concentrated nitric acid ; the nitrous acid 
 present in this will liberate the iodine, which colors the 
 starch blue. 
 
 93. Uncombined Iodine, I, is met with in shining black 
 scales which have a peculiar odor, somewhat resembling 
 
IIYDKOSULPIIURTC ACID. SULPHIDES. 99 
 
 chlorine. It stains the fingers brown, and is converted into 
 a splendid violet vapor when heated. 
 
 The only iodides likely to be met with in ordinary analysis 
 are those of potassium (77), iron (45), lead (14), mercury 
 (31), and arsemr (35). 
 
 94. To recognize the carbonic acid gas, dip a glass rod 
 into lime-water, and introduce it, with the clear drop of 
 lime-water suspended from it, into the mouth of the test- 
 tube, when the drop will immediately become coated with an 
 opaque film of carbonate of lime, which will disappear again 
 if exposed for some time to the action of the gas. 
 
 95. UncomMned Carbonic Acid is met with in ordinary 
 analysis, either in the state of gas, C0 2 , or dissolved in water, 
 H 2 C0 3 (?), and may be recognized by its faint odor, its fee- 
 bly reddening blue litmus paper, and its causing a milky 
 precipitate with lime-water, which disappears when the acid 
 is added in excess. 
 
 The carbonates most commonly met with are those of lime 
 (G9), soda (80), potash (77), ammonia (75), baryta (65), 
 magnesia (9), iron (45), zinc (53),'Zead (14), and copper 
 (27). 
 
 96. To be sure of the presence of hydrosulphuric acid, 
 spot a piece of filter-paper with solution of acetate of lead 
 or nitrate of silver, which will be blackened when exposed 
 to the action of that gas. 
 
 97. Hydrosulphuric Acid, H 2 S, itself is met with in 
 analysis, either in the form of gas or of a solution in 
 water, which smells of the gas and blackens acetate of lead 
 and nitrate of silver. 
 
 Many of the sulphides evolve hydrosulphuric acid when 
 they are heated with hydrochloric acid. The most important 
 are those of iron (45), antimony (39), ammonium (75), lead 
 (14), zinc (53), potassium, and calcium. 
 
 Sulphide of Potassium, K 2 8, is generally in brown frag- 
 ments, which easily become moist on exposure to air, and 
 
 smell strono-lv of hvflro.milnhnrip juMrL Tt dissolves pnsilv in 
 
100 PRUSSIAN BLUE TEST. 
 
 water, and the solution generally becomes milky when mixed 
 with hydrochloric acid, from the deposition of a little sul- 
 phur, due to the presence either of bisulphide of potassium 
 or of hyposulphite of potash. 
 
 Sulphide of Calcium, CaS, occurs in the soda-waste of the 
 alkali-works, as a nearly black substance, partly dissolved by 
 boiling water, yielding an alkaline solution. Dilute hydro- 
 chloric acid does not entirely dissolve it, but leaves a dark 
 residue containing carbonaceous particles. 
 
 Ultramarine is a blue powder which becomes white and 
 evolves hydrosulphuric acid when heated with hydrochloric 
 acid. It contains alumina, silica, sulphur, sodium, and iron. 
 
 98. To acquire familiarity with the odor of hydrocyanic 
 (prussic) acid, heat a little solution of ferrocyanide of potas- 
 sium (yellow prussiate of potash) with dilute sulphuric acid, 
 when pure hydrocyanic acid will be evolved. 
 
 In order to be sure of the presence of hydrocyanic acid, 
 add to a solution of the substance a few drops of solution of 
 sulphate of iron and a slight excess of potash ; shake the 
 precipitate for a few moments with the air in the tube,* and 
 add an excess of hydrochloric acid, when a blue precipi- 
 tate, or a decided blue or green color, pervading the liquid, 
 will indicate the presence of hydrocyanic acid, or of a cya- 
 nide. 
 
 In this test, the ferrous oxide and the potash, acting upon 
 the hydrocyanic acid, produce ferrocyanide of potassium ; 
 when the hydrochloric acid is added, it dissolves the ferric 
 oxide produced by the action of the air, and the ferric 
 chloride so produced, coming into contact with the ferro- 
 cyanide of potassium, produces ferrocyanide of iron or Prus- 
 sian blue. 
 
 If the cyanogen were originally present as a ferrocyanide 
 or a ferridcyanide, the sulphate of iron would at once produce, 
 
 * A drop or two of perchloride of iron (ferric chloride) will answer 
 the same purpose as shaking with air. 
 
FULMINATE OF MERCURY. 101 
 
 in the former case, a comparatively light blue precipitate, in 
 the latter, a dark blue. 
 
 99. Hydrocyanic Acid itself, HCN, is met with in aque- 
 ous solution only, recognizable by its odor, its very faintly 
 reddening; blue litmus paper, and by the above test. 
 
 The principal compounds of cyanogen, which evolve the 
 odor of hydrocyanic acid when they are heated with hydro- 
 chloric acid, are cyanide of potassium (77), ferrocyanide 
 (77), and ferridcyanide (77) of potassium, sulphocyanide of 
 potassium, cyanide of mercury (31), fulminate of mercury. 
 
 Sulphocyanide of Potassium, KCNS, forms white needle- 
 like crystals, which become moist in the air and dissolve 
 very easily in water. Perchloride of iron added to the 
 solution gives a deep blood-red color. Heated with hydro- 
 chloric acid, the sulphocyanide deposits a yellow precipitate, 
 and evolves a peculiar offensive gas which burns with a blue 
 flame. 
 
 Fulminate of Mercury, HgC 2 N 2 O 2 , is met with as a grayish 
 crystalline powder which is easily exploded by friction or 
 percussion. If placed on a slip of ghiss and touched with a 
 lighted match, it burns rapidly with a bright flash, and coats 
 the glass with metallic mercury. It is sparingly dissolved 
 by boiling water, but is readily soluble in hydrochloric acid. 
 
 Cyanide of Mercury has been already noticed at (31). 
 
 Since potash does not decompose the cyanide of mercury, 
 it is necessary, before applying the Prussian blue test de- 
 scribed above, to separate the mercury by slightly acidulating 
 the solution with hydrochloric acid, and introducing a piece 
 of zinc ; in the course of a few minutes the solution may be 
 poured off and tested with sulphate of iron, potash, and 
 hydrochloric acid, as above directed. 
 
 100. If there be any doubt whether the odor is that of 
 sulphurous acid, place a piece of zinc in the acid liquid, when 
 the hydrogen which is disengaged by its action upon the 
 hydrochloric acid will convert the sulphurous into hydro- 
 sulnhuric acid, which mav be re^o^nized bv its odor and bv 
 
102 -SULPHURIC ACID. 
 
 its blackening paper spotted with solution of acetate of lead 
 or nitrate of silver. 
 
 Sulphurous Acid itself is met with either as a gas, S0 a , 
 or a solution in water, H 2 S0 3 (?), always recognizable by its 
 odor. The principal commercial salt of sulphurous acid, 
 the sulphite of soda, has been described at p. 89. 
 
 Hypo sulphurous Acid is not known to exist in an uncom- 
 bined state. Its only common form of combination, the 
 hyposulphite of soda, has been described at p. 89. 
 
 101. Small quantities of sulphuric acid (in the form of 
 sulphates) are very commonly found as an impurity in com- 
 mercial salts, so that if this precipitate be scanty, the analyst 
 must hesitate before pronouncing sulphuric acid to be an 
 essential constituent of the salt. Sulphuric acid will also be 
 detected in a solution which has been made with nitric acid, 
 whether the sulphur existed in the original substance as a 
 sulphide, sulphite, hyposulphite, or sulphate. 
 
 102. Sulphuric Acid itself (sulphuric anhydride, S0 3 ), 
 is not commonly met with, except in combination with 
 water. 
 
 Hydrated Sulphuric Acid or Oil of Vitriol, H 2 SO 4 , is a 
 heavy, oily liquid which has usually a brownish color due 
 to the presence of organic matter. If it be poured into a 
 little water in a test-tube, much heat is developed. 
 
 The Nordhausen or Saxon Sulphuric Acid emits fumes 
 when the bottle is opened, and hisses slightly when poured 
 into water. 
 
 Diluted Sulphuric Acid strongly reddens blue litmus 
 paper. If a piece of white paper be moistened with it, and 
 dried at a gentle heat, it assumes an intensely black color, 
 the paper being carbonized by the acid. 
 
 The numerous salts of sulphuric acid or sulphates have 
 been described in the notes referring to their respective 
 metals. 
 
 102or. A white precipitate by nitrate of baryta, soluble 
 in dilute nitric acid, indicates either carbonic acid (when 
 
SILVER PRECIPITATES. 103 
 
 the precipitate would effervesce with the acid), phosphoric, 
 oxalic, boracic, silicic, sulphurous, or hyposulphurous acid. 
 These will all be detected in the subsequent part of 
 Table H. 
 
 103. If possible, the precipitate produced by nitrate of 
 silver should be allowed to settle, and the liquid should be 
 poured off before boiling the precipitate with nitric acid. 
 
 Cold nitric acid dissolves all the common precipitates pro- 
 duced by nitrate of silver, except the chloride, sulphide, and 
 cyanide, the two latter requiring to be boiled with the acid. 
 
 Cyanide of silver, when washed (1C), is dissolved by heat- 
 ing with solution of potash, which converts chloride of silver 
 into the brown oxide of silver, but does not dissolve it. 
 
 Several other less common silver precipitates, however, 
 are also insoluble in nitric acid, such as iodide (yellow), bro- 
 mide, ferrocyanide, ferridcyanide (brown red), and sulpho- 
 cyanide of silver. 
 
 If the washed silver precipitate be shaken with ammonia, 
 the iodide (whitened by the ammonia) and ferrocyanide are 
 undissolved, whilst the others are dissolved by ammonia. 
 
 104. Since chlorides are commonly found as impurities 
 in commercial salts, and small quantities give a comparatively 
 large precipitate with nitrate of silver, great care is requisite 
 before concluding that the substance under examination is 
 really a chloride. 
 
 The presence of a chloride may be confirmed by heating 
 the original substance with dilute sulphuric acid and black 
 oxide of manganese, when chlorine gas will be evolved, which 
 may be recognized by its odor and by its bleaching moistened 
 litmus paper.* 
 
 Bromides would evolve brown vapors of bromine having 
 
 * Corrosive sublimate (mercuric chloride) evolves very little 
 chlorine when heated with diluted sulphuric acid and black oxide 
 of manganese, and does not evolve hydrochloric acid when heated 
 with strong sulphuric acid. 
 
104 CHLORIDES. SILVER PRECIPITATES. 
 
 an intolerable odor and imparting an orange color to moist 
 starch. 
 
 Iodides would give violet vapors of iodine turning moist 
 starch blue. 
 
 105. Uncombined Hydrochloric Acid, HC1, is usually 
 met with in a state of solution in water. Concentrated hy- 
 drochloric acid, if pure, is colorless, but the common acid 
 has a yellow color due to iron. It fumes strongly in damp 
 air, and has a peculiar suffocating odor. When heated with 
 black oxide of manganese, it evolves abundance of chlorine, 
 distinguished by its irritating odor and its powerful bleach- 
 ing effect upon moist litmus paper. Diluted hydrochloric 
 acid does not fume in air, but also evolves chlorine when 
 heated with black oxide of manganese. 
 
 The Chlorides, which are precipitated by nitrate of silver 
 just as hydrochloric acid would be, have been noticed under 
 their respective metals. 
 
 106. For a test to confirm the presence of hydriodic acid, 
 see (92). 
 
 Hydriodic Acid, HI, in the free state is not commonly 
 met with. The Iodides, which behave with nitrate of silver 
 just like hydriodic acid, have been described, when of suffi- 
 cient importance, under their respective metals. 
 
 106. A black precipitate produced by nitrate of silver 
 indicates hydrosulphuric acid (97). A white precipitate 
 rapidly changing to orange brown and black indicates hypo- 
 sulphurous acid. See hyposulphite of soda (80). A brown 
 precipitate soluble in nitric acid may be arseniate of silver, 
 indicating arsenic acid (35), or oxide of silver, indicating 
 the presence of some caustic alkaline substance, such as pot- 
 ash, soda, or lime, dissolved in water (69, 77, 80). 
 
 A brown or red-brown precipitate insoluble in nitric acid 
 indicates ferridcyanogen. See ferridcyanide of potassium (77). 
 
 A white precipitate becoming brown or black when heated, 
 indicates boracic acid (Table H, col. 6) or sulphurous acid 
 (100). 
 
NITRIC ACID. 105 
 
 A white precipitate becoming brown when heated with 
 nitric acid, and then dissolving in ammonia which failed to 
 dissolve it at first, is ferrocyanide of silver (113). If the 
 nitrate of silver be not in excess, a blue color may be pro- 
 duced by the nitric acid. A red precipitate indicates chromic 
 acid (1*20), if the liquid be yellow or red, or arsenic acid if 
 the liquid be colorless. In both cases the precipitate is 
 soluble in nitric acid. 
 
 107. This test must be applied to a cold solution ; a con- 
 siderable quantity of sulphate of iron is necessary, and the 
 sulphuric acid must be poured slowly in, so that the bulk of 
 it may sink to the bottom of the tube, for if much heat be 
 produced by its mixing with the water, the brown compound 
 indicative of nitric acid will be decomposed. This brown 
 compound contains sulphate of iron, in combination with 
 nitric oxide which has been formed by the abstraction of 
 oxygen from the nitric acid, in order to convert another part 
 of the sulphate of iron (ferrous sulphate) into the persul- 
 phate (ferric sulphate). 
 
 108. If additional evidence of the presence of nitric acid 
 be required, the original substance, or even the solution, 
 when cold, may be mixed with about an equal volume of 
 concentrated sulphuric acid, a few copper filings or clippings 
 added, and heat applied, when brown fumes of nitric per- 
 oxide will be produced by the deoxidizing effect of the copper 
 upon the nitric acid liberated by the sulphuric acid.* 
 
 109. Nitric Acid itself (nitric anhydride, N 2 O 5 ) is ex- 
 tremely uncommon, except in combination with water. 
 
 Concentrated Nitric Acid, HNO 3 , when perfectly pure, is 
 colorless, but it generally has a yellow color caused by the 
 presence of nitric peroxide, NO 2 . It fumes in air, stains the 
 
 * The nitrites, or salts of nitrous acid, evolve brown vapors when 
 treated with sulphuric acid in the cold, and give a brown solution 
 with sulphate of iron and diluted sulphuric acid. 
 
106 NITRIC ACID. 
 
 skin yellow, and when poured upon copper or zinc causes 
 violent effervescence and disengagement of red fumes. 
 
 The Nitrous Acid of commerce is concentrated nitric acid 
 containing a larger proportion of nitric peroxide which im- 
 parts to it an orange-red color. Some specimens of strong 
 nitric acid have a green color, caused by the presence of 
 nitrous acid. 
 
 Diluted Nitric Acid (Aqua Fortis) of course reddens lit- 
 mus very strongly, and acts upon copper or zinc in the same 
 manner as the concentrated acid, but with less violence. 
 
 The salts formed by nitric acid, or nitrates, have been 
 described, when important, in the notes relating to the 
 individual metals. 
 
 110. If the original solution be neutral (18), it is not 
 necessary to add ammonia and acetic acid, but if it be acid 
 to test-paper, the free acid may prevent the formation of a 
 precipitate with perchloride of iron or with chloride of cal- 
 cium, so that it must be neutralized with ammonia, which 
 may be added till the liquid smells slightly of it, even after 
 being shaken with the thumb on the top of the tube, and 
 turns red litmus paper blue ; acetic acid may be added till 
 the smell of ammonia is no longer perceptible after shaking, 
 and the liquid reddens blue litmus paper. The solution is 
 then examined as in the Table. 
 
 Should any precipitate remain undissolved after acetic acid 
 has been added in excess, it is probably phosphate of iron 
 (p. 109), oxalate of lime (58), fluoride of calcium (59), 
 phosphate of alumina (p. 109), or phosphate of lead (p. 110). 
 
 111. A single drop of perchloride of iron is here recom- 
 mended, because the precipitate of phosphate of iron (ferric 
 phosphate) is soluble in an excess of the perchloride. 
 
 If a solid compound containing phosphoric acid is 
 throughly dried by heat, and strongly heated in a tube (17) 
 with a little metallic magnesium, the mass, after cooling, 
 evolves the peculiar fishy odor of phosphoretted hydrogen on 
 boiling with water. 
 
PHOSPHORIC ACID. 107 
 
 The most delicate test for phosphoric acid is molybdate of 
 ammonia, which produces, in the solution acidulated with 
 nitric acid (and free from hydrochloric acid), especially on 
 heating, a yellow precipitate containing phosphoric and 
 molybdic acids, and ammonia. 
 
 Care must be taken to avoid mistaking arsenic acid for 
 phosphoric acid (p. 46). 
 
 Ilia. A solution containing arsenious acid combined 
 with an alkali would also give a yellow precipitate soluble 
 in nitric acid, on addition of nitrate of silver, but the 
 absence of arsenious acid has been previously established 
 (Table A). 
 
 112. Phosphoric Acid itself (phosphoric anhydride, P S O 5 ) 
 is not commonly met with, because it cannot be exposed to 
 air without absorbing moisture and liquefying to a solution 
 of phosphoric acid. The ordinary solution of phosphoric 
 acid is a colorless liquid which strongly reddens blue litmus 
 paper. If it be mixed with a slight excess of ammonia, and 
 with a solution of sulphate of magnesia to which chloride of 
 ammonium and ammonia have been^ added, a white granular 
 precipitate of phosphate of magnesia and ammonia is pro- 
 duced, the formation of which is much promoted by stirring 
 the liquid (6). 
 
 Glacial Phosphoric Acid (or metaphosphoric acid, HPO 3 ) 
 forms transparent colorless masses which easily absorb water 
 from the air. It dissolves in cold water, and the solution 
 gives a white precipitate with nitrate of silver. If the solution 
 of the acid in water be boiled for some time, it is no longer 
 precipitated by nitrate of silver, unless a very little ammonia 
 is added, when it gives a yellow precipitate, the metaphos- 
 phoric acid having been converted into orthophosphoric or 
 tribasic phosphoric acid, H 3 PO 4 , by boiling with water. 
 
 Phosphoric acid might be found in a solution pre- 
 pared with nitric acid, as a result of the oxidation of phos- 
 phorus. 
 
 Ordinary {vitreous} phosphorus is easily recognized by its 
 
108 PHOSPHATES IDENTIFIED. 
 
 inflaming when rubbed or gently heated, when it burns with 
 a bright flame emitting thick clouds of anhydrous phosphoric 
 acid. 
 
 Amorphous or red phosphorus does not inflame when 
 rubbed, and requires a higher temperature to inflame it than 
 ordinary phosphorus. When heated in a small tube closed 
 at one end (17) it is converted into vapor which condenses 
 into drops of ordinary phosphorus on the cool sides of the 
 tube. 
 
 Phosphate of Soda has been described at (p. 89). 
 
 The presence of phosphoric acid in the phosphate of soda 
 may be confirmed by mixing the solution with ammonia, and 
 testing with the mixture of sulphate of magnesia, chloride of 
 ammonium, and ammonia. 
 
 The solution of phosphate of soda gives, with nitrate of 
 baryta, a white precipitate which is dissolved by dilute nitric 
 acid. 
 
 With nitrate of silver, it gives a yellow precipitate, soluble 
 in nitric acid. 
 
 Arseniate of soda, which much resembles the phosphate 
 (p. 46), gives a brown precipitate with nitrate of silver. 
 
 Phosphate of Soda and Ammonia, NaNH 4 HPO 4 , or micro- 
 cosmic salt, or phosphorus salt, forms colorless crystals, which 
 dissolve in water, yielding a solution which blues red litmus. 
 
 With nitrate of baryta and nitrate of silver, the solution 
 behaves like phosphate of soda. 
 
 With sulphate of magnesia, especially on stirring, it yields 
 the precipitate of phosphate of magnesia and ammonia. 
 
 When microcosmic salt is heated in a dry tube (17), it 
 fuses easily, boils, evolves much steam and ammonia (detected 
 by its odor), leaving a transparent glass of metaphosphate 
 of soda. 
 
 Phosphate of Lime and Superphosphate of Lime have been 
 noticed at (56). 
 
 To confirm the indication of the presence of phosphoric 
 acid in these salts, their solutions may be mixed with acetate 
 
PHOSPHATES IDENTIFIED. 109 
 
 of ammonia (prepared by mixing ammonia with a slight ex- 
 cess of acetic acid), and oxalate of ammonia added as long 
 as the precipitate of oxalate of lime is increased. The solu- 
 tion is then boiled, filtered, mixed with ammonia in slight 
 excess, and tested with the mixture of sulphate of magnesia 
 with chloride of ammonium and ammonia. 
 
 If phosphate of lime be made into a paste with concen- 
 trated sulphuric acid, and exposed on a platinum wire, in 
 the margin of a flame (70), the greenish flame of phosphorus 
 will be perceived in the dark. 
 
 Phosphate of Magnesia and Ammonia, or triple phosphate, 
 MgNH 4 PO 4 , is a white crystalline powder, which is insoluble 
 in water, but dissolves easily in hydrochloric acid. If the 
 hydrochloric solution be largely diluted with water, mixed 
 with ammonia in excess, and stirred with a glass rod, the 
 phosphate is repreeipitated in a granular form, especially 
 upon the lines of friction made by the glass rod. 
 
 The phosphate of magnesia and ammonia evolves ammo- 
 nia when boiled with potash. 
 
 Phosphate of Alumina, A1PO 4 , i.s insoluble in water, but 
 dissolves in hydrochloric acid. Potash precipitates it from 
 this solution, but an excess of potash redissolves it. Ammo- 
 nia also precipitates, but does not redissolve it. 
 
 If the solution of phosphate of alumina in hydrochloric 
 acid be mixed with a solution of tartaric acid, and afterwards 
 with an excess of ammonia, the solution will remain clear, 
 and the phosphoric acid may be detected by the mixture of 
 sulphate of magnesia with chloride of ammonium and am- 
 monia. 
 
 With strong sulphuric acid, in a flame, phosphate of alu- 
 mina behaves like phosphate of lime. 
 
 Phosphate of Iron, FePO 4 , is insoluble in water, but 
 soluble in hydrochloric acid, giving a yellow solution. On 
 mixing this with acetate of ammonia (prepared by mixing 
 ammonia with a slight excess of acetic acid), the phosphate 
 of iron is separated as a white precipitate. 
 
110 FERROCYANIDES IDENTIFIED. 
 
 If the hydrochloric solution of the phosphate of iron be 
 mixed with ammonia in excess, a brownish precipitate of 
 basic phosphate of iron is obtained ; by boiling this with 
 sulphide of ammonium, the iron is converted into (black) 
 sulphide of iron, and the phosphoric acid is dissolved as 
 phosphate of ammonia, and may be detected in the filtered 
 solution by sulphate of magnesia, mixed with chloride of 
 ammonium and ammonia. 
 
 Phosphate of Lead is white, insoluble in water, and not 
 easily soluble in hydrochloric acid, but diluted nitric acid 
 dissolves it ; ammonia added to this solution precipitates the 
 phosphate of lead, and acetic acid does not redissolve it. 
 
 By boiling the phosphate of lead with sulphide of ammo- 
 nium, the phosphoric acid is converted into phosphate of 
 ammonia, and may be detected in the filtered solution, with 
 the mixture of sulphate of magnesia with chloride of ammo- 
 nium and ammonia. 
 
 113. Ferrocyanogen is the name given to the group 
 C 6 N 6 Fe containing carbon, nitrogen, and iron, which is sup- 
 posed to exist in the ferrocyanide of potassium, and in other 
 ferrocyanides, though it has never been obtained in the sepa- 
 rate state. 
 
 Hydroferrocyanic (or ferrocyanic) Acid, H 4 C 6 N 6 Fe^ is 
 not at all a common substance. It is crystalline, and easily 
 soluble in water. When the solution is boiled, it evolves 
 the odor of hydrocyanic acid, and deposits a white preci- 
 pitate of cyanide of iron, which rapidly turns blue by 
 oxidation. 
 
 Ferrocyanide of Potassium has been described at (p. 84). 
 Its solution gives, with nitrate of silver, a nearly white pre- 
 cipitate of ferrocyanide of silver, which is not dissolved by 
 ammonia. 
 
 If this precipitate be warmed with dilute nitric acid, it is 
 converted into the orange-red ferridcyanide of silver, and is 
 then dissolved by ammonia, with exception of a few flakes 
 of peroxide of iron. 
 
TESTS FOR OXALIC ACID. Ill 
 
 Sulphate of iron causes a blue precipitate in solution of 
 ferrocyanide of potassium. 
 
 Ferrocyanide of Iron, or Prussian Blue, Fe & 12CN, is not 
 dissolved by water or dilute acids. It may be identified by 
 boiling it with potash, which leaves brown peroxide of iron 
 undissolved, and yields a solution of ferrocyanide of potas- 
 sium which may be filtered, neutralized with hydrochloric 
 acid, and tested with perchloride of iron. 
 
 Ferrocyanide of Copper, or Ifatchett's Brown, Cu 2 Fe6CN, 
 has a brown-red color, and is insoluble in water, and in 
 dilute acids. It is decomposed by boiling with potash, into 
 black oxide of copper and ferrocyanide of potassium, which 
 may be tested as in the case of Prussian blue. 
 
 114.* In order to obtain confirmatory evidence of the 
 presence of oxalic acid, shake a little of the original sub- 
 stance with diluted sulphuric acid (which does not cause 
 effervescence with oxalic acid), and throw in a little pow- 
 dered binoxide of manganese, when carbolic acid will escape 
 with effervescence, especially if a gentle heat be applied, and 
 may be recognized by the lime-water test (04). 
 
 115. Oxalic Acid, H 2 C 2 O 4 .2Aq., itself forms colorless 
 prismatic crystals, which dissolve easily in water, and yield 
 a strongly acid solution. . 
 
 When heated with strong sulphuric acid, oxalic acid dis- 
 solves with effervescence, evolving carbonic acid and car- 
 bonic oxide gases, the latter of which burns with a blue flame 
 on approaching the mouth of the tube to a flame. 
 
 With nitrate of baryta, a strong solution of oxalic acid 
 gives, on stirring with a glass rod, a granular precipitate of 
 oxalate of baryta, which dissolves in diluted nitric acid. 
 
 With nitrate of silver, solution of oxalic acid gives a white 
 
 * Ferrocyanide of potassium may also give, with chloride of cal- 
 cium, a precipitate of the double ferrocyanide of calcium and potas- 
 sium, which might be mistaken for oxalate of lime, since it is in- 
 soluble in acetic acid, but soluble in hydrochloric acid, from which 
 ammonia reprecipitates it. 
 
112 BORACIC ACID IDENTIFIED. 
 
 precipitate of oxalate of silver, which is soluble in diluted 
 nitric acid. 
 
 When heated in a dry tube (17), oxalic acid melts very 
 easily, and is entirely converted into vapor, a part of 
 which condenses on the sides of the tube in fine transparent 
 needles. 
 
 The Oxalates commonly met with are the acid oxalate of 
 potash (p. 85), oxalate of ammonia (75), and oxalate of lime 
 (58). 
 
 116. This test for boracic acid depends upon its singular 
 property of coloring orange-red the dye known as turmeric ; 
 but this property belongs only to free boracic acid, so that if 
 it be combined with a base, it is necessary to liberate it by 
 adding hydrochloric acid, until the solution reddens blue lit- 
 mus paper. A large excess of hydrochloric acid must be 
 avoided, since it is liable to carbonize the paper on drying. 
 
 The paper may be dried by waving it above the flame so 
 as not to scorch it, or by gently warming it upon a slip of 
 glass. 
 
 To obtain confirmatory evidence of the presence of boracic 
 acid, mix the substance under examination with strong sul- 
 phuric acid; add alcohol, and inflame the mixture, either 
 upon a glass rod dipped into it, or on a slip of glass, or in a 
 small evaporating dish, in the latter case stirring it with a 
 glass rod. Boracic acid imparts a decided green color to the 
 flame, especially at the edges. 
 
 11*7. Boracic Acid itself (anhydrous boracic acid, B 2 3 ) 
 is not commonly met with. It forms glassy fragments, trans- 
 parent when freshly prepared, but becoming opaque when 
 kept. It is powdered with great difficulty, and appears at 
 first to be insoluble in water and acids, but after boiling with 
 water for a short time, a little of it is dissolved, yielding a 
 solution which turns blue litmus paper violet, and stains 
 turmeric paper, which has been dipped into it and dried, 
 orange-red, becoming green when moistened with potash. 
 
 Glassy boracic acid dissolves easily when heated with potash. 
 
SILICIC ACID DETECTED. 113 
 
 Crystallized (or hydrated) Boracic Acid, 3H 2 O.B 2 O 3 , forms 
 white scaly or feathery crystals, which dissolve in boiling 
 water, and are deposited again when the solution cools. The 
 solution behaves, with litmus and turmeric papers, as stated 
 above. Placed on the point of a knife or on a platinum wire 
 (74), and heated in the margin of a flame (70), crystals of 
 boracic acid color the flame green, a part of the acid being 
 converted into vapor in the presence of the water. The 
 crystals are dissolved by boiling alcohol, and the solution 
 burns with a fine green flame. 
 
 The impure boracic acid imported from Tuscany, always 
 contains considerable quantities of ammonia and sulphuric 
 acid, as impurities. 
 
 The only common borates are Borax, or Biborate of Soda 
 (p. 89), and the mineral Boronatrocalcite, which is composed 
 of boracic acid, soda, lime, and water, and is imported from 
 Peru under the name of Borate of Lime. 
 
 Boronatrocalcite* occurs in soft earthy masses ; it is dis- 
 solved to a slight extent by water, and entirely by hydro- 
 chloric acid. If it is dissolved in a small quantity of hydro- 
 chloric acid, ammonia will cause a precipitate of borate of 
 lime; but if much acid be present, the chloride of ammonium 
 formed will be sufficient to prevent the precipitation, since 
 borate of lirne is soluble in chloride of ammonium. 
 
 118. To detect silicic acid, the solution which has been 
 acidified with hydrochloric acid is evaporated to dryness^ 
 (i. e., until no more liquid remains) in a dish (84) ; the latter 
 is allowed to cool, and some diluted hydrochloric acid poured 
 into it. The dish is again gently heated, and its contents 
 stirred with a glass rod ; when nothing more appears to dis- 
 solve, the contents of the dish are poured into a test-tube. 
 If silicic acid is present, semi-transparent flakes will be 
 
 * Na 2 0.2B 2 3 2(Ca0.2B 2 3 ).lSAq. 
 
 f When a considerable quantity of silicic acid is present, the 
 liquid becomes a jelly at a certain stage of the evaporation. 
 
114 CHROMIC ACID. 
 
 seen in the liquid, giving it a peculiar opalescent appear- 
 ance. 
 
 The silicic acid may be filtered off, and the solution testec\ 
 for potassium and sodium according to Table F, p. 77. 
 
 The only common substance which is likely to be mistaken 
 for silicic acid in this test is sulphate of lime, which is not 
 immediately redissolved by hydrochloric acid after evapora- 
 tion to dryness, though continued heating with the acid will 
 dissolve it. But the sulphate of lime is more opaque, and is 
 generally left as a crystalline powder, which sinks much 
 more readily than the silicic acid. Should there be any 
 doubt, the insoluble part may be allowed to settle in the 
 tube, washed twice, by decantation (16) and heated with a 
 little potash, which will easily dissolve silicic acid, but riot 
 sulphate of lime. 
 
 119. The common forms of silicic acid, as well as the 
 more frequently occurring silicates, are insoluble in water 
 and in diluted acids, and will therefore be noticed here- 
 after. 
 
 The only silicates which are soluble in water are the 
 Silicate of Potash (p. 85), and Silicate of Soda (p. 90). 
 Even those silicates which are attacked by boiling with 
 diluted acid (such as the Zeolitic minerals, and various 
 slags), do not generally dissolve in the acid, but leave a 
 residue of gelatinous silicic acid, so that they will be noticed 
 together with substances insoluble in water and acids. 
 
 120. Chromic Acid itself, CrO 3 , forms needle-like crys- 
 tals of a crimson color ; they attract moisture readily from 
 air, and dissolve easily in. water; the solution gives a bright 
 yellow precipitate with acetate of lead, and a red precipitate 
 with nitrate of silver. 
 
 The chromates most commonly met with are chromate of 
 potash (61), bichromate of potash (61), chromate of baryta 
 C65"). and chromate of lead (n. %9}. 
 
EXAMPLES FOR PRACTICE. 
 
 115 
 
 121. Examples for Practice in Tables G and H. The 
 following substances may be analyzed for practice (10) : 
 
 Chalk (carbonate of lime) 
 Common salt (chloride of sodium) 
 Fluor spar (fluoride of calcium) 
 Chloride of lime 
 Sulphide of iron 
 Ferroeyanide of potassium 
 Hyposulphite of soda 
 Phosphate ot soda 
 
 Oxalic acid 
 
 Saltpetre (nitrate of potash) 
 Chlorate of potash 
 Iodide of potassium 
 Cyanide of potassium 
 Sulphite of soda 
 Sulphate of magnesia 
 Borax (biborate of soda) 
 
 Silicate of potash. 
 
116 
 
 TABLE I. 
 
 
 
 13 
 ti 
 
 d 
 
 o 
 
 rH 
 
 2 -S 
 
 PH 3 
 
 I! 
 
 rC^3 
 
 -" 
 
 
 P- 
 
 .-- 
 
 a 
 
 Ms 
 
 P 3 rj O 
 ^^ < 
 
 SSflS 
 
 .=g 
 
 ^5^ 
 
 li I jfjiii 
 
 "3 ?H "S -2 
 - I -S^H=- 
 
 02 I * O 
 
 S3 
 
 **^1 
 
 . 
 
 25), on a p 
 minutes (1 
 warm wat 
 
 3 rfB 
 
 o 
 
 03 
 
 s 
 
 
 1.2 l S 
 
 . 
 &* . Sp ; s*^^-f|^x^s|S) .i^I'Sx 
 
 f & ^'S 1 2 I -S5 B S fe o 3 o J~ 2 -J--^ 
 
 -go |^2^ to|-g |^| S ^S-g 1 " 
 
 fcC ^ S sc IT? to en 
 
HEATING ON PLATINUM FOIL. 
 
 117 
 
 EXPLANATIONS AND INSTRUCTIONS ON 
 TABLE I. 
 
 123. Mode of observing the action of heat upon substances 
 in contact with air. A small piece of platinum foil is very 
 convenient for this purpose. 
 
 It may be held in a pair of crucible tongs (fig. 37), or 
 upon a triangle of iron wire (fig. 38), one limb of which is 
 thrust through a cork for convenience in holding it when 
 hot. 
 
 Fia. 38. 
 
 FIG. 37. 
 
 Crucible Tougs. 
 
 Triangle. 
 
 The substance under examination should be placed at one 
 corner of the foil, so that the latter may not be rendered 
 entirely useless if the substance should corrode it. 
 
 A gentle heat should be 
 applied at first by holding 
 the foil a little above the 
 point of a flame. A stronger 
 heat may be afterwards ob- 
 tained by directing the blow- 
 pipe-flame upon the under 
 surface of the foil (fig. 39). 
 
 Compounds of lead, bis- 
 muth, tin, antimony, and arsenic should not be heated on 
 platinum foil, since these substances corrode it. 
 
 FIG. 39. 
 
118 
 
 PULVERIZATION. 
 
 FIG. 40. 
 
 . A piece of broken porcelain, or a small porcelain crucible, 
 may be used instead of platinum foil. 
 
 A small piece of thin Ger- 
 man glass tube open at both 
 ends will answer the same 
 purpose, especially if it be 
 slightly bent so that the sub- 
 stance may rest in it. The 
 tube should be so held that 
 one opening is considerably 
 higher than the other, and to 
 this higher opening the nose should be applied, in order to 
 detect the odor of sulphur, arsenic, &c. (fig. 40). 
 
 124. Reduction of substances to powder. Most substan- 
 ces can be crushed and afterwards ground to powder in a 
 pestle and mortar (fig. 41) of Wedgwood ware. A small spa- 
 tula (fig. 42) is used to scrape the powder out of the mortar. 
 
 FIG. 41. 
 
 FIG. 42. 
 
 Large fragments must first be broken up by the hammer 
 on an anvil. 
 
 FIG. 43. 
 
 An iron pestle and mortar are very con- 
 venient for crushing hard substances. 
 
 To prevent fragments of the substance 
 from flying about, a wooden cover (fig. 43) 
 should be placed over it, with a hole for 
 the handle of the pestle. 
 
 When the mortar is not at hand, sub- 
 stances of moderate hardness may be pow- 
 
POWDERING. SIFTING. 
 
 119 
 
 dered on a hard surface by rolling a thick bottle over 
 them. 
 
 An agate mortar and pestle (fig. 44) are used for the final 
 grinding of very hard substances. The agate pestle should 
 be provided with a handle made of hard wood, and fitted to 
 it by a brass cap (fig. 45). The powdering is very much 
 
 FIG. 44. 
 
 facilitated by mounting the pestle on a brass rod, which plays 
 in a ring attached to a stout wooden upright rising from a 
 heavy bed of hard wood in which the agate mortar is firmly 
 set (fig. 46). 
 
 Reduction of substances to FIG. 47. 
 
 powder is sometimes hastened 
 if the fragments are sifted out 
 from time to time, by rubbing 
 the powder lightly with the fin- 
 ger upon a piece of muslin tightly 
 stretched over the mouth of a 
 beaker (fig. 47 ) . The fragments 
 left on the muslin are returned 
 to the mortar. 
 
 For powdering small quantities of very hard substances, a 
 
120 
 
 FUSION ON PLATINUM FOIL. 
 
 steel diamond mortar (fig. 48) is employed, consisting of a 
 socket (a fig. 49), into which a steel cylinder open at both 
 ends (b) fits tightly. The substance to be powdered, in 
 small fragments, is dropped into the hollow cylinder, and the 
 solid steel cylinder (c) which fits the former exactly, being 
 placed upon it, it is struck sharply and repeatedly with a 
 heavy hammer. 
 
 FIG. 48. 
 
 Fia. 49. 
 
 125. Fusion of insoluble substances with carbonate of 
 soda. The substance should be reduced to an impalpable 
 powder, that is, to a powder in which no grit can be felt 
 (124), and intimately mixed with the carbonate of soda, also 
 in fine powder, either in a small mortar (fig. 41) or with a 
 knife upon a piece of paper. 
 
 The carbonate of soda employed for this fusion must have 
 been previously dried to expel its water of crystallization. 
 The fusion is easier when a mixture of carbonates of soda 
 and potash is employed. 
 
 The mixture is placed upon a piece 
 of platinum foil,* slightly bent up at 
 the edges (fig. 50), and heated mode- 
 rately at first to expel any moisture 
 which may be present. The foil is 
 then heated to redness, over a Bunsen 
 (fig. 51) or gauze (fig. 52) burner, or by 
 directing a broad blowpipe-flame upon 
 
 FIG. 50. 
 
 * A piece of foil 1^ in. long and l' in. wide, of such thickness as 
 to weigh seven grains, will be found suitable for the purpose. 
 
INSOLUBLE SUBSTANCES. 121 
 
 its under surface (fig. 39).* To obtain such a flame, the 
 blowpipe jet should be held a little away from the flame, so 
 that a broad divergent stream of air may be sent through it. 
 
 FIG. 51. Fia. 52. 
 
 Gauze burner. Bunsen's burner. 
 
 Since only a small quantity of the powder can be fused at 
 once upon the foil, it is advisable to add it in successive por- 
 tions, as each is melted, until a sufficient quantity of the sub- 
 stance has been employed. 
 
 When the mixture is very difficult to fuse, the blowpipe 
 flame must be directed down upon its surface after the lower 
 part has been fused. No violence must be employed to 
 detach the fused mass from the foil, but it should be soaked 
 in water as directed at (131). 
 
 A small platinum capsule (fig. 53) is very con- 
 venient for the fusion of insoluble substances. 
 
 NOTES TO TABLE I. 
 
 125ft. A substance insoluble in water and acids will 
 most likely be one of the following: carbon, sulphur, silica, 
 silicate of alumina (clay), fluoride of calcium, sulphate of 
 
 * It is better to support the platinum foil upon the triangle (fig. 
 38) than to hold it with the tongs, which generally contaminate 
 the substance with iron. 
 11 
 
122 SULPHUR. CARBON. 
 
 baryta, sulphate of lime, binoxide of tin, chloride of silver, 
 sulphate of lead or chrome-iron-ore. 
 
 126. Sulphur is likely to be met with in several forms. 
 
 Crude Sulphur, as imported from Sicily and elsewhere, 
 forms grayish yellow lumps, and leaves a slight dark residue 
 when burnt. 
 
 Distilled Sulphur, used for the manufacture of gunpowder, 
 forms pure yellow lumps, and burns without residue. 
 
 Roll Sulphur (common brimstone) forms pure yellow 
 cylindrical sticks, also burning without residue. 
 
 These three varieties dissolve entirely, or nearly so, in 
 bisulphide of carbon. 
 
 flowers of Sulphur (or sublimed sulphur) is a fine yellow 
 powder, which burns without residue, but is not entirely 
 dissolved by the bisulphide of carbon, since it contains 
 a considerable proportion of the insoluble variety of 
 sulphur. 
 
 Milk of Sulphur (or precipitated sulphur} is a white im- 
 palpable powder which generally leaves a considerable white 
 residue (sulphate of lime) when burnt. 
 
 Viscous Sulphur, obtained by pouring hot melted sulphur 
 into water, has a brown color, and somewhat resembles 
 India-rubber; it becomes brittle when kept for a few hours. 
 Sulphur sometimes separates in viscous masses when the 
 sulphides of the metals are dissolved in nitric acid. 
 
 12*7. Carbon is met with in the forms of diamond, 
 graphite, vegetable charcoal, animal charcoal, coal, coke, 
 gas-carbon, lamp-black, soot. 
 
 Diamond is generally recognized by its extreme hardness, 
 rendering it capable of scratching glass and even steel. It is 
 unaffected when heated, in a small leaden or platinum cup, 
 with hydrofluoric acid, or a mixture of sulphuric acid arid 
 ammonium fluoride, which would dissolve the imitations of 
 diamond. It burns with difficulty in air, even when heated 
 in the blowpipe-flame, arid is best recognized by burning it in 
 oxygen, and detecting the carbonic acid produced, by means 
 
VARIETIES OF CARBON. 123 
 
 of lime-water. The mode of effecting the combustion 
 of the diamond is described in most works on Elementary 
 Chemistry. 
 
 Graphite, plumbago, or black lead is recognized by its 
 semi-metallic lustre, especially when rubbed with a hard sub- 
 stance, and by its greasy feeling between the fingers. It 
 burns away very slowly when heated in air, and generally 
 leaves a considerable residue of (brown) peroxide of iron. 
 
 Vegetable Charcoal (wood charcoal) may of course gene- 
 rally be recognized by its appearance. It glows readily 
 when heated in air, and leaves a small quantity of white 
 very light ash. 
 
 Animal Charcoal (bone-black, ivory-black, char) burns 
 pretty easily when strongly heated, but leaves a very large 
 earthy residue (phosphate and carbonate of lime). This 
 variety of charcoal effervesces slightly with hydrochloric acid, 
 which dissolves the phosphate and carbonate of lime, the 
 former being deposited as a white gelatinous precipitate on 
 mixing the filtered solution with ammonia in excess. 
 
 Coal evolves a tarry odor when heated, and furnishes a 
 coke which burns away with some (Tifficulty, leaving a mode- 
 rate ash consisting chiefly of silica and alumina, but having 
 a reddish-brown color (due to peroxide of iron) if much 
 iron-pyrites be present in the coal. 
 
 Coke of course behaves in the same way, but does not 
 evolve tarry odors. Both coal and coke burn vividly (defla- 
 grate) when thrown into melted nitre heated to redness. 
 
 Gas-carbon (the deposit which lines the interior of gas- 
 retorts) somewhat resembles coke in appearance, but is much 
 harder and more compact, having almost a metallic sound 
 when struck. It is very difficult to burn it in air, and a 
 high temperature is required to deflagrate it with nitre. 
 
 Lamp-black (spirit -block) is known by its dead black ap- 
 pearance and great lightness. It glows easily when heated 
 in air, and burns entirely away when pure, but commercial 
 lamp-black often leaves a considerable white ash. 
 
124 
 
 INSOLUBLE SUBSTANCES. 
 
 Soot may be recognized by its odor. It burns easily in 
 air. When boiled with solution of potash, it evolves an 
 odor of ammonia, derived from the destructive distillation of 
 the coal. 
 
 128. Chloride of Silver, AgCl, dissolves when heated 
 with ammonia ; if an excess of nitric acid be added to the 
 solution, white chloride of silver is reprecipitated, and be- 
 comes violet when exposed to daylight. 
 
 Chloride of silver also dissolves in solution of hyposulphite 
 of soda. 
 
 129. The presence of fluor-spar may be confirmed accord- 
 ing to (59). 
 
 130. Should the fused mass have a bright yellow color, it 
 is due to the formation of an alkaline chromate, and indicates 
 the presence of chromium. A dark green color, changing 
 to turquoise blue on cooling, is caused by manganate of soda, 
 and indicates the presence of manganese. 
 
 131. The platinum foil with the fused mass should be 
 
 placed, as soon as the mass has 
 set, in an evaporating dish (fig. 54) 
 containing about half an ounce 
 (four teaspoonfuls) of distilled wa- 
 ter. The dish is gently heated, 
 and the surface of the foil lightly 
 rubbed under the water, with a 
 glass rod rounded at the end, 
 until the mass has become de- 
 tached. The foil is then re- 
 moved, and the mass stirred with 
 the water, and crushed under 
 the glass rod until it is entirely 
 disintegrated ; the insoluble resi- 
 due is then collected on a filter. 
 
 132. Since the carbonate of soda (which lias been used 
 in the fusion) is liable to contain sulphuric acid as an impu- 
 rity, it is advisable to test it for that acid before concluding 
 
 FIG. 54. 
 
 Evaporation. 
 
TIN STONE. 125 
 
 that the sulphuric acid here detected really belongs to the 
 substance. 
 
 If the sulphuric acid be really present as an essential con- 
 stituent of the substance insoluble in water and acids, it must 
 exist in the form of sulphate of baryta, sulphate of strontia, 
 sulphate of lime, or sulphate of lead. 
 
 133. Sulphate of Baryta, BaSO 4 , or heavy-spar (some- 
 times called barytes or cawk) occurs naturally in a transparent 
 colorless form, crystallized in prisms. It is more commonly 
 opaque, and of a brownish color. By a skilful operator the 
 barium may be detected in it by the blowpipe test (276). 
 
 Artificial sulphate of baryta is an earthy white powder. 
 
 Sulphate of Strontia, SrSO 4 , or celestine usually occurs in 
 bluish opaque masses with a fibrous structure, but it is some- 
 times white or yellowish. The blowpipe test will indicate the 
 strontium (244). 
 
 Sulphate of Lime and Sulphate of Lead have been described 
 at (69) and (14) respectively. 
 
 134. It sometimes happens that a slight brown precipi- 
 tate of platinum sulphide is produced here, due to the corro- 
 sion of the platinum foil during the fusion. 
 
 135. If tin be present in the insoluble substance, it will 
 probably also be detected in the residue left on treating the 
 fused mass with water. 
 
 The only compound of tin likely to be found here is the 
 Binoxide of Tin, SnO 2 (tinstone, stannic acid, putty -powder}, 
 which occurs naturally either in separate crystals (stream-tin 
 ore) or in large masses (mine-tin ore) of inferior purity. It 
 is usually dark-colored, heavy, and very hard, scratching 
 glass like quartz. 
 
 The presence of tin is easily confirmed by the blowpipe 
 (241). 
 
 Artificial binoxide of tin is a white powder which becomes 
 yellowish when heated. 
 
 Putty-poAvder commonly contains oxide of lead as well as 
 binoxide of tin. 
 
126 SILICON. 
 
 136. If antimony is present in the insoluble substance, 
 the greater part of it will probably be found, as antimoniate 
 of soda, in that portion of the fused mass which is insoluble 
 in water. 
 
 Antimonic Acid, Sb 2 5 , the only insoluble compound of 
 antimony likely to be met with here, is a white powder which 
 assumes a yellow tint when heated. 
 
 137. For confirmatory evidence of the presence of silicic 
 acid, see (118, 119). 
 
 Silicon or silicium itself, Si, would have been converted 
 into silicic acid by the fusion with carbonate of soda. Its 
 commonest form is that of a dark powder which dissolves 
 when boiled with potash. If a little silicon be placed on a 
 piece of platinum foil and sharply heated by directing a blow- 
 pipe-flame upon the under surface of the foil, it eats a 
 hole in the metal, converting it into the fusible silicide of 
 platinum. 
 
 The so-called oxide of silicon which occurs in the residue 
 left when cast iron is dissolved in hydrochloric acid, is a 
 gray, very light powder, which is easily dissolved with 
 effervescence when heated with solution of potash, hydrogen 
 being evolved, which is recognized by its inflammability. 
 
 Silicic Acid or silica, SiO 2 , is met with in a variety of 
 forms, of which the following are the most important. 
 
 Sand is of various shades of color. It is generally found 
 to contain a small quantity of alumina (in the form of clay) 
 and a little iron. 
 
 Flint is known by its characteristic appearance. 
 
 Quartz occurs in rounded pebbles or in transparent masses, 
 sometimes of a pink color. It is also commonly met with 
 in well-defined six-sided prisms with pyramidal terminations. 
 Both quartz and flint scratch glass easily. 
 
 Chalcedony varies very much in color, its commonest form 
 is milk-white and opaque. 
 
 Soluble Silica is found in dull white earthy masses, or, in 
 volcanic districts, in porous lumps like pumice, often stained 
 
CLAY. 127 
 
 yellow with perchloride of iron. It is easily dissolved when 
 boiled with solution of potash. 
 
 COMMON SIMPLE SILICATES. 
 
 Names. Composition. 
 
 Clay Silicic acid, alumina, water. 
 
 Pumice Silicic acid, alumina. 
 
 Slate Silicic acid, alumina. 
 
 Steatite Silicic acid, magnesia. 
 
 Meerschaum Silicic acid, magnesia. 
 
 Iron slags Silicic acid, oxide of iron. 
 
 Electric calamine Silicic acid, oxide or zinc, water. 
 
 Clay* (silicate of alumina) occurs in various degrees of 
 purity, and may be generally recognized by its plasticity 
 when mixed with water. 
 
 By heating clay for some time with strong sulphuric acid, 
 a part of it is decomposed, and if, after cooling, the mixture 
 be diluted with water and filtered, it gives, when mixed with 
 excess of ammonia, the characteristic gelatinous precipitate 
 of alumina. 
 
 Pipe-clay and Kaolin are white, and consist of nearly pure 
 silicate of alumina. 
 
 Fire clay (Stourbridge clay) has a gray color, and con- 
 tains a little iron. Fire-brick (baked fire-clay) has a yel- 
 lowish hue, from the presence of ferric oxide. 
 
 Dinas fire-brick consists almost entirely of silica. 
 
 Common Clay has various shades of blue, yellow, and red, 
 and often contains considerable quantities of iron and lime. 
 
 Fuller's Earth is a brown clay containing iron. 
 
 Brick, earthenware, and porcelain, since they are com- 
 posed chiefly of baked clay, contain silicate of alumina, the 
 two former sometimes containing much iron. 
 
 When clay is fused, as directed in the table, the greater 
 
 * Kaolinite, which appears to form the basis of the varieties of 
 clay, has the composition Al 2 3 .2Si0. 2 .2Aq. 
 
128 SIMPLE SILICATES. 
 
 part of the silica is not found in the aqueous solution of the 
 fused mass (as is the case with most other silicates), but in a 
 gelatinous residue of silicate of alumina which is left undis- 
 solved by water, but dissolves in acids. 
 
 Pumice and Slate are known by their appearance. 
 
 Steatite, 3Mg0.4Si0 2 , Soap-stone, or French Chalk (sili- 
 cate of magnesia), is recognized by its peculiar soapy feel 
 when rubbed in the fingers. 
 
 Meerschaum, 2MgO.3SiO 2 .2Aq., is a white earthy mine- 
 ral, met with in rounded masses. 
 
 Iron Slag (silicate of iron) has been described at (p. 56). 
 
 Electric Calamine (hydrated silicate of zinc), or zinc 
 glance, 2ZnO.SiO 2 Aq., is usually grayish- white, with a glassy 
 lustre. When the mineral is boiled with hydrochloric acid, 
 the silica separates in the gelatinous state, and the zinc is 
 dissolved in the form of chloride. 
 
 138. It is of course unnecessary to examine for potas- 
 sium, sodium, and ammonium in this solution. 
 
 139. Any portion of the substance which has not been 
 finally powdered is likely to be left here. 
 
 140. Chrome-iron ore is never completely attacked by 
 the fusion, and may be recognized by fusing it on platinum 
 foil with carbonate of soda and nitrate of potash. On soaking 
 the foil in warm water, a yellow solution is obtained which 
 should be filtered, acidified with acetic acid, and tested with 
 lead acetate, which gives a yellow precipitate. The undis- 
 solved residue may be dissolved in strong hydrochloric acid 
 and tested for iron (44). 
 
 Carbon in some very incombustible forms, may also be left 
 here. Such carbon can only be consumed by protracted 
 heating in a muffle. 
 
 141. Examples for Practice in Table I. The following 
 substances may be analyzed for practice. See (10). 
 
 Fluor spar 
 Plaster of Paris 
 Binoxide of tin 
 
 Sulphate of baryta 
 Sulphate of lead 
 White sand. 
 
TABLE K. 
 
 129 
 
 1 1 1 i i 1 1 1 * ! 
 
 S * 1 1 a S 
 
 i . S- J 1 js 
 
 s o -g s 3 
 
 M *-g ^ 
 
 8-S 
 
 11 
 
 +j 
 
 
 a" 
 
 * 
 
 8 
 
 
 <S 
 
 ^ S " x ^- r ^ 
 
 ^ ~ 
 
 - - 
 
 1 
 
130 
 
 TABLE L. 
 
 
 
 3 
 
 o 
 
 03 
 00 
 
 d 03 
 
 o 
 <u g 
 3 ^ 
 
 fi I 
 
 
 6 g | . 
 
 fl '5 '' 
 
 fi = 
 
 2 ^ 
 
 wd 
 
 9 
 
 fc B) 3 p a 
 
 - 
 
 s - -^ 
 
 I^IIJII 
 
 p, 
 
 5 -2 - x 'S 
 
 oS-Sf^ 1 I Ijl S 
 
 - * S =3 'S s^ ^ ^ ^ Q - '" - 
 
 is-l^l*^ 
 
 W SS 53 b S o- -S 
 
 s^g^'Ssf^ ^ 2sr -*^ 
 . &sS3^S^|?|Ii?i 
 
 ^ ^Sfi^O ^~'O"'~^-J3U"T.< 
 
 ^ S g M M 
 
 " O 
 
 
 
 
 95 W 
 
TABLES M AND N. 
 
 131 
 
 
 rt of the 
 LORic ACID 
 briskly w 
 ulverulen 
 bl Uric 
 
 To a p 
 lIvDuocii 
 and stir 
 White p 
 prob.a 
 
 12- 
 ft 8^ 
 
 l|S 
 111 
 
 ^.15 o 
 S ' 
 ^^1. 
 
 lit 
 8 
 
 r ft 
 
 o3 
 
 P. -. 
 
 O 3 
 
 2 I 
 
 3 
 
 S be 
 PH 'oj 
 
 : i 
 
 g^o 
 
 A very slight excess 
 Ived by further addi 
 Made by adding ace 
 
 a Sub 
 
 a 
 
 
 o 
 
 d 
 
 I 
 
 8 
 
 a 
 
 rH 
 
 i 
 
 3 
 
 16 
 
 ^ 
 
 1 
 
 tion 
 ce wi 
 SOD 
 ssary, 
 he ac 
 
 o 
 ta 
 
 a 
 O 
 
132 ORGANIC ACIDS. 
 
 NOTES TO TABLES K, L, M, AND N, 
 
 146. Much attention should be paid to the odor evolved 
 on heating the substance, since many organic acids may be 
 at once recognized in this way. The analyst is recommended 
 to render himself familiar with the characteristic odors by 
 heating small specimens of each of the organic acids. 
 
 Tartaric Acid evolves a sweetish odor, somewhat like that 
 of burnt sugar. 
 
 Citric Acid evolves a similar odor, but more pungent. 
 
 The compounds of Acetic Acid give the peculiar fragrant 
 odor of acetone. 
 
 Benzole Acid gives the aroma of frankincense. 
 
 Succinic Acid emits vapors which provoke coughing. 
 
 Hippuric Acid furnishes an odor resembling bitter 
 almonds. 
 
 Uric Acid evolves a smell of singed hair, in which a keen 
 scent will trace ammonia and hydrocyanic acid. 
 
 147. If the substance leaves no residue when heated, it 
 is not likely to contain any metal except ammonium or 
 mercury. 
 
 Ammonium may at once be sought by boiling the sub- 
 stance with solution of potash, which would evolve the pun- 
 gent odor of ammonia.* 
 
 Mercury would be detected by boiling the substance with 
 dilute hydrochloric acid and slips of metallic copper, which 
 would become coated with a silvery deposit, yielding globules 
 of mercury when dried and heated in a small tube. 
 
 Proceed to detect the acid, as in column 2, Table K. 
 
 148. The red color caused by acetic acid (due to the 
 formation of peracetate of iron or ferric acetate) should not 
 
 * It must be remembered that urea also evolves ammonia when 
 boiled with potash ; but urea, unlike ammonia, is not precipitated 
 
ACETIC ACID. ACETATES. 133 
 
 be bleached by chloride of mercury (in which it differs from 
 that caused by the hydrosulphocyanic acid). 
 
 To obtain confirmatory evidence of the presence of acetic 
 acid, heat the substance with alcohol and concentrated sul- 
 phuric acid, which should evolve the pleasant smell of acetic 
 ether, resembling that of cider. 
 
 149. Acetic Acid, HC 2 H 3 O 2 , itself is a colorless liquid, 
 having the acid smell of vinegar, without its aroma. It 
 evaporates when heated on a slip of glass, without leaving 
 any residue. 
 
 If acetic acid is carefully neutralized with ammonia or 
 carbonate of ammonia, and a little nitrate of silver added, a 
 crystalline precipitate of acetate of silver separates, especially 
 on stirring briskly with a glass rod. The silver is not 
 reduced to the metallic state on heating the precipitate with 
 the liquid (as would be the case with formic acid, which, in 
 other respects, might be mistaken for acetic). 
 
 Acetic acid yields a crystalline precipitate with mercurous 
 nitrate (protonitrate of mercury), if 'the mixture be stirred 
 briskly with a glass rod. 
 
 Acetic acid is also characterized by its property of acquir- 
 ing an alkaline reaction to red litmus, when boiled with 
 oxide of lead (litharge), in consequence of the formation of 
 the basic acetate of lead. 
 
 The most commonly occurring salts of acetic acid are 
 Acetate of Lead (14), Tribasic Acetate of Lead, Acetate of 
 Copper (27), Acetate of Alumina (51), Acetate of Iron, 
 Acetate of Potash, Acetate of Soda, and Acetate of Ammonia. 
 
 Tribasic Acetate of Lead (or Goulard's extract), Pb2C 2 
 H 3 O 2 .2PbO.Aq., is commonly sold in solution, though it may 
 be crystallized in needles. It has a sweet taste, and turns 
 red litmus paper blue. On breathing into a test-tube con- 
 taining a little of the solution, and shaking it up, a white 
 
134 FORMIC AND MECONIC ACIDS. 
 
 precipitate of carbonate of lead is produced. Addition of 
 common water to the solution also renders it milky. 
 
 Acetate of Iron (ferric acetate), Fe3C 2 H 3 O 2 , forms a deep 
 red solution, which is changed to yellow by hydrochloric 
 acid. When a solution of ferric acetate is mixed with three 
 or four times its volume of water and boiled, a brown pre- 
 cipitate of basic ferric acetate is deposited. 
 
 Acetate of Potash, KC 2 II 3 O 2 , is commonly sold in white 
 opaque fibrous masses, having a faint acetic odor, and easily 
 absorbing moisture from the air. It is very soluble in water, 
 and the solution gives a bright red color with perchloride of 
 iron. 
 
 When heated on platinum foil, acetate of potash fuses 
 easily, evolves inflammable vapors, and leaves a residue of 
 carbonate of potash, which is strongly alkaline to moistened 
 red litmus paper, and effervesces with hydrochloric acid. 
 
 Acetate of Soda, NaC 2 H 3 2 .3Aq., is sold either in moist 
 transparent crystals or in grayish fibrous masses which have 
 been fused. In other respects it resembles acetate of potash, 
 but the residue of carbonate of soda, which it leaves when 
 burnt on platinum foil, does not deliquesce in air like the 
 carbonate of potash. It is very fusible, and requires a high 
 temperature to decompose it. 
 
 Acetate of Ammonia, NH 4 C 2 H 3 O 2 , is generally met with 
 in solution ; on boiling it, the odors of acetic acid and am- 
 monia may be perceived. 
 
 150. Formic Acid, IICHO 2 , is a colorless liquid of pun- 
 gent odor, resembling that of acetic acid. It leaves no 
 residue when evaporated. When formic acid is heated with 
 nitrate of silver or bichloride of platinum, black deposits of 
 the metals are obtained, especially if a little ammonia is 
 added. 
 
 The formiates of potassium and sodium, when heated with 
 strong sulphuric acid, evolve carbonic oxide abundantly, 
 which burns with a blue flame on applying the mouth of the 
 tube to a light. 
 
TANNIC AND GALLIC ACIDS. 135 
 
 151. Meconic Acid, H 3 C 7 HO..3Aq., forms scaly crystals 
 which have commonly a brownish color, and dissolve with 
 difficulty in cold, but easily in hot water. Alcohol also dis- 
 solves them. 
 
 The red color produced by perchloride of iron with nie- 
 conic acid is not bleached by chloride of mercury (thus 
 distinguishing it from hydrosulphocyanic acid). 
 
 A solution of meconic acid which has been mixed with 
 excess of ammonia, gives a white precipitate with chloride of 
 calcium, which is soluble in acetic acid. 
 
 None of the meconates are of common occurrence. Meco- 
 nate of morphia is sometimes used in medicine. 
 
 152. Tannic Acid (or tannin), C J4 H 10 O 9 , is a yellowish 
 or brownish powder, which has a very astringent taste, and 
 dissolves pretty easily when shaken with cold water. 
 
 On adding potash or ammonia to a solution of tannic acid, 
 it becomes brown, especially if shaken with air. 
 
 Dilute sulphuric acid, added in considerable quantity, 
 causes a white precipitate in solution of tannic acid. When 
 the solution has been kept for some time, it fails to give this 
 precipitate. 
 
 The only tannate commonly met with is that of sesqui- 
 oxide of iron (ferric tannate) which exists in writing ink. 
 
 Ink may be identified by adding strong nitric acid, which 
 reddens it, and changes it to a clear yellow on boiling. On 
 adding excess of ammonia, the. rusty brown sesquioxide of 
 iron is precipitated. 
 
 153. Gallic Acid, HC 7 H 5 O., is a white or yellowish 
 powder composed of minute shining needles. It is not 
 visibly dissolved when shaken with cold water, but dissolves 
 readily on boiling, being deposited again in delicate needles 
 when the solution cools. 
 
 Potash or ammonia causes a red-brown color in a solu- 
 tion of gallic acid, which becomes much darker on shaking 
 with air. 
 
136 SUCCINIC AND HIPPURIC ACIDS. 
 
 There is no gallate of common occurrence. 
 
 154. Be quite sure that this brown precipitate is not the 
 peroxide of iron precipitated because the original solution 
 was alkaline. 
 
 Benzoic Acid, HC 7 H 5 O a , is commonly met with in white 
 feathery crystals, which are extremely light and have an 
 agreeable odor of incense. It has a peculiar sweetish pun- 
 gent taste, and is not easily dissolved by water. It dissolves 
 easily in ammonia, and is reprecipitated in feathery flakes on 
 adding excess of hydrochloric acid, if the solution be not too 
 dilute. 
 
 When gently heated in a tube, it fuses easily, and sub- 
 limes without leaving any residue of importance. Hippuric 
 acid (156) much resembles benzoic. 
 
 None of the benzoates are sufficiently common to require 
 special description. 
 
 155. The precipitate is of a much darker red-brown 
 color in the case of succinic than in that of benzoic acid. 
 
 Succinic Acid, H 2 C 4 H 4 O 4 , is a colorless crystalline acid, 
 which dissolves easily even in cold water. The solution 
 when mixed with excess of ammonia and chloride of barium, 
 does not give any precipitate ; but if alcohol be added, the 
 liquid deposits succinate of baryta as a white precipitate. 
 
 Succinic acid is characterized by its behavior when 
 heated; it first melts, and is then decomposed, evolving 
 vapors which produce violent coughing. It leaves a very 
 slight carbonaceous residue, which easily burns away. 
 
 No salt of succinic acid can be described as being com- 
 monly met with. 
 
 156. Hippuric Acid, HC 9 H 8 NO 3 , forms shining pris- 
 matic crystals which are nearly insoluble in cold water, but 
 dissolve readily on boiling, and are deposited as the liquid 
 cools. It is almost insoluble in ether, and may thus be dis- 
 tinguished from benzoic acid, which dissolves easily in ether. 
 
 When heated in a tube, hippuric acid melts and is decom- 
 nosed. evolving an asrreeable odor (of benzonitrile, CJLN) 
 
TARTARIC ACID. 137 
 
 resembling oil of bitter almonds, and leaving a carbonaceous 
 residue. 
 
 When heated with strong sulphuric acid, hippuric acid 
 blackens more easily, and evolves more sulphurous acid than 
 benzoic acid does. If hippuric acid be dissolved in potash 
 and evaporate to dryness, the residue evolves ammonia 
 when heated. Benzoic acid, being free from nitrogen, could 
 not furnish ammonia when thus treated. 
 
 The hippurates are not commonly met with. 
 
 157. The behavior of the precipitate of tartrate of lime 
 is very characteristic, and should be carefully observed. 
 
 When precipitated, as in Table L, from an ammoniacal 
 solution, it is flocculent or gelatinous, according to the 
 strength of the solution ; but if it be set aside for some time, 
 it becomes a granular crystalline precipitate. 
 
 The flocculent tartrate of lime dissolves easily in chloride 
 of ammonium, and is deposited again in a crystalline state if 
 the sides of the tube beneath the liquid be well rubbed with 
 a glass rod.* 
 
 Crystalline tartrate of lime does not dissolve when shaken 
 with chloride of ammonium, and not easily in acetic acid, 
 so that it might at first be mistaken for oxalate of lime; but 
 if it be dissolved in hydrochloric acid, and an excess of 
 ammonia added, it is not immediately reprecipitated, as 
 would be the case with oxalate of lime, but requires brisk 
 stirring with a glass rod, when it again separates in a crystal- 
 line state. 
 
 158. Tartaric Acid, U^CJIfl^ itself is sold either in 
 colorless crystals, or as a white powder. It dissolves readily, 
 even in cold water, giving a strongly acid solution. 
 
 When heated, tartaric acid melts, carbonizes, and evolves 
 a peculiar odor, somewhat resembling that of burnt sugar ; 
 
 * The tartrate of lime precipitated from tartar emetic does not 
 exhibit this disposition to become crystalline. 
 
138 TARTAKIC ACID. 
 
 the remaining carbon burns off without any residue if the 
 acid is pure. 
 
 When heated with strong sulphuric acid tartaric acid 
 soon gives a very black solution, and evolves a little carbonic 
 oxide, which burns with a blue flame on applying the mouth 
 of the tube to a light. 
 
 Lime-water, added in excess to a very small quantity of 
 solution of tartaric acid, gives a white precipitate of tartrate 
 of lime, soluble in chloride of ammonium. 
 
 A solution of tartaric acid, mixed with a small quantity of 
 chloride of calcium, gives no precipitate; but if potash be 
 gradually added, tartrate of lime is precipitated, which dis- 
 solves in an excess of potash, and is reprecipifated on boiling 
 the solution, dissolving again as it cools. 
 
 If much chloride of calcium be employed, some carbonate 
 of lime is precipitated by the carbonic acid in the potash, and 
 this does not dissolve in the excess of potash. 
 
 Acetate of lead, added to a solution of tartaric acid, pro- 
 duces a white precipitate of tartrate of lead, which is easily 
 soluble in ammonia. 
 
 If a solution containing tartaric acid be mixed with potash 
 in excess and permanganate of potash, the green color at 
 first produced will disappear on boiling, a brown precipitate 
 of manganic oxide being separated (see citric acid). 
 
 The salts of tartaric acid commonly met with, are Bitar- 
 trate of Potash, Tartrate of Antimony and Potash, .and 
 Tartrate of Potash and Soda. 
 
 Bitartrate of Potash has been described at (p. 83). 
 
 By dissolving it in a very small quantity of potash, and 
 adding a little chloride of calcium, the white precipitate of 
 tartrate of lime may be obtained, which dissolves in an 
 excess of potash, and is reprecipitated by boiling. 
 
CITRIC ACID. 139 
 
 Tartrate of Antimony and Potash has been noticed at (39). 
 
 Its solution in water is slightly acid, and gives, after a 
 short time, a white precipitate of teroxide of antimony on 
 adding ammonia; this may be filtered off, and the solution 
 tested with chloride of calcium (Io7). 
 
 Tartrate of Potash and Soda, or Rochelle salt, KNaC 4 H 4 
 O 6 .4Aq., forms large transparent prismatic crystals, which 
 dissolve easily in water. If the solution be slightly acidified 
 Avith acetic acid, and briskly stirred, a crystalline precipitate 
 of bitartrate of potash is deposited. 
 
 159. The precipitation by chloride of calcium in an 
 ammoniacal solution on boiling, must not be regarded as 
 satisfactory proof of the presence of citric acid, since other 
 precipitates, particularly carbonate and sulphate of lime, 
 may, under some conditions, be obtained in a similar way. 
 
 Citric Acid, H 3 C 6 H 5 7 . Aq., forms colorless crystals, which 
 are readily dissolved by cold water. 
 
 When heated, the crystals fuse, carbonize, and emit irri- 
 tating inflammable vapors, very different from those evolved 
 by tartaric acid. Citric acid also leaves less charcoal than 
 tartaric. The charcoal burns away entirely if the acid is 
 pure. 
 
 Strong sulphuric acid heated Avith citric acid, evolves 
 much carbonic oxide gas, recognized by its burning with a 
 blue color on applying the mouth of the tube to a flame; 
 the mixture does not carbonize so readily as in the case of 
 tartaric acid. 
 
 Lime-water, added in large excess to a very small quantity 
 of solution of citric acid, does not produce a precipitate until 
 the mixture is boiled, when citrate of lime is deposited. On 
 cooling the solution, the precipitate will, at least partly, be 
 redissolved, since citrate of lime is more soluble in cold than 
 in hot water. 
 
140 CITRATES. 
 
 gives no precipitate ; but if potash be added, citrate of lime 
 is separated, which does not redissolve, like tartrate of lime, 
 on adding an excess of potash. 
 
 If a solution containing citric acid be mixed with potash 
 in excess and permanganate of potash, the latter will be 
 changed to the green manganate of potash, which will not 
 become brown on boiling (see tartaric acid). 
 
 The only citrates which are at all commonly met with 
 are the medicinal preparations citrate of iron, ammonio- 
 citrate of iron, citrate of iron and quinine, and citrate of 
 bismuth. 
 
 Citrates of lime and magnesia are imported from Sicily, 
 for the preparation of citric acid. 
 
 Citrate of Iron (ferric citrate) forms brilliant red or yellow 
 transparent scales, which taste sweet and astringent ; they 
 dissolve readily in water, forming a brown solution which 
 is precipitated by alcohol. The presence of citric aeid 
 prevents the precipitation of the ferric oxide on addition of 
 ammonia. 
 
 Ammonio- citrate of Iron is very similar to the citrate. 
 
 Citrate of Iron and Quinine also forms fine yellow scales, 
 in which, however, the bitter taste of quinine is perceptible. 
 Its solution yields a white precipitate of quinine on addition 
 of ammonia.* 
 
 Citrate of Bismuth is remarkable as being the only prepa- 
 ration of bismuth which can be dissolved in water without 
 decomposition. 
 
 By decomposing its solution with hydrosulphuric acid, the 
 bismuth may be precipitated as sulphide, and the filtered 
 solution, after evaporating to expel excess of hydrosulphuric 
 acid, may be tested for citric acid. 
 
 * The citrate of iron and quinine of the Pharmacopoeia contains 
 both ferrous and ferric oxides, so that it yields a dark blue color 
 with both ferrocyanide and ferricyanide of potassium. 
 
MALIC ACID. URIC ACID. 141 
 
 In the medicinal preparation, citrate of ammonia is usually 
 present. 
 
 Citrate of Lime, Ca 3 2C 6 H 5 O ? .4Aq., is a white powder 
 which turns red litmus blue. It dissolves sparingly in water, 
 but readily in hydrochloric acid. Ammonia precipitates the 
 solution only when boiled. When heated on platinum, it is 
 charred and decomposed, leaving a residue of carbonate of 
 lime, which effervesces with hydrochloric acid. 
 
 Citrate of Magnesia, Mg 3 2C 6 H.O 7 .14Aq., is a crystalline 
 granular salt, which is more soluble in water than the citrate 
 of lime. 
 
 The so-called "granulated effervescing citrate of magne- 
 sia" is often composed of a mixture of carbonate of soda with 
 citric, or occasionally tartaric, acid, which do not act upon 
 each other until water is added. 
 
 159. The chance of error from this cause is diminished 
 by mixing the original solution with carbonate of ammonia 
 until it is slightly alkaline, and evaporating at a gentle heat 
 till it is neutral. 
 
 160. This is a very satisfactory test for mallic acid, if the 
 solution be not too dilute and a large excess of lead acetate 
 be avoided. The malate of lead fuses into a white opaque 
 drop, which feels sticky when touched with a glass rod. 
 
 The crystallized mallic acid is somewhat deliquescent, has 
 an agreeable sour taste, and dissolves easily in water and 
 alcohol. When heated in a tube it fuses easily, and is after- 
 wards decomposed, with effervescence, evolving very pun- 
 gent vapors of fumaric and malaeic acids, which condense in 
 crystals upon the cool part of the tube.* 
 
 161. The presence of uric acid may be confirmed by the 
 test given in column 2 of Table N. 
 
 Uric Acid (or lithic acid], H 2 C 5 H 2 N 4 O 3 , itself is a white 
 or yellowish white crystalline powder, which dissolves very 
 
 * The malic acid of commerce sometimes contains a little oxalic 
 acid as an impurity. 
 
142 URATES OR LITIIATES. 
 
 sparingly, even in boiling water. It is also nearly insoluble 
 in hydrochloric acid, but dissolves on boiling in dilute nitric 
 acid, with brisk effervescence. It is also dissolved when 
 heated with a moderately strong solution of potash, and is 
 reprecipitated from this solution in a crystalline state, on 
 adding a slight excess of hydrochloric acid. 
 
 When heated, uric acid is carbonized, and emits vapors in 
 which the smell of ammonia and that of hydrocyanic acid 
 can be distinguished. 
 
 On platinum foil, uric acid, if pure, burns without residue. 
 
 Strong sulphuric acid does not blacken uric acid to any 
 great extent, even on heating, but dissolves it, in great 
 measure without change. On allowing the solution to cool, 
 and adding water, the greater part of the uric acid is pre- 
 cipitated. 
 
 The uric acid deposited from urine and occurring in uri- 
 nary calculi, is often colored yellow or brown by coloring 
 matters derived from the urine. 
 
 The urates of soda and ammonia are commonly met with 
 as deposits from urine, colored yellow, brown, or red,. by the 
 coloring matters of that excretion. They are both dissolved 
 when heated with water, and deposited again as the solution 
 cools. On adding hydrochloric acid to the warm solution, 
 crystalline uric acid is precipitated. 
 
 Urate of Ammonia, NH 4 HC 5 H 2 N 4 3 , of course, evolves 
 the smell of ammonia when boiled with potash. 
 
 Urate of Soda, NaHC 3 H 2 N 4 O 3 , when heated on platinum 
 foil, leaves a residue of carbonate of soda, recognized by its 
 solubility in water, giving a strongly alkaline solution, which 
 effervesces with hydrochloric acid. 
 
 161. In some cases it is difficult to identify the 
 organic acid in n, salt, until the mo.tnl hns been removed. 
 
EXAMPLES FOR PRACTICE. 143 
 
 Where the present metal belongs to either of the first three 
 classes (p. 18), the salt may be suspended or dissolved in 
 water, treated with an excess of hydrosulphuric acid, filtered 
 from the metallic sulphide, evaporated to a small bulk, and 
 tested by Table L. Salts of barium, strontium, calcium, 
 and magnesium may be boiled with carbonate of soda, fil- 
 tered, and the solution examined by Table M. 
 
 Some of the rarer organic acids are described at (174, 
 215, 218, 232). 
 
 162. Examples for Practice in Tables K, L, M, and 
 
 N The following substances may be analyzed for practice 
 
 (10):- 
 
 Tartaric acid 
 Bitartrate of potash 
 Tartar emetic 
 Acetate of lead 
 Uric acid 
 
 Tannic acid 
 Gallic acid 
 Benzoic acid 
 Citric acid 
 Acetate of soda. 
 
144 
 
 TABLE O. 
 
 s 
 
 "8 
 
 bo 
 
 
 
 ho 
 
 I 
 
 
 
 i! 
 
 d a 
 
 +J 
 
 8 
 
 CO 
 
 CO 
 
 p 
 
 cr 
 
 " 
 
 ^s 
 
 8 5 2 ! > 1 1 "8 
 
 5 a 
 
 S 'i 
 
 a 
 
 co <= ' - 
 
 "S la fc 
 
 i I s w 
 
 ^s 
 
 m 
 ol 
 
 HO 
 
 .2 s w 
 
 ; 2 
 
 S ^s 
 
 3-E 1 
 
 ed. 
 
 ssolv 
 See 
 umn 
 
 ve 
 in 
 
MORPHINE OK MORPHIA. 145 
 
 NOTES TO TABLE O. 
 
 164. Caffeine would give no precipitate with potash, and 
 would have escaped detection in the Table. 
 
 Caffeine (or Theine), C 8 H 10 N 4 O 2 .Aq., crystallizes in nee- 
 dles, which have a somewhat bitter taste, and dissolves 
 slightly in cold water, but entirely in boiling water ; the solu- 
 tion is neutral. It is also soluble in alcohol and ether. 
 Gently heated in a tube, caffeine fuses and sublimes in fine 
 needles. To identify it, dissolve it in very little strong hy- 
 drochloric acid, add a small crystal of chlorate of potash, and 
 evaporate just to dryness : the residue has a pink or red color, 
 and dissolves in ammonia to a fine purple liquid, which is 
 bleached by potash. 
 
 165. Morphine C 17 H 19 NO 3 .Aq., is a white crystalline 
 powder, which dissolves sparingly even in boiling water, 
 yielding a bitter solution, which is alkaline to test-papers. It 
 is also soluble in alcohol, but not in ether. 
 
 Strong nitric acid colors morphine orange-yellow, and 
 produces a similar color in solutions containing morphine. 
 
 Perchloride of iron (ferric chloride), free from excess of 
 acid, colors morphine inky blue. 
 
 Morphine, heated with strong sulphuric acid, and stirred 
 with a glass rod moistened with nitric acid, gives a rapid 
 play of colors, from dingy green to a rich brown. 
 
 The hydrochlorate (muriate), meconate, and acetate of 
 morphine are easily soluble in water. By mixing the aqueous 
 solution with carbonate of soda, and stirring briskly, the 
 morphine is precipitated, and may be collected upon a filter, 
 washed with cold water, and tested with perchloride of iron 
 or with nitric acid. 
 
 Meconate of Morphine is not crystallizable. 
 
146 STRYCHNINE. QUININE. 
 
 Acetate of Morphine, C ]7 H 1D NO 3 .C 2 H 4 O 2 , is crystalline, 
 but very deliquescent. 
 
 Hydrochlorate of Morphine is crystalline, C n H 1B NO a . 
 HCl.SAq., and not deliquescent. 
 
 The acids may be detected as in Tables H and L. 
 
 166. Brucine, C 23 H 26 N 2 O 4 .4Aq., is a white crystalline 
 powder, which may be dissolved by boiling water, yielding 
 a bitter solution. It also dissolves in alcohol, but not in 
 ether. 
 
 Strong nitric acid gives a bright red solution with brucine 
 which becomes yellow when heated. Protochloride of tin 
 (stannous chloride) changes the yellow color to violet. 
 
 If brucine be dissolved in a drop or two of diluted hydro- 
 chloric acid, and ammonia carefully added, an oily-looking 
 precipitate of brucine separates, which afterwards changes to 
 needle-like crystals. Excess of ammonia dissolves the oily 
 precipitate, and the solution deposits the needles after some 
 time. 
 
 167. Strychnine, C 21 H 22 N 2 O 2 , is met with either as a fine 
 white powder, or in hard prismatic crystals. It is scarcely 
 perceptibly dissolved, even by boiling water, but the solution 
 has an intensely bitter taste. It dissolves rather sparingly 
 in ordinary alcohol, and is soluble in absolute alcohol and in 
 ether. 
 
 If strychnine be dissolved, on a white surface of porcelain, 
 in strong sulphuric acid, and stirred with a few particles of 
 binoxide of lead (brown oxide), it gives a dark violet purple 
 color, quickly changing to red. The test with bichromate 
 of potash, given in Table O, is far more delicate, especially 
 if a very minute quantity of the bichromate be employed. 
 
 168. A solution of bromine in water may be substituted 
 for chlorine water in testing for quinine. Strong solutions 
 of quinine yield a green precipitate when tested with chlorine 
 (or bromine) and ammonia. Another excellent test for 
 quinine consists in adding to the acid solution a little chlorine 
 or bromine water, a drop or two of ferridcyanide of potassium, 
 
QUININE. NARCOTINE. 147 
 
 and, drop by drop, ammonia, which produces a fine red color 
 bleached by excess of ammonia. 
 
 Quinine, C^H^NjjO.^.SAq., is a white crystalline powder, 
 which is sparingly dissolved even by hot water, but dissolves 
 easily in alcohol. Ether does not dissolve it so easily. Its 
 solution is very bitter, and is alkaline to test-papers. 
 
 If quinine be dissolved in diluted sulphuric acid, and the 
 solution mixed with water and examined by daylight in a 
 test-tube, it will be found to exhibit a very pretty shade of 
 blue when in certain positions, though it appears quite color- 
 less when held directly between the eye and the light. 
 
 This fluorescence is very characteristic, and may be seen 
 even in dilute solutions. 
 
 Sulphate (or basic sulphate) of quinine, 2C 20 H 24 N 2 O 2 . 
 H a S0 4 .7Aq., forms very light silky needles, which are very 
 bitter, and will not dissolve, even in boiling water, unless a 
 little sulphuric or hydrochloric acid is added. 
 
 If sulphate of quinine is adulterated with salicine, C 13 H |8 O 7 , 
 it assumes a red color when moistened with strong sulphuric 
 acid. 
 
 To detect the presence of cinchonine, the sulphate is 
 shaken in a test-tube (or small stoppered bottle) with ammo 
 nia and ether, when pure sulphate of quinine entirely dis- 
 solves, the solution separating into two layers ; whilst any 
 cinchonine, being insoluble in ether, separates on the surface 
 of the lower (aqueous) layer. 
 
 169. Narcotine, C 22 H 23 NO 7 , is a white crystalline tasteless 
 substance, which is not alkaline to moistened test-papers. It 
 is insoluble in water, but dissolves in alcohol and ether, 
 yielding bitter solutions. 
 
 To identify it, dissolve it in a considerable quantity of 
 strong sulphuric acid, and stir the liquid with a glass rod 
 moistened with strong nitric acid, a dark red color is pro- 
 duced, which is bleached by more nitric acid. 
 
 If a few drops of solution of perchloride of iron be care- 
 fully added, from the end of a glass rod, to the solution of 
 
148 CIXCHONINE. 
 
 narcotine in strong sulphuric acid, a deep red liquid is pro- 
 duced, which becomes of a brighter color on cooling. 
 
 If narcotine be dissolved in dilute hydrochloric acid, and a 
 little solution of bromine be added, a yellow precipitate is 
 obtained, unless the solution is very dilute. On heating, 
 this precipitate is dissolved, and, by gradually adding solu- 
 tion of bromine and boiling, a fine rose color is produced, 
 even in very dilute solutions. Excess of bromine destroys 
 the color. 
 
 nO. CVracfomVze, ' C 20 H 24 N 2 O, is white, crystalline, and 
 slightly bitter. It is almost insoluble in water, but dissolves 
 in alcohol, yielding a bitter solution which has an alkaline 
 reaction. Ether does not dissolve it. Gently heated in a 
 tube, cinchonine fuses, emits a peculiar tarry ammoniacal 
 odor, and yields a sublimate of shining needles on the cooler 
 part of the tube. Moistened with dilute sulphuric acid, and 
 heated, it yields a fine red coloring matter. 
 
 If cinchonine be dissolved in as little dilute hydrochloric 
 acid as possible, the solution gives, with ferrocyanide of po- 
 tassium, a yellow precipitate, which dissolves when warmed 
 with a slight excess of the ferrocyanide, and is deposited in 
 yellow scales or needles on cooling. 
 
 /Sulphate of cinchonine^ 2C 20 H 24 N 2 O.H 2 SO 4 .2Aq., forms 
 white or brownish prismatic crystals which fuse when heated, 
 and yield a fine red coloring matter, as well as an aromatic 
 odor. 
 
 171. Examples for Practice in Table O. The following 
 substances may be examined for practice (10): 
 
 Hydrochlorate of morphine I Sulphate of quinine 
 Strychnine Cinchonine. 
 
INDIGO. PICRIC ACID. 149 
 
 EXERCISE X. (See (234) for Examples for Practice.) 
 
 172. IDENTIFICATION OF THE MORE COMMON ORGANIC 
 SUBSTANCES.* 
 
 1. SOLID ORGANIC SUBSTANCES. 
 A. Characterized by color. 
 
 173. Indigo, C 8 H 5 NO Dark blue. Insoluble in water, 
 
 alcohol, and ether. 
 
 Heated in a tube (17), yields violet vapors, smelling of 
 aniline and ammonia. 
 
 Strong sulphuric acid slowly dissolves indigo, when heated, 
 giving a blue solution, which is changed to brown-yellow by 
 nitric acid. 
 
 Shaken in a corked tube with sulphate of iron (ferrous 
 sulphate) and slaked lime, and allowed to settle, indigo dis- 
 solves to a yellow solution (reduced indigo, C 8 H 6 NO), which 
 becomes blue-green when decanted and acidulated with 
 hydrochloric acid. 
 
 174. Picric or Carbazotic Acid, HC 6 H 2 O3N0 2 Yellow 
 crystals. Very bitter. Stains the skin yellow. 
 
 Water dissolves it sparingly. Bright yellow solution. 
 
 Alcohol dissolves it easily. The solution gives a yellow 
 crystalline precipitate when stirred with a little potash. 
 
 Heated in a tube, fuses, and sometimes explodes slightly. 
 
 Strong sulphuric acid dissolves it, and deposits it un- 
 changed on addition of water. 
 
 Heated with solution of chloride of lime (bleaching pow- 
 der), it evolves a very pungent odor like oil of mustard, due 
 to chloropicrine, CC1 3 NO 2 . 
 
 175. Caramel, C 12 H 18 9 Dark-brown. Deliquescent. 
 Slightly bitter. 
 
 Very soluble in water, dark-brown solution. 
 Sparingly soluble in strong alcohol. 
 
 * Excluding: those which are treated of in Exercises 8 and 9. 
 
150 CARBOLIC ACID OK FHENOLE. 
 
 Heated in tube, carbonizes, and emits the odor of burnt 
 sugar. 
 
 Strong sulphuric acid carbonizes it. 
 
 B. Characterized by Odor. 
 
 176. Carbolic Acid (Phenic Acid) ; Phenole, C 6 H 6 O. 
 
 Moist needle-like crystals ; colorless or pale brown. Power- 
 ful odor of coal-tar. Very easily melted. Water dissolves 
 it sparingly. Easily soluble in potash. 
 
 Alcohol dissolves it readily. 
 
 Perchloride of iron (ferric chloride) gives a dark purple- 
 blue color with the aqueous solution of carbolic acid. 
 
 Dropped into strong nitric acid, carbolic acid is oxidized 
 with great violence, yielding a red solution ; if this be boiled 
 and allowed to cool, it deposits prismatic crystals of picric 
 acid which may be identified by (174). 
 
 YlQa. Hydrate of Chloral, C 2 HC1 3 O.H 2 O., white crystal- 
 line solid. Easily dissolved by water. 
 
 Remarkable pungent odor. 
 
 Easily melted and volatilized. 
 
 Heated with potash, yields an oily-looking layer of chloro- 
 form and a solution of formiate of potash, which may be 
 identified by neutralizing with dilute sulphuric acid, adding 
 nitrate of silver in excess, decanting the clear liquid from 
 any precipitated chloride of silver, and boiling it, adding 
 ammonia, drop by drop, when metallic silver is precipitated. 
 
 C. Without Characteristic Color or Odor. 
 Examine by Table P. 
 
TABLE P. 
 
 151 
 
 be 
 
 '8 
 
 1 
 
 ii 
 
 02 
 
 .S o 
 
 I'i 
 
 o Sf 
 2 O 
 
 o O 
 
 'S S 
 
 I SM 
 
 S 7^ w 
 
 I"l 
 
 X -^ h 
 
 w - H H 
 
 8 
 
 03 
 Q 
 
 m 
 
 
 M 
 
 1 
 
 
 
 03 
 
 d 
 
 'a 
 
 eg 
 H 
 
 o 
 
 'o 
 
 c/5 
 CM 
 
 rH 
 
 E 
 
 If it does not dissolve 
 
 examine by 
 (206). 
 
 
 
 3. 
 Boil the substance 
 
 with ALCOHOL. 
 
 If it dissolves, examine by 
 
 / s 
 
 CO 
 
 IH 
 
 1 
 
 'o 
 
 o 
 Pi 
 
 
 
 1 
 
 8 
 
 a 
 
 
 
 
 
 - S 
 
 
 03 
 
 H 
 
 'i 
 
 
 . 
 
 VI 
 
 ft 
 
 a^* 
 
 
 
 
 cS 
 
 1 
 ri 
 (N w 
 
 WATER. 
 
 3 
 
 x 
 
 03 
 
 8 
 
 > 
 
 fl 
 
 o 
 
 00 
 
 - dissolv< 
 
 CO 
 
 g 
 
 
 
 03 
 
 ^ 
 
 Q 
 
 "o 
 
 ^, 
 
 o 
 
 
 
 
 Q 
 
 ^ 
 
 
 c/I 
 
 
 
 o 
 
 
 
 ^ 
 
 '^ 
 
 ^' 
 
 03 
 
 
 I 
 
 a 
 
 
 
 1 
 
 
 5 
 
 
 
 
 
 
 
 
 03 
 
 16 
 
 03 
 
 -9 
 
 substance with 
 
 3 
 
 r- 
 
 
 1 
 
 for some time. 
 
 '3 
 
 j> 
 'o 
 
 .2 
 
 ly or in great measure, 
 
 mine the solution by 
 
 (178). 
 
 it does not dissolve, 
 
 ass on to column 2. 
 
 
 
 
 
 <tH 
 
 03 
 
 
 
 ft 
 
 02 
 
 
 
 
 
 FH 
 
 X 
 
 V-i 
 
 
 
 
 
 
 
 "3 
 
 03 
 
 
 
 
152 CANE AND GRAPE SUGARS. 
 
 NOTES TO TABLE P. 
 
 1*78. The commonest of these organic substances which 
 are dissolved to any considerable extent by being shaken 
 with cold water are * 
 
 Cane-sugar 
 
 Grape-sugar (or glucose) 
 Milk-sugar (or lactine) 
 
 Pyrogalline (or pyrogallic acid) 
 
 Salicine 
 
 Urea 
 
 Soluble albumen. 
 
 179. Cane-sugar, C la H 82 O u , identified. 
 
 Add to the solution a few drops of sulphate of copper, and, 
 drop by drop, potash. The blue precipitate first produced 
 redissolves in the excess of potash, to a blue liquid. Boil 
 for some minutes, suboxide of copper (cuprous oxide) is 
 deposited, first as a yellow hydrate, afterwards as the red 
 anhydrous oxide. 
 
 To another part of the solution, add excess of potash, and 
 boil, only a very light-brown color should be produced. 
 
 Heat a portion of the solid substance with strong sulphuric 
 acid, which should carbonize it almost immediately. 
 
 To a part of the aqueous solution, add a few drops of 
 dilute hydrochloric acid, and boil for a few minutes ; the 
 cane-sugar is thus converted into grape-sugar, which may be 
 identified by the following tests. 
 
 180. Grape-sugar, C 6 H 14 O 7 , identified. 
 
 Add to the solution an excess of potash, and boil. The 
 liquid should assume a rich brown color. 
 
 To another part of the solution, add a few drops of sulphate 
 of copper, and, drop by drop, potash. The blue precipitate 
 first produced redissolves in the excess of potash, to a blue 
 liquid, which deposits suboxide - of copper when heated (at 
 
 * See foot-note on pase 154. 
 
MILK-SUGAR. UREA. PYROGALLIX. 153 
 
 first yellow and afterwards red) more readily than in the case 
 of cane-sugar. 
 
 Heat a portion of the solid substance with strong sulphuric 
 acid : it should not carbonize so readily as cane-sugar. 
 
 Grape-sugar is much less sweet than cane-sugar.* 
 
 181. Milk-sugar, C 12 H 24 O 12 , identified. 
 
 Very much less sweet than either cane- or grape-sugar. 
 
 Feels gritty between the teeth. Almost insoluble in 
 ordinary alcohol, which dissolves cane- or grape-sugar on 
 heating. 
 
 Answers to the same tests as grape-sugar. 
 
 182. Urea, C 2 H 4 N 2 O 2 , identified. 
 
 Prismatic crystals. Resembles nitre in appearance and 
 taste. Very soluble in water and alcohol. 
 
 Heated in a tube, melts easily, and evolves much ammonia. 
 
 A pretty strong aqueous solution of urea, stirred with con- 
 centrated nitric acid in excess, and allowed to stand, deposits 
 scaly crystals of nitrate of urea. 
 
 If a strong solution of oxalic acid be substituted for nitric 
 acid, crystals of oxalate of urea are deposited. 
 
 If a solution of urea be mixed with a solution of mercuric 
 nitrate, t a white precipitate is produced. 
 
 On adding excess of silver nitrate to solution of urea, and 
 boiling down, in a test-tube, to a small bulk, a crystalline 
 precipitate of silver cyanate separates on cooling ; if this 
 precipitate be heated with dilute hydrochloric acid, it effer- 
 vesces, and evolves the pungent odor of cyanic acid ; on 
 adding potash, and boiling, the odor of ammonia is per- 
 ceived. 
 
 183. Pyrogallic acid or Pyrogallin, C 6 H 6 3 , identified. 
 White or slightly brown crystalline powder. Often 
 
 * Sugar of fruits (fructose or uncrystallizable sugar) answers to 
 the same taste as grape-sugar. 
 
 f Prepared by adding finely-powdered red oxide of mercury to 
 hot nitric acid as long as it is dissolved. 
 
154 SALICINE. ALBUMEN. STARCH. 
 
 collected into feathery flakes. Bitter. Very light. Dis- 
 solves easily in water, alcohol, and ether. 
 
 Potash renders it intensely brown, oxygen being absorbed 
 from the air. 
 
 Sulphate of iron (ferrous sulphate) colors solution of pyro- 
 gallic acid dark blue. 
 
 Perchloricle of iron (ferric chloride) gives a fine red color 
 with solution of pyrogallic acid. 
 
 184. Saticine, C 13 H 1S 7 , identified. 
 
 White crystalline powder. Bitter. More soluble in alco- 
 hol than in water. Insoluble in ether. Concentrated sul- 
 phuric acid converts it into a blood-red resinous mass. Its 
 aqueous solution, boiled for some time with hydrochloric 
 acid, yields a granular precipitate of saliretine. 
 
 185. Soluble albumen, C 72 H 112 N 18 SO 22 , identified. 
 Yellowish white shining scales. Tasteless. Assumes the 
 
 appearance of gum in cold water. Becomes opaque and 
 insoluble when boiled with water. The solution of albumen 
 in cold water is coagulated by boiling. 
 
 Dilute nitric acid precipitates it. 
 
 Perchloride of mercury (corrosive sublimate) causes a 
 white precipitate. 
 
 186. The commonest neutral organic substances which 
 are not dissolved by cold water,* but dissolve in boiling 
 water are 
 
 Gelatine 
 
 Gum 
 
 Dextrine or British gum 
 
 Starch 
 
 Oxalate and nitrate of urea. 
 
 187. Starch, C 6 H 10 O 5 , identified. 
 
 White. Tasteless. Forms a paste when boiled with a 
 
 * It must be remembered that this is not a very exacting dis- 
 tinction ; thus, at the ordinary temperature of the laboratory, dex- 
 trine and the oxalate and nitrate of urea dissolve pretty readily. 
 
DEXTRINE. GUM. GELATINE. 155 
 
 small quantity of water ; even with much water, yields a 
 turbid solution. 
 
 Boiled for some time with dilute hydrochloric acid, the 
 solution becomes thinner, and answers to the tests for grape- 
 sugar (180). 
 
 Solution of iodine in water, added to the (cold) solution of 
 starch, gives a fine blue color which disappears on boiling, 
 and returns as the liquid cools. Potash destroys the blue 
 color. 
 
 188. Dextrine, C 6 H 10 O 5 , identified. 
 
 Yellowish. Tasteless. Behaves like gum with cold water. 
 
 Boiled for some time with dilute hydrochloric acid, the 
 solution answers to the tests for grape-sugar (180). 
 
 Solution of iodine does not give the blue color. 
 
 Tribasic acetate of lead. (or ammoniacal acetate of lead) 
 does not precipitate the solution of dextrine, which is thereby 
 distinguished from ordinary gum. 
 
 Solution of tannic acid does not precipitate dextrine, which 
 thus differs from starch. 
 
 189. Gum, C 12 H 22 O U , identified. 
 
 Answers to the same tests as dextrine, but its solution is 
 precipitated by tribasic acetate (or ammonia calacetate) of 
 lead. Gum arabic contains lime, which may be detected by 
 oxalate of ammonia. 
 
 190. Gelatine C 41 H 6 .N 13 O 16 , identified. 
 
 Tasteless. Its solution in hot water sets to a jelly on 
 cooling. Perchloride of mercury (corrosive sublimate) pre- 
 cipitates it. Tannic acid precipitates it. 
 
 Evolves very offensive alkaline vapor when heated in the 
 dry state. 
 
 191. Soap may be identified by the directions given at 
 pp. 85 and 90. 
 
 192. Oxalate and nitrate of urea crystallize readily from 
 
156 UREA. STEARINE. 
 
 their aqueous solutions on cooling. The nitrate evolves a 
 remarkably pungent smell when heated in a small tube. 
 
 The oxalic and nitric acids may be detected by the tests 
 given in Table H. 
 
 The urea may be detected by mercuric nitrate (182), a 
 little potash being first added. 
 
 By adding carbonate of baryta to the aqueous solution, 
 evaporating to dryness on a water-bath (231), and treating 
 the residue with alcohol, the urea is dissolved, and may be 
 obtained, by evaporation, in crystals which can be identified 
 as in (182). 
 
 If a solution of nitrate or oxalate of urea be mixed with 
 excess of silver nitrate, filtered if necessary, sodium carbonate 
 added till a slight permanent precipitate appears, boiled, 
 filtered, and boiled down to a small bulk in a test-tube, the 
 liquid, on cooling, deposits silver cyanate which may be 
 identified as at (182). 
 
 193. The commonest of these organic substances which 
 are insoluble in water, but dissolve in hot alcohol, are 
 
 Stearine 
 Palmitic acid 
 Rosin 
 
 Stearic acid 
 Cholesterine 
 Naphthaline. 
 
 194. Stearine, C 57 H 110 O 6 , identified. 
 
 White. Crystalline. Fuses in water heated to 160 F. 
 (71 C.).* (See 194a.) 
 
 Dissolves in boiling alcohol, but not with extreme facility ; 
 deposited again on cooling. 
 
 Boiled with potash, forms at first a milky emulsion, and 
 gradually dissolves, yielding a solution of soap, p. 85. Heated 
 on platinum or porcelain, evolves the characteristic pungent 
 fumes of acroleine, and burns with a luminous flame. 
 
 * One modification of stearine fuses at 131 F. (55 C.) 
 
CHOLESTERINE. HOSIX. 157 
 
 194#. To ascertain the exact temperature at which a sub- 
 stance fuses, draw out a piece of glass tube (Fig. 15, p. 34) 
 to a fine tapering point, and introduce a fragment of the sub- 
 stance to be tested. Warm the tube gently so that the 
 melted substance may run into the point, where it will be- 
 come opaque on cooling. The tube is now plunged, together 
 with a thermometer, into a beaker (Fig. 55) of water slowly 
 heated over a lamp, and the temperature is noted at which 
 the point becomes transparent, in consequence of the fusion 
 of the substance. 
 
 195. Steric Acid, HC 18 H 35 O a , identified. 
 
 White. Crystalline. Fuses in water heated to 160 F. 
 (71 C.). (See 194a.) Dissolves very easily in boiling 
 alcohol ; the solution reddens litmus. Potash speedily dis- 
 solves it, yielding a solution of soap (191). When heated, 
 it does not evolve the pungent fumes of acroleine. It burns 
 with a luminous flame. 
 
 196. Palmitic Acid, HC, 6 H 31 O 2 , identified. 
 
 White. Crystalline. Fuses in water heated to 144 F. 
 (62 C.). (See 194.) In other respects resembles stearic 
 acid. 
 
 197. Cholesterine, C 26 H U O, identified. 
 
 Transparent tabular crystals. Infusible even in boiling 
 water. Dissolves easily in boiling alcohol, and crystallizes 
 out in rhombic plates. Not changed by boiling with potash. 
 
 Fuses easily when heated to 293 F., and passes off' in 
 vapor, which burns with a luminous flame. 
 
 Moistened with strong nitric acid, and evaporated to' dry- 
 ness, gives a yellow residue changed red by ammonia. 
 
 Moistened with strong hydrochloric acid, a little perchlo- 
 ride of iron added, and evaporated to dryness, assumes a 
 violet blue color. 
 
 198. Rosin identified. 
 
 Semi-transparent yellow or brown solid, smelling of tur- 
 
158 
 
 USE OF ETHER. 
 
 pentine. Dissolves in boiling alcohol ; the solution deposits 
 small crystals of (sylvic acid, HC^H^O^) as it cools. 
 
 Dissolves in boiling potash, and is reprecipitated in soft solid 
 flakes by hydrochloric acid. Fuses easily at (2GO or 270 
 F.) and burns with a very smoky flame. 
 
 199. Naphthaline, C 10 H 8 , identified. 
 
 Transparent flaky crystals smelling strongly of coal-gas. 
 Fuses in hot water at 174 F. (79 C.) (See 194a.) 
 Burns with a very smoky flame. Not changed by boiling 
 with potash. Heated in a dry test-tube, sublimes in crystals. 
 
 200. The inflammability of ether and the readiness witli 
 which it is converted into vapor, render it necessary to be 
 very careful in using it. 
 
 Never bring a bottle of ether within two or three feet of a 
 flame. Replace the stopper immediately. 
 
 Fid. 55. 
 
 In boiling a substance with ether ? 
 do not employ a flame, but place the 
 test-tube in some hot water, and 
 close the orifice lightly with the finger 
 in order to restrain the escape of 
 vapor (fig. 55). 
 
 201. The commonest organic sub- 
 stances which are insoluble in water, 
 and sparingly dissolved by alcohol, 
 but soluble in boiling ether, are 
 
 Palmitine 
 Spermaceti or cetine 
 
 Wax 
 
 Paraffine. 
 
 202. Palmitine, C 51 HggO 6 , identified. 
 
 White. Crystalline. Fuses in water heated to 145 F. 
 (63 C.)* (See 194a.) 
 
 Behaves in other respects like stearine (194), except as to 
 its solubility in alcohol. 
 
 One modification of palmatine fuses at 115O F. (46 C.). 
 
SPERMACETI. WAX. PARAFFINE. 159 
 
 203. Spermaceti, C 32 TI fil 2 , identified. 
 Characteristic pearly crystalline appearance. Fuses in 
 
 water heated to 120 F. (49 C.). (See 194.) Boiling 
 with potash does not saponify it. Does, not evolve the pung- 
 ent vapors of acroleine when heated, thus differing from 
 palmitine. 
 
 204. Wax identified. 
 
 White or yellow ; not distinctly crystalline. Fuses in water 
 heated to 145 or 150 F. (63 or 66 C.). (See 194a). 
 
 Boiled with alcohol, is partly dissolved. When the solu- 
 tion cools, cerotic acid, C 27 H 54 O 2 , crystallizes out, which fuses 
 in water heated to 174 F. (79 C.). The alcoholic solution 
 reddens litmus. When evaporated on a water bath, it leaves 
 ceroleine, a greasy substance of peculiar odor, fusible at 83 
 F. (28 C.). Wax is little affected by boiling with potash. 
 
 205. Paraffine identified. 
 
 White. Crystalline ; resembles spermaceti. Fuses in 
 water heated to 112 F. (44 C.).* (See 194a). Very 
 sparingly soluble in alcohol. Unaffected by boiling with 
 potash. May be distilled with little decomposition, which is 
 not the case with wax. 
 
 206. The commonest organic substances which are in- 
 soluble in boiling water, alcohol, and ether, and which can- 
 not be distinguished by their organized structure, f are 
 
 Albumen | Caseine. 
 
 Albumen and Caseine, in their coagulated or insoluble 
 states, so nearly resemble each other, that no satisfactory test 
 can be given by which they may be distinguished. 
 
 They are both white and opaque in the moist state, be- 
 coming horny, yellowish, and translucent when dried. 
 
 * Some specimens of paraffine fuse at 149 F. (65 C.). 
 
 f Such substances as fibrin, cellulose, lignine, hair, silk, wool, 
 horn, &c., would always be recognized without having recourse to 
 chemical tests. 
 
160 ALBUMEN. CASEINE. 
 
 Dried albumen and caseine, placed in water, slowly soften, 
 swell, and become \vhite and opaque. 
 
 Heated in a tube, they carbonize, swell up, and emit very 
 offensive vapors, which are strongly alkaline to reddened 
 litmus paper. 
 
 Strong nitric acid colors them bright orange, and gradually 
 dissolves them when heated. 
 
 Solution of nitrate of mercury, prepared by dissolving 2 
 parts of mercury in 4 parts of nitric acid (sp. gr. 1-40) im- 
 parts a bright red color to albumen and caseine (Millon's 
 test). 
 
 Potash dissolves albumen and caseine, when heated ; acetic 
 acid, gradually added to the solution, causes a flocculent 
 precipitate, which is redissolved by an excess of the acid. 
 
 If albumen or caseine be boiled with potash, and a few 
 drops of solution of acetate of lead, a dark precipitate of 
 sulphide of lead is produced. 
 
 Strong hydrochloric acid slowly dissolves albumen and 
 caseine with the aid of heat, yielding solutions which have a 
 violet color. 
 
LIQUID ORGANIC SUBSTANCES. TABLE 
 
 161 
 
 V 
 ll 
 
 x .3 
 
 rv] i. 
 
 ^ 
 II 
 
 O ^ 
 
 . * ^H 
 c> ^ 
 
 ?l 
 1 
 
 a 
 
 .0 CM 
 
 w 
 
 Q 
 
 03 
 
 Ilf 
 
 "- 1 
 
 
 I* 
 
 8 a? 
 
 .-y f- 
 
162 ALCOHOL. METHYLATED-SPIRIT. 
 
 NOTES TO TABLE Q. 
 
 208. The commonest liquid organic substances (not dis- 
 tinguishable by the preceding Tables) which have a distinct 
 color, and mix easily with water, are 
 
 Alcohol 
 
 Aldehyde 
 
 Aceton 
 
 Wood-spirit (methylic alcohol) 
 
 Nicotine 
 
 Butyric acid. 
 
 209. Alcohol, C 2 H 6 O, or Spirit of Wine (which is a 
 mixture of alcohol and water), may often be recognized at 
 once by its odor. 
 
 If not too much diluted, it inflames readily, and burns 
 with a pale flame. 
 
 If much water be present, it may be separated either by 
 carbonate of potash (226), or by distillation (227). 
 
 When alcohol, even in a diluted state, is mixed with enough 
 chromate or bichromate of potash to color it distinctly, a 
 little hydrochloric acid added, and heat applied, the red 
 color of the solution is changed to green, in consequence of 
 the reduction of the chromic acid to chromic oxide by the 
 deoxidizing effect of the alcohol, a part of which is converted 
 into aldehyde, distinguishable by its peculiar odor. 
 
 By heating alcohol with some slrong sulphuric acid, and 
 an acetate (either acetate of potash, soda, or lead), the very 
 agreeable odor of acetic ether is developed. 
 
 210. Methylated-spirit (a mixture of spirit of wine with 
 wood-spirit) may be distinguished from pure spirit of wine 
 by its odor, and by the brown red color which it assumes 
 when mixed with strong sulphuric acid. 
 
 211. Wood Naphtha, C H 4 O (pyroligneous ether, pyroxylic 
 spirit), is not commonly met with in commerce in a pure 
 state, in which form it bears much resemblance to ordinary 
 alcohol. The ordinary wood-naphtha has a yellowish color 
 and a peculiar nauseous odor. When mixed with water, 
 
WOOD-SPIRIT. ALDEHYDE. NICOTINE. 163 
 
 it becomes turbid, from the separation of certain oily im- 
 purities. 
 
 Wood-naphtha burns with a pale flame, resembling that of 
 alcohol. 
 
 Potash immediately imparts a brown color to wood- 
 naphtha, an effect not produced with alcohol until some time 
 has elapsed. 
 
 212. Acetone, C 3 H 6 O (wood-spirit), may be recognized 
 by its peculiar odor (which may be ascertained by heating 
 solid acetate of lead in a small tube). It differs also from 
 alcohol and wood-naphtha by burning with a very luminous 
 flame. 
 
 213. Aldehyde, C 2 H 4 O, has a very peculiar acrid apple- 
 like smell which affects the eyes. When exposed to the air 
 it passes off in vapor much more readily than alcohol, wood- 
 naphtha, or acetone, first becoming acid from absorption of 
 oxygen. 
 
 If aldehyde be added to nitrate of silver mixed with a 
 very little ammonia, the metal is reduced on the application 
 of heat, and forms a mirror-like coating upon the side of the 
 tube. Potash imparts a brown color to aldehyde. Alde- 
 hyde is very inflammable, and burns with a pale flame. 
 
 214. Nicotine, C 10 H 14 N 2 , is an oily liquid, tinged brown 
 by exposure to air, and having a powerful odor of tobacco. 
 
 Its aqueous solution is strongly alkaline to test-papers. 
 When the aqueous solution is acidulated with hydrochloric 
 acid, mixed with bichloride of platinum, and allowed to stand, 
 it deposits a precipitate composed of very distinct prismatic 
 crystals. 
 
 Nicotine is inflammable, and burns with a smoky flame. 
 
 215. Butyric Acid HC 4 H 7 O 2 , is a colorless liquid, having 
 a most powerful smell of rancid butter. It is somewhat 
 lighter than water, in which it dissolves when shaken. If 
 strong hydrochloric acid be added to the aqueous solution, 
 the butyric acid separates again as an oil upon the surface. 
 
164 BUTYRIC ACID. ANILINE OR PHENYLAMINE. 
 
 When butyric acid is shaken with alcohol and oil of vitriol, 
 butyric ether is formed, which is recognized by its odor of 
 pine-apple. 
 
 216. The commonest liquid organic substances (not dis- 
 tinguishable by the preceding Tables) which have a distinct 
 odor, do not mix easily with water, but are miscible with 
 potash, are 
 
 Carbolic acid (in its liquid form) | Valerianic acid. 
 
 21*7. Liquid Carbolic Acid is usually met with as a 
 brownish or brown liquid, having a powerful smell of tar. 
 When poured into water, it sinks to the bottom. 
 
 It may be further examined as at (176). 
 
 218. Valerianic Acid, HC 5 H 9 O 2 , is a colorless oily liquid, 
 which floats upon water, and has a powerful odor resembling 
 that of valerian root. 
 
 219. Aniline C 6 H 7 N, is usually met with as a yellowish 
 or brown oily liquid, having a strong smell recalling that of 
 ammonia. It sinks in water. 
 
 Solution of chloride of lime added in excess to a drop of 
 aniline shaken with water produces an intense purple color, 
 If toluidine be present, as is generally the case with commer- 
 cial aniline, the purple color passes into brown ; but if the 
 mixture be shaken with ether, the latter will rise to the 
 surface, carrying a red-brown coloring matter with it, and 
 leaving the solution of a fine blue color. Deal is stained 
 yellow by aniline. 
 
 Oxalic acid combines with aniline to form a sparingly 
 soluble oxalate. 
 
 Corrosive sublimate (mercuric chloride) in the solid form, 
 heated with aniline, converts it into a dark purple mass 
 which yields a purple-red solution in alcohol. 
 
ETHER. CHLOROFORM. 165 
 
 220. The commonest liquid organic substances (not dis- 
 tinguishable by the preceding Table) which have a distinct 
 odor and do not mix easily with water, potash, or hydro- 
 chloric acid, are 
 
 Ether 
 
 Chloroform 
 
 Benzole 
 
 Oil of bitter almonds 
 Nitrobenzole 
 Bisulphide of carbon. 
 
 221. Ether, C 4 H 10 O, may be identified almost with cer- 
 tainty by its odor. It is colorless, very easily inflammable, 
 and burns with a bright flame. Ether very easily passes off 
 in vapor when exposed to the air, so that when the mouth 
 of a test-tube which contains ether is applied to a light the 
 vapor takes fire, and burns at the mouth of the tube if the 
 latter be slightly inclined. 
 
 Ether boils at a temperature (94.8 F., 35 C.) which 
 feels scarcely warm to the hand. 
 
 Oil or fat of any kind dissolves very easily in ether. 
 
 222. Chloroform, CHC1 3 , is a colorless, very fragrant 
 liquid, which sinks in water (sp. gr/1.5). 
 
 It easily escapes in vapor when exposed to air, and boils 
 at 142 F. (61 C.). 
 
 Chloroform dissolves India-rubber with great facility. 
 
 When chloroform is gently heated with a solution of 
 hydrate of potash in alcohol it yields chloride of potassium 
 and formiate of potash. The former may be recognized by 
 the white precipitate with nitrate of silver, insoluble in nitric 
 acid, and the latter by neutralizing the alkaline liquid with 
 dilute sulphuric acid, adding an excess of nitrate of silver, 
 decanting the liquid from the precipitate, and gently heat- 
 ing it, when metallic silver will be separated as a dark 
 precipitate, either at once or on adding a drop or two of 
 ammonia. 
 
 The tests for ascertaining the purity of the chloroform 
 employed in surgical operations, are the following: 
 
166 BITTER ALMOND OIL. NITROBENZOLE. BENZOLE. 
 
 It should be quite free from any odor of chlorine. 
 
 When shaken with water, the solution should not redden 
 blue litmus paper, or produce any turbidity with nitrate of 
 silver. 
 
 When shaken with oil of vitriol, the mixture should re- 
 main colorless. 
 
 On evaporating a little chloroform on the hand it should 
 not leave any unpleasant odor. 
 
 233. Oil of Bitter Almonds, C 7 H 6 O 2 , has a very charac- 
 teristic smell, a yellowish color, and sinks in water. 
 
 When heated with solid hydrate of potash it yields ben- 
 zoate of potash. If the cool mass be dissolved in water, and 
 hydrochloric acid added to the solution, benzoic acid is 
 precipitated (154). 
 
 As sold in the shops, the oil of bitter almonds is often 
 dissolved in spirit of wine, from which it is separated on 
 adding water. 
 
 224. Nitrobenzole, C 6 H 5 NO 2 , or Essence of Mirlane, 
 much resembles oil of bitter almonds in appearance and 
 odor, but may be easily distinguished from it by converting 
 it into analyne. 
 
 For this purpose the nitrobenzole is dissolved in alcohol, 
 some hydrochloric acid added, and a fragment of granulated 
 zinc. When the evolution of hydrogen has nearly ceased, 
 the liquid is mixed with excess of potash and shaken with 
 ether, which dissolves the aniline. When the ether has risen 
 to the surface, it is poured off into a small dish and allowed 
 to evaporate spontaneously, when the aniline will remain, 
 and may be identified as at (219). 
 
 225. Benzole, C 6 H 6 , or Benzine, or Benzene, is a color- 
 less liquid which smells strongly of coal-gas. 
 
 It floats on water, is very inflammable, and burns with a 
 luminous smoky flame. 
 
SEPARATION OF ALCOHOL FROM WATER. 167 
 
 When added, drop by drop, to the strongest nitric acid, 
 benzole is dissolved, with evolution of much heat and red 
 fume, to a red liquid, and if this be poured into a large 
 volume of water, a heavy oil is separated, which is nitroben- 
 zole, and may be identified as described above (224). 
 
 Bisulphide of Carbon, CS 2 , is a colorless or yellowish 
 liquid, which sinks in water and has a most offensive smell.* 
 It is extremely inflammable, and burns with a blue flame, 
 emitting a powerful odor of sulphurous acid. If a few drops 
 be placed in a watch-glass, and blown upon, it will evaporate 
 very rapidly, condensing the moisture upon the glass into 
 white hoar-frost, and freezing a part of the bisulphide to a 
 white crystalline mass. 
 
 226. Removal of water from alcohol by carbonate of 
 potash. Pour the liquid into a large test-tube, or a draught- 
 bottle furnished with a good cork, so that the tube or bottle 
 may be about half-filled. Introduce dried powdered carbonate 
 of potash, in small portions, shaking well after each addition, 
 as long as it dissolves in the liquid. If alcohol be present, 
 it will form a separate layer upon the surface of the solu- 
 tion of carbonate of potash in water. Pour off this layer 
 carefully into another tube, and dip a glass-rod in it to test 
 its inflammability. It m..y then be examined by other tests 
 for alcohol. 
 
 227. Separation of alcohol and water by distillation 
 
 To separate alcohol from water by distillation, the mixture 
 must be maintained for some time at a temperature below 
 212 F. (100 C.), when the alcohol wall rise in vapor much 
 more readily than the water, and if the first portions of vapor 
 be condensed and collected in another vessel, they will be 
 found to contain the chief part of the alcohol. 
 
 * Purified bisulphide of carbon has not an offensive odor. 
 
168 DISTILLATION. 
 
 DISTILLATION The best form of apparatus for distillation 
 is that represented in fig. 57, where a represents a Retort, 
 through the tubulus (&) of which a thermometer* (c) is fixed 
 by means of a perforated cork (228) so that the bulb of the 
 thermometer nearly touches the bottom of the retort. The 
 neck of the retort is thrust into the inner tube (e?) of a Liebig*s 
 condenser, through the outer tube (e) of which a constant 
 flow of water is maintained by means of the pipes (/) (which 
 comes from the tap) and (g) (which runs into the sink). 
 These pipes are vulcanized India-rubber, and (y) is slipped 
 on to a piece of gas-pipe or glass tube (h) bent into a hook, 
 so as to hang upon the funnel (i). The joint (&), where the 
 retort neck is fitted into the condensing tube, is secured by a 
 
 FIG. 56. Fia. 57. 
 
 Distillation. 
 
 tight bandage made by warming a piece of sheet india- 
 rubber about four inches long and one broad, securing 
 one end of it with the thumb over the joint, and 
 stretching it very considerably whilst binding it round 
 the tubes (fig. 58). The condensed liquid drops into 
 the bottle (m), which may be changed when necessary 
 without disturbing the apparatus. 
 
 Thermo- 
 meter. 
 
 flip t.lip.rninTnetttr adapted for this Duroose. 
 
DISTILLATION. 
 
 FIG. 58. 
 
 1G9 
 
 Heat is gradually applied to the FIG. 59. 
 
 retort, either by a rose gas burner 
 (fig. 59), or a plain ring burner 
 (fig. 60), or an Argand burner with 
 a chimney (fig. 32, p. 94). 
 
 Since alcohol boils at 173 F. 
 (78-3 C.), a rough estimate of the 
 proportion of alcohol present may 
 be formed from the quantity of 
 liquid which distils over at a few 
 degrees above that temperature, and 
 the distillation may be stopped 
 
 when the thermometer approaches 212 F. (100 C.) and the 
 taste and smell of the liquid distilling over (distillate} indi- 
 cate the presence of very little alcohol. 
 
 Where such an apparatus as that just described is not to 
 be obtained, some simpler contrivance must be substituted 
 for it. 
 
 Hose Burner. 
 
170 DISTILLATION. 
 
 A plain retort (, fig. 60) with a long neck may be em- 
 ployed, and any common bottle (b) will serve for a receiver. 
 
 Distillation. 
 
 To promote condensation, a long strip of filter-paper (c) may 
 be wetted and wrapped smoothly round the neck, a 
 string of wet tow (d) being passed twice round the 
 neck at the lower edge of the paper, and twisted 
 tightly into a tail to carry off the water, which may 
 either be gently poured from time to time upon the 
 upper part of the paper, or allowed to trickle slowly 
 from a funnel (e), the neck of which is partly stopped 
 with tow. A tube funnel (fig. 61) is employed for 
 introducing the liquid into the retort without soiling 
 the neck. 
 
 A flask with a bent tube (229), tightly fitted into 
 it with a perforated cork (228), may be employed 
 Tube, instead of a retort. One limb of this tube may be 20 
 
 funnel. * 
 
 or 30 inches long, to insure condensation, or it may 
 be adapted, either by a perforated cork or a caoutchouc 
 bandage, to a wider tube of considerable length (fig. 62). 
 A convenient support for this tube is made by fixing a per- 
 
TO PERFORATE CORKS. 
 
 171 
 
 forated bung into the ring of a retort-stand turned round 
 into the required position. 
 
 FIG. 
 
 228. To perforate corks Smooth cylindrical holes are 
 
 made in corks with rat' s-tail files (fig. 63), beginning with a 
 
 FIG. 63. 
 
 FIG. 64. 
 
 Rat's-tail file. 
 
 small size, and employing the larger files as may be neces- 
 sary. Corks should always be kept on the points of the files 
 when not in use, as the steel is very brittle. 
 
 A set of brass cork borers of 
 various sizes (fig. 65) will save 
 much time. They are made to slip 
 into each other, and are provided 
 with a steel rod (fig. 64) which 
 serves as a handle and for thrusting out the cylinders of cork 
 punched by the borers. A cork-borer is selected of some- 
 what less diameter than 
 the tube for which the 
 hole is to be bored, 
 and the rod is thrust 
 through the holes in the 
 head of the borer. The 
 cork is held firmly 
 against the wall or the 
 
 Fia. 65. 
 Set of cork-borers. 
 
 FIG. 66. 
 
172 
 
 BENDING GLASS TUBES. 
 
 and the borer worked straight into it, like a gimlet, until it is 
 about half way through the cork. The borer being with- 
 drawn, and cleared, if necessary, with the rod, the cork is 
 reversed, and bored in the opposite direction, so that the two 
 holes may meet in the centre, and form a perfectly smooth 
 cylindrical passage, which is very carefully enlarged with 
 a rat's-tail file until it is just large enough to receive 
 the tube, which should pass through it with considerable 
 friction. 
 
 In fitting corks air-tight they should be carefully selected 
 as free from flaws as possible, especially at the ends. The 
 cork should be somewhat too large to enter the mouth of the 
 vessel until it has been softened by rolling it heavily on the 
 table with the palm of the hand, or, in the case of large corks, 
 under the sole of the boot. Corks are always to be preferred 
 to bungs or shives. 
 
 Vulcanized India-rubber stoppers are often substituted for 
 corks, and are decidedly preferable in a great many cases. 
 They may be perforated with the cork-borers described 
 above, which should be dipped in spirit of wine. 
 
 229. To bend glass tubes Small tubing may be bent 
 
 either in the flame of 
 a spirit-lamp, or in 
 the upper part of a 
 somewhat flaring gas- 
 flame (fig. 67). The 
 tube should be slowly 
 rotated, and moved to 
 and fro in the flame 
 until soft enough to 
 be bent, which should 
 be effected by a gen- 
 tle equal pressure 
 with both hands, 
 care being taken so 
 to regulate the soft- 
 
 FIG. 67. 
 
 Bending glass tube. 
 
SPIRIT BLOWPIPE. 
 
 173 
 
 Fia. 68 
 
 en ing of the glass as to 
 obtain a nice curve (fig- 
 68) instead of a sharp 
 angle (fig. 69). Any soot 
 which has been deposit- 
 ed from the flame may 
 be wiped off with paper 
 when the tube is cool. 
 
 Large tubing is more 
 difficult to bend, and it 
 is often necessary to em- 
 ploy a blowpipe flame. The bend must be annealed by 
 withdrawing it very gradually from the heat. 
 
 The gas blowpipe represented in fig. 70 is very convenient 
 for such purposes, especially if connected with a double-action 
 bellows worked by the foot. 
 
 FIG. 69. 
 
 Fia. 70. 
 
 Fia. 71. 
 
 Gas blowpipe. 
 
 Spirit blowpipe. 
 
 Where gas is not to be had, a spirit blowpipe-lamp is some- 
 times used. That represented in fig. 71 answers the purpose 
 very well. A small quantity of spirit (either methylated 
 spirit of wine or wood- naphtha) burnt inside the vessel a 
 vaporizes the spirit in the space b between the walls ; the 
 vapor issuing from the jet c, burns with a powerful flame. 
 These lamps are not free from danger in consequence of a 
 particle of cork getting into the spirit and obstructing the 
 
174 GLYCERINE. LACTIC ACID. OLEIC ACID. 
 
 jet, when the operator should at once place the cover on the 
 lamp, and thus extinguish the flame. 
 
 230. If the liquid has no powerful or characteristic odor 
 it may be 
 
 Glycerine t Lactic acid 
 
 Oleine Oleic acid. 
 
 231. Glycerine, C 3 H 8 O 3 , is a syrupy liquid which has an 
 intensely sweet taste and mixes readily with water. 
 
 Flo 72 Heated sharply on a knife-blade or a 
 
 piece of platinum foil, it burns with a 
 luminous flame. No residue is left. 
 
 When heated with strong sulphuric 
 acid, it blackens and evolves verv 
 pungent vapors of acroleine, which 
 strongly affect the eyes. 
 
 The same substance is produced by 
 heating a little bisulplmte of potash 
 moistened with glycerine. 
 Placed in an evaporating dish heated upon a water-bath 
 (fig. 72), glycerine suffers no perceptible diminution or 
 change, whilst ordinary syrup, which it much resembles, 
 gradually deposits crystals of sugar at the edge of the liquid. 
 
 232. Lactic acid, HC 3 H.O 3 , is a syrupy liquid which has 
 a strong acid taste and readily mixes with water. 
 
 It is not changed by heating on the- water-bath (fig. 72). 
 If it be diluted with water, and boiled with metallic zinc, 
 the solution, on cooling, deposits crystalline crusts of lactate 
 of zinc. 
 
 When lactic acid is heated in a retort, several products are 
 distilled over, and among them a crystalline solid known as 
 lactide, C 3 H 4 O 2 ,-which is soluble in hot strong alcohol, and is 
 deposited in transparent flat prismatic crystals on cooling. 
 
 233. Oleine, C 57 H 104 O 6 , and oleic acid, HC 13 H 33 O 2 , are 
 colorless or yellow oils which do not mix with water, but 
 float upon its surface. 
 
EXAMPLES FOR PRACTICE. 
 
 175 
 
 Alcohol dissolves oleic acid more readily than oleine. 
 
 Ether dissolves them botli very readily. 
 
 Solution of potash dissolves oleic acid more easily than it 
 dissolves oleine. 
 
 Oleine when strongly heated evolves the odor of aeroleine, 
 which is not produced when oleic acid is heated. 
 
 If a test-tube containing oleic acid is placed in melting ice 
 the oleic acid solidifies to a mass of needle-like crystals, but 
 oleine remains liquid. When oleic acid has been kept for 
 some time in contact with air it acquires a brown color and 
 an acid reaction. It does not then solidify at the melting- 
 point of ice. 
 
 234. Examples for Practice in Exercise X. Since it 
 is only by a careful study of individual organic substances 
 that the analyst can learn to identify them with certainty, 
 the student is recommended to examine as many of the sub- 
 stances mentioned in this Exercise as he is able to procure. 
 A list of them is subjoined. 
 
 Acetone 
 
 Ether 
 
 Palmitic acid 
 
 Albumen (white of 
 
 Gelatine 
 
 Palmitine 
 
 egg) 
 
 Glycerine 
 
 Paraffine 
 
 Alcohol 
 
 Grape-sugar 
 
 Picric or carbazotic 
 
 Aldehyde 
 
 Gum arable 
 
 acid 
 
 Aniline 
 
 Indigo 
 
 Pyrogallic acid 
 
 Benzole 
 
 Lactic acid 
 
 Rosin 
 
 Butyric acid 
 
 Methylated alcohol 
 
 Salicine 
 
 Cane-sugar 
 
 Milk-sugar 
 
 Soap 
 
 Caramel 
 
 Naphthaline 
 
 Spermaceti 
 
 Carbolic acid 
 
 Nicotine 
 
 Starch 
 
 Caseine (curd of 
 
 Nitrate of urea 
 
 Stearic acid 
 
 milk) 
 
 Nitrobenzole 
 
 Stearine 
 
 Chloral hydrate 
 
 Oil of bitter almonds 
 
 Urea 
 
 Chloroform 
 
 Oleic acid 
 
 Valerianic acid 
 
 Cholesterine 
 
 Oleine 
 
 Wax 
 
 Dextrine 
 
 Oxalate of urea 
 
 Wood-naphtha. 
 
176 
 
 ORGANIC SUBSTANCES EXAMINED. 
 
 EXERCISE XI. 
 
 235. EXAMINATION OF A SOLID ORGANIC SUBSTANCE 
 ABOUT WHICH NOTHING IS KNOWN BUT THAT IT IS A SlN- 
 GLE SUBSTANCE AND NOT A MIXTURE. 
 
 The analyst is recommended to mark off each substance 
 from the subjoined list as it is excluded by his experiments, 
 and in this way to reduce the number of possible substances 
 within very narrow limits : 
 
 Acetates 
 
 Albumen 
 
 Aniline salts 
 
 Benzoates 
 
 Ben zoic acid 
 
 Brucine 
 
 Caffeine 
 
 Cane-sugar 
 
 Caramel 
 
 Carbolic acid 
 
 Caseine 
 
 Cholesterine 
 
 Cinchoniiie 
 
 ' ' sulphate 
 Citrates 
 Citric acid 
 Cyanides 
 Dextrine 
 Ferridcyanides 
 Ferrocyanides 
 Gallic acid 
 Gelatine 
 Grape-sugar 
 Gum 
 
 Hipp uric acid 
 Indigo 
 Malic acid 
 Meconic acid 
 Milk-sugar 
 Morphine 
 
 " acetate 
 
 " hydrochlorate 
 
 " meconate 
 Naphthaline 
 
 Narcotine 
 Nitroprussides 
 Oxalates 
 Oxalic acid 
 Palmitic acid 
 Palmitine 
 Paraffine 
 Picric acid 
 Prussian blue 
 Pyrogailic acid 
 Quinine 
 
 " and iron, citrate 
 " sulphate 
 Rosin 
 Salicine 
 Soap 
 
 Spermaceti 
 Starch 
 Stearic acid 
 Stearine 
 Strychnine 
 Succinic acid 
 Sugar 
 
 Sulphocyanides 
 Tannic acid 
 Tartaric acid 
 Tartrates 
 Urates 
 Urea 
 
 " nitrate 
 
 " oxalate 
 Uric acid 
 Wax. 
 
ORGANIC SUBSTANCES EXAMINED, 
 
 177 
 
 A. Heat the substance gradually in a small glass tube (17). 
 (a) It fuses easily, becoming perfectly liquid. 
 
 Albumen 
 Caseine 
 
 EXCLUDES. 
 
 Dextrine 
 Starch 
 
 Urates 
 Uric acid. 
 
 (b) It passes off in vapor 
 
 (with or without previous fusion) 
 
 and leaves no black (carbonaceous') residue. 
 
 EXCLUDES 
 
 Albumen 
 
 Caramel 
 
 Caseine 
 
 Cinchonine and its salts 
 
 Citric acid and citrates 
 
 Dextrine 
 
 Gallic acid 
 
 Gelatine 
 
 Gum 
 
 Morphine and its salts 
 
 Quinine and its salts 
 
 Salicine 
 
 Starch 
 
 Strychnine and its salts 
 
 Sugar 
 
 Tannic acid 
 
 Tartaric acid and tartrates 
 
 Uric acid and urates. 
 
 (c) It passes off in vapor, leaving no residue whatever. 
 
 EXCLUDES 
 
 all the substances in the above list, and, in addition, 
 all metals except mercury, arsenic, and ammonium, 
 (c?) It emits vapors which have the odor of Ammonia, 
 and change red litmus paper to blue. 
 
 PROBABLE PRESENCE OF 
 
 Ammonia, combined with an 
 
 organic acid 
 Urea 
 Uric acid 
 A ferrocyanide 
 A cyanide 
 A sulphocyanide 
 A ferridcyanide 
 
 Gelatine 
 
 Albumen 
 
 Caseine 
 
 Morphine 
 
 Quinine 
 
 Cinchonine 
 
 Stry ch nine 
 
 Aniline. 
 
 The analyst should mark off such of these as have been 
 excluded by the previous experiments. 
 
178 
 
 ORGANIC SUBSTANCES EXAMINED. 
 
 If the evolution of ammonia is abundant and unat- 
 tended by any carbonization, either urea or one 
 of its salts is probably present (182, 192). 
 
 B. Heat the substance on a piece of porcelain, and continue 
 
 the heat until no further change is perceptible, direct- 
 ing the outer blowpipe-flame upon it if necessary, to 
 burn off the carbon. 
 (a) No residue is left. 
 
 EXCLUDES 
 
 all metals except mercury, arsenic, and ammonium, 
 (i) A residue is left, which is strongly alkaline to 
 moistened red litmus paper. 
 
 PROBABLE PRESENCE OF 
 
 an Organic Acid, in combination with Potash, Soda, 
 Baryta, Strontia, or Lime. 
 (See Table K.) 
 
 C. Shake a little of the substance with cold water,* in a 
 test-tube. 
 
 () It dissolves easily. 
 
 EXCLUDES 
 
 Albumen 
 
 Palmitine 
 
 Benzoic acid (free) 
 Brucine 
 Caffeine 
 
 Paraffine 
 Quinine (free) 
 Rosin 
 
 Caseine 
 
 Salicine 
 
 Cholesterine 
 Cinchonine (free) 
 Dextrine (?) 
 Gallic acid (free) 
 Gelatine 
 Gum 
 
 Spermaceti 
 Starch 
 Stearic acid (free) 
 Stearine 
 Strychnine (free) 
 Urates 
 
 Hippuric acid (free) 
 Morphine (free) 
 Karoo-tine 
 
 Urea nitrate (?) 
 " oxalate (?) 
 Uric acid. 
 
 Palmitic acid (free) 
 
 
 * See foot-note on page 154. 
 
ORGANIC SUBSTANCES EXAMINED. 179 
 
 6) It does not dissolve. 
 
 Boil it with the water ; should it dissolve, this 
 
 Albumen 
 
 Casein e 
 
 Palmitic acid (free) 
 
 EXCLUDES 
 
 Palmitine 
 Paraffine 
 
 Spermaceti 
 
 Stearic acid (free) 
 
 Stearine 
 
 Wax. 
 
 D. Very cautiously taste a particle of the substance. 
 
 () Its taste is acid. 
 
 Examine for an organic acid by Table K, and for an 
 
 inorganic acid by Table G. 
 (b) Its taste is bitter ; pass on to F. 
 
 E. If the substance does not dissolve readily in water, but 
 
 dissolves on adding a little potash, and is precipitated 
 by the addition of hydrochloric acid 
 
 Examine especially for 
 
 Benzoic acid (154) | Hippuric acid (156) 
 
 Uric acid (161) 
 
 F. Dissolve a little of the substance in water, or in a little 
 
 dilute hydrochloric acid, and test with a solution of 
 iodine in iodide of potassium. 
 
 If a brown precipitate is obtained, examine for an alka- 
 loid by Table O. 
 
 If a yellow precipitate is produced, examine for acetate 
 of lead (p. 29). 
 
 If a blue precepitate is produced, examine for starch 
 (187). 
 
 If the iodine-solution is bleached, examine for a cyanide 
 (99). 
 
180 LIQUID ORGANIC SUBSTANCES EXAMINED. 
 
 EXERCISE XII. 
 236. EXAMINATION OF A LIQUID ORGANIC SUBSTANCE 
 
 ABOUT WHICH NOTHING IS KNOWN, BUT THAT IT IS A 
 
 SINGLE SUBSTANCE AND NOT A MIXTURE. 
 
 A. Ascertain whether it has any odor or taste characteristic 
 of 
 
 Acetic acid (149) 
 Acetone (212) 
 Alcohol (209) 
 Aldehyde (213) 
 Aniline (219) 
 Benzole (225) 
 
 Bitter almond oil (223) j 
 Butyric acid (215) 
 Carbolic acid (217) 
 Chloroform (222) 
 Ether (221) 
 
 Glycerine (231) 
 Nicotine (214) 
 Nitrobenzole (224) 
 Sugar (179-181) 
 Valerianic acid (218) 
 
 Fomic acid (150) | Wood-naphtha (2J1). 
 
 B. Evaporate a little of the liquid in a porcelain dish, care- 
 
 fully observing any odor which may be developed, and 
 stopping the evaporation as soon as the liquid has dis- 
 appeared.* 
 
 (a) If no residue is left 
 
 The liquid probably contains one of the above-men- 
 tioned substances recognizable by their odor, or 
 possibly glycerine (231), or lactic acid (232). 
 
 (b) If an oily inflammable residue is left 
 
 Examine especially for 
 Oleine (233) | Oleic acid (233). 
 
 (c) If a solid residue is left 
 
 Evaporate a large quantity of the liquid and examine 
 the residue according to (235). 
 
 C. Whilst the evaporation is proceeding, the analyst should 
 
 examine another portion of the liquid by Tables L, O, Q. 
 
 * Should time permit it, it is well to evaporate over a steam-bath. 
 
UNKNOWN LIQUIDS EXAMINED. 181 
 
 EXERCISE XIII. 
 
 237. EXAMINATION OF A SOLID SUBSTANCE OF WHICH 
 NOTHING IS KNOWN, BUT THAT IT IS A SlNGLE SUBSTANCE, 
 
 AND NOT A MIXTURE. 
 
 A. Heat a little of the substance on a piece of porcelain, and 
 
 observe whether there is any carbonization or peculiar 
 odor to indicate the presence of organic matter.* 
 
 B. Heat another portion of the substance with strong sul- 
 
 phuric acid, and observe whether any carbonization 
 indicative of organic matter takes place. 
 
 (a) If organic matter is detected, the substance must 
 
 be examined, according to (235). 
 
 (b) If no organic matter is detected, the substance may 
 
 be examined, according to Tables A to I, or by 
 the blowpipe, according to Tables R to Z. 
 
 EXERCISE XIV. 
 
 238. EXAMINATION OF A LIQUID OF WHICH NOTHING 
 IS KNOWN BUT THAT IT IS A SOLUTION OF A SlNGLE SuB- 
 STANCE, AND NOT OF A MIXTURE. 
 
 A. Observe its smell, taste, and action upon test-papers (18). 
 
 B. Evaporate a little on a slip of glass (p. 20). 
 
 (a) If no residue is left, and the liquid is destitute of 
 
 color, smell, taste, and action on test-papers, it 
 is water only. 
 
 (b) If a residue is left, or if the conclusion is doubtful, 
 
 evaporate a larger quantity of the liquid in a 
 porcelain dish (84), and if there is any residue, 
 
 * Sulphur and phosphorus would of course be recognized in this 
 experiment. 
 
182 UNKNOWN LIQUIDS EXAMINED. 
 
 examine it as directed for an unknown solid sub- 
 stance (237). Carefully observe whether any 
 odor is evolved during the evaporation. 
 
 Whilst the evaporation is proceeding, the analyst may 
 examine another portion of the solution by Tables A and H. 
 
 (c) If no residue is left on evaporation, and the liquid 
 is acid to test-papers, examine for 
 
 Sulphuric acid (102) 
 Hydrochloric acid (105) 
 Nitric acid (109) 
 Acetic acid (149) 
 Sulphurous acid (100) 
 Chloric acid (90) 
 Formic acid (150) 
 Lactic acid (232) 
 
 Butyric acid (215) 
 Hydriodic acid (93) 
 Hydrofluoric acid (89) 
 Hydrofluosilicic acid (64) 
 Carbonic acid (95) 
 Hydrocyanic acid (99) 
 Hydrosulphuric acid (97) 
 Valerianic acid (218) 
 
 Oleic acid (233). 
 
 (e?) If no residue is left on evaporation, and the liquid 
 is alkaline to test-papers, examine for 
 
 Ammonia (75) | Aniline (219) | Nicotine (214). 
 
 (e) If no residue is left on evaporation, and the liquid is 
 neither acid nor alkaline, examine especially for 
 
 Alcohol (209) 
 
 Methylic alcohol (211) 
 
 Acetone (212) 
 
 Aldehyde (213) 
 
 Phenole (carbolic acid) (217) 
 
 Ether (221) 
 Chloroform (222) 
 Bitter almond oil (223) 
 Nitrobenzole (224) 
 Benzole (225) 
 
 Glycerine (231). 
 
 When no clue can be obtained, the analyst must carefully 
 go through every step of the analytical processes, commencing 
 at Table A. 
 
FIRST M.B. EXAMINATION. 
 
 183 
 
 
 
 
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184 FIRST M.B. EXAMINATION. 
 
 I. THE SUBSTANCE is SOLID. 
 A. Heat the substance in a small tube. 
 
 (a) It evolves ammonia freely, without blackening. 
 
 Examine especially for 
 
 Urea (182) | Oxalate of urea (192) | Oxalate of ammonia. 
 
 (6) It evolves a pungent odor resembling sulphurous 
 acid. 
 
 Examine for Nitrate of Urea (192). 
 
 (c) It evolves an agreeable odor. 
 
 Examine especially for 
 Benzole acid (154) | Hippuric acid (156) j Acetate of lead (149). 
 
 (d) It evolves an odor resembling that of coal tar. 
 
 Examine especially for 
 
 Cinchonine (170) 
 Quinine (168) 
 
 Sulphate of cinchonine (170) 
 Sulphate of quinine (168) 
 
 (e) It blackens and evolves an odor of burnt ivood or 
 sugar. 
 
 Examine especially for 
 
 Tartaric acid (158) 
 Bitartrate of potash (158) 
 Citric acid (159) 
 Starch (187) 
 Cane-sugar (179) 
 
 Grape-sugar (180) 
 Malic acid (160) 
 Meconic acid (151) 
 Gallic acid (153) 
 Tannic acid (152). 
 
 (/) It blackens and evolves a disagreeable odor of 
 singed animal matter. 
 
 Examine especially for 
 
 Uric acid (161) 
 Urate of soda (161) 
 Urate of ammonia (161) 
 Morphine (165) 
 Hydrochlorate of morphine 
 
 (165) 
 
 Acetate of morphine (165) 
 Meconate of morphine (165) 
 Strychnine (167) 
 Ferrocyanide of potassium (113) 
 Ferridcyanide of potassium (p. 
 84). 
 
 (g) It evolves vapors which provoke violent coughing. 
 Examine especially for Succinic Acid (155). 
 
FIRST M.B. EXAMINATION. 185 
 
 (h) It evolves cyanogen (known by its odor, and pink 
 
 flame). 
 
 Examine especially for Cyanide of Mercury (99). 
 (i) It passes off in vapor without any of the above 
 indications. 
 
 Examine especially for . 
 
 Oxalate acid (115) | Oxalate of ammonia (115). 
 
 B. Heat the substance on a piece of broken porcelain, at 
 first with the ordinary flame, and afterwards ivith 
 the outer blowpipe-flame, 
 (a) A residue is left. 
 
 Moisten it with water, and test with red litmus 
 
 paper. 
 If it be decidedly alkaline, 
 
 Examine for 
 
 Cyanide of potassium (p. 84) 
 Ferrocyanide of potassium (113) 
 Ferridcy anide of potassium(p . 84) 
 Sulphocyanide of potassium (p. 
 
 101) 
 Bitartrate of potash (158) 
 
 Oxalate of potash (115) 
 
 lime (115) 
 Acetate of potash (149) 
 
 " soda (149) 
 
 Urate of soda (161) 
 Tartar emetic (p. 49). 
 
 If the residue is yellow or red, 
 Examine especially for Acetate of Lead (149). 
 (b) No residue is left. Pass on to C. 
 C. Heat the substance with water, 
 (a) It does not dissolve in water. 
 
 Add Potash. 
 If it dissolves in Potash, 
 
 Examine especially for* 
 
 Benzoic acid (154) 
 Hippurie acid (156) 
 Uric acid (161) 
 Gallic acid (153) 
 
 Bitartrate of potasli (158) 
 Urate of soda (161) 
 Urate of ammonia (161). 
 
 * It is not safe to infer the absence of these when the substance 
 dissolves in water. 
 
18G FIRST M.B. EXAMINATION. 
 
 If it does not dissolve, in potash, 
 
 Add Hydrochloric Acid.* 
 It dissolves. 
 
 Examine especially for 
 
 Morphine (165) 
 Quinine (168) 
 Cinchonine (170) 
 Strychnine (167) 
 
 Sulphate of quinine (168) 
 
 " cinchonine (170) 
 
 Oxalate of lime (58). 
 
 (6) It dissolves in -water. 
 
 Test the solution with blue and red litmus paper, 
 
 and, cautiously, by tasting. 
 I. The solution is decidedly acid, but not astringent. 
 
 Examine especially for 
 
 Tartaric acid (158) Malic acid (160) 
 
 Oxalic. acid (115) Meconic acid (151) 
 
 Citric acid (159) Hippuric acid (156) 
 
 Succinic aci'd (155) Bitartrate of potash (158). 
 
 II. The solution is acid and astringent. 
 Examine especially for Gallic (153) and Tannic Acids (152). 
 
 in. TJie solution is alkaline. 
 Examine especially for Cyanide of Potassium (99). 
 
 iv. The solution has a sweet taste. 
 
 Examine especially for 
 
 Cane-sugar (179) | Grape-sugar (180) | Acetate of lead (149). 
 v. The solution is bitter ; pass on to D. 
 vi. The solution has a yellow or green color. 
 
 Examine especially for 
 Ferrocyanide and Ferridcyanide of potassium (p. 80). 
 
 * A blue substance, becoming brown with potash, and again blue 
 with hydrochloric acid, is probably Prussian blue. To confirm, boil 
 with potash, filter, and test the solution with excess of acetic acid, 
 and perchloride of iron. Abundant blue precipitate indicates 
 Prussian blue. 
 
FIRST M.B. EXAMINATION. 187 
 
 vii. The solution is not decidedly acid or alkaline, and 
 has no characteristic taste or color. 
 
 Examine especially for 
 
 Oxalate of ammonia (115) 
 potash (115) 
 
 Acetate of potash (149) 
 soda (149) 
 
 Cyanide of mercury (31) 
 Sulphocyanide of potassium 
 
 (p. 101) 
 Urea (182). 
 
 D. Dissolve a little of the substance in water, or in a little 
 dilute hydrochloric acid, and test with a solution of 
 iodine in iodide of potassium. 
 
 If a brown precipitate is obtained, 
 
 Examine for an alkaloid by Table O. 
 
 If a yellow precipitate is produced, examine for acetate of 
 lead (p. 29). 
 
 If a blue precipitate is produced, examine for starch (187). 
 
 If the iodine solution is bleached, examine for a cyanide 
 (99). 
 
 Should no clue have been hitherto obtained, examine the 
 substance for an organic acid by Table K. and for an organic 
 alkaloid by Table O ; and, as a last resource, for a metal by 
 Table A, and for an inorganic acid by Table G, in the hope 
 that some light may thus be thrown upon the nature of the 
 substance. 
 
 II. THE SUBSTANCE is A LIQUID. 
 
 A. Ascertain whether it has the odor of 
 
 Acetic acid (149) | Hydrocyanic acid (99) | Alcohol (209). 
 
 B. Evaporate a little in a porcelain dish, taking care not to 
 
 continue the heat after the dish is dry, and observing 
 any odor during evaporation. 
 
 (a) If no residue is left, examine for 
 
 Acetic acid (149) 1 Alcohol (209) 
 
 Hydrocyanic acid (99) Glycerine (231). 
 
 (b) If a residue is left, examine the action of heat upon 
 
 it, drawing inferences according to pp. 184, 18o. 
 
188 FIRST M.B. EXAMINATION. 
 
 C. Test a small portion of the solution with a solution of 
 iodine in iodide of potassium. 
 
 If a brown precipitate is obtained, examine another part 
 of the solution for 
 
 Morphine (165) 
 Hydrochlorate of morphine 
 
 (165) 
 Acetate of morphine (165) 
 
 Meconate of morphine (165) 
 Quinine (168) 
 Cinchonine (170) 
 Strychnine (167). 
 
 Yellow precipitate, examine for acetate of lead (p. 29). 
 Blue precipitate, examine for starch (187). 
 If the iodine solution is bleached, examine for a cyanide 
 (99). 
 
 D. Test the liquid with blue and red litmus papers. 
 
 (a) The liquid is acid. 
 
 Add, to a small portion, potash, till it is very 
 slightly alkaline, and stir with a glass rod. 
 
 If a precipitate is produced, add acetic acid in 
 excess; should this fail to redissolve it, exa- 
 mine for Oxalate of Lime (58). 
 
 If acetic acid dissolves the precipitate, examine 
 for 
 
 Acetate of lead (149) I Quinine (168) 
 
 Morphine (165) Cinchonine (170) 
 
 Strychnine (167). 
 
 (b) The liquid is alkaline. 
 
 Add, to a small portion, acetic acid, till it is 
 
 slightly acid, and stir with a glass rod. 
 If a precipitate is obtained, examine for 
 
 Benzoic acid (154) I Uric acid (161) 
 
 Hippuric acid (156) Tartaric acid (158). . 
 
 And for the potash, soda, or ammonia holding them in solution (72). 
 
 If no precipitate is obtained, add to another 
 portion hydrochloric acid (cone.) in slight 
 excess, and stir with a glass rod. 
 
FIRST M.B. EXAMINATION. 189 
 
 Benzoic and hippuric acids would now be precipitated, 
 though they might have escaped precipitation by acetic acid. 
 
 If no clue has yet been obtained, examine the substance 
 for an organic acid by Table K, and for an organic alkaloid 
 by Table O; and, as a last resource, for a metal by Table A, 
 and for an inorganic acid by Table G, in the hope that some 
 light may thus be thrown upon the nature of the substance. 
 
190 
 
 ANALYSIS BY THE BLOWPIPE. TABLE R. 
 
 
 
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REDUCTION ON CHARCOAL. 
 
 191 
 
 EXPLANATIONS AND INSTRUCTIONS ON 
 TABLE R. 
 
 241. To reduce metals on charcoal before the blowpipe 
 Select a piece of hard thoroughly carbonized charcoal, free 
 from crevices, not less than four inches long and one or two 
 inches in diameter ; grind down one of its sides to a flat 
 surface (fig. 73) on the hearthstone. Scoop a very shallow 
 
 Fio. 73. 
 
 Fi. 74. 
 
 cavity at a with the blade of a knife, making it smooth and 
 round. Place in this a grain or two of the substance to be 
 examined, previously reduced 
 to powder (124), and cover it 
 with dry powdered carbonate 
 of soda. Hold the charcoal 
 and the blowpipe in the posi- 
 tions represented in fig. 74. 
 Direct the point of the inner 
 (reducing) flame upon the spe- 
 cimen in the cavity, blowing 
 gently at first lest the powder 
 
 should be scattered, and allow the outer (oxidizing flame) to 
 play over the flat surface of the charcoal. 
 
 Observe very closely the appearances presented by the 
 mass under the influence of heat, especially noticing whether 
 any minute metallic globules are to be seen in the fused 
 
 tluction on charcoal. 
 
102 , INCRUSTATION. LEVIGATION. 
 
 substance. If this be the case, try to fuse them together 
 into larger globules. 
 
 Should an infusible mass be left after the first application 
 of the blowpipe-flame, add more carbonate of soda, and again 
 heat intensely, since the binoxide of tin often requires re- 
 peated additions of carbonate of soda to bring it into fusion 
 and reduce it to the metallic state. 
 
 Watch the appearance of the mass after withdrawing it 
 from the flame, noting any changes of color which may 
 occur in cooling. 
 
 The surface of the charcoal is generally covered, for some 
 distance beyond the cavity, with a deposit or incrustation 
 which sometimes consists of a thin white film of ash left after 
 the charcoal has burnt away, and sometimes of a more 
 opaque coating of some metallic oxide formed by the com- 
 bustion of metallic vapor in passing through the outer flame. 
 
 Observe very carefully the color and general appearance 
 of this incrustation, comparing the results with Table S. 
 
 If any globule of metal is visible, detach it carefully from 
 the fused mass with the point of a knife, place it upon a hard 
 surface, such as a porcelain slab or the bottom of an inverted 
 mortar, and press it with a knife-blade, to ascertain whether 
 it is malleable or brittle. Compare the results with Table S. 
 
 When no metallic globule is visible, or when the metallic 
 globule has been removed, scrape the mass, together with the 
 particles of charcoal in contact with 
 FlG - 75 - it, into a small agate mortar (fig. 75), 
 
 moisten it with one or two drops of 
 water, and grind it into a paste. Stir 
 this paste up with more water, then 
 Agate mortar. fill the mortar with water, allow it to 
 
 rest for a few seconds, in order that 
 
 any metallic particles may subside, and carefully pour off the 
 water, carrying with it the lighter particles" of charcoal and 
 
LEVIGATION. BROWN SLAG. 193 
 
 slag (fig. 76). Repeat this grinding and levigation until 
 metallic particles are distinctly visible at the bottom of the 
 mortar, or until the whole has been washed away without 
 showing any metal. 
 
 FIG. 76. 
 
 Levigatiou in blowpipe analysis. 
 
 The metals which are generally detected in this way, 
 are 
 
 Copper, which gives characteristic red spangles. 
 
 Tin, in white silvery spangles of considerable size. 
 
 Iron, in gray metallic powder, attracted by the magnet. 
 
 242. Fused carbonate of soda is absorbed into the pores 
 of the charcoal, but very frequently a slag is formed which 
 refuses to sink into the charcoal, and remains on the surface.* 
 This is the case with silicate and borate of soda, formed when 
 silicic and boracic acids are present. Sulphide of sodium 
 also generally remains on the surface of the charcoal as a 
 brown mass, the formation of which renders it highly probable 
 that the substance under examination is a sulphide. 
 
 Although most metallic oxides would be reduced to the 
 metallic state by the combined action of the blowpipe-flame 
 and the charcoal support, it is necessary to add carbonate of 
 soda for the following reasons : 
 
 (1) The carbonate of soda removes any acid (silicic acid, 
 
 * Cyanide of potassium will occasionally assist in getting rid of 
 such slags. 
 17 
 
194 BLOWPIPE ANALYSIS. BORAX-BEADS. 
 
 for example) or non-metallic element (such as sulphur) which 
 would hinder the separation of the metal. 
 
 (2) By thus forming a slag through which the metal may 
 sink, the re-oxidation, and in some cases the volatilization, 
 of the metal, are in great measure prevented. 
 
 (3) Carbonate of soda, strongly heated with charcoal, yields 
 vapor of sodium, which acts as a powerful reducing agent 
 upon metallic compounds. 
 
 242. When the substance is heated by itself on char- 
 coal it may furnish any of the results indicated in Table S, 
 and, in addition, other information may often be ob- 
 tained more easily than when carbonate of soda has been 
 added. 
 
 (1) The substance passes away entirely in the form of 
 vapor. Probably mercury, arsenic, or ammonium is present. 
 See Table II, col. 5. 
 
 (2) An infusible mass remains upon the charcoal. Proba- 
 bly aluminium, zinc, or magnesium is present. See Table 
 R, col. 4. 
 
 (3) A sparkling combustion of the charcoal takes place. 
 Probably a nitrate or a chlorate is present. See Table W. 
 
 (4) A smell of burning sulphur is perceived. Probably 
 sulphur or a sulphide or sulphate -is present. See Tables X 
 and Z. 
 
 243. To detect metals by the colors which they impart to 
 a bead of borax-glass Take a piece of platinum wire, of 
 
 such a thickness 
 
 FlG - 77 - that three inches 
 <?HS ^Sj! St weigh one grain, 
 
 Platinum for borax-beads. and Seal it into 
 
 a glass handle as 
 
 described at p. 78. Bend the end of it round into a small 
 loop (fig. 77), which must not be larger than the transverse 
 section of the blowpipe-flame. 
 
BLOWPIPE ANALYSIS. COLORED FLAME TEST. 195 
 
 Make this loop red hot, 
 and dip it into powdered 
 borax, of which a consider- 
 able quantity will stick to 
 the wire. Fuse this in the 
 blowpipe-flame (fig. 78) to 
 a bead which should be per- 
 fectly colorless and trans- 
 parent even after cooling. 
 
 FIG. 78. 
 
 Borax-bead test. 
 
 Place one or two small 
 
 particles of the substance under examination upon a piece of 
 paper close at hand, heat the borax-bead, and touch one of 
 the particles with it so that it may stick to the bead. 
 
 Fuse the bead at the extreme point of the outer (oxidiz- 
 ing) flame of the blowpipe, until the substance appears to 
 have been dissolved by the borax, and observe the color of 
 the bea-d while hot and after cooling. Should the bead be 
 opaque, too large a quantity of the substance has been added, 
 and the experiment must be repeated. 
 
 If the bead remains colorless, another particle of the sub- 
 stance must be fused with it, and so on, until a reasonable 
 proportion has been added without producing any result. 
 
 The bead is afterwards exposed to the point of the inner 
 (reducing) flame of the blowpipe, and the color of the glass 
 carefully observed. 
 
 The results are compared with Table T. 
 
 To clean the wire for a new test, dip the red-hot bead into 
 water, when it will become brittle and may be easily detached 
 from the loop, which is then opened and the wire scraped 
 clean with the thumb-na !. 
 
 244. To detect metals by the color which they impart to 
 the blow pipe-flame. Take a straight piece of platinum wire, as 
 
196 BLOWPIPE ANALYSIS. COLORED FLAME TEST. 
 
 recommended at p. 78, dip it in hydrochloric acid,* and expose 
 it repeatedly to the point of the inner (reducing) blowpipe- 
 flame till it no longer imparts a distinct color to the outer 
 flame. Again moisten it with hydrochloric acid, take upon 
 it a minute quantity of the substance under examination, 
 and again expose it to the point of the inner flame (fig. 79). 
 
 FIG. 79. 
 
 Compare the results with Table U. 
 
 Some metals (barium, for example) so fuse into the plati- 
 num that it is scarcely possible to get rid of them in order 
 to prepare the wire for a fresh test. When this is found to 
 be the case, the extremity of the wire must be cut off. 
 
 245. To detect metals by the cobalt test before the blow- 
 pipe. The solution of nitrate of cobalt should contain about 
 one part of the salt dissolved in ten parts of water, and is 
 conveniently kept in a bottle provided with a perforated cork 
 carrying a piece of glass tube long enough to reach to the 
 bottom of the bottle and to project an inch or two above the 
 cork (fig. 80). This tube should be partly closed at each 
 end by directing the blowpipe-flame upon it. When the upper 
 orifice of this tube is closed with the finger (fig. 81), and the 
 tube withdrawn from the bottle, the cobalt solution is retained 
 
 * This wire should not be dipped into the bottle of hydrochloric 
 acid, but into a small quantity of the acid in a small glass or por- 
 celain capsule. 
 
BLOWPIPE ANALYSIS. 
 
 197 
 
 FIG. 80. 
 
 FIG. 81. 
 
 FIG. 82. 
 
 in it by atmospheric pressure, and may be suffered to fall, drop 
 by drop, upon the mass under examination. One or two 
 drops will generally suffice. An intense heat should then be 
 applied for several seconds, the result being compared with 
 column 4 of Table R, p. 190. 
 246. To detect mercury, 
 arsenic, and ammonia by the 
 blowpipe Dry the carbon- 
 ate of soda by heating it 
 moderately on a piece of glass 
 or tin-plate, or on the blade 
 of a spatula. Allow it to cool, 
 and mix it with the powdered 
 substance under examination, 
 upon a piece of paper, using 
 at least six times as much 
 carbonate of soda as of the 
 substance. Scrape enough 
 powder off a piece of charcoal 
 
 to impart a dark-gray color to the mixture. Introduce the 
 mixture into a small dry German glass tube (p. 33), cleanse 
 the upper part of the tube from adhering particles of sub- 
 stance with a match stick or a roll of paper, and rap the tube 
 against the table so as to shake the powder into the position 
 
198 BLOWPIPE ANALYSIS. 
 
 shown in fig. 82, leaving a clear passage for the vapor. Hold 
 the tube in a narrow band of folded paper,* and heat it in 
 the non-luminous part of the flame (fig. 83) so as not to smoke 
 it. If none of the results mentioned in column 5 of Table 
 R (page 190) are observed, direct the blowpipe-flame upon 
 the bottom of the tube until the glass begins to fuse. 
 
 Beginners frequently fail in this test, in consequence of 
 their allowing condensed water to trickle back upon the hot 
 mixture, causing it to spirt up and soil the sides of the tube. 
 
 NOTES TO TABLE R. 
 
 247. Great care is necessary to avoid error in applying 
 the blowpipe test for aluminium. 
 
 The solution of nitrate of cobalt itself leaves a blue mass 
 of the anhydrous nitrate when evaporated to dryness by the 
 heat of the flame ; but when this blue mass is strongly heated, 
 it is converted into the black oxide of cobalt, whereas the 
 blue mass furnished by the combination of alumina with 
 oxide of cobalt (aluminate of cobalt) becomes of a brighter 
 blue color when more intensely heated. 
 
 The alkaline phosphates and borates also give a blue mass 
 with nitrate of cobalt, but this mass assumes the condition of 
 a fused glass, whilst the alumina blue is perfectly infusible. 
 
 To ascertain what compound of aluminium is under exami- 
 nation, the analyst should refer to p. 59. 
 
 248. The presence of zinc should be confirmed by ob- 
 serving that the infusible mass, before the addition of nitrate 
 of cobalt, is yellow while hot, and becomes white on cooling. 
 
 To ascertain what compound of zinc is under examination, 
 the analyst should refer to p. 61. 
 
 * If any moisture is seen to condense on the sides of the tube, 
 hold the latter with its mouth somewhat inclined downwards, lest 
 the drops should run back and crack the glass. 
 
BLOWPIPE ANALYSIS. 199 
 
 249. The pink color of the compound formed by mag- 
 nesia with oxide of cobalt is very pale, and might be over- 
 looked in a cursory inspection, especially if the observer be 
 dazzled by the incandescence of the ignited mass. 
 
 To ascertain what compound of magnesium is under ex- 
 amination, the analyst should refer to p. 23. 
 
 250. The globules of mercury composing this sublimate 
 are sometimes so minute that it has the appearance of a gray 
 coating upon the tube ; on rubbing it with a lucifer- match 
 stick, the particles unite into distinct globules. 
 
 To ascertain what compound of mercury is under exami- 
 nation, the analyst should refer to pp. 27 and 40. 
 
 251. If arsenic be present, a garlic odor will generally 
 be perceptible at the mouth of the tube, and should have been 
 already noticed in column 1. 
 
 A black shining ring is sometimes formed upon the sides 
 of the tube, in cases where no arsenic is present, in conse- 
 quence of the deposition of a coating of lustrous carbon from 
 the action of heat upon tarry matters, distilled, either from 
 imperfectly prepared charcoal, or from organic matter in the 
 substance analyzed. 
 
 Sulphide of mercury may also furnish a black ring if the 
 quantity of carbonate of soda employed in the experiment is 
 insufficient to remove the whole of the sulphur. 
 
 To ascertain that the ring does really consist of arsenic, 
 make a deep file-mark on each side of it, and break off the 
 glass with a jerk. Wrap the piece of glass containing the 
 ring in a piece of stout paper, and break it, with a few blows, 
 into fragments, but not into powder. Select those fragments 
 which appear to be well-coated, place them in a small tube 
 sealed at one end, and heat them gently above the point of 
 an ordinary flame as shown in fig. 84. The arsenic will be 
 slowly converted into vapor, combining with the oxygen of 
 
200 
 
 BLOWPIPE TEST FOR ARSENIC. 
 
 the air in the tube to form arsenious acid, which will be de- 
 posited in small brilliant crystals upon the cooler part of the 
 tube. Under the microscope, the octahedral shape of these 
 crystals will be distinctly seen (fig. 85). 
 
 Fro. 84. 
 
 FIG. 85. 
 
 If there be more arsenic than can be oxidized by the air 
 in the tube, a dark ring of arsenic will accompany the crys- 
 tals, and may be oxidized by a second sublimation. 
 
 The smallest fragment of arsenious acid may be identified 
 with perfect certainty in the following manner : 
 
 Draw out a piece of narrow German tube to a long point 
 (17), and seal it in the blowpipe-flarne. Drop into this point 
 
 the fragment supposed to be 
 FIG. 86. arsenious acid. Place three 
 
 or four little pieces of char- 
 coal in the wider part of 
 the tube (fig. 86), and heat 
 them to redness in the 
 blowpipe-flame. Then heat 
 quickly the point of the 
 tube so as to drive the 
 
 vapor of arsenious acid over the red-hot charcoal, which will 
 remove the oxygen of the arsenious acid, and a shining black 
 ring of arsenic will be deposited upon the cooler part of the 
 tube. 
 
 To ascertain what compound of arsenic is under examina- 
 tion, the analyst should refer to (35). 
 
BLOWPIPE TEST FOR ANTIMONY. 
 
 201 
 
 252. An odor of ammonia might also arise in this ex- 
 periment, from the decomposition by heat of organic matters 
 containing nitrogen ; but such substances would be car- 
 bonized or blackened when heated in a small tube by them- 
 selves, and would evolve vapors having the offensive smell 
 of singed hair, and restoring the blue color to red litmus 
 paper. 
 
 To ascertain what compound of ammonium is under exa- 
 mination, the analyst should refer to (75). 
 
 TABLE S. 
 253. Metals reduced on Charcoal. 
 
 
 Metallic Globules. 
 
 Incrustations. 
 
 Remarks. 
 
 Antimony 
 
 Very brittle 
 
 White 5 
 
 Metal volatilizes 
 
 
 
 White 
 
 (254, 255). 
 Garlic fumes (256) 
 
 Bismuth, . 
 
 Brittle 
 
 Yellow j 
 
 Metal very fusible 
 
 Copper . . . 
 Lead 
 
 Red, malleable .. 
 Soft, malleable.. 
 
 Little or none. < 
 Yellow s 
 
 (257). 
 Difficult to fuse 
 (258, 259, 260). 
 Metal marks paper 
 
 Silver .... 
 
 Malleable 
 
 Little or none < 
 
 (261, 262, 263). 
 Not oxidizable 
 
 Tin 
 
 Malleable 
 
 Little or none < 
 
 (264, 265). 
 Easily oxidizable, 
 
 Zinc 
 
 None j 
 
 Yellow, hot ; "i 
 white when 
 cold ) 
 
 very fusible (266). 
 
 Infusible mass 
 emitting a greenish- 
 white light (267) 
 
 
 V. 
 
 
 
 NOTES TO TABLE S. 
 
 254. Antimony is generally reduced by the blowpipe in 
 minute globules, which are not easily united into a large 
 
202 BLOWPIPE TEST FOR BISMUTH. 
 
 globule. It is easier to obtain a large globule of antimony if 
 cyanide or ferrocyanide of potassium is employed instead of 
 carbonate of soda. 
 
 Antimony generally gives off a white smoke, and covers 
 the charcoal with an incrustation even beyond the limits 
 of the oxidizing flame. The incrustation generally appears 
 bluish-white, the black charcoal being seen through it. 
 
 The globule of antimony is extremely brittle, falling to a 
 metallic powder when struck or pressed. The metallic ap- 
 pearance of the powder must be observed, or else brittle glo- 
 bules of slag may be mistaken for antimony. 
 
 255. The compounds of antimony most likely to be met 
 with in blowpipe analysis, are 
 
 Sulphide of antimony, Tartar emetic, Oxide of antimony. 
 
 These substances have been described at (39). 
 
 To that description it may here be added, that 
 
 Sulphide of Antimony gives a brown mass when fused 
 with carbonate of soda on charcoal (242). 
 
 Tartar emetic crackles (decrepitates) and sparkles (scin- 
 tillates) when heated alone on charcoal, at the same time 
 giving the violet flame of potassium. 
 
 256. The presence of arsenic should be confirmed as in 
 column 5, Table R. 
 
 When arsenic has been discovered, (35) should be referred 
 to, in order to ascertain whether the substance under exami- 
 nation is one of those described there. If it is not then 
 identified, the blowpipe examination must be continued, with 
 the view of discovering another metal, since arsenic is often 
 present in considerable quantity in ores of which it does not 
 form the most important ingredient. 
 
 257. Bismuth is often mistaken for lead by beginners, 
 because a globule of this metal is flattened when struck or 
 pressed, as if it were malleable ; but if the flattened bead be 
 touched with the point of the knife, it will be found to break 
 to pieces, which is never the case with lead. 
 
 Should any doubt exist as to the presence of bismuth, 
 
BLOWPIPE ANALYSIS. ROASTING. 203 
 
 heat a portion of the substance, on charcoal, with a mixture 
 of equal parts of sulphur and potassium iodide, when bis- 
 muth will give a bright red incrustation on the cooler part 
 of the charcoal. 
 
 The compounds of bismuth which are most frequently met 
 with, are described at (29). 
 
 258. Although compounds of copper are easily reduced to 
 the metallic state before the blowpipe, a beginner generally 
 experiences some difficulty in obtaining a globule of mal- 
 leable copper. The metal first presents itself as a red-brown 
 mass, apparently infusible ; but if this be exposed to the point 
 of the blue inner flame, which is the hottest region orjjocus 
 of the blowpipe-flame, it fuses into a metallic globule of tough 
 copper which requires a sharp blow to flatten it. 
 
 This experiment affords an excellent lesson in finding the 
 focus of the flame. 
 
 259. Copper compounds containing sulphur or arsenic 
 yield a brittle globule when reduced ; to avoid this, such 
 compounds must be well roasted before adding carbonate of 
 soda, by exposing them, on charcoal, to the point of the outer 
 (oxidizing) flame so long as th'ey exhale any odor of sul- 
 phurous acid, or any garlic odor indicating arsenic. 
 
 260- The distinctive characters of the principal com- 
 pounds of copper have been mentioned at (27). 
 
 Beside these, the blowpipe analyst is likely to meet with 
 
 Copper pyrites, composed of copper, iron, sulphur. 
 
 Gray copper ore, ' < { ^ulpku' antim ny ' ai ' SenlC ' and 
 
 Copper Pyrites, Cu 2 S.Fe 2 S 3 , may generally be recognized 
 by its yellow color and metallic lustre ; some of its varieties 
 {peacock ore) exhibit beautiful rainbow tints. The presence 
 of iron may be proved either by extracting the magnetic 
 particles from the slag and surrounding charcoal by leviga- 
 tion, as directed in (2-il), or by fusing a particle of the ore 
 with a bead of borax (243),. in a very hot reducing (inner) 
 
204 BLOWPIPE TEST FOR LEAD. 
 
 flame, when the ferrous oxide will impart a bottle-green 
 color to the glass, if the temperature be sufficiently high to 
 fuse the copper into a minute globule which separates from 
 the borax. 
 
 Gray Copper Ore has a steel-gray color and metallic lustre. 
 
 If it be heated alone on charcoal before the blowpipe, the 
 sulphur and arsenic may be recognized by their characteristic 
 odors, and the antimony by its white incrustation. 
 
 To obtain a bead of malleable copper from gray copper 
 ore, it must be well roasted (in powder) in the outer flame 
 until no more smell of sulphur or arsenic is perceptible, then 
 reduced in the inner flame, with addition of carbonate of 
 soda, and the metallic globule exposed to an intense and pro- 
 longed heat at the point of the inner flame to volatilize the 
 antimony. 
 
 Brass (Copper and Zinc) is recognized by its giving the 
 incrustation of oxide of zinc, which is yellow when hot, and 
 becomes white as it cools. All the zinc may be expelled by 
 protracted heating in the point of the inner flame, and mal- 
 leable copper will be left. 
 
 Gun-metal (Copper and Tin) yields a globule which has 
 externally the color of copper, but it is very much harder. 
 By judicious exposure to the outer flame the bulk of the tin 
 may be oxidized ; and if a little more carbonate of soda be 
 then added, and the reducing flame applied, a globule of 
 nearly pure copper may be obtained. 
 
 261. Lead is very easily recognized in this experiment 
 by the facility with which a globule of metal of considerable 
 size may be obtained, and by the softness of the globule, 
 which admits of being flattened out and cut with a knife. If 
 the flattened globule be taken between the finger-nails, or 
 upon the point of a knife, and drawn across a piece of paper, 
 it leaves a pencil-mark. 
 
 262. The principal compounds of lead may be identified 
 by the characters described at (14). 
 
 Galena (sulphide of lead), the principal ore of lead, when 
 
CUPELLAT1ON ON CHARCOAL. 205 
 
 fused on charcoal with carbonate of soda, gives a brown slag 
 containing sulphide of sodium, and if an insufficient quantity 
 of carbonate of soda be employed, the globule of lead is often 
 somewhat brittle from the presence of sulphur. This may 
 be avoided by roasting the powdered galena in the outer 
 flame as long as it smells of sulphur, before adding the 
 carbonate of soda. Cyanide or ferrocyanide of potassium 
 will furnish malleable lead with galena, without previous 
 roasting. 
 
 Type-metal and shrapnel bullets are composed of lead 
 alloyed with one-fourth of antimony, which renders the 
 alloy hard and brittle. By exposing it for some time to 
 the point of the reducing (inner) flame, all the antimony 
 may be expelled in vapor, and soft malleable lead ob- 
 tained. 
 
 Pewter and Solder, alloys of Lead and Tin, are recognized 
 by their yielding a white infusible dross of binoxide of tin 
 when heated in the outer blowpipe-flame. 
 
 263. Detection of Silver in Lead by the Blowpipe. Cu- 
 pellation. Scoop a bowl-shaped cavity about half an inch in 
 diameter, in a piece of charcoal. Fill this with finely 
 powdered bone-ash, which must be pressed down with the 
 finger so as to fill the cavity with a compact mass of bone- 
 ash, smooth and slightly hollowed on the surface. Place 
 upon this a small piece of the lead under examination, hold 
 the charcoal quite horizontally, 
 and direct the extreme point 
 of the outer (oxidizing) flame 
 upon the metal (fig. 87). The 
 lead immediately fuses, and 
 the oxide which is formed is 
 absorbed, in the liquid state, 
 by the porous mass of bone- 
 ash, leaving the surface of the 
 globule covered with a very 
 thin film of oxide which ex- 
 18 
 
206 CUPELLATION ON CHARCOAL. 
 
 hibits rainbow tints. When this play of color on the sur- 
 face of the metal ceases, and the globule is no longer dimin- 
 ished in size, it consists of pure silver, which is often no 
 more than a mere speck, though easily recognized by its 
 brilliant whiteness. 
 
 It is sometimes necessary to remove the lead from dross 
 which has collected round it, and to transfer it to a fresh 
 cupel, or bed of bone-ash. 
 
 When the lead contains copper, the surface of the bone- 
 ash exhibits, after cooling, a green stain, whilst pure lead 
 imparts a yellow color. 
 
 The presence of tin obstructs the cupellation, an infusible 
 dross of binoxide of tin being formed upon the surface. 
 Silver may also be detected in bismuth by cupellation. 
 
 264. Silver is very easily reduced to the metallic state 
 before the blowpipe, but a sharp heat is required to fuse it 
 into a globule, which is then easily distinguished from all 
 other metals, by its retaining its bright metallic surface when 
 fused at the point of the outer (oxidizing) flame, and by its 
 characteristic white color. The surface of the silver globule 
 is generally rough and frosted after cooling, in consequence 
 of the disengagement of occluded oxygen in the act of solidi- 
 fying, but it acquires a strong metallic lustre when rubbed. 
 
 The compounds of silver most commonly met with have 
 been described at (12). 
 
 When Chloride of Silver is fused with carbonate of soda 
 on charcoal, the surface of the latter generally becomes COM ted 
 with a white incrustation due to the condensation of some 
 vapor of chloride of sodium. 
 
 265. Detection of Copper in Silver. Cupel a small piece 
 of the silver with a piece of pure lead, as directed at (263), 
 when the copper will be recognized by the green stain pro- 
 duced on the surface of the bone-ash. 
 
 Silver containing copper is blackened when heated in the 
 
REDUCTION OF TIN ON CHARCOAL. 207 
 
 outer blowpipe-flame, becoming covered with a film of black 
 oxide of copper. 
 
 266. It is not easy to obtain a large globule of tin by 
 fusion on charcoal with carbonate of soda. An infusible 
 mass is commonly formed, which can only be reduced by re- 
 peated addition of carbonate of soda and protracted blowing. 
 Minute globules of tin are then easily perceived in the liquid 
 mass, but these are invisible when the slag has solidified on 
 cooling. By levigating the mass (p. 192) large spangles of 
 tin may be obtained. 
 
 If there be any reason for suspecting the presence of tin, . 
 it is advisable to employ coarsely-powdered cyanide of potas- 
 sium instead of carbonate of soda, when a very liquid slag is 
 obtained, in which a large globule of tin maybe formed with- 
 out difficulty. The cyanide of potassium, KCN, abstracts 
 the oxygen and is converted into cyanate of potash, KCNO. 
 Cyanide of potassium covers the charcoal with a white 
 incrustation. 
 
 When cyanide of potassium is not at hand, powdered ferro- 
 cyanide of potassium (yellow prussiate of potash) may be sub- 
 stituted for it, but the globules* of tin then obtained will be 
 rather harder and less fusible, on account of the presence of 
 a little iron. A slight yellow incrustation will also be per- 
 ceived on the surface of the charcoal. 
 
 The chief compounds of tin have been described at (23) 
 and (37). When metallic tin is heated on charcoal before 
 the blowpipe, it yields a decided incrustation which is yellow 
 while hot and white on cooling, and might lead this metal to 
 be mistaken for zinc, but further examination prevents the 
 error (267). This only happens when the unprotected tin 
 is exposed directly to the strong current of the blowpipe 
 flame ; when covered with slag, tin is remarkably fixed even 
 at a very high temperature, and hence yields little or no in- 
 crustation. 
 
 Tin-plate (sheet-iron coated with tin) is at once recognized 
 
20<s 
 
 BLOWPIPE TEST FOR ZINC. 
 
 before the blowpipe by the infusibility of the iron, the tin 
 readily fusing and oxidizing upon its surface. 
 
 267. Zinc, being easily converted into vapor at a bright 
 red heat, does not yield a metallic globule before the blow- 
 pipe, but the formation of the yellow incrustation which is 
 white on cooling enables this metal to be easily detected. By 
 moistening the incrustation with weak solution of nitrate of 
 cobalt, and heating intensely, the green compound of oxides 
 of cobalt and zinc may be produced. 
 
 Compounds of zinc, fused with carbonate of soda, yield 
 eventually an infusible mass which is brilliantly incandescent, 
 that is, emits a white light (with a greenish tinge) when in 
 the flame. This mass is yellow while hot and becomes white 
 as it cools, and if it be moisened with nitrate of cobalt (245), 
 and again intensely heated, it becomes bright green. 
 
 The principal compounds of zinc have been described at 
 (53). Metallic zinc burns explosively when heated on char- 
 coal with the blowpipe, yielding thick white fumes of oxide 
 of zinc. 
 
 TABLE T. 
 268. Colored Beads with Borax. 
 
 
 In outer flame. 
 
 la inner flame. 
 
 Chromium... 
 Cobalt 
 
 Yellowish-green glass.. 
 Blue "lass 
 
 Emerald green glass (269). 
 Blue (270). 
 
 Copper 
 
 Blue glass 
 
 Brown or colorless (271). 
 Bottle reen (272) 
 
 Manganese 
 Nickel 
 
 Purple or pink glass ... 
 Brownish-yellow glass 
 
 Colorless (273). 
 Muddy gray (274). 
 
 NOTES TO TABLE T. 
 
 269. Should the color of the borax-bead leave any doubt 
 as to the presence of chromium, apply the following test : 
 
BORAX-BEADS. 209 
 
 Moisten the loop of platinum wire in the mouth, dip it into 
 dried carbonate of soda, and fuse this into a bead, repeating 
 the operation if necessary until the bead fills the loop. (The 
 bead of carbonate of soda becomes opaque on cooling.) Heat 
 the bead to redness, and take upon it a little nitrate of potash 
 and a particle of the substance under examination. Fuse it 
 for a few moments in the outer blowpipe-flame. If chromium 
 be present, a bright yellow opaque bead will be formed, owing 
 its color to the chromate of soda. 
 
 Should the bead have a blue color (green when hot), it is 
 due to manganate of soda, and indicates the presence of man- 
 ganese. 
 
 The compounds of chromium commonly met with have 
 been described at (61). 
 
 The yellowish tinge of the chromium borax-bead in the 
 outer flame is due to the presence of a little chromic acid, 
 CrO 3 , which becomes reduced to chromic oxide, O 2 O 3 , in 
 the inner flame. 
 
 270. The coloring power of cobalt is very intense, and 
 beginners often take so large a quantity of the substance 
 upon the bead that a black opaque glass is obtained. 
 
 The presence of a little iron renders the cobalt bead green 
 while hot. 
 
 By reduction on charcoal and levigation (241) many of the 
 compounds of cobalt may be made to yield grains of metallic 
 cobalt which might be mistaken for iron, but they are dis- 
 solved by a mixture of hydrochloric and nitric acids to a blue 
 or green solution, which becomes pink when diluted. 
 
 The principal compounds of cobalt have been described at 
 (47). 
 
 Cobalt ores generally contain arsenic, sulphur, bismuth, 
 copper, iron and nickel, as well as cobalt, 
 
 IS* 
 
210 BLOWPIPE TEST FOR COPPER. 
 
 271. The bead furnished by copper in the outer flame is 
 green while hot, and becomes blue on cooling, but the shade 
 of blue is very different from that given by cobalt. To 
 render the glass colorless in the inner flame, it is necessary 
 that the bead should not be very highly charged with 
 copper, .and should be exposed just in the hottest part, at the 
 extremity of the inner flame, so that the reduced copper may 
 fuse into a small bead and attach itself to the wire. If there 
 be too much copper, or the bead be not sufficiently heated, 
 the bead will assume an opaque brown color, due to the 
 separation of minute particles of copper throughout the 
 mass. 
 
 If a small particle of cyanide of potassium be taken upon 
 the hot bead of borax which has been charged with a com- 
 pound of copper in the outer flame, and the bead be then 
 held for a second or two in the smokeless part of the ordi- 
 nary flame, it at once becomes opaque brown, and if now 
 fused in the outer blowpipe-flame, it becomes opaque blue 
 after cooling. 
 
 The presence of copper should always be confirmed by 
 reduction on charcoal with carbonate of soda. 
 
 The chief compounds of copper have been described at 
 (27). 
 
 272. The colors assumed by the iron-bead in the outer 
 and inner flames will be found to vary much with the quan- 
 
 . tity of iron present. 
 
 The brownish-yellow glass obtained in the outer flame 
 fades very much on cooling, so that if little iron is present 
 it often becomes colorless. 
 
 Since iron is often found in small quantity in substances 
 of which it is not the most important ingredient, the analyst 
 must use some judgment in arriving at a conclusion with 
 respect to the real nature of the substance. 
 
 The principal compounds of iron are described at (45). 
 Sulphate of iron, when strongly heated in a small tube 
 
BORAX-BEADS. . 211 
 
 closed at one end (17), evolves thick white vapors of sul- 
 phuric acid, which strongly redden blue litmus, and are 
 accompanied by an odor of sulphurous acid. The residue 
 left after strongly heating will exhibit, when cold, the cha- 
 racteristic red color of colcothar. 
 
 2J13. Manganese has so great coloring power that even 
 a small quantity will often render the glass opaque. In order 
 to obtain a colorless glass in the inner flame, tlie bead must 
 be held just at the point of a good inner flame, and the de- 
 coloration of this glass affords a good test of the skill of the 
 operator in preserving the distinction between the two flames. 
 If the bead be carefully observed whilst in the reducing 
 flame, it will be seen to become streaky, and at the moment 
 of the disappearance of these streaks the bleaching will be 
 found complete. 
 
 If a minute particle of cyanide of potassium be taken upon 
 the bead of borax which has been charged with manganese 
 in the outer flame, and the bead be heated for a second or 
 two in the smokeless part of an ordinary flame, it becomes 
 quite colorless. 
 
 The presence of manganese should be confirmed by fusing 
 a small particle of the substance with carbonate of soda and 
 nitrate of potash (269) in the outer flame, when an opaque 
 blue bead (manganate of soda) will be obtained (green when 
 hot), which becomes brown when exposed to the inner 
 flame. 
 
 The principal compounds of manganese have been described 
 at (55). 
 
 274. The borax beads of iron and nickel are very com- 
 monly mistaken for each other by beginners, although close 
 observation recognizes the peculiar muddy-gray color pro- 
 duced by the inner flame in consequence of the reduction of 
 a portion of the nickel. 
 
 If a minute particle of nitrate of potash be taken up with 
 the hot bead, and the latter exposed to the outer flame, it 
 
212 BLOWPIPE TEST FOR NICKEL. 
 
 assumes a purple tint due to the formation of borate of nickel 
 and potassium. 
 
 The ordinary compounds of nickel have been described 
 at (49). 
 
 Most nickel ores contain arsenic, sulphur, copper, iron and 
 cobalt, as well as nickel, and since the cobalt has much more 
 coloring power than nickel, it is rarely that the latter metal 
 can be detected in the ore by the blowpipe. 
 
 Nickel-speiss is a compound of arsenic, sulphur, nickel, and 
 often iron and copper, obtained in the preparation of smalt- 
 blue from cobalt ores. It is a dark -gray or greenish -gray 
 mass having a metallic lustre. The arsenic and sulphur can 
 be recognized by the odor evolved when the substance is 
 roasted on charcoal at the point of the outer flame. 
 
 TABLE U. 
 275. Colored Flames. 
 
 Barium 
 
 Calcium (lime) 
 
 Copper 
 
 Potassium 
 
 Sodium...' , 
 
 Strontium... 
 
 Green flame* (276). 
 Red (277). 
 Bluish-green* (258). 
 Violet bluef (279). 
 Yellow (280). 
 Carmine (281). 
 
 * Boracic acid also tinges the flame green, though of a different 
 shade from that produced by barium or copper. The distinctive 
 characters of boracic acid are given at (117). Zinc gives a green- 
 ish tint to the flame, and is sometimes mistaken for barium by 
 beginners (267). 
 
 f Arsenic gives a livid blue color to the flame, which is mistaken 
 by beginners for that produced by potassium ; a white smoke of 
 arsenious acid issues from the arsenic flame. 
 
BLOAVPIPE ANALYSIS. 213 
 
 NOTES TO TABLE U. 
 
 276. A beginner very often fails to obtain the green 
 flame of barium, especially when operating upon the sulphate. 
 To insure success, it is \vell to mix a little of the substance 
 to a paste with a drop of concentrated hydrochloric acid, and 
 to take a very little of this upon the extremity of the wire, 
 which is then held in the point of a sharp blue inner flame. 
 At first the yellow sodium flame is generally seen, but after a 
 short time the grass-green barium flame makes its appearance. 
 
 The green flame may be even more easily obtained by 
 fusing the sulphate of baryta with a bead composed of fluor- 
 spar fused with about twice as much sulphate of lime. 
 
 The tint of the barium flame is very different from that 
 given by copper, and copper should already have been ex- 
 cluded by the tests on charcoal, and with the borax-bead. 
 
 The commonest compounds of barium have been described 
 at (65). 
 
 277. It is not easy to distinguish between the flames of 
 calcium and strontium, unless they are seen side by side. By 
 comparing the color imparted to "the flame by nitrate of stron- 
 tia, with that caused by the substance under examination, the 
 danger of error is much diminished. 
 
 278. The compounds of calcium or lime ordinarily met 
 with have been described at (G9). 
 
 Sulphate of Lime may be recognized by mixing it with an 
 equal quantity of powdered fluor-spar (fluoride of calcium), 
 and heating on a loop of platinum wire, when it fuses easily 
 to a clear glass, which becomes opaque on cooling. 
 
 Phosphate of Lime may be identified by moistening it with 
 a drop of strong sulphuric acid, and exposing it, on platinum 
 wire, to the inner blowpipe-flame, when the phosphoric acid 
 undergoes reduction, and the phosphorus imparts a peculiar 
 livid greenish hue to the outer flame. 
 
 If phosphate of lime be heated in a small tube (17) with 
 metallic magnesium, and the mass, after cooling, be moistened 
 
214 BLOWPIPE TEST FOR SODIUM. 
 
 with water, it evolves the peculiar fishy odor of phospho- 
 retted hydrogen. 
 
 Fluoride of Calcium, when heated on a knife, or on a piece 
 of platinum foil, generally crackles (decrepitates) and emits a 
 peculiar blue light resembling a pale flame of sulphur. When 
 mixed with an equal quantity of sulphate of lime and heated 
 on a loop of platinum wire it fuses easily to a clear glass, 
 which becomes opaque on cooling. 
 
 279. The violet-blue flame of potassium is easily ob- 
 scured toy the yellow sodium-flame. To avoid error from 
 this cause, the flame should be examined through a square 
 of cobalt-blue glass, through which the yellow rays of the 
 sodium-flame are not transmitted. 
 
 The common compounds of potassium have been described 
 at (77). 
 
 Nitrate and Chlorate of Potash would cause vivid combus- 
 tion (deflagration) when heated on charcoal. 
 
 Bisulphate of Potash gives thick suffocating fumes of 
 sulphuric acid when heated before the blowpipe on char- 
 coal. 
 
 Bitartrate of Potash emits the characteristic smell of burnt 
 sugar when heated before the blowpipe. 
 
 Ferrocyanide of Potassium (yellow prussiate of potash) 
 evolves an odor of ammonia when heated. 
 
 280. Since almost every substance contains enough 
 sodium to impart a yellow tinge to the flame, the analyst 
 must hesitate before deciding that sodium is an essential con- 
 stituent of the substance under examination. In order to 
 warrant such a conclusion, the substance must impart a very 
 strong and persistent yellow color to the flame. 
 
 It should also be carefully examined for those characters 
 which are described at (80) as belonging to the ordinary 
 compounds of sodium. 
 
 Chloride of Sodium usually crackles (decrepitates) when 
 heated. 
 
EXAMPLES FOR PRACTICE. 215 
 
 Nitrate of Soda causes vivid combustion {deflagration) 
 when heated on charcoal. 
 
 Hyposulphite of Soda, when heated, melts easily, burns 
 with a blue flame evolving the odor of burning sulphur, and 
 leaves a brown residue of sulphide of sodium. 
 
 Biborate of Soda would be identified by its yielding a 
 borax-bead on a loop of platinum wire. 
 
 Tungstate of Soda, Na 2 WO 4 .2Aq., may be recognized by 
 fusing it with a bead of borax, to which the tungstic acid 
 imparts a pale-yellow color in the outer flame, becoming 
 indigo-blue in the inner flame. 
 
 281. The precaution recommended in (277) should be 
 taken in order to avoid mistaking calcium for strontium. 
 
 The chief compounds of strontium have been described at 
 (67). 
 
 282. EXAMPLES FOR PRACTICE IN EXERCISE XVI. (See 
 
 10.) 
 
 Arsenious acid 
 Chloride of ammonium 
 Binoxide of tin 
 Red lead 
 
 Chloride of silver 
 Oxide of antimony 
 Oxide of nickel 
 Chloride of barium 
 Carbonate of lime 
 Calomel 
 Oxide of zinc 
 Oxide of copper 
 
 Colcothar (peroxide of iron) 
 Oxide of bismuth 
 Binoxide of manganese 
 Oxide of cobalt 
 Nitrate of stroiitia 
 Nitrate of potash 
 Carbonate of soda 
 Lead containing silver and 
 
 copper* 
 
 Oxide of chromium 
 Alum 
 Sulphate of magnesia. 
 
 * Obtained by melting a pound of lead in a crucible with a little 
 borax, dissolving a shilling in it, casting the alloy into a thin plate, 
 on a stone, and cutting it up into fragments. 
 
210 
 
 TABLE V. 
 
 03 ~ 
 
 ^ * kJ 
 
 a o > 
 
 ,2 
 
 G 
 
 t i 
 
 O 
 
 ^ ^ 
 
 
 
TABLE W. 
 
 217 
 
 
 GO 
 
 
 
 
 
 
 (M 
 
 
 
 
 ^L 
 
 
 S*"* 
 
 ^^ 
 
 
 
 
 
 
 1 
 
 CO 
 
 
 g o" 
 
 V / 
 
 
 -d 
 
 vO 
 
 . 
 
 'N 
 
 tc ^-^ 
 
 
 O 
 
 1 
 
 GO 
 GO 
 fM 
 
 lj 
 
 s |- s ^ 
 
 o. ^ G^ 
 
 s 
 
 ll 
 jj 
 
 Brown vapor 
 Characteristic 
 
 Effervescence 
 
 Extremely pni 
 Corrosion of t 
 
 1 yrj ^ V ~ / 
 
 1 o 1 fe - | o 
 'E 3 ^ g- "2 
 
 I^S 5 S >^ 
 
 ill ^3 N 
 
 1 ^ J 3 8 2'i 
 
 O^PQ ?>PH PP P^ 
 
 GO 
 
 -^ 
 
 wW 
 
 
 ^-r- 
 
 ^_ ' -^ 
 
 E-i 
 
 0) 
 
 
 
 
 
 ^ 
 
 H 
 
 
 
 
 
 TO 
 
 a 
 
 
 
 
 
 CO 
 
 o 
 
 
 
 
 
 hj O 
 
 S 
 
 
 
 
 
 PH 
 
 ^ 
 
 
 
 
 
 H *H 
 
 "3 
 
 
 * 
 
 qH 
 
 * 
 
 I-) O 
 
 ' 
 
 " ^^ 
 
 
 *r^ 
 
 
 ro 
 
 ci 
 
 
 
 
 
 3 o> 
 
 
 ff r C 
 
 r ^ w 
 
 Cg 
 
 
 T^ 
 Bisulphat 
 
 Hydrochloric 
 
 II 
 
 o o 
 
 Carbonic aci 
 
 Hydrofluoric 
 
 O * > 
 
 i s I I 
 
 3 1 
 
 ^ 
 
 o> 
 
 
 
 
 
 CO 
 
 
 
 
 
 
 cq 
 
 'o 
 
 - 
 
 - 
 
 - 
 
 ^ ^ N* V* 
 
 
 a; 
 
 
 
 . 
 
 . 
 
 . . 
 
 
 c 
 
 . 
 
 8 
 
 3 
 
 '1 
 
 
 3 
 
 x> 
 
 2 
 
 ^ 
 
 2 >< tf) "^ 
 
 
 
 1 
 
 ^ 
 
 o 
 
 ^o ^ 'i 
 
 
 *^ 
 
 
 
 a 
 
 
 
 3 
 
 ^ 
 
 5 
 
 1 
 
 1^ ^ f^ 
 
218 BLOWPIPE TESTS FOR CHLORIDES. 
 
 NOTES TO TABLE W. 
 
 285. In performing this test, it is seldom requisite to 
 apply the blowpipe-flame. The tube should be held, as 
 represented in fig. 83, in the lower part of an ordinary 
 flame. 
 
 Bisulphate of potash, when raised to a moderately high 
 temperature, evolves vapor of sulphuric acid. The analyst 
 should familiarize himself with the smell of the vapor ob- 
 tained by heating the bisulphate of potash, before proceed- 
 ing to draw a conclusion from this test. 
 
 The action of the bisulphate of potash is due to its power- 
 fully acid character, which enables it to expel acids from 
 their compounds, at a high temperature, much in the same 
 way as strong sulphuric acid itself. 
 
 286. If a little black oxide of manganese or nitrate of 
 potash be mixed with the bisulphate of potash and the 
 suspected chloride, it will evolve chlorine itself on applying 
 heat, which may be recognized by its odor and its power of 
 bleaching test-papers. 
 
 The following blowpipe test is also sometimes employed 
 for the detection of a chloride : 
 
 Make a bead of metaphosphate of soda by fusing micro- 
 cosmic salt (phosphate of soda and ammonia) in a loop of 
 platinum wire, as in the borax-bead test;* take upon this 
 some black oxide of copper, and fuse it in the outer flame of 
 the blowpipe. The bead has a dark -blue color, and does 
 not impart any blue or green color to the outer flame when 
 held in the inner flame. If a small quantity of a chloride be 
 taken up on the hot bead, it will color the outer flame green 
 or blue, when held in the inner flame, in consequence of the 
 formation of chloride of copper. Sulphate of copper may be 
 
 * The loop should be made double to enable the microcosmio 
 salt to hang to it better while being fused. 
 
BLOWPIPE ANALYSIS. 219 
 
 substituted for the oxide, but the color is then usually 
 limited to a bright-blue halo immediately around the bead. 
 Bromides and iodides would produce a similar result, but 
 they would evolve bromine and iodine, respectively, when 
 fused with bisulphate of potash. 
 
 The description of the principal chlorides will be found on 
 referring to the index. 
 
 287. If a little chloride of sodium (common salt) be 
 added to the mixture of bisulphate of potash with the sus- 
 pected nitrate, chlorine will be evolved, and may be recog- 
 nized by its peculiar odor and power of bleaching test- 
 papers. 
 
 If a nitrate is heated upon charcoal, it causes vivid com- 
 bustion (deflagration). 
 
 All nitrates except those of potash, soda, and ammonia, 
 evolve, sooner or later, brown vapor of nitric peroxide, with 
 its peculiar odor, when heated in a tube, by themselves. 
 
 The description of the principal nitrates will be found on 
 referring to the index. 
 
 The ordinary saltpetre of commerce contains chlorides of 
 potassium and sodium, and therefore evolves some chlorine 
 when heated with bisulphate of potash. 
 
 288. The carbonates are of course far more easily recog- 
 nized by their effervescence when moistened with hydrochloric 
 acid in the colored flame test (244). 
 
 289. The odor of hydrofluoric acid is far more painfully 
 pungent than that of hydrochloric acid. 
 
 On breathing upon the mouth of the tube, a little opaque 
 silica is deposited on the glass, from the decomposition, by 
 moisture, of fluoride of silicon resulting from the action of 
 the hydrofluoric acid upo i the silica in the glass. 
 
 The corrosion of the tube is indicated by its peculiar 
 greasy appearance, but can only be fully seen after the tube 
 has been well washed and dried. 
 
 Fluor-spar (fluoride of calcium) and kryolite (fluoride of 
 aluminium and sodium) are the only fluorides commonly met 
 
220 BLOWPIPE ANALYSIS. 
 
 with in blowpipe analysis, and have been described at (59) 
 and '(89). 
 
 290. It must be remembered that chlorine would also be 
 evolved from a chloride mixed with some oxidizing agent 
 (287). 
 
 Chlorates, heated on charcoal, cause vivid combustion 
 (deflagration). 
 
 The chlorates, when moderately heated by themselves, in 
 a small tube, evolve oxygen, recognized by its power of ac- 
 celerating the combustion of a spark at the end of a match 
 when held in the mouth of the tube. 
 
 The only chlorates at all commonly met with, those of 
 potash and baryta, have been described at pp. 82 and 70. 
 
 Hypochlorite of lime, the only hypochlorite likely to be 
 met with, has been described at p. 74. 
 
 291. Any doubt about the presence of iodine could be set 
 at rest by exposing to the vapor a piece of cotton or paper 
 which has been starched ; this would be colored intensely 
 blue by the iodine, if previously moistened. Iodine itself 
 would be recognized by heating it in a tube, when it would 
 fuse and be entirely converted into violet vapor, condensing 
 in black shining scales on the side of the tube. The prin- 
 cipal iodides will be found on referring to the index.- 
 
 292. If a piece of moistened starched paper or cotton be 
 exposed to the vapor of bromine, it acquires a fine yellow 
 color. 
 
TABLE X. 
 
 221 
 
 TABLE X. 
 
 293. Heating in small tube for Non-metals 
 and Acids. 
 
 Acid vapors are 
 evolved without 
 carbonization. 
 
 Either sulphuric, hydrochloric, nitric, or 
 oxalic acid is probably present (294). 
 
 Carbonization takes 
 place. 
 
 Presence of some organic matter ; perhaps 
 tartaric or acetic acid (295). 
 
 Brown acid vapors 
 
 Presence of nitric acid (296). 
 
 Reddish drops of 
 sulphur condense 
 on the sides of 
 the tube. 
 
 Presence of sulphur or a sulphide (297). 
 
 Violet vapors. 
 
 Presence of iodine (298). 
 
 Cyanogen is evolved, 
 burning with a 
 pink name. 
 
 Presence of a cyanide (299). 
 
 Oxygen is evolved 
 and rekindles a 
 spark on the end 
 of a match. 
 
 Presence of a chlorate, a nitrate, or some 
 easily decomposed metallic oxide (300). 
 
 NOTES TO TABLE X. 
 
 Si94. The sulphates are affected by heat in very different 
 degrees. 
 
 Sulphates of potash, soda, baryta, strontia, lime, magnesia, 
 and lead, would not yield acid vapors in this experiment. 
 
 19* 
 
222 BLOWPIPE ANALYSIS. 
 
 Bisulphates of potash and soda give strong fumes of sul- 
 phuric acid. 
 
 Sulphate of ammonia evolves sulphurous and sulphuric 
 acids, and is entirely dissipated by heat. 
 
 Sulphate of iron evolves sulphurous and sulphuric acids, 
 leaving a red residue of peroxide of iron. 
 
 The sulphates of alumina, zinc, manganese, nickel, cobalt, 
 and copper require a much higher temperature to decompose 
 them, and evolve chiefly sulphurous acid. 
 
 295. If tartaric acid be present, a peculiar smell, like 
 that of burnt sugar, is evolved. The acetates also evolve an 
 odor of acetone, which is rather pleasant. 
 
 The tartrates and acetates of potash, soda, baryta, strontia, 
 and lime, when heated, leave a residue composed of charcoal 
 mixed with a carbonate, which effervesces with acids, and in 
 the cases of potash and soda, is very strongly alkaline. 
 
 296. The nitrates of potash and soda do not evolve acid 
 vapors when heated. Nitrate of ammonia is extremely 
 fusible, and is entirely dissipated by heat. 
 
 The other nitrates evolve brown acid vapors when heated. 
 Nitrate of silver requires a high temperature for its decom- 
 position. 
 
 297. "The smell of sulphur would be perceived here. 
 The only common sulphides which give off sulphur when 
 
 heated in a tube are iron pyrites and copper pyrites. 
 
 298. The smell of iodine is characteristic. 
 Indigo blue also gives off violet vapors when heated. 
 Iodide of lead is the only common iodide which evolves 
 
 iodine vapor when heated in a tube. 
 
 299. The smell of cyanogen is very peculiar. 
 
 This gas should burn with a pink flame on approaching 
 the mouth of the tube to a light. 
 
 Cyanides of mercury and silver are the only ordinary cya- 
 nides which evolve cyanogen when heated. 
 
 300. Chlorates yield oxygen more abundantly and at a 
 
TABLE Y. 
 
 223 
 
 lower temperature than the nitrates, and both salts fuse before 
 undergoing decomposition. 
 
 The metallic oxides would not fuse before evolving oxygen. 
 The principal metallic oxides which give off oxygen when 
 heated, are black oxide of manganese, red lead, oxide of 
 mercury, oxide of silver. 
 
 TABLE Y. 
 
 301. Detection of Non metals and Acids on 
 charcoal before the blowpipe. 
 
 Nitrates 
 Chlorates 
 
 Deflagrate, that is, cause vivid combustion of 
 the charcoal. 
 
 Sulphides 
 
 Evolve the odor of sulphurous acid when roasted 
 alone in the outer flame. 
 Yield a brown fused mass with carbonate of soda 
 in the inner flame. 
 
 Silicates 
 Borates 
 
 Yield with carbonate of soda a bead of glass 
 which is not absorbed by the charcoal (242). 
 
224 
 
 TABLE Z. 
 
 
 
 
 
 . 
 
 S 
 
 
 
 
 
 
 
 
 
 
 
 8 
 
 o 
 
 p 
 
 03 
 
 
 
 
 
 
 
 " 
 
 
 fl 
 
 
 fl 
 
 bo 
 
 
 
 
 
 
 
 
 ft 
 
 ^s 
 
 1 
 
 o 
 
 r-J 03 
 "^ 
 
 fl 
 
 g 
 
 
 
 
 
 
 M 
 
 ^ 
 
 J2 
 
 2 
 
 ft -3 
 
 ^ 
 
 ^ 
 
 
 
 
 
 
 i 
 
 pq 
 
 "C 
 
 o 
 
 ! 
 
 m ^ 
 
 03 "^ 
 
 B 
 
 GQ 
 O 
 
 rt 
 
 2 
 fl 
 
 If 
 
 03 CO 
 
 H 
 
 be 
 
 impartt 
 the outer 
 
 CD 
 
 
 
 
 
 _j 
 
 
 'o 
 
 i 
 
 . 1 1 
 
 .5 
 
 5 
 
 
 
 
 
 
 
 
 
 S 
 
 ^H 
 
 
 
 5 
 
 
 
 
 
 
 
 g 
 
 
 
 
 1-rT 03 
 
 
 03 
 
 
 
 
 
 
 
 
 ^ 
 
 
 35 *" 
 
 
 
 
 
 
 
 
 .^ 
 
 
 g fk 
 
 
 
 
 03 "-t 
 
 
 
 
 
 
 O 
 
 . 
 
 fl ? 
 
 
 ^ t> 
 
 ft 
 
 S ? 
 
 . 
 
 
 
 
 
 1 
 
 ? 
 
 'S 
 *| 
 
 e substa 
 le FLUOR 
 
 1 
 
 ll 
 
 | 
 
 cj IS 
 
 il 
 
 fl 
 03 
 
 be 10 
 
 sg 
 
 
 
 
 
 "o 
 
 1 
 
 5 1 
 
 
 ll 
 
 1 
 
 2 
 
 bo 
 P 
 
 
 
 
 
 ^ 
 
 5 
 
 il 
 
 
 G H 
 
 'ft 
 
 ^ 
 .fl 03 
 
 *" 
 
 
 
 
 N 
 
 
 
 
 ^ 
 
 
 
 
 H 
 
 
 
 
 
 y 
 
 s 
 
 
 
 
 
 
 
 
 
 
 
 h- i 
 
 PS 
 
 'd 
 
 
 
 
 
 
 03 
 
 Ti 
 
 
 
 
 <j 
 H 
 
 ^ 
 
 
 o 
 
 
 1 
 
 03 
 
 'o 
 
 ll 
 
 03 
 
 
 
 
 o 
 
 
 03 
 
 1 
 
 J 
 
 1 S 
 
 03 W 
 
 C3 1> 
 
 cS 
 
 
 
 
 [nation for A 
 
 Silicic Acid. 
 
 ike a very small 1 
 CARBONATE OF S< 
 
 S 
 
 ^ > 
 
 'ft 
 
 C 
 
 o 
 
 o 
 
 ft 
 
 1 
 
 successive portk 
 the substance an 
 
 in the outer flan 
 icic Add should d 
 
 nth effervescence, 
 mtually render tl 
 
 ransparent even , 
 cooling. 
 
 ^t 
 
 CO 
 
 
 
 g 
 
 
 99 
 
 
 
 <S 
 
 
 
 03 
 
 
 
 
 
 1 
 
 
 
 
 
 rf 
 
 o5 
 
 
 
 fl 
 
 fl 
 
 
 
 i-H 
 
 PH 
 
 re 
 
 ? 
 
 I 
 
 i 
 
 i! 
 
 
 tJ 
 
 "' 
 
 03 
 
 1 
 
 n-( 
 
 8 
 
 
 
 
 
 
 
 s, 
 
 OJ 
 
 i 
 
 f 
 
 1 5 
 
 tn 
 
 03 
 
 !s 
 
 CARBONATE OF S 
 
 si 
 
 tl 
 
 03 .03 
 
 rfl fl 
 -^ fl 
 fl O 
 
 'o 
 
 fl 
 
 03 
 
 fl S 
 
 S 
 
 6 w 
 1 1 
 
 fl 
 o 
 
 moisten it wi 
 HYDROCHLORIC , 
 
 Sulphuretted hy< 
 is evolved, 
 
 hich blackens t] 
 
 ! 
 
 
 
 
 
 
 i 
 
 
 
 
 C/J 
 
 * 
 
 
BLOWPIPE TESTS FOR SULPHUR AND SILICA. 225 
 
 NOTES TO TABLE Z. 
 
 303. As this test depends upon the formation of sulphide 
 of sodium, any compound containing sulphur would furnish 
 the same result, so that the analyst, before concluding that 
 the substance under examination is a sulphate, must take its 
 general characters into consideration. 
 
 The presence of sulphide of sodium in the fused mass is 
 detected with greater delicacy by dissolving it, on a crucible- 
 lid or in a small capsule, in a few drops of water, and adding 
 a little nitroprusside of sodium, Na 2 FeNO5CN, which gives 
 a fine purple color. 
 
 The following is also a delicate blowpipe test for sulphur : 
 Make a small bead of pure carbonate of soda on a platinum 
 loop (269), and take successive portions of pure silica upon 
 it, until the fused bead remains transparent after cooling. 
 The bead should now remain colorless even when heated in 
 the reducing flame, but if a partible of a substance containing 
 sulphur in any form be added to it, it will assume a brown 
 yellow color in the reducing (inner) flame, due to the forma- 
 tion of sulphide of sodium. 
 
 In very exact analysis, a gas- flame must not be employed 
 in testing for sulphur, since this element is always present in 
 coal-gas, and is absorbed from the flame by the carbonate ot 
 soda. The flame of a spirit or oil lamp is free from sulphur. 
 
 304. This test requires some patience, since it is neces- 
 sary to repeat the addition of silicic acid many times in order 
 to obtain a transparent glass of silicate of soda. The glass 
 is often colored yellow by the presence of a little sulphide of 
 sodium (see 303). 
 
 Boracic acid would also render a bead of carbonate of soda 
 transparent, but the" following test will prevent mistakes. 
 Make a bead with microcosmic salt (286), which is perfectly 
 
221) BLOWPIPE TEST FOR PHOSPHORIC ACID. 
 
 transparent. The bead thus obtained will dissolve nearly 
 every other substance but silica, so that particles of that 
 substance may be seen floating about undissolved in the 
 fused bead. 
 
 305. This extremely delicate test for boracic acid depends 
 upon the production of fluoride of boron, by the action of the 
 hydrofluoric acid resulting from the decomposition of the 
 fluor-spar by the bisulphate of potash. The fluoride of 
 boron tinges the outer flame green. If much sodium be 
 present, the green color is not easily perceived. 
 
 If a platinum wire be moistened with glycerin and a 
 powdered borate be taken upon it, a distinct green tinge will 
 be imparted to the flame when the glycerin is kindled. The 
 presence of sodium does not prevent the color from being 
 seen. 
 
 Borax (biborate of soda) would be easily recognized by 
 its behavior when heated on a loop of platinum wire. 
 
 306. In this test, the phosphoric acid set free by the 
 action of sulphuric acid is deoxidized by the flame, and the 
 vapor of phosphorus which is produced imparts the peculiar 
 livid tinge to the outer flame. 
 
 This test does not give a satisfactory result when much 
 sodium is present. 
 
 If a compound containing phosphoric acid be heated in a 
 tube (17) with a little metallic magnesium, and the mass, 
 after cooling, be moistened with water, the peculiar fishy 
 odor of phosphoretted hydrogen will be perceived. 
 
 The following is the most conclusive blowpipe test for 
 phosphoric acid : 
 
 Mix the compound to be tested with two or three parts of 
 dried boracic acid, arid fuse it in a cavity scooped in charcoal. 
 Thrust into the melted mass about half an inch of very thin 
 iron wire (of which twelve inches weigh one grain) and heat 
 it for two or three minutes in a powerful reducing flame. If 
 phosphoric acid be present, a hard silvery brittle metallic 
 globule of iron containing phosphorus will be formed, which 
 
EXAMPLES FOR PRACTICE. 
 
 227 
 
 may be extracted from the fused mass by wrapping it in stout 
 paper and striking it with a hammer upon the anvil. 
 
 307. EXAMPLES FOR PRACTICE IN EXERCISE XVII. 
 (10). 
 
 Chloride of sodium 
 Carbonate of soda 
 Chlorate of potash 
 Bitartrate o'f potash 
 Nitrate of lead 
 Cyanide of mercury 
 Silica (white sand) 
 Sulphate of baryta 
 
 Nitrate of potash 
 
 Fluor-spar 
 
 Iodide of potassium 
 
 Acetate of lead 
 
 Iron pyrites 
 
 Sulphide of iron 
 
 Boracic acid 
 
 Phosphate of lime (bone-ash). 
 
228 TESTS USED IN ANALYSIS. 
 
 ALPHABETICAL LIST OF THE PRINCIPAL 
 TESTS OR REAGENTS. 
 
 308. ACETATE OF LEAD, or PLUMBIC ACETATE 
 Pb2C. 2 H 3 O 2 , may be obtained at oil and color shops as sugar 
 of lead (14). One ounce is sufficient. To prepare the solu- 
 tion, shake half an ounce with five measured ounces of dis- 
 tilled or rain water, until dissolved, with the exception of a 
 little white carbonate of lead which may be filtered off. 
 
 Scraps of lead partly covered with vinegar, in an open 
 bottle, will give a solution of acetate of lead in the course of 
 a few hours. 
 
 Acetate of Lead is a test for 
 
 Sulphuretted hydrogen . . Black precipitate (97) 
 
 Chromic acid Yellow precipitate (120) 
 
 Iodides Yellow precipitate (93). 
 
 309. ACETIC ACID, C 2 H 4 O 2 , is the acid of vinegar, and 
 is sold by druggists in a diluted state (149). Four ounces 
 will suffice. It must not give any precipitate when mixed 
 with excess of ammonia (5) and sulphide of ammonium. 
 
 By boiling vinegar with powdered wood-charcoal, and 
 filtering it, or much better, by distilling vinegar (227), 
 acetic acid may be obtained sufficiently pure for most pur- 
 poses. 
 
 310. ALCOHOL C 2 H 6 O, of sufficient strength for ordinary 
 use iss old as spirits of wine. The methylated spirit is much 
 cheaper, and answers for most of the uses of alcohol (209, 
 210). Four ounces (or a gill) will suffice. 
 
 311. AMMONIA, NH 3 , is sold by the druggists as liquor 
 ammonia or hartshorn, prepared by absorbing ammoniacal 
 gas in water (75). Eight ounces should be provided. 
 
 It must not give any precipitate with oxalate of ammonia 
 (indicating lime), and very little, if any, with chloride of cal- 
 cium (indicating carbonate of ammonia). 
 
TESTS USED IN ANALYSIS. 229 
 
 Ammonia is a test for 
 
 Copper Bright blue color (26) 
 
 Nickel Violet blue (48) 
 
 Iron (as peroxide) . . . Red brown precipitate (45) 
 Mercury (as a mercurious salt) Gray precipitate (13). 
 
 312. AXTIMONIATE OF POTASH, OF HYDROPOTASSIC 
 
 METANTIMONIATE, K t H 8 Sb t O TJ can be obtained only from the 
 operative chemist (39). Two drachms of the salt should be 
 boiled with five measured ounces of distilled or rain water, in a 
 flask, for a few minutes, and filtered. A drop of the solution 
 stirred with a drop of carbonate of soda upon a slip of glass (fig. 
 27) should give a distinct precipitate upon the lines of friction. 
 
 313. BICARBONATE OF SODA, or HYDROSODIC CARBO- 
 NATE, NaHCO 3 , is sold by the druggist under the name of 
 carbonate of soda, in the form of powder (80). One ounce 
 should be placed in the bottle, and shaken with eight meas- 
 ured ounces of cold distilled or rain water. 
 
 BICHLORIDE OF MERCURY; see PERCHLORIDE OF MER- 
 CURY. 
 
 314. BICHLORIDE OF PLATINUM, or PLATINIC CHLO- 
 RIDE, PtCl 4 (also called chloride and perchloride of platinum 
 and muriate of platina), may be obtained from the operative 
 chemist, generally in the form of a solution in water. It is 
 expensive. Half an ounce will suffice. It should give a well 
 marked precipitate when stirred upon a slip of glass with a 
 drop of a moderately strong solution of nitrate of potash (76). 
 
 To prepare bichloride of platinum, dissolve 10 grains of 
 scrap platinum (or old platinum foil) in a flask, by gently 
 heating it with two measured drachms of strong hydrochloric 
 acid, and half a drachm of strong nitric acid. Pour the solu- 
 tion into a dish, and evaporate it at a gentle heat (fig. 30) 
 till it becomes a syrup which solidifies on cooling. Dissolve 
 this in an ounce and a half of distilled or rain water. 
 
 315. BICHROMATE OF POTASH, or POTASSIC BICHRO- 
 MATE, K 2 O.2CrO 3 , is sold by the operative chemist in crys- 
 
 20 
 
230 TESTS USED IN ANALYSIS. 
 
 tals (61). Half an ounce of the crystals may be dissolved in 
 eight measured ounces of hot distilled water. 
 
 316. BlSULPHATE OF POTASH, Or HYDROPOTASSIC SlJL- 
 
 PHATE, KHS0 4 , is sold in a crystalline form by the operative 
 chemist (77). It is only required for blowpipe analysis. 
 One ounce will suffice. It is generally made in the labora- 
 tory from the residue left in preparing nitric acid. 
 
 317. BoNE-AsH is made by burning bones white in a 
 clear fire, and grinding the ash to a fine powder (56). It is 
 sold by the operative chemist, and is only required for blow- 
 pipe analysis. 
 
 318. BORACIC ACID, H 3 BO 3 , is generally sold by the 
 operative chemist in the crystallized form (117). It is only 
 used in blowpipe analysis. Half an ounce of the crystals 
 should be dried in an evaporating dish placed in an oven or 
 over a low flame, and reduced to powder. 
 
 319. BORAX, Na 2 O.2B 2 O 3 , is sold at the oil-shops in crys- 
 tals (80). An ounce of the crystals should be heated in an 
 evaporating dish, over a moderate flame, till the spongy mass 
 ceases to swell up and evolve steam, when it should be re- 
 duced to powder. 
 
 320. CARBONATE OF AMMONIA, or AMMONIC SESQUI- 
 CARBONATE, 2(NH 4 ) 2 O.3CO 2 , is sold, under the former name, 
 by the druggist, in white lumps (75). Two ounces of 
 the salt should be reduced to powder, and shaken, in the 
 bottle, with six measured ounces of cold distilled or rain 
 water. 
 
 321. CARBONATE OF SODA, or SODIC CARBONATE, 
 Na 2 C0 3 , is best obtained, for use in analysis, from the bicar- 
 bonate of soda commonly sold as a white powder under the 
 name of Carbonate of Soda (80J. This should be heated in 
 an evaporating dish over a Bunsen burner (fig. 35) for a 
 quarter of an hour, so as to drive off half its carbonic acid. 
 After cooling, one ounce of the carbonate may be dissolved in 
 six measured ounces of distilled or rain water. The solution, 
 when acidulated with dilute nitric acid, should give no pre- 
 
TESTS USED IN ANALYSIS. 231 
 
 cipitate with nitrate of baryta (indicating sulphate of soda), 
 or nitrate of silver (indicating chloride of sodium). 
 
 322. CHLORIDE OF AMMONIUM, or AMMONIC CHLORIDE, 
 Nil Cl, is sold under the names of sal-ammoniac arid muriate 
 of ammonia, by the druggist. The crystallized salt is purer 
 than the lumps obtained by sublimation, which are colored 
 brown by iron (75). 
 
 Dissolve one ounce of the salt in eight measured ounces of 
 warm distilled or rain water. 
 
 Chloride of Ammonium is a test for 
 Platinum ..... Yellow granular precipitate. 
 
 323. CHLORIDE OF BARIUM or BARIC CHLORIDE, BaCl 2 , 
 is sold by the operative chemist, as muriate ofbarytes, in crys- 
 tals (65). The solution is made by dissolving half an ounce 
 of the salt in five measured ounces of distilled or rain water. 
 
 324. CHLORIDE OF CALCIUM, or CALCIC CHLORIDE, 
 CaCl 2 , may be obtained from the operative chemist either in 
 crystals, or more commonly in white lumps of dried chloride 
 of calcium (09). One ounce may be dissolved in four mea- 
 sured ounces of distilled or rain water for use as a test. 
 
 Chloride of calcium is easily made by adding chalk, or 
 whitening, or marble, to dilute hydrochloric acid, as long as 
 it is dissolved, boiling the solution till it no longer reddens 
 blue litmus paper, and filtering. 
 
 325. CHLORIDE OF LIME may be purchased at the oil- 
 shops. If good, it is a dry powder which has a strong smell 
 like chlorine, and gives off much chlorine when mixed with 
 dilute sulphuric acid. To make the solution for testing, one 
 ounce of the chloride is rubbed down in a mortar with eight 
 ounces of water, and filtered. 
 
 326. CHLORINE WATER is made by passing chlorine gas 
 into water. A small quantity may be quickly made by pour- 
 ing the gas into a test-tube half full of water, and shaking 
 violently after closing the tube with the thumb. By pouring 
 the gas in three or four times, strong chlorine water may be 
 
232 TESTS USED IN ANALYSIS. 
 
 made in two or three minutes. The gas is prepared by gently 
 warming black oxide of manganese with strong hydrochloric 
 acid, in a test-tube or flask. 
 
 326a. COPPER. Thin sheet copper in pieces about half 
 an inch long and an eighth wide ; or pieces of copper wire 
 may be used ; it may be brightened by immersion in nitric 
 acid and washing. 
 
 Copper (when boiled in a solution acidified with hydrochloric acid) 
 is a test for 
 
 Mercury Bright silvery coating (30) 
 
 Arsenic Dark gray " (33) 
 
 Antimony Purplish " (32) 
 
 Bismuth Light gray " (28) 
 
 327. CYANIDE OF POTASSIUM, or POTASSIC CYANIDE, 
 KCN, is sold by druggists in white lumps (77). These 
 should be coarsely powdered in a mortar. Only small quan- 
 tities should be kept in powder in a well-closed bottle. It is 
 very poisonous. 
 
 Two ounces of cyanide of potassium will suffice for some 
 time. 
 
 328. ETHER, C 4 H 10 0, may be obtained from the druggist, 
 and must be kept in a stoppered bottle (221). One ounce 
 will suffice. Methylated ether is less expensive than pure 
 ether, and should be employed when large quantities are 
 required. 
 
 329. FERRIDCYANIDE OF POTASSIUM, or POTASSIC 
 FERRIDCYANIDE, K 3 FeCy 6 , is sold by the operative chemist 
 in crystals, and is commonly called red prussiate of potash or 
 ferricyanide of potassium (77). Half an ounce of the salt may 
 
 be dissolved in five measured ounces of distilled or rain water. 
 
 Ferridcyanide of Potassium is a test for 
 Iron as a ferrous compound or protosalt . . Blue precipitate (45). 
 
 330. FERROCYANIDE OF POTASSIUM, or POTASSIC FER- 
 ROCYANIDE, K 4 FeCy 6 , is often obtainable from the oil and 
 color shops as yelloiv prussiate of potash, in crystals (77). For 
 
TESTS USED IN ANALYSIS. 233 
 
 testing, half an ounce of the salt may be dissolved in five 
 measured ounces of distilled or rain water. 
 
 Ferrocijanide of Potassium is a test for 
 
 Iron .... Blue precipitate (45). 
 Copper .... Brown-red precipitate (27). 
 
 331. HYDROCHLORIC ACID, HC1, may be obtained from 
 the druggist as a solution of hydrochloric acid gas in water 
 (105). Its common name is muriatic acid. It should be 
 colorless, and strong enough to emit fumes in moderately 
 damp air. Eight ounces of this acid should be provided. 
 
 Dilute hydrochloric acid is made by mixing the strong 
 acid with twice its volume of distilled or rain water. 
 
 The acid must give no precipitate with hydrosulphuric 
 acid (indicating arsenic, chlorine, sulphurous acid, perchloride 
 of iron) or with excess of ammonia (5) and sulphide of am- 
 monium (indicating iron), or with much water and chloride 
 of barium (indicating sulphuric acid). 
 
 332. HYDROFLUOSILICIC ACID, orSiLicoFLuORic ACID, 
 H 2 SiF 6 , is sold by the operative chemist in a diluted state. 
 One ounce will suffice. It must not give any precipitate 
 with solution of nitrate of strontia (indicating sulphuric acid) 
 even on stirring. 
 
 333. HYDROSULPHATE OF AMMONIA, or SULPHIDE OF 
 AMMONIUM, (NH 4 ) 2 S, may be obtained in solution from the 
 operative chemist (75). It must not give any precipitate 
 with sulphate of magnesia (indicating free ammonia). Eight 
 ounces of the solution should be provided, and must be kept 
 in a well-closed bottle. 
 
 Hydrosulphate of ammonia is easily prepared by passing 
 hydrosulphuric acid gas (334) into solution of ammonia 
 until it no longer gives a precipitate with sulphate of mag- 
 nesia. 
 
 334. HYDROSULPHURIC ACID, H 2 S,is prepared bypass- 
 ing sulphuretted hydrogen gas into water until the stopper 
 of the bottle is forced up when the liquid is shaken. 
 
 20* 
 
234 
 
 TESTS USED IN ANALYSIS. 
 
 FIG. 88. 
 
 Fragments of sulphide of iron (procurable from the opera- 
 tive chemist) are placed in a half-pint bottle (6, fig. 88), 
 which is half filled with water. Strong sulphuric acid is 
 poured down the funnel tube (f) in a few drops at a time, 
 until the bubbles of gas pass freely through the wash -bottle 
 (w) which contains a little water. The gas is then passed 
 into the bottle (c), which contains the distilled water to be 
 charged with gas. Any gas which is not absorbed by the 
 water passes into the bottle (eT) containing solution of am- 
 monia. This retains all the gas, and prevents it from con- 
 taminating the air. When this ammonia has become saturated 
 with the gas, so that it no longer precipitates sulphate of 
 magnesia, it may be used as hydrosulphate of ammonia, but 
 it will be long before this point is reached. 
 
 About ten minutes are required to saturate the water in 
 the bottle (c) with a brisk current of gas. 
 
 The parts of this apparatus are connected by vulcanized 
 India-rubber tubing, which may 
 be obtained from the operative 
 chemist. 
 
 Fig. 89 shows a simpler appa- 
 ratus for preparing the solution 
 of hydrosulphuric acid, but since 
 there is no provision for absorb- 
 ing the excess of gas, it can only 
 Hydrosuiphuric acid apparatus, be used in a fume.closet with a 
 
 FIG. 89. 
 
TESTS USED IN ANALYSIS. 235 
 
 ffydrosulphuric Acid is a test for 
 
 Cadmium . . Bright yellow precipitate in ammoniacal solution 
 
 Antimony . . Red precipitate in acid solution (39) 
 
 Zinc .... White precipitate in ammoniacal solution (53). 
 
 335. IODIDE OF POTASSIUM, or POTASSIC IODIDE, KI, 
 is sold in crystals by the druggist (77). It is sometimes called 
 hydriodate of potash. Two drachms of the salt may be dis- 
 solved in five measured ounces of distilled or rain water. 
 
 Iodide of Potassium is a test for 
 
 T , ( Bright yellow precipitate, dissolved 
 
 ( by boiling water (14). 
 
 Q., $ Pale yellow precipitate, whitened 
 
 ' \ by ammonia (12). 
 
 Mercury as a mercuric salt * ****** 
 
 336. IODINE is procurable in the solid form from the 
 druggist (93). Five grains may be shaken with an ounce of 
 water to prepare iodine-water. 
 
 Iodine-water is a test for 
 Starch ..... . . Blue color. 
 
 337. LIME-WATER, CaII 2 O 2 , is sold by the druggist. It 
 should turn reddened litmus distinctly blue. It is prepared 
 by shaking freshly slaked lime with distilled or rain water, 
 allowing the solution to settle in a well-closed bottle, and 
 pouring off the clear liquid. 
 
 338. LITMUS PAPER, both red and blue, may be pro- 
 cured from the operative chemist. 
 
 The coloring matter is made from a species of lichen, the 
 Rocella t-inctoria, and is sold in blue cakes made up with 
 chalk or plaster of Paris. 
 
 To make litmus paper, heat half an ounce of cake litmus 
 with three measured ounces of distilled or rain water for half 
 an hour, and filter the solution. To one-half of it, add a 
 little extremely dilute sulphuric acid, on the end of a glass 
 rod, until it acquires a faint reddish tinge (by daylight). 
 
236 TESTS USED IN* ANALYSIS. 
 
 Add the otlier half of the solution, and immerse, in the blue 
 liquid, strips of white filter-paper, or better, of unsized draw- 
 ing-paper. Hang them on a string to dry, out of the reach 
 of acid fumes. Redden the remaining liquid faintly by stir- 
 ring with the rod dipped in dilute sulphuric acid, and dye 
 some more paper with the solution, to obtain red litmus 
 paper. 
 
 These papers fade when exposed to a strong light. 
 
 339. MICROCOSMIC SALT, NaNH 4 HPO 4 , is used only in 
 blowpipe analysis, and may be obtained from the operative 
 chemist. A very small quantity is used. 
 
 340. MOLYBDATE OF AMMONIA, NH 4 HMo0 4 , is sold by 
 the operative chemist in crystals. It is an expensive salt. 
 Twenty grains may be dissolved in an ounce of distilled 
 water for testing. 
 
 Molybdate of Ammonia is a test for . 
 
 Phosphoric acid . i B^t yellow precipitate in a nitric 
 
 ( solution, on warming (111). 
 
 341. NITRATE OF BARYTA, or BARIC NITRATE, 
 Ba2NO 3 , may be obtained in crystals from the operative 
 chemist (65). Half an ounce of the salt may be dissolved 
 in five measured ounces of distilled or rain water. 
 
 Nitrate of Baryta is a test for 
 
 Snlnhuric arid I Milky wllite precipitate insoluble in 
 
 ' ' ( dilute nitric acid (102). 
 
 342. NITRATE OF COBALT, or COBALTOUS NITRATE, 
 Co2NO 3 , is sold, commonly in solution, by the operative 
 chemist (47). It is required for blowpipe analysis only. A 
 very small quantity will suffice. 
 
 343. NITRATE OF POTASH, or POTASSIC NITRATE, 
 KNO 3 , is sold at the oil-shops as saltpetre (77). It should 
 be kept, for use in analysis, in powder. 
 
 344. NITRATE OF SILVER, or ARGENTIC NITRATE, 
 AgNO 3 , may be obtained from the druggist, in crystals, in 
 
TESTS USED IN ANALYSIS. 237 
 
 fused sticks (lunar caustic) or in solution (12). Two drachms 
 of the crystals may be dissolved in five measured ounces of 
 distilled water. 
 
 Nitrate of Silver is a test for 
 
 Hydrochloric acid or chlorides 
 
 Hydriodic acid or iodides 
 
 White precipitate insoluble in 
 boiling nitric acid ; soluble in 
 ammonia (105). 
 
 Yellow precipitate insoluble in 
 nitric acid. Whitened, but not 
 
 dissolved by ammonia (106). 
 White precipitate, passing rapid- 
 ly through various shades of 
 
 Hyposulphites \ yellow, red, and brown, finally 
 
 becoming black sulphide of 
 silver. 
 
 345. NITRIC ACID, HNO 3 , may be obtained from the 
 druggist (109). Eight ounces should be provided, and must 
 be kept in a stoppered bottle. It should be nearly colorless, 
 and should fume moderately when exposed to air. After 
 dilution with much water, it should not give any precipitate 
 with nitrate of silver (indicating chlorine) or with nitrate of 
 baryta (indicating sulphuric acid). Excess of ammonia (5) 
 followed by sulphide of ammonium should not produce any 
 change in it. 
 
 Dilute nitric acid may be made by mixing the strong acid 
 with twice its volume of distilled or rain water. 
 
 346. NITROPRUSSIDE OP SODIUM, Na 2 FeNOCy 5 , may 
 be procured in red crystals from the operative chemist. It is 
 an expensive salt, very rarely required. A solution of it may 
 be obtained by boiling ferrocyanide of potassium with diluted 
 nitric acid till it ceases to give a blue precipitate with sulphate 
 of iron, then adding an excess of carbonate of soda, boiling, 
 and filtering. The solution should give a fine purple blue 
 color with sulphide of ammonium. 
 
 347. OXALATE OF AMMONIA, Or AMMONIC OxALATE, 
 
 (NH 4 ) 2 C 2 O 4 , is sold by the operative chemist in crystals (75). 
 Two drachms of the salt should be dissolved in six measured 
 ounces of distilled or rain water. 
 
 348. PERCHLORIDE OF IRON, or FERRIC CHLORIDE, 
 
238 TESTS USED IN ANALYSIS. 
 
 Fe a C] 6 , is also called sesq Bichloride of iron and mttriate of 
 iron. It is obtained from the operative chemist in the state 
 of solution in water (45). 
 
 It may be prepared by dissolving iron (wire, nails, or 
 filings) with the aid of heat, in a mixture of dilute hydro- 
 chloric acid with one-fourth of dilute nitric acid, evaporating 
 at a moderate heat till the liquid is syrupy, and diluting 
 with water. 
 
 Perchloride of Iron is a test for 
 
 Ferrocyariides .... Dark-blue precipitate (77) 
 
 Su.phoc^Udes . . . . 
 
 Tannic acid ) . . . . \ Inky-black precipitate or color 
 
 Gallic acid ) . . . . ( (152, 153) 
 
 Hyposulphites ....-[ Resolution, soon becoming color- 
 
 349. PERCHLORIDE OF MERCURY, or MERCURIC CHLO- 
 RIDE, HgCl 2 , is sold by the druggist in the solid form, as 
 bichloride of mercury or corrosive sublimate (31). 
 
 Two drachms of the salt may be dissolved in four meas- 
 ured ounces of water. 
 
 Perchloride of Mercury is a test f 
 
 or 
 
 Tin as a stannous compound ) ,,,, ., 
 
 or protosalt .... } Whlte 
 Iodides ....... Scarlet precipitate (93). 
 
 349a. PERMANGANATE OF POTASH, K 2 Mn 2 O 8 , is sold in 
 solution as Condy's disinfecting fluid. The crystallized salt 
 may be obtained from the operative chemist. Twenty grains 
 of the salt may be dissolved in four ounces of water. 
 
 350. PHOSPHATE OF SODA, or HYDRO-DISODIC PHOS- 
 PHATE, Na 2 HPO 4 , may be obtained, in crystals, from the 
 druggist (80). Half an ounce of the salt may be dissolved 
 in ten measured ounces of distilled or rain water. 
 
 351. POTASH, or POTASSIC HYDRATE, KHO, is sold by 
 the druggist both in solution as liquor potasses, and in the 
 solid form as potassa fusa in sticks (77). About eight ounces 
 of the solution should be provided. One ounce of the solid 
 
TESTS USED IN ANALYSIS. 239 
 
 potash maybe dissolved in eight measured ounces of distilled 
 or rain water. 
 
 The solution of potash should not effervesce strongly on 
 adding an excess of hydrochloric acid (indicating carbonic 
 acid). 
 
 The acidified solution should give but a slight flocculent 
 precipitate (alumina) on adding ammonia in excess. Hydro- 
 sulphate of ammonia added to this solution should give little, 
 if any, dark tinge (indicating iron, lead, or copper). 
 
 Potash is a test for 
 Mercury, as a mercuric salt . Yellow precipitate (31) 
 
 ( Blue precipitate, becoming black 
 Copper < when boiled with excess of pot- 
 
 ash (27) 
 
 Iron, as a ferric compound, or j Red _ brown prec ipitate (45) 
 
 persalt j 
 
 Iron, as a ferrous compound, f Dark green precipitate, becoming 
 
 or protosalt ( brown when exposed to air (45) 
 
 f Wh ite precipitate, becoming brown 
 
 I when shaken with air (55) 
 
 ( Pale green precipitate, insoluble 
 
 ^ lcke { in excess (49) 
 
 Cobalt Blue- precipitate (47) 
 
 C Green precipitate, soluble in excess 
 
 Chromium < to a green solution, precipitated 
 
 ( by boiling (61) 
 Ammonia Odor of ammonia on boiling (75) 
 
 352. PROTOCHLORIDE OF TIN, or STANNOUS CHLORIDE, 
 SnCl 2 , should be prepared by boiling two drachms of tin 
 with half a measured ounce of strong hydrochloric acid. 
 
 The solution may be diluted with two ounces of water, and 
 some metallic tin should be kept in it, to prevent it from 
 becoming converted into stannic chloride by the combina- 
 tion of a portion of its tin with atmospheric oxygen. 
 
 Tin is sold by the operative chemist in the granulated 
 state, which is easily dissolved by hydrochloric acid. 
 
 Tin-foil often contains lead. If this metal be present in 
 the solution of protochloride of tin, it will give a precipitate 
 with dilute sulphuric acid. 
 
240 TESTS USED IN ANALYSIS. 
 
 Frotochloride of Tin is a test for 
 
 Gold Purple-brown precipitate 
 
 Platinum Bright red solution 
 
 Mercury Gray precipitate (31). 
 
 353. STARCH, C 6 H ]0 O 5 A drachm. of white starch is 
 rubbed down in a mortar with a measured ounce of cold 
 water. The mixture is poured by degrees into five ounces 
 of boiling water in a dish. 
 
 Starch is a test for 
 Free iodine . Blue color (93). 
 
 354. SULPHATE OF COPPER, or CUPRIC SULPHATE, 
 CuSO 4 , is sold at the oil-shops as blue copperas or blue 
 vitriol, in crystals (27). Half an ounce of the salt may be 
 dissolved in five ounces of water. 
 
 355. SULPHATE OF IRON, or FERROUS SULPHATE, 
 FeSO 4 , also called protosulphate of iron, is sold at the oil- 
 shops in crystals under the name of copperas or green vitriol, 
 (45). One ounce of the salt may be dissolved in four 
 measured ounces of cold distilled or rain water. 
 
 356. SULPHATE OF LIME, or CALCIC SULPHATE, CaS0 4 , 
 is sold at the oil-shops as plaster of Paris (69). About a 
 drachm of the powder may be heated with half a pint of 
 water for some minutes, with occasional stirring, allowed to 
 stand till cold, and filtered off. 
 
 357. SULPHATE OF MAGNESIA, or MAGNESIC SUL- 
 PHATE, MgSO 4 , is obtained from the druggist as Epsom 
 salts (9). One ounce of the salt may be dissolved in five or 
 six measured ounces of water. 
 
 358. SULPHATE OF MANGANESE, or MANGANOUS SUL- 
 PHATE, MnSO 4 , may be obtained in crystals from the opera- 
 tive chemist (55). One drachm of the salt may be dissolved 
 in two ounces of water. 
 
 Sulphate of Manganese is a test for 
 Hypochlorites .... Dark-brown precipitate (91). 
 
TESTS USED IN ANALYSIS. 241 
 
 SULPHIDE OF AMMONIUM; see HYDROSULPHATE OF 
 AMMONIA. 
 
 359. SULPHURIC ACID, H 2 SO 4 , is sold at the oil-shops as 
 oil of vitriol, which is often of a dark brown color, and unfit 
 for use in analysis. By carefully boiling it in a flask it may 
 be rendered nearly colorless, the organic matter to which 
 the brown color is due being oxidized by one portion of the 
 acid. The flask must be allowed to cool before attempting to 
 pour out the acid. 
 
 It is advisable, if possible, to obtain the nearly colorless 
 oil of vitriol from the druggist. It must be kept in a stop- 
 pered bottle. 
 
 Dilute Sulphuric Acid is made by pouring one measured 
 ounce of oil of vitriol, slowly, with continual stirring, into 
 four measured ounces of water in an evaporating basin, 
 beaker or flask (not in a measure or bottle). The mixture is 
 allowed to cool, and the clear diluted acid poured off from the 
 sulphate of lead which is usually deposited from the common 
 
 acid. 
 
 Strong Sulphuric Acid is a test for 
 
 I Red color, and evolution of yellow 
 Chlorates . . . . j explosive gas (90) 
 Iodine Violet vapors on heating (93). 
 
 360. TARTARIC ACID, C 4 H 6 O 6 , is sold in crystals by the 
 druggist (158), One ounce may be dissolved in four measured 
 ounces of water. 
 
 361. TURMERIC PAPER may be obtained from the opera- 
 tive chemist. Its yellow color soon fades in a strong light. 
 
 To prepare turmeric paper, gently heat one drachm of 
 powdered turmeric (the root of Curcuma longa] in six meas- 
 ured drachms of methylated spirit, till the solution has a 
 bright yellow color. Filter it, and dip white filter-paper or 
 unsized drawing-paper into it. Hang the paper on a string 
 to dry. 
 
 362. WATER If it can be procured, distilled water 
 
 only should be employed in analytical operations. It should 
 
 91 
 
242 TESTS USED IN ANALYSIS. 
 
 be tested in the following manner, each test being performed 
 upon a separate portion : 
 
 1. Evaporate a few drops upon a slip of glass ; scarcely a 
 
 trace of solid matter should remain. 
 
 2. Add Nitrate of Silver ; no turbidity (indicating chlo- 
 
 rides or hydrochloric acid) should be produced. 
 
 3. Add Chloride of Barium ; there should be no turbidity 
 
 (indicating sulphates). 
 
 4. Add Oxalate of Ammonia ; there should be no turbidity 
 
 (indicating lime). 
 
 5. Add Hydrosulphuric Acid ; there should be no dark 
 
 tinge (indicating lead or copper). 
 
 Rain-water, after being filtered, may often be substituted 
 for distilled water. 
 
 Should neither distilled nor rain water be procurable, the 
 analyst should test the common water as directed above, and 
 make a careful note of the results, to be subsequently em- 
 ployed in correcting his analysis. 
 
 Common water may often be in great measure deprived 
 of the lime and magnesia which it contains, by boiling it 
 gently in a kettle for half an hour, allowing it to cool, and 
 filtering from the deposited carbonates of lime and magnesia. 
 
 Any of the arrangements represented at pp. 168171 may 
 be employed for distilling water. 
 
 363. ZINC may be procured at the ironmonger's. Thin 
 sheet zinc cut up into strips will be found very convenient. 
 
 The operative chemist furnishes granulated zinc, made by 
 melting the metal in an iron ladle or earthern crucible, and 
 pouring it, in a thin stream, into a pail of water, from a 
 height of eight or ten feet. 
 
APPARATUS. 
 
 243 
 
 APPARATUS REQUIRED FOR THE QUALITATIVE ANALYSIS 
 OF SINGLE SUBSTANCES. 
 
 364. The following list includes the principal articles 
 which are necessary for the identification of single sub- 
 stances. 
 
 They may be provided for ten or twelve shillings. 
 
 12 test tubes 
 
 Rack with, draining pegs 
 
 Tube-cleaner 
 
 Spirit lamp or gas burner 
 
 3 funnels : 2 oz., 1 oz., oz. 
 
 Filter-paper 
 
 Slips of window-glass 
 
 Glass-rod 
 
 Narrow hard glass tubing 
 
 Blowpipe 
 
 Triangular file 
 
 Platinum wire and foil 
 
 4 oz. evaporating dish 
 
 Half-pint Wedgwood mortar 
 
 Wire triangle 
 
 Wire tripod or retort-stand. 
 
244 
 
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INDEX. 
 
 A CETATE of ammonia pre- 
 1\. pared, 64 
 
 of copper, 37 
 
 of lead, Pb(C.,H 3 2 ) 2 , 29 
 
 for testing, 228 
 Acetates, action of heat on, 133 
 
 common, 133 
 
 Acetic acid, HC. 2 H 3 2 , 133 
 confirmed, 133 
 detected, 129 
 for testing, 228 
 identified, 133 
 
 ether. 133 
 Acetone, 132 
 
 identified, 163 
 Acid reaction, 34 
 
 vapors, 221 
 Acids detected, 91 
 Acroleine, 156 
 Agate mortar, 119 
 Albumen, 154 
 
 soluble, identified, 154 
 Alcohol, extracted, 167 
 
 for testing, 228 
 
 identified, 162 
 
 separated from water, 167 
 Aldehyde identified, 163 
 Alkali waste, 100 
 Alkaline reaction, 34 
 Alkaloids, general test for, 179 
 
 identified, 144 
 Alum, 59 
 
 chrome, 67 
 
 concentrated, 59 
 Alumina, acetate, 60 
 
 hydrate, 58 
 
 phosphate, 109 
 
 silicate, 59, 127 
 
 sulphate, 59 
 Aluminate of soda, 60 
 Aluminium and sodium, fluoride, 
 97 
 
 Aluminium blowpipe test, 190 
 
 common compounds of, 59 
 
 confirmed, 58 
 
 detected, 51 
 
 identified, 58 
 Ammonia, NH 3 , 79 
 
 acetate, 134 
 
 prepared, 64 
 
 alum, 59 
 
 carbonate (NH 4 ) 2 C0 3 , 80 
 
 common compounds of, 79 
 
 detection, 77 
 
 for testing, 228 
 
 hydrochlorate, NH 4 C1, 79 
 
 hydrosulphate (NH 4 HS), 80 
 
 identification, 79 
 
 in excess, 21 
 
 molybdate, 236 
 f muriate, 79 
 " nitrate, 80 
 
 oxalate (NH 4 ) 2 C 2 4 , 80 
 
 sesquicarbonate, 80 
 
 solution, 79 
 
 sulphate, 80 
 
 test for, 239 
 
 urate, 142 
 
 Ammonic carbonate, (NH < ) 2 C0 3 , 
 80 
 
 chloride NH 4 C1, 79 
 
 oxalate, (NH 4 ) 2 C 2 4 , 80 
 
 sesquicarbonate, 80 
 
 sulphide, (NH 4 ) 2 S, 80 
 Ammoiiio-hydric sulphide, 233 
 Ammonium, 79 
 
 blowpipe test, 190, 201 
 
 chloride, NH 4 C1, 79 
 
 common compounds of, 79 
 
 sulphide (NH 4 ),S, 80 
 Amorphous phosphorus, 108 
 Analysis by blowpipe, 190 
 
 liquid tests, 17 
 Anglesite (sulphate of lead), 30 
 
246 
 
 INDEX. 
 
 Aniline identified, 164 
 oxalate, 164 
 purple, 164 
 red, 164 
 
 Animal charcoal, 123 
 Antimoniate of potash, KSb0 3 , 50 
 Antimonic acid, 126 
 Antimony and arsenic distin- 
 guished, 44 
 blowpipe test, 201 
 chloride, 50 
 
 common compounds of, 49 
 confirmed, 48 
 crude, 49 
 detected, 32 
 flowers of, 49 
 gray ore of, 49 
 identified, 48 
 
 in insoluble substances, 126 
 oxide, 49 
 
 potassio-tartrate, 49 
 sulphide, 49 
 sulphuret, 49 
 
 blowpipe test, 202 
 terchloride, 50 
 teroxide, 49 
 tersulphide, 49 
 test for, 235 
 vermilion, 49 
 Apparatus, 243 
 Aquafortis, 106 
 Argand burner, 94 
 Argentic nitrate, 236 
 Argol, 84 
 
 Arseniate of soda, 46 
 Arsenic acid, 46 
 
 and antimony distinguished, 
 
 44 
 
 bisulphide, 46 
 blowpipe test, 190, 199 
 common compounds of, 45 
 confirmed, 42 
 detected, 32 
 
 expelled by roasting, 203 
 identified, 45 
 in ores, 202 
 iodide, 46 
 sulphide, 46 
 tersulphide, 46 
 white, 45 
 
 Arsenietted hydrogen, 44 
 Arsenious acid, 45 
 
 crystals, 42 
 
 Arsenious acid detected, 32 
 
 identified, 45 
 
 reduced, 200 
 Arsenite of copper, 37, 45 
 Astringent substances, 186 
 Aurum musivum, 47 
 
 BANDAGE, caoutchouc, 168 
 Baric chloride, BaCl 2 , 231 
 
 nitrate, Ba(N0 3 ) 2 , 236 
 Barium, 69 
 
 blowpipe test, 212 
 
 carbonate, 69 
 
 chlorate, 70 
 
 chloride, BaCl 2 , 70 
 
 chromate, 70 
 
 common compounds of, 69 
 
 confirmed, 69 
 
 detected, 68 
 
 nitrate, Ba(N0 3 ) 2 , 70 
 
 sulphate, 69, 125 
 Baryta, 70 
 
 blowpipe test, 212 
 
 carbonate, 69 
 
 chlorate, 70 
 
 chromate, 70 
 
 confirmed, 69 
 
 detected, 68 
 
 hydrate, 70 
 
 nitrate, Ba(N0 3 ) 2 , 70 
 
 oxalate, 111 
 
 sulphate, 69, 125 
 
 blowpipe test, 212 
 Barytes, 125 
 
 muriate, 70 
 
 Bases, organic, identified, 144 
 Bending tubes, 172 
 Benzoic acid, detected, 130 
 
 identified, 136 
 Benzine, 166 
 Benzole, 166 
 Benzonitrile, 136 
 Biborate of soda, Na 2 0,2B 2 3 , 89 
 Bicarbonate of soda, NaHC0 3 , 87 
 
 for testing, 229 
 
 Bichloride of mercury for testing, 
 HgCl 2 , 229 
 
 of platinum for testing, 
 
 PtCl 4 , 229 
 Bichromate of potash, 67 
 
 for testing, 229 
 Bismuth, blowpipe test, 202 
 citrate, 140 
 
INDEX. 
 
 247 
 
 Bismuth, common compounds of, 
 
 39 
 
 confirmed, 38 
 detected, 32 
 identified, 39 
 nitrate, 39 
 oxide, 39 
 oxychloride, 39 
 tested for silver, 206 
 trisnitrate, 39 
 Bisulphate of potash for testing, 
 
 KHS0 4 , 230 
 in blowpipe analysis, 
 
 218 
 
 test, 217 
 Bisulphide of carbon identified, 
 
 167 
 Bitter almond oil, 166 
 
 almonds, odor of, 137, 166 
 Black borax bead, 209 
 jack, 61 
 lead, 123 
 
 oxide of copper, 38 
 of iron, 55 
 of manganese, 63 
 sulphide of antimony, 49 
 Bleaching powder, 74 
 Blende, 61 
 Blowpipe analysis, 190 
 
 borax bead test, 194 
 cobalt test, 196 
 colored flame test, 195 
 detection of acids, 216 
 for non-metals, 216 
 for reduction on char- 
 coal, 191 
 
 detection of ammonium, ar- 
 senic, mercury, 197 
 gas, 173 
 
 reduction of metals by, 191 
 spirit, 173 
 
 test in small tubes, 221 
 Blue carbonate of copper, 37 
 crystals, 37 
 flame, 81 
 fused mass, 124 
 indigo, 149 
 iodized starch, 155 
 litmus paper, 235 
 mass, with nitrate of cobalt, 
 
 198 
 
 Prussian, 56, 111 
 smalt, 57 
 
 Blue solution, 37, 57 
 stone, 37 
 
 Turnbull's, 52 
 
 ultramarine, 100 
 
 vitriol, 37 
 Boiling, 19 
 Bone-ash, 64 
 
 for cupellation, 230 
 Bone-black, 123 
 Boracic acid, blowpipe test, 226 
 confirmed, 112 
 crystals, 113 
 detected, 93 
 for testing, 230 
 identified, 113 
 Tuscan, 113 
 Borate of lime, 113 
 Borates, blowpipe test, 226 
 
 detected, 93 
 
 on charcoal, 193 
 Borax, Na./).2B 2 3 , 89 
 
 bead test, 194 
 
 beads, 208 
 
 blowpipe test, 226 
 
 for testing, 230 
 Boron, fluoride, 226 
 Boronatrocalcite, 113 
 Brass, 204 
 Brick, 127 
 Brimstone, 122 
 British gum, 155 
 Bromides, blowpipe test, 220 
 Bromine detected, 96, 103 
 Bronze powder, 47 
 Brown acid vapors, 221 
 
 caramel, 149 
 
 chromate of lead, 30 
 
 color with potash, 154 
 
 ferrocyanide of copper, 111 
 
 haematite, 54 
 
 oxide of lead, 29 
 
 residue with nitric acid, 
 29 
 
 vapors, 103 
 Brucine detected, 144 
 
 identified, 146 
 Brunswick green, 38 
 Bullets, shrapnel, 205 
 Bunsen's burner, 75, 95 
 Burnett's disinfecting fluid, 62 
 Burnt sugar odor, 137 
 Butyric acid identified, 163 
 
 ether, 164 
 
248 
 
 INDEX. 
 
 CADMIUM, test for, 235 
 Caffeine detected, 145 
 Caffeine identified, 145 
 Calamine, til 
 
 electric, 128 
 
 Calcic chloride, CaCl 2 , 74 
 sulphate, CaS0 4 , 73 
 Calcined magnesia, 24 
 Calcium, 71 
 
 blowpipe test, 212 
 carbonate, 72 
 chloride, CaCl 2 , 74 
 common compounds of, 72 
 detected, 68 
 fluoride, 65 
 
 blowpipe test, 214, 219 
 oxalate, 74 
 phosphate, 64 
 
 blowpipe test, 213 
 sulphate, CaS0 4 , 73 
 
 blowpipe test, 213 
 sulphide, 100 
 Calomel, 27 
 
 Cane sugar identified, 152 
 Caoutchouc bandage, 168 
 Caramel identified, 149 
 Carbazotic acid identified, 149 
 Carbolic acid, 164 
 
 identified, 150 
 Carbon, 122 
 
 identified, 116 
 Carbonate of ammonia, 
 
 (NH 4 ) 2 C0 3 , 80 
 for testing, 230 
 precipitate, 68 
 copper, 37 
 lead, 29 
 lime, 72 
 magnesia, 24 
 soda, Na 2 C0 3 , 87 
 bead, 209 
 for testing, 230 
 Carbonates, blowpipe test, 217 
 
 common, 99 
 Carbonic acid, detected, 91 
 
 identified, 99 
 oxide, identified, 111 
 Carbonization by heat, 96 
 Carmine flame, 212 
 Caseine, 159 
 Cast-iron identified, 53 
 Caustic, 26 
 potash, 83 
 
 Caustic soda, 88 
 Cawk, 125 
 Celestine, 71, 125 
 Ceroleine, 159 
 Cerotic acid, 159 
 Cetine, 159 
 Chalcedony, 126 
 Chalk, 73 
 Char, 123 
 Charcoal, animal, 123 
 
 blowpipe, 191 
 
 wood, 123 
 Chili saltpetre, 88 
 Chloral, hydrate, 150 
 Chlorate of baiyta, 70 
 
 potash, 82 
 
 blowpipe test, 220, 222 
 Chlorates, common, 98 
 
 on charcoal, 194 
 
 test for, 241 
 Chloric acid, 98 
 
 detected, 91 
 Chloric peroxide, 97 
 Chloride, mercurous, 27 
 
 of ammonium, NH + C1, 79 
 for testing, 231 
 use in analysis, 23 
 
 of barium for testing, BaCL, 
 231 
 
 of calcium for testing, CaCL. 
 231 
 
 of lead, 30 
 
 of lime, 74 
 
 for testing, 231 
 
 of mercury, HgCl 2 , 27, 41 
 
 of silver, 26 
 
 of tin, 36 
 Chlorides detected, 91 
 
 by blowpipe, 218 
 
 impurities, 103 
 
 test for, 237 
 Chlorine confirmed, 103 
 
 detected, 91 
 
 evolved, 29, 63 
 
 preparation, 232 
 
 water, for testing, 232 
 Chloroform, identified, 165 
 
 tested, 165 
 Chloropicrine, 149 
 Cholesterine identified, 157 
 Chromate of lead, 29 
 
 of potash, K 2 Cr0 4 , 67 
 Chromates detected, 92 
 
INDEX. 
 
 249 
 
 Chrome alum, 67 
 
 iron ore, 66 
 
 orange, 29 
 
 yellow, 29 
 Chromic acid, 114 
 
 detected, 92 
 
 identified, 114 
 
 test for, 228 
 Chromium, 66 
 
 blowpipe test for, 209 
 
 common compounds of, 66 
 
 confirmed, 66 
 
 by blowpipe, 209 
 
 detected, 51 
 
 insoluble compounds, 128 
 
 oxide, 66 
 
 test for, 239 
 
 Cinchonine detected, 144 
 in quinine, 147 
 
 identified, 148 
 
 sulphate, 148 
 Cinnabar, 41 
 Citrates, common, 140 
 Citric acid detected, 130 
 
 identified, 139 
 Classification of metals, 18 
 Clay, 59, 127 
 Cleavage, 31 
 Coal identified, 123 
 Coal-tar odor, 148 
 Cobalt, 57 
 
 blowpipe test, 209 
 
 confirmed, 57 
 
 detected, 51 
 
 glance, 57 
 
 metallic, 57 
 
 nitrate, Co(N0 3 ) 2 , 57 
 
 ores, 209 
 
 oxide, 57 
 
 test for, 239 
 
 test in blowpipe analysis, 
 
 196 
 
 Cobaltous nitrate, 236 
 Coke identified, 123 
 Colcothar, 55 
 Colored beads, 208 
 
 flames, 212 
 
 flame test, 74 
 Common salt, 88 
 Concentrated sulphuric acid, 
 
 H 2 S0 4 , 241 
 Condenser, 168 
 Condy's disinfectant, 63 
 
 Copper, 36 
 
 acetate, 37 
 
 alloys, 204 
 
 arsenite, 37, 45 
 
 blowpipe test, 210, 212 
 
 carbonate, 37 
 
 common compounds of, 37 
 
 confirmed, 36 
 
 detected, 32 
 
 detected in lead, 206 
 
 detection by blowpipe, 203 
 
 ferrocyanide, 111 
 
 glance, 38 
 
 identified, 36 
 
 metals precipitated by, 232 
 
 ore, gray, 204 
 
 oxide, 38 
 
 oxy chloride, 38 
 
 pyrites, 203 
 
 suboxide, 38 
 
 sulphate, CuS0 4 , 37 
 
 sulphide, 38 
 
 test for, 229, 233 
 
 test for nitric acid, 105 
 Copperas, 55 
 Cork borers, 171 
 Corks fitted, 172 
 
 perforated, 171 
 Corrosive sublimate, 31 
 Coughing indicates succinic acid, 
 
 132 
 
 Cream of tartar, S3 
 Crimson flame, 71 
 Crocus, 55 
 Crucible tongs, 117 
 Crushing-mortar, 120 
 Cryolite, 9"J 
 
 Crystals formed on cooling, 30 
 Cupellation, 205 
 Cupric oxide, 38 
 
 sulphate, CuS0 4 , 240 
 Cuprous oxide, 38 
 
 sulphide, 38 
 Cyanide of mercury, 41 
 analysis, 101 
 
 potassium, commercial, 
 
 KCN, 84 
 
 for testing, 232 
 in blowpipe analysis, 207 
 Cyanides, common, 101 
 
 detected, 93 
 Cyanogen, 222 
 
 detected, 93 
 
250 
 
 INDEX. 
 
 DECANTATION, 33 
 Decrepitation, 30, 41, 65 
 Deflagration, 82 
 Deliquescence, 62, 74, 82 
 Dextrine identified, 155 
 Diamond, 122 
 
 mortar, 120 
 
 Dilute hydrochloric acid for test- 
 ing, 233 
 
 nitric acid for testing, 237 
 Dilute sulphuric acid for testing, 
 
 240 
 
 Dinas fire-brick, 127 
 Dish, evaporating, 94 
 Disinfectant, Burnett's, 62 
 
 Condy's, 63 
 Dissolving, 19 
 Distillate, 169 
 Distillation, 168 
 Distilled water, 241 
 Dolomite, 73 
 Dropping-tube, 196 
 
 Tf ARTHENW'ARE, 127 
 
 JL Effervescence, 91 
 Efflorescence, 87 
 Electric calamine, 128 
 Emery, 59 
 Emulsion, 156 
 Epsom salts, 24 
 Essence of mirbane, 166 
 Ether, caution in using, 158 
 
 for testing, 232 
 
 identified, 165 
 Evaporating dish, 94 
 Evaporation, 94 
 
 on glass, 20 
 
 on water-bath, 174 
 Excess, meaning of, 21 
 Explosion with sulphuric acid, 
 97 
 
 FERRIC acetate, 134 
 chloride, Fe,Cl 6 , 56 
 citrate, 140 
 oxide, 54 
 
 salts detected, 52 
 Ferridcyanide of potassium, 
 
 K 3 FeCy 6 , 84 
 
 potassium, for testing, 232 
 Ferridcyanides detected, 100 
 Ferrocyanide of calcium and po- 
 tassium, 111 
 
 Ferrocyanide of potassium, K 4 Fe 
 
 Cy 6 , 84 
 
 Ferrocyanides detected, 110 
 
 test for, 238 
 Ferrocyanogen, 110 
 Ferrous carbonate, 56 
 
 iodide, 56 
 
 oxide, 52 
 
 salts detected, 52 
 Ferrous sulphate, FeS0 4 , 55 
 
 sulphide, 55 
 Fibrous gypsum, 73 
 File, rat's-tail, 171 
 Filters, 20 
 Filtration, 20 
 Fire-brick, 127 
 Fire-clay, 127 
 Flake white, 39 
 Flame, colored, test by, 74 
 Flask for distillation, 170 
 Flint, 126 
 Fluorescence, 147 
 Fluoric acid, 97 
 Fluoride of calcium, 65 
 Fluorides, blowpipe test, 219 
 
 detected, 91 
 Fluorine, 97 
 
 confirmed, 96 
 
 detected, 91 
 Fluor-spar, 65 
 
 blowpipe test, 2] 4 
 Focus of blowpipe-flame, 203 
 Formic acid detected, 130 
 
 identified, 134 
 French chalk, 128 
 Frosted silver, 206 
 Fructose, 153 
 Fruit-sugar, 153 
 Fuller's earth, 127 
 Fulminate of mercury, 101 
 Fumaric acid, 141 
 Fumes, cause of, 96 
 Fuming sulphuric acid, 102 
 Funnel-tube, 170 
 Fusing-point determined, 157 
 Fusion of insoluble substances, 
 120 
 
 pALENA, 30 
 
 VI Gallic acid detected, 130 
 
 identified, 135 
 
 test for, 238 
 Garlic odor of arsenic, 45 
 
INDEX. 
 
 251 
 
 Gas blowpipe, 173 
 
 Gas-burners, 94 
 
 Gas -carbon identified, 123 
 
 Gauze-burner, 95 
 
 Gelatine identified, 155 
 
 German tubing, 33 
 
 Glacial phosphoric acid, 107 
 
 Glance cobalt, 57 
 
 Glass jet, 43 
 
 of borax, 90 
 
 of metaphosphate of soda, 
 108 
 
 rod, 22 
 
 soluble, 90 
 
 tubes bent, 172 
 
 with carbonate of soda, 
 
 224 
 
 Glauber's salt, 88 
 Glucose identified, 152 
 Glycerin identified, 174 
 Gold, Mosaic, 47 
 
 test for, 240 
 Goulard's extract, 133 
 Granulated zinc, 242 
 Grape-sugar identified, 152 
 Graphite, 123 
 Green acetate of copper, 37 
 
 Brunswick, 38 
 
 carbonate of copper, 37 
 
 flame, 109, 212 
 
 fused mass, 124 
 
 nitric acid, 106 
 
 oxide of chromium, 66 
 
 Scheele's, 37, 45 
 
 solution, 36, 58, 64, 67, 
 84 
 
 vitriol, 55 
 Gray antimony ore, 49 
 
 copper ore, 204 
 Grough saltpetre, 82 
 Gum identified, 155 
 
 British, 155 
 Gun-metal, 204 
 Gunpowder, analysis of, 244 
 Gypsum, 73 
 
 blowpipe test, 213 
 
 HAEMATITE, 54 
 Hartshorn, 79 
 Heating solids in air, 117 
 in bent tube, 118 
 in tubes, 33 
 on platinum foil, 117 
 
 Heavy spar, 69, 125 
 
 blowpipe test, 213 
 Hippuric acid detected, 130 
 
 identified, 136 
 Hydriodate of potash, 85 
 Hydriodic acid detected, 92 
 
 test for, 237 
 
 Hydrobromic acid detected, 96 
 Hydrochloric acid, HC1, 104 
 
 detected, 91 
 
 for testing, 233 
 
 identified, 104 
 
 precipitate, 25 
 
 test for, 237 
 
 Hydrocyanic acid confirmed, 
 100 
 
 detected, 93 
 
 identified, 101 
 
 Hydrodisodic phosphate, 238 
 Hydroferrocyanic acid identified, 
 
 110 
 Hydrofluoric acid detected, 91 
 
 identified, 97 
 Hydrofluosilicic acid for testing, 
 
 2HF.SiF 4 , 233 
 Hydrogen prepared, 43 
 
 tested, 43 
 Hydropotassic metantirnoniate, 
 
 229 
 
 sulphate, 230 
 Hydrosodic carbonate, 87 
 
 for testing, 229 
 
 Hydrosulphate of ammonia, 
 NH 4 HS, 80, 233 
 
 precipitate, 51 
 
 yellow, 80 
 
 Hydrosulphocyanic acid, 101 
 Hydrosulphuric acid, H 2 S, 233 
 
 apparatus, 234 
 
 confirmed, 99 
 
 detected, 91 
 
 for testing, 233 
 
 identified, 99 
 
 in excess, 21 
 
 precipitate, 32 
 
 prepared, 234 
 
 test for, 228 
 
 Hypochlorite of lime, 74 
 Hypochlorites, test /or, 240 
 Hypochlorous acid confirmed, 98 
 
 detected, 93 
 
 Hyposulphite of soda, 89 
 Hyposulphites detected, 91 
 
252 
 
 INDEX. 
 
 ICELAND SPAR, 73 
 1 Impalpable powder, 120 
 Incandescence, 208 
 Incense, odor of, 132 
 Incrustation on charcoal, 192 
 Indigo, action of heat on, 149 
 
 identified, 149 
 
 reduced, 149 
 Ink identified, 135 
 Insoluble substances analyzed, 
 
 116 
 Iodide of arsenic, 46 
 
 of lead, 30 
 
 of mercury, 41 
 
 of potassium for testing, KI, 
 
 235 
 Iodides, blowpipe test, 217 
 
 common, 99 
 
 detected, 91 
 
 test for, 237 
 Iodine confirmed, 98 
 
 detected, 91 
 
 for testing, 235 
 
 free test for, 240 
 
 identified, 98 
 
 by blowpipe, 221 
 
 vapor, 221 
 
 water, 235 
 Iron acetate, 134 
 
 ammonio-citrate, 140 
 
 and quinine citrate, 140 
 
 as an impurity, 210 
 
 bisulphide, 55 
 
 black oxide, 55 
 
 blowpipe test, 208 
 
 carbonate, 56 
 
 cast, identified, 53 
 
 citrate, 140 
 
 common compounds of, 54 
 
 confirmed, 52 
 
 detected, 51 
 
 by blowpipe, 208 
 
 ferrocyanide, 56, 111 
 
 identified, 52 
 
 iodide, 56 
 
 magnetic oxide, 55 
 
 muriate, 56 
 
 perchloride, Fe 2 Cl 6 , 56 
 
 peroxide, 54 
 
 phosphate, 109 
 
 protosulphate, FeS0 4 , 55 
 
 pyrites, 55 
 
 sesquichloride, Fe 2 Cl 6 , 56 
 
 Iron, sesquioxide, 54 
 
 silicate, 56 
 
 slag, 56 
 
 spathic ore of, 56 
 
 specular, 54 
 
 sulphate, FeS0 4 , 55 
 
 action of heat on, 210 
 
 sulphide, 55 
 
 sulphuret, 55 
 
 tannate, 135 
 
 test for, 52, 229, 233 
 
 tinned. 207 
 
 wire for blowpipe analysis, 
 226 
 
 wrought, identified, 53 
 Ivory black, 123 
 
 JET for burning gases. 43 
 Joints for apparatus, 168 
 
 KAOLIN, 127 
 Kaolinite, 127 
 Kryolite, 97 
 
 identified, 97 
 
 T ACTIC acid identified, 174 
 L Lactide, 174 
 Lactine identified, 153 
 Lamp-black identified, 123 
 Lamps, 94 
 Lead, 28, 204 
 
 acetate, PhCC-J^O.^, 29 
 for testing, 228 
 
 alloys, 205 
 
 binoxide, 29 
 
 blowpipe test, 201 
 
 carbonate, 29 
 
 chloride, 30 
 
 chromate, 29 
 
 common compounds of, 28 
 
 confirmed, 27 
 
 detected, 25, 32 
 
 extracted from galena, 204 
 
 identified, 28 
 
 iodide, 30 
 
 nitrate, 30 
 
 ore, 204 
 
 oxide, 28 
 
 oxychloride, 30 
 
 peroxide, 29 
 
 phosphate, 110 
 
 precipitated by sulphuric 
 acid, 27 
 
INDEX. 
 
 253 
 
 Lead, red oxide, 29 
 
 sugar of, 29 
 
 sulphate, 30 
 
 sulphide, 30 
 
 sulphide in blowpipe analy- 
 sis, 204 
 
 tartrate, 138 
 
 test for, 235 
 
 tested for copper, 206 
 
 tested for silver, 205 
 
 tribasic acetate, 133 
 
 white, 29 
 
 Lemons, essential salt of, 85 
 Levigatioii in blowpipe analysis, 
 
 193 
 
 Liebig's condenser, 168 
 Lime, CaO, 72 
 
 blowpipe test, 212 
 
 borate, 113 
 
 carbonate, 72 
 
 chloride, 74 
 
 citrate, 141 
 
 detected, 68 
 
 hydrate, CaO.H 2 0, 72 
 
 hypochlorite, 74 
 
 oxalate, 65, 74 
 
 phosphate, 64 
 
 blowpipe test. 226 
 detected, 51 
 
 slaked, 72 
 
 sulphate, CaS0 4 , 73 
 blowpipe test, 213 
 
 superphosphate, 64 
 
 tartrate, 137 
 
 water, CaO.H 2 0, 72 
 Limestone, 73 
 Liquids, unknown, examined, 
 
 181 
 
 Liquor ammonice, 79 
 Liquor potassfe, 83 
 Litharge, 28 
 Lithates, 142 
 Lithic acid identified, 141 
 Lunar caustic, 26 
 
 MAGNESIA, 24 
 ammonia phosphate, 65 
 basic carbonate, 24 
 calcined, 24 
 carbonate, 24 
 citrate, 141 
 
 granulated, 141 
 common compounds of, 23 
 
 Magnesia detected, 17 
 
 phosphate, 65 
 
 precipitated by ammonia, 23 
 
 silicate, 128 
 
 sulphate, MgS0 4 , 24 
 Magiiesian limestone, 73 
 Magnesia sulphate, 24, 240 
 Magnesite, 24 
 Magnesium blowpipe test, 190 
 
 common compounds of, 23 
 
 detected, 17 
 
 identified, 23 
 Malachite, 37 
 Malseic acid, 141 
 Mallic acid detected, 130 
 
 identified, 141 
 Malleability tested, "192 
 Manganate of potash, 64 
 
 Manganese, 62 
 
 binoxide, Mn0 2 , 63 
 
 black, 63 
 
 blowpipe test, 208 
 
 common compounds of, 63 
 
 confirmed, 62 
 
 by blowpipe, 209 
 
 detected, 51 
 
 ore, 63 
 
 oxide, 63 
 
 sulphate, MnS0 4 , 63 
 test for, 239 
 
 Manganous sulphate, 63, 240 
 Marble, 73 
 
 Marsh's test for arsenic, 42 
 Massicot, 28 
 
 M.B. examination, organic sub- 
 stances for, 183 
 Meconic acid detected, 130 
 
 identified, 135 
 ; Meerschaum, 128 
 Melting-point determined, 157 
 Mercuric chloride, HgCl 2 , 41, 238 
 
 compounds, 40 
 
 cyanide, 41 
 
 iodide, 41 
 
 oxide, 41 
 
 sulphide, 41 
 Mercurous chloride, 27 
 
 compounds, 27 
 
 nitrate, 27 
 Mercury, 27 
 
 acetate, 133 
 
 bichloride, HgCl,,, 41 
 
 blowpipe test, 190 
 
254 
 
 INDEX. 
 
 Mercury, chloride, HgCI 2 , 41 
 
 common compounds of, 27, 
 40 
 
 confirmed, 40 
 
 cyanide, 41 
 
 detected, 25, 32 
 
 fulminate, 101 
 
 iodide, 41 
 
 nitric oxide, 41 
 
 oxide, 41 
 
 perchloride, HgCl 2 , 41 
 
 protochloride, 27 
 
 protonitrate, 27 
 
 red oxide, 41 
 
 subchloride, 27 
 
 sulphide, 41 
 
 test for, 240 
 
 Metals detected by blowpipe, 190 
 by borax beads, 208 
 by colored flames, 212 
 Metaphosphoric acid, 107 
 Methylated finish, 228 
 
 spirit, 162 
 
 Methylic alcohol identified, 62 
 Microcosmic salt, 108 
 bead, 218 
 for testing, 236 
 
 Milkiness with water, 29, 38, 49 
 Milk-sugar identified, 153 
 Millon's test, 160 
 Mine tin ore, 125 
 Minium, 29 
 
 Molybdate of ammonia for test- 
 ing, 236 
 
 Molybdate of ammonia test, 107 
 Morphine, acetate, 146 
 
 detected, 144 
 
 hydrochlorate, 146 
 
 identified, 145 
 
 meconate, 145 
 
 muriate, 146 
 Mortar, 118 
 Mosaic gold, 47 
 Murexide test for uric acid, 131 
 
 VTAPHTHALINE identified, 158 
 li Narcotine detected, 144 
 
 identified, 147 
 Needle-like crystals, 28 
 Nickel, 57 
 
 blowpipe test, 208 
 
 confirmed, 57 
 
 by blowpipe, 211 
 
 Nickel detected, 51 
 
 ores, 212 
 
 oxide, 58 
 
 speiss, 212 
 
 sulphate, 58 
 
 test for, 229, 239 
 Nicotine, identified, 163 
 Nitrate, mercurous, 27 
 Nitrate of baryta, BaCNOg).,, 236 
 
 of bismuth, 39 
 
 of cobalt, Co(N0 3 ) 2 , 236 
 
 of lead, 30 
 
 of potash for testing, KN0 3 , 
 236 
 
 of silver, AgN0 3 , 26 
 for testing, 236 
 Nitrates, action of heat on, 222 
 
 blowpipe test, 217 
 
 on charcoal, 223 
 Nitre, KN0 3 , 81 
 
 blowpipe test, 219 
 
 cubic, 88 
 Nitric acid, HN0 3 , 105 
 
 confirmed, 105 
 
 detected, 92 
 
 for testing, 237 
 
 identified, 105 
 Nitrites detected, 105 
 Nitrobenzole, 166 
 Nitroprusside of sodium, 237 
 
 for testing, 237 
 Nitrous acid, commercial, 106 
 
 detected, 105 
 Non-metals detected, 91 
 
 OCCLUSION of oxygen by silver, 
 206 
 
 Octahedra of arsenious acid, 42 
 Odors of organic acids, 132 
 Oil of bitter almonds, 166 
 vitriol, 102 
 
 identified, 102 
 Oleic acid, 174 
 Oleine, 174 
 Orange chrome, 29 
 Organic acid detected in alkaline 
 
 solution, 131 
 detected in aqueous 
 
 solution, 130 
 detected in insoluble 
 
 substance, 131 
 acids detected, 130 
 
 by odor, 132 
 
INDEX. 
 
 255 
 
 Organic acids, salts of, analyzed, 
 
 132 
 
 bases identified, 144 
 liquids miscible with potash, 
 
 164 
 
 with water, 162 
 not miscible with hydro- 
 chloric acid, potash, 
 or water, 165 
 matter detected, 96 
 solids tested, 149 
 substances denned, 96 
 substances, acid, 179 
 bitter, 179 
 dissolved by alcohol, 
 
 156 
 dissolved by boiling 
 
 water, 154 
 dissolved by cold water, 
 
 152 
 
 dissolved by ether, 158 
 evolving ammonia, 177 
 for M.B. examination, 
 
 183 
 
 fusible, 177 
 identified, 149 
 insoluble, 159 
 
 in boiling water, 
 
 179 
 
 in cold water, 178 
 liquid, 161 
 nitrogenized, 177 
 soluble in potash, 185 
 sweet, 186 
 unknown examination, 
 
 176 
 
 volatile, 177 
 Original solution, 17 
 Orpiment, 46 
 
 Orthophosphoric acid, 107 
 Oxalate of ammonia (NH 4 ). 2 C 2 4 , 
 
 237 
 
 of lime, 65, 74 
 Oxalic acid confirmed, 111 
 detected, 92 
 identified, 111 
 Oxidizing flame, 191 
 Oxygen evolved, 82 
 
 PALMITIC acid identified, 157 
 Palmitine identified, 158 
 Paraffine identified, 159 
 Peacock ore, 203 
 
 Pearlash, 82 
 
 Pearl white, 39 
 
 Perchloride of iron, Fe 2 Cl 6 , 237 
 
 mercury, HgCl 2 , 238 
 Perforated corks, 171 
 Permanganate of potash, KMn0 4 , 
 
 63 
 
 Peruvian saltpetre, 88 
 Pestle arid mortar. 118 
 Pewter, 205 
 
 Phenic acid identified, 150 
 Phenole identified, 150 
 Phosphate of lime detected, 64 
 of magnesia, 65 
 of magnesia and ammonia, 
 
 65, 109 
 
 of soda, Na 2 HP0 4 , 89 
 and ammonia, 108 
 for testing, 238 
 Phosphates, 10 3 
 
 blowpipe test, 226 
 Phosphorescence, 65 
 Phosphoric acid, blowpipe test, 
 
 226 
 
 confirmed, 106 
 detected, 92 
 identified, 107 
 test for, 107 
 tribasic, 107 
 
 Phosphorus, amorphous, identi- 
 fied, 108 
 salt, 108 
 
 vitreous, identified, 107 
 Picric acid identified, 149 
 Pig-iron identified, 53 
 Pineapple odor, 164 
 Pink salt, 48 
 solution, 57 
 
 sulphate of manganese, 63 
 Pipe-clay, 127 
 Plaster of Paris, 73 
 Platina, muriate, 229 
 Platinic chloride, PtCl 4 , 229 
 Platinum, bichloride, PtCl 4 , 229 
 capsule, 121 
 chloride, PtCl 4 , 229 
 corroded, 125 
 foil, 120 
 
 for fusing, 120 
 test for, 231, 240 
 wire cleaned, 195 
 
 for borax beads, 194 
 colored flames, 78 
 
Plumbago, 123 
 Plumbic acetate, 228 
 Porcelain, 127 
 Potash, KHO, 83 
 
 acetate, 134 
 
 alum, 59 
 
 antinioniate, KSb0 3 , 50 
 
 bicarbonate, 83 
 
 bichromate, K 2 0,2Cr0 3 , 67 
 
 binoxalate, 85 
 
 bisulphate, KHS0 4 , 83 
 blowpipe test, 217 
 
 bitartrate, 83, 138 
 
 blowpipe test, 222 
 
 carbonate, 82 
 
 caustic, 83 
 
 chlorate, 82 
 
 chromate, 67 
 
 common compounds of, 81 
 
 for testing, KHO, 238 
 
 hydrate, 83 
 
 hydriodate, 85 
 
 rnaiiganate, 64 
 
 nitrate, KN0 3 , 81 
 
 oleate, 85 
 
 oxalate, 85 
 
 permanganate, KMn0 4 , 63 
 
 prussiate, 84 
 
 red prussiate, 84 
 
 silicate, 85 
 
 solution of, KHO, 83 
 
 sulphate, 83 
 Potashes, American, 82 
 Potassafusa, 83 
 Potassic cyanide, KCN, 84, 232 j 
 
 dichromate, 67, 229 
 
 ferridcyanide, 84, 232 
 
 ferrocyanide, 84, 232 
 
 hydrate, KHO, 83, 238 
 
 iodide, KI, 85, 235 
 
 nitrate, KN0 3 , 81, 236 
 Potassium, 81 
 
 blowpipe test, 212 
 
 carbonate, 82 
 
 chloride, 83 
 
 common compounds of, 81 
 
 cyanide, KCN, 84, 232 
 
 detected, 77 
 
 ferridcyanide, K 3 FeCy 6 , 84, 
 232 
 
 ferrocyanide, K 4 FeCy 6 , 84, 
 
 232 
 blowpipe test, 214 
 
 Potassium, iodide, KI, 85 
 
 nitrate, KN0 3 , 81 
 
 sulphate, 83 
 
 sulphide, 99 
 
 sulphocyanide, 101 
 Powdering substances, 118 
 Precipitate defined, 17 
 
 washed, 33 
 
 white, 41 
 
 Precipitation promoted by stir- 
 ring, 22, 78 
 Prepared chalk, 73 
 Preston salts, 80 
 Protochloride of tin for testing, 
 
 SnCl 2 , 239 
 
 Protosulphate of iron, FeS0 4 , 240 
 Prussian blue, 52, 56, 111 
 
 test, 100 
 
 Prussiate of potash, 84 
 Prussic acid, 101 
 
 detected, 93 
 
 identified, 101 
 Pulverization, 118 
 Pumice-stone, 128 
 Purple crystals, 67 
 
 solution, 63 
 
 vapors, 27, 94 
 Putty powders, 12f> 
 Pyrites, 55 
 
 copper, 203 
 
 iron, 55 
 
 Pyrogallic acid identified, 153 
 Pyrogalline, 153 
 Pyroligneous acid, 133 
 
 ether, 162 
 Pyrolusite, 63 
 Pyroxylic spirit, 162 
 
 QUARTZ, 126 
 Quicklime, 72 
 Quicksilver, 27 
 Quinine and iron citrate, 140 
 detected, 144 
 identified, 147 
 sulphate, 147 
 
 RAIN-WATER, 242 
 Rat's-tail file, 171 
 Reagents, 228 
 Realgar, 46 
 
 Red chlorosulphide of lead, 32 
 chromate of lead, 29 
 chromate of potash, 67 
 
INDEX. 
 
 257 
 
 Red color with sulphuric acid, 
 154 
 
 drops, 221 
 
 flame, 71, 212 
 
 haematite, 54 
 
 iodide of arsenic, 46 
 
 iodide of mercury, 41 
 
 lead, 29 
 
 litmus paper, 235 
 
 mordant, 60 
 
 nitroprusside of sodium, 237 
 
 orpiment, 46 
 
 oxide of copper, 38 
 iron, 54 
 lead, 29 
 mercury, 41 
 
 phosphorus, 108 
 
 precipitate, 41 
 
 prussiate of potash, 84 
 
 solution, 63, 67, 134 
 
 sulphide of antimony, 49 
 mercury, 41 
 
 vapors, 91, 103 
 Reducing flame. 191 
 Reduction of metals on charcoal, 
 
 191 
 
 Reinsch's test for arsenic, 42 
 Retort, 168 
 Retort stand, 94 
 Ring gas-burner, 169 
 Roasting before blowpipe, 203 
 Rochelle salt, 139 
 Rod, breaking and rounding, 22 
 Roll brimstone, 122 
 Rose gas-burner, 169 
 Rosin identified, 157 
 Rouge, jeweller's, 55 
 Rust, 55 
 
 SAL-AMMONIAC, 79 
 Salicine detected in quinine, 
 147 
 
 identified, 154 
 Saliretine, 154 
 Sal prunella, 82 
 Salt, 88 
 
 cake, 88 
 
 common, 88 
 
 of lemon, 85 
 
 of sorrel, 85 
 
 of tartar, 82 
 Saltpetre, 81 
 
 flour, 82 
 
 Saltpetre, Peruvian, 88 
 
 Sand, 126 
 
 Scheele's green, 37, 45 
 
 Selenite, 73 
 
 Shrapnel bullets, 205 
 
 Sifting, 119 
 
 Silica, 126 
 
 amorphous, 126 
 
 detected, 113 
 
 by blowpipe, 224 
 
 soluble, 126 
 Silicic acid, 126 
 
 detected, 113 
 
 by blowpipe, 224 
 
 separation from solutions, 
 
 113 
 Silicates, common simple, 127 
 
 detected, 113 
 
 on charcoal, 223 
 
 soluble, 114 
 | Silicium, 126 
 i Silicofluoric acid, 233 
 Silicon, 126 
 
 fluoride, 97 
 
 oxide, 126 
 Silver acetate, 133 
 
 blowpipe test, 201, 206 
 
 chloride, 26, 103, 124 
 
 in blowpipe analysis, 
 206 
 
 common compounds of, 26 
 
 cyanide, 103 
 
 detected, 25 
 
 extracted from lead, 205 
 Silver ferridcyanide, 110 
 
 ferrocyanide, 110 
 
 identified, 26 
 
 nitrate, AgN0 3 , 26 
 
 oxalate, 112 
 
 precipitates distinguished, 
 103 
 
 test for, 235 
 
 tested for copper, 206 
 Singed hair, odor of, 132 
 Slag, iron, 56 
 Slaked lime, 72 
 Slate, 127 
 Smalt, 57 
 Smelling salts, 80 
 Smell of almonds, 132, 166 
 
 burnt sugar, 137 
 
 chlorine, 74 
 
 gas, 158, 166 
 
 09* 
 
258 
 
 INDEX. 
 
 Smell of incense, 136 
 singed hair, 132 
 tar, 164 
 Soap, 90 
 
 soda, 90 
 soft, 85 
 
 Soap-stone, 128 
 Soda, acetate, 134 
 aluminate, 60 
 arseniate, 46 
 ash, 88 
 bibprate, Na 2 0.2B 2 3 , 89 
 
 blowpipe test, 226 
 bicarbonate, NaHCO 3 , 87 
 carbonate, Na. 2 C0 3 , 87 
 dried, 230 
 for blowpipe analysis, 
 
 193 
 
 caustic, 88 
 chloride, 89 
 crystals, 87 
 hydrate, 88 
 hyposulphite, 89 
 
 blowpipe test, 215 
 nitrate, 88 
 
 blowpipe test, 215 
 orthophosphate, 89 
 phosphate, Na 2 HP0 4 , 89 
 silicate, 90 
 stannate, 47 
 sulphate, 88 
 sulphite, 89 
 tungstate, 90 
 urate, 142 
 waste, 100 
 
 Sodic carbonate, 87, 230 
 Sodium, blowpipe test, 212 
 carbonate, 87 
 chloride, 88 
 
 common compounds of, 87 
 detected, 77 
 flame deceptive, 214 
 hyposulphite, 89 
 jmpurity, 214 
 'nitrate, 88 
 phosphate, 89 
 sulphate, 88 
 sulphite, 89 
 Soft soap, 85 
 Solder, 205 
 
 Solid unknown substances ex- 
 amined, 181 
 Soluble glass, 90 
 
 Solution, 19 
 Soot identified, 124 
 Spathic iron ore, 56 
 Spatula, 118 
 Specular iron pre, 54 
 Speiss, 212 
 Spelter (zinc), 60 
 Spermaceti identified, 159 
 Spirit-black, 123 
 Spirit-blowpipe, 173 
 Spirit-lamp, 19 
 Spirit of wine, 162 
 Spirting, prevention of, 94 
 Spongy flakes of sulphur, 41 
 Stannate of soda, 47 
 Stannic acid, 47, 125 
 
 chloride, 48 
 
 compounds, 47 
 
 Stannous chloride, SnCL, 36, 
 234 
 
 compounds, 36 
 Starch for testing, 240 
 
 identified, 154 
 
 sugar, 152 
 
 test for, 235 
 
 Steam-bath for evaporation, 174 
 Stearic acid identified, 157 
 Stearine identified, 156 
 Steatite, 128 
 Steel identified, 53 
 Stirring, 22 
 
 rod, 22 
 
 to promote precipitation, 22, 
 
 78 
 
 Stoppers, India-rubber, 172 
 Stourbridge clay, 127 
 Stream tin ore, 125 
 Strong sulphuric acid, H 2 S0 4 , 241 
 Strontia, carbonate, 71 
 
 detected, 68 
 
 nitrate, 71 
 
 sulphate, 125 
 Strontianite, 71 
 Strontium, 70 
 
 blowpipe test, 212 
 
 confirmed, 70 
 
 detected, 68 
 Strychnine detected, 144 
 
 identified, 146 
 Sublimate corrosive, 41 
 Sublimation, J36 
 Succinic acid detected, 130 
 
 identified, 13C 
 
INDEX. 
 
 259 
 
 Sugar, 152 
 
 copper test for, 152 
 
 identified, 152 
 
 of lead, 29 
 
 Sulphate of copper, CuS0 4 , 37 
 for testing, 240 
 
 of iron for testing, FeS0 4 , 240 
 
 lead, 30 
 
 of lime for testing, CaS0 4 , 
 240 
 
 of niagnesia, MgS0 4 , 24 
 for testing, 240 
 
 of manganese for testing, 
 MnSO 4 , 240 
 
 of zinc, 61 
 Sulphates, action of heat on, 221 
 
 blowpipe test, 224 
 
 detected, 92 
 
 impurities, 102 
 
 insoluble, 125 
 Sulphide of ammonium, (NH 4 ) 2 S, 
 
 80 
 for testing,, 233 
 
 of ammonium precipitate, 51 
 
 of antimony, 49 
 
 of arsenic, 46 
 
 of copper, 38 
 
 of iron, 55 
 
 of lead, 30 
 
 of tin, 36 
 
 of zinc, 61 
 Sulphides, action of heat on, 222 
 
 common, 99 
 
 detected, 91 
 
 by blowpipe, 225 
 
 on charcoal, 223 
 Sulphites detected, 91 
 Sulphocyanides detected, 92 
 
 test for. 241 
 Sulphur, 122 
 
 blowpipe test, 222 
 
 crude, 122 
 
 detected, 91 
 
 by blowpipe, 222 
 
 distilled, 122 
 
 evolved, 222 
 
 expelled by roasting, 203 
 
 flowers of. 122 
 
 identified, 122 
 
 insoluble, 122 
 
 milk of, 122 
 
 precipitated, 122 
 
 precipitation of, 23 
 
 Sulphur roll, 122 
 Sicilian, 122 
 soluble, 122 
 sublimed, 122 
 viscous, 122 
 
 Sulphurets, common, 99 
 Sulphuretted hydrogen appara- 
 tus, 234 
 
 identified, 98 
 
 precipitate, 32 
 
 prepared, 233 
 
 test for, 228 
 Sulphuric acid, H 2 S0 4 , 102 
 
 blowpipe test, 224 
 
 detected, 92 
 
 for testing, 241 
 
 identified, 102 
 
 Nordhausen, 102 
 
 test for, 236 
 Sulphurous acid confirmed, 101 
 
 detected, 91 
 
 evolved, 223 
 
 Sulphydrate of ammonium, 233 
 Superphosphate of Hme, t>4 
 Sweet substances, 1*86 
 Sweet taste, 29 
 Sylvic acid, 158 
 
 'TABLE A, page 17 
 
 1 
 
 B, 
 C, 
 
 F, 
 
 G, 
 
 L, 
 
 M, 
 N, 
 
 0, 
 P, 
 
 Q, 
 R, 
 
 B, 
 T, 
 U, 
 V, 
 
 w, 
 
 x , 
 Y, 
 
 25 
 
 32 
 
 51 
 
 68 
 
 77 
 
 91 
 
 92, 93 
 116 
 129 
 130 
 131 
 131 
 144 
 151 
 161 
 190 
 201 
 208 
 212 
 216 
 217 
 221 
 223 
 224 
 
INDEX. 
 
 Taiinic acid detected, 130 
 identified, 135 
 test for, 238 
 Tannin, 135 
 Tartar, cream of, 83 
 emetic, 49 
 
 blowpipe test, 202 
 salt of, 82 
 
 Tartaric acid, H 2 C 4 H 4 6 , 137 
 detected, 130 
 for testing, 241 
 identified, 137 
 Tartrates, action of heat on, 222 
 
 common, 138 
 Test papers, 235, 241 
 
 use of, 34 
 tube, 19 
 
 rack, 19 
 Tests, 228 
 
 addition of, 21 
 Theine detected, 145 
 
 identified, 145 
 Thermometer, 168 
 Tin, 35 
 
 alloys of, 205 
 before blowpipe, 207 
 bichloride, 48 
 bichloride with hydrochlo- 
 
 rate of ammonia, 48 
 binoxide, 47, 125 
 bisulphide, 47 
 blowpipe test, 201 
 common compounds of, 36, 
 
 47 
 
 confirmed, 35, 46 
 crystals, 36 
 detected, 32 
 
 by blowpipe, 201 
 foil, 239 
 granulated, 239 
 identified, 35 
 
 in insoluble substances, 125 
 nitromuriate, 48 
 ore, 125 
 persalts of, 47 
 plate, 207 
 
 protochloride, SnCl 2 , 36 
 protosalts of, 36 
 protosulphide, 36 
 pyrites, 36 
 
 reduction on charcoal, 190 
 salts of, 36, 47 
 stone, 125 
 
 Tin test for, 238 
 
 Tincture of iron, 56 
 
 Toluidine, 164 
 
 Tongs, 117 
 
 Triangle, 117 
 
 Triple phosphate, 65, 109 
 
 Tube, blowpipe test in, 221 
 
 funnel, 170 
 
 German, 33 
 Tubes, bent, 172 
 
 sealed, 33 
 
 Tubulated retort, 168 
 Tubulus, 168 
 Tungstate of soda, blowpipe test, 
 
 215 
 
 Tungstic acid detected, 90 
 Turmeric, 241 
 
 paper, 241 
 Type-metal, 205 
 
 TTLTRAMARINE, 100 
 U University of London ex- 
 amination, 183 
 Unknown liquid examined, 181 
 
 solid examined, 181 
 Urates, common, 142 
 Urea identified, 153 
 nitrate, 155 
 oxalate, 155 
 Uric acid confirmed, 141 
 detected, 131 
 identified, 141 
 
 VALERIANIC acid, 164 
 Verdigris, 37 
 Vermilion, 41 
 
 antimony, 49 
 Vinegar, 133 
 Violet flame, 81 
 Vitriol, blue, 37 
 
 green, 55 
 
 identified, 102 
 
 white, 61 
 
 w 
 
 CASHING bottle, 33 
 precipitates, 33 
 
 Washing-soda, 87 
 Water, H 2 0, 181 
 Water-bath, 174 
 Water for testing, 241 
 
 glass, 90 
 
 purification, 242 
 
 tested for impurities, 242 
 
INDEX. 
 
 201 
 
 Wax, identified, 159 
 White lead, 29 
 
 precipitate, 41 
 
 vitriol, 61 
 Wire triangle, 117 
 Witherite, 69 
 Wood-charcoal, 123 
 Wood-naphtha, 162 
 Wood-spirit, 163 
 
 YELLOW chromate of baryta, 
 70 
 
 of potash, 67 
 chrome, 29 
 ' flame, 212 
 fused mass, 124 
 iodide of lead, 30 
 
 of mercury, 41 
 orpiment, 46 
 oxide of lead, 28 
 oxychloride of lead, 30 
 picric acid, 149 
 
 Yellow prussiate of potash, 84 
 sulphide of tin, 47 
 
 ZEOLITES, 114 
 Zeolitic minerals, 114 
 Zinc before blowpipe, 208 
 blowpipe test, 190 
 carbonate, 61 
 chloride, 62 
 
 common compounds of, 61 
 confirmed, 60 
 detected, 51 
 glance, 128 
 granulated, 43 
 identified, 60 
 lactate, 174 
 oxide, 61 
 silicate, 128 
 sulphate, 61 
 sulphide, 61 
 test for, 235 
 white, 61 
 
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 Practitioner in the country. In our estimation, it is the best book 
 of the kind ever written." N. Y. Medical Journal. 
 
 No. 8. MEDICAL, JURISPRUDENCE AND 
 TOXICOLOG-Y. New Ed. 
 
 By John J. Reese, M.D., Professor of Medical Jurispru- 
 dence and Toxicology in the University of Pennsyl- 
 vania ; President of the Medical Jurisprudence Society 
 of Phila. ; 2d Edition, Revised and Enlarged. 
 
 "This admirable text-book." Amer.Jour. of Med. Sciences. 
 
 " We lay this volume aside, after a careful perusal of its pages, 
 with the profound impression that it should be in the hands of every 
 
 doctor and lawyer. It fully meets the wants of all students 
 
 He has succeeded in admirably condensing into a handy volume all 
 the essential points." Cincinnati Lancet and Clinic. 
 
 No. 9. ORGANIC CHEMISTRY. 
 
 Or the Chemistry of the Carbon Compounds. By Prof. 
 VICTOR VON RICHTER, University of Breslau. Au- 
 thorized translation, from the Fourth German Edition. 
 By EDGAR F. SMITH, M.A., PH.D. ; Prof, of Chemistry 
 in University of Pennsylvania; Member of the Chem. 
 Socs. of Berlin and Paris. 
 
 " I must say that this standard treatise is here presented in a 
 remarkably compendious shape." J. W. Holland, ni-D., Professor 
 of Chemistry, Jefferson Medical College, Philadelphia. 
 
 " This work brings the whole matter, in simple, plain language, 
 to the student in a clear, comprehensive manner. The whole 
 method of the work is one that is- more readily grasped than that of 
 older and more famed text-books, and we look forward to the time 
 when, to a great extent, this work will supersede others, on the 
 score of its better adaptation to the wants of both teacher and 
 student." Pharmaceutical Record. 
 
 Price of each Book, Cloth, $3.00 ; Leather, $3.50. 
 
6 STUDENTS' TEXT-BOOKS AND MANUALS. 
 
 ANATOMY. 
 
 Holden's Anatomy. A manual of Dissection of the Human 
 Body. Fifth Edition. Enlarged, with Marginal References and 
 over 200 Illustrations. Octavo; Cloth, 5.00; Leather, 6.00 
 
 Bound in Oilcloth, for the Dissecting Room, $4.50. 
 
 " No student of Anatomy can take up this book without being 
 pleased and instructed. Its Diagrams are original, striking and 
 suggestive, giving more at a glance than pages of text description. 
 * * * The text matches the illustrations in directness of prac- 
 tical application and clearness of detail." New York Medical 
 Record. 
 
 Holden's Human Osteology. Comprising a Description of the 
 Bones, with Colored Delineations of the Attachments of the 
 Muscles. The General and Microscopical Structure of Bone and 
 its Development. With Lithographic Plates and Numerous Illus- 
 trations. Seventh Edition. 8vo. Cloth, 6.00 
 
 Holden's Landmarks, Medical and Surgical. 4th ed. 
 
 Cloth, 1.25 
 
 Heath's Practical Anatomy. Sixth London Edition. 24 Col- 
 ored Plates, and nearly 300 other Illustrations. Cloth, 5.00 
 
 Potter's Compend of Anatomy. Fourth Edition. 117 Illus- 
 trations. Cloth, i.oo; Interleaved for Notes, 1.25 
 
 CHEMISTRY. 
 
 Hartley's Medical Chemistry. A text-book prepared specially 
 for Medical, Pharmaceutical and Dental Students. With 40 
 Illustrations, Plate of Absorption Spectra and Glossary of Chemi- 
 cal Terms. Cloth, 2.50 
 *** This book has been written especially for students and phy- 
 sicians. It is practical and concise, dealing only with those parts 
 of chemistry pertaining to medicine ; no time being wasted in long 
 descriptions of substances and theories of interest only to the 
 advanced chemical student. 
 
 Bloxam's Chemistry, Inorganic and Organic, with Experiments. 
 Sixth Edition. Enlarged and Rewritten. Nearly 300 Illus- 
 trations. Cloth, 4.50 ; Leather, 5.50 
 
 Richter's Inorganic Chemistry. A text-book for Students. 
 Third American, from Fifth German Edition. Translated by 
 Prof. Edgar F. Smith, PH.D. 89 Wood Engravings and Colored 
 Plate of Spectra. Cloth, 2.00 
 
 Richter's Organic Chemistry, or Chemistry of the Carbon 
 Compounds. Translated by Prof. Edgar F. Smith, PH.D. 
 Illustrated. Cloth, 3.00; Leather, 3.50 
 
 ee pages 2 to j for list of Students' Manuals. 
 
STUDENTS' TEXT-BOOKS AND MANUALS. 7 
 
 Chemistry : Continued. 
 
 Trimble. Practical and Analytical Chemistry. A Course in 
 Chemical Analysis, by Henry Trimble, Prof, of Analytical Chem- 
 istry in the Phila. College of Pharmacy. Illustrated. Second 
 Edition. 8vo. Cloth, 1.50 
 
 Tidy. Modern Chemistry. 2d Ed. Cloth, 5.50 
 
 Leffmann's Compend of Chemistry. Inorganic and Organic. 
 Including Urinary Analysis and the Sanitary Examination of 
 Water. New Edition. Cloth, i.oo; Interleaved for Notes, 1.25 
 
 Muter. Practical and Analytical Chemistry. Second Edi- 
 tion. Revised and Illustrated. Cloth, 2.00 
 
 Holland. The Urine, Common Poisons, and Milk Analysis, 
 Chemical and Microscopical. For Laboratory Use. sd 
 Edition, Enlarged. Illustrated. In Press. 
 
 Van Niiys. Urine Analysis. Illus. Cloth, 2.00 
 
 Wolff's Applied Medical Chemistry. By Lawrence Wolff, 
 M.D., Demonstrator of Chemistry in Jefferson Medical College, 
 Philadelphia. Cloth, i.oo 
 
 CHILDREN. 
 
 Goodhart and Starr. The Diseases of Children. A Manual 
 for Students and Physicians. By J. F. Goodhart, M.D., Physi- 
 cian to the Evelina Hospital for Children ; Assistant Physician 
 to Guy's Hospital, London. American Edition, Revised and 
 Edited by Louis Starr, M.D., Clinical Professor of Diseases of 
 Children in the Hospital of the University of Pennsylvania; 
 Physician to the Children's Hospital, Philadelphia. Containing 
 many new Prescriptions, a List of over 50 Formulae, conforming 
 to the U. S. Pharmacopoeia, and Directions for making Arti- 
 ficial Human Milk, for the Artificial Digestion of Milk, etc. 
 
 Cloth, 3.00; Leather, 3.50 
 
 Day. On Children. A Practical and Systematic Treatise. 
 Second Edition. 8vo. 752 pages. Cloth, 3.00; Leather, 4.00 
 
 Meigs and Pepper. The Diseases of Children. Seventh 
 Edition. 8vo. Cloth, 5.00; Leather, 6.00 
 
 Starr. Diseases of the Digestive Organs in Infancy and 
 Childhood. With chapters on the Investigation of Disease, 
 and on the General Management of Children. By Louis Starr, 
 M.D., Clinical Professor of Diseases of Children in the Univer- 
 sity of Pennsylvania; with a section on Feeding, including special 
 Diet Lists, etc. Illus. Cloth, 2.50 
 
 49- See pages 13 and ib for list of f Quiz- Compends f 
 
8 STUDENTS' TEXT-BOOKS AND MANUALS. 
 
 DENTISTRY. 
 
 Fillebrown. Operative Dentistry. 330 Illustrations. Just 
 Ready. Cloth, 2.50 
 
 Flagg's Plastics and Plastic Filling. 3d Ed. Preparing. 
 
 Gorgas. Dental Medicine. A Manual of Materia Medica and 
 Therapeutics. Third Edition. Cloth, 3.25 
 
 Harris. Principles and Practice of Dentistry. Including 
 Anatomy, Physiology, Pathology, Therapeutics, Dental Surgery 
 and Mechanism. Twelfth Edition. Revised and enlarged by 
 Professor Gorgas. 1028 Illustrations. Cloth, 7.00 ; Leather, 8.00 
 
 Richardson's Mechanical Dentistry. Fifth Edition. 569 
 Illustrations. 8vo. Cloth, 4.50; Leather, 5.50 
 
 Stocken's Dental Materia Medica. Third Edition. Cloth, 2.50 
 
 Taft's Operative Dentistry. Dental Students and Practitioners. 
 Fourth Edition. 100 Illustrations. Cloth, 4.25 ; Leather, 5.00 
 
 Talbot. Irregularities of the Teeth, and their Treatment. 
 Illustrated. 8vo. Cloth, 2.00 
 
 Tomes' Dental Anatomy. Third Ed. 191 Illus. Preparing. 
 
 Tomes' Dental Surgery. 3d Edition. Revised. 292 Illus. 
 772 Pages. Cloth, 5.00 
 
 DICTIONARIES. 
 
 Cleaveland's Pocket Medical Lexicon. Thirty-first Edition. 
 
 Giving correct Pronunciation and Definition of Terms used in 
 
 Medicine and the Collateral Sciences. Very small pocket size. 
 
 Cloth, red edges .75 ; pocket-book style, i.oo 
 
 Longley's Pocket Dictionary. The Student's Medical Lexicon, 
 giving Definition and Pronunciation of all Terms used in Medi- 
 cine, with an Appendix giving Poisons and Their Antidotes, 
 Abbreviations used in Prescriptions, Metric Scale of Doses, etc. 
 24mo. Cloth, i.oo; pocket-book style, 1.25 
 
 EYE. 
 
 Arlt. Diseases of the Eye. Including those of the Conjunc- 
 tiva, Cornea, Sclerotic, Iris and Ciliary Body. By Prof. Von 
 Arlt. Translated by Dr. Lyman Ware. Illus. 8vo. Cloth, 2.50 
 
 Hartridge on Refraction. 3d Ed. Cloth, 2.00 
 
 Macnamara. Diseases of the Eye. 4th Edition. Revised. 
 Colored Plates and Wood Cuts and Test Types. Cloth, 4.00 
 
 Meyer. Diseases of the Eye. A complete Manual for Stu- 
 dents and Physicians. 270 Illustrations and two Colored Plates. 
 8vo. Cloth, 4.50; Leather, 5.50 
 
 Fox and Gould. Compend of Diseases of the Eye and 
 Refraction. 2d Ed. Enlarged. 71 Illus. 39 Formulae. 
 
 Cloth, i.oo ; Interleaved for Notes, 1.25 
 
 JiSr" See pages 2 to 5 for list of Students' Manuals. 
 
STUDENTS' TEXT-BOOKS AND MANUALS. 9 
 
 ELECTRICITY. 
 
 Mason's Compend of Medical and Surgical Electricity. 
 With numerous Illustrations. i2mo. Cloth, i.oo 
 
 HYGIENE. 
 
 Parkes' Practical Hygiene. Seventh Edition, enlarged. Illus- 
 trated. 8vo. Cloth, 4.50 
 Wilson's Handbook of Hygiene and Sanitary Science. 
 
 Sixth Edition. Revised and Illustrated. Cloth, 2.75 
 
 MATERIA MEDICA AND THERAPEUTICS. 
 
 Potter's Compend of Materia Medica, Therapeutics and 
 
 Prescription Writing. Fifth Edition, revised and improved. 
 
 Cloth, i.oo; Interleaved for Notes, 1.25 
 
 Biddle's Materia Medica. Eleventh Edition. By the late 
 John B. Biddle, M.D., Professor of Materia Medica in Jefferson 
 Medical College, Philadelphia. Thoroughly revised, and in many 
 parts rewritten, by his son, Clement Biddle, M.D., Assistant 
 Surgeon, U. S. Navy, assisted by Henry Morris, M.D., Demon- 
 strator of Obstetrics in Jefferson Medical College. 8vo., illus- 
 trated. Cloth, 4.25; Leather, 5.00 
 
 Headland's Action of Medicines, gih Ed. 8vo. Cloth, 3.00 
 
 Potter. Materia Medica, Pharmacy and Therapeutics. 
 Including Action of Medicines, Special Therapeutics, Pharma- 
 cology, etc. Page 4. Cloth, 3.00; Leather, 3.50 
 
 Starr, Walker and Powell. Synopsis of Physiological 
 Action of Medicines, based upon Prof. H. C. Wood's " Materia 
 Medica and Therapeutics." 3d Ed. Enlarged. Cloth, .75 
 
 Waring. Therapeutics. With an Index of Diseases and an 
 Index of Remedies. A Practical Manual. Fourth Edition. 
 Revised and Enlarged. Cloth, 3.00; Leather, 3.50 
 
 MEDICAL JURISPRUDENCE. 
 
 Reese. A Text-book of Medical Jurisprudence and Toxi- 
 cology. By John J. Reese, M.D., Professor of Medical Juris- 
 prudence and Toxicology in the Medical Department of the 
 University of Pennsylvania; President of the Medical Juris- 
 prudence Society of Philadelphia ; Physician to St. Joseph's 
 Hospital ; Corresponding Member of The New York Medico- 
 legal Society. 2d Edition. Cloth, 3.00 ; Leather, 3.50 
 
 Woodman and Tidy's Medical Jurisprudence and Toxi- 
 cology. Chromo-Lithographic Plates and 116 Wood engravings. 
 
 Cloth, 7.50; Leather, 8.50 
 
 J86S" See pages 15 and ib for list of fQuiz-Compends ? 
 
10 STUDENTS' TEXT-BOOKS AND MANUALS. 
 
 MISCELLANEOUS. 
 
 Allingham. Diseases of the Rectum. Fourth Edition. Illus- 
 trated. 8vo. Paper covers, .75; Cloth, 1.25 
 
 Beale. Slight Ailments. Their Nature and Treatment. Illus- 
 trated. 8vo. Paper cover, .75 ; Cloth, 1.25 
 Domville on Nursing. 6th Edition. Cloth, .75 
 
 Fothergill. Diseases of the Heart, and Their Treatment. 
 Second Edition. 8vo. Cloth, 3.50 
 
 Gowers. Diseases of the Nervous System. 341 Illus- 
 trations. Cloth, 6.50 ; Leather, 7.50 
 
 Mann's Manual of Psychological Medicine, and Allied Ner- 
 vous Diseases. Their Diagnosis, Pathology and Treatment, and 
 their Medico-Legal Aspects. Illus. Cloth, 5.00 ; Leather, 6.00 
 
 Tanner. Memoranda of Poisons. Their Antidotes and Tests. 
 Sixth Edition. Revised by Henry Leffmann, M.D. Cloth, .75 
 
 OBSTETRICS AND GYN^COLOGY. 
 
 Byford. Diseases of Women. The Practice of Medicine and 
 Surgery, as applied to the Diseases and Accidents Incident to 
 Women. By W. H. Byford, A.M., M.D., Professor of Gynaecology 
 in Rush Medical College and of Obstetrics in the Woman's Med- 
 ical College, etc., and Henry T. Byford, M.D., Surgeon to the 
 Woman's Hospital of Chicago ; Gynaecologist to St. Luke's 
 Hospital, etc. Fourth Edition. Revised, Rewritten and En- 
 larged. With 306 Illustrations, over 100 of which are original. 
 Octavo. 832 pages. Cloth, 5.00 ; Leather, 6.00 
 
 Cazeaux and Tarnier's Midwifery. With Appendix, by 
 Munde. The Theory and Practice of Obstetrics ; including the 
 Diseases of Pregnancy and Parturition, Obstetrical Operations, 
 etc. By P. Cazeaux. Remodeled and rearranged, with revi- 
 sions and additions, by S. Tarnier, M.D., Professor of Obstetrics 
 and Diseases of Women and Children in the Faculty of Medicine 
 of Paris. Eighth American, from the Eighth French and First 
 Italian Edition. Edited by Robert J. Hess, M.D., Physician tp 
 the Northern Dispensary, Philadelphia, with an appendix by 
 Paul F. Munde, M.D., Professor of Gynaecology at the N. Y. 
 Polyclinic. Illustrated by Chromo- Lithographs, Lithographs, 
 and other Full-page Plates, seven of which are beautifully colored, 
 and numerous Wood Engravings. Students' Edition. One 
 Vol., 8vo. Cloth, 5.00; Leather, 6.00 
 
 Lewers' Diseases of Women. A Practical Text-Book. 139 
 Illustrations. Cloth, 2.25 
 
 Parvin's Winckel's Diseases of Women. Edited by Prof. 
 Theophilus Parvin, Jefferson Medical College, Philadelphia. 
 117 Illustrations. See page 3. Cloth, 3.00; Leather, 3.50 
 
 Morris. Compend of Gynaecology. Illustrated. In Press. 
 %S~ See pages 2 to 5 for list of New Manuals. 
 
STUDENTS' TEXT-BOOKS AND MANUALS. 11 
 
 Obstetrics and Gyncec ology : Continued. 
 
 Winckel's Obstetrics. A Text-book on Midwifery, includ- 
 ing the Diseases of Childbed. By Dr. F. Winckel, Professor 
 of Gynaecology, and Director of the Royal University Clinic for 
 Women, in Munich. Authorized Translation, by J. Clifton 
 Edgar, M.D., Lecturer on Obstetrics, University Medical Col- 
 lege, New York, with nearly 200 handsome illustrations, the 
 majority of which are original with this work. Octavo. In press. 
 
 Landis' Compend of Obstetrics. Illustrated. 4th edition, 
 enlarged. Cloth, i.oo; Interleaved for Notes, 1.25 
 
 Galabin's Midwifery. A New Manual for Students. By A. 
 Lewis Galabin, M.D., F.R.C.P., Obstetric Physician to Guy's 
 Hospital, London, and Professor of Obstetrics in the same Insti- 
 tution. 227 Illustrations. See page 3. Cloth, 3.00; Leather, 3.50 
 
 Glisan's Modern Midwifery. 2d Edition. Cloth, 3.00 
 
 Rigby's Obstetric Memoranda. By Alfred Meadows, M.D. 
 4th Edition. Cloth, .50 
 
 Meadows' Manual of Midwifery. Including the Signs and 
 Symptoms of Pregnancy, Obstetric Operations, Diseases of the 
 Puerperal State, etc. 145 Illustrations. 494 pages. Cloth, 2.00 
 
 Swayne's Obstetric Aphorisms. For the use of Students 
 commencing Midwifery Practice. 8th Ed. i2mo. Cloth, 1.25 
 
 PATHOLOGY. HISTOLOGY. BIOLOGY. 
 
 Bowlby. Surgical Pathology and Morbid Anatomy, for 
 Students. 135 Illustrations. i2mo. Cloth, 2.00 
 
 Davis' Elementary Biology. Illustrated. Cloth, 4.00 
 
 Rindfleisch's General Pathology. By Prot. Edward Rind- 
 fleisch. Translated by Wm. H. Mercur, M.D. Edited by James 
 Tyson, M.D., Professor of Clinical Medicine in the University 
 of Pennsylvania. i2mo. Cloth, 2.00 
 
 Gilliam's Essentials of Pathology. A Handbook for Students. 
 47 Illustrations. i2mo. Cloth, 2.00 
 
 *#*The object of this book is to unfold to the beginner the funda- 
 mentals of pathology in a plain, practical way, and by bringing 
 them within easy comprehension to increase his interest in the study 
 of the subject. 
 
 Gibbes' Practical Histology and Pathology. Third Edition. 
 
 Enlarged. i2mo. Cloth, 1.75 
 
 Virchow's Post-Mortem Examinations. 2d Ed. Cloth, i.oo 
 
 PHYSICAL DIAGNOSIS. 
 
 Bruen's Physical Diagnosis of the Heart and Lungs. By 
 Dr. Edward T. Bruen, Assistant Professor of Clinical Medicine 
 in the University of Pennsylvania. Second Edition, revised. 
 With new Illustrations. a2mo. Cloth, 1.50 
 
 e pages 75 and ib for list of ? Quiz-Compends t 
 
12 STUDENTS' TEXT-BOOKS AND MANUALS. 
 
 PHYSIOLOGY. 
 
 Yeo's Physiology. Third Edition. The most Popular Stu- 
 dents' Book. By Gerald F. Yeo, M.D., F.R.C.S., Professor of 
 Physiology in King's College, London. Small Octavo. 758 
 pages. 321 carefully printed Illustrations. With a Full 
 Glossary and Index. See Page 3. Cloth, 3.00; Leather, 3.50 
 
 Brubaker's Compend of Physiology. Illustrated.- Fourth 
 Edition. Cloth, i.oo; Interleaved for Notes, 1.25 
 
 Stirling. Practical Physiology, including Chemical and Ex- 
 perimental Physiology. 142 Illustrations. Cloth, 2.25 
 
 Kirke's Physiology. New i2th Ed. Thoroughly Revised and 
 Enlarged. 502 Illustrations. Cloth, 4.00; Leather, 5.00 
 
 Landpis' Human Physiology. Including Histology and Micro- 
 scopical Anatomy, and with special reference to Practical Medi- 
 cine. Third Edition. Translated and Edited by Prof. Stirling. 
 692 Illustrations. Cloth, 6.50; Leather, 7.50 
 
 " With this Text-book at his command, no student could fail in 
 
 his examination." Lancet. 
 
 Sanderson's Physiological Laboratory. Being Practical Ex- 
 ercises for the Student. 350 Illustrations. 8vo. Cloth, 5.00 
 
 Tyson's Cell Doctrine. Its History and Present State. Illus- 
 trated. Second Edition. Cloth, 2.00 
 
 PRACTICE. 
 
 Roberts' Practice. New Revised Edition. A Handbook 
 of the Theory and Practice of Medicine. By Frederick T. 
 Roberts, M.D. ; M.R.C.P., Professor of Clinical Medicine and 
 Therapeutics in University College Hospital, London. Seventh 
 Edition. Octavo. Cloth, 5.50 ; Sheep, 6.50 
 
 Hughes. Compend of the Practice of Medicine, sd Ed. 
 
 Two parts, each, Cloth, i.oo; Interleaved for Notes, 1.25 
 
 PART i. Continued, Eruptive and Periodical Fevers, Diseases 
 
 of the Stomach, Intestines, Peritoneum, Biliary Passages, Liver, 
 
 Kidneys, etc., and General Diseases, etc. 
 
 PART n. Diseases of the Respiratory System, Circulatory 
 
 System and Nervous System ; Diseases of the Blood, etc. 
 
 Tanner's Index of Diseases, and Their Treatment. Cloth, 3.00 
 " This work has won for itself a reputation. . . . It is, in 
 
 truth, what its Title indicates." N. Y. Medical Record. 
 
 PRESCRIPTION BOOKS. 
 
 Wythe's Dose and Symptom Book. Containing the Doses 
 and Uses of all the principal Articles of the Materia Medica, etc. 
 Seventeenth Edition. Completely Revised and Rewritten. Just 
 Ready. 321110. Cloth, i.oo; Pocket-book style, 1.25 
 
 Pereira's Physician's Prescription Book. Containing Lists 
 of Terms, Phrases, Contractions and Abbreviations used in 
 Prescriptions, Explanatory Notes, Grammatical Construction of 
 Prescriptions, etc., etc. By Professor Jonathan Pereira, M.D. 
 Sixteenth Edition. 321110. Cloth, i.oo; Pocket-book style, 1.25 
 
 *S~ See pages 2 to 5 for list of New Manuals. 
 
STUDENTS' TEXT-BOOKS AND MANUALS. 13 
 
 PHARMACY. 
 
 Stewart's Compend of Pharmacy. Based upon Remington's 
 Text-Book of Pharmacy. Second Edition, Revised. 
 
 Cloth, i.oo; Interleaved for Notes, 1.25 
 
 SKIN DISEASES. 
 
 Anderson, (McCall) Skin Diseases. A complete Text-Book, 
 
 with Colored Plates and numerous Wood Engravings. 8vo. 
 
 Just Ready. Cloth, 4.50; Leather, 5.50 
 
 " We welcome Dr. Anderson's work not only as a friend, but as 
 
 a benefactor to the profession, because the author has stricken off 
 
 mediaeval shackles of insuperable nomenclature and made crooked 
 
 ways straight in the diagnosis and treatment of this hitherto but 
 
 little understood class of diseases. The chapter on Eczema is 
 
 alone worth the price of the book." Nashville Medical Neius. 
 
 " Worthy its distinguished author in every respect; a work whose 
 practical value commends it not only to the practitioner and stu- 
 dent of medicine, but also to the dermatologist." James Nevens 
 Hyde, M.D., Prof, of Skin and Venereal Diseases, Rush Medical 
 College, Chicago. 
 
 Van Harlingen on Skin Diseases. A Handbook of the Dis- 
 eases of the Skin, their Diagnosis and Treatment (arranged alpha- 
 betically). By Arthur Van Harlingen, M.D., Clinical Lecturer 
 on Dermatology, Jefferson Medical College; Prof, of Diseases of 
 the Skin in the Philadelphia Polyclinic. 2d Edition. Enlarged. 
 With colored and other plates and illustrations. i2mo. Cloth, 2.50 
 Bulkley. The Skin in Health and Disease. By L. Duncan 
 Bulkley, Physician to the N. Y. Hospital. Illus. Cloth, .50 
 
 SURGERY. 
 
 Jacobson. Operations in Surgery. A Systematic Handbook 
 for Physicians, Students and Hospital Surgeons. By W. H. A. 
 Jacobson, B.A., Oxon. F.R.C.S. Eng. ; Ass't Surgeon Guy's Hos- 
 pital ; Surgeon at Royal Hospital for Children and Women, etc. 
 With 199 finely printed illustrations. 1006 pages. 8vo. 
 
 Cloth, $5.00; Leather, $6.00 
 
 Heath's Minor Surgery, and Bandaging. Eighth Edition. 142 
 Illustrations. 60 Formulae and Diet Lists. Cloth, 2.00 
 
 Horwitz's Compend of Surgery, including Minor Surgery, 
 Amputations, Fractures, Dislocations, Surgical Diseases, and the 
 Latest Antiseptic Rules, etc., with Differential Diagnosis and 
 Treatment. By ORVILLE HOKWITZ, B.S., M.D., Demonstrator of 
 Anatomy, Jefferson Medical College ; Chief, Out- Patient Surgi- 
 cal Department, Jefferson Medical College Hospital, sd edition. 
 Very much Enlarged and Rearranged. 91 Illustrations and 
 77 Formulae. i2mo. No. q ? Quiz-Commend ? Series. 
 
 Cloth, i.oo; Interleaved for the addition of Notes, 1.25. 
 
 Pye's Surgical Handicraft. A Manual of Surgical Manipula- 
 tions, Minor Surgery, Bandaging, Dressing, etc., etc. With 
 special chapters on Aural Surgery, Extraction of Teeth, Anaes- 
 thetics, etc. 208 Illustrations. 8vo. Cloth, 5.00 
 
 Swain's Surgical Emergencies. New Edition. Illus. Clo.,i.5o 
 
 *S" See pages 15 and ibfor list of ? Quiz-Compends f 
 
14 STUDENTS' TEXT-BOOKS AND MANUALS. 
 
 Su rge ry ; Con tin ued. 
 
 Walsham. Manual of Practical Surgery. For Students and 
 Physicians. By WM. J. WALSHAM, M.D., F.R c.s., Asst. Surg. 
 to, and Dem. of Practical Surg. in, St. Bartholomew's Hospital, 
 Surgeon to Metropolitan Free Hospital, London. With 236 
 Engravings. See Page 2. Cloth, 3.00; Leather, 3.50 
 
 THROAT. 
 
 Mackenzie. Diseases of the (Esophagus, Nose and Naso- 
 Pharynx. By Sir Morell Mackenzie, M.D., Senior Physician to 
 the Hospital for Diseases of the Chest and Throat ; Lecturer 
 on Diseases of the Throat at the London Hospital, etc., with 
 Formulse and 93 Illustrations. Being Vol. n, complete in itself, 
 of Dr. Mackenzie's text-book on the Throat and Nose. 
 
 Cloth, 3.00; Leather, 4.00 
 
 " It is both practical and learned ; abundantly and well illustrated ; 
 its descriptions of disease are graphic and the diagnosis the best we 
 have anywhere seen." Philadelphia Medical Times. 
 
 Cohen. The Throat and Voice. Illustrated. Cloth, .50 
 
 James. Sore Throat. Its Nature, Varieties and Treatment. 
 
 i2mo. Illustrated. Paper cover, .75; Cloth, 1.25 
 
 URINE, URINARY ORGANS, ETC. 
 
 Acton. The Reproductive Organs. In Childhood, Youth, 
 Adult Life and Old Age. Sixth Edition. Cloth, 2.00 
 
 Beale. Urinary and Renal Diseases and Calculous Disorders. 
 Hints on Diagnosis and Treatment. i2mo. Cloth, 1.75 
 
 Holland. The Urine, and Common Poisons. Chemical and 
 Microscopical, for Laboratory Use. Illustrated, ad Edition. 
 
 Cloth, .75 
 
 Ralfe. Kidney Diseases and Urinary Derangements. 42 Illus- 
 trations. i2mo. 572 pages. Cloth, 2.75 
 
 Legg. On the Urine. A Practical Guide. 6th Ed. Cloth, .75 
 
 Marshall and Smith. On the Urine. The Chemical Analysis of 
 the Urine. By John Marshall, M.D., Chemical Laboratory, Univ. 
 of Penna ; and Prof. E. F. Smith, PH.D. Col. Plates. Cloth, i.oo 
 
 Thompson. Diseases of the Urinary Organs. Eighth 
 London Edition. Illustrated. Cloth, 3.50 
 
 Tyson. On the Urine. A Practical Guide to the Examination 
 of Urine. With Colored Plates and Wood Engravings. 6th Ed. 
 Enlarged. i2mo. Cloth, 1.50 
 
 Bright's Disease and Diabetes. Illus. Cloth, 3.50 
 
 Van Niiys, Urine Analysis. Illus. Cloth, 2.00 
 
 VENEREAL DISEASES. 
 
 Hill and Cooper. Student's Manual of Venereal Diseases, 
 with Formulae. Fourth Edition. i2mo. Cloth, i.oo 
 
 Durkee. On Gonorrhoea and Syphilis. Illus. Cloth, 3.50 
 -93- See pages 15 and ib for list of ? Quiz-Compends * 
 
NEW AND REVISED EDITIONS. 
 
 PQUIZ-COMPENDS? 
 
 The Best Compends for Students' Use 
 in the Quiz Class, and when Pre- 
 paring for Examinations. 
 
 Compiled in accordance with the latest teachings of promi- 
 nent lecturers and the most popular Text-books, 
 
 They form a most complete, practical and exhaustive 
 set of manuals, containing information nowhere else col- 
 lected in such a condensed, practical shape. Thoroughly 
 up to the times in every respect, containing many new 
 prescriptions and formulae, and over two hundred and 
 thirty illustrations, many of which have been drawn and 
 engraved specially for this series. The authors have had 
 large experience as quiz-masters and attaches of colleges, 
 with exceptional opportunities for noting the most recent 
 advances and methods. The arrangement of the subjects, 
 illustrations, types, etc., are all of the most approved 
 form, and the size of the books is such that they may be 
 easily carried in the pocket. They are constantly being 
 revised, so as to include the latest and best teachings, and 
 can be used by students of any college of medicine, den- 
 tistry or pharmacy. 
 
 Cloth, each $1.00. Interleaved for Notes, $1.25. 
 
 No. i. HUMAN ANATOMY, "Based upon Gray." Fourth 
 Edition, including Visceral Anatomy, formerly published 
 separately. Over zoo Illustrations. By SAMUEL O. L. 
 POTTER, M.A., M.D., late A. A. Surgeon U. S. Army. Professor 
 of Practice, Cooper Medical College, San Francisco. 
 Nos.2and3. PRACTICE OF MEDICINE. Third Edition. 
 By DANIEL E. HUGHES, M.D., Demonstrator of Clinical Medi- 
 cine in Jefferson Medical College, Philadelphia. In two parts. 
 PART I. Continued, Eruptive and Periodical Fevers, Diseases 
 of the Stomach, Intestines, Peritoneum, Biliary Passages, Liver, 
 Kidneys, etc. (including Tests for Urine), General Diseases, etc. 
 
 PART II. Diseases of the Respiratory System (including Phy- 
 sical Diagnosis), Circulatory System and Nervous System; Dis- 
 eases of the Blood, etc. 
 
 *** These little books can be regarded as a full set of notes upon 
 the Practice of Medicine, containing the Synonyms, Definitions, 
 Causes, Symptoms, Prognosis, Diagnosis, Treatment, etc., of each 
 disease, and including a number of prescriptions hitherto unpub- 
 lished. 
 
 (OVER.) 
 
BLAKISTON'S ? QUIZ-COMPENDS ? 
 
 Continued. 
 Bound in Cloth, $1.00. Interleaved, for Notes, $1.25 
 
 No. 4. PHYSIOLOGY, including Embryology. Fourth 
 Edition. By ALBERT P. BRUBAKER, M.D., Prof, of Physiology, 
 Penn'a College of Dental Surgery ; Demonstrator of Physiology 
 in Jefferson Medical College, Philadelphia. Revised, Enlarged 
 and Illustrated. 
 
 No. 5. OBSTETRICS. Illustrated. Fourth Edition. By 
 HENRY G. LANDIS, M.D., Prof, of Obstetrics and Diseases of 
 Women, in Starling Medical College, .Columbus, O. Revised 
 Edition. New Illustrations. 
 
 No. 6. MATERIA MEDICA, THERAPEUTICS AND 
 PRESCRIPTION WRITING. Fifth Revised Edition. 
 With especial Reference to the Physiological Action of Drugs, 
 and a complete article on Prescription Writing. Based on the 
 Last Revision of the U. S. Pharmacopoeia, and including many 
 unofficinal remedies. By SAMUEL O. L. POTTER, M.A., M.D., 
 late A. A. Surg. U. S. Army; Prof, of Practice, Cooper Medical 
 College, San Francisco. Improved and Enlarged, with Index. 
 
 No. 7. GYNAECOLOGY. A Compend of Diseases of Women. 
 By HENRY MORRIS, M.D., Demonstrator of Obstetrics, Jefferson 
 Medical College, Philadelphia. In Press. 
 
 No. 8. DISEASES OF THE EYE AND REFRACTION, 
 including Treatment and Surgery. By L. WEBSTER Fox, M.D., 
 Chief Clinical Assistant Ophthalmological Dept., Jefferson Med- 
 ical College, etc., and GEO. M. GOULD, M.D. 71 Illustrations, 39 
 Formulae. Second Enlarged and Improved Edition. Index. 
 
 No. 9. SURGERY. Illustrated. Third Edition. Including 
 Fractures, Wounds, Dislocations, Sprains, Amputations and 
 other operations; Inflammation, Suppuration, Ulcers, Syphilis, 
 Tumors, Shock, etc. Diseases of the Spine, Ear, Bladder, Tes- 
 ticles, Anus, and other Surgical Diseases. By ORVILLE HORWITZ, 
 A.M., M.D., Demonstrator of Anatomy, Jefferson Medical Col- 
 lege. Revised and Enlarged. 77 Formulae and 91 Illustrations. 
 
 No. 10. CHEMISTRY. Inorganic and Organic. For Medical 
 and Dental Students. Including Urinary Analysis and Medical 
 Chemistry. By HENRY LEFFMANN, M.D., Prof, of Chemistry in 
 Penn'a College of Dental Surgery, Phila. A new Edition, Revised 
 and Rewritten, with Index. 
 
 No. ii. PHARMACY. Based upon " Remington's Text-book 
 of Pharmacy." By F. E. STEWART, M.D., PH. G., Quiz-Master 
 at Philadelphia College of Pharmacy. Second Edition, Revised. 
 
 Bound in Cloth, $1. Interleaved, for the Addition of Notes, $1.25. 
 
 These books are constantly revised to keep tip with 
 the latest teachings and discoveries, so that they contain 
 all the new methods and principles. No series of books 
 are so complete in detail, concise in language, or so well 
 printed and bound. Each one forms a complete set of 
 notes upon the subject under consideration. 
 
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