LIBRARY t OF THE UNIVERSITY OF CALIFORNIA. Oats I m Works of ALFRED I. COHN, Ph.G., PUBLISHED BY JOHN WILEY & SONS. Indicators and Test-papers. Their Source, Preparation, Application, and Tests for Sensitiveness. With Tabular Summary of the Applica- tion of Indicators. Second Edition, Revised and "En- larged. i2mo, ix -f- 267 pages. Cloth, $2.00. Tests and Reagents, Chemical and Microscopical, known by their Authors' Names; together with an Index of Subjects. 8vo, iii+sSs pages. Cloth, $3.00. Fresenius' Quantitative Chemical Analysis. New Authorized Translation of the latest German Edition. In two volumes. By Alfred I. Cohn, Ph.G. Recalculated on the basis of the latest atomic weights, and also greatly amplified by the translator. (In press.) TESTS AND REAGENTS CHEMICAL AND MICROSCOPICAL KNOWN BY THEIR AUTHORS' NAMES, TOGETHER WITH AN INDEX OF SUBJECTS. COMPILED FOR THE USE OF CHEMISTS, MICROSCOPISTS, PHARMACISTS, STUDENTS, ETC. BY ALFRED I. COHN, Pn.G. AUTHOR OF " INDICATORS AND TEST-PAPERS ". MEMBER OF THE AMERICAN CHEMICAL SOCIETY ; SOCIETY OF CHEMICAL INDUSTRY ; VEREIN DEUTSCHER CHEMIKER ; ETC. FIRST EDITION NEW YORK JOHN WILEY & SONS LONDON: CHAPMAN & HALL, LIMITED 1903 GENERAL Copyright, 1903, BY ALFRED I. COHN. Entered at Stationers' Hall. ROBERT DRUMMOND, PRINTER, NEW YORK. PREFACE. THE matter here presented was compiled from a great num- ber of sources (the small brochures of Altschul, Schneider, and Wilder having served as a nucleus), and with very numerous additions was published in a series of monthly installments in MERCK'S REPORT, from March 1900 to September 1902 ; it is here republished by the kind permission of Messrs. Merck & Co. Since its first appearance in serial form, however, the matter has been further greatly amplified. The compilation has been made with a view to supplying the busy chemist, microscopist, and pharmacist with data which are frequently desired, but which are often either not at hand, or inaccessible. While the nature of the subject precludes any claim being made as to completeness, it is believed, neverthe- less, that the contents of the volume will be sufficiently exten- sive to be of practical utility. ALFRED I. COHN. NEW YORK, January, 1903. 8093 TESTS AND REAGENTS. Abram (LEAD IN URINE). Add ammonium oxalate to urine (1:150 and introduce metallic magnesium (wire or rod). Lead is precipitated on the magnesium, and can be identified by warming with fragment of iodine yellow lead iodide; or dissolving in nitric acid and applying other reagents. Sensi- tive to i : 50,000. Adamkiewicz (ALBUMIN). Acetic-acid solutions of albuminous substances are colored violet by cone, sulphuric acid, and show greenish fluorescence. A similar reaction results if albu- min is treated with a mixture of i vol. cone, sulphuric acid and 2 vol. glacial acetic acid. Heating hastens reaction, and, according to Wurster, so does addition of a few grains sodium chloride. Gelatin gives no reaction. Adamkiewicz (NERVE-CENTER STAIN). Harden sections in Muller's solution for i to 3 months, wash with water, then with water acidulated with nitric acid, then stain with cone, solu- tion safranine. Remove superfluous color, clear with alcohol and clove oil, pass into water again, wash in water acidulated with acetic acid, stain with methylene blue, and clear as before. Myelin is stained red; nuclei violet. Adams (FAT IN MILK ANALYSIS). Diy a known quantity of milk on a fat-free paper coil, then extract latter with ether in a Soxhlet apparatus. Adrian (DIFFERENTIATING NATURAL AND ARTIFICIAL METHYL SALICYLATES). Carefully overlay 5 Cc. methyl salicylate on 5 Cc. cone, sulphuric acid. A synthetic product affords a slight development of heat and a faint pink color. Natural oil de- velops decided heat, and liquid becomes pink, changing to a wine-red and finally reddish-brown. 2 TESTS AND REAGENTS. Adrian (ESTIMATING GUAIACOL). i. Heat 100 Gm. with 10 Cc. water for i hour in a current of HBr gas, take up residue (containing pyrocatechol and homopyrocatechol) with ether, evaporate solvent, and treat residue with benzene. From weight of pyrocatechol so obtained and after recrystallizing, calculate percentage of guaiacol. 2. Dissolve 5 Gm. guaiacol in a little water and 10 Cc. alcohol, and make up solut. to i ,000 Cc. Mix 20 Cc. solut. in a test tube with i Cc. i : 100 NaNO 2 solut. and i Cc. dil. (1:200) HNO 3 characteristic reddish- brown color develops, and is compared within 10 minutes with that of a standard solut. Agostini (GLUCOSE). Mix 5 drops urine, 5 drops 0.5-% gold- chloride solution, and 3 drops 20-% potassa solution and warm gently ; sugar will give a red color. Alferow (SILVER STAIN). Acid solution of silver picrate (or lactate, acetate, or citrate), prepared by adding 10 to 15 drops cone, solution of acid of the salt taken to 800 Cc. solution of salt. Alf raise (IODINE). Add i drop hydrochloric acid to 10 Cc. water containing i% each of starch and potassium nitrate, and boil, i drop of this reagent gives blue color if iodine present in sus- pected liquid. Alleger (GELATIN MOUNTING PROCESS). Add few drops for- maldehyde to each gramme 0.5- to i-% gelatin solution. Mount section in this, heat slide till paraffin is softened, and let gelatin excess drain from edge of slide. Allen (EMBRYO STAIN). Dissolve i part methylene blue and 7^ parts sodium chloride in 1,000 parts water, and dilute with 15 to 20 volumes sea- water. Allen (FATS, VEGETABLE). Shake together equal volumes fat and nitric acid (sp. gr. 1.4) for | minute, then set aside for 15 minutes. Vegetable fats (cottonseed oil) afford coffee-brown color. Allen (FEHLING'S TEST, MODIFIED). Boil 7 to 8 Cc. urine, add 5 Cc. Fehling's cupric-sulphate solution, cool, and add i to 2 Cc. faintly acid saturated solution sodium acetate. Filter, add 5 Cc. Fehling's alkaline tartrate solution, and boil. Allen (NITROGEN IN URINE). Modification of Knopp's method. Boil 25 Cc. urine with 10 Cc. strong sulphuric acid in porcelain TESTS AND REAGENTS. 3 dish till volume reduced to 10 Cc. and sulphuric acid vapors evolved. Transfer liquid to Kjeldahl flask, add 5 Gm. potas- sium sulphate, and heat till liquid pale-yellow. Cool, neu- tralize with cone, caustic soda, and add water to 100 Cc. Treat 10 Cc. of neutral solution with alkaline hypobromite as in urea estimation. Each Cc. nitrogen = 0.00 12 Gm. urea (approx.). Allen (PHENOL), i or 2 drops suspected liquid, few drops of hydrochloric acid, and i drop nitric acid, give purple-crimson if phenol present. Allen (SPIRIT NITROUS ETHER). Fill an Allen nitrometer with strong brine and introduce 5 Cc. spirit to be tested. Then add 5 Cc. strong solution potassium iodide, then 5 Cc. dil. sulphuric acid. Shake. When action ceases, adjust surfaces of liquid in both limbs to same level; read off volume of nitric oxide, and add 1.5 Cc. as correction for solubility of gas in solution. Multiply volume by 0.0638; result = parts ethyl nitrite in 100 by weight of spirit. Allen (STRYCHNINE). Extract with ether, concentrate by let- ting fall by drops into warmed porcelain capsule, cool resi- due, and treat with sulphuric acid and manganese dioxide. Strychnine gives violet color. Allen (ZINC IN SOLUTION). Few drops of potassium-ferrocy- anide solut. causes white precipitate in slightly alkaline, boiling solution containing zinc. Allesandri-Guaceni (NITRIC ACID; NITRATES). Dissolve a few Gm. phenol in hydrochloric acid by heating 12 hours on water-bath. Heat 10 drops of reagent with dry residue of suspected liquid on water-bath. Nitric acid or nitrates give intense violet color, changed by ammonia to green. Alme"n (ALBUMIN), i. 4 Gm. tannin, 8 Cc. 25-% acetic acid, and 190 Cc. 40- to 50-% alcohol. Also precipitates nucleoalbu- min. 2. Mix i part 2-% tannin solution in dilute alcohol with 6 parts urine. Albumin causes turbidity. Alme"n (BLOOD). Shake liquid containing blood, with mixture of equal parts guaiac tincture and turpentine oil; becomes blue owing to oxidation of guaiac resin. Color is permanent on heating. See also Weber and Schoenbein. Almen (CARBOLIC OR SALICYLIC ACID). Dissolve mercury in 4 TESTS AND REAGENTS. fuming nitric acid and dilute solut., with double its vol. of water. Add 5 to 10 drops of reagent to 20 Cc. of liquid and boil carbolic or salicylic acid affords a yellow ppt. ; on add- ing nitric acid until ppt. is dissolved liquid acquires a red color. Sensitiveness, i : 400,000. Alme'n (GLUCOSE). Digest 2 Gm. basic bismuth carbonate with 100 Cc. potassa solution, sp. gr. 1.33, and 4 Gm. Rochelle salt, cool clear solution and decant from precipitate. Boil i Cc. of reagent for several minutes with 10 Cc. of urine. Glucose produces yellowish-brown precipitate, which becomes darker, and finally black. Also known as Boettger-Almen reagent. Compare with Nylander's solution. Alme'n (HYDROCYANIC ACID). Make solut. alkaline with soda lye, add yellow ammonium sulphide, evaporates to dryness, exhaust residue with water, then add hydrochloric acid and ferric chloride. In concentrated solutions a blood-red color develops in very dilute an orange-red. Sensitiveness, 1:4,000,000. Alm6n (PHENOL), i. Dissolve i part mercury in i part nitric acid sp. gr. 1.4, and dilute with 2 volumes water. On heating to boiling 5 to 10 drops of this with 20 Cc. solut. containing phenol yellow precipitate forms, soluble in nitric acid with red color. 2. Blue color forms on adding ammonia and chlorin- ated-soda solution to phenol solution. Alm&i-Nylander (GLUCOSE). See Almen's glucose test. Alpers (ALBUMIN IN URINE). Acidulate urine with hydro- chloric acid, and add equal vol. of i-per cent, mercury-suc- cinimide solution a white cloudiness forms. Sensitiveness, i : 150,000. Alt (NERVE STAIN). Solution of Congo red in absolute alcohol. Squire recommends a 2-% aqueous solution. Altmann (AMMONIUM MOLYBDATE). 2.5-% ammonium-molyb- date solution containing about 0.25-% chromic acid. Altmann (CORROSION METHOD). Inject tissue with olive oil, then immerse thin slices for 24 hours in i-% osmic-acid solu- tion, then treat with Javelle water for several hours till cor- rosion completed, finally dry with blotting-paper, and mount in glycerin. TESTS AND REAGENTS. 5 Altmann (FIXING SOLUTION). Mixture of equal parts of 5-% potassium-bichromate solution and 2-% osmic-acid solu- tion. Altmann (IMPREGNATION METHODS), i. Immerse small por- tions fresh tissue for 5 to 8 days in mixture of 2 vol. olive oil and i vol. each of ether and absolute alcohol, then throw into water to precipitate oil in the tissue, next harden with osmic acid, corrode with Javelle water, and mount in glycerin. 2. Impregnate with mixture of 2 vol. castor oil and i vol. alcohol, then proceed as in i . Altmann (NITRIC ACID). A 3- to 3.5-% aqueous solution used as a fixing agent. Sp. gr. about i .02. Alvarez-Jean- (SULPHIDES, HYPOSULPHITES AND SULPHITES OF ALKALI METALS). Sulphides give a violet color with sodium nitroprussiate. Hyposulphites in dilute solution give a yel- lowish-brown precipitate with a cone, solut. of bismuth sub- nitrate and potassium nitrate in water with smallest possible quantity of nitric acid to effect solution. An excess of this reagent gives a precipitate also with sulphites. Anderson (DISTINGUISHING BETWEEN QUINOLINE AND PYRI- DINE SALTS). Chloroplatinates of the latter, boiled with water, are converted into insoluble double salts with lib- eration of hydrochloric acid; those of former remain in solu- tion. Anderson (PAPAVERINE). Dark- red color appears on adding concentrated nitric acid to solution of papaverine in dilute nitric acid, and yellow crystals separate. Andr6 (QUININE). Chlorine and ammonia produce green color changing to blue on saturation with acid. Excess of acid changes color to violet or bright red, but ammonia again turns it green. Andreasch (CYSTEIN). On adding few drops of dilute ferric- chloride solution, followed by ammonia, to solution of cystein acidulated with hydrochloric acid, a beautiful red color forms and darkens on shaking, after exposure to air. Andreasch (!RON). Dark purplish-red color forms on adding little ammonia and sulphoglycolic acid to solution containing iron; the color soon fades, but reappears on shaking after exposure to air. 6 TESTS AND REAGENTS. Anstie (ALCOHOL IN URINE). Solut. of potass, bichromate i, in cone, sulphuric acid 300. Add reagent by drops. Em- erald-green color signifies presence of alcohol in toxic quantity. Apathy (HEMATOXYLIN STAIN). Stain in i-% solution hema- toxylin in 70- or 80- % alcohol, and wash out in i-% potas- sium-bichromate solution in alcohol of the same strength. Bichromate solution should be freshly made by mixing one part of 5-% aqueous solution with about 4 parts of 80- to 90-% alcohol. Apathy (METHYLENE-BLUE PROCESS). Wash -preparations stained with strong methylene-blue solution in salt solution (0.75-%), then place for an hour or more in freshly-prepared i- to 2-% solution neutral ammonium carbonate saturated with picrate. If methylene-blue solution is very dilute omit treat- ment with salt solution. Afterwards immerse preparation in saturated solution of ammonium picrate in 50-% glycerin,, then transfer to saturated solution of the picrate in mixture of 2 parts glycerin (50-%), i part of cold saturated sugar solution, and i part of cold saturated gum-arabic solution. When thoroughly penetrated, mount in Apathy's mounting- medium. Apathy (MOUNTING MEDIUM). Picked acacia 50 Gm.; cane sugar, 50 Gm.; distilled water, 50 Gm. Dissolve on water- bath and add 0.05 Gm. thymol. This medium sets very hard and, combined with a paper cell, may be used for ringing gly- cerin mounts. Arata (ARTIFICIAL DYES IN WINE). Wool immersed in wine containing artificial dyes abstracts these from the wine. The fiber may be afterwards subjected to special reactions. Archetti (CAFFEINE; URIC ACID). Heat a solution of potassio- ferric cyanide with half its vol. of nitric acid to boiling, then dilute with water. Reagent gives a precipitate of Prussian blue with caffeine (uric acid does also). Arndt. Determination of sugar by means of the ferment sac- charometer. See Einhorn. Arnold (ACETO-ACETIC ACID IN URINE), a. Dissolve i Gm. para-amido-acetophenone in 80 to 100 Cc. water by shaking and adding hydrochloric acid by drops, then add more cone, acid till solution is colorless, b. Dissolve T Gm. sodium ni- TESTS AND REAGENTS. 7 trite in 100 Cc. dist. water. Just before using mix 2 parts a with i part 6, add an equal vol. urine, and 2 or 3 drops cone, ammonia water an intense brownish-red de- velops with every urine. Now add i vol. of this colored urine to 10 to 12 vols. cone, hydrochloric acid a beauti- ful purplish- violet develops if aceto-acetic acid present. Strongly colored urine should first be decolorized with ani- mal charcoal. Arnold (ALKALOIDAL TESTS), i. Some alkaloids, heated on water-bath with syrupy phosphoric acid obtained by dissolv- ing metaphosphoric acid or phosphoric acid anhydride in 2 5~% phosphoric acid yield characteristic color reactions: Aconitine violet; nicotine yellow; coniine green. 2. Triturated with concentrated sulphuric acid, many alkaloids yield characteristic color reactions upon adding 30- to 40-% alcoholic (in some instances aqueous) potassa solu- tion. Arnold (CODEINE). Heat fragment with a few drops cone, sul- phuric acid and add by drops an excess of a 30- to 40-% alcoholic or aqueous solut. potassa mixture should remain colorless but a dirty-yellow develops, changing to lemon- yellow, if colchicine present. Arnold (NARCEINE). On warming substance containing nar- ceine with cone, sulphuric acid and trace of phenol, a reddish color forms. Arnold- Vital! (ALKALOIDAL TESTS). Particle of alkaloid trit- urated with concentrated sulphuric acid, and a grain of so- dium nitrate is added; then, strong alcoholic (40-%) potassa solution. Number of alkaloids give characteristic color reactions. Atropine and homatropine give orange color, which, on addition of potassa, becomes reddish- violet and fades to rose-red. Arzberger (OiL PEPPERMINT). Warm i drop of oil with 5 Cc. formaldehyde rose-red color develops (not given by menthol or menthenes). Add cone, acetic acid a handsome red color forms, changing rapidly to violet-red and finally dirty-brown. Japanese oil does not give this reaction, and various pepper- mint oils give different colors. Spearmint, melissa, bay, lav- ender, and pinus oils do not give the reaction. 8 TESTS AND REAGENTS. Ashby (MINERAL ACIDS IN VINEGAR). Logwood infusion (i : 50) in boiling water. After standing few hours place few drops on porcelain, add drop of the suspected sample and evaporate to dryness on water-bath. If mineral acids present residue has red color. Pure vinegar leaves bright-yellow stain. Astolfi (SANTONICA). Powder i Gm. of the substance and shake with 10 Cc. absolute alcohol for some time, then boil and filter. Now add a small piece caustic potassa and heat again if article is good, distinct red develops; if much adulterated, color will be yellowish-red; if no genuine santonica present, sample will not color at all. Austen-Chamberlain (NITRIC ACID). A rose-red color is pro- duced with solution of 20 Gm. iron and ammonium sulphate, 2 Gm. sulphuric acid, and 100 Cc. of water. Autenrieth (INDICATOR). Luteol (oxychlordiphenylquinoxa- line). Gives with alkalies a yellow color, rendered colorless by acids. Autenrieth- Hinsberg (PHENACETIN). Add 10- to 12-% nitric acid to powdered substance and heat to boiling yellow crys- talline needles deposit. Antipyrine and acetanilid do not re- spond. Axenfeld (ALBUMIN). o.i-% solution gold chloride. Acidulate solution to be tested with formic acid and heat with drop of reagent. If albumin present, solution becomes purplish-red; on addition of more gold chloride, blue. Latter color reaction also produced by glucose, starch, tyrosine, leucine, etc., but purplish color is characteristic of albumin. Aymonier (ALPHA-NAPHTOL). 15-% alcoholic solution alpha- naphtol colored violet on adding cane sugar, and admixture of 2 vol. sulphuric acid. On addition of one drop of mixture of i part potassium bichromate, 10 parts water and i part con- centrated nitric acid, the alpha-naphtol solution yields black precipitate. Beta-naphtol gives neither of these reactions. Azoulay (OsMic-AciD METHOD). Harden thin sections of material in Mtiller's solution, place for 5 to 15 minutes in osmic-acid solution (i : 500 or i : 1,000), then rinse with water and leave for 2 to 5 minutes in a 5- or io-% tannin solution, the latter being warmed meanwhile until vapor given off. After TESTS AND REAGENTS. 9 washing in water, double-stain sections with carmine or eosine, and mount in balsam. Babes (ACTINOMYCOSIS). Stain sections in Babes' safranine solution No. 3 for 2 minutes, rinse in alcohol, and decolorize in Gram's solution. Babes (SAFRANINE STAINS), i. Mixture of equal parts con- centrated alcoholic and aqueous solutions of safranine. 2. Cone, or supersaturated solution made with the aid of heat. 3. Mix 100 parts water, 2 parts aniline, and an excess of safranine. Warm mixture to 60 to 80 C. and filter through wet filter. Babo (URic ACID). Boil dilute Fehling's solut. with a urate of an alkali cuprous oxide is precipitated. If uric acid present in excess, a white precipitate of cuprous urate also deposits, decomposed on boiling with caustic alkali into a urate and cuprous oxide. Bach (BUTTER). Butter is soluble in 20 parts of a mixture of 3 vol. ether and i vol. 95-% alcohol at 19 to 21 C. Foreign fats, lard, tallow, etc., are insoluble or but slightly so, even on warming some degrees above 20 C. Bach (COPPER). Mix equal molecular weights of formaldehyde in 2o-per cent solution with hydroxylamine hydrochlorate (formaldoxim results). Add to 15 Cc. of solut. to be tested 0.5 Cc. of formaldoxim solution and 0.5 Cc. potassa lye an intense violet develops in even very dilute copper solu- tions. Bach (HYDROGEN DIOXIDE), a. 0.03 Gm. potassium bichro- mate and 5 drops aniline in i liter of water; b. 5-% oxalic- acid solution. Shake 5 Cc. of solution to be tested, with 5 Cc. solution a and i drop solution b; violet-red color forms if hydrogen dioxide present. Bach (SOLANINE). Treatment with equal volumes sulphuric acid and alcohol develops a red color. Bachmeier (ALKALIES). Tannin solution produces a red to reddish-brown color, changing to dirty green. Bachmeier (ORGANIC ACIDS IN PHENOL). Aqueous Brazil- wood decoction is permanently discolored by organic acids, but not by phenol. Baemes (TANNIN). Solution of i Gm. sodium tungstate and 2 io TESTS AND REAGENTS Gm. sodium acetate in each io Cc. precipitates from acid or alkaline tannin solutions, straw-yellow precipitate insoluble in water. Baeyer (EosiNE). Shake with water and sodium amalgam, heat gently, then dilute with water, and add drop of potassium permanganate solution opaque green color appears in re- flected light. Baeyer (GLUCOSE). Heat solution with excess of nitrophenyl- propiolic acid and soda blue color appears if glucose present, owing to formation of indigo. Bailey (NITRIC ACID). Crystals of the double compound of mercuric cyanide and potassium iodide turn black when intro- duced into nitric acid, but red in other acids. Bailey (SULPHUR). A blood-red color forms on heating with sodium carbonate, dissolving in water and adding sodium nitro-prusside solution. Balmer-Fraentzel (TUBERCLE BACILLI STAIN). Immerse sec- tions for 24 hours in solution of 2 Gm. freshly powdered gentian violet in 100 Gm. aniline water. Subsequently treat as in Ehrlich's method. Bar bier (ALCOHOL IN ESSENTIAL OILS). A viscid solution is formed on distilling off about one-tenth and adding to distil- late excess of dry potassium acetate. Compare Bernouilly's test. Barbot (FATTY OILS). Fuming nitric acid with different oils behaves differently with regard to coloration and solidifica- tion e. g. : Olive oil yields a white (not red or brown) mixture, which solidifies in i to 2 hours. Barbsche (GLYCERIN). No blue color should be produced on adding one drop ferric- chloride solution to glycerin diluted with 20 volumes water containing one drop carbolic acid. Barff (PRESERVATIVE MEDIUM). Saturated solution boric acid in glycerin (boroglyceride) is prepared by application of mod- erate heat for 4 or 5 hours. When required for use i part of solid product is dissolved in 40 parts by weight of water Barfoed (GLUCOSE). Solution of 14 Gm. crystallized ' copper acetate in 200 Cc. water, and. 5 Cc. acetic acid; or, according to a more recent formula, 0.5 Gm. copper acetate, 100 Cc water, and i Cc. acetic acid. Glucose reduces solution in the TESTS AND REAGENTS. n cold, and more rapidly on heating. Dextrin, cane sugar, and milk sugar do not reduce solution. Used also for distinguish- ing between glucose and lactose in urine. Barfoed (HYDROCYANIC ACID). Acidify solution with sulphuric or tartaric acid and shake with ether; the latter takes up hydrocyanic acid, but not hydro-ferrocyanic acid. Barfoed (SILICIC ACID). Cautiously heat mixture of i part of suspected substance, and 2 parts cryolith with 4 to 6 parts of sulphuric acid, and hold near surface of mass a thin platinum wire loop containing a drop of water; white pellicle of silicic hydrate will form on the water. Barral (ALBUMIN, AND BILIARY PIGMENTS). Overlay urine with a 20-% solut. sozolic acid a white ring develops at con- tact point if albumin present ; a green ring if biliary pigments. Barralet (HYDROGEN DIOXIDE). The pale-blue freshly pre- cipitated ferrous ferrocyanide obtained by adding solut. po- tassium ferrocyanide to a solut. of a ferrous salt is immediately changed into Prussian blue by hydrogen dioxide even in very dilute solution of H 2 O 2 . Barreswil (CHROMIC ACID). Blue color appears on adding few drops of chromic-acid solution and a little ether to a very dilute, acidified hydrogen-dioxide solution. Barreswil (GLUCOSE). Reduction takes place on boiling a liquid containing glucose with the following solution: 60 Gm. potassium hydroxide; 40 Gm. potassium tartrate, and 200 Cc. water; then dissolve 65 Gm. copper sulphate in 560 Cc. water and add the first solution. Bartley (BILIARY PIGMENTS). On adding HC1 and Fe 2 Cl e to a liquid (e. g. urine) containing bile, an intense green color develops. Barry (HYDROCYANIC ACID). Acidify liquid slightly, if neces- sary, with acetic acid, then put 2 or 3 drops in a watch-glass. Cover with another watch-glass containing 2 or 3 drops i-% silver-nitrate solution; latter becomes cloudy if hydrocyanic acid present. Basham (BILIARY PIGMENTS). Shake liquid with chloroform, decant, evaporate chloroform, and add a drop nitric acid to residue. Play of colors, finally ending in ruby-red, ensues. Reaction very delicate. '12 TESTS AND REAGENTS. Basoletto (SESAME OIL). Mixture of equal volumes sesame oil and 2-% solution cane sugar in hydrochloric acid, sp. gr. 1.124, is colored red in the cold, but more rapidly on heating. With glucose and lactose, color is produced only when mixture is boiled with the hydrochloric acid and allowed to become perfectly cold. Compare Baudouin's test. Bastelaer (PHOSPHORUS IN TISSUES AND EJECTA). Dissolve out phosphorus with ether by repeated shaking, evaporate, add water at end of evaporation, warm to 50 or 60 C., shake with cone, ammonia, then wash with dil. sulphuric acid, and then with water. Residue = phosphorus, recognizable by its properties. Bastion (GOLD STAIN). Solution of gold chloride (1:2,000), acidulated with hydrochloric acid (i drop to 75 Cc.). Bates (EXAMINING BACTERIAL CULTURES). Remove a little of growth by means of sterilized platinum hook or small loop , and spread on a cover- glass in as thin a film as possible. When almost dry allow one or two drops of weak aqueous methyl- violet solution to fall on film from pipette. Carefully turn cover-glass over on to a slide after a minute, then gradually remove excess of stain by gentle pressure with strip of filter paper. Bates (SAFRANINE SOLUTION). Saturated solution in aniline 3 Cc. and distilled water 90 Cc., prepared at 60 C. and after- wards filtered. Bates (STAINING KOCH COMMA BACILLI). Leave sections for 24 hours in aqueous solution fuchsine, then wash in distilled water faintly acidulated with acetic acid, or in sublimate solu- tion (1:1000). Afterwards, pass rapidly through alcohol and clove oil, dry with filter paper, and preserve in balsam. Bates (STAINING LEPROSY BACILLI). Stain with solution of rosaniline hydrochlorate in aniline water, decolorize in 33-% hydrochloric acid, and after-stain with methylene blue. Bauer (SOLANINE). Add a few drops of a solution of telluric acid in diluted sulphuric acid to the alkaloidal solut. in a watch-glass and warm slightly on water-bath a raspberry- fed color develops and persists 2 or 3 hours. Reaction very delicate. Atropine, morphine, quinine, etc., do not give the reaction. TESTS AND REAGENTS. 13- Baudouin (SESAME OIL), o.i Gm. sugar dissolved in 10 Cc, hydrochloric acid sp. gr. 1.18. One volume of solution is. shaken with 2 volumes of oil to be tested. If sesame oil pres-. ent, the oil on separation is cherry-red. Lewin carries out reaction as follows: Cover 0.5 Gm. pow-. dered sugar with 2 Cc. of oil in test-tube, and then pour i Cc.. hydrochloric acid, sp.gr. 1.18, carefully down side of the tube. If sesame oil present, a rose-red zone appears within i to 5 minutes. According to Millian, Baudouin's test is more delicate when carried out with well dried, free, fatty acids from oil to be- tested. Villavecchia and Fabris replace sugar and hydrochloric- acid by furfurol. Compare also Carlinjanti, and Gassend. Baumann (POLYATOMIC ALCOHOLS, CARBOHYDRATES, AND DIA- MINES). Benzoyl chloride added to solution of alcohol or amine in aqueous soda-solution, produces insoluble benzoyl esters. Test can be used for detection of glycerin, carbohy- drates and various bacterial products in urine. Baumann- Goldman (CYSTINE). Benzoyl chloride, dissolved in aqueous sodium-hydroxide solution, throws down a precipitate, of benzoyl-cystine. Baumann- Preusse (HYDROQUINONE). Heat substance rapidly in open test-tube violet fumes evolved, condensing as an. indigo-blue sublimate if hydroquinone is present. Baumgarten (BLEU DE LYON STAIN). Place sections of ma-, terial previously stained with borax-carmine for 12 hours in 0.2-% solution bleu de Lyon in absolute alcohol, and wash out for 6 hours before mounting in balsam. Baumgarten (FUCHSINE AND METHYLENE-BLUE STAIN). Place- sections of material hardened in chromic-acid solution for 24 hours in watch-glassful water containing 8 to 10 drops cone, alcoholic solut. fuchsine. Rinse with alcohol, stain for 4 or 5 minutes in cone, aqueous solution methylene blue, wash out with alcohol for 5 to 10 minutes and clear with clove-oil.. Nuclei are stained red, and tissues blue. Baumgarten (LEPRA-BACILLUS STAIN). Stain 6 to 7 min. in cold dil. alcoholic solut. fuchsine, and decolorize for 15 seconds, in acidulated alcohol (iHNO 3 and 10 alcohol); rinse in water, 14 TESTS AND REAGENTS. and double-stain in aq. solut. methylene blue. Lepra bacilli stain red on blue ground; tubercle bacilli do not stain in this space of time. Baumgarten (TUBERCLE BACILLI EXAMINATION). Immerse cover-glass preparations in watch-glass of distilled water con- taining i to 2 drops 33-% potassa solution, then press down on slides and examine unstained. If putrefactive bacteria present, stain with aqueous fuchsine or gentian violet to dis- tinguish from tubercle bacilli which remain colorless. Baumgarten (TUBERCLE BACILLI, NEW METHOD FOR). Stain sections in watch-glassful water containing 4 to 5 drops cone, alcoholic methyl- violet solut. Wash in water, immerse for 5 minutes in semi-saturated potassium-carbonate solut. if necessary, and decolorize in absolute alcohol for 5 to 10 min- utes. Pass through clove-oil, mount in equal parts Canada balsam (free from chloroform) and clove oil, place sections in alcohol for 5 minutes, then in cone, solut. of Bismarck brown in i-% acetic acid. Bayer (ACETONE IN URINE). Mix urine (or distillate) with equal vol. of solut. of nitrobenzaldehyde in water, then add soda or potassa to alkalinity indigo blue formed. Sensitive to 1:2500. Also known as Drewsen's, or Penzoldt's, indigo test. Bayer (!NDOL). Indol solution yields red color or precipitate on addition of dilute nitric acid and dilute potassium-nitrite solution. Bayerl (DECALCIFYING FLUID). Equal parts 3-% chromic-acid solut. and i-% hydrochloric acid. Bayrac (URIC ACID IN URINE). Evaporate 50 Cc. urine to dryness on water-bath, treat residue with hydrochloric acid (1:5), wash residue with alcohol, dissolve in 20 drops sodium- hydroxide solution heated to 90 or 100 C. on water-bath, and decompose with sodium hypobromite in apparatus for determining urea. Each i Cc. nitrogen at ordinary tem- perature equals 0.00357 Gm. uric acid. Beale (AMMONIA CARMINE), i. Carmine, 15 grn.; strong solu- tion ammonia, 30 min.; glycerin, 2 fl. oz.; alcohol, 6 fl. dr. This fluid was specially designed for purpose of staining by means of injection. 2. Carmine, 10 grn.; strong solution TESTS AND REAGENTS. 15 ammonia, 30 min.; distilled water, 2 fl. oz.; alcohol, 4 fl. dr.; glycerin, 2 fl. oz. Dissolve carmine in ammonia with heat, boil for few seconds, and cool. Then evaporate excess of ammonia, add other ingredients, and filter. If any carmine deposits on keeping, add one or two drops ammonia to redis- solve. Beale (CARMINE GLYCERIN MASS). Dissolve 5 grains carmine with 5 drops ammonia in little water, and add to 4 fl. dr. glycerin. Then add gradually, with agitation, 4 fl. dr. gly- cerin, containing 8 to 10 drops acetic or hydrochloric acid. If necessary add more acid to insure decided acidity. Finally add glycerin 4 fl. dr., alcohol 2 fl. dr., and water 6 fl. dr. Beale (CEMENT). Thick solution of shellac in alcohol. Addi- tion of 20 drops castor oil to each fl. oz. has been recom- mended. .Beale (CREOSOTE MOUNTING MIXTURE). Dissolve n Gm. creosote in 180 Gm. methyl alcohol, add sufficient chalk to make thick paste, then add 1920 Gm. water gradually, con- stantly stirring, then a few fragments camphor. After stand- ing several weeks, filter. Beale (DIGESTION FLUID). Dissolve dried mucus from the stomach glands of pig (or, prepared pepsin) in water or gly- cerin, and keep tissues in solution for some hours at 37 C. Beale (GLYCERIN JELLY). Soak gelatin or isinglass for 2 or 3 hours in cold water, then remove and melt. Cool, but while still fluid, add a little white of egg, shake well, and heat to boiling-point. Filter through fine flannel to remove coagu- lated albumin, and to clear solution add equal bulk of glycerin. Beale (PRUSSIAN- BLUE GLYCERIN MASS). a. Potassium ferrocyanide 12 grains; glycerin, 4 fl. dr.; water, 4 fl. dr. b, Tinct. ferric chloride, i fl. dr.; glycerin, 4 fl. dr.; water, 4 fl. dr. Add b to a very gradually, shaking well after each addition. Then add alcohol, i fl. oz., and water, 3 fl. oz., shaking mixture constantly. Preserve injected specimens in acidulated glycerin. Beale (PRUSSIAN-BLUE GLYCERIN MASS, ACID), a. Potas- sium ferrocyanide, 3 grains; glycerin, i fl. oz. b. Tinct. ferric chloride, 10 drops; glycerin, i fl. oz. Add b to a by 1 6 TESTS AND REAGENTS. drops, then add water, i fl. oz. and strong hydrochloric acid, 3 drops. If desired, add also 2 fl. dr. alcohol. Bechamps (NITROBENZENE). Essential oil almonds adulterated with nitrobenzene yields blue color on distilling with ferric acetate, and adding chlorinated lime to distillate. Bechi (COTTONSEED OIL). Warmed with an alcoholic ethereal silver-nitrate solution, cottonseed oil (or colza oil if present) yields reddish-brown color; olive oil and other oils remain uncolored. The Swiss Society for Analytical Chemists in 1895 suggested the following reagent: Dissolve i Gm. silver nitrate in 5 Cc. water, 200 Cc. alcohol, 20 Cc. ether, and add i Cc. nitric acid, sp. gr. 1.4. To test for cottonseed oil, mix 10 Cc. of fat and 3 Cc. of reagent, and heat on water-bath 10 minutes. If cottonseed oil present, brown or even black color develops. Compare Million's test. Becker (PICROTOXIN) This reduces Fehling's solution when gently warmed with the latter. Bedot (FIXING DELICATE PELAGIC ANIMALS). Add suddenly a large quantity of 15- to 20-% cupric- sulphate solution to the sea water containing the animals, and as soon as latter are fixed add few drops nitric acid and leave for 4 or 5 hours. Harden by adding two volumes Flemming's "strong " solution to each volume copper solution, leave for 24 hours, then add few drops of 25-% alcohol, and during next 15 days add more alcohol gradually until strength of 70% attained. Use 90-% alcohol for definite preservation. Bedson (APOMORPHINE). On boiling morphine solution con- taining apomorphine with potassuim hydroxide, brown color develops. Behier (URIC ACID). See Babo's test. Behren (FATTY OILS). By treatment with a mixture of equal parts of sulphuric acid, sp. gr. 1.835 to 1.84, and nitric acid, sp. gr. 1.3, different oils behave differently. Sesame oil gives green color; olive oil, yellow. Beilstein (HALOGENS). Chlorine, bromine or iodine may be 1 m organic substances by a green or blue color on dip- pmg cupnc-oxide beads into suspected substance, and heating in lower part of Bunsen flame. Beissenhirtz (ANILINE). Solution of aniline in corrc. sulphuric TESTS AND REAGENTS. 17 acid acquires, when a grain potassium bichromate is added, first a red, then blue, gradually-disappearing color. Bela-von Bitto (ALDEHYDES AND KETONES). Fine greenish fluorescence is produced in few minutes on adding to suspected solution a few Cc. of aqueous or alcoholic solution (0.5- to i-%) of a meta-diamine salt. Fluorescence disappears on adding alkali and reappears on acidulating. Bela-Haller (MACERATING MIXTURE). Flacial acetic acid, i; glycerin, i; water, 2. Cells of central nervous system of mollusca show less shrinkage after macerating 30 to 40 min- utes in this than in other liquids. Bell, Carter (ALUM IN FLOUR OR BREAD). Fresh 5-% log- wood tincture in methylated spirit. Moisten 10 Gm. flour with water, then add i Cc. tincture and an equal quantity saturated ammonium-carbonate solution. Sample, if pure, gives pinkish color gradually fading to buff or brown. If alum present, a lavender or bluish tint develops, becoming more marked on drying. Bellamy (COPPER AND IRON). Tincture logwood affords blue color. Bellonci (NEUROLOGICAL METHOD). Treat material with 0.5- to i-% osmic-acid solut., hardening for 14 to 24 hours only; cut sections, and treat with 8o-% alcohol, then with ammonia. Benda (COPPER-HEMATOXYLIN). Harden material with chromic- acid or Flemming's solut., leave sections for 24 hours in 5-% neutral copper-acetate solut. at about 40 C., wash well with distilled water, and stain dark-gray or blackish in saturated aqueous hematoxylin. Decolorize sections in 0.2-% hydro- chloric acid till light-yellow, put back into copper solut. till bluish-gray, wash, dehydrate, clear, then mount in balsam. Benda (DOUBLE STAIN), Stain sections 24 hours in aniline- water safranine solut., then about half minute in solut. of 0.5 Gm. Lichtgrim F. S. or Saureviolett (Grubler) in 200 Cc. "" alcohol. Dehydrate, then mount in balsam. Benda (!RON-HEMATOXYLIN). Mordant sections 24 hours in following solution diluted with i or 2 vol. water: Ferrous sulphate, 80; water, 40; sulphuric acid, 15; nitric acid, 18. Wash well, place in i-% aqueous hematoxylin until quite black, wash again, and differentiate in 30-% acetic acid. 1 8 TESTS AND REAGENTS. Benysek (TUBERCLE BACILLI STAIN). Press sputum between two sterilized object-glasses, and expose to air (preferably under a bell- jar) to dry. Avoid heat, otherwise stain less dis- tinct. Now moisten dry sputum with mixture of cone, alco- holic solut. fuchsine, 4; carbolic acid, 5; and water 45, and warm gently over spirit lamp till vapors rise, then wash with water and stain with solut. methylene blue containing 10 per cent, sulphuric acid. Wash again after 4 to 6 minutes and dry. Tubercles are thus stained a dark-red, while rest of specimen is light-blue. Other bacteria not stained by this process. Bergman (MINERAL ACIDS). If wine or vinegar contains free mineral acid, calcium oxalate is not precipitated on adding 5 drops normal ammonium-oxalate solution, followed by 5 drops normal calcium-sulphate solution. Bergonzini (STAINING METHOD FOR PLASMA CELLS). Mix i vol. of acid-fuchsine solution (0.2-%) with 2 vol. methyl-green solut. (0.2-%) and 2 vol. gold-orange solution (0.2-%), and filter through cotton wool. The gold orange used must not pre- cipitate methyl green. Take sections from alcohol or corro- sive-sublimate solut.; wash with water, and stain for 3 to 4 minutes. Then wash with water for i or 2 minutes, immerse in absolute alcohol for 2 minutes, clear in bergamot oil or creosote, wash in turpentine, and mount in balsam. Berkley (MODIFIED WEIGERT'S STAINING METHOD). Harden sections of tissue not thicker than 2.5 Mm. for 24 to 30 hours in Flemming's solut. at 25 C. Then put in absolute alcohol, changed twice during first 24 hours; when sufficiently hardened imbed in celloidin and cut. Wash sections in water, immerse over night in satur. solut. copper acetate (or warm therein at 35 to 40 C. for half hour) then wash, and stain for 15 to 20 minutes in mixture of 2 Cc. satur. solut. lithium carbonate, 5 Cc. boiling water (boil 2 minutes), and 1.5 to 2 Cc. io-% hematoxylin solution. Warm stain to 40 C.; when sections cool, differentiate for i to 3 minutes in Weigert's ferricyanide liquid, diluted if necessary with one-third water. Then treat with water, alcohol, and bergamot oil, and mount in xylol balsam. Berlin (URIC ACID). See Babo. TESTS AND REAGENTS. 19 Berlinerblau (REGENERATING WEIGERT'S HEMATOXYLIN). Add 2.5 to 5% baryta water to used solution, shake well, and leave for 24 hours. Then pass in carbon dioxide, let stand 24 hours and filter. Bernouilly (ALCOHOL). Essential oils adulterated with alcohol form dense solutions on adding dry potassium acetate. Com- pare Barbier's test. Berthelot (ALCOHOL). Shake dilute solution of alcohol with few drops benzoyl chloride and soda-solution until odor of benzoyl chloride disappears characteristic odor of ethyl benzoate develops. Berthelot (PHENOL). Add a little sodium hypochlorite or solu- tion chlorinated lime to slightly ammoniacal liquid (urine) and warm blue color develops if phenol present. Acid changes color to red, and ammonia subsequently added re- stores original blue. Compare Bodde, Jacquemin, Lee, and Salkowski. Bertoni- Raymond! (NITROUS ACID IN BLOOD). Dialyse, evaporate dialysate to dryness, take up with hot alcohol, and add starch paste and potass, iodide blue color develops. Bertrand (ALKALOIDS). Silicotungstic acid, or a $-per cent, solution of one of its salts, gives precipitates with alkaloids. Reaction very delicate. Many precipitates give with oxidiz- ers characteristic color reactions. Bertrand (URic-Acio ESTIMATION). Add AgNO 3 to liquid containing uric acid in presence of an alkaline carbonate, col- lect pptd. silver, wash out any soluble silver salt present, treat with NH 3 , and weigh residual metallic silver, o.ooi Gm. uric acid = o. 001235 Gin. Ag. Berzelius (ALBUMIN). Fresh, cone, metaphosphoric-acid solu- tion precipitates all albuminous substances (except peptone) from their aqueous solutions. Berzelius (ARSENIC). Mirror is formed and alliaceous odor given off on heating arsenic in test-tube with charcoal. Berzelius (BROMIDES). Heat fragment with a bead of salt of phosphorus containing cupric oxide in blowpipe flame latter acquires bluish-green color. Berzelius (MUSK). Aqueous infusion of pure musk should not precipitate solution mercuric chloride. 20 TESTS AND REAGENTS. Betelli (FUSEL OIL). Mix alcohol, 5 Cc.; water, 6 Cc.; chloro- form, 15 drops. Shake well, and on standing, fusel oil in alcohol can be detected on evaporating separated chloroform. Bethe (METHYLENE-BLUE METHOD). Stain tissues of verte- brates and rinse in salt solution, place for 2 to 5 hours, accord- ing to size, in solut. of ammonium molybdate, i Gm. ; water, 10 Gm.; hydrogen dioxide, i *Gm. (For invertebrates use ammonium molybdate, i Gm.; water, 10 Cc.; hydrogen dioxide, 0.5 Cc.) This should be not more than 8 days old,, and is best cooled to o C. Subsequently wash in water for 0.5 to 2 hours, dehydrate in alcohol at o C., clear in clove oil or xylene, and imbed in paraffin or celloidin in the usual way. Bethe (STAIN FOR CHITIN). Place series of mounted sections on slides in fresh io-% aniline-hydrochlorate solut. (contain- ing i drop hydrochloric acid in each 10 Cc.) for 3 or 4 minutes, then rinse in water, and put slide with sections downwards in io-% potassium-bichromate solut. Repeat process if stain not sufficiently intense, but sections must be well rinsed with water after each immersion. Bettendorf (ARSENIC). Heat solution of stannous chloride in- cone, hydrochloric acid sp. gr. 1.19, with solution of arsenic or arsenous acids in strong hydrochloric acid. Brownish tur- bidity or precipitate of metallic arsenic and tin results. Pres- ence of much sulphuric acid, or of oxidizing or organic sub- stances, interferes with reaction. Betz (AMMONIA CARMINE). Make thick syrupy mass by rub- bing up commercial carmine with water and ammonia, with continual stirring, to effect solution. Add large quantity of water, after which filter solution and expose to sun in un- corked green glass bottle until precipitate is deposited. Ex- pose again, then filter, and repeat operation a third time. When no further precipitate deposited, the stain is ready for use. Betz (HARDENING FLUID). Mixture of equal parts sulphuric ether and alcohol. Used for hardening brain of insects prior to cutting sections. Bial (PENTOSE; GLYCURONIC ACID). The reagent is prepared from i to 1.5 Gm. orcine, 500 Gm. fuming HC1, and 25 to 30. drops i-% solut. Fe 2 Cl 6 . On heating urine with the reagent TESTS AND REAGENTS. 21 until bubbles begin to rise, a fine green color develops. Gly- curonic acid also gives the reaction, but much more Fe 2 Cl 6 is required. In this case employ a pinch of orcine to 2 or 3 Cc. of urine, and 4 to 5 Cc. fuming HC1, and add i to 2 drops io-% solut. Fe 2 Cl 6 . Bianco (CHROMO-ACETIC ACID). Add to concentrated acetic acid one-tenth its bulk of i-% chromic-acid solution. Bianco (NARCOTISING MIXTURE FOR ACTINIAE, ETC.). Gly- cerin, 20; alcohol (70-%), 40; sea water, 40. Pour carefully on surface of water containing the animals, and allow to diffuse quietly through it. Several hours may be necessary for this. Bickfalri (DIGESTION FLUID). Mix i Gm. dried stomach mu- cus with 20 Cc. of hydrochloric acid (0.5-%), and put into incu- bator for 3 or 4 hours, then filter. Macerate tissue in this % to i hour. Bieber (FIXED OILS). 5 vol. of a fixed oil with i vol. of a mix- ture of equal weights cone, sulphuric acid, fuming nitric acid and water. Color reaction occurs, varying with kind of oil. Bieber (PEACH KERNEL AND ALMOND OILS). With Bieber's reagent for fixed oils, peach-kernel oil gives deep orange color, while true almond oil forms yellowish zone. Biel (BENZENE AND BENZIN). These differ in behavior to iodine (color), alcohol (solubility), asphalt (solubility), nitric acid (nitrobenzene), and specific gravity. Biel (COCAINE TEST). Heat solution of o.i Gm. of a cocaine salt in i Cc. cone, sulphuric acid for several minutes on water- bath, and add several Cc. water. White, crystalline precipi- tate of benzoic acid forms. Bill (BROMIDES). Mixture of i drop each hydrochloric acid and gold- chloride solution with a bromide gives a yellow to dark orange-red color. Bill-Seligsohn (CINCHONINE). Acid salts of cinchonine (even in urine) give an amorphous precipitate with potassium ferro- cyanide, soluble on heating, but reprecipitated on cooling in form of acicular prisms. Biltz (looic ACID). lodic acid in nitric acid gives blue color on diluting acid with equal vol. water, adding few drops starch solution, and then few drops sulphuretted-hydrogen water. 22 TESTS AND REAGENTS. Biltz (SODIUM CARBONATES). Aqueous solut. pure sodium bicarbonate (1:15) gives white cloudiness when one-sixth its volume of aqueous solution mercuric chloride (1:20) added. If monocarbonate present, brownish-red precipitate falls. Binz (CARBON MONOXIDE IN BLOOD). Saturated, warm (40 C.) solut. tannic acid. Binz (QUININE IN URINE). Reagent consists of 2 parts iodine, i part potassium iodide, and 40 parts water, i Gm. quinine in 40 to 50 liters urine detected. Biondi (STAIN). See Ehrlich-Biondi. Bird (SULPHUR COMPOUNDS IN PETROLEUM). Prepare solut. of sodium plumbate by dissolving 1.5 dr. caustic soda in dis- tilled water to make 10 fl. drs., heating to boiling point, and while boiling adding litharge to saturation. Decant clear liquid from undissolved litharge. Shake well i fl. dr. of white petroleum oil to be examined, with 30 min. absolute alcohol, add 2 drops test solution, shake again for few seconds, and let stand for half hour. According to amount of sulphur present, the mixture assumes tint varying from deep orange with much sulphur, through orange and yellow to very pale yellow with traces only. Bischoff (BILIARY ACIDS). Heated with diluted sulphuric acid and cane sugar these yield red color. See also Pettenkofer and Strassburg. Bischoff (MELTING-POINT TEST FOR BUTTER). See Drouot's test. Bitto (ALCOHOLS, MONATOMIC). Methyl violet 0.5 Gm., water i liter. Shake i to 2 Cc. of this solution with 5 to 10 Cc. of the fluid to be tested and 0.5 to i Cc. potassium-sulphide solut. a monatomic alcohol develops a cherry-red to violet- red color. If no alcohols present, mixture becomes greenish- blue, precipitates reddish flocks, and finally appears yellow. Di- and poly-atomic alcohols, carbohydrates, acids, aromatic compounds, and phenols do not give the reaction. Bitto, von-Bela. See Bela-von Bitto. Bizzari-Bruno. See Bruno-Bizzari. Bizzozero (GENTIAN-VIOLET METHOD). Stain in Ehrlich's gen- tian-violet solut. for 5 or 10 minutes or longer; wash in alcohol TESTS AND REAGENTS. 23 5 seconds; in Gram's iodine solut. 2 minutes; alcohol 20 seconds; aqueous chromic-acid solut. (o.i-%) 30 seconds; alcohol 15 seconds; chromic-acid again 30 seconds; and alcohol 30 seconds. Afterwards treat with changes of clove oil until final decoloration, and mount in dammar. In another process by Bizzozero, treatment with iodine solution is omitted. Bjeloussow (ACACIA INJECTION MASS). Mix syrupy solut. acacia and saturated aqueous solut. borax, so as to have in the mixture i part borax to 2 parts gum. Add distilled water gradually to resulting mass, then force through fine-grained cloth, and repeat operation until a mass free from suspended gelatinous clots obtained. Bjorklund (CACAO BUTTER). 3 Gm. cacao butter should give a clear solution with 6 Gm. ether at 18 C. (otherwise wax present). Dip test-tube in water at o C. ; a cloudiness within 10-15 minutes indicates presence of foreign fats. Blachez (ALCOHOL). Alcohol in chloroform gives precipitate on adding small piece potassium hydroxide, agitating, pour- ing off chloroform after standing five minutes, shaking with equal volume water, then decanting latter and adding solut. copper sulphate. Blaise (QUININE). See VogeVs reaction. Blanc (FIXING INFUSORIA). For larvae of Echinodermata, Medusae, and Porifera, mix saturated solut. picric acid, 100; sulphuric acid, 2 ; water, 600. For Rhizopoda and Infusoria, add 2 to 3 drops of i-% acetic acid to every 15 Cc. of above mixture. Wash out with 8o-% alcohol, followed by 90-%, and absolute alcohol; then stain with tincture saffron (saffron, 5 Gm.; absolute alcohol, 15 Cc.), wash out with 8o-% alcohol, and pass through absolute alcohol into clove oil. Blanchard (STAINING BACTERIA). Treat cover-glass prepara- tion with osmic acid, placed in position on slide, and run under a drop of methyl- violet solut. After half an hour, complete preparation by running in glycerin or saturated calcium- chloride solut. tinted with methyl violet. If hematoxylm used as stain, it should be allowed to act 24 hours, and the preparation must then be washed repeatedly before mounting., Blarez (ANILINE COLORS). Shake 20 Cc. wine with 5 Gm,. 24 TESTS AND REAGENTS. lead peroxide for one minute; color due to natural coloring matter disappears, but aniline colors unaffected. Bloxam (ALKALOIDS). Distinctive color reactions are given by various alkaloids on dissolving in dilute hydrochloric acid and adding bromine water drop by drop. Bloxham (UREA). If a nitrate present add few drops ammo- nium chloride solution; if absent acidulate with hydrochloric acid. Evaporate to dryness in watch-glass and heat cau- tiously as long as thick white fumes evolved. Dissolve residue in a drop or two ammonia, add a drop barium chloride solut. and stir. If urea present crystalline streaks of barium cyan- urate will form in track of the rod. Blum (ALBUMIN). Dissolve 0.03 to 0.05 Gm. manganous chloride in little water acidulated with hydrochloric acid and treat with 100 Cc. io-% solut. sodium metaphosphate. Then add lead dioxide a little at a time, let liquid settle, and filter. Resulting pink solution of manganic metaphosphate detects albumin in urine. Place reagent in a test-tube and filter urine into it. Blum (HARDENING SOLUTION). Formaldehyde diluted with 10 vol. water. Blyth (LEAD). Lead in potable water precipitates coloring matter on adding tincture cochineal (i-%). Boas (HYDROCHLORIC ACID). Solut. i Gm. resorcin and 3 Gm. cane sugar in 100 Gm. alcohol (50-%) gives red color on adding one drop to a solution containing free hydrochloric acid, and evaporating to dryness. Compare Conrady's test. Boas (LACTIC ACID). Test for lactic acid in gastric juice depends on oxidation of the acid to aldehyde and formic acid by action of sulphuric acid and manganese. The alde- hyde detected by addition of Nessler's reagent or by formation of iodoform when iodine solution added. This test for lactic acid more delicate than that of Uffelmann, (q. v.). Boas (REAGENT). Tropaeolin solution, or paper saturated with such solution. Boas (TEST PAPER). Tropaeolin Paper. Paper impregnated with tropaeolin OO gives with alkalies a yellow, with acids a red, color. Also known as Lutke's paper. Bobierre (LEAD). Lead in tin gives yellow stain on applying a TESTS AND REAGENTS. 2 5 drop glacial acetic acid, heating, and adding a drop potas- sium-iodide solution (5-%). Boccardi (SOLUTION), i. Oxalic-acid solut. (o.i- to 0.3-%). 2. Formic acid, 5 Cc.; oxalic-acid solut. (i-%), i Cc.; water, 25 Cc. Bodde (DIFFERENTIATING RESORCIN AND PHENOL, BENZOIC AND SALICYLIC ACIDS). Resorcin solut. yields violet color with sodium hypochlorite, changing to yellow; with more hypochlorite and heat, a yellowish-red to brown. If ammo- nia added before addition of hypochlorite, a violet first ensues, changing to yellow, and, on boiling, liquid becomes dark green. Phenol, salicylic acid, and benzoic acid yield a slight color with hypochlorite only on heating. On previous addition of ammonia the carbon acids are not colored, but phenyl yields a greenish-blue. Boedecker (ALBUMIN). With albumin (e. g., in urine) acidu- lated with acetic acid, potassium ferrocyanide causes turbidity or flocculent precipitate. Boedecker (SULPHITES). Sulphites in neutral liquids give with zinc- sulphate solut. and little sodium nitroprusside, a rose to dark-red color. Potassium ferrocyanide gives purple pre- cipitate. Boehm (BOMBAY MACE). Filter alcoholic extract of Bombay mace through pure white filter-paper paper only stained pale-yellow color, and when dried, red color of Bombay mace appears round the edge. Boehmer (HEMATOXYLIN). i. Add 2 or 3 drops i-% hema- toxylin solut. in absolute alcohol to a v/atch-glassful of aqueous solut. alum (0.5-%), leave sections in the mixture half to i day, then pass in succession through absolute alcohol, alcohol solut., tartaric acid, absolute alcohol again, then through benzene or turpentine. Finally mount in castor oil. 2. Dissolve (a) crystallized hematoxylin, i Gm., in absolute alcohol, 10 Cc., and (b) ammonia alum, 10 Gm., in distilled water, 200 Cc. Mix and allow to ripen some days before use. Filter after standing a week. Wash out with aqueous alum solut. (0.5-%) or with acids. Boehn (NEUTRAL CARMINE). Triturate 3 or 4 Gm. carmine 26 TESTS AND REAGENTS. and 200 Gm. of water; add ammonia drop by drop, until the solution acquires a cherry-red color. Then add acetic acid until solution sealing-wax red in color and filter. To inten- sify color add 2 drops ammonia before filtering, and expose in open vessel until odor of ammonia gone. Stain tissues in this, for 24 hours (or longer if more than i Mm. thick), after which wash out with mixture of equal parts glycerin and water,, acidulated with 0.5-% hydrochloric acid. Boernstein (SACCHARIN). Extract substance with ether, and heat extract, after ether removed by distillation, with resorcin and sulphuric acid, and add excess of soda solution. If saccha- rin present, a strong fluorescence develops. According to Hooker, other substances, e. g., succinic acid, also give this reaction. Boettger (ALCOHOL). Alcohol gives blue color with solut. mo- lybdic acid in sulphuric acid. Alcohol present in essential oils can be removed by shaking with glycerin. Or, a piece of dry potassium hydroxide added to the oil is soon covered with a yellowish film. Boettger (AMMONIA). Gaseous ammonia changes the color of alkanin paper from red to blue. Boettger (ANIMAL FIBER). Treat fabric with alcoholic solution rosolic acid, then with soda solution, and wash. Animal fibers (as wool) are dyed red, linen (flax) pink, but cotton remains uncolored. Compare with Liebermanris test. Boettger (CARBON MONOXIDE [COAL GAS]). Fabrics impreg- nated with a palladium-chloride solut. are rapidly blackened on exposure to coal gas. Ethylene, methane, and hydrogen sulphide afford a similar reaction. Boettger (COLORING MATTERS OF RED WINE). Mix i vol. cone, copper-sulphate solut. with 3 vol. wine diluted to ten times its volume. Pure red wine is thereby discolored. Un- fermented wine, as well as coloring matter of huckleberries, malva, and cherries, and fuchsine, remain unchanged or are colored violet. Boettger (COTTON AND LINEN FIBERS). Dye fabric with fuch- sine solution, wash out with water, then treat with ammo- nia. Cotton is decolorized; flax retains the dye. See Lieber- mann's test. TESTS AND REAGENTS. 27 Boettger (ERGOT IN RYE-FLOUR). Heat several minutes with equal bulk ether and few crystals of oxalic acid reddish color develops. Boettger (FLOUR IN STARCH). Flour in starch gives more or less persistent foam on boiling i Gm. of the mixture with 180 Cc. water, and stirring briskly with a glass rod. Boettger (GLUCOSE). Boil dilute glucose solution (or diabetic urine) with sodium-carbonate solut. and some bismuth sub- nitrate or bismuth oxy hydrate. Reduction causes blacken- ing of suspended bismuth. According to Krueger, a stable reagent can be prepared by heating 15 Gm. bismuth nitrate, 15 Gm. tartaric acid, 75 Gm. water, sufficient potassa lye to effect solution, and some glycerin. Boettger (HYDROGEN DIOXIDE), i. To a solution containing hydrogen dioxide add some cadmium-iodide, and starch- paste, containing also a little ferrous sulphate; blue color (starch iodide) develops. (Also known as Schoenbein's reagent.) 2. Heat liquid containing hydrogen dioxide with few drops ammoniated silver-nitrate solut. containing no free ammonia ; cloudiness caused and silver is reduced. Boettger (INDICATOR). Color of tincture Coleus verschaffelti is changed from red to green on adding to an alkaline solution. Boettger (MANGANESE). Red color develops on throwing a little manganese into fused potassium chlorate. Boettger (NITRIC ACID). Nitric acid in potable water gives a red to brownish-red color on mixing 3 drops of the water, with two drops brucine solution, and 3 or 4 drops sulphuric acid. Boettger (NITROUS ACID). Nitrous acid gives blue color on adding diluted sulphuric acid and cadmium-iodide starch paste. See Boettger' s reagent. Boettger (OZONE). Filter-paper saturated with gold-chloride solution, free from acid, is colored violet by ozone. A test- paper formerly suggested by Boettger contained thallium hydroxide,' which was colored brown by ozone. Boettger (REAGENT). Solution of cadmium iodide and starch. Dissolve starch, i, in water, 200, and hydrochloric acid, i. Neutralize with calcium carbonate, 10; then add sodium s g TESTS AND REAGENTS. chloride, 10; and cadmium chloride, 0.5, and make up to 250 with water. Boettger (SAFRANINE). With sulphuric acid safranine turns blue, and subsequent addition of water changes color to green. Boettger (STAINING METHOD). Treated preparations with Muller's fluid, then alcohol, then stain with rosaniline nitrate dissolved in glycerin and water, wash out with alcohol, clear with creosote or clove oil, and finally mount in balsam. Boettger (SUGAR IN GLYCERIN). Heat 5 drops glycerin to boiling with 100 drops water, i drop nitric acid, sp. gr. 1.3, and 0.03 to 0.04 Gm. ammonium molybdate. Sugar colors solution intensely blue. Boettger (SULPHOCYANIDES). Filtering paper dipped in tinc- ture guaiac and dried, then moistened with copper-sulphate solution (1:2,000), is colored blue by sulphocyanides in solution. Boettger (TEST-PAPER), i. Anchusin Paper. Gives with alkalies a green to blue color; with acids a red. 2. Colein Paper. Gives with alkalies a yellow color, and with acids a red. Boettger (WATER IN ETHER). Ether containing water causes a milky appearance on shaking gently with an equal bulk carbon bisulphide. Bogomolow-Wassilieff (ALBUMIN AND PEPTONES), i. Car- minic acid precipitates albumin (either egg or in urine) even in very dilute solutions (1:9,000). Also precipitates proteo- albumoses and deutero-albumoses. The latter change color of carminic-acid solut. (33-per cent, aqueous) to black, and precipitate does not dissolve on boiling; former simply darken it, and the ppt. dissolves on boiling. Albumoses insol. in water give reddish- violet color with carminic-acid solut. 2. Precipitate any accompanying albuminoids with tri- chloracetic acid. Peptone revealed in filtrate by biuret reaction. See Devoto's reaction for peptone. Bohland (URINARY DEPOSITS). To preserve urinary deposits, decant supernatant urine, wash residue with physiological salt solution (sodium chloride, 4; sodium carbonate, 3; water, 1,000), then treat with Muller's solution, renewing this 3 or 4 TESTS AND REAGENTS. 29 times in 14 days. Finally harden with alcohol, frequently renewed until colorless. Bohlig (AMMONIA). a. Mercuric chloride, i; water, 30. 6. Potassium carbonate, i ; water, 50. Free ammonia and its carbonate cause white turbidity with solution a. If reac- tion is first induced on addition of solution b, the ammonia is combined with other acids. Bolas (NITRIC ACID). Mix 10 parts sulphuric acid with i of ferrous-sulphate solution, heat, and carefully overlay on suspected liquid. Nitric acid causes brown zone. Bollet (CASTOR OIL). Heat 10 Gm. of the oil with 6 Gm. alco- hol solut. silver nitrate (silver nitrate, 5 Gm.; nitric acid, i Gm. ; alcohol, 100 Gm.) five minutes on a water-bath after thorough mixing if cottonseed oil present a reddish color develops. Bolley (BUTTER). Butter exposed to sunlight in contact with a moistened strip of blue litmus paper reddens the latter;, artificial butter does not. Bolton (INDICATOR). Polysulphide solution a very cone, solut. of sublimed sulphur in a solut. of an alkaline sulphide. Gives with alkalies no ppt.; with acids, however, a turbidity (pptd. sulphur). Bonastre (MYRRH). Saturate strips of filter-paper with tinc- ture myrrh, dry, and wet with a drop nitric acid. Genuine myrrh causes a violet color. Bonne (MACERATION FLUID). Mix io-% sodium-chloride solu- tion, 5, with absolute alcohol, i. Born-Wieger (QUINCE MUCILAGE). Mix 2 vol. quince mucilage and i vol. glycerin and add trace of carbolic acid. Used to fix serial sections to slides, gentle heat being applied for that purpose. Bornstein (SACCHARIN). Extract substance with ether, distil off solvent, and heat residue with resorcin and concentrated sulphuric acid. Saccharin produces a marked fluorescence on saturating with caustic soda. Borntraeger (ALOE REACTION). Shake alcoholic extract aloes with benzin. To benzin solution, after separation from alco- holic layer, add small amount strong ammonia water, and gently heat while shaking. Aloes (also other substances,. 30 TESTS AND REAGENTS. such as rhubarb, curcuma, galls, catechu) effect a violet col- oration of ammoniacal solution. Borntraeger (INDICATOR). Concentrated tincture of fresh orange peel, shaken with ether, is not affected by acids, but turns lemon-yellow with alkalies. Borodin (SOLUBLE PRECIPITATES). Process consists in treat- ing precipitate with a saturated solution of the body with which it is supposed to be identical. E. g., a vegetable mi- croscopical preparation, containing a substance, suspected to be asparagin, is treated with a saturated solution of that body. If it be asparagin, it will be insoluble; if not, it will probably be dissolved. Borsarelli (ALCOHOL). Heat essential oils containing alcohol with dry calcium chloride a dense solution is formed. Bouchardat (ALBUMIN). 3.32 Gm. potassium iodide, 1.35 Gm. mercuric chloride, 20 Cc. acetic acid, and water to make 60 Cc. Solut. precipitates albumin in urine. Also precipitates uric acid, mucin, and alkaloids. Uric-acid ppt. more soluble, especially on heating, hence test in well diluted urine. Mucin ppt. is light and cloudy albumin ppt. is flocculent. Alkaloid ppt. soluble on warming and in alcohol. Bouchardat (ALKALOIDAL REAGENT). Dissolve 10 Gm. iodine and 20 Gm. potassium iodide in 500 Gm. water. With aqueous solution of most alkaloids reagent yields reddish- brown precipitates. Boudart (DIFFERENTIATING FATTY OILS). Mix oils with nitric acid, sp. gr. 1.45 to 1.50. A carmine-red coloration gradually produced by genuine cod-liver oil. Boudet (OLIVE OIL). Note color produced on adding 3 parts of mixture of equal volumes sulphuric and nitric acids to 10 parts of the oil; and solidification caused by addition of 5-% fuming nitric acid to oil. Bougault (ARSENIC IN GLYCERIN). Dissolve 20 Gm. of so- dium hypophosphite in 20 Cc. of water, add 200 Cc. of cone. HC1 (sp. gr. 1.17), filter through cotton, and mix 10 Cc. reagent with 5 Cc. glycerin to be tested. On now heating the mixture on a water-bath, a flocculent brown ppt. or dark- brown color develops if but o.oooi Gm. arsenous acid is TESTS AND REAGENTS. 31 present. Even 0.00002 Gm. still gives a distinct brown color, while o.ooooi may still be detected. Bourget (IODIDES IN URINE AND SALIVA). Impregnate filter-paper with a 5 -per cent, starch solut., dry, and cut into squares of 5 Cm. each. Then drop 2 or 3 v drops of a 5 -per cent, ammonium-persulphate solut. in the center of each square, and dry pieces in the dark. Prepared paper gives even with traces of iodine an intensely blue color. Reaction visible in solution containing 0.00005 P er cent. KI. Bourgoin (NITROBENZENE). Shake 15 drops essential oil bit- ter almonds with 8 drops potassa solut. ; green color devel- ops if nitrobenzene present; on subsequently adding 20 drops water two layers form the upper green, the lower yellow. .Bourne (BORAX CARMINE). Mix saturated solution of carmine in 4-% borax solution with equal volume of 70-% alcohol. Let mixture stand a week, then filter; if carmine deposited subsequently, filter again. Leave tissues in this stain for i to 3 days, according to size, then immerse in acidulated alcohol for 3 to 6 hours until bright and transparent. Bourreau (ALBUMIN). See Rock's reagent. Boussingault (NITRIC ACID). Depends on decolorization of indigo solution in sulphuric acid in presence of hydrochloric acid. Heat a little of the latter in test-tube, add a few drops of very dilute indigo- sulphate solution, then the substance to be tested. Nitric acid discharges blue color. Boutmy-Brouardel. See Brouardel-Boutmy. Bouvier (AMYLIC ALCOHOL). Alcohol containing fusel oil ac- quires a yellowish color on adding a few crystals potassium iodide and agitating gently. Braconnot (ARSENIC). Extract arsenic with alcohol and test with sulphuretted hydrogen. Bradford (OLIVE OIL). Reddish color on shaking olive oil with solution of lead subacetate indicates presence of cotton- seed oil. Brady (CHLORAL-HYDRATE MEDIUM). Strong, aqueous chloral- hydrate solution. Braeutigam-Edelmann (HORSE MEAT). Boil 50 Gm. of meat to be tested with 200 Gm. water for i hour. Evaporate fil- tered broth to one-half its volume, remove albumin by means 32 TESTS AND REAGENTS. of dilute nitric acid, and add iodine water to form a layer.. Horse meat, on account of its large percentage of glycogen, causes a burgundy-red zone. Starch and dextrin interfere with the reaction, the former giving a blue, the latter a red color. Brand (ABRASTOL IN WINE). Treat wine first with lead per- oxide and sulphuric acid to eliminate other coloring matter, then shake out with chloroform, and evaporate solvent; abras- tol is left and may be identified by green color reaction with sulphuric acid. Brand (FLUORINE IN BEER). Modification of Niviere's test (q. v.). Convert fluorine in the precipitate into hydrofluoric acid by adding sulphuric acid; then identify by its etching properties. For details see "Zeitschr. f. d. ges. Brauwesen," 1895, p. 317. Brand (THALLEIOQUIN REACTION), i. Triturate salts of quinine or quinidine with a little chlorine water, and add ammonia; green color develops. If to solution of alkaloids, after addi- tion of a slight excess of chlorine water, ammonia water is added drop by drop, a green, flocculent precipitate forms, soluble with green color in excess of ammonia water. 2. Hyde's modification consists in acidulating a quinine solution containing 5 Mg. of the alkaloid, with one drop sul- phuric acid (1:4), passing through a small filter and adding chlorinated-lime solution until bluish fluorescence first visible is destroyed. A few drops dilute ammonia (1:3) are now added; if quinine present, a bright green color develops, changed by dilute sulphuric acid to red. Brandberg (BENZENE; BENZIN). Pitch dissolves in benzene, but not in petroleum spirit. Brandt (GLYCERIN JELLY). Soak 2 parts gelatin in water, till soft, then drain, melt, add 3 parts glycerin, and filter. Branson (ASSAY OF GOLD CHLORIDE). Dissolve 15 grains of the salt in water, add 25 Cc. of normal oxalic acid solut., set aside for 36 hours at about 21 C. and expose to light for 12 hours, then boil, collect precipitate, dry, incinerate and weigh the metallic gold. Brantlecht (POTABLE WATER). To detect organic impurities in potable water, treat 100 Cc. with 5 drops aluminium-sul- TESTS AND REAGENTS. 33 phate solution (aluminium sulphate, i ; hydrochloric acid, i ; water, 8), and add i or 2 drops ammonia. Filter off precipi- tate, dissolve it in 10 or 15 drops diluted acetic acid, and examine under the microscope before and after addition of safranine. Brass (ALCOHOLIC CARMINE). 70-% alcohol, 100 Cc.; hydro- chloric acid, 15 drops; carmine, an excess. Braun (CHLORATES). Chlorates yield cherry-red color on adding solution of aniline sulphate containing toluidin and hydro- chloric acid. On neutralizing, color changes to blue. Braun (GLUCOSE). Glucose solution heated with a few drops picric-acid solution (1:250) gives a deep red color. Creati- nine gives a similar reaction with picric acid, and so does ace- tone, but weaker color. Braun (MOLYBDIC ACID). Aqueous solution potassium ethyl- sulpho-carbonate gives a yellow to flesh-colored precipitate, which soon becomes violet, on adding to a very dilute solution of molybdic acid containing a little nitric acid. Braun (NICKEL). A rose-red to deep brownish red color, almost black, results on adding solution of potassium sulphocarbonate to a solution containing nickel. Braun (NITRIC ACID), i. Addition of first a small quantity aniline sulphate, then cone, sulphuric acid, to solution of a nitrate (or of free nitric acid) produces violet-blue color. 2. Add to i Cc. sulphuric acid, drop by drop, 0.5 Cc. aniline- sulphate solution (10 drops aniline and 50 Cc. diluted sul- phuric acid). Place some reagent on a porcelain plate and draw through it a glass rod dipped in suspected liquid. Ni- tric acid present causes a reddish fringe on breathing upon surface of the mixture. Breinl (SESAME OIL). HC1 and aldehydes of aromatic series give various color reactions. Shake 10 Cc. oil for half minute with o.i Cc. aldehyde solut. and 10 Cc. cone. HC1 with benzoic aldehyde an orange color forms; with vanillin, piper- onal, or orthoxybenzoic aldehyde a reddish- violet color de- velops, even in solut. containing 0.5-% oil. Bremer (GLUCOSE IN BLOOD). Mix equal volumes saturated solutions eosin and methylene blue, collect precipitate, dry, finely powder, and mix with i-24th its weight of eosin andi 34 TESTS AND REAGENTS. i-6th of methylene blue. When required for use 0.02 to 0.05 Gm. of mixture are dissolved in alcohol (33-%), 10 Gm. Im- merse a cover-glass with a drop of the blood to be examined in solution for 4 minutes. Glucose causes a blue-black color. Bremer (GLUCOSE IN URINE). Introduce 10 Cc. normal and diabetic urine respectively into two test-tubes, and place a small pinch of Gentian Violet B, Merck, on surface of liquid in each tube so as to avoid having any of the powder touch the side of the tubes. In normal urine the violet floats on the sur- face and gives off little clouds and threads which disappear on slight agitation, fine particles falling to the bottom. Diabetic urine is colored in a few seconds, from surface downwards, a blue or bluish- violet, permanent on agitation. The more sugar present, the deeper the color. If methylene blue is used, normal urine is colored green; diabetic urine blue. Bremer (SESAME OIL). To a cooled mixture of 50 Cc. absolute alcohol and sulphuric acid add 10 drops furfurol. When one drop of reagent is stirred with sesame oil (or with margarine containing it) a red color develops in i or 2 minutes. Pure butter and albuminoids are not colored. Compare Villa- vecckia and Fabrics reagent. Bretet (DIFFERENTIATING GLUCOSE FROM SACCHAROSE OR LEVULOSE IN URINE). Precipitate obtained by interrupted boiling with Fehling's solut. readily and rapidly settles; that afforded by saccharose or levulose acquires a yellowish to red- brown color, and remains suspended for a long time. Brieger (PYROCATECHIN). Add one drop of urine to i drop very dilute ferric-chloride solut. on watch-glass pyrocatechin causes an emerald-green color; on adding now a dilute solut. sodium bicarbonate, or ammonium carbonate, fluid becomes violet, changing back to green with acetic acid. Brieger (STRYCHNINE). Pure chromic acid gives a violet color with strychnine. Brissemoret (ALKALOIDS OF OPIUM). With Keller's reagent (cone. H 2 SO 4 containing a trace of Fe); with cone. H 2 SO 4 containing a trace of NO; and with pure H 2 SO 4 , various color reactions are obtained. For details of the reactions see MERCK'S REPORT, ix, p. 322. Bristol (REGENERATING OSMIC-ACID SOLUTIONS). Add 10 to TESTS AND REAGENTS. 35 20 drops fresh hydrogen dioxide solution to each 100 Cc. of i-% osmic-acid solut. Brosicke (STAINING METHOD). Treat tissues with i-% osmic- acid solut. for i hour, then wash out carefully and immerse for 24 hours in cold saturated aqueous oxalic-acid solution. Tissues should not be allowed to blacken in the osmic-acid bath. Brouardel-Boutmy (DIFFERENTIATING PTOMAINES AND PLANT ALKALOIDS), i. With potassium ferrocyanide and ferric chloride ptomaines produce a blue color. 2. Characters are written with a quill on silver-bromide paper, using solution of the alkaloid or ptomaine. The paper, after laying aside for half-hour, protected from light, is developed with hyposul- phite. Ptomaines yield black characters; plant alkaloids do not. (Morphine also yields reaction i. compare Kieffer's reaction in fact none of the above reactions, depending on reducing properties of ptomaines, can be considered charac- teristic.) Brown (COPPER). Treat copper salt in solution with excess of potassium iodide cuprous iodide precipitated. The iodine in latter determined with standard solution sodium thio- sulphate. Bruecke (BERLIN-BLUE INJECTION MASS). Wash precipitate resulting on adding aqueous solut. of ferric chloride (5-%) to aqueous solut. potassium ferrocyanide (io-%) till water begins to run off blue, then dry. Or, mix io-% ferric-chloride solut. and 20-% potassium ferrocyanide separately with twice their volume of a cold saturated solut. sodium sulphate, then mix as before. In either case a cone, solut. is made of the washed and dried Berlin blue, and just sufficient gelatin added to form a jelly when cold. The injection should be used at 60 C., and injected material must be hardened in 94-% alcohol. Clear sections with resinous turpentine, prepared by exposure to air in large vessels, stain with carmine if desired, and avoid glycerin for mounting. Bruecke (BILIARY PIGMENTS IN URINE). Boil with diluted nitric acid, then add cone, sulphuric acid a green color chang- ing to blue develops. Detects bile if 7.5 per cent, of latter present. See Gmelin's test. 36 TESTS AND REAGENTS. Bruecke (BIURET REACTION FOR ALBUMINOIDS). Coagulated albumin acquires a handsome violet color when treated first with diluted copper-sulphate solut., then, after the excess is. removed, with dilute soda solution. Comp. Rose's biuret reaction. Bruecke (DIGESTION FLUID). Glycerinated extract pig's stom- ach, i vol.; hydrochloric acid (0.2-%), 3 vol.; thymol, a few crystals. Bruecke (GLUCOSE). Boil 5.5 Gm. freshly precipitated, moist bismuth subnitrate for 10 minutes with a solut. 30 Gm. potas- sium iodide in 100 Gm. water, then add 5 Gm. (25-%) hydro- chloric acid. Glucose (diabetic urine) effects reduction and causes a brown or black color. Bruecke (PROTEIDS). Saturate boiling io-% potassium-iodide solution with freshly precipitated mercuric iodide, and filter when cold; in solutions acidulated with hydrochloric acid, proteids are precipitated on the addition of reagent. Com- pare Tanrefs reagent and Oliver's test-paper. Bruecke (RED INJECTION FLUID). A concentrated solut. po- tassium ferrocyanide is followed by a similar solution of copper sulphate. Bruecke (UREA). Crystalline deposit obtained on heating alco- holic extract with a little amylic alcohol, filtering and adding solution of oxalic acid in amylic alcohol. Brulle (FOREIGN OILS [COTTONSEED OIL] IN OLIVE OIL). Boil 10 Cc. of the oil with o.i Gm. powdered albumin and 20 Cc. nitric acid. When albumin is dissolved, pure oil is almost colorless, and, on cooling, of a turbid, straw-yellow color. Color permanent after 24 hours, and liquid solidifies. Cottonseed oil causes liquid to become orange to brownish- red on solution of albumin, and no solidification takes place. Brun (GLUCOSE MEDIUM). Dist. water, 140; glucose, 40; gly- cerin, 10 ; camphorated spirit, 10. Filter to remove excess of camphor. Brunner (DiAzo REACTION). a. Para-amido-acetophenone, 0.5 Gm. ; hydrochloric acid, 50 Gm. ; distilled water, i ,000 Gm. b. Sodium nitrite, 0.5 Gm.; distilled water, 100 Gm. For use mix 100 Gm. a with 2 Gm. b. Place 10 Gm. of this mix- ture and an equal quantity urine in a test-tube, and add 2.5 TESTS AND REAGENTS. 37 Gm. of lo-per cent, ammonia water in certain febrile dis- eases (e. g. typhoid) a ruby-red develops. Brunner (GLUCOSIDES). On heating with bile and sulphuric acid they produce a red color (reversed Pettenkofer's re- action). Brunner (NITROBENZENE). Red color is produced on adding potassa solution, alcohol and a little sulphur to nitrobenzene. Brunner (PiCRic ACID). A woolen thread immersed in liquid containing picric acid, then rinsed lightly in water and ex- tracted with ammonia, is colored red by potassium-cyanide solut. Brunner (SULPHUR). Reddish color obtained on mixing sul- phur with potassa solut. and adding few drops of nitroben- zene and alcohol to the mixture. Bruno- Bizzari (GLUCOSE). Strips of white woolen material dipped in a io-% aqueous stannous-chloride solut. and dried. Drop a few drops diabetic urine on prepared material and heat decided dark spot appears. Test may be made quan- titive by comparing spot with one caused by a glucose solut. of i or 2 : 200, or other known strength. Brunotti (GELATIN IMBEDDING MASS). Dissolve 20 Gm. gela- tin in 200 Cc. dist. water with heat, filter, and add 30 to 40 Cc. acetic acid and i Gm. mercuric chloride. Buchheister (OLIVE OIL). Test depends on color reactions following addition to olive oil of equal parts nitric and sul- phuric acids. See also Boudet's test. Buchner (JALAP; SCAMMONY). Dissolve jalap and scammony resins in diluted potassa or soda solution, then heat and filter; no precipitate and only a slight opalescence should be caused by diluted sulphuric acid in excess. Buckingham (ALKALOIDS). Freshly prepared solut. of i Gm. ammonium molybdate in 16 Gm. cone, pure sulphuric acid heated till solution is clear. Reagent yields precipitates of different colors with various alkaloids. "Comp. Hager, Pharm. Praxis," 1886, I. p. 204. .Budge (ASPHALT INJECTION MASS). Cover asphalt with ben- zene, and let stand several days; then preserve for use. Before injecting, add 30 to 50% benzene, and filter. Chloro- form or turpentine may be used instead of benzene. 38 TESTS AND REAGENTS. Bujwid (ARSENIC). A culture of the mold Penicillium brevi- caulis, grown upon potato at 37 C., gives rise to a strong alliaceous odor in presence of such minute traces of arsenic as. would scarcely respond to Marsh's test. Bujwid (NITRITES). Dilute an alcoholic solution of indol (i or 2 : 16,000) with water. On adding a few drops of this solut. to- 10 Cc. water heated with a few drops hydrochloric acid (free from nitrites) to 7o-8o C., a fine red color develops if water tested contains nitrites. Bujwid- Dunham (PRODUCTS OF ASIATIC CHOLERA BACILLUS). See PoehVs reaction. Bunge (STAINING FLAGELLA). Mordant with mixture of 3, parts aqueous solut. tannin, and i part aqueous i : 20 ferric- chloride solution, adding to each 10 Cc. i Cc. of saturated aqueous solut. fuchsine. Treat with mordant for 5 minutes,. then wash and stain with Neelson's solution. Bunger (HARDENING FLUID FOR MICROSCOPIC SECTIONS). Chromic-acid solution (i-%), 25; osmic-acid solut. (i-%), 10; acetic acid (i-%), 20; water, 45. Bunsen (PHOSPHORIC ACID). Phosphoric acid in minerals is indicated by formation of phosphoretted hydrogen on fusing the minerals with sodium and moistening with water. Burchard (CHOLESTERIN AND CHOLESTERIN FATS). Dissolve substance in chloroform, then add acetic anhydride and a few drops sulphuric acid a violet to green color develops. Burgess (CITRAL AND OTHER AROMATIC COMPOUNDS). Dis- solve 10 Gm. mercuric sulphate in 25-% H 2 SO 4 to make 100 Cc. Vigorously shake 2 Cc. of substance with 5 Cc. of re- agent, and note color after 10 minutes. Citral yields a bright- red color on shaking, which disappears rapidly with formation of a whitish compound. Citronellal gives a bright-yellow on* shaking, and remains for some time. Limonene gives an evanescent faint flesh color. Linalyl acetate gives a brilliant permanent violet. Linalol gives a deep- violet quickly, and Eugenol affords a light- violet. Caryophylline gives a yellow- ish compound. For details see MERCK'S REPORT, x, p. 86. Busch (DECALCIFICATION OF BONE). Dilute i vol. pure nitric acid (sp. gr. 1.25) with ten vol. water, for decalcifying large' and tough bones; for young bones dilute to i %. Treat bones TESTS AND REAGENTS. 39 with 95-% alcohol for 3 days, then in the nitric acid for 8 to 10 days, the latter being changed daily. When decalcifica- tion complete, wash for i or 2 hours in running water, then immerse in 95-% alcohol, which should be changed after a few days. Young and fetal bones may be treated first with solut /containing i% potassium bichromate and 0.1% chromic acid; then decalcified with i- or 2-% nitric acid, to which i% potassium bichromate or o. i % chromic acid has been added. Then place in alcohol. Busch (STAINING BONE). Stain sections of decalcified bone for 5 or 10 minutes in weak aqueous eosin solut., which may be preceded or followed by hematoxylin, then dehydrate in absolute alcohol, and mount without cleaning in benzene- balsam. Busse (BOMBAY MACE). Immerse strips of white filter-paper in alcoholic extract of the mace for 30 minutes, then plunge in saturated baryta water quickly heated to boiling; remove and dry on filter-paper. With Bombay mace the dry strips assume a bright red; true Banda mace gives a brownish yel- low, the under side of the paper being pale reddish brown. Papua mace gives colors resembling the Banda variety, but less intense. Busse (CELLOIDIN SOLUTIONS). Three successive baths are prepared by dissolving 10 parts celloidin in 150, 105 and 80 parts respectively of a mixture of equal parts ether and abso- lute alcohol. See Elsching's solution. Butschli (Acio HEMATOXYLIN). Dilute Delafield's solution and add enough acetic acid to decidedly redden it. Butschli (IMBEDDING METHOD). Pass directly from chloroform into chloroformic paraffin solution, then evaporate chloroform at melting-point of paraffin. Butschli (IRON HEMATOXYLIN). Treat sections with weak aqueous solut. ferric acetate, wash with water, and stain in 0.5 -per cent, aqueous hematoxylin solution. Cadet (ARSENIC). The characteristic odor of cacodyl develops on heating with sodium acetate. Cadier (ALBUMIN). Same as Tanret's reagent (q. v.). Cailletet (COPPER IN OILS). Shake 10 Cc. of oil with a solu- 40 TESTS AND REAGENTS. tion of o.i Gm. pyrogallic acid in 5 Cc. ether copper causes a brown color and turbidity. Cailletet (FATTY OILS). 12 parts of phosphoric acid sp. gr. 1.44; 7 parts sulphuric acid sp. gr. 1.84; and 10 parts nitric acid sp. gr. 1.37. According to other authorities it is a nitric acid containing nitrous acid. Cailletet (TARTARIC AND CITRIC ACIDS). Pour a saturated solution of potassium bichromate on a crystal of the acid. Pure citric acid slowly develops a brownish zone; if tartaric acid present the color is violet or black. Caillian (GLUCOSE). On shaking urine with half its volume of chloroform, and allowing to stand, any glucose present will be found in the upper layer. Calberla (GLYCERIN MIXTURE). Equal parts glycerin, alco- hol, and water. Keep fixed objects in the mixture till re- quired for dissection or section cutting. Calberla (!NDULIN STAIN). Dilute a cone, aqueous solut. of indulin with 6 vol. of water and stain sections 5 to 20 minutes. Then wash in water or alcohol and examine in glycerin or clove oil. Calberla (MACERATING MIXTURE). Potassium chloride, 0.4 Gm. ; sodium chloride, 0.03 Gm.; sodium phosphate, 0.2 Gm.; calcium chloride, 0.2 Gm.; water impregnated with carbon dioxide, 100 Gm. Mix i vol. of this solut. with half a vol. of Muller's solut., and i vol. water. The Miiller's solut. may be replaced by a 2. 5 -per cent, solut. ammonium chromate. Nerve and muscle tissues of embryos* are macerated in this mixture, then isolated by teasing and shaking; specimens are finally mounted in cone, solut. potassium acetate. Calberla (METHYL-GREEN AND EOSINE). Dissolve eosine i, and methyl green 60, in warm 3o-per cent, alcohol. Stain sections in this for 5 to 10 minutes, wash quickly in successive alcohols, and mount in balsam or glycerin. Calvert (FIXED OILS). Characteristic color reactions are pro- duced on shaking fixed oils with one-fifth their bulk of nitric or sulphuric acid of varying strengths, and putting aside for five or ten minutes. A mixture of the strong acids (equal parts) may also be used, and when nitric acid is used alone, an excess of soda solution may or may not be used subsequently. TESTS AND REAGENTS. 41 Other variations of the test involve the use of syrupy phos- phoric acid, nitre-hydrochloric acid, followed by excess of soda solution; a mixture of equal volumes of water, nitric acid and sulphuric acid ; or i volume of soda solution may be added to 4 volumes of oil, prior to boiling. Camoin (SESAME OIL). Same as Baudoiri's test. Campani (COPPER). Copper gives a yellow to orange-red pre- cipitate on mixing a solution of glucose with lead-subacetate solution. Campani (GLUCOSE). Mixture of a concentrated lead-acetate solution with a dilute copper-acetate solution. Cane-sugar causes no change; glucose reduces the copper salt. Campani (MANGANESE). Exhaust ashes containing manganese with hot water and boil with mixture of nitric acid, 85 vol- umes, phosphoric acid, 15 volumes. Evaporate clear liquid to dryness, take up residue with hydrochloric acid, and again evaporate to dryness amethyst color develops. Campani (POTASSIUM SALTS). Bismuth-sodium-thiosulphate (obtained by dissolving bismuth subnitrate, i, in smallest possible quantity of hydrochloric acid, and adding sodium thiosulphate, i). In aqueous solution potassium salts give with reagent a yellow precipitate insoluble in alcohol. Candussio (PHENOLS). Solut. of potassium ferricyanide, i part in 100 parts 10- or 20-% ammonia, gives various color reac- tions with different phenols. Capezzuoli (SUGAR). Precipitate ferric hydroxide by excess of potassa. If sugar present, a dark, orange-yellow ring is devel- oped in 24 hours at surface of precipitate. Cappagnoli (GLUCOSE). According to Wilder, a blue color is produced on adding solut. copper hydroxide in potassa solu- tion. Capranika (BILIARY PIGMENTS). Add solut. bromine in chlo- roform to urine if biliary pigments present a green color develops, which, on shaking with hydrochloric acid, is taken up by the acid. Capranika (GUANINE). With solutions containing guanine, picric acid gives yellow, concentrated potassium chromate an orange red, and potassium ferricyanide a brown precipitate. Carcano (DIFFERENTIATING BOILED FROM UNBOILED MILK). 42 TESTS AND REAGENTS Add a few drops of fairly fresh oil turpentine to a few Cc. milk in porcelain saucer and heat slowly, then add alcoholic solut. resin guaiac unboiled milk is colored blue; boiled milk gives no color. Carey Lea (GELATIN). Acid solution of mercuric nitrate gives a red color. Carey Lea (HYDROCYANIC ACID AND CYANIDES). Ferrous- ammonio-sulphate, i; uranium nitrate, i; water, 240 or 250. Reagent gives a purple-red color or precipitate with hydro- cyanic acid or its salts. Add 2 drops of the suspected liquid, on a porcelain slab, to 2 drops of the test solution, so that the two liquids just touch. Carey Lea (THIOSULPHATES). A rose-red to scarlet color is produced on boiling with a few drops solution of ruthenium chloride in presence of ammonia. Carey Lea (IODINE). A bluish color is developed on adding starch paste, stirring well, then adding a drop dilute solut. of potassium bichromate and a few drops of hydrochloric acid. Carizzi (BLEACHING PROCESS). Cover small quantity of so- dium dioxide with io-% solut. tartaric or acetic acid, and cautiously overlay with 70-% alcohol. Saturate objects with alcohol, and suspend in supernatant alcoholic fluid. Avoid using mineral acids or much dioxide, or reaction may be very violent. Carlinfanti (MODIFIED BAUDOUIN'S TEST). After shaking oil with hydrochloric acid containing sugar, allow mixture to deposit if sesame oil present, the hydrochloric acid appears purplish-red; color is permanent on dilution with three parts water, whereas a similar coloration, when pure olive oil is. present, disappears. Carnot (ARSENIC). Precipitate as sulphide, and convert latter into arsenic acid by ammonia, silver nitrate and hydrogen peroxide and determine this as bismuth arsenate (very in- soluble in dil. nitric acid), which is simply dried and weighed. Carnoy (ACETIC ALCOHOL), i. Glacial acetic acid, i part;; absolute alcohol, 3 parts. 2. Glacial acetic acid, i part;, absolute alcohol, 6 parts; chloroform, 3 parts. The addition of chloroform is said to render the action of the mixture more rapid. TESTS AND REAGENTS. 4& Carnoy (HARDENING SOLUTION). Chromic-acid solution (2-%),. 45; osmic-acid solution (2-%), 16; glacial acetic acid, 3. Carnoy (SALT SOLUTION). Add a trace of osmic acid to a, 0.75-% aqueous solut. sodium chloride. Carnoy (TANNIN SOLUTION). Tannin, 0.5 Gm.; water, looGm. Carnoy (ToLU CEMENT). Tolu balsam, 2 parts; Canada bal- sam, i part; saturated solution shellac in chloroform, 2 parts; and enough chloroform to make cement of syrupy consistence. Caro (REAGENT). Solut. potass, persulphate in cone. H 2 SO 4 . Used as an oxidizer. Caro- Fischer (SULPHURETTED HYDROGEN). The reagent is para- amido-dimethylaniline sulphate. Add to fluid to be tested i~5oth of its weight strong hydrochloric acid and a few par- ticles of the sulphate, followed by a few drops dilute ferric- chloride solution if sulphuretted hydrogen present, methy- lene blue is formed, which is at once evident from its charac- teristic color. Carpene" (TANNIN IN WINE). Tannin is precipitated by a saturated solution zinc acetate in 5-% ammonia. Carter (FIXING SOLUTION). Formaldehyde, 10; dist. water, 10; acetic acid, i. Solut. kills and fixes tissues very quickly, and does not shrink cells. Leave tissues in solut. 6 to 12 hours, remove to 50-% alcohol for i hour, then leave 15 to 30 min- utes in 75-% alcohol, then for equal period in 90-% alcohol, then mount as usual. Any staining solut. may be used with this fixing solut. Carter (!NDICAN IN URINE). Overlay urine on nitric acid play of colors ensues, and a deep-blue to purple ppt. forms on adding sulphuric acid. Bile also gives play of colors. Casali (BILIARY PIGMENTS), i. On adding barium dioxide, lead dioxide, stannic chloride, or antimonous chloride, with either sulphuric or hydrochloric acid, to a biliary pigment, a play of colors through yellow, red, wine-red, violet, and bluish- violet takes place. 2. Various colors are produced on pre- cipitating urine containing biliary matter with solution lead acetate and ammonia, extracting with ether and hydrochloric- acid, evaporating ethereal layer, and adding oxidizing agents.. Casamajor (GLUCOSE). Methyl alcohol causes a cloudy appear- ance. 44 TESTS AND REAGENTS. Casoria (WATER IN ALCOHOL). Absolute alcohol does not affect color of dehydrated copper sulphate, but if water pres- ent the salt turns blue. Castle (BROMINE AND IODINE). Dichlorbenzene-sulphamide, in solid substance or solution in chloroform, is added to the solution to be tested. From metallic iodides and bromides the halogens are liberated as by free chlorine, and can be recognized by the color imparted to carbon disulphide or chloroform. Causse (POLLUTED WATER). Pure water restores the color to hexamethylene rosaniline decolorized by H 2 SO 4 , while pol- luted waters give no color with the reagent. Reagent is an -aqueous 1:1,000 solut. of "violet crystals" decolorized by H 2 S0 4 . Cavalli (ALKALINITY OF WATER). Add 2 or 3 drops of a i-% solut. toluylene-red to 50 Cc. water intense yellow if water alkaline; if alkalinity very slight, color is orange or pale- red. Sensitive i : i ,000,000 to alkali carbonate. Cazeneuve (COAL-TAR DYES IN WINES). The nitrate from natural wines when shaken with yellow mercuric oxide is colorless; if aniline dyes are present it is distinctly colored. Cazeneuve (METALS). Diphenyl carbazide in benzin solut. gives various color reactions with different metallic salts, in very dil. aqueous solut., e. g. copper gives a fine violet, passing into the benzin ; mercurous salts give a dark-blue and ferrous salts a pink, becoming brown with potass, ferrocyanide, even in dil. of 1:100,000. Color is destroyed by excess of acids. Gold and silver salts give rose tints with pptn. of metal; chromic acid ( i : i ,000 ,000 part of metal) gives a decided violet color stable with excess of acids, and not taken up by benzin, but taken up by amylic alcohol. Cazeneuve-Cotton (METHYL ALCOHOL). Distil several frac- tions of suspected spirit and add to each i Cc. of potassium- permanganate solution (0.5-%). If free from methyl alcohol, only the first two fractions immediately reduce the color. Cazeneuve-Defournel (NITRATES IN WATER). Glacial formic acid is used instead of sulphuric acid in applying the brucine test for nitrates. Chamberlain- Austen. See A usten-Chamberlain. TESTS AND REAGENTS. 45 Chancel (FUCHSINE). Wine colored with fuchsine retains its. color after heating 10 Cc. with 3 Cc. of lead-subacetate solu- tion (1:20) and filtering. Acidify red filtrate with acetic acid, take up the color with fusel oil and identify. Chapman (PHENOLS). Dissolve i Cc. of the phenol in 5 Cc. acetic anhydride, and add a small fragment ZnCl 2 , or cone. H 2 SO 4 . Some of the color-reactions are as follows: Eugenol with H 2 SO 4 , brown, changing to purple and finally wine red; with ZnCl 2 , pale-yellow, disappearing on standing. Iso- eugenol with H 2 SO 4 , rose-red becoming light-brown; with ZnCl 2 , rose-red. Saffrol with H 2 SO 4 emerald-green, chang- ing to brownish-green and finally brownish; with ZnCl 2 , pale- blue, finally light-brown. Iso-saffrol with H 2 SO 4 pale-pink, becoming reddish; with ZnCl 2 , pink, becoming brownish-red and finally brown. Estragol with H 2 SO 4 , purple, then indigo-blue, and finally bluish-purple; with ZnCl 2 , bluish- violet to indigo-blue, and finally brownish. Anethol with H 2 SO 4 , at first no color, then pale-yellow after a time; with ZnCl 2 , pale-yellow becoming darker, and finally brick- red. Chapman-Smith (TARTARIC AND CITRIC ACIDS). Boil with a strongly alkaline solution potassium permanganate tartaric acid reduces it at once ; with citric acid the green color remains. Chatard (NITROUS ACID). A distinct odor of carbolic acid is apparent on evaporating a solution of nitrous acid nearly to. dryness and rubbing with a few drops aniline-sulphate so- lution. Cha tin- Gaul tier de Claubry (IODINE). A blue to violet color is produced on adding starch together with a mixture of nitric acid, i volume, and sulphuric acid, 6 volumes. Chautard (ACETONE IN URINE), i. Dissolve i part fuchsine in 1 50. parts warm water, and pass in current of sulphurous- acid gas till decolorized. This solution added to an equal vol- ume of urine is reddened in i to 2 minutes if acetone is present. 2. Distil 200 Cc. of urine and test first 15 Cc. with decolorized magenta solution, made by mixing 30 Cc. magenta solution (i in 1,000), 20 Cc. saturated sodium-bisulphite solu- tion, 3 Cc. strong sulphuric acid, and 200 Cc. water. See also Gay on' s test. 46 TESTS AND REAGENTS. Chenzinsky (METHYLENE BLUE AND EOSINE). Saturated aqueous solution methylene blue, 40 parts; 0.5-% solution eosine in 70-% alcohol, 20 parts; distilled water or glycerin, 40 parts. Chevreuil (TEST-PAPER). Hematoxylin Paper. Paper gives with alkalies a blue color, and with acids a red. Chevreul (AMMONIA). Red color of hematoxylin paper is changed to violet or blue by ammonia. Chiappe (MINERAL ACIDS IN VINEGAR). Color of methyl violet is changed to ultramarine-blue on adding to vinegar containing mineral acids. Chlopin (OZONE). Dissolve Ursol D. or T., in absolute alcohol, and impregnate strips of ordinary filtering paper with the brown solution, which must be freshly prepared each time before use. On moistening the test-paper with water and exposing it in an atmosphere containing ozone, it immediately acquires a blue color, which, according to the quantity of ozone present in the air, may change to a violet or dark-blue. The new test- paper is not affected by H 2 O 2 . H 2 S0 3 , Cl and Br, color the Ursol paper at first bluish-green, but the color, however, soon changes to yellow. CO 2 is said to be entirely without action on the new test-paper. Christen (ALBUMIN). Tannin produces a turbidity or precipi- tate with solution of albumin. Ciamician-Magnanini (SKATOL). Heat skatol with sulphuric acid a bright purple red color develops. Clark (CREOSOTE; PHENOL). Boil with excess of nitric acid till red fumes no longer evolved carbolic acid forms yellow crystals; creosote does not. Clark (SOAP SOLUTION). Dissolve 10 Gm. Castile Soap in 35-% alcohol, and standardize against a solut. made by dis- solving i Gm. CaCO 3 in smallest excess of HC1, neutralizing with NH 3 and adding H 2 O to i ,000 Cc. Clarus (SOLANINE). Chromic acid solution gives a sky-blue color with solanine. Claus (UREA). Nitrous acid decomposes urea in solut. into carbon dioxide and nitrogen. Course of reaction depends on quantity of nitrous acid and other circumstances. Claus (WATER). Moisten anthraquinone and sodium amalgam TESTS AND REAGENTS. 47 with alcohol if latter contains water a red color develops. Absolute alcohol gives a green color. Clowes (INFLAMMABLE GAS). Test serves for detecting and estimating inflammable gases in air, present in least explosive proportion. Burn a hydrogen flame 10 Mm. in height in air to be examined the appearance of the pale flame or "cap" surmounting and surrounding the hydrogen flame, and ob- served against a black background in a darkened space, serves as an indication of gas or vapor, and the height of the cap may be directly translated into percentages of gas present by tables published by author in his ' ' Detection and Measure- ment of Inflammable Gas and Vapor in Air." Codina-Laenglin (OLIVE OIL). Heat i Gm. dilute nitric acid (nitric acid, sp. gr. 1.33, 3 parts; water, i part) with 3 Gm. olive oil on water-bath characteristic color-reactions take place. Cohen (ALBUMIN). Solution bismuth-potassium iodide pre- cipitates albumin and alkaloids from acid solutions. See Dragendorff's test. Cohn (CULTURE SOLUTIONS), i. Water, 200 Cc.; ammonium tartrate, 2 Gm.; potassium phosphate, 2 Gm. ; magnesium sulphate, o.i Gm. ; tricalcic phosphate, o.i Gm. 2. (CORN'S NORMAL SOLUTION.) Water, 200 Cc.; acid potassium phos- phate, i Gm. ; magnesium sulphate, i Gm. ; ammonium tartrate, 2 Gm.; calcium chloride, o.i Gm. Cohnheim (GOLD METHOD). Place pieces of tissues in 0.5-% gold-chloride solut. until quite yellow, then expose to light in water acidulated with acetic acid until gold thoroughly re- duced. Mount specimens in acidulated glycerin. Colasanti (SULPHOCYANIC ACID). Warm a dilute solut. of substance with solut. of gold chloride (1:1,000-10,000) in potassium hydrate or sat. solut. sodium bicarbonate violet color develops, and gold deposits on cooling. Cole (CARMINE METHOD). Wash sections in water to remove alcohol, then stain with Grenadier's borax-carmine 3 to 5 minutes, and wash in methylated spirit. Afterwards immerse in mixture methylated spirit, 5 parts, and hydrochloric acid, i part, for 5 to 10 minutes. Again wash well in spirit to remove all traces of acid, then dehydrate in stronger spirit for 43 TESTS AND REAGENTS. 10 to 15 minutes, clear in clove oil for 5 minutes, wash in tur- pentine, and mount in benzene-balsam. Cole (FREEZING PROCESS). Dissolve picked acacia, 4 oz., in distilled water, 6 fl. oz., and to each 5 parts of resulting mu- cilage add 3 parts syrup (sugar, i pound, in distilled water, i pint). To each ounce of medium add 5 grains pure carbolic acid, and soak tissues in it prior to freezing. For tissues liable to come in pieces mix 4 parts syrup with 5 of mucilage. Cole (HEMATOXYLIN METHOD), a. Hematoxylin, 30 grains; absolute alcohol, 3^ fl. oz.; b. ammonia alum, 30 grains; water, 3^ fl. oz. Mix a and 6, then add glycerin, 3^ fl. oz., and glacial acetic acid, 3 fl. dr. Leave mixture exposed to light for at least a month, then filter and keep in a stoppered bottle. Wash sections in distilled water to remove alcohol, or if the material has been hardened with chromic acid, treat with i-% aqueous solution of sodium bicarbonate and then wash well in water. Next add 10 to 20 drops of the hematoxy- lin solution to a watch-glassful distilled water and immerse sections for 10 to 30 minutes. Again wash in distilled water r then in ordinary tap water, dehydrate with methylated spirit, clear in clov.e oil, and mount in benzene-balsam. If sections over-stained, remove excess of color before dehydration by soaking for a few minutes in a 0.5-% solution glacial acetic acid in distilled water, then wash again in tap water and pro- ceed as above. Cole (HEMATOXYLIN AND EOSINE METHOD). Stain sections with hematoxylin as above, but before clearing immerse in alcoholic solution eosine (i grain to i fl. oz.) for five minutes, wash well in methylated spirit, clear in clove oil, and mount in benzene-balsam. Cole (PICROCARMINE METHOD). Dissolve i Gm. carmine in 10 Cc. distilled water and 3 Cc. of strong ammonia, then add solution to 200 Cc. of a saturated aqueous solution picric acid. Leave mixture exposed to the air until it has evaporated to one-third its bulk, then filter and keep in a stoppered bottle. Stain sections for 0.5 to i hour, place on slides without wash- ing, and after draining off excess of stain, mount in Farrant's medium. Cole (SLOW OR EXPOSURE METHOD OF MOUNTING). Dissolve TESTS AND REAGENTS. 49 dried Canada balsam, 3 oz., in benzene, 3 fl. oz., and filter. Apply a clean cover-glass to a slide that has been moistened by breathing on it, and place a few drops of balsam solution on cover-glass. Then remove a section from turpentine, and put it into the balsam. Put aside for 12 hours to allow benzene to evaporate, and having warmed a slide and added a drop fresh balsam solution to that on cover-glass, bring the fluid balsam in contact with the warmed side. Press cover down carefully to avoid inclusion of air bubbles, and when excess of balsam is squeezed out, put slide aside to cool, after which it may be cleaned with a camel's-hair brush or soft rag moist- ened with methylated spirit. Conrady (CANE SUGAR IN MILK SUGAR). Dissolve i Gm. of milk sugar in 10 Cc. water; then add o.i Gm. resorcin and i Cc. hydrochloric acid, and boil mixture for five minutes if cane sugar present a reddish color develops. Conroy (COTTONSEED OIL IN LARD). Silver nitrate, 5; nitric acid (sp. gr. 1.42), i; alcohol, 100. Melt 10 Gm. lard in test- tube, add 2 Gm. test-solution, and immerse tube in boiling water for 5 minutes pure lard remains white, but cottonseed oil present (even i%) causes brownish color. Conroy (OLIVE OIL). Heat 9 volumes of oil with i volume nitric acid (sp. gr. 1.42), and note color and consistence of the mixture. Contejean (FREE HYDROCHLORIC ACID IN GASTRIC JUICE). Heat a drop of gastric juice with freshly precipitated cobaltous hydroxide in a watch-glass if hydrochloric acid present, co- baltous chloride forms, and colors solution blue on evaporation. Corne (!ODATES). Starch and water, in which phosphorus has been kept, give with iodides containing iodates, a blue color. Cotton (BRUCINE). A violet to green color develops on adding excess of sodium-sulphydrate solution to a warm solution of brucine in nitric acid. Cotton (PHENOL). See Lex's test. Cotton-Cazeneuve. See Cazeneuve-Cotton. Couerbe (NARCOTINE). A blood-red color develops on heating with sulphuric acid. Cox (MERCURIC IMPREGNATION MIXTURE). Five-per cent, potassium-bichromate solution, 20 parts; 5-% mercuric- 50 TESTS AND REAGENTS. chloride solution, 20 parts; 5-% potassium-chromate solution, 1 6 parts; water, 30 to 40 parts. Crace-Calvert (FATTY OILS). Treat oils with sulphuric and nitric acids of given concentration, with phosphoric acid, or with nitro-hydrochloric acid, and note color reactions, as well as changes in color and consistency caused by boiling oils with soda lye, either with or without addition of hydrochloric acid. For detailed information, see Benedikt, "Analyse der Fette" edit. II, p. 307. Cramp ton-Simons (CARAMEL IN LIQUOR AND VINEGAR). Add 25 Gm. Fuller's earth to. 50 Cc. of liquid in beaker, let stand 30 minutes, and filter. Percentage of color absorption is deter- mined by Lovibond tintometer before and after treatment; or compare with sample of liquid colored. Cresti (COPPER). Place a zinc-platinum element, formed of two wires, in liquid suspected to contain copper; on removing the platinum wire, rinse with water and expose for a moment to action of hydrobromic acid and bromine vapors, produced by heating potassium bromide with sulphuric acid the deposit of copper becomes violet. Creuse (SALICIN IN QUININE). Potassium bichromate and dilute sulphuric acid give no change with quinine. If salicin present, odor of salicylic aldehyde develops. Cripps-Dymond (ALOES), i. Triturate 0.05 Gm. aloes, or residue left upon evaporation, with 16 drops cone, sulphuric acid and 4 drops nitric acid (sp. gr. 1.4), and add 30 Gm. water an orange to carmine color develops, which is darkened to deep wine-red by ammonia. (Rhubarb, senna and frangula interfere with the reaction.) 2. All aloins are precipitated by ferric chloride or lead acetate. Barbaloin and nataloin are colored carmine-red by cold nitric acid ; socaloin and curag- aloin are colored red by fuming nitric acid. Barbaloin, dis- solved in a drop of concentrated sulphuric acid, is colored red upon the addition of nitric acid. Nataloin is colored blue by similar treatment. Crismer (ALDEHYDES). Nessler's reagent, or a solut. potassio- mercuric iodide with baryta water, affords yellow to brown- black precipitates insol. in potassium cyanide. Crismer (INDICATOR). The indicator for alkalimetry, known TESTS AND REAGENTS. 51 as "resazurin," is obtained by adding 45 drops nitric acid, sp. gr. 1.25, saturated with nitrous acid, to a solution of resorcin, 4 Gm., in anhydrous ether, 200 Cc. After standing for two days the crystals which have formed are separated and washed with ether until washings colored blue with ammonia. It gives a red color with acids and blue with alkalies and alkali carbonates. Crismer (SAFRANINE TEST FOR GLUCOSE). Heat to 6o-65 C., 5 Cc. of a i : i, ooo aqueous solution safranine with i Cc. urine and 2 Cc. of a io-% soda solution; liquid is decolorized if glucose present. Allen takes equal measures (2 Cc.) of safranine solution, urine, and normal soda or potash solution, and heats mixture till it boils freely. If urine contains more than 0.1% sugar, liquid will be decolorized, but otherwise the red color remains intact or is only partially discharged. Uric acid and creatinine do not affect safranine. Crismer (TARTARIC ACID). Trace of tartaric acid added to a weak solution ammonium molybdate, followed by one or two drops hydrogen dioxide, or a trace of sodium peroxide, and the mixture warmed to 60 C., gives at first a green color which changes to blue. Crismer (TURPENTINE IN VOLATILE OILS). Dissolve 20 Gm. potassium bitartrate in i liter water, and neutralize with manganous carbonate (about 6 Gm.), mix 3 Cc. of this solu- tion, 5 Cc. of suspected oil, and 5 drops ammonia water, shake well, heat on water-bath, and pass current of air through mix- ture for 30 seconds. Oils of lemon and bergamot become dark brown; oil turpentine turns intense brownish black; most volatile oils, if pure, acquire only faint yellowish tinge. Crolas-Ducker (URANIUM SALTS). Macerate a mixture of cochineal, 10, and alum, 10, with 6o-% alcohol, for 48 hours, then filter. Solution gives a green color with uranium salts. Malot suggests that it may be used as an indicator for the titration of phosphoric acid. Crook (BUTTER). Pure butter yields a clear liquid on melting 10 grains in a test-tube, adding 30 minims carbolic acid (Cal- vert's No. 2, diluted with one-eighth its weight water), shak- ing, warming till clear, and allowing to stand. Most other fats form two layers. 52 TESTS AND REAGENTS. Crookshank (STAINING FLAGELLA). Stain cover-glass prepa- rations with a drop of concentrated alcoholic solution of gen- tian violet, then rinse in water, allow to dry, and mount in balsam. Cross-Bevans (CELLULOSE SOLVENT). Solution zinc chloride, i part, in concentrated hydrochloric acid, 2 parts. Crouzel (SANTONIN IN URINE). On adding cone. Ca(OH) 2 to urine containing santonin eliminated by the kidneys, a char- acteristic carmine-red color develops. The color is best de- veloped by nascent Ca(OH) 2 , e. g., on adding some calcium carbide to the urine. The sensitiveness is such that o.i Gm. santonin taken internally will suffice to afford a color reac- tion with all the urine voided during the next 60 hours. The color lasts for about 30 minutes. Crouzel-Dupin (ANIMAL AND VEGETABLE FATS IN PETROLEUM). Add 5 drops satur. solut. potassium permanganate to 5 Gm. of petrolatum and triturate; if petrolatum pure, rose-red color persists; if not, permanganate is reduced and color becomes brown, depth depending on extent of admixture. Csokor's [Czoker's] (ALUM COCHINEAL). Dissolve i Gm. of ammonia alum in 100 Cc. distilled water, add i Gm. powdered cochineal and boil. After evaporating to half the original bulk, filter and add 0.5 Cc. of carbolic acid. Csokor's [Czoker's] (TURPENTINE CEMENT FOR CLOSING GLY- CERIN MOUNTS). Break common resinous turpentine of commerce into small pieces, melt on a water-bath, and allow to cool. A brittle, dark-brown mass results. See also Parker's turpentine cement. Cuccati (CARMINE SOLUTION). Dissolve 20 Gm. Na 2 C0 3 cryst. in 100 Cc. warm water, add 50 Gm. carmine, boil, remove from heat, and add 30 Gm. absolute alcohol. After several days filter, and slowly add 300 Gm. water, 8 Gm. 20-% solut. acetic acid, and 2 Gm. chloral hydrate. Requires 15 minutes for staining. Cunisset (BILIARY MATTER). A yellow color is imparted to chloroform shaken with urine containing biliary pigments. Curtman (POTASSIUM SALTS). A yellow precipitate forms on adding to a solution of a potassium salt a solution of i part TESTS AND REAGENTS. 53 cobalt nitrate in 10 parts saturated sodium-nitrate solution acidified with acetic acid. Czaplewski (CARBOL-GLYCERIN-FUCHSINE). i Gm. fuchsine, 5 Cc. liquefied carbolic acid, 50 Cc. glycerin, and 100 Cc. dist. water. Dilute 4 to 10 times for use as a stain. Czoker. See Csokor. Czumpelitz (ALKALOIDS). Characteristic color reactions de- velop on treating alkaloids with a solution of zinc chloride, i Gm., in 60 Cc. of a mixture containing equal parts of hydro- chloric acid and water. Dahlmann (PAPER). A very dilute solution of gold and sodium chloride produces a reddish-brown color with bleached and unbleached sulphite cellulose, sulphate cellulose, and soda cellulose, and a yellow color with wood-fibre; bleached straw paper shows no change of color. Danielewsky (AROMATIC SUBSTANCES IN BLOOD, ETC.). An azo-reagent (diazo-sulphanilic acid?) is added, the solution slightly acidified with hydrochloric acid, and then made alka- line presence of aromatic compounds is indicated by an orange-red color. Danziger (COBALT). The following test, properly carried out, will detect cobalt in a i : 500,000 aqueous solution, provided the solution is colorless, or but slightly colored: To about 5 Cc. of the solution, acidulated with HC1, add solid ammo- nium thioacetate together with a few drops of stannous-chlo- ride solution, and an equal volume of amyl alcohol, or a mix- ture of acetone and ether, or alcohol and ether: shake the whole well and allow to separate. If any cobalt is present, the upper layer will be colored blue, the intensity of the color varying with the amount of cobalt present. The SnCl 2 is added to reduce any iron present, as ferric iron gives a deep red color, as with ammonium thiocyanate. Amyl alcohol diminishes the dissociation, and extracts the color produced by the un dissociated cobalt salt. This consists of a double cobalt-ammonium thioacetate, containing two molecules of ammonium thioacetate to one molecule of cobalt thioacetate. Barton (GOLD). Reduce ore supposed to contain gold to fine powder and shake well in a test-tube with aqueous solution of iodine (iodine, i; potassium iodide, 1.5; water, 36). Dip 54 TESTS AND REAGENTS. a strip of filtering paper into the solution, dry and heat on platinum foil to redness. After cooling, ashes will be purple if gold present. Da Silva (ESERINE). Dissolve fragment of alkaloid or a salt in i or 2 drops fuming nitric acid, and heat on water-bath in capsule orange color develops. On evaporating to dryness while stirring residue becomes green. A drop of nitric acid added to residue turns it blue in spots, and forms finally a reddish- violet solution which changes to a fluorescent green- ish-yellow on dilution, and blood-red by transmitted light. David (ALCOHOL-ACETIC ACID FOR EXAMINATION OF FATTY ACIDS). 300 Cc. of 95-per cent, alcohol and 220 Cc. of a mix- ture of equal volumes of glacial acetic acid and water. This solution dissolves only the liquid fatty acids from a mixture of fatty acids, and leaves the solid fatty acids undissolved. Davy (ALCOHOL). Dissolve molybdic acid, i, in strong sul- phuric acid, 10. The solution gives a blue color on warming with any fluid containing alcohol. Detects i of alcohol in i ,000 of water. Essential oils should be shaken with water and separated before applying this test; urine must be dis- tilled. Davy (ARSENIC). The diluted sulphuric acid in Marsh's test is replaced by an amalgam of mercury and sodium. Davy (MANGANESE), i. A green color is produced on heating manganese to redness on silver foil with a few drops of potassa solution. 2. A white precipitate is formed on heating man- ganese to redness on platinum foil with sulphur, dissolving the residue in water and adding iron ferrocyanide. Davy (PHENOL). Dissolve molybdic acid, i, in strong sulphuric acid, 10, and add 3 or 4 drops to i or 2 drops of the suspected liquid. If phenol present a dark olive-green to blue and violet color develops. Davy (STRYCHNINE). A deep violet color is produced on treat- ing strychnine with sulphuric acid and adding powdered potassium ferricyanide. Davy-Leconte (UREA). On treating urea with a hypochlorite in alkaline solut., urea is decomposed into C0 2 and N. The former is absorbed by the alkali, and the volume of the latter then estimated. TESTS AND REAGENTS. 55 Day (Pus). The formation of a blue color upon the addition of i or 2 drops of an oxidized tincture of guaiac (old, or shaken with air) to urine indicates the presence of pus. Deacon (AMYGDALIN). On treating amygdalin with a few drops cone. H 2 SO 4 a bright carmine color develops, discharged on pouring into water. Deane (GLYCERIN JELLY). Soak gelatin, 30 Gm., in water, then melt and add glycerin, 120 Gm. Deane (MEDIUM). Soak gelatin, i oz., in water, 4 fl. oz., until soft, then add honey, 5 fl. oz., heated to boiling-point. Boil mixture, then allow to cool somewhat, but before it is set add alcohol, 4 fl. dr., and creosote, 5 or 6 drops. Finally, filter through fine flannel. Debrunner (NITROBENZENE). Nitrobenzene in alcoholic bev- erages can be detected by taking up with ether, separating, and adding a few drops dilute acetic acid, a little very fine iron filings, and sufficient water. When the oil drops have disap- peared, decant, treat with soda, take up with ether, evaporate, and add a few drops of hydrochloric acid, with a little potas- sium chlorate. A blue to green color indicates the presence of nitrobenzene. Debrunner (WATER IN ALCOHOL). A purple color on adding potassium permanganate to alcohol indicates the presence of water (the salt is insoluble in absolute alcohol). Dechan (INDICATOR). Gallein (alizarin violet). Gives a bright- red color with alkalies, and a pale-brown with acids. Deen, Van- (BLOOD). A blue color develops on adding a few drops of freshly prepared tincture guaiac and ozonized tur- pentine oil to a very dilute (almost colorless) liquid contain- ing blood. Defacqz (PHENOLS AND ALKALOIDS). Heat i part tungstic acid with 4 or 5 drops potassium bisulphate and few drops sulphuric acid, then add sufficient sulphuric acid to prevent solidification on cooling. Add i drop of reagent to i drop of solution (or few solid particles) to be tested, and triturate a few minutes with glass rod. Phenol very intense red; para-cresol intense red-brown; thymol vermillion; hydroqui- none very intense amethyst- violet ; resorcin red-brown; pyrocatechin black- violet. Sometimes black; pyrogallol 56 TESTS AND REAGENTS. red-black; alpha-naphtol violet-blue; beta-naphtol violet- blue; salicylic acid very intense Saturn red; meta-oxyben- zoic acid feeble Saturn red; para-oxybenzoic acid nothing; quinine and cinchonineiamt yellow; morphine amethyst- violet, then brown; codeine rose, turning violet; conicine intense rose; solanine gamboge; veratrine intense sienna, then red-brown; aconitine yellowish-brown; narceine yel- lowish-green, then moss-green; and picrotoxin very intense orange-red. In general these colors are destroyed by water. Strychnine, brucine, nicotine, atropine, cantharidin, caffeine, santonin, pilocarpine, ergotinine, and hyoscyamine give no color. Degener (INDICATOR). Phenacetolin, a brown substance ob- tained by heating together for several hours one equivalent each of phenol, sulphuric acid, and glacial acetic acid, is turned red by caustic alkalies; but yellow with acids. Deiss (COTTONSEED OIL). See Labiche's test. Delafield (HEMATOXYLIN). Hematoxylin, 4 Gm., and absolute alcohol, 25 Cc.; add the solution to 400 Cc. of a saturated aqueous solution of ammonia alum. Expose mixture to light and air for 3 to 4 days, then filter and add glycerin, 100 Cc., and methylic alcohol, 100 Cc. Again expose the solution to light until it becomes dark-colored, then filter and preserve in a stoppered bottle. See also Grenadier's test. Delffs (ALKALOIDS). Potassium platino-cyanide forms salts with alkaloids. See Mayer's test. Delffs (CAFFEINE). A crystalline precipitate falls on adding solut. mercuric oxide in potassium iodide to a solut. of caf- feine. Other alkaloids yield amorphous precipitates. Deniges (CHLORATES). Resorcin, i Gm. ; water, 100 Cc.; sul- phuric acid, 10 drops. Mix 2 drops of suspected liquid with 2 Cc. sulphuric acid, cool, and add 5 drops of reagent green color develops if not more than 2% chlorate present (Ni- trates give yellowish color turning to purplish-red; nitrites a blue; hence insure their absence). Deniges (CITRIC ACID). To 5 Cc. of citrate solution add i Cc. of mercuric-sulphate solution (mercuric oxide, 5 Gm.; cone, sulphuric acid 20 Cc.; water 100 Cc.). Boil, and add while warm 5 or 6 drops permanganate solut. decolonization TESTS AND REAGENTS. 57 rapidly ensues, and characteristic white ppt. forms. Test not affected by other organic acids. Deniges (GLYCERIN), i. Nessler's test. 2. Hot mixture of equal vol. 2-% silver-nitrate solut., ammonia, and soda lye. Exhaust substance, mix extract with 4 parts potassium bisul- phate, and heat. A rod moistened with Nessler's solut. or the silver solution will show slightest trace of acrolein, the tip becoming brown to black. Deniges (HYDROCYANIC ACID). Ammonia water, 2 Cc.; io-% potassium-iodide solution, i drop; water, 20 Cc.; silver- nitrate solut. (2-%), i drop. Place a few Cc. of liquid to be examined in test-tube with zinc and 15 to 20 drops sulphuric acid, and hold glass rod moistened with potassa solution in space over liquid. Now dip rod in reagent if any hydro- cyanic acid present (as potassium salt on rod) the opalescent reagent becomes clear. Deniges (HYDROGEN DIOXIDE). Mixture of i Cc. of a io-% aqueous ammonium-molybdate solut. and i Cc. cone, sul- phuric acid. Hydrogen dioxide gives an intensely yellow color with this reagent. Deniges (!ODOFORM). Evaporate ethereal extract containing iodoform to dryness and add 3 or 4 drops of a liquid contain- ing iodoform with 4 or 5 drops dimethylamine a yellow color develops proportionate to iodoform present. Heat mixture carefully to boiling, cool, and add alcohol the liquid is red by transmitted light and violet by reflected light if much iodo- form present; if only little iodoform, liquid is violet. Deniges (METALS). Alloxan solut. (extemporaneously pre- pared) gives color reactions with various metals. Reagent is prepared by heating 2 Gm. uric acid with 2 Cc. HNO 3 (40 Be\), and when the reaction is over adding 2 Cc. water, heating until solution is perfected, and then making up to 100 Cc. A few Ccs. of reagent with a little solut. of a ferrous salt and a drop or two of KOH solut. gives a fine blue changing to light yellow (sensitive i : 100,000). On boiling reagent with zinc a yellow to orange color develops, depending on quantity of zinc present. With magnesium a carmine color develops. -Cadmium gives a grenadine tint. Iron gives a brownish- 58 TESTS AND REAGENTS. '_ i yellow. Nickel and cobalt give an orange. Manganese affords a carmine-red. For details see MERCK'S REPORT xi, p. 56. Deniges (NITRATES AND NITRITES). Add 0.5 Cc. of a i : 20 antipyrine solut. and 1.5 Cc. of cone, sulphuric acid to i Cc. of solut. containing nitrate or nitric acid a carmine-red color develops. If 3 Cc. acid used, color is at first orange to yellow, but on diluting with water, carmine-red. If nitrous acid present, greenish-blue develops (nitroso-antipyrine) changed by sulphuric acid to yellow or orange, and on diluting with water to light-yellow. If both nitrates and nitrites present, add 3 or 4 drops sulphuric acid to mixture, heat, then cool, and add 0.5 Cc. i : 20 antipyrine solut. a greenish-blue or greenish-yellow indicates nitrites. Now add 3 Cc. more acid an orange color changed to carmine-red on diluting with water indicates nitrates. Chlorates interfere with reaction; if these present, add 4 drops acid and 2 drops sodium-bisul- phite solut. to i Cc. of solut. to be tested and proceed as above. Deniges (NITRITES), i. (a) Phenol, i Gm.; sulphuric acid, 4 Cc. ; water, 100 Cc. (b) Mercuric acetate 5 Gm. (or oxide 3.5 Gm.); glacial acetic acid, 20 Cc. ; water, 100 Cc. Shake for a while, add 0.5 Cc. sulphuric acid, and filter. To use, mix 2 Cc. each of a and b, boil, and add i or 2 drops of solution to be examined if 0.5 Gm. nitrite per liter present, an imme- diate red develops; if solution so dilute that color develops slowly, add i to 10 Cc. to reagent and boil. Reagent unaf- fected by light, air, nitrates, chlorates, hypochlorites, hypo- bromites, chlorine, bromine, etc. 2. Aniline, 2 Cc. ; glacial acetic acid, 40 Cc. ; water to make 100 Cc. Boil 5 Cc. of re- agent with suspected liquid (o.i to 10 Cc. according to concen- tration) pale-yellow to dark-orange color develops, changed to red by a few drops HC1 or H 2 SO 4 , but restored by sodium hydrate or acetate. Reagent not affected by chlorates or nitrates, but is by hypochlorites, hypobromites, chlorine and bromine. 3. Resorcin, i Gm.; water, 100 Cc.; sulphuric acid, 10 drops. Mix 4 drops of suspected liquid, 2 Cc. sulphuric acid, and 5 drops reagent a very intense carmine or violet color develops. Chlorates give a green color with the last reagent. TESTS AND REAGENTS. S9 Deniges (TYROSIN). Cone, solut. of aldehyde in sulphuric acid gives with tyrosin a handsome carmine-red condensation pro- duct exhibiting absorption bands covering all the green and almost all the yellow of the spectrum. Deniges (URIC ACID IN URINARY CALCULI). Triturate few pieces of calculi with 5 or 6 Cc. water and 2 drops soda-lye, boil, dilute with equal volume water, and filter. To filtrate add J its volume of acid mercury-sulphate solut. (mercuric chloride 5 Gm.; sulphuric acid 20 Cc., water 100 Cc.). If uric acid present, a white flocculent ppt. forms. Deniges (TIN). Ammonium molybdate, i Gm. ; water, 10 Cc., sulphuric acid, 10 Cc. Reagent gives a blue color with tin in solution. Deniges (URIC ACID). Uric acid is converted into alloxan by careful treatment with nitric acid. After evaporating off excess of acid a few drops of sulphuric acid and of benzene containing thiophene are added, when a blue color will be developed by the alloxan. Desbassins (NITRIC ACID). See Richmond's test. De Souza (HARDENING METHOD). Pyridine is used to harden,, dehydrate and clear tissues at the same time. They may be stained after hardening by aniline dyes dissolved in the pyri- dine, or passed through water and stained by the Usual methods. Deubner (BILIARY PIGMENTS). See Gmelin's test. Deventer (NITRITES). Ferrocyanide of potassium is oxidized: to ferricyanide by nitrites (nitrous acid.) Deville (PHENOL). Ferric chloride gives with carbolic acid a- bluish- violet color. Devoto (PEPTONE). All other albuminoids are precipitated by addition of crystalline ammonium sulphate; peptone is de- tected in the filtrate by the biuret reaction. According to Bogomolow and Wassilieff, peptone may also be detected in this filtrate by Roch's reagent (salicyl-sulphonic acid) or by means of resorcin and trichloracetic acid. De Vrij (CHROMATE TEST FOR QUININE). Dissolve i Gm. quinine in 45 Cc. boiling water, add 2.5 Gm. neutral potassium chromate, cool to 15 C., and after an hour filter off the crystallized quinine chromate. To 10 Cc. of filtrate add one ; 60 TESTS AND REAGENTS. drop of soda lye, or until solution reddens phenolphtalein paper. If quinine free from other cinchona alkaloids, solution remains clear, even upon heating; if otherwise, a turbidity ensues. De Vrij (HERAPATHITE REACTION FOR QUININE). Dissolve 8 parts quinoidine sulphate in 8 parts 5-% aqueous sulphuric acid, and carefully precipitate with an iodine solution (i part iodine, 2 parts potassium iodide, and 100 parts water). Dis- solve precipitate, which, after washing and drying, becomes resinous, in six times its weight of 92- to 94-% alcohol, filter, and evaporate and dissolve residue in five times its weight alcohol. This solution produces with quinine-sulphate solu- tion a precipitate of quinine iodosulphate. Diesel (OLIVE OIL). Color reactions occur on adding nitric acid to olive oil. Dieterich (ALOES). Evaporate solution of substance to dryness with a few drops of nitric acid, sp. gr. 1.4, and take up residue with one drop alcohol; on adding alcoholic solution of potas- sium cyanide, a pink color is given by aloes. Dieterich (DISTINCTION OF CATECHUS). If Gambier catechu, 3 Gm., is treated with normal potassa solution, 25 Cc., and water 100 Cc., and the solution shaken out with benzene, 50 Cc., the benzene layer is colored intense green. Pegu catechu does not give this reaction. Dietrich (URIC ACID). Sodium hypochlorite solution contain- ing bromine gives with solution of uric acid an unstable rose- red color. Di Vetere (CASTOR OIL IN OLIVE OIL). Shake a sample of the oil with concentrated hydrochloric acid three layers form if castor oil present. Dobbin (CAUSTIC ALKALI). Reagent is prepared by adding mercuric-chloride solut. to a solut. of 5 Gm. potassium iodide, until permanent precipitate forms. Remove this by filtration, add i Gm. ammonium chloride to filtrate, and then sufficient dilute soda lye until a permanent precipitate is again obtained. The filtrate is then diluted to i liter. Reagent is applicable for detection of traces of free alkalies in potassium and sodium carbonates. Caustic alkalies, TESTS AND REAGENTS. 6r including ammonia, produce a yellow to reddish-brown color or precipitate, according to the quantity present. Dodge-Olcott (COPAIBA BALSAM). Add 4 drops of oleoresin to 4 fl. dr. glacial acetic acid, then add 6 drops strong nitric acid the mixture remains colorless if oleoresin is pure. Dogiel (METHYLENE-BLUE IMPREGNATION METHOD). Place pieces of tissue in a 4-% solut. methylene blue in 0.75-% salt solution, let remain for a few minutes, then place for half an hour or more in a saturated aqueous solution of ammonium picrate. Finally, wash in fresh ammonium-picrate solution and examine in dilute glycerin. Dogiel (METHYLENE-BLUE STAINING METHOD). Place objects (pieces of retina, etc.) to be stained in a few drops aqueous or vitreous humor, to which add 2 or 3 drops of 0.06-% solution methylene blue in physiological-salt solution, and expose to air. Stain takes effect in 5 or 10 minutes, and attains its maximum in 15 to 20 minutes, though thicker specimens may require several hours. Reaction may be hastened by placing preparations in a stove kept at 30 to 35 C. Donath (CHROMIC ACID). In presence of a bichromate, free chromic acid may be detected by violet color imparted to carbon disulphide, added after shaking solution with potas- sium-iodide solution. Donath (FREE ACID). A violet color is imparted to carbon disulphide on adding a few Cc. to liquid containing free acid, after the addition of a little potassium iodide and some bichromate. Donath (NITROGEN). Heat 0.05 Gm. of substance with i Gm. potassium permanganate, and 20 Cc. of pure, saturated potassa solution to boiling, and if necessary add more perman- ganate until coloration permanent. On cooling, dilute mix- ture with water, decompose excess of permanganate by the addition of alcohol, remove precipitate by filtration, and test, filtrate for nitric acid by usual methods. Donath (POTASSIUM BICHROMATE). A brown cloudiness or precipitate develops on bringing a solut. of sodium thiosul- phate to boiling-point and adding an equal volume of pre- viously heated liquid containing potassium bichromate, if chromate present. 62 TESTS AND REAGENTS. Donath (POTASSIUM CHROMATE). Heavy blackish-brown pre- cipitate forms on boiling a liquid containing potassium chro- mate in the presence of bichromate and adding a drop of manganese-sulphate solution. Donath (RESIN IN WAX), i. Boil 0.8 Gm. of sample, and for comparison the same quantity of pure wax, with 10 Cc. cone, nitric acid, until no more red fumes are evolved; then cool, saturate with ammonia, and filter. 2. Heat wax with 4 or 5 times as much nitric acid (sp. gr. 1.33) to boiling for one minute, then add an equal volume of cold water and an excess of ammonia if wax pure, the filtrate will be pure yellow; with resin, it will be blood-red or reddish-brown. The addi- tion of i per cent, of resin may be detected by this test. Donath (SULPHURIC ACID). Carbon disulphide is colored violet on boiling vinegar containing sulphuric acid with lead chro- mate, then filtering, and proceeding as in Donath 's test for free acid. Donath (TARRY MATTER). Ammonia containing tarry matter, on being supersaturated with sulphuric acid, reduces a solu- tion of potassium permanganate. Donath-Mayrhofer (GLYCERIN). When glycerin is present in a liquid a carmine color is produced on evaporating to dryness, carefully heating to 120 C. with 2 drops phenol and sulphuric acid, extracting with water, and adding ammonia to residue. Donath-Schmidt (RESIN IN WAX). Boil 5 Gm. wax with 20 to 25 Gm. crude nitric acid (sp. gr. 1.32-1.33) for i minute, add equal volume water, then excess of ammonia. Pour ammo- niacal fluid off if wax pure, color of latter is only yellowish; if even i% resin present, color will be more or less reddish- brown. Donne (Pus IN URINE). Add fragment of caustic soda to sediment collected in a conical glass by allowing to deposit and then pouring off the supernatant liquid, and stir pus is colored greenish and gelatinizes as a lumpy mass; a sedi- ment of mucus is partially dissolved with formation of a floccu- lent precipitate. Donny (LEGUMINOUS FLOUR IN WHEAT FLOUR). The moist- ened end of a glass rod bearing some of the flour is introduced into the vapors of nitric acid arising in a test-tube, after TESTS AND REAGENTS. 63 which the rod is introduced into an atmosphere of ammonia leguminous flour is thus colored a purple-red; wheat flour only yellow. Doutrelepont-Schutz (SYPHILIS BACILLUS STAIN). Place in solut. of fuchsine in i-% aq. solut. methylene- violet for 24 to 48 hours, decolorize in dil. HNO 3 (1:15) several seconds, place in 60- % alcohol 5 to 10 min., and when pale- blue place in weak, transparent aq. solut., safranine for a few minutes; the intensely red section is next placed in 60- % alcohol several seconds, then rinse in absol. alcohol for a. moment, dehydrate, clear in cedar oil, and mount in balsam. The bacilli are blue, the nuclei and tissue light-red, and round cells (Ehrlich's cells) are blue with red nuclei. Dragendorff (ALCOHOL IN VOLATILE OILS). Metallic sodium added to the oil in question generates hydrogen if alcohol is present, and produces a brownish color. Dragendorff (ALKALOIDS). Potassium and bismuth iodide. Bismuth iodide is heated with a potassium-iodide solution, the mixture filtered while hot, and to the filtrate an equal vol- ume of cold concentrated potassium-iodide solution is added. The concentrated solution is permanent, the dilute solution not. According to Frohn the reagent is prepared by suspend- ing 1.5 Gm. freshly precipitated bismuth subnitrate in 20 Gm. water, heating the mixture to boiling, and adding 7 Gm. potas- sium iodide and 20 drops hydrochloric acid. The reagent gives a reddish-brown precipitate with alkaloids, but also with albuminous bodies. Kraut's modification: Dissolve bismuth subnitrate, 80 Gm., in nitric acid, 200 Cc., and add solut. slowly to potassium iodide, 277 Gm., dissolved in little water. Cool quickly, filter from potassium nitrate crystals, and make up to i liter. Keep in the dark. See Mangini's and Thresh' s tests. Dragendorff (BENZIN; BENZENE). Benzene is distinguished from benzin by forming nitrobenzene by action of fuming nitric acid. Dragendorff (BILIARY PIGMENTS). See Gmelin's test. Dragendorff (CODEINE). Codeine dissolves in warm Frohde's reagent with yellowish, then deep-green, finally deep-blue color. 64 TESTS AND REAGENTS. Dragendorff (CURARINE). i. Particle dissolved in 2 to 3 Cc. dilute sulphuric acid (i : 50) gives on evaporating at 40 C. a handsome red color lasting i to 2 hours. 2. Add fragment of potassium bichromate to solut. of alkaloid in cone, sul- phuric acid a fine blue color develops, only gradually chang- ing to a long persisting red (with strychnine the red rapidly disappears). Dragendorff (DIGITALIN). i. Cone, sulphuric acid dissolves dig- italin, and solut. is brown-red, changing in 12 to 20 hours to cherry red; on exposure of solut. to bromine vapors it is col- ored violet-red. (Otto adds bromine water to sulphuric acid solut. with similar results.) On adding few drops water, per- manent green color develops. 2. Anhydrous chloral colors digitalin yellowish, then green; on warming to 60-70 C. violet; at higher temperature, deep blackish-green. 3. Few drops of digitalin solut. with few drops diluted solut. ox- gall and some cone, sulphuric acid gives handsome red color (other glucosides do also). Dragendorff (ELATERIN). With cone, sulphuric acid, elaterin gives at first a yellow, then handsome red color. Dragendorff (BRUCINE). Dissolve particle in io-% sulphuric acid and add a little very dilute potassium-bichromate solu- tion red to brownish-orange color develops. Dragendorff (NARCEINE). Zinc potassio-iodide affords a blue color. Dragendorff (NITROBENZENE). Add 4 drops alcohol and trace of sodium to 10 drops essential oil almond mixture becomes deep-brown and viscid if nitrobenzene present. Dragendorff (PHENOL IN URINE). Extract phenol by means of petroleum naptha, and test as usual. Dragendorff (SOLANINE). Firm jelly forms on dissolving sola- nine in hot amylic alcohol. Dragendorff (STRYCHNINE). lodic acid gives reddish-brown color with strychnine. Dragendorff (TURPENTINE). Essential oils containing turpen- tine become turbid on addition of alcohol. Draper (CASTOR OIL). Evaporate essential oil supposed to contain castor oil to a small bulk in a porcelain capsule, treat with one-fourth its original bulk nitric acid, subsequently TESTS AND REAGENTS. 65 neutralize acid solution with sodium carbonate solution by heating to boiling if castor oil present an odor like that of cenanthol is evolved. Drechsel (BILIARY MATTER). A red to reddish-brown color develops on adding to the concentrated liquid syrupy phos- phoric acid and a little cane sugar, and heating on a water- bath. See Pettenkofer's reaction. Drechsler (ALCOHOL). Add 3 drops of solution of i part potas- sium bichromate in 10 parts nitric acid (sp. gr. 1.30) to 5 drops of essential oil supposed to contain alcohol, and note change in color. Drewsen (ACETONE IN URINE). See Bayer's test. Drouin-Potain (CARBONIC OXIDE IN AIR). See Potain-Drouin. Drouot (MARGARIN IN BUTTER). Melt sample butter is transparent, margarin turbid. Bischoff has recently de- scribed an apparatus for this purpose (and Jahr also), whereby behavior of melted fat, when shaken with warm water, can be observed. Margarin rapidly separates from the water, whereas the butter is completely emulsified. Dryer (TIN). A purple color develops on adding to a liquid con- taining tin a few drops of a solution of o.i Gm. brucine, i Cc. of nitric acid, and 50 Cc. water heated to boiling-point and cooled. Dudderidge (PEROXIDES). Add silver-nitrate solut. to powder in test-tube if alkali peroxide present, oxygen evolved, recognized by glowing match-stick, and metallic silver depos- ited. With alkali earths reaction is slower, brown silver oxide being first deposited, changing to metallic (black) silver. Dudley (GALLIC ACID). A reddish color, changing to green, develops on adding a solut. ammonium picrate to gallic acid. Dudley (GLUCOSE). Dissolve bismuth subnitrate in a little nitric acid, add equal volume of acetic acid, and dilute solution with water to 10 times its volume. The urine to be tested is made alkaline, a few drops of the reagent are added, and the mixture boiled for 20 or 30 seconds if glucose present the reduced bismuth compound is deposited as a black precipitate. See Almen's and Boettger's tests. Duflos (ANILINE REACTION). With dilute sulphuric acid and a little lead- or manganese peroxide, aniline gives a greenish coloration. 66 TESTS AND REAGENTS. Duflos (FREE ACIDS). Evaporate loto 12 drops of acid solut. in a porcelain dish on water-bath, and add a fragment cane sugar free H 2 SO 4 gives greenish-black spot; free HC1 gives , brownish-black spot; free HNO 3 gives yellowish-brown spot. Duflos (PICROTOXIN). A green color develops on adding a solu- tion of potassium bichromate to picrotoxin. Dumontpallier (BILIARY PIGMENTS). This is Smith's modifi- cation of Marshal's test. Dumontpallier- Trousseau (BILIARY PIGMENTS). Add a few drops tincture iodine to the urine if biliary pigments pres- ent, an emerald-green color develops, even in dilute solutions. On overlaying the tincture on urine a green zone forms. Bromine water gives a similar reaction. Dunham (CLEARING MIXTURE). Mix 3 or 4 parts of white thyme oil with i part of clove oil. Dunham-Bujwid (ASIATIC CHOLERA BACILLUS). See Bujwid- Dunham. Dunstan - Ransom (ALKALOIDS IN BELLADONNA EXTRACT). Dissolve about 2 Gm. extract in water acidulated with hydro- chloric acid with gentle heat; filter, wash with dilute hydro- chloric acid until no alkaloidal reaction given by filtrate. Make the filtrate alkaline with ammonia, wash out twice with chloroform, shake out twice with acidulated water, again make alkaline, and remove alkaloid with two successive washings of chloroform, then evaporate the solvent, and dry at 100 C. Dunstan-Short (Nux-VoMiCA ASSAY). Extract 5 Gm. crushed nux vomica seeds by continuous percolation with 30 Cc. chlo- roform + 10 Cc. strong alcohol. Wash out twice with 25 Cc. dilute sulphuric acid. Make alkaline with ammonia water and wash out alkaloids with chloroform, then evaporate to dryness at 100 C. and weigh residue. Dunstan-Short (SEPARATION OF STRYCHNINE FROM BRUCINE). Dissolve 0.2 Gm. or less of mixed alkaloids of nux vomica in 10 Cc. dilute sulphuric acid (5-%), dilute solution to 175 Cc. with water, then make up to 200 Cc. with potassium-ferrocy- anide solution (5-%). Let stand 6 hours with occasional stir- ring, collect precipitate, wash with water acidulated with sul- phuric acid (0.25-%) until washings free from bitterness. The precipitate is then decomposed with strong ammonia, the TESTS AND REAGENTS. 67 filter washed with the liquid, and finally with chloroform, the ammoniacal solution being extracted with chloroform, and the solvent carefully evaporated in a tared flask, dried and weighed as strychnine. Dupasquier (ORGANIC MATTER IN WATER). Organic matter in water is shown by a bluish-violet color upon boiling with aqueous solution of gold chloride, due to reduction of the gold or by the formation of a gold mirror. Dupin-Crouzel (ANIMAL AND VEGETABLE FATS IN PETROLEUM). See Cr ouzel- Dupin. Dupre* (FOREIGN COLORING MATTERS IN WINE). A colorless io-% gelatin jelly is cut into cubes and allowed to stand in the wine for 24 hours. On removal the cube is cut in half. Nat- ural wine colors only penetrate short distance into the cube. Foreign colors dye it throughout greater part. Durien (CROTON OIL IN TINCTURE IODINE). Mix 10 Gm. tincture with 70 Gm. water, add iron filings in excess to the pptd. I, and shake the solut. when decolorized, with ether. Evaporate ethereal solut. and test residue (odor, action on skin, and brown color with H 2 SO 4 ). Durig (FORMALDEHYDE MIXTURE). A 3-% potassium-bichro- mate solution containing 4 to 6% formaldehyde. Dusart-Blondlot (PHOSPHORUS IN TISSUES). Treat substance with mixture of alcohol, ether and carbon disulphide contain- ing 0.5% sulphur, let stand i day. Repeat operation twice more, mix liquids, and warm with metallic copper. Collect copper (phosphide) and proceed as with Marsh's test. Duval (CARMINE AND ANILINE-BLUE METHOD). Stain with carmine, dehydrate sections, and stain for a few minutes in mixture of 10 drops saturated alcoholic solution aniline- blue with 10 Gm. absolute alcohol. Clear with turpentine without further treatment with alcohol, and mount in balsam. Duval (IMBEDDING PROCESS). Objects are imbedded in celloi- din solution or collodion, after thorough dehydration with absolute alcohol. Duval (UNROLLING SECTIONS). Float the rolled sections on the surface of warm water or alcohol in a watch-glass, or, place them on a layer of water on a glass slide, and heat the latter to 45 or 50 C. 68 TESTS AND REAGENTS. Duyk (GLUCOSE). Dissolve 5 Gm. nickel sulphate and 3 Gm. tartaric acid in 75 Cc. dist. water, and add 25 Cc. solut. NaOH (sp. gr. 1.33). In use, dilute with an equal vol. water, and add i or 2 Cc. of the saccharine solut. Heat to 100 C. the slightest quantities of glucose are indicated by a reddish- brown turbidity, increasing in intensity until in a few minutes a voluminous, dark reddish-brown, sometimes black, ppt. forms. Dwar (CINCHONA ALKALOIDS). Dissolve alkaloids in alcohol, and add one drop diluted sulphuric acid, followed by tincture iodine, drop by drop iodosulphates of the alkaloids are pre- cipitated, and are distinguishable from one another by differ- ence in appearance. Eber (DECOMPOSED SAUSAGE). Hydrochloric acid i; alcohol 3 ; ether i . A small piece of sausage is held over a few drops of reagent in a wide test-tube if sausage decomposed a cloud forms (due to ammonia). Ebner (DECALCIFICATION FLUIDS), i. 100 Cc. cold saturated aqueous solution sodium chloride, 100 Cc. water, and 4 Cc. hydrochloric acid. Preparations are placed in the fluid, and i to 2 Cc. hydrochloric acid added daily until they are soft. 2. 2.5 parts hydrochloric acid (sp. gr. 1.16), 500 of alcohol (90-%), 100 water, and 2.5 sodium chloride. Eboli (ALKALOIDS). Dil. sulphuric acid (i : i) and potassium bichromate give characteristic color-reactions. (See Am. Jour. Pharm., xxix, p. 369). Eboli (CANTHARIDIN). Heat solut. with sulphuric acid and potassium bichromate handsome green color develops if cantharidin present. Ebstein-Muller (PYROCATECHIN IN URINE). Add a few drops urine to a few drops very dilute ferric-chloride solut. in a watch-glass if pyrocatechin present, an emerald-green color develops. On contact with ammoniacal vapors the liquid becomes violet. On adding a trace of acetic acid to soiut. the emerald-green is restored. Edelmann-Braeutigam (HORSE MEAT). See Braeutigam-Edel- mann. Edlefsen (CHLORIC ACID IN URINE). Warm urine with its vol. cone, hydrochloric acid. The indican always present TESTS AND REAGENTS. 69 imparts a dark-red to brownish color, but at near the boiling- point any chloric acid present causes decolorization of the solut. to a light-brown or light-yellow color; solut. finally becomes colorless. If insufficient indican present, add a few drops indigo solut. Edlefsen (NAPHTALIN). i. A few drops ammonia water or sodium-hydrate solution causes fluorescence in a solut. con- taining naphtalin. 2 . Add 3 or 4 drops solut. calcium chloride and a few drops of cone, hydrochloric acid to liquid a lemon- yellow color develops. Extract this with ether and overlay extract on a i-% aqueous solut. resorcin, adding a little am- monia a bluish-green develops, changed by nitric acid to cherry-red. Edlefsen (PHENETIDIN IN URINE). Boil urine with hydro- chloric acid, cool, and add a few drops i-% solut. sodium nitrite. To one-half this mixture add a few drops 5-% solut. alpha-naphtol, and soda-lye to alkalinity a red color develops changing to reddish-violet with excess of hydrochloric acid. To other half of mixture add a few Cc. 3-% solut. carbolic acid, and soda-lye to alkalinity a yellow color develops changing to pale-red with excess of hydrochloric acid. Ehler (FIXING FLUID FOR ANNELIDS). Add i to 5 drops glacial acetic acid to 100 Cc. 0.5- to i-% chromic-acid solut. Ehrenbaum (IMBEDDING METHOD). Objects are penetrated by a mixture of ten parts resin and i part of wax. Sections are obtained by grinding in the usual way, and the imbedding mixture is afterwards removed by treating successively with turpentine and chloroform. Ehrlich (Acio HEMATOXYLIN). Dissolve hematoxylin, 2 Gm., in absolute alcohol, 100 Cc., and add glycerin, 100 Cc.; dis- tilled water, 100 Cc.; ammonia alum, 2 Gm.; glacial acetic acid, 10 Cc. Expose to daylight for at least a month before use, removing the stopper at intervals. Ehrlich (ACIDOPHILOUS MIXTURE), i. Indulin, aurantia, and eosine, of each 2 parts; glycerin, 30 parts. 2. Sat. aqueous solut. methyl orange G., 125 Gm.; sat. aqueous solut. fuch- sine S., 150 Gm.; sat. aqueous solut. methyl green, 125 Gm.; dist. water, 300 Gm.; glycerin, 100 Gm.; alcohol, 200 Gm. Preserve in amber-colored bottles. 70 TESTS AND REAGENTS. Ehrlich (AMMONIATED HEMATOXYLIN). Dissolve ammonium carbonate, 0.4 Gm., and hematoxylin, 2 Gm., in 50-% alcohol, 40 Cc., and expose to air in a shallow dish for 24 hours. Make up volume to 40 Cc. with 50-% alcohol (warming if necessary to re-dissolve any separated crystals), and add ammonia alum, 2 Gm., dissolved in distilled water, 80 Cc.; glycerin, 100 Cc.; alcohol, 80 Cc., and glacial acetic acid, 10 Cc. Ehrlich (DIAZO-REACTION). Test for pathologically changed urine by means of diazo-benzenesulphonic acid. Reagent is always freshly prepared as follows: (a) Sulphanilic acid, 5; hydrochloric acid, 50; distilled water, iooo;'(&) sodium ni- trite, 0.5; water, 100. For use add 6 Cc. of solut. b to 250 Cc. of solut. a. According to more recent statements a diazo-benzenesulphonic acid (1:60) is employed as Ehrlich's reagent. Pentzoldt (q.v.) utilizes the reaction for detection of glucose upon the addition of potassa. Ehrlich and others employ it for the diagnosis of various diseases (upon addition of ammonia), especially for the de- tection of biliary pigments. Urine is tested according to dif- ferent methods: i. Equal volumes of urine and reagent are mixed, and ammonia (one-eighth volume) added. In cases of typhoid, pneumonia, and measles, solution assumes a red color readily recognizable in the foam when solut. is shaken. 2. In Charlie's modification, for detection of biliary pigments, Ehrlich's reagent is added to urine diluted with an equal vol. dil. acetic acid. The resulting dark color is converted into violet by glacial acetic or other acid. 3. The urine to be tested is shaken with chloroform, and i to 2 volumes of Ehr- lich's reagent added with sufficient alcohol to make the mix- ture homogeneous. If bilirubin present a red color develops, which on careful addition of cone, hydrochloric acid changes to violet and blue. Upon addition of potassa solution three zones form, a greenish-blue lower one, a pure blue upper zone, and a reddish band between. Ehrlich (DAHLIA STAIN). Add to an aqueous solut. of dahlia 5% acetic acid; or, stain in a neutral solut. and wash out with acidulated water. Dehydrate with alcohol and mount in resin-turpentine solution. TESTS AND REAGENTS. 71 Ehrlich (GENTIAN-VIOLET SOLUTION FOR STAINING BACTERIA). i. Shake 4 Cc. aniline with 100 Cc. distilled water, and separate undissolved aniline by filtration through a moist filter. To filtrate add n Cc. cone, alcoholic solut. gentian violet while shaking, and let mixture stand for 24 hours. 2. Gentian violet, i part; alcohol, 15 parts; aniline, 3 parts; water, 80 parts. Ehrlich ("MASTZELLEN "). An almost saturated solution of dahlia in the following mixture: Absolute alcohol, 50 Cc.; water, 100 Cc.; glacial acetic acid, 12.5 Cc. Tissues are well hardened in strong alcohol, placed for at least 12 hours in the above, then washed out in alcohol, and mounted in resin- turpentine solution. Ehrlich (STAINING METHOD). Use a saturated aqueous solut. aniline as a mordant, the dye being dissolved in this or added in the form of a cone, alcoholic solut. till a slight opacity appears. Ehrlich ("TRIACID" MIXTURE). Mix saturated solutions of orange G., 120 parts; acid fuchsine, 80 parts, and ethyl green, 100 parts; then add distilled water 300 parts; absolute alcohol, 1 80 parts; glycerin, 50 parts. Ehrlich-Biondi [Ehrlich- Biondi-Heidenhain} (STAIN), (a) Me- thyl green, 0.5 Gm.; distilled water, 100 Cc.; (6) acid fuch- sine, 0.5 Gm.; distilled water, 40 Cc.; (c) orange, 2 Gm. ; dis- tilled water, 200 Cc. Mix the three solutions and filter before use. Stain sections for 12 hours, then wash, dehydrate, clear, and mount. Ehrlich-Biondi-Heidenhain. See Ehrlich-Biondi. Ehrlich- Weigert- Koch (ANILINE WATER). Mix 100 Cc. aniline- water (i : 30) with ii Cc. cone, alcoholic solut. gentian violet, methyl violet, or fuchsine, and 10 Cc. absolute alcohol. Einbrodt (AMMONIUM SALTS). Solut. mercuric chloride made slightly alkaline with potassium hydroxide or carbonate pro- duces a white turbidity or ppt. with ammonium salts. Einhorn (SUGAR IN URINE). Formation of carbonic acid upon treating urine with yeast is certain indication of glucose in urine. Einhorn and others (v. Arndt} have constructed special fermentation saccharometers, which permit exact quantitative estimations. 72 TESTS AND REAGENTS. Eiselt (MELANIN IN URINE). Urine containing melanin ac- quires a dark color on treatment with oxidizers (e. g., nitric acid alone or with potassium bichromate and H 2 SO 4 ). Eisig (FIXING SOLUTION). Mix equal parts of 0.25-% plati- num-chloride solut. and i-% chromic-acid solut. Pelagic fish ova are left in this for i or 2 days. Eismond (QUIETING INFUSORIA). Add to water containing the organisms a drop thick aqueous solut. of cherry-tree gum. Elias (ALKALOIDS). Formaldehyde-sulphuric acid gives the following various color reactions with alkaloids: Narcotine, violet, changing to olive-green and finally yellow; papaverine , wine-red, changing from the margin inwardly to yellow and finally deep-orange. Elram (ETHEREAL OILS, AND RESINS). A i-% solut. vanillin in sulphuric acid gives color reactions as follows: Maracaibo bals. copaiva intensely dark orange-red color, margins violet, and color changing slowly to violet ; Gurjun balsam a similar color, but without the violet, and changing in 2 to 4 hours to dark-brown; oil copaiva reddish-violet changing rapidly to dark reddish-brown; copaivic acid like Maracaibo copaiva; colophony a reddish-brown, changing to bluish- violet ; cam- phor pink, changing in 24 hours through red, reddish- violet and dirty gray. Elsching (CELLOIDIN SOLUTION). Allow celloidin shavings to swell for 24 hours in necessary quantity absolute alcohol, then add proper amount of ether. Em den, Van- (DUBOISINE). Solut. bromine in potassium- bromide solut. gives yellow ppt. with dil. solut. duboisine; iodopotassium iodide gives brownish-red ppt.; sodium phos- phomolybdate gives voluminous ppt., soluble on warming, and reprecipitated on cooling; solut. of sodium phospho- molybdate in nitric acid gives yellow ppt. Emery (AQUEOUS CARMINE INJECTION). Add acetic acid to a io-% ammoniacal solut. carmine with continual stirring, until mixture becomes blood-red. Pour off supernatant clear solut. and inject cold without further preparation. Enell (GURJUN OIL IN COPAIVA). Add 8 drops of balsam to be tested to mixture of 2 drops cone, sulphuric acid and 4 Cc. acetic acid no red or violet color should develop within 15 TESTS AND REAGENTS. 73 minutes, and on addition of i drop water, no red ppt. should form on shaking. Endemann-Prochazka (COPPER). Add i drop cone, hydrobro- mic acid to i drop of solut. of salt or ash in a watch-glass on standing for some time, a rose-red to reddish-brown color is developed by minutest trace of copper. Engel (CREATININE). i. Add a little silver-nitrate solut. to creatinine solut., then potassa-lye by drops white ppt. forms, soluble in excess of KOH ; becomes gelatinous and blackens gradually in the cold, quickly on heating. 2. To a cold solut. creatinine containing potassa, add cold solut. mercuric chloride the compound C 4 H 7 HgN 3 O 2 is obtained. Engel- Ville (INDICATOR). Poirrier Blue C^B. Gives with car- bonates a blue color; with caustic alkalies, a red; and with acids a blue color. Entz (METHOD FOR INFUSORIA). Add a few drops Kleinen- berg's liquid to a watch-glass water containing the organisms. Remove liquid after i or 2 minutes, and wash objects for half- an-hour with alcohol of medium strength; then stain 10 to 20 minutes in picro-carmine solution, wash with water till picric acid is removed, and mount in a mixture of equal parts glyc- erin and water. Erdelyi (FOREIGN FATS IN BUTTER). A solut. of 2 Gm. of the fat in 6 Cc. cumene remains unchanged at o C. for at least an hour if fat is pure butter. Erdmann (ALDEHYDES). Dimethylhydro-resorcin affords with aldehydes crystallizable insoluble compounds, which may be identified by analysis and melting-points. Erdmann (ALKALOIDS), i. Mix 6 drops nitric acid (sp. gr, 1.25) with 100 Cc. water, and add 10 drops of this solut. to 20 Cc. pure cone, sulphuric acid. 2. Dilute 10 drops nitric acid (sp. gr. 1.185) with 20 Cc. of water, and add 20 drops of this solut. to 40 Cc. pure cone, sulphuric acid. Add i Cc. of the reagent to i to 2 Mg. of the dry alkaloid in a watch-glass on white paper or in a white porcelain dish, and set mixture aside for J- to \ hour ati8to22C. For color reactions, see Hager, Pharm. Praxis, 1886, I, p. 208. Erdmann (POTASSIUM AND RUBIDIUM). Sodium-cobalt ni- trite is a sensitive reagent for potassium and rubidium. Re- 74 TESTS AND REAGENTS. agent is prepared by dissolving 30 Gm. cryst. cobalt nitrate in 60 Cc. water, and adding 100 Cc. cone, solut. NaNO 2 ( = 50 Gm. NaNO 2 ) and 10 Cc. glacial acetic acid. Sensitive to i : 10,000 K. Free mineral acid or acetic acid must be absent. Erdmann-Uslar (ALKALOIDS). Extract with water acidulated with hydrochloric acid, mix with sand, treat with ammonia, and then extract with amylic alcohol. For details see Am. Journ. Pharm., xxxiv, p. 354. Erlicki (HARDENING FLUID). 2.5 Gm. potassium bichromate; 0.5 Gm. copper sulphate; 100 Cc. water. Ermengen, Van- (STAINING CILIA AND BACTERIA). Spread cultivations thinly on a clean glass cover, and place for hour if cold, or 5 minutes at 50 C., in fixing solut. (2-% osmic-acid solut. i ; 10- to 25-% tannin solut. containing 4 to 5 drops acetic acid per 100 Cc., 2). Then wash with water and alcohol, put in sensitizing bath (gallic acid 0.5 Gm.; tannin 3 Gm.; fused sodium acetate, 10 Gm.; water, 350 Gm.); and finally wash with plenty water, and dry between filter -paper. Bacteria appear blackish-brown ; cilia pure black. Ernst (BACTERIA NUCLEAR STAIN). Stain with warm, not hot, alkaline methylene-blue solut., wash in water, and after- stain in cold Bismarck-brown solut. Nuclei (sporogenous spots) stain blue-black, thus differentiating from light-blue stained spores. Ernst (SPORE STAIN). The cover-glass preparation, while still warm from being passed thrice through flame, cover with as much as possible of LoefHer's strongly alkaline methylene- blue solut. Then pass over blue flame of a Bunsen burner until steam arises from it, but do not allow to boil. Rinse in water, and double stain in Bismarck-brown solut. for i to 2 minutes, or in very dilute fuchsine solut. Spores are stained blue. Errera (EXTRACTION OF ALKALOIDS). 5-per-cent. alcoholic tar- taric-acid solution. Esbach (ALBUMIN), i. 10 Gm. picric acid; 20 Gm. citric acid; i liter water. In albuminous solutions (urine) reagent produces, upon previous addition of acetic acid, a yellow ppt. Amount of latter, which can be approximately estimated in TESTS AND REAGENTS. 75 the albuminometer, serves also for quantitative estimation of albumin. 2. Solut. picric acid (10.5 to 1,000) 8 vol., acetic acid (sp. gr. 1.04), i vol. Mix 20 Cc. urine with 20 Cc. solut., heat on water-bath, filter, wash ppt., dry, and weigh; 0.8 of ppt. represents albumin. For Esbach's ureometer, see Huef- ner's test. Esbach-Gawalowsky (ALBUMIN IN URINE). See Gawalowsky. Eschbaum (SUGAR IN URINE). Place about equal quantities (size of a pea) of phenylhydrazine, HC1, and cryst. sodium ace- tate in a test-tube, fill with urine, shake until salts dissolve, then place in boiling water, removing heat at once. Allow to cool in the water, preferably over night, then collect ppt. with a pipette and examine crystals microscopically. o.oi-% sugar may be detected. Eschka (MERCURY). Heat substance in crucible, and condense vapors on a cold glass plate a white stain is left if mercury was present. Estcourt-Parry (RESIN, PARAFFIN, AND STEARIN IN WAX). Boil 5 Gm. wax with 20 Gm. nitric acid, cool, dilute with ammonia water if resin present, an intense red develops. Wax containing paraffin requires less caustic potassa for saponification than does pure wax; if stearin present, more caustic potassa is required. Eulenstein (CEMENT). Mix equal parts of Brunswick black and gold size with a very little Canada balsam. Everard-Demoor-Massart (HEMATOXYLIN-EOSINE). Dissolve alum, 20 Gm., in water, 200 Gm., with heat, then filter, and after 24 hours add a solut. of hematoxylin, i Gm., in alcohol, 10 Gm. Let solut. stand for 8 days, filter, and mix with equal vol. of the following solut.: Eosine, i Gm.; alcohol, 25 Gm.; water, 75 Gm.; glycerin, 50 Gm. Everitt (OPIUM). Red color caused by ferric chloride in solu- tions containing opium is not affected by mercuric chloride. Iron sulphocyanate solution is decolorized under similar cir- cumstances. Ewald (HYDROCHLORIC ACID IN GASTRIC JUICE). Mohr's solut. (q. v.) diluted with 3 vol. of water. Place a few drops with i or 2 drops gastric juice in a porcelain dish if hydrochloric acid present, a faint violet color appears at point of con- 76 TESTS AND REAGENTS. tact of liquids, and on stirring, mixture becomes brown. See also Siewer's test. Eyclesheimer (CLEARING MIXTURE). Equal parts bergamot oil, cedar oil, and carbolic acid. Eykmann (PHENOL). A very dilute phenol solution gives, upon addition of a few drops spirit nitrous ether, and overlaid on cone, sulphuric acid, a red zone-reaction. Eykmann (THYMOL IN MENTHOL). Dissolve a little of the substance in i Cc. glacial acetic acid, add 5 or 6 drops sul- phuric acid, then i drop nitric acid thymol indicated by blue color. Fabre-Domergue (GLUCOSE MEDIUM). Mix glucose syrup (sp. gr. 1.1968) 1,000 parts, methyl alcohol 200 parts, glycerin 100 parts, and saturate with camphor. If acid, the medium should be neutralized with potassa or soda. Fabris-Villavecchia (SESAME OIL). 2 Gm. furfurol dissolved in 100 Cc. alcohol. Add o.i Cc. of solut. to 10 Gm. of oil with i Cc. hydrochloric acid, shake, then add 10 Cc. chloroform. The oil dissolves in the chloroform, and the aqueous layer, even if less than i% sesame oil had been present, acquires a handsome carmine-red color. If sesame oil absent, no color develops; if rancid olive oil present, a greenish color forms. Reaction very sensitive and characteristic. Faby (CODEINE). Rub trace of codeine with 2 drops solut. sodium hypochlorite, and add 4 drops cone, sulphuric acid a blue color develops. Fages (CHLORATES AND BROMATES). Add to i Cc. solut. strychnine nitrate in 24 Cc. HNO 3 sp. gr. 1.330 a few drops of a solut. of a chlorate or bromate, and concentrate solut. a red color develops, either at once, or within 15 to 20 minutes, i drop of a solut. containing o.i Mg. KC1O 3 gives the reac- tion in 5 minutes. For details see MERCK'S REPORT, x, p. 120. Fairbanks (PHOSPHORUS IN IRON). Test solut. is a filtered solution of molybdic acid 100 Gm., water 400 Cc., and am- monia 80 Cc., added to a mixture of nitric acid (sp. gr. 1.42) 300 Cc. and water 700 Cc. Fairthorne (CHLORAL). Blue color forms on heating chloral with cone, solut. potassium bichromate and adding nitric acid. TESTS AND REAGENTS. 77 Fairthorne (MORPHINE). Dark-red color develops on adding to morphine a solut. of sodium hypochlorite and then ammonia. Faktor (REAGENT). Sodium thiosulphate gives the following reactions: I. BY THE DRY WAY Manganese Salts. On ignition with thiosulphate they suffer intumescence, and yield MnS soluble in acids, and also evolve H 2 S. Antimony Salts. On being heated with the reagent they afford an orange-red mass which on further ignition becomes blackish-gray and becomes superficially coated with a white layer of oxide. Cadmium Salts. These, on ignition, afford at first a yellow sulphide which later becomes brownish-red, and on cooling, again yellow. Stannous Salts. These on being heated with the reagent afford a dark-brown sulphide. Potassium Chr ornate s. These give a green to brownish- green chromic oxide. II. BY THE WET WAY Thallium Salts. In alkaline solution and at the ordinary temperature they give a white ppt. soluble on heating. On adding acetic acid to the solution black T1 2 S ppts. Molybdenum Salts. These afford no reaction; on adding HC1 however, a dark-blue ppt. forms. Tungsten Salts. On heating these give with thiosulphate no color reaction. On adding HC1, however, a white ppt. forms while the fluid acquires a blue color. If HN0 3 is added instead of HC1 the liquid becomes dark-blue. Chromic Acid affords with the thiosulphate a brown ppt., while the liquid is colored yellow from the chromate formed. Mercuric Oxide gives a ppt. of black sulphide on warming with the reagent. Mercuric Sulphide on warming with thiosulphate acquires a fiery-red color. Minium acquires a darker color on being warmed with thiosulphate solution. 78 TESTS AND REAGENTS. Falk (BLOOD). Add water to a mixture of alcohol 20 Gm., chloroform 20 Gm., oil turpentine containing ozone 20 Gm., and acetic acid 2 Gm., till permanent turbidity, then triturate solut. with a little guaiac resin. Reagent gives a blue color with blood. See also Almen's test. Paris (GLYCERO-GUM). Acacia, 2 oz.; glycerin, ijoz.; water, ii fl. oz. ; thymol, i Gm. Dissolve with heat and filter. Farrant (MEDIUM). According to Squire dissolve acacia, 130 Gm., in a- solut. arsenous acid, i Gm., in distilled water, 200 Cc., with frequent stirring, then add glycerin, 100 Cc., and filter through fine Swedish paper, upon which has been de- posited a thin layer of talc. Sometimes i% formic acid (sp. gr. 1.2) is added. Altschul says the medium should consist of i part acacia, i of glycerin, and i of cone, aqueous solut. arsenous acid. Faulding (CINEOL IN EUCALYPTUS AND CAJUPUT OILS). Add 10 or 20 Gm. of oil to phosphoric acid (sp. gr. 1.75) gradually added with constant stirring till no more solidification occurs and slight color appears. Press magma strongly between filter -paper, transfer dry cake to a graduated cylinder, add water, and measure or weigh cineol which separates. Faure (NATURAL WINE COLORING MATTER). If 10 drops of a 2-% tannin solut. and 6 drops of a 2-% gelatin solut. are added to 2 Cc. red wine, the natural coloring-matter of wine is completely precipitated; coal-tar dyes remain in solution. Fayolle"-Villiers (ALDEHYDES AND KETONES). See Villiers- Fayolle. Fehling (SUGAR, AND OTHER REDUCING SUBSTANCES), a. Dissolve 34.669 Gm. crystallized, not effloresced, copper sul- phate in water and dilute solut. to 500 Cc. b. Dissolve 173 Gm. crystallized Rochelle salt and 50 Gm. caustic soda in sufficient water to make 500 Cc. Mix equal vol. of a and b, dilute with 5 parts of water, heat to boiling, and gradually add sugar solution (about i-% strength) decolorization takes place, red cuprous oxide being precip- itated. 10 Cc. Fehling's solution are reduced by 0.05 Gm. grape sugar, 0.067 Gm- milk sugar, 0.0475 Gm. cane sugar, and 0.045 Gm. dextrin or starch, the last three having been previously inverted by boiling with a dilute mineral acid. It TESTS AND REAGENTS. 79 must be remembered, however, that many other substances also reduce Fehling's solution. According to an older formula, Fehling's solution was pre- pared as a single solution, and had to be freshly prepared for use each time, as the single solution does not keep long. So- lutions identical with or similar to Fehling's reagent are Barreswil's, Frommherz's, Trommers', Violette's and Worm- Mueller's solutions (q. v.). Fenton (TARTARIC ACID). Tartaric acid gives a violet color on addition of solut. ferrous chloride or sulphate with i or 2 drops hydrogen dioxide and excess of free alkali. Ferraro (RESORCIN; SANTONIN; VERATRINE). A little of the substance is burned in a glass saucer with a few drops sul- phuric acid and alcohol in excess. Santonin residue is uni- form and a characteristic brick-red; resorcin residue at first olive-green, changing quickly to light blood-red with charac- teristic yellow zones; veratrine residue is uniform violet- red. (For details see Merck's Report, vol. iv, p. 10.) Ferreri (PHLOROGLUCIN MIXTURE). Dissolve phloroglucin, i Gm., in hydrochloric acid, 10 Gm., and water 100 Gm., with heat, and after cooling add 200 Gm., 70-% alcohol. Ferrier (BLOOD). Dissolve fuchsine, i Gm., in distilled water, 150 Cc., and rectified spirit, 50 Cc., then add 200 Cc. glycerin. Fiebig (SUGAR ESTIMATION BY FERMENTATION GLUCOSOME- TER). See Einhorn's test. Field (BISMUTH). Solutions of lead salts containing trace of bismuth afford an orange-red or crimson ppt. (in scales) instead of a yellow one on adding potassium-iodide solut. Filhol (ALKALIES). Sodium nitroprussiate in the presence of sulphuretted hydrogen gives a blue color with alkalies. Filhol (IODINE). Evaporate solut. to dryness with potassa, take up with alcohol, again evaporate, dissolve residue in water, add a few drops hydrochloric acid, then some chromic acid on now shaking with carbon disulphide, latter is colored violet. Filsinger (BUTTER). Same as Drouot's test (q. v.). Filsinger (CACAO OIL). Modified ether test. Shake 2 Gm. of the oil in a graduated tube with 6 Cc. of a mixture of 4 parts ether (sp. gr. 0.725) and i part alcohol (sp. gr. 0.810) and set 8o TESTS AND REAGENTS. aside pure oil yields a clear solut. that does not become turbid at o C. Finkelburg (EXCREMENTS IN SOIL AND WATER). Alkaline solution of silver oxide with sodium thiosulphate. When substances containing excrements are boiled with hydro- chloric acid for several minutes, then make alkaline with soda and again heated to boiling with the reagent, a dark reddish- brown ppt. forms, while the solut. remains light-brown in color. Finkener (ADULTERATIONS IN CASTOR OIL). 10 Cc. oil are shaken with 50 Cc. alcohol (sp. gr. 0.829) and 17.5 C. if turbidity develops which does not disappear when mixture is heated to 20 C., at least 10% foreign oils are present. Finkle (CHRYSAMMIC ACID). Chrysammic acid gives a violet- red color on adding warm solut. potassium cyanide, potassium carbonate in excess, and water. Finzelberg (VALERALDEHYDE IN VALERIANIC ACID). Mix 2 Gm. valerianic acid with 3 Gm. ammonia water, add 150 to 200 Cc. water, and shake vigorously if acid is pure, a perfectly clear solution results; if valeraldehyde present, solut. is opalescent. Flora (PHENOL). If an excess of phenol is triturated with oil peppermint, a bluish-green color develops after a time, and disappears on warming, but reappears on cooling. Creosote, guaiacol, resorcin, and other allied bodies do not give the reaction. Fischer (ALDEHYDES, KETONES, AND CARBOHYDRATES). With phenylhydrazine difficultly soluble condensation products are formed. To test for sugar in urine, 50 Cc. of latter are heated with 2 Gm. phenylhydrazine hydrochlorate and 4 Gm. sodium acetate for ^ to i hour on a water-bath phenyl- glucosazone is precipitated. If ppt. is dissolved in alco- hol, water added, and the alcohol evaporated, needles of the glucosazone melting at 204 to 205 C. are obtained. Fischer (HYDROGEN SULPHIDE). A blue color forms on adding to 50 Cc. of a liquid containing hydrogen sulphide i Cc. hydro- chloric acid, followed by a few grains of para-amidodi- methylamine sulphate, and one or two drops of a dil. solut. ferric chloride. TESTS AND REAGENTS. 81 Fischer (PLATINUM). Stannous chloride imparts a red color to a solut. of platinum chloride in hydrochloric acid. Fischer (SELENIUM) . On applying to silver a solution of selenous acid mixed with sulphuric acid, a yellow to brown spot develops. Fischer (SOAP IMBEDDING MASS). Dissolve 15 parts trans- parent soap in 17.5 parts 96-% alcohol. Fischer (STAINS FOR CILIA OF BACTERIA). See Loeffler's stain. Fischer- Phillip (INDICATOR). Dimethylamidoazobenzene ; it gives a yellow color with alkalies, and a red with acids. Fittig (INDICATOR). An ethereal solution of mesityl-quinone is changed from yellow to violet by alkalies. Fleck (AMMONIA IN WATER). Impregnate strips of white filter- paper with a io-% solut. lead acetate, and dry in atmos- phere free from sulphuretted hydrogen. Fleischl (BILIARY PIGMENTS). See Gmelin's test. Fleischmann (ALCOHOL). If alcohol present in essential oils or chloroform, a green color develops on shaking well with water, evaporating the aqueous liquid, treating with solu- tion of potassium bichromate, and adding an excess of sul- phuric acid. Fleitmann (ARSENIC). The dil. acid in Marsh's test is replaced by a strong solut. of potassium- or sodium hydroxide, and the arseniuretted hydrogen evolved produces a black stain on paper impregnated with silver nitrate. Fleitmann (COPPER). The copper solution, freed from nitric acid, bismuth, or lead, is precipitated with metallic zinc, and ' the ppt. collected, washed, and dissolved in a mixture of ferric chloride and hydrochloric acid. The ferrous chloride formed is titrated with potassium-permanganate solution. Each atom of ferrous iron (56) = 3i-5 of copper. If the original solution contains nitric acid, bismuth, or lead, the reduction by zinc must be made in the ammoniacal filtrate from the precipitates of these metals ; the zinc should be in the form of dust and the solution warmed. When reaction is complete the blue color will have disappeared. The precipitate is then washed with hot water, then with weak hydrochloric acid to remove the zinc, then dissolved in acid and ferric chloride, and titrated as before. 82 TESTS AND REACENTS. Flemming (FIXING AND HARDENING SOLUTIONS). Chromo- acetic acid is an aqueous solut. of chromic acid, 0.2- to 0.25-% and acetic acid, o.i-%. Weaker chromo-aceto-osmic acid is an aqueous solut. of chromic acid, 0.25-%; osmic acid, o.i-%; glacial acetic acid, o.i-%. The strong solut. consists of i-% chromic acid solution, 15 parts; 2-% osmic acid, 3 parts; glacial acetic acid, i part. Picric acid has sometimes been substituted for chromic acid. Squire gives the following formula: Osmic acid (i-% solut.), 80 Cc.; chromic acid (io-%), 15 Cc.; glacial acetic acid, 10 Cc.; distilled water, 75 Cc. Flemming (GENTIAN- VIOLET METHOD). Use an alcoholic solut. diluted with about one half its bulk of water. Differ- entiate stained objects in alcohol containing about 0.5% hydrochloric acid, followed by pure alcohol and clove oil. Flemming (GLYCERIN PRESERVATIVE). Equal parts of alcohol, glycerin, and water. Lee recommends addition of 0.5 to 0.7% acetic acid. Flemming (ORANGE METHOD). Stain for days or weeks in strong alcoholic safranine solut. diluted with half its bulk aniline water (saturated); then rinse in distilled water, differ- entiate in absolute alcohol containing 0.1% hydrochloric acid, stain for i to 3 hours in strong aqueous gentian- violet solution fc again wash in distilled water, and finally treat with concentrated aqueous solution of orange G. After a few minutes transfer section to absolute alcohol, then clear in clove- or bergamot oil, and mount as usual in dammar or balsam. Flemming (SAFRANINE SOLUTION). A concentrated solut. in absolute alcohol, diluted with about one-half its bulk water, as above. Follow the same after-treatment. Flesch (CHROMO-OSMIC ACID). Osmic acid, o.i Gm.; chromic acid, 0.25 Gm.; water, 100 Gm. Flueckiger (ACETANILID). Solutions containing acetanilid give with solut. potassium hydrate and chloroform the disagree- able odor of phenyl isocyanide. Flueckiger ( ACIDS). Free mineral acids decolorize a violet- colored mixture of ferrous sulphate, gallic acid, and sodium acetate. TESTS AND REAGENTS. 83 Flueckiger (ARSENIC). Solut. mercuric chloride is employed in place of the silver nitrate used according to Gutzeit (q. v.). With this modification arseniuretted hydrogen produces a yellow spot, darkened by water, but permanent toward alco- hol. Very dilute antimony hydride does not affect the mer- curicchloride. Somewhat less diluted it produces a brown spot, which disappears upon addition of alcohol if sufficient mercuric chloride was on the test-paper. Flueckiger (BRUCINE). A crimson color is produced on mixing an aqueous solut. of brucine with mercurous-nitrate solut. free from excess of acid, and heating. Flueckiger (COLCHICINE). A very dilute and almost colorless solut. colchicine is colored yellow by sulphuric acid, and bluish- violet by nitric acid. Flueckiger (CREOSOTE; PHENOL), i. On mixing i volume of ferric-chloride solut. (sp. gr. 1.34) with 9 of creosote and adding 5 of alcohol (85-%), a green color is produced; the solut. becomes cloudy and brownish on adding 60 volumes water. Phenol or a mixture in considerable proportion with creosote gives a brown color with the alcohol, changing to blue on adding water. 2. Croesote gives a brown or dirty green color on adding one-fourth its bulk ammonia and exposing to vapor of bromine; phenol causes a blue color under simi- lar conditions. Flueckiger (CURARINE). A dark-blue color is produced on precipitating curarine with potassium bichromate and adding sulphuric acid to the dried precipitate. Flueckiger (DIGITALIN). An alcoholic solut. chloral dissolves digitalin with a yellowish- green color which, on heating, changes first to violet, then to blackish-green. Flueckiger (ESSENTIAL OILS). The reaction lasts longer, and its violence is diminished on applying the sulphuric acid test, if the oils be previously diluted with 6 to 10 volumes of carbon disulphide. Flueckiger (EUPHORBIUM). On extracting euphorbium with ether, evaporating, and adding sulphuric acid, a yellowish- brown color is produced, which changes to violet on adding nitric acid. Flueckiger (GALLIC ACID). On adding to gallic acid a freshly 84 7S7"5 AND REAGENTS. prepared aqueous solut. ferrous sulphate (i: 100), and adding sodium acetate, the mixture turns violet. Flueckiger (GURJUN OIL). On dissolving 15 drops copaiba containing gurjun oil in twenty times its bulk carbon disul- phide, and adding i drop of cooled mixture of equal volumes sulphuric and nitric acids, a violet color will develop. Flueckiger (DIFFERENTIATING NAPHTOLS). If 0.2 Gm. naphtol is shaken with 0.2 Gm. mercuric chloride, o.i Gm. nitric acid and 10 Cc. water at 100 C., alpha-naphtol is indicated by a slight scarlet-red precipitate; beta-naphtol by a volu- minous reddish-brown ppt. Flueckiger (PEPPERMINT OIL), i. A bluish-green color de- velops on adding fused salicylic acid to peppermint oil; the addition of alcohol gives a solut. which is blue by transmitted light, red by reflected light. 2. The addition of i drop nitric acid (sp. gr. 1.20) to 50 drops peppermint oil causes fluores- cence after several hours. 3. The reddish color produced on adding chloral hydrate to peppermint oil is intensified by H 2 SO 4 , and changed to dark violet on adding chloro- form. Flueckiger (PHENOL IN CLOVE OIL). Shake the oil with fifty times its volume of hot water, cool, decant the oil and concen- trate the aqueous liquid by evaporation. On adding to the residue a drop of ammonia solution and sprinkling on the surface a little chlorinated lime, a green to blue color develops if phenol present. Flueckiger (QUININE), i. Bromine water and an excess of ammonia added to a solution of quinine give an emerald-green color. j(Thalleioquin reaction.) See Brand's test. 2. Chlorine water, potassium ferricyanide and ammonia produce a red color with quinine. 3. A ray of light passing through an acid solution of quinine has a bluish color. Flueckiger (TEST PAPER). Sublimate Paper. Paper impreg- nated with HgCl 2 gives with arseniuretted hydrogen a yellow, then a brown, color. Flueckiger (VALERIAN OIL). A blue color is produced on dis- solving i drop valerian oil in 15 drops carbon disulphide, and adding i drop sulphuric acid, followed by i drop nitric acid (sp. gr. i. 20). TESTS AND REAGENTS. 85 Flueckiger-Behren (SESAME OIL). Five drops sesame oil when treated with 5 drops of a cooled mixture of equal parts cone, sulphuric acid, nitric acid and water, produce a green zone. Upon immediate addition of 5 drops carbon disulphide an upper greenish layer is produced, which fades more slowly than the original color. Foa (FIXING LIQUID). Equal parts saturated solut. mercuric chloride in normal-salt solut. (0.75-%) and Mtiller's solution or 5-% bichromate solut. Foa (HEMATOXYLIN AND SAFRANINE STAIN). Distilled water, 100 parts; Boehmer's hematoxylin solution, 25 parts; i-% solut. safranine in water and alcohol, 20 parts. Focke (GLUCOSE). See Trommer's test. Foettinger (NARCOTIZATION METHOD). Drop crystals of chlo- ral hydrate into the water (0.25 to 0.80 Gm. to each 100 Cc.) containing the organisms. Fokker (URIC ACID). In urine containing uric acid, and pre- viously made alkaline with soda, solut. of ammonium chloride causes formation of the difficultly soluble ammonium urate. This test serves also, particularly in Salkowsky's modification, for quantitative estimation. Fol (ALBUMIN FIXATIVE). Filter whipped white of egg through a Bunsen filter, then add an equal bulk of glycerin and a little camphor or carbolic acid. Fol (BERLIN-BLUE GELATIN MASS), a. 120 Cc. cold saturated solution of ferrous sulphate and 300 Cc. warm gelatin solution; b. 600 Cc. gelatin solution, 240 Cc. of a saturated solut. oxalic acid, and 240 Cc. cold saturated solution of potassium ferri- cyanide. Pour a into b gradually with vigorous shaking, and warm the whole for 1 5 minutes on a boiling water-bath. Then allow mass to set, press out into strings through tulle or fine netting, wash strings, and spread out to dry on para- fined parchment paper. When required for use, soak in cold water for a few minutes, and then warm with enough oxalic acid to enable it to completely dissolve. Fol (CARMINE-GELATIN MASS). Macerate sheet gelatin for 2 days in concentrated ammoniacal carmine solution (strong solut. ammonia, i part; water, 3 or 4 parts; carmine, to satu- ration. Filter.); then rinse and put for a few hours into 86 TESTS AND REAGENTS. water acidulated with acetic acid. Wash well on a sieve with running water for several hours to remove excess of acid or ammonia, melt, and pour on to large sheets of parchment paper soaked with paraffin, which are hung up to dry in an airy place. When dry separate gelatin, cut into long strips, and protect from dust and damp. When required for use soak for a few minutes in water and melt on a water-bath. Fol (DECALCIFICATION LIQUID). Mix 70 volumes of i-% chromic acid solut., 3 of nitric acid, and 200 of water. Fol (FERRIC-CHLORIDE FIXING AND STAINING PROCESS). Preparations are treated with tincture of ferric chloride di- luted with 5 to 10 times its bulk of 70-% alcohol, and then transferred for 25 hours to alcohol containing a trace of gallic acid. Fol (FIXING SOLUTION). Mix psmic acid (i-% solut.), 4 Cc.; solut. chromic acid(io-%), 5 Cc.; glacial acetic acid, 10 Cc.; distilled water, 181 Cc. Fol (GELATIN FIXATIVE). Dissolve 4 Gm. gelatin in 20 Cc. glacial acid on a water-bath, and to each 5 Cc. of solut. add 70 Cc. of 70-% alcohol, and i to 2 Cc. of 5-% aqueous chrome- alum solut. Fol (GLYCERIN JELLIES), i. Melt together one volume Beale's glycerin jelly and half to one volume of water, then add 2- to 5-% salicylic-acid solution, or carbolic acid or camphor. 2. Gelatin, 30 parts; water, 70 parts; glycerin, 100 parts; alcoholic solut. camphor, 5 parts. 3. Gelatin, 20 parts; water, 150 parts; glycerin, 100 parts; alcoholic solut. cam- phor, 15 parts. Fol (METAGELATIN VEHICLE). Metagelatin is prepared by adding a slight proportion of ammonia to a solut. of gelatin, and heating the solution for several hours. Coloring matters are then added as required, and the vehicles thinned if neces- sary by the addition of weak alcohol. After injection prepa- rations are thrown into strong alcohol or chromic-acid solu- tion to set the mass. Fol (NARCOTIZATION METHOD). Saturate the water containing the organisms with carbon dioxide gas. Fol (PICRO-CHROMIC ACID METHOD). Mix saturated aqueous solut. picric acid, 10 vols., with i-% chromic acid solut., 25 TESTS AND REAGENTS. 87 vols., and water 65 vols. At the moment of using add 0.005 vol. of osmic-acid solution, wash preparations with nearly boiling water, and then with alcohol. Fol (SLIDE-CLEANING SOLUTION). Dissolve potassium bichro- mate 3 parts, and sulphuric acid, 3 parts, in water 40 parts. Fonzes-Diacon (DIFFERENTIATING CREOSOTE AND GUAIACOL). i. Mix 10 Cc. of solut. (10 drops to liter) with 2 Cc. 1:200 copper-sulphate solut., then add i Cc. 1:250 solut. potassium cyanide orange-yellow to greenish-orange develops, accord- ing to quantity of guaiacol present. Color may be compared with that given by a solut. of known strength. 2. Dissolve trace of liquid in a little water, place on sheet of glass, add 2 to 3 Cc. 4-% solut. copper sulphate, then add 2 Cc. 1:250 solut. potassium cyanide striae form, emerald green with creosote; reddish gray with poor guaiacol; and purplish maroon with good guaiacol. Fordos (LEAD). Tin containing lead is stained yellow on apply- ing a drop of nitric acid, heating, then cooling and applying a drop 5-% potassium-iodide solut. Formanek (ALKALOIDS AND GLUCOSIDES). Add a little nitric acid to a small quantity of substance in a porcelain capsule, and evaporate slowly on water-bath, treat cooled residue with ammonia, then with caustic potassa. Various alkaloids and glucosides give different color-reactions and residues. For details of reactions with aloin, amygdalin, brucine, cotoin, paracotoin, emodin, narcotine, salicin, and strychnine, see MERCK'S REPORT, IV, p. 221. Formanek (INDICATOR). Alizarin Green B. Gives with alka- lies a green ; with acids a carmine-red. Forney (ALCOHOL IN ESSENTIAL OILS). See McClellan-Forney. Fourcroy (PHOSPHORIC ACID). A white crystalline ppt. is thrown down on adding to phosphoric acid ammonium chlo- ride and ammonia, followed by magnesium sulphate. Fraenkel (FIXING MIXTURE). Mix 15 parts i-% palladium- chloride solut. with 5 parts of 2-% osmic-acid solut. and a few drops acetic acid. Fraenkel (TUBERCLE STAIN). Boil aniline water in a test-tube, pour into watch-glass, add as many drops cone, alcoholic solut. fuchsine as will produce a shimmering color to surface. Then 88 TESTS AND REAGENTS. float cover-glass preparations on liquid for 5 to 10 minutes, then place in methylene-blue sulphuric-acid solut. for i to 2 minutes. Rinse in water or in 0.5-% acetic acid water. Fraenkel-Voge (CULTURE SOLUTION FOR BACTERIA). Sodium chloride, 5; neutral sodium phosphate, 2; ammonium lactate, 6; asparagin, 4; dissolved in distilled water, 1,000. Fraenzel (SUBLIMATE SOLUTION). Add i drop nitric acid to each Cc. 5-% aqueous sublimate solut. Fraenzel-Balmer (TUBERCLE BACILLI STAIN). See Balmer- Fraentzel. Francis (BILIARY ACIDS IN URINE). Dissolve 2 Gm. glucose (dried on water-bath) in 15 Gm. sulphuric acid, and overlay 4 Cc. of this reagent with 4 Cc. urine a purple color develops if biliary acids present. Francois (THEOBROMINE). i. o.i Gm. dissolved in i Cc. nitric acid and 2 Cc. water becomes cloudy on adding 10 Cc. io-% solut. silver nitrate, clears on warming, and crystallizes on again cooling. 2. Bromine water added to solut. of sub- stance in hydrochloric acid, and bromine excess driven off solut. turns blue on adding trace of ferrous sulphate in solut. and few drops ammonia. 3. Dark-green needles of theobromine tetraiodide form on adding iodine solut. to solut. of alkaloid in hydrochloric acid, collecting the ppt., dissolving it in io-% solut. potassium iodide, and crystallizing. Frankenstein (ANIMAL AND VEGETABLE FIBERS). When moistened with olive oil and then dried between filter-paper, animal fibers and cotton remain unaltered, whilst flax be- comes transparent. Frankland (NITROUS ACID). A faintly acid solut. of sulphanilic acid, and phenol. Reagent is mixed with the fluid to be tested, then ammonia is added if nitrous acid present, a red color appears. See Riegler's test. Franqui-Van de Vyvere (GLUCOSE). Reduction occurs on heat- ing urine containing glucose with a solution of bismuth hydrox- ide in potassium hydroxide. Fraude (ALKALOIDS). Boil a trace of alkaloid with several Cc. of an aqueous solut. perchloric acid, sp. gr. 1.13 to 1.14 aspidospermine is colored f uchsine-red ; brucine madeiro-red; strychnine reddish-yellow. TESTS AND REAGENTS. 89 Frebault (INDICATOR). Potassium- or sodium picramate (dinitramido-phenate) is changed from bright red to greenish- yellow by acids. Frederking (ALCOHOL IN ETHER). On shaking a mixture of ether and alcohol with an equal bulk of glycerin the volume of the latter will be increased. Freeborn (PICRO-NIGROSIN METHOD). Mix 5 Cc. of i-% aque- ous solut. nigrosin with 45 Cc. aqueous picric-acid solut. Stain for 3 to 5 minutes, wash with water, and mount in balsam. French (LEUCIN AND TYROSIN IN URINE). Ppt. urine with basic lead acetate; remove excess of latter with hydrogen sulphide, and evap. liquid to small volume on water- bath crystals of tyrosin form in 24 hours; leucin appears later. Fresenius (NITRITES). Add starch-paste, solut. potassium iodide, and sulphuric acid to liquid a blue color develops if nitrites present. Fresenius (NITROUS ACID IN WATER). The water to be examined is acidulated with acetic acid and distilled. The distillate is collected in potassium-iodide starch solution acidulated with sulphuric acid, whereby nitrous acid is in- dicated by the development of a blue color. Fresenius (PHENOL). If phenol is boiled with a solut. mercurous nitrate containing traces of free acid, metallic mercury is pre- cipitated, and the odor of salicylic aldehyde becomes apparent. See Plugge's phenol test. Fresenius-Babo (ARSENIC). Arsenates and arsenic sulphide are reduced on fusing with 12 parts of a mixture of sodium car- bonate, 3, and potassium cyanide, i, in a stream of carbonic acid, the substance being heated in a porcelain boat placed in a reduction tube. The arsenic may be identified by the formation of a mirror. Fresenius- Neubauer (PHOSPHORUS). Vapors of phosphorus reduce silver-nitrate solut. Freund (SULPHATES IN URINE). To 60 Cc. urine add 10 drops each i-% solut. alizarin and 5-% acetic acid. When mixture is orange, triturate with solut. barium acetate (11.22:1000) till ppt. distinctly red (i Cc. of barium-acetate solut. = 3 Mg. 90 TESTS AND REAGENTS. sulphur trioxide). If urine dark, decolorize with acetic acid and powd. zinc. Frey (AMMONIA CARMINE). Carmine, 0.15 to 0.30 Gm. ; ammonia, a sufficiency; water, 30 Gm. ; filter and add glyc- erin, 30 Gm., and strong alcohol, 8 to 12 Gm. Frey (ARTIFICIAL IODIZED SERUM). Distilled water, 135 Gm. ; egg albumin, 15 Gm. ; sodium chloride, 0.20 Gm. After filtra- tion add tincture iodine, 3 Gm. Any precipitate is removed by filtering through flannel, and a little iodine is then added to the filtrate. Frey (FUCHSINE SOLUTION). For staining microscopic prepa- rations, there is used a solut. of o.oi Gm. crystallized fuchsine, 20 to 25 drops absolute alcohol, and 15 Cc. of water. Friedenwald-Ehrlich (DiAzo REACTION FOR TYPHOID AND TUBERCULE). This is a modification of Ehrlich's reaction, in which the sulphanilic acid is replaced by /?-amido-acetophe- none. With this reagent the diazo reaction is obtained in Bacillus typhus abdominalis and B. tuberculosis miliaris. Friedlander (ACETIC GENTIAN-VIOLET). Cone, alcoholic solut. gentian violet, 50 Gm.; acetic acid, 10 Gm.; distilled water, 100 Gm. Friedlander (CAPSULE STAIN). Stain for 24 hours in Fried- lander's acetic-acid gentian- violet solut., then decolorize in o.i-% acetic- acid solut., and rinse in water. Friedlander (FIXING MIXTURE). Dissolve copper and zinc sulphates, 125 parts each, in i ,000 parts of water. Friedlander (STAINING METHODS). Cover-glass preparations are treated for 3 minutes with a i-% solut. acetic acid, and allowed to dry after removal of excess of liquid by filter-paper. Next place in gentian- violet aniline water (aniline water, 100 Cc.; concentrated alcoholic solut. gentian violet, n Cc.; absolute alcohol, 10 Cc.) for half a minute, wash in water, dry and mount in balsam. Sections are kept for 24 hours in a warm place, in the following solution: Cone, alcoholic solut. gentian violet, 50 Cc.; distilled water, 100 Cc.; glacial acetic acid, 10 Cc. Then treat for i or 2 minutes with o.i-% acetic acid, dehydrate, clear and mount in balsam. Friedlander (Wooo FIBER IN PAPER). Fuming hydrobromic acid colors wood fiber an intense green. TESTS AMD REAGENTS. 91 Frisch (CREOSOTE; PHENOL). An alcoholic solut. creosote is colored emerald green by an alcoholic solut. ferric chloride; phenol is colored blue. Fritsche (HYDROCARBONS). Dinitroanthraquinone yields crys- talline compounds with many hydrocarbons. Froehde (ALBUMIN). Solut. of molybdic acid in sulphuric acid gives a dark-blue color with albumin in substance. Froehde (ALKALOIDS). With alkaloids and glucosides a freshly prepared solution of o.oi Gm. of sodium molybdate in i Cc. of concentrated sulphuric acid (according to others o.oi Gm. : 10 Cc., also i Gm. : 10 Cc.) produces characteristic color- reactions. For details see Hager, Pharm. Praxis, 1886, I, 208. Proteins yield a dark-blue color. Froehde (HYDROCYANIC ACID). If a cyanide is fused with sodium thiosulphate, the mass dissolved in water and ferric chloride added, a blood-red color ensues. Frohn (ALBUMINOUS SUBSTANCES AND ALKALOIDS). Boil 1.5 Gm. freshly precipitated bismuth subnitrate with a solut. of 7 Gm. potassium iodide in 20 Cc. water, and then add 20 drops hydrochloric acid. The orange-yellow solution produces pre- cipitates in acid solutions of albumin and alkaloids. See also Dragendorffs test. Frommerherz (GLUCOSE). 41.76 Gm. of crystallized copper sulphate, 20.88 Gm. of potassium bitartrate, and 10.44 Gm. of potassa, dissolved in sufficient water to make a liter. See Fehling's test. Fuerbringer (ALBUMIN). Mixture of mercic and sodium chlo- rides with citric acid and sodium chloride. In albuminous urine the reagent causes a turbidity or a flocculent ppt. As, however, uric acid is also precipitated, the urine must first be diluted. See also Stuetz's albumin capsules. Fuerbringer (MERCURY). Urine is acidified and "brass-wool" immersed in it, then rinsed with water, absolute alcohol, and ether in turn. On heating the brass to redness in a combus- tion tube containing a little iodine at one end, mercury (if present) vaporizes and combines with the iodine to form red iodide. Fuge (REDUCED IRON). Dissolve 4 Gm. pure copper sulphate in 100 Cc. hot water, and add i Gm. of sample. Shake in a 92 TESTS AND REAGENTS. corked flask for 10 minutes, then filter, and titrate with deci- normal potassium-bichromate solution. Gabbet (DYE FOR TUBERCLE BACILLI). This consists of 2 Gm. methylene blue, 25 Gm. cone, sulphuric acid, and 75 Gm. water. Gabbet-Ernst (TUBERCLE STAIN). Stain cover-glass prepara- tion in cold Ziehl-Neelsen's carbol-fuchsine solut. for 2 to 5 min., then for i min. in Gabbet 's methylene-blue sulphuric- acid solut. (see above), and rinse in water. This method is one of the most rapid, convenient, and exact. Gaffky (STAINING METHODS). Leave sections hardened in alcohol for 20 to 24 hours in a deep-blue opaque solution, freshly made by adding saturated alcoholic solut. of methy- lene blue to distilled water. Then wash in distilled water, dehydrate in absolute alcohol, clear in turpentine oil, and mount in balsam. Gage (CLEARING MIXTURE). Mix 40 Cc. melted carbolic acid with 60 Cc. turpentine oil. Gage (DECALCIFICATION FLUID). Dilute a sat. aqueous solut. alum with an equal vol. of water, and to each 100 Cc. of the solution add 5 Cc. of strong nitric acid. Change every 2 or 3 days until decalcification complete. Gage (FORMALDEHYDE MIXTURE). Add two parts of 40-% formaldehyde solution to 1,000 parts normal salt-solution (o.7S-% in water). Gage (PICRIC ALCOHOL). Mix 250 parts of 95-% alcohol with 750 parts water and i part picric acid. Gage (PRESERVATIVE FLUID). Egg albumin, 15 Cc.; water, 200 Cc. ; mercuric chloride, 0.5 Gm.; sodium chloride, 4 Gm. Filter and preserve in a cool place. Gage (PRESERVATIVE FOR POTASH AND SODA PREPARATIONS). Mount tissues treated with strong potassa or soda solution, in 60- % potassium-acetate solut. (with or without the addition of i% acetic acid), or simply treat and mount in glycerin or glycerin jelly. They may be stained if the acetate be first washed out by treatment with alum solution for 24 hours. Gaglio (MERCURY VAPORS IN ATMOSPHERE). Pass air to be tested through a solut. palladium chloride in 500 parts of water. The palladium chloride is previously dissolved in TESTS AMD REAGENTS. 93 hydrochloric acid with aid of nitric acid and repeatedly evap- orated to dryness with hydrochloric acid. If mercury present the solution is reduced, as shown by the formation of black spots. Galippe (ALBUMIN). Picric acid solution is added drop by drop to the suspected urine. A white cloudiness indicates the presence of albumin. Compare Hager's alkaloid reagent. Gallois (INOSITE IN URINE). Free urine from glucose by fer- mentation and from albumin by boiling, evaporate to a small bulk, and add a drop mercurous-nitrate solut. If inosite present the residue upon complete evaporation is yellow, and, upon warming, becomes red. (By this treatment albumin is colored rose-red, sugar, black; hence these must previously be completely removed.) Ganassini (HYDROGEN SULPHIDE). The reagent is a solution of 1.25 Gm. ammonium molybdate in 50 Cc. distilled water, which is mixed with a separately prepared solut. of 2.5 Gm. of potassium sulphocynate in 45 Cc. water to which 5 Cc. cone. HC1 are added. Strips of filter-paper are impregnated with the solut. so obtained, and dried. The strips so prepared when brought into contact with H 2 S develop an intense, violet color. Should a red color develop in the solut. because of the presence of iron, it may be dissipated by adding a very small quantity of oxalic acid until the color becomes a yellow- ish-green. The solut. is then to be used as above stated. The reagent is stated to be advantageous because of its sensitive- ness, and because of the readiness with which it may be everywhere prepared. Gannal (MOUNTING MEDIUM). Dissolve i part of aluminium acetate in 10 parts water. Ganswindt (ROSE OIL). Impurities in rose oil may be detected by noting odor given off on atomizing a mixture of one drop oil and i fl. oz. water in a moderately warm room. Ganther (BLOOD STAINS). Place i drop of solut. of blood stain, or small portion of rust containing blood, on glass slide (on black paper), add i drop feebly alkaline water, and in a few minutes i drop hydrogen dioxide if trace of blood pres- ent, comparatively large bubbles of oxygen form, and unite to a froth persisting several hours, and collecting gradually 94 TESTS AND REAGENTS. towards the center. Pus behaves similarly. Test may be used to identify hemin crystals. Gantter (COTTONSEED OIL IN LARD). Dissolve i Gm. melted fat in 10 Cc. petroleum ether, add i drop cone, sulphuric acid, and shake mixture if cottonseed oil present, a dark-brown color develops ; pure lard remains colorless or a light brown. Gardiner (TANNIC ACID). Ammonium-molybdate solution pro- duces a yellow precipitate with the acid. Garrigou (ORGANIC MATTER IN MINERAL WATERS). Barium hydrate added to a mineral water ppts. all metallic oxides present and allows organic matters to be detected. For de- tails see MERCK'S REPORT, x, p. 87. Garrod (URIC ACID IN BLOOD). Add 0.5 Cc. acetic acid to 30 Cc. blood serum, and immerse a fine thread if uric acid pres- ent, crystals form on thread (obtained specially in gout but also in leucemia and chlorosis). Gassend (SESAME OIL). To 15 Cc. of the oil and 10 Cc. of oxalic-acid solution, add 2 to 3 Cc. of io-% sodium-bisulphite solut., shake, and set aside for 5 minutes if the red color permanent, the oil may be assumed to be adulterated with sesame oil. (Modified Baudouiri's test). Gatehouse (ARSENIC). A black stain is produced on silver-ni- trate paper held over mouth of test-tube in which an arsenical solution is heated with caustic soda and a strip of aluminium. Gaudail (ALBUMIN). Mercuric nitrate gives a ppt. with albumin. Gaule (FIXING LIQUID). Mercuric chloride, 5 Gm. ; sodium chloride, 0.5 Gm. ; water, 100 Cc. Gaultier de Claubry-Chatin (IODINE). See Chatin-Gaultier de Claubry. Gautier (ALBUMIN). 250 Cc. soda solution, 50 Cc. 3-% copper- sulphate solution, and 700 Cc. of glacial acetic acid. This mixture precipitates serum albumin from its solutions, but not egg albumin. Gautier (TANNIN REACTION). Precipitation effected by shak- ing with cuprous carbonate and adding alcohol, or by addition of aqueous copper-acetate (1:30). Gawalowski (ALBUMIN IN URINE). Improved Esbactis re- agent. Picric acid, i; citric acid, 2; water, 50; alcohol, 30; dissolve, and add water to 100. TESTS AND REAGENTS. 95 Gawalowski (ALCOHOL IN PERU BALSAM). Odor of aldehyde is given off on adding Peru balsam containing alcohol to a solut. of potassium bichromate in sulphuric acid. Gawalowski (BENZIN: BENZENE) . Picric acid is soluble in the benzene, giving an intense yellow color; insoluble in benzin. Gawalowski (INDICATOR). Methyl-orange and phenolphtalein solution, used as a neutrality indicator. Gives with alkalies a red color; neutral solutions give a lemon-yellow; and acids give a pink color. Gayard (MANGANESE IN ZINC). On treating with dil. sulphuric acid and electrolyzing clear solution, a violet color appears around platinum electrode. Gayard (TANNIN; GALLIC ACID). To distinguish tannin from gallic acid, add a cone, solution lead acetate the tannate formed is insoluble ; the gallate is said to be soluble. Gayon-Ganon-Molher (ALDEHYDES). Test solution is prepared by mixing 100 Cc. sodium-bisulphite solut. sp. gr. 1.3, with 150 Cc. i : i, ooo aqueous fuchsine solution, diluting with i liter water, and finally adding 15 Cc. cone, sulphuric acid. Gene (PERU BALSAM). Shake 5 Gm. Peru balsam with 5 Gm. sodium-hydroxide solut. (sp. gr. 1.168 to 1.172), then wash out with three successive 10 Gm. of ether. Evaporate solvent in tared dish until two weighings at 5 minutes' interval show difference of not more than i Cgm. To weighed residue add 35 to 40 Cc. of semi-normal alcoholic potassa solution and 20 Cc. alcohol, saponify on water-bath, and titrate with acid. Weight of residue (cinnamein) should be from 57 to 60%; and the acid number between 235 and 238. Geissler (ALBUMIN). A white ppt. is given by urine containing albumin on adding solut. potassium iodide, 3.32 Gm., and mercuric chloride, 1.35 Gm., in water, 40 Cc., and acetic acid, 20 Cc. Geissler (ALBUMIN TEST-PAPERS). Strips of filter-paper, some saturated with cone, citric-acid solution, some with 3-% corrosive-sublimate solut. to which 12 to 15% potassium iodide has been added. A strip of the acid paper is dipped into the urine, then the mercury-potassium-iodide paper if 96 TESTS AND REAGENTS. albumin present a ppt. forms. Concentrated urine must first be diluted. See Oliver's test. Geissler (FUCHSINE IN WINE), i. Amyl alcohol shaken with wine, after adding excess of ammonia, takes up fuchsine only. 2. Melted stearin is poured into wine heated to 60 C., and the mixture shaken briskly. On slowly cooling the stearin will be colored red if fuchsine present. Geitel (NEUTRAL FAT IN FREE FATTY ACIDS). Dissolve 2 Gm. of the fatty acids in 15 Cc. hot alcohol and add 15 Cc. ammonia if considerable neutral fat present, solution be- comes turbid. Traces of neutral fat detected by overlaying solution with cold methyl alcohol if neutral fat present a turbidity occurs at contact-point. Geith (STEARIN IN WAX). Wax containing stearin causes lime-water to lose its alkalinity on boiling. Genfer (STAIN FOR MICRO SECTIONS). A i-% ammonio-congo- red solut., to which is added 0.1% of chrysoidine. The section is first bleached with Javelle water, then well washed and made alkaline with ammonia, before immersion in stain. In vegetable preparations, the cuticle is stained golden-yellow; wood fibers orange-red to straw-yellow; phloem rose-red. Preparations should be mounted in glyc- erin-gelatin; the colors are permanent. Gentele (SUGAR DETERMINATION). Potassium ferricyande, 27.45 Gm.; solution caustic soda, sp. gr. 1.34, 25 Cc., water to make 250 Cc. Geoffroy (MOUNTING MEDIUM). Dissolve with as little heat as possible, 3 to 4 Gm. gelatin in 100 Cc. of io-% aque- ous chloral-hydrate solut. See Gilson's chloral-hydrate jelly. Geogehan (Acio TEST). All inorganic and organic acids, ex- cepting hydrocyanic acid, precipitate red mercuric iodide from a solution of a double salt of mercury cyanide and potassium iodide. Gerard (BILIARY PIGMENTS). Dilute aqueous iodopotassium- iodide solut. is added in small quantity to chloroformic extract of urine, and potassa solut. added reddish color of the chloroformic extract disappears, and, if biliary pigments present, potassa solut. is colored green. TESTS 4ND REAGENTS. 97 Gerber (FIXED OILS IN COPAIBA). Pure copaiba remains clear on shaking with ammonia; fixed oils, if present, cause cloudi- ness. Gerhardt (ACETONE IN URINE). Treat 10 to 15 Cc. urine with ferric-chloride solut. until a ppt. is formed. Filter, and again add ferric chloride to nitrate. If acetone present a Bordeaux- red color develops. Gerhardt (BILIARY PIGMENTS), i. A green color forms on extracting urine with chloroform, decanting, and mixing with ozonized turpentine oil and a little dilute potassa solut. 2. A yellow to brownish-yellow color, with greenish fluorescence, forms on adding iodine and sufficient dilute potassa solut. to chloroformic extract. Gerhardt (BRUCINE). A violet color develops on dissolving brucine in nitric acid, heating solut. till it becomes yellow, then adding water and a solut. stannous chloride. Gerrard (ATROPINE AND HYOSCYAMINE). Solut. 5 Gm. mercuric chloride in 95 Gm. 50-% alcohol. If 2 Cc. of reagent are warmed with o.ooi Gm. atropine, a red ppt. forms. Hyo- cyamine produces a similar ppt. Homatropine is not pptd. Gerrard (GLUCOSE). Dilute 10 Cc. Fehling's reagent with 40 Cc. of water and heat to boiling; a solut. of potassium cyanide of about 5-% strength is then run in until the blue color is only just visible. Another 10 Cc. of Fehling's solution are now added, and the urine or other saccharine solution run in rapidly from a burette, the liquid being kept boiling; when the color is discharged the volume of liquid added is read off; this volume contains 0.05 Gm. of glucose; in cases where more than 0.5% of glucose is present, the urine must be diluted with water. Giacomi (STAINING METHOD). Stain cover-glass preparations for a few minutes in hot solut. fuchsine, then place in water containing a few drops ferric- chloride solut., and afterwards decolorize in strong ferric-chloride solution. If any ppt. be formed with the iron solution, complete decolorization in alcohol. Counter- stain with vesuvine. Giacomi (SYPHILIS-BACILLUS STAIN). Stain several minutes in aniline- water fuchsine, then place in water containing 98 TESTS AND REAGENTS. several drops Fe 2 Cl 6 solut., and finally rinse in water. Syph- ilis bacilli lose their color in mineral acids at once, or very quickly 35 to 45 seconds (differentiation from tubercle and leprosy bacilli) but they bear immersion in alcohol for a considerably longer time without effect (differentiation from smegma bacillus). Gibbes (BORAX CARMINE). Carmine, 30 grains; borax, 120 grains; water, 4 fl. oz. Decant when clear. After staining sections in this for a few minutes, wash in mixture of hydro- chloric acid, i part, and absolute alcohol, 20 parts. When tissues are bright rose-red wash in several changes of alcohol to remove acid. Gibbes (DOUBLE STAINING METHOD). Magenta, 2 Gm.; me- thylene blue, i Gm.; add slowly aniline, 3 Cc., dissolved in alcohol, 15 Cc. Subsequently add 15 Cc. distilled water and keep stain in a stoppered bottle. Place cover-glass preparations for 4 minutes in the slightly heated stain and leave sections for some hours in the stain at ordinary tempera- ture. Afterwards wash in methylated spirit until no more color comes away, then dehydrate, clear in cedar oil, and mount in balsam. Gibbes (MAGENTA STAIN). Magenta, 2 Gm.; aniline, 3 Gm.; rectified spirit, 20 Cc. ; distilled water, 20 Cc. Gibbs (STAIN FOR TUBERCLE BACILLI). Fuchsine, 2, and methylene blue, i, are well rubbed together with a mixture of aniline, 3 vol.; alcohol (95-%), 15 vol.; water, 15 vol. Prep- arations stained with this solut. show tubercle bacilli red, on a blue ground. Giesbrecht (SHELLAC FIXATIVE). Filter a moderately strong solut. of brown shellac in absolute alcohol and spread on warmed slides by means of a glass rod dipped in the solut. and drawn once over each slide. Then let the slides dry. Brush them over with creosote shortly before applying sections, and after the latter have been arranged, heat on a water-bath for about 15 minutes at the melting-point of the paraffin. On cooling, the sections will be found to be firmly fixed in the shellac, and the paraffin may be dissolved away by dropping turpentine on them. TESTS AND REAGENTS. 99 Giesecke (FREE SULPHURIC ACID IN ALUMINIUM SULPHATE). Tincture of hematoxylon causes in dilute solut. of acid-free salt a deep, violet color; if free acid present, color will be pale, brownish-yellow. Giesel (COCAINE). 5 Cc. i-% cocaine solut. yield upon addition of 2 Cc. sat. potassium-permanganate solut. a violet ppt. of cocaine permanganate. Gieson, Van- (FORMALIN METHOD). Tissues are hardened in 4-, 6-, or io-% solutions of formaldehyde, followed by 95-% alcohol. Gigli (PHENACETIN). Mix equal volumes saturated solut. phenacetin and chlorine water, and add few drops ammonia a reddish to brown color develops. If phenacetin contains 5 to 10% quinine, a handsome blue develops on adding chlo- rine water. Gil (FREE SULPHUR). Heat alcohol containing a small quan- tity of caustic potassa or caustic soda with substance to be examined if sulphur present, the alcohol will acquire a blue or green color, according to quantity of sulphur present. Gilbert (MAGNESIA MIXTURE). Magnesium chloride, 10.15 Gm.; ammonium chloride, 20 Gm.; io-% ammonia, 40 Cc.; water, to make 100 Cc.; 10 Cc. of this solut. ppt. 0.355 Gm. phosphoric acid. Gilbert (PHOSPHORIC ACID). Magnesia mixture is used as a reagent. Gilson (BLEACHING PROCESS). Objects hardened in bichromate solution are bleached with a few drops alcoholic solut. of sul- phurous anhydride. Gilson (CHLORAL-HYDRATE JELLY). Mix equal volumes melted gelatin and glycerin, and add crystals of chloral hydrate until the bulk of the mixture has increased by one half, warming until dissolved. See Geoffrey's mounting medium. Gilson (HARDENING MIXTURE). Mix i part chloroform with i or 2 parts oil cedar, and add from time to time more oil cedar, until all the chloroform is replaced. Gilson (IMBEDDING PROCESS). Dehydrate objects, soak in ether, and place in test-tube containing collodion or thin celloidin solution. Dip the tube into a bath of melted paraffin loo TESTS AND REAGENTS. and allow collodion to boil until it becomes syrupy, and is reduced to about one-third its original volume. Then turn out the mass, mount on a block of hardened celloidin, and harden in chloroform for about an hour. Next clear in cedar oil and fix on the microtome. Gilson (MERCURO-NITRIC MIXTURE). Nitric acid (sp. gr. 1.45 6) t 78 Cc.; glacial acetic acid, 22 Cc.; mercuric chloride, 95 to 100 Gm.; alcohol (6o-%), 500 Cc.; distilled water, 4400 Cc. When required for marine animals, add a few crystals iodine. Any granular precipitate in the preparations should be re- moved by washing with water containing a little tincture of iodine. Gilson (PRESERVATIVE FLUID). Alcohol (6o-%), 60 Cc.; water, 30 Cc.; glycerin, 30 Cc.; acetic acid (15 parts glacial acid, 85 water), 2 Cc.; mercuric chloride, 0.15 Gm. Girard (COAL-TAR DYES IN WINE). To 20 Cc. wine add 4 Cc. io-% potassa solut. and 20 Cc. 5-% mercurous-sulphate solut., shake and filter natural wine yields a colorless filtrate; arti- ficially colored wine a red. Girardin (SULPHUROUS ACID). Hydrochloric acid containing sulphurous acid gives a yellowish-brown ppt. on adding to 16 Gm. of the acid 10 Gm. crystallized stannous chloride and 2 to 3 Cc. water. Glaessner (DIFFERENTIATING FATTY OILS). Test depends upon their behavior toward fuming nitric acid, concentrated sulphuric acid, and carbon disulphide. For details consult Benedikt; "Analyse der Fette" II, p. 309. Glage (PRESERVATIVE SOLUTION FOR ANATOMICAL SPECIMENS). Modified Keiserling's method. Potass, nitrate, 10 Gm.; potass, acetate, 30 Gm.; formaldehyde, 750 Gm.; dist. water, i ,000 Gm. In this soak for one or two days sections 1.5 centimeters thick, then transfer them to 8o-% alcohol, in which they resume their natural color. They may then be preserved in a mixture of water, glycerin and potassium acetate. Glenard (QUININE). On adding a drop of ammonium-sulphate, phosphate, or oxalate solution, quinine separates in needle- shaped crystals, as seen under the microscope. Cinchonine is amorphous. TESTS AND REAGENTS. 101 Gmelin (BILIARY MATTER). Pour cautiously down the side of a conical glass vessel containing 6 to 8 volumes of urine 2 vol- umes of a mixture of equal parts of 25-% nitric acid and red fuming nitric acid, so that the acid may collect at the bottom of the vessel. If biliary pigments present zone color reactions are produced, changing from green to blue, violet, red, and yellow. To increase intensity of reaction, a ppt. of barium sulphate is produced in the urine which carries with it the coloring matter. The collected and dried ppt. is then tested with nitric acid. Brueck's modification: Addition first of diluted, boiled nitric acid, then concentrated sulphuric acid. Dragendorff's, or Deubner's modification: Filter through a porous plate instead of filter-paper and then test residue on the plate with nitric acid. Heintz's modification: Bring urine and fuming nitric acid in contact on porcelain plate, or overlay in test-tube play of colors takes place, passing from green to blue and finally violet. Hilger's modification: The urine is treated with barium hydrate at a moderate temperature and the resultant ppt. .after washing is tested with nitric acid. Vitali's modification: A few drops of potassium-nitrite solution are added, then diluted sulphuric acid. Masse? s modification: Cone, sulphuric acid is first added to urine, then a crystal of potassium nitrite green streaks radiate from the fragments of the nitrite. Fleischl's modification: The urine is mixed with an equal volume of cone, sodium-nitrite solution, then a layer of cone, sulphuric acid is added from below by means of a pipette. Rosenbach's modification: Nitroso-nitric acid is added to residue left on filtering the urine. 'Gmelin-Smithson (MERCURY). Envelop one end of a thick pol- ished iron wire with gold leaf, and immerse it in the fluid to more than cover the gold part. If mercury present, the gold soon becomes white. The wire bearing the gold is then dried over sulphuric acid, cut off, and heated to redness in a glass tube drawn out to a point, in a current of hydrogen, when the mercury condenses in the cool part of the tube. 102 TESTS AND REAGENTS. Goadby (PRESERVATIVE FLUID). 120 Gm. sodium chloride, 60 Gm. of alum, 0.25 Gm. mercuric chloride, and 2.33 liters water. A stronger preparation contains only half the quan- tity mercuric chloride and water. When preparations con- tain calcium carbonate, omit the alum. Godbay (SOLUTION). See Goadby' s preservative fluid. Godeffroy (ALKALOIDS), i. Solution antimony chloride pre- cipitates from hydrochloric-acid solutions, aconitine, atropine, quinine, cinchonine, piperin, strychnine, and veratine, as white or yellow ppts. Caffeine and morphine are not pptd. 2. In addition to antimony chloride and silico-tungstic acid, Godeffroy recommended, as reagents for alkaloids, solutions of ferric chloride or stannous chloride in hydro- chloric acid. For cinchona alkaloids he applied the micro- sulpho-cyanide test. See Proceedings Am. Pharm. Assoc., 1877-78. Godeffroy-Laubenheimer (ALKALOIDS). Silico-tungstic acid pro- duces very difficultly soluble precipitates with solutions of hydrochlorates of alkaloids. Goette (HARDENING FLUID). 50 Cc. of 2-% copper-sulphate solution; 50 Cc. 25-% alcohol; and 35 drops rectified wood vinegar. Golding-Bird (ALDEHYDE). Spirit nitrous ether contain- ing aldehyde is colored yellow on adding dilute potassa solut. Goldmann (HEROIN). Boil small quantity of substance with dil. sulphuric acid, add some alcohol, and boil again odor of acetic ether developed if heroin present. Goldmann (SALOPHEN). Boil substance with 2-% soda lye a blue color, due to atmospheric oxidation, develops. Goldmann-Baumann (CYSTINE). See Baumann-Goldmann. Golgi (SUBLIMATE METHOD). Harden small cubes of tissue for 15 to 30 days in Muller's fluid, which should be frequently changed. Then transfer for 8 to 10 days to 0.25- to i-% aqueous mercuric-chloride solut., which must be changed, as it becomes colored. If desired, treat subsequently with weak sodium-sulphide solution to darken stain and make it sharper. After cutting sections from material thus prepared they must be well washed with water. TESTS 4ND REAGENTS. 103 Gorup-Besanez (CREOSOTE). An emerald-green color develops on adding alcoholic ferric-chloride solut. to creosote; carbolic acid gives a blue. Gorup-Besanez (PEPTONE). This is the biuret reaction, a pale rose-red being produced on adding a little potassa- or soda solution, together with a few drops of very dilute solut. (almost colorless) of copper sulphate. Albumin gives a blue color; albuminates, a violet. Gottstein (BACTERIA IN POTABLE WATER). Bacteria causes evolution of oxygen when hydrogen dioxide is added to water containing them. With 10,000 in i Cc. disengagement is very brisk; with 1,000 in i Cc. evolution still distinct. Reaction does not sometimes take place until 15 minutes after adding the dioxide. Gouver (ALBUMIN). A solut. of mercuric cyanide in excess of potassium iodide gives with albuminoids a white ppt. Graham- Hoffmann (ALKALOIDS). Take up alkaloids with animal charcoal, then extract with suitable solvents. Grahe (CINCHONA BARKS). Genuine cinchona barks when heated in a test-tube yield red fumes; spurious barks yield vapors and a brownish tar. Gram (BACTERIA STAIN), i. Shake 15 drops aniline oil with 15 Gm. water, filter the solut. and add to filtrate 4 to 5 drops of sat. alcoholic solut. gentian violet. 2. Shake 3.3 Cc. aniline with 100 Cc. distilled water, filter, add n Cc. cone, alcoholic solut. gentian violet and 10 Cc. absolute alcohol. After preparations have been stained for i to 3 minutes in one of the above they are quickly rinsed in absolute alcohol and then placed in Gram's solut. of iodine in potassium iodide (iodine, i Gm.; potassium iodide, 2 Gm. ; water, 300 Cc.), until they have acquired a brown color. This takes about i to 3 minutes, and they are next washed in 90-% alcohol until pale yellow, then dehydrated, cleared, and mounted in bal- sam. Counterstain with eosine or vesuvine if desired. Cer- tain bacteria (anthrax) retain the color, whereas others (cholera, typhus, Bact. coli), as well as cellular nuclei, are decolorized. Gram (IODINE SOLUTION). Iodine, i Gm. ; potassium iodide, 2 Gm.; distilled water, 300 Gm. 104 TESTS AND REAGENTS. Gram-Gun ther (MICRO-SECTION STAIN). A modification of Gram's process, in which the section, after treatment with iodine, is put into absolute alcohol for half a minute, then in 3-% hydrochloric acid-alcohol for ten seconds, and again for a few minutes in absolute alcohol, this treatment being con- tinued till no more decoloration takes place. Finally the sec- tions are placed in xylene, then in Canada balsam. Grandeau (ALKALOIDS). To the solution of alkaloids in cone, sulphuric acid, bromine water is carefully added. With some alkaloids it produces characteristic color reactions. The solu- , tion of digitalin and digit alein in sulphuric acid is yellow, but changes to rose-red and violet by the action of bromine. Preparations of digitalis yield the same reaction. Morphine also produces a red color. Grange (IODINE). A violet or blue color is developed with hyponitrous acid, chloroform, and starch paste. Grant-Cohen (ALKALIES WITH THE SULPHITES). Place in a flask a measured volume of hydrogen dioxide colored with methyl orange, and made exactly neutral with sufficient caus- tic soda, then add solut. containing a known quantity of salt to be analyzed, and boil. Sulphites are oxidized to sulphates; when cool, more methyl orange is added, and the liquid titrated with normal acid. Graser (STAINING METHOD). Stain sections for 12 to 24 hours in an extremely dilute aqueous solut. methyl violet, then wash out in acidulated alcohol, and subsequently in pure alcohol. Grassini (COBALT). On adding solut. potass, sulphocyanate to a dil. solut. cobalt chloride and overlaying with alcohol the latter acquires a turquoise blue on rotating. H 2 O 2 com- pletely destroys the color. Gravis (AGAR AGAR). Agar agar, i part; water, 1,000 parts. Used for fixing serial sections on slides. Use like Born- Wieger's quince mucilage, which see. Gray (GELATIN PROCESS). Fix serial sections on slides with a solut. of gelatin, i part, in water, 100 parts. Let slides dry spontaneously overnight , then remove paraffin with a suitable solvent, and treat preparations for 5 minutes with a 2-% I solut. potassium bichromate to render the gelatin insoluble. Stain as desired, and mount. TESTS AND REAGENTS. 105 Greenwalt (TEST-PAPER). Iris Paper. Paper impregnated with a hot aqueous extract of Blue flag, and dried. The paper, when neutral, has a blue color, changed to green by alkalies, and to red by acids. Grehant (CRUCIFEROUS OILS). The fixed oils of the Cruciferae yield a black color on boiling with potassa lye and adding silver-nitrate solut. Greittherr (COCAINE REACTION). A few drops cocaine solu- tion mixed with 2 to 3 Cc. chlorine water and a few drops 0.5-% palladium-chloride solut. yield a handsome red ppt., insoluble in alcohol, and in ether, but soluble in sodium- thiosulphate solution. Grenacher (ALCOHOLIC CARMINE). Add 3 to 4 drops hydro- chloric acid, and a few grains powdered carmine to 50 Cc. 60- to 80- % alcohol. Boil for 10 minutes, cool, and filter. Grenacher (ALUM CARMINE). Dissolve 5 Gm. ammonia alum in 100 Cc. distilled water; add i Gm. carmine, and boil for 20 minutes; filter when cool, and add distilled water to make up to 100 Cc. Grenacher (BLEACHING MIXTURE). Glycerin, i part; 80- % alcohol, 2 parts; add 2 to 3% hydrochloric acid. Grenacher (BORAX CARMINE). Aqueous: Borax, i to 2; car- mine, 0.5 to 0.75. Boil with water, 100 fl. parts, then add acetic acid carefully to purple solut. till color deep-red. Filter after 124 hrs. Alcoholic: Carmine, 2 to 3; borax, 4. Dissolve in boiling water, 100 fl. parts, then dilute with equal vol. of 70-% alcohol, and filter after standing some time. Pieces of tissue are stained in this for i to 3 days, then trans- ferred to 70-% alcohol containing 0.5 to i% HC1. Grenacher (HEMATOXYLIN STAIN). Mix 4 Cc. saturated solut. hematoxylin crystals in absolute alcohol and 150 Cc. sat- urated aqueous solut. ammonium alum. After solution has stood in the light a week it is filtered, and glycerin, 22 Cc., and methyl alcohol, 25 Cc., added. See also Dela- field's hematoxylin. Grenacher (HYDROCHLORIC-ACID CARMINE). As much carmine as will lie on the point of a knife is dissolved in 50 Cc. 60- to 80- % alcohol, to which are added 3 to 4 drops hydrochloric acid. Then filter. 106 TESTS AND REAGENTS. Grenacher (STAINING SOLUTION FOR CELL NUCLEUS). Car- mine, 0.5 to i; potassium or ammonium alum, i to 5; water, 100 fl. parts. After filtering, add a trace of carbolic acid. Greshoff (!ODOFORM). lodoform reacts actively with silver nitrate, yielding carbon monoxide, silver iodide, and nitric acid. Griess (FECAL MATTER IN WATER). A i-% solut. of diazo- sulphanilic acid made alkaline with soda solution. Water containing fecal matter becomes yellow within five minutes on addition of this solution. Griess (NITROUS ACID), i. A solution of a salt of meta- phenylenediamine produces a yellowish-brown color with nitrous acid. A 0.5-% solut. of the base is prepared with the aid of sufficient sulphuric acid to acid reaction. If the solut. is not colorless it should be decolorized with freshly-burnt animal charcoal. 2. A solut. of sulphanilic acid and naph- tylamine sulphate is colored red by traces of nitrous acid. The solution to be tested is acidified with sulphuric acid; sul- phanilic acid solution is added, and, after a few minutes, solution of naphtylamine sulphate, which has been decolor- ized with animal charcoal. See Lunge's reaction. Griess (TEST-PAPER FOR NITRATES AND NITRITES), i. Paper impregnated with an alcoh. solut. sulphanilic acid and alpha-naphtylamine sulphate (or hydrochlorate). Gives with nitrous acid and nitrites a red color. Also used to detect bilirubin and aldehydes in urine. 2. Metaphe- nylenediamine paper. Gives a yellowish-brown color with nitrites. Griess-Ilosvay (NITROUS ACID). Dissolve sulphanilic acid, 0.5 Gm., in acetic acid, 150 Cc., then add naphtylamine, o.i Gm., boiled with water, 20 Cc. The colorless solution is poured off from the blue- violet residue, and acetic acid, 150 Cc., added to it. The solutions are then mixed and, if necessary, rendered colorless by shaking with zinc dust. The reagent should be kept in well-closed vessels. Griessmayer (FREE ALKALIES). The colorless mixture ob- tained on adding i Cc. centinormal iodine solution to one drop of tannin solution becomes a brilliant red on adding a faintly alkaline solution. TESTS AND REAGENTS. 107 Griessmayer (TANNIN), i. The author's test for free alkalies is reversed, the same red color being developed. 2. Starch solution colored blue with a very dilute iodine solution (i : 100,- ooo) is decolorized on adding tannin solut. ; potassium nitrate restores the color. Grigg (ALBUMIN). Metaphosphoric acid precipitates albumin. See Berzelius' albumin reagent. Griggi (AciDS [MINERAL] IN VINEGAR). Add i drop of 25-% fuchsine solut. (in 90-% alcohol) to i Cc. vinegar if pure, no change of color; if mineral acids present (even i%), color becomes a dirty-yellow. Griggi (BENZOIC ACID IN BENZONAPHTOL). Exhaust sub- stance with alcohol, and treat extract with potassium iodide and potassium iodate iodine separates if free benzoic acid present, and is shown by yellow color of liquid, or by reddish- violet color of carbon disulphide on admixture of latter. Avoid an excess of potassium iodide. Griggi (DIFFERENTIATING GALLIC ACID FROM TANNIN AND PYROGALLOL). Shake a few Cc. of i-% solut. of substance with i Cc. of 3.3-% solut. potassium cyanide bright ruby-red color develops with gallic acid. Tannin or pyrogallol simi- larly treated gives a yellowish-red. With excess of reagent gallic acid gives permanent yellowish-brown ppt.; tannin a characteristic dirty-white ppt. Griggi (DIFFERENTIATING IRON CITRATE AND POTASSIO-FERRIC TARTRATE). Dissolve a few scales in 5 Cc. water, with warmth if necessary, and add 5 Cc. 5-% solut. sod. salicylate with iron citrate, solut. is at once dark-red; potassio-ferric tartrate remains uncolored, or darkens only after a while. Griggi (IRON IN COPPER SULPHATE). Overlay 5 Cc. of 1:5 copper-sulphate solut. with 5 Cc. ethereal io-% solut. salicylic acid more or less violet zone forms if iron present. Grimaux (NITRATES). An aqueous solut. of nitroquinetol, acidulated with sulphuric acid, gives with nitric acid or nitrates an immediate ppt. of nitroquinetol nitrate. Grimshaw (ACETIC ACID IN CALCIUM ACETATE). Treat 10 Gm. acetate with water, add excess of sodium bisulphate, filter, make up to definite volume, and titrate a known vol- ume with standard alkali. Evaporate an equal volume to io8 TESTS AND REAGENTS. dryness with repeated moistening with water to drive off free acetic acid, dissolve residue, and titrate with alkali difference between two titrations gives quantity of acetic acid. Grismer (GLUCOSE IN URINE), a. Solut. safranine 1:1,000. b. Solut. potassium hydrate. Boil i Cc. urine with 5 Cc. a and 2 Cc. b decolorization denotes glucose. Grocco (CREATININE IN URINE). Modified Neubauer's method. Urine acidified with acetic acid is kept for 24 hours then treated with milk-of-lime until only faintly acid; calcium chloride is then added, and the liquid evaporated, keeping it faintly acid by cautious addition of acetic acid. The residue is then extracted with alcohol containing a little sodium acetate, and the filtered liquid pptd. with alcoholic zinc chloride. Grodyki (ACETAL). lodoform is formed on adding to a dilute solution a few drops hydrochloric acid, followed by soda solution and iodine. Grove (MORPHINE). A dark-brown color is produced by mor- phine on adding a few drops sulphuric acid, heating moder- ately, and adding a trace of potassium perchlorate entirely free from chlorate. Gruber-Widal (REACTION). See Widal reaction. Gruenhut (GLYCERIN). Mix substance with double its weight potassium bisulphate, heat on sand-bath until frothing com- mences, and collect distillate in cooled receiver. Condensate will smell strongly of acroleine, and will reduce alkaline silver solution in the cold. Guareschi (CARBOLIC ACID). A purplish-red color develops on evaporating to dryness with potassa and mixing warm residue with chloroform. Guenzburg (FREE HYDROCHLORIC ACID IN GASTRIC JUICE). Dissolve 2 Gm. phloroglucin and i Gm. vanillin in 30 Gm. alcohol. If a few drops of solution be evaporated with an equal bulk gastric juice in a porcelain capsule, the presence of hydrochloric acid is indicated by the formation of a red film. Guenzburg (TEST-PAPER FOR HYDROCHLORIC ACID). Paper impregnated with an alcoholic solution of phloroglucin- vanil- lin (2:1) gives a red color with HC1. TESTS AND REAGENTS. 109 Guerin (ALBUMIN IN URINE). Add a io-% solut. chromic acid to 5 or 6 Cc. urine a ppt. or turbidity not dissipated by heat indicates albumin. Peptones and protopep tones (hemialbumose ; albuminose) and some alkaloids also give ppts., but these disappear on heating. Guerin (ALBUMINOIDS IN URINE). Add 10 to 15 drops of io-% solut. sozoiodolic acid to 8 or 10 Cc. of urine a flocculent ppt. or cloudiness forms, according to quantity of albumin present. Alkaline urates and uric acid not pptd. by reagent. Albumoses, peptones, and most alkaloids pptd. by the acid, but ppts. disappear on heating. Nucleo-albumins cause only faint cloudiness in cold, and an insol. ppt. on heating. Guezda (ALBUMINS). Solution of nickel sulphate and ammo- nia gives a ppt. with albumins. Guezda (!NDOL BASES AND ALBUMINOIDS). Fuse trace of indol with 0.5 Gm. oxalic acid a purple-red melted mass or sublimate, scarcely changed by KOH, is obtained. Alpha- methylindol, skatol, and methylindolcarbonic acid also give the purplish-red color; alphaphenylindol affords a greenish- yellow sublimate, changing to black. Oxalic acid fused with albumin, peptone, and gelatin affords a pink sublimate. Other animal substances behave differently, some giving a greenish, some only very little characteristic color reactions. Alloxanthin, however, gives with oxalic acid a red color. Guibourt (ROSE OIL), i. Impure oil is colored brown when exposed under a bell- jar with iodine. 2. An apple-green color with nitrous-acid vapors indicates rose-geranium oil. 3. Sulphuric acid does not destroy odor of pure rose oil. Guignet (REAGENT). Ammoniacal solution of copper sulphate. Guldens tee den (COPPER IN WATER). Acidulate 250 Cc. water with acetic acid, pass hydrogen sulphide into solut., and add 0.5 Gm. talcum (purified by boiling with nitric acid). Shake, let settle, and decant. Collect ppt. and wash it with a few Cc. warm nitric acid. Evaporate washings to dryness, and dissolve residue in few drops water. Place a drop of this solut. on a polished iron surface with a trace HC1. To another portion add a drop pqtassium-chromate solut. with acetic acid, then add i or 2 drops ammonia and a trace of phenol a blue color develops in a few hours. TESTS AND REAGENTS. Gulielmo (ATROPINE). On heating with cone, sulphuric acid an odor of orange flowers (some say rose) develops. Gulli (OiL TURPENTINE IN BERGAMOT OIL). Mix several grammes suspected oil with alcoholic potassa solut., and evaporate to dryness in a platinum dish. Ignite residue, treat with dist. water, filter, and test solut. for HC1 (which will be present if the bergamot oil contains any oil turpentine sat- urated with HC1, and which is used as an adulterant). Gunn (CocA ASSAY). Dampen 5 Gm. powd. coca with 2-% ammonia, let stand 30 minutes, then percolate with ammo- niated ether to obtain 100 Cc. percolate (or until exhausted). Shake out percolate with 3 washings of 2-% HC1, then wash acid extract once with ether, make alkaline with ammonia, wash out thrice with ether, collect ethereal washings in a tared dish, evaporate solvent, and dry residue at 75 C. Gunning (ACETONE). lodoform and a black precipitate of nitrogen iodide are formed on adding tincture of iodine and ammonia to the solution to be tested (e. g., distillate from urine). The nitrogen iodide gradually disappears, and the yellow color of the iodoform predominates. Alcohol in this case does not produce iodoform. Compare Lieben's reaction. Gunther (BACTERIA STAIN). Modified Gram's method. Stain in aniline- water gentian- violet i minute, dry with filter-paper, treat with KI solut. 2 minutes, then with alcohol 30 seconds, 3-% HC1 10 seconds, then with alcohol and with cedar oil, and finally mount in Canada balsam. Gutzeit (ARSENIC). The substance to be tested, together with pure zinc and pure dilute sulphuric acid, is placed in a test- tube, the mouth of which is closed with a piece of filter-paper moistened with a few drops of 50-% silver-nitrate solut. The arseniuretted hydrogen formed if arsenic present produces a yellow spot on the paper, which is blackened upon moistening with water. See Flueckiger's test for arsenic. Guyard (MANGANESE IN ZINC). See Gayard. Guyard (TANNIN: GALLIC ACID). See Gayard. Guyon (ALDEHYDES). Dissolve i Gm. fuchsine in i liter water and add a mixture of 20 Cc. sodium-bisulphite solut. (30 Be.) and 10 Cc. concentrated hydrochloric acid, i Cc. of reagent added to 2 Cc. of solution to be tested will show the TESTS AND REAGENTS. in presence of aldehyde by formation of an intensely purple-red color. Reagent also known as Schiffs reagent. Guyot (AMMONIA). Potassium bromide is added to an acid solution of mercuric nitrate until the precipitate first formed is redissolved; then caustic-potassa solution is added until an orange-yellow precipitate forms, which is then filtered off. The solution gives a white precipitate with ammonia. Com- pare with Nessler's reagent. Guyot (IODOFORM). A blue color develops on heating iodoform in a flask and passing the vapor through a heated tube con- taining starch. Hack-Kingzett (REAGENT). Cone, sulphuric acid and sugar (Pettenkofer's bile test) affords color reactions with benzene, camphor, clove oil and other ethereal oils, morphine, phenol, piperin, pyrogallol, salicylic acid, turpentine oil, etc.; e. g., on dissolving camphor in cone, sulphuric acid and adding cane sugar to the deep-red fluid, the solution solidifies and forms a pink'mass; on adding water to this the color disappears, and a ppt. insoluble in ether forms. Haensel (SOLUTION). A trace of acetic acid is added to Fol's picro-chromic acid solut. Haentsch (GLYCERIN MEDIUM). Glycerin, i part; alcohol, 3 parts; water, 2 parts. Hagen (STRYCHNINE). On adding sulphuric acid and lead dioxide to the suspected liquid, a bluish- violet color develops. Hager (ALBUMIN IN URINE). A solution of picric acid produces turbidity in urine containing albumin. Hager (ALCOHOL IN ESSENTIAL OILS), i. On shaking an essential oil containing alcohol with an equal volume of a mixture of water, i , glycerin, 2 (or a solution of sodium nitrate, i, in water, 3), and allowing to stand a while, the volume of oil will be diminished in proportion to the amount of alcohol present. 2. If a trace of tannin be added to 5 drops of essen- tial oil containing alcohol and, after shaking, the mixture is left for several hours at the ordinary temperature, the tannin will sink after becoming pasty and adhesive ; in the absence of alcohol, the tannin will continue to float, remaining solid and porous. 3. If a drop of oil be poured into water, a turbidity indicates presence of alcohol. H2 TESTS AND REAGENTS. Eager (ALCOHOL IN ETHER). Add a small fragment of fuchsine to the ether the latter, if pure, remains uncolored. Hager (ALKALOIDS). Solut. of picric acid produces precipitates in alkaloidal solutions. Solut. also used for albumin by over- laying urine in presence of albumin a turbidity is produced. Hager (AMMONIA). Solution of mercurous nitrate gives a brown color or a black ppt. with ammonia. Hager (AMYLIC ALCOHOL). On dipping a roll of filter-paper into alcohol containing fusel oil, and mixed with 10% of glycerin, the odor of amylic alcohol becomes very pronounced when paper is dried at a temperature not exceeding 25 C. Hager (ARSENIC), i. Arseniuretted hydrogen is evolved on heating a liquid containing arsenic with excess of potassa solu- tion, zinc, and a little magnesium ribbon. 2. An arsenica solution will develop a steel-colored to brown stain when heated to about 90 C. on thick tin-foil, after acidifying strongly with hydrochloric acid. 3 . When a substance or liquid con- taining arsenic is boiled with sodium chloride, ferrous chloride, and dilute sulphuric acid, arsenic chloride and hydrochloric acid are formed, and the arsenic may be tested in any con- venient way after passing the products of the reaction into water. 4. In the "Kramato" method, a bluish to black stain or violet ring is formed on letting a drop of a hydrochloric- acid solution of arsenic fall upon a strip of bright brass, copper, tin, or tin-foil, and heating moderately. See Reinsch's test. 5. The substance or liquid is placed in a test-tube with some diluted sulphuric acid and a small piece of zinc; the tube is then closed with a cork in which are two slits, into one of which a strip of lead- acetate paper is inserted, and into the other a strip of silver-nitrate paper. The lead paper will indicate sulphurous acid and the silver paper arsenic, the stains produced by the latter being unaffected by a io-% solution of potassium cyanide. Hager (BENZOIN IN BALSAM PERU). Dissolve i part balsam in 7 parts 70-% alcohol, and compare with sample of known quality (the more benzoin the lighter the color). Then dilute half with 4 or 5 volumes water and shake. The resulting fluid should retain its original turbidity for 3 days on standing at ordinary temperature; if the balsam contains resin, oil, or TESTS AND REAGENTS. 113 tar, the liquid will not be so turbid, and will show a ppt. either floating or at the bottom. Hager (BRUCINE). A yellowish to blood-red color develops on adding dilute sulphuric acid and manganese dioxide to a solution of brucine and filtering. The color is changed to violet on heating the filtrate with nitric acid in the presence of stannous chloride. Hager (BUTTER [ORGANOLEPTIC REACTION]). A cotton wick is saturated with the liquefied fat and ignited, the flame being extinguished after two minutes pure butter develops the odor of strongly-fried butter; margarin that of acrolein. Hager (CACAO BUTTER [ANILINE TEST]), i Gm. cacao butter is dissolved in 2 to 3 Gm. aniline, and set aside for i-J- hours at a temperature of 15 C. Pure cacao butter floats as a clear liquid layer on the aniline; if tallow, wax, stearin, or paraffin is present, the oily layer shows granular formations or has solidified entirely. Hager (CASTOR OIL IN COPAIVA BALSAM). Mix balsam with 4 volumes petroleum benzin on standing a few hours separa- tion takes place, as castor oil is not completely soluble in the petroleum benzin. Hager (CHLOROFORM IN ESSENTIAL OILS). Shake 15 drops of suspected oil with 50 to 60 drops alcohol, and 30 drops diluted sulphuric acid; then add a few pieces of zinc, and heat. When evolution of hydrogen ceases, add an equal volume of cold water, shake and run through a wet filter. If chloroform present in the oil, silver chloride will be pptd. on acidifying filtrate strongly with nitric acid, and adding silver-nitrate solution. Hager (CHOLESTERIN). See Salkowski's test. Hager (CITRIC AND TARTARIC ACIDS). Pour a solut. of potas- sium hydroxide, i, in water, 2, and alcohol, i, upon a glass plate, and place crystals of the acid at intervals of i to 2 inches. Citric acid dissolves almost entirely without losing its transparency within i or 2 hours; tartaric acid soon be- comes an opaque white. Hager (COLCHICINE). In concentrated solutions of colchicine, a solution of borax produces a white ppt. ; in dilute solutions H4 TESTS AND REAGENTS. the ppt. is not formed at ordinary temperatures, but upon heating to 50 C. Hager (COPPER IN VINEGAR). Add 15 drops solut. of potas- sium ferrocyanide to 15 Cc. vinegar on standing a few hours a brown ppt. deposits if copper present in traces; if much copper present, ppt. develops at once. Hager (DEXTRIN IN ACACIA). A blue color develops on boiling a liquid containing dextrin with ammonium molybdate and a little nitric or citric acid. Hager (ESSENTIAL OILS), i. Oils are distinguished by their varying solubility in alcohol, as indicated by the opalescence produced (See Proc. Am. Pharm. Assoc., 1882). 2. Shake 5 or 6 drops of the oil with 25 to 30 drops sulphuric acid, and note the heat and turbidity produced; on cooling, add 8 or 10 Cc. of 90-% alcohol, shake briskly, and note the color and turbidity . See Prescott ' s " Organic A nalysis . ' ' Hager (FATTY OILS IN COPAIVA BALSAM). Heat 5 to 10 drops of balsam in a watch-glass for 15 to 20 minutes at 110 to 120 C., and then cool if balsam good, the residue is hard and brittle; if fatty oils present, it is pasty or sticky. Hager (FIXED OILS). In the "elaidin" test the oil is shaken with an equal volume of 25-% nitric acid, a strip of copper added, and the mixture set aside at the ordinary temperature; note the appearance of the mixture at intervals of 1 5 minutes. See Prescott 's "Organic Analysis." Hager (FREE ACID IN ALUMINIUM SULPHATE). Shake the powdered salt with absolute alcohol the nitrate must not have an acid reaction. Hager (GALLIC AND TANNIC ACIDS). Add excess of sodium- phosphate solut. to liquid and add ferric chloride carbolic or salicylic acid causes no color, but gallic or tannic acid causes a violet color. Hager (GLUCOSE). Solution of 30 Gm. of red mercuric oxide, 30 Gm. of sodium acetate, 50 Gm. of sodium chloride, 25 Gm. of glacial acetic acid, and 400 Cc. of water, diluted to a liter. Solution containing glucose (diabetic urine) and boiled with reagent, yields a ppt. of mercurous chloride. Hager (GLYCERIN). An aqueous solut. glycerin colored blue by litmus tincture, when mixed with a solution of borax, also TESTS AND REAGENTS. 115 colored blue by means of litmus, assumes a red color. See Linde's test for glycerin. Hager (GURJUN BALSAM IN BALSAM COPAIVA). Mix i volume balsam copaiva with 5 volumes petroleum ether if gurjun balsam present, mixture becomes very turbid in a few minutes, and a voluminous precipitate deposits, becoming solid in a few days. With pure copaiva, a dust-like deposit forms after several hours. Hager (HYDRIDES OF SULPHUR, ARSENIC, ANTIMONY, AND PHOS- PHORUS). The hydrides formed by action of zinc and sul- phuric acid in presence of the substance tested are allowed to act on parchment paper moistened with silver-nitrate solut. If resulting brown or black spot is macerated with io-% potas- sium cyanide solution the color resulting from action of sul- phuretted hydrogen disappears at once; that resulting from the hydrides of antimony and phosphorus disappears grad- ually (i to 2 hrs.); that from the arseniuretted hydrogen not at all. Hager (HYDROCYANIC ACID IN AMYL NITRITE). Add 2 or 3 drops solut. silver nitrate to mixture of 10 drops amyl nitrite and 100 to 150 drops alcohol cloudiness or ppt. indicates presence of hydrocyanic acid. Hager (looic ACID IN NITRIC ACID). On adding to 3 Cc. of the suspected nitric acid, 3 drops sodium-sulphite solut. and after i minute, 5 Cc. of ammonia water with i drop silver-nitrate solut., a cloudiness or ppt. appears in the presence of iodic acid, and does not disappear on the addition of several Cc. ammonia water. Hager (MINERAL ACIDS). Vinegar containing free mineral acid leaves a crystalline residue on adding one-fourth its bulk ammonia and evaporating above 70 C. Hager (NITRIC ACID). A blue color is caused by molybdic acid and sugar. Hager (NITROBENZENE IN ESSENTIAL OIL ALMOND). Pure oil forms a clear solut. on gently agitating 10 drops with 10 Cc. 45-% alcohol; in the presence of nitrobenzene, solut. will be cloudy. Hager (NITROUS ACID). Carbolic acid with nitrous acid causes a red color, which changes to brown, then green. n6 TESTS AND REAGENTS. Hager (PHOSPHORUS). A black stain is caused on taking up phosphorus with ether or benzene, heating to 30 to 40 C., and exposing a strip of silver-nitrate paper to vapors given off. Hager (QUININE). On well shaking 2 Gm. pure quinine sul- phate with 20 Cc. cold water and filtering, then diluting ni- trate with equal bulk of water and shaking with 10 or 12 drops sodium-salicy late solut. (1:5), the solut. remains clear; other cinchona alkaloids, if present, cause cloudiness. Hager (SANTONIN). On well shaking 2 Gm. pure santonin with 6 Cc. water and filtering, then adding i or 2 Cc. sat. picric-acid solut., no cloudiness or ppt. should occur. Hager (SODIUM SALTS). White cloudiness is caused by sodium salts on adding a mixture of crystallized stannous chloride, 5, water, 10, and sufficient potassium-hydroxide solut. Test may also be employed to detect lithium and ammonium salts. Hager (STRYCHNINE). Sulphuric acid and lead peroxide give a bluish- violet color with strychnine. Hager (SUGAR IN GLYCERIN). A blue color develops on boiling 5 drops glycerin containing sugar with 100 drops water, 3 or 4 Cgm. ammonium molybdate, and i drop of 25-% nitric acid. Hager (TURPENTINE IN COPAIVA). i. Odor of turpentine becomes very apparent when i dram copaiva containing it is mixed with 5 or 6 drops water and sufficient litharge to make a thin paste. 2. Pure copaiva forms a clear mixture with 12 volumes of 90-% alcohol, and the mixture becomes turbid on adding 1 2 volumes more ; in presence of turpentine or other adulterant the result is different. Hager (POTABLE WATER). Addition of tannin solution (tannin, i, water, 4, and alcohol, i) to potable water should cause no turbidity, even after standing some time. Hager (WAX), i. Dissolve 0.5 Gm. wax in 5 Cc. chloroform a residue indicates presence of honey, prepared chalk, ocher, alumina, starch, sulphur, brick dust, lead oxide, lead car- bonate, gypsum, or water. 2. Boil wax with 15 parts of a mixture of water, i, and 90-% alcohol, 2, and cool; if cloudy, filter and mix with equal volume water. If resin present, it is dissolved by the alcoholic liquid; stearin, paraffin, and wax remain unaffected. 3. Shake 2 Cc. chloroformic solut. of wax with 12 to 15 Cc. lime water stearic acid forms a granu- TESTS AND REAGENTS. 117 lar lime soap, whereas the chloroform and wax form an emul- sion-like separate layer. 4. On heating wax in a test-tube, odors of acrolein develop if tallow present in the wax. Hager-Landolt (PARAFFIN IN WAX). Melt 2 Gm. wax in a wide test-tube, add 1.5 Gm. KOH dissolved in 4 Cc. water, and boil ij minutes with constant agitation; when some- what cool, add 8 Gm. benzene and shake vigorously, then add to the still milky fluid 5.5 Cc. cone, solut. lead acetate and shake. Decant the clear, separated benzene through cotton, and repeat shaking with fresh benzene. Evaporate benzene extracts, add to residue 6 Gm. cone. H 2 SO 4 , and heat on sand-bath till wax all carbonized, then let cool, add water, and collect undecomposed paraffin. Purify this by extracting with petroleum ether and evaporating sol- vent. Hahnemann (LEAD AND COPPER IN URINE). A black or brown ppt. is thrown down on shaking with a solut. made by dis- solving tartaric acid, i, in water, 64, shaking briskly for a while with calcium sulphide, i , and decanting. Haine (GLUCOSE). 3 Gm. copper sulphate, 9 Gm. potassa, 100 Gm. glycerin, and 600 Gm. water. Glucose (diabetic urine), upon the application of heat, precipitates red cuprous oxide from solut. Haines (GLUCOSE). The author states that the formulas pre- viously published are incorrect. The following are the proper proportions: Copper sulphate, 2 Gm.; glycerin, 20 Gm.; po- tassa, 9 Gm.; water, 175 Gm. Boil 4 Cc. of the solut. and add 6 to 10 drops (not more) urine, and boil again if sugar present a yellow or yellowish-red ppt. forms. Hairs (SACCHARIN IN PRESENCE OF SALICYLIC ACID). Ex- tract suspected liquid with ether, evaporate, take up ethereal residue with hydrochloric acid, and precipitate salicylic acid by bromine water; remove excess of bromine from filtrate by current of air, and isolate saccharin with ether; then identify saccharin by Bornstein's test. Haller-Bela (MACERATING MIXTURE). See Bela-Haller. Halphen (COTTONSEED OIL). Mix equal parts of suspected oil, amylic alcohol, and carbon disulphide containing i % sulphur, place in a test-tube, and plunge ^ or into boiling salt water n8 TEST$.AN.D RE A 'GENTS. after 10 to 15 minutes a red color develops if cottonseed oil present. Hamann (CARMINE SOLUTION). Add acetic acid to an ammo- niacal solut. of carmine until a ppt. begins to form, and filter the fluid before using. Addition of i to 2% chloral hydrate renders solut. more permanent. Hamilton (HEMATOXYLIN). Hematoxylin, 12 Gm.; ammonia alum, 50 Gm. ; glycerin, 65 Cc.; distilled water, 130 Cc. Boil the solut., and while hot add 5 Cc. liquid carbolic acid. Ex- pose mixture to daylight for a month to ripen it. Hamlin (ALKALOIDS). Color reactions are afforded on treat- ment with sulphuric acid and potassium chromate, followed by chlorinated lime. See Proc. Am. Pharm. Assn., 1881. Hammarsten (CAFFEINE IN URINE). Add 10 drops dil. sul- phuric acid to 500 Cc. urine, and evaporate to 40 Cc. Mix this with 120 Cc. 97-% alcohol, and let stand 12 hours, filter off alcohol, and evaporate. Shake residue with its volume benzene 3 or 4 times, and add to extract chlorine water and ammonia a violet color indicates presence of caffeine (theine). Hammarsten (GLOBULIN IN URINE). Globulin is pptd. by a sat. solut. magnesium sulphate, or by crystals of magnesium sulphate. Hammarsten (!NDICAN IN URINE). Mix urine with equal vol- ume fuming hydrochloric acid, add chlorinated-lime solut. drop by drop, and shake out mixture with chloroform. The latter takes up indigo resulting from the indican, and is col- ored blue. An excess of chlorinated-lime solut. is to be avoided. Also known as Jaffe's test. Hammarsten (METALBUMIN). Mixture of cone, sulphuric acid and acetic acid gives a violet color with metalbumin. Hammarsten-Robbert (THYMOL). Mix a solut. of thymol with half its volume glacial acetic acid and add equal volume sul- phuric acid, then heat a reddish-violet color develops. Hanaman (SLIDE-CLEANING SOLUTION). Add i volume strong sulphuric acid to 8 volumes potassium-bichromate solut. Hannay (CYANIDES). Titrate solut. made alkaline with ammo- nia with standard solut. mercuric chloride, containing 13.537 Gm. in 1,000 Cc. i Cc. = 0.0027 Gm. HCN. A faint turbidity indicates end of reaction. TESTS AND REAGENTS. 119 Hansen (HEMATEIN SOLUTION). Dissolve i Gm. hematoxylin crystals in 10 Gm. absolute alcohol, and add a solut. 20 Gm. potassa-alum in 200 Gm. distilled water. Then pour mixture into a porcelain capsule containing 3 Cc. cone, aqueous solut. potassium permanganate, heat to boiling-point with constant stirring, and after solut. has become dark reddish- violet con- tinue boiling for half a minute to a minute. When cool, solut. is ready for use. Hanstein (ANILINE STAIN FOR MICROSCOPIC PREPARATIONS). i . Equal parts methyl violet and fuchsine. 2. i part violet and 2 parts fuchsine. For use, a concentrated alcoholic solu- tion of the mixture is prepared. Hardy (ALCOHOL). A blue color develops on adding guaiac, hydrocyanic acid, and copper sulphate. Hardy (ALCOHOL IN CHLOROFORM). Hydrogen is evolved on adding metallic sodium. Harley (UROHEMATIN). i. Dilute urine of 24 hours to 60 fl. oz., or concentrate if volume greater. Add to 2 fl. dr. of urine fl. dr. nitric acid and let stand a pink, crimson, or purple color denotes excess of urohematin. 2. Boil 4 fl. oz. urine, and add nitric acid; when cool, heat in 6-fl.-oz. bottle with i fl. oz. ether, shake, and set aside for 24 hours a red color in ethereal solution indicates excess of urohematin. Harnack (IODINE IN URINE). A blue color develops on shak- ing with starch paste and carbon disulphide. Hartig (AMMONIA-CARMINE STAIN). Suspend carmine in dis- tilled water, and dissolve by gradual addition of ammonia water, then filter. Harting (PRESERVATIVE FLUID). An aqueous solut. of mer- curic chloride (i : 200 to i : 500). Haslam (ALBUMIN IN URINE). A whitish zone forms on mix- ing urine with a few drops solut. sodium chloride and overlay- ing with solut. ferric chloride. Hassalt (ACONITINE). A violet color develops on dissolving acon- itine in syrupy phosphoric acid and cautiously evaporating. Hatschett (COPPER). Traces of copper salts give with ferrocyanic acid and its salts a brown precipitate ( Hatschett 's brown). Hauchecorne (COTTONSEED OIL IN OLIVE OIL). Heat oil, 6 Gm., with 2 Gm. pure nitric acid, 40 Be., on a water-bath for 120 TESTS AND REAGENTS. 2 minutes pure oil remains unchanged or becomes lighter, and should solidify within 24 hours to a flesh-colored mass. Adulterated oil assumes an orange-brown red. The nitric acid must be free from nitrous acid. Haug (DECALCIFICATION SOLUTION). Mix i Gm. phloroglucin with 10 Cc. pure nitric acid (sp. gr. 1.4), and warm very slowly and carefully with gentle agitation. Dilute solut. with 100 Cc. distilled water and add 10 Cc. nitric acid. Hydro- chloric acid may be used instead of nitric acid, 30% of acid being used, and 0.5% sodium chloride should then be added. Haugk (THIOSULPHATES). Color of potassium-permanganate solut. is changed to bluish-green by thiosulphates. Hay (BILIARY ACIDS). Throw a little sulphur in fluid if bil- iary acids present, the sulphur sinks. Hayem (SOLUTION FOR FIXING BLOOD CORPUSCLES). Mercuric chloride, 0.5 Gm.; sodium chloride, i Gm. ; sodium sulphate, 5 Gm.; distilled water, 200 Cc. Hayem (SOLUTION FOR HYPODERMOCLYSIS). Sodium chloride, 75 grains; sodium sulphate, 150 grains; sterilized water, 40 fl. oz. Hefelmann (BOMBAY MACE). Basic lead acetate gives a white ppt. with an alcoholic extract of genuine mace ; with Bombay mace it gives a red ppt. According to Waage, however, this test is not always trustworthy. Hefelmann-Mann (FLUORINE IN BEER). Test depends upon precipitation of fluorides as calcium or barium fluoride. Upon treating ppt. containing fluorides with sulphuric acid, hydrofluoric acid is liberated and is recognized by its glass- etching properties. Hegler (LIGNIN). Sections are placed in alcohol, then treated with a hydro-alcoholic thallium-sulphate solut. lignin is colored orange-yellow; cellulose and cork remain uncolored. Hehn (CHLORAL REAGENT FOR VOLATILE OILS AND RESINS). Saturate 100 Cc. alcohol with chlorine, and partly remove the resulting hydrochloric acid by distillation. Then add sul- phuric acid and distil the resulting metachloral. Two drops of the latter when brought in contact with i drop of certain volatile oils or a fragment of some resins produce characteristic color reactions. See Dragendorff, Analysis of TESTS AND REAGENTS. 121 Plants. Oil of myrrh (or residue from the petroleum-ether extract of myrrh) produces a violet-red color with the reagent. Hehner (Acio NUMBER). Denotes the amount of insoluble fatty acids yielded by 100 Gm. of fat, and serves for the char- acterization of fats. Hehner (FORMALDEHYDE). Add i drop aqueous phenol solut. to suspected liquid, and overlay mixture on cone, sulphuric acid if formaldehyde present, a carmine-red zone forms at point of contact of two liquids. Hehner (FORMALDEHYDE IN MILK), i. Add some 94-% sul- phuric acid if formaldehyde present, a blue color develops. 2. Distil a part of the milk, add some peptone, and then sul- phuric acid. According to Leonard, the blue color appears only when a trace of ferric chloride or other oxidizer is present in the sulphuric acid. Hehner (MINERAL ACIDS IN VINEGAR). Add 25 Cc. decinor- mal alkali to 50 Cc. vinegar, evaporate to dryness, and ignite at low red heat to convert acetates into carbonate. Cool, add 25 Cc. decinormal acid, heat to expel CO 2 , and filter; wash filter, and titrate washings and filtrate with decinormal alkali each Cc. used equals 0.0049 Gm. H 2 SO 4 or 0.00364 Gm. HC1. Pure vinegar leaves an alkaline ash. Heidenhain (ALBUMIN). On pouring a dilute solution of violet- black into an acid solution of serum albumin or casein, a flocculent ppt. very rapidly forms, if any notable quantity of albumin is present. Even in a dilution of i : 20,000 a handsome, colored flocculent ppt. forms after a short time. For the detec- tion of albumin in urine, the latter is acidulated with 0.4-% acetic acid, while slightly heating, so as to change the albu- min to acid albumin. An excess of acetic acid hinders the reaction. With a supposed albumin-content of 1:1,000 to 1:5,000, 3 to 5 Cc. of a 2-% dye solution are added to 15 Cc. urine; in the case of an albumin-content of i : 10,000 to i : 20,000 only 3 Cc. of the aniline solution is employed; with a i : 40,000, 2 Cc. ; and with a solution of i : 60,000 solution, i Cc. is used. The acid aniline dye combines with the albumin, giving a ppt. Heidenhain (FIXING SOLUTION). Sodium chloride, 0.5-% solu- tion, is saturated with warm corrosive sublimate solut. 122 TESTS AND REAGENTS. Heidenhain (HEMATOXYLIN METHOD). a. Hematoxylin, i Gm.; distilled water, 300 Cc. b. Potassium chromate, i Gm. ; distilled water, 200 Cc. Small pieces of tissue hard- ened in alcohol or picric arid are placed in a for 12 to 24 hours, and then transferred for a similar length of time to b. Wash thoroughly in water, dehydrate in alcohol, and imbed in paraffin. Heidenhain (!RON HEMATOXYLIN METHOD). Sections are treated for -J- to 3 hours with a 1.5- to 4-% solut. iron alum, then washed with water and stained in a 0.5-% aqueous solut. hematoxylin. Rinse with water, and again treat with the iron solut. for 20 to 60 minutes. The sections are sometimes stained for 24 hours or more in a weak solution (i-%) of Bordeaux R., or aniline blue, before treatment with the iron alum. Heidenhain (NEUTRAL CARMINE). Prepare solut. according to Beale's formula, but with omission of alcohol, and render it almost neutral, either by cautiously adding dilute acetic acid or by driving off the free ammonia by warming on a water-bath. Heidenhain (SUBLIMATE SOLUTION). A 0.5-% solut. of sodium chloride is saturated while hot with mercuric chloride. Heidenreich (FIXED OILS). Various color reactions are pro- duced on mixing 10 or 15 drops of the oil with 2 drops cone, sulphuric acid. See also Heydenreich's test. Heijningen, Van- (QUININE). Ammonium-oxalate solut. affords a crystalline ppt. Heinrich (GLUCOSE). Dissolve mercuric iodide, 18 Gm., and potassium iodide, 25 Gm., in sufficient water; then add caustic potassa and water to make i ,000 Cc. On heating some of this solut. with suspected liquid, reduction occurs if glucose pres- ent. See also Sachsse's solut. Heinsius (ALBUMIN). Add i or 2 drops dil. acetic acid to 5 or 10 Cc. of suspected liquid and boil; then add sufficient sodium- chloride solut. to make liquid contain at least 4% sodium chloride if any albumin present, it will be precipitated. Heintz (POTASSIUM IN URINE). Acidulate 100 Cc. urine with hydrochloric acid, and add double the volume of a mixture of equal parts alcohol and ether containing some platinum chloride. In a few hours potassium-platinum chloride (and TESTS AND REAGENTS. 123 also the corresponding ammonium salt) crystallizes as octa- hedra, which may be identified under the microscope. Heintz-Ragsky (UREA). On heating urea with acids or caustic alkalies it is converted into ammonium carbonate. The CO 2 which may be liberated from the latter is used for calculating the quantity of urea that was present (CH 4 N 2 + 2H 2 = [NHJ.COJ. Heise (KERMES COLORING IN WINE). Shake 20 Cc. of the wine with 10 Cc. of a io-% alum solut. and 100 Cc. io-% sodium-carbonate solut.; then exactly neutralize with the latter solut. The filtrate gives the following reactions if kermes coloring matter present: Amyl alcohol extracts no color from acid or alkaline solutions; a solut. acidulated with acetic acid is not altered by sodium bisulphite, or colored yellow by caustic alkali. The coloring matter of beet-root gives similar reactions. Helch (PILOCARPINE HYDROCHLORATE). About 0.01-0.02 Gm. pilocarpine hydrochlorate (small quantities give to the ben- zene a distinct violet color, larger quantities a blue color) are dissolved in a little dist. water in a test-tube, i to 2 Cc. H 2 O 2 of acid reaction added, the liquid then overlaid with about 2 Cc. benzene, and finally a few drops of a very dilute solution of K 2 Cr 2 O 7 (i Cc. to contain about 0.003 Gm. K 2 Cr 2 O 7 ) are added. The mixture is immediately shaken carefully and allowed to settle; if pilocarpine hydrochlorate be present the benzene is colored very distinctly violet. The reaction is so sensitive that o.oi Gm. is sufficient for detecting the presence of pilocarpine hydrochlorate. The author tested a whole series of substances, some alkaloids and their salts, and some of the newer remedies, but none of the substances examined afforded the violet color similar to that of pilocarpine, with the excep- tion, however, of pyridine. Quinoline salicylate gives a dirty- violet, turbid color, which however completely vanishes, while antipyrine, migranine, and salipyrin, examined under conditions similar to those under which pilocarpine was exam- ined, give a dark-blue color to the benzene, so that these above- named substances, by this test alone, can be distinguished from pilocarpine. Heller (ALBUMIN IN URINE). Albuminous urine, when over- 124 TESTS AND REAGEUTS. laid upon heated nitric acid, shows a white zone at the point of contact. Heller (BILIARY PIGMENTS). Mix 6 Cc. hydrochloric acid with enough urine to color, and allow nitric acid to flow down side and form a lower layer a play of colors denotes presence of biliary pigments. Heller (GLUCOSE). Glucose solutions or urine containing glu- cose are colored yellow to reddish-brown on heating with caustic potassa. See Moore's test. Heller (HEMOGLOBIN). Urine rendered strongly alkaline with caustic-potassa solut. yields on boiling, when hemoglobin is present, a red ppt. of earthy phosphates. Heller (!NDICAN IN URINE), i. Add 4 Cc. urine to 2 Cc. cone, hydrochloric acid with constant stirring, and then let stand a violet or blue develops if indican present. (If bile present, remove by pptn. with lead acetate, and nitration.) 2. Gen- tly heat 4 Cc. hydrochloric or nitric acid in test-tube, and overlay with urine free from albumin a violet or blue color develops. Heller (UROPHAINE IN URINE). Pour 4 Cc. urine upon 2 Cc. sulphuric acid in a beaker, from a height of about 4 inches a black or opaque color indicates excess; a pale garnet-red diminution. Heller-Moore (GLUCOSE). See Moore-Heller. Heller-Teichmann (BLOOD IN URINE). Urine containing blood, when heated to boiling with a drop acetic acid, forms a brown- ish-red to blackish coagulum. If to boiling hot liquid a little caustic-soda solut. is added, it becomes clear and yields a sed- iment of earthy phosphates that, from the adhering coloring matter of the blood, appears red to brownish-red in trans- mitted, greenish by reflected light. Helwig (BLOOD). Solut. potassium iodide, i part, in 4 parts water, removes dried-up and old blood stains, without altering coloring-matter of blood. Helwig (SOLANINE). A cherry-red color develops on adding a mixture of equal volumes sulphuric acid and alcohol. Hempel (IODIDES). A rose-red color develops on adding ferric- chloride solut., sulphuric acid and starch paste, to a liquid containing an iodide. TESTS AND REAGENTS. 125 Hendrix (SANDAL OIL). Mix 0.5 Cc. oil with 2 Gm. solut. of 3 parts cryst. carbolic acid in i part alcohol, add 0.5 Gm. cone, hydrochloric acid and shake pure sandal oil gives a yellow zone at contact-point ; copaiva gives a mauve ; cedar oil yields a milky solut. and brown color. Henking (EXAMINATION LIQUID FOR OVA). Distilled water, 80 Cc.; glycerin, 16 Cc.; formic acid, 3 Cc.; osmic acid (i-%), i Cc.; dahlia, 0.04 Gm. Henle (STAIN FOR NERVOUS TISSUE). Sections are left in palladium-chloride solut. (1:300 to i : 600) till they are of a straw color, then rinsed in water and stained with strong ammonia-carmine. Henneguy (ALUM CARMINE). Excess of carmine is boiled in saturated solut. potassa alum, and 10% of glacial acetic acid added on cooling. Allow to settle for some days, and then filter. Henneguy (PERMANGANATE METHOD). Treat sections for 5 minutes with i-% potassium-permanganate solut.; then wash in water and stain with safranine, rubin, gentian violet, or vesuvine, preference being given to a safranine solut. pre- pared with aniline water. Henninger (NITROBENZENE IN ESSENTIAL OIL ALMOND). Caustic-potassa solut. causes a green color. Henocque (GOLD PROCESS). Impregnate tissues with a 0.5-% solut. gold chloride; then wash in water for 12 to 24 hours, and reduce with the aid of heat (40 to 50 C.) in nearly satu- rated solut. tartaric acid. Henry (IODINE). Potassium - permanganate solut. liberates iodine. Henry, De- (INDICATOR). By monochromatic light afforded by sodium flame, red litmus color appears colorless; the blue appears black. Henry-Humbert (IODINE; BROMINE). Add acidified silver- nitrate solut. to water containing iodine or bromine; mix ppt. with silver cyanide, and pass current of dry chlorine over it cyanogen iodide or bromide is formed. Henzold (GELATIN IN FRUIT JELLIES). Boil material with water, filter, boil filtrate with excess of io-% solut. potas- sium bichromate, cool, then add 2 or 3 drops cone. H 2 SO 4 126 TESTS AMD REAGENTS. if gelatin present a white flocculent ppt. forms and gradually collects in a lump at bottom of liquid. Pectinous matters from plants do not give the reaction. Herapath (QUININE REACTION). Alcoholic solutions of quinine yield on addition of tincture of iodine a crystalline ppt. of quinine iodosulphate. This separates in thin plates, green at ordinary temperatures, brownish-red at 100 C. and pos- sessing strong polarizing properties. For microscopical exam- ination of the urine, the latter, after being rendered alkaline, is shaken out with ether, the ethereal solut. evaporated, and a portion of residue dissolved on a cover-glass in a drop of a mixture of 11.25 G" m - acetic acid, 3.75 Gm. alcohol, and 6 drops diluted sulphuric acid. To this is added a drop of tincture of iodine. Herbst (ACONITINE). Upon carefully concentrating a phos- phoric-acid solut. of aconitine containing aconine, a dirty- violet color is produced. Pure crystallized aconitine does not give this reaction. Herbst (ATROPINE). On adding sulphuric acid, potassium bichromate (or ammonium molybdate) and a little water, odor of essential oil almond develops. Also known as Herbst- Pfeifjer test. Hermann (FORMALDEHYDE SOLUTION). A i-% solution, ob- tained by diluting formaldehyde with 40 volumes of water. Hermann (PLATINO-ACETO-OSMIC MIXTURE). 15 parts i-% platinic chloride solution, i part of glacial acetic acid, and 2 and 4 parts of 2-% osmic acid. Hermann (TUBERCLE STAIN). Place cover-glass preparation in heated Hermann's solution for not longer than i minute, then for 4 to 5 seconds in io-% HNO 3 . Wash in 95-% alco- hol, and after-stain in eosine (i Gm. to 100 Cc. 60- % alcohol) for half a minute. Hermann (VIOLET AMMONIA-CARBOLATE). a. Crystal violet, i Gm. ; 95-% alcohol, 30 Cc. b. Ammonium carbonate, i i Gm.; dist. water, 100 Cc. Add enough of solut. a to solut. b to produce a dense stain on filter-paper. Hermann-Boettger (STAINING PROCESS). See Flemming's process. TESTS AND REAGENTS. 127 Herse (CODEINE). Dissolve substance in sulphuric acid and add solut. ferric chloride a blue color develops with codeine. Hertwig (MACERATING FLUID). Mix equal parts of 0.05-% osmic acid and 0.2-% acetic acid. Medusae are treated with this mixture for 2 or 3 minutes, then washed in o.i-% acetic acid until free from osmic acid. Leave 24 hours in the dilute acetic acid, then wash in water, stain with Beale's carmine and mount in glycerin. For Actiniae use 0.04-% osmic acid and make both solutions with sea water. Wash out with 0.2-% acetic acid, and stain with picro- carmine. Hertz (VEGETABLE COLORING MATTER IN WINE). Shake 10 to 15 Cc. red wine with 5 Cc. sat. solut. tartar emetic natural wine affords a cherry-red color by both reflected and transmitted light; foreign coloring matters give violet shades. Herzberg (FREE ACIDS). Paper tinted with Congo red turns bluish to bluish-black in the presence of free acids. Herzberg (PAPER). Wood pulp and jute give a lemon-yellow color with dilute solut. iodine in potassium iodide; linen, hemp and cotton papers, a brown color; while wood, cellulose, straw and esparto remain colorless. Strips of the paper are first boiled to a pulp with dilute potassa solut. and then washed free from alkali before applying reagent. Hemp, cotton, jute and linen give a yellow color with zinc-chloride- iodine solution ; cellulose gives a bluish color. Herzberg (TEST-PAPER). Congo-red papers (blue and red). Alkalies give a red color, and acids a blue. Also known as RiegeVs paper. Hesse (ALLIED ALKALOIDS IN QUININE). These alkaloids are less soluble in ether than quinine, while their sulphates are more readily soluble in water than the corresponding quinine salt. Shake 0.5 Gm. quinine sulphate with 10 Cc. water of 50 to 60 C.; after standing for 15 minutes, filter off 5 Cc., then add i Cc. ether (sp. gr. 0.7203) and 5 drops ammonia water (sp. gr. 0.96). The presence of quinidine, cinchonine, etc., is indicated by immediate or gradual formation of crystals in ethereal layer. Hesse (CHOLESTERIN). See Salkowski's test. 128 TESTS AND REAGENTS. Hesse (CODEINE). A blue color develops on dissolving in sul- phuric acid and adding ferric-chloride solut. Hesse (MORPHINE IN QUININE SULPHATE). Mix suspected sulphate with diluted nitric acid (1:4) if morphine present yellowish to orange-red color develops. Hesse (QUINIDINE). Treat 0.5 Gm. pure quinidine with a solut. of 0.5 Gm. potassium iodide in 10 Cc. hot water, filter after i hour, and then add i drop of ammonia no cloudiness should be produced. Hessert (STAINING FLAGELLA). Fix film by treating cover- glass preparations with a saturated alcoholic solut. mercuric chloride, wash, and stain for 30 or 40 minutes in a hot io-% aqueous or saturated alcoholic solut. fuchsine. Heurck, Van- (MOUNTING MEDIUM). This is simply mono- bromide of naphtalin. Heuschen (AMYGDALIN). Reduce suspected substance to fine powder, then add a little chalk, coarse rye flour, and water, and allow to ferment. If amygdalin present hydrocyanic acid will be evolved and stain cuprous guaiac paper blue. Heut (DIFFERENTIATING CONIINE AND NICOTINE). Add i drop cone, alcoholic solut. phenolphtalein to suspected liquid no reaction occurs with nicotine, but if trace of coniine present a red color develops; difference more marked on adding chlo- roform. Heydenreich (COTTONSEED OIL IN OLIVE OIL). Allow a few drops of the oil to fall on some pure sulphuric acid in a porce- lain capsule with pure olive oil, the point of contact is yel- lowish-green ; with foreign oils (cottonseed oil) it is yellowish- orange to brown. Heynsius (ALBUMIN IN URINE). Boil 5 to 10 Cc. of filtered urine with a few drops diluted acetic acid and then add a satu- rated solut. common salt a white ppt. results if albumin present. Hickson (EOSINE-HEMATOXYLIN METHOD). Stain sections on slide for i hour with a strong solut. eosine in 90-% alcohol, then wash with alcohol and stain for 20 minutes in a weak solut. of hematoxylin. Hilger (ALBUMIN). A ppt. forms on acidifying with acetic acid and adding potassium-ferrocyanide solut. TESTS AND REAGENTS. 129 Hilger (ARSENIC). A black stain develops on acidifying strongly with hydrochloric acid, adding excess of aqueous iodine solut., introducing a piece of pure zinc, and exposing silver-nitrate paper to the gas evolved. Hilger (BILIARY PIGMENTS). Ppt. coloring matter by boiling with barium hydrate. The yellow ppt. filtered off and washed, gives the following reactions : With alcohol and a few drops of sulphuric acid, ppt. becomes colorless while the solution be- comes green; with nitric acid containing nitrous acid, green and blue colors result. Hilger (loDic ACID IN NITRIC ACID). On diluting with water and shaking with 25% carbon disulphide, in presence of a few pieces of rasped tin, the disulphide is colored violet. Hilger-Mai (KERMES COLORING IN WINE). Mix 5 Cc. of wine with 10 drops of a 5-% solut. of iodine in potassium iodide, filter mixture after standing for 2 hours, and treat filtrate with sodium thiosulphate in excess. Natural wine is decolorized, but kermes gives a red color not destroyed on addition of sul- phuric acid. Himmelmann (ARSENIC). This is Marsh's method, modified by substitution for the acid and zinc of an ammoniacal solut. ammonium chloride which has been heated gently with a mix- ture of equal parts granulated zinc and powdered iron. The liquid containing arsenic is made neutral or alkaline before adding, and arseniuretted hydrogen is evolved. Himly (ILLUMINATING GAS IN WATER). Add chlorine water to suspected liquid, expose to sunlight, and remove free chlo- rine by adding mercury or mercury oxide. If mixture ex- hibits an odor of ethylene chloride or similar compound, illuminating gas was present in the water. At least 500 Cc. water should be used in this test. Himly (MINERAL SUBSTANCES IN FLOUR). Shake the flour with chloroform, allow to deposit, and examine sediment. Himly (OILED WHEAT). On shaking the grain with bronze powder and rubbing with filter-paper only the oiled grains will appear bronzed. Hindenlang (ALBUMIN IN URINE). Strong metaphosphoric acid causes an opalescent cloudiness or produces a ppt. in urine containing albumin. 13 TESTS AND REAGENTS. Hinsberg-Autenrieth (PHENACETIN). See Autenrieih-Hinsberg. Hinterberger (ATROPINE). A blood-red color develops on passing a current of cyanogen into an alcoholic solut. of atropine. Hirsch (PHENOL). A purple color develops on adding tincture of ferric chloride to an aqueous solut. of phenol. Hirschsohn (ACETANILID IN PHENACETIN). o.i Gm. phenace- tin is dissolved in 10 Cc. water, the solut. filtered after cool- ing, and treated with bromine water until a yellow color results. If the solut. becomes turbid, acetanilid was present (formation of parabromacetanilid). Hirschsohn (ALOES), i. i drop io-% solut. CuSO 4 and i drop H 2 O 2 added to 10 Cc. aq. i : 1,000 solut. aloes gives on boiling, a raspberry-red color with all varieties of aloes. 2. Boil 10 Cc. aloes solut. with i drop CuSO 4 solut. and i drop 1:15 solut. potass, ferricyanide, and filter filtrate is either yellow- ish or pink (latter is afforded by Curacao, Barbadoes, Zanzi- bar and Natal aloes). 3. Curacao and Barbadoes aloes give with CuSO 4 and potass, sulphocyanate a raspberry-red color at ordinary temperatures but much more pronounced on heat- ing. 4. Natal aloes boiled with borax solut. gives a red color. 5. Tinct. aloes, after exposure to sunlight for some time, no longer affords the reaction with CuSO 4 and H 2 O 2 . Hirschsohn (BENZOINS). Siam benzoin is colored cherry-red by cone, sulphuric acid; other benzoins are colored brownish- red. Siam benzoin with sulphuric acid gives a clear, violet solution on admixture of alcohol, and on adding water next, violet-red flocks form. Sumatra and Penang benzoins treated similarly give reddish-violet solutions and dirty- violet flocks. Hirschsohn (CASSIA OIL). Run 10 Cc. oil into a special flask with narrow neck graduated to 6 Cc. in tenths, and nearly fill flask with almost boiling sodium-bisulphite solut. Shake well, and when reaction moderates add more hot bisulphite, then immerse flask in boiling water until non-aldehydes have sepa- rated as a perfectly clear layer. Adjust lower surface of layer to zero mark on scale by adding more bisulphite, and read off the volume. The difference between this and 10 Cc. repre- sents quantity of cinnamic aldehyde in oil. TESTS AND REAGENTS. 131 Hirschsohn (CHLORAL ALCOHOLATE IN CHLORAL HYDRATE). i Gm. chloral hydrate is tested with i Cc. nitric acid (sp. gr. 1.38). If at ordinary temperatures, or upon warming, a yel- low color results within 10 minutes, alcoholate was present. Hirschsohn (COTTONSEED OIL). Heat 5 Cc. of oil for 20 min- utes on the water-bath with 6 to 10 drops of a solut. of i Gm. gold chloride in 200 Cc. chloroform presence of cottonseed oil is indicated by development of a red color. Hirschsohn (DIFFERENTIATING TARS), i. Completely soluble in 95-% acetic acid. (A) : Turpentine oil (French) dissolves it completely. The pe- troleum-ether extract of the tar is colored greenish by shak- ing with a diluted solut. (i : i ,000) of copper acetate. Chlo- roform and absolute ether dissolve it completely Pine tar (B): Turpentine oil dissolves it only partially. The petro- leum-ether extract is not colored by copper-acetate solut. Chloroform and absolute ether do not entirely dissolve it Beech tar 2. Not completely soluble in 95-% acetic acid. (A): Turpentine oil dissolves it completely, [a]: Aniline dis- solves it completely. Aqueous extract (1:20) yields a red. color with ferric-chloride solut. (i : 1,000) .Juniper tar [&]: Aniline does not dissolve it completely. The aqueous extract is colored greenish by ferric chloride Birch tar (B): Turpentine oil dissolves it only partially. Benzene, chloroform, ether, and olive oil dissolve it only par- tially Aspen tar Hirschsohn (DRAGON'S BLOOD). The alcoholic extract has a pure red color; that of other resins is usually reddish-yellow. Hirschsohn (FATTY OILS IN BALSAM OF COPAIBA). 20 to 40 drops of the balsam are boiled with i to 2 Cc. of a solut. of i part NaOH in 5 parts 95-% alcohol. The presence of oil is indicated by gelatinous ppt. or turbidity on cooling, or upon addition of 2 volumes of ether. Pure copaiba balsam with 3 volumes of 90-% alcohol should yield a mixture from which no oil globules should separate within an hour. Hirschsohn (GURJUN BALSAM IN COPAIBA BALSAM), i vol- ume of balsam, 3 volumes 95-% alcohol and i Gm. crystallized stannous chloride are boiled together until a complete solut. 132 TESTS AND REAGENTS. results. Admixtures of gurjun balsam are shown, by appear- ance of a red color, changing to blue on standing some time. Hirschsohn (GURJUN BALSAM). Two Cc. solut. cone, sulphuric acid in acetic ether (1 + 5), added to 3 to 4 drops gurjun bal- sam, causes a violet color. For testing copaiba balsam, 6 to 8 drops of balsam are added to a solut. of 2 drops sulphuric acid in 4 Cc. acetic ether a violet color indicates presence of gurjun balsam. Hirschsohn (PERU BALSAM), i. Balsam heated on water-bath half an hour with half its volume calcium hydrate should not solidify. 2. One volume balsam with 4 volumes 80- % acetic acid must give only an opalescent or cloudy solution from which no oily drops should separate in 2 hours. 3. The petroleum-ether extract shaken with copper-acetate solut. (1:1,000) must not be colored bluish-green or green. 4. Residue from petroleum-ether extract should not be colored by hydrochloric acid, sp. gr. 1.19. Hirschsohn (QUININE AND QUINIDINE). Reaction consists in the addition of one drop H 2 O 2 solut. (about 2-%) and i drop of io-% CuSO 4 solut. to the neutral alkaloidal solut. (chlo- ride or sulphate); on boiling, an intense raspberry-red color appears, changing to bluish violet, then blue, and, after a while, slowly to green. The limit of sensibility is i : 10,000. As in every such test it is highly important to know upon what other substances it has been tried, the following list in- creases the value of the reaction very considerably: A color- less or only faintly yellow solution is obtained with antipyrine, atropine, aconitine, acolyctine, asaron, brucine, berberine, bebeerine, caffeine, cocaine, cinchonidine, cinchonine, cincho- namine, cinchotenine, codeine, colchicine, colocynthin, con- vallamarin, convallarin, coumarin, cubebin, caryophyllin, delphinine, daturine, digitin, digit alin, duboisine, gelsemine, helenin, hyoscine, hyoscamine, kosin, meconin, minispermine, piperin, picrotoxin, pilocarpine, quassiin, quinoline, solanine, saponin, santonin, salicin, senegin, scoparine, sabadilline, sparteine, strychnine, taxine, theobromine, urson, vanillin, and veratrine. The following give yellow to brown: Analgen, apomorphine, arbutin, aesculin, chelerythrine, cotoin, du- boisine (amorphous), eserine, hydrastine, hydrastinine, mor- TESTS AND REAGENTS. 133 phine, narceme, narcotine, paracotoin, papaverine, peuce- danin, phloridzin and pyrodin. A light onion-red is pro- duced by thalline, an intense blue by kairine, and a light blue by asparagine. The peculiar raspberry-red tint is observed with euquinine, but only feebly, so that this color when strongly developed seems quite characteristic of quinine or quinidine. Hirschsohn (RosiN IN GUAIAC RESIN AND BALSAM OF TOLU). The finely-powdered sample is shaken for 10 to 15 minutes with 4 to 5 times its weight petroleum ether ; aqueous copper- acetate solut. causes a green color in filtrate if rosin present. Histed (ALOINS). On adding a few grains barbaloin to several drops of cone, sulphuric acid and gently passing over the surface a glass rod moistened with nitric acid, a red color develops; nataloin causes a blue color. Histed (NATALOIN). If nataloin is dissolved in cone, sulphuric acid and a small fragment potassium nitrate added, a green color develops, changing to red and then to blue. Hlasiwetz (HYDROCYANIC ACID). If an alkaline cyanide solu- tion is warmed with picric acid, a blood-red color results. Hoehnel, Von- (LIGNIN). Phenol-hydrochloric acid (highly cone, solut. of phenol in fuming hydrochloric acid) gives a green color with lignin. Hoehnel, Von- (SILK). A saturated solut. chromic acid diluted with an equal volume of water. Mulberry-red silk is dis- solved by heating for less than a minute in this solut.; wild silk is insoluble in the reagent; sheep's wool is dissolved like mulberry silk. Hofer (NARCOTIZATION SOLUTION). Dissolve hydroxylamine hydrochlorate (or sulphate) in water, neutralize with sodium carbonate and dilute to a i-% solut. Solut. is further reduced, according to organisms to be killed. Hoffmann (ALBUMINS AND PHENOLS). Solut. of mercuric nitrate containing a trace of free nitrous acid. Yields simi- lar color reactions as Millon's reagent. See Hoffman's reac- tion for tyrosin. Hoffmann (ALBUMIN TEST-PAPER), a. Dissolve corrosive sublimate, i part, in distilled water, 20 parts, b. Dissolve potassium iodide, i part, in distilled water, 2 parts. Mix solutions; impregnate paper with mixture and dry. Pre- J34 TESTS AND REAGENTS. pared paper, dipped into albuminous urine immediately causes a ppt. in acid urine if necessary, add a little acetic acid. Hoffmann (ALKALOIDS AND ANILINE SALTS), i. Aniline salts are distinguished from alkaloids by not affording ppts. with potassium iodide, potassium-cadmium iodide, and mer- cury-potassium iodide, but giving with solut. of sodium phospho-molybdate in sulphuric or oxalic-acid solut. a ppt. at first yellow, then blue, and yielding a blue solution with ammonia water. 2. Tannic acid only partially ppts. aniline salts. 2. Alcoholic mercury-chloride solut. causes in alco- holic aniline solut. a white, crystalline ppt. nearly insol. in water. Hoffmann (ANILINE REACTION). With fuming nitric acid, aniline gives a deep blue solution, becoming yellow and finally red upon warming. Hoffmann (BENZENE). Heat with fuming nitric acid, subject the resulting nitrobenzene to the action of alcohol, hydro- chloric acid, and granulated zinc, then test the aniline pro- duced with chlorinated lime. Hoffmann (BLUE STAIN). Hoffmann's blue, i Gm.; alcohol, 20 Cc.; distilled water, 80 Cc.; glacial acetic acid, 0.5 Cc. As a nuclear stain immerse sections for 10 minutes, rinse in water, wash in 90-% alcohol, dehydrate, clear, and mount in balsam. To stain sieve areas, stain sections 5 or 10 min- utes, rinse in distilled water, and mount in glycerin; or, dehy- drate, clear, and mount in balsam. Hoffmann (CARBON BISULPHIDE). Triethyl phosphine gives a rose-red color. Hoffmann (CHLOROFORM), i. Isonitrile is formed on adding aniline, alcohol, and soda. 2. When a trace of ammonium chloride and ferrous chloride is warmed with an excess of alco- holic potassa solution and a few drops chloroform, and the mixture then diluted with water and acidified with hydro- chloric acid, a greenish-blue color results. Hoffmann (INDICATOR). The color of eupittonic acid is changed from yellow to blue by alkalies, and to red by acids. Hoffmann (PHENOL). Cautiously overlay 2 Cc. of the liquid on an equal volume sulphuric acid, and drop into the liquid TESTS AND REAGENTS. 135 a few crystals potassium nitrate the violet color may appear in streaks. Hoffmann (PRIMARY AMINES), i. These yield upon warm- ing with chloroform and alcoholic potassa solution the char- acteristic odor of isonitrile. 2. On evaporating an ethereal solution of a primary amine base with carbon disulphide, dis- solving the residue in water, and boiling solut. with silver ni- trate, mercuric chloride, or ferric chloride, an odor of mustard oil develops. Hoffmann (TYROSIN). The hot aqueous solution of tyrosin (obtained from the urine sediment) yields a red color and ppt. on addition of a solut. of mercuric nitrate with some potassium nitrate. Hoffmann- Ultzmann (BILIFUSCIN). Dip piece of clean white linen in urine and allow to dry. Linen is colored brown if bilifuscin present. Hoffmeister (CELLULOSE SOLVENT). Mixture consists of hydro- chloric acid and potassium chlorate. Hofmeister (CREATIN). Phosphotungstic acid gives a readily soluble, crystallizable compound with creatin; with creatinine a difficultly soluble compound is formed. Hofmeister (LEUCINE). Heat solut. with mercurous nitrate if leucine is present, a deposit of metallic mercury forms. Hofmeister (PRECIPITANT FOR PEPTONE). Commercial so- dium tungstate is dissolved in hot water, phosphoric acid added to acid reaction, then strongly acidulated with hydro- chloric acid and filtered after standing 24 hours. Hoggan (FERRIC-CHLORIDE STAIN). Treat tissue first with silver-nitrate solut. (previously exposed for a short time to diffused light), then dehydrate in alcohol, and then treat for a few minutes with 2-% alcoholic solut. ferric chloride. Next treat with 2-% alcoholic solut. pyrogallic acid, and when dark enough, wash in water and mount in glycerin. Holde (TARRY CONSTITUENTS OF LUBRICANTS OBTAINED FROM PETROLEUM). Dissolve in petroleum ether in which the tarry admixtures are insoluble. Holde (UNSAPONIFIABLE SUBSTANCES IN FATS). Boil a piece of caustic potassa the size of a pea in 5 Cc. absolute alcohol until completely dissolved, add 3 to 4 drops of the fat, and I3 6 TESTS AND REAGENTS. then boil the whole for i minute. Upon diluting with 3 to 4 Cc. of water, a turbidity indicates the presence of an unsapon- ifiable substance. Honsell (SMEGMA BACILLUS STAIN). Stain in boiling carbol- fuchsine 2 min., rinse in water, dry, treat with a mixture of 97 parts alcohol and 3 parts HC1 for 10 min., rinse in water, counterstain in equal parts of saturated alcoholic solut. methylene blue and water. Only tubercle bacilli are stained red, smegma bacilli are not. Hopkins (URIC ACID). Saturate 100 Cc. urine with finely pow- dered ammonium chloride (about 30 Gm.) let stand 2 hours with occasional stirring, then filter, and wash with saturated solut. ammonium chloride; then rinse off filter with hot water, heat just to boiling with excess dilute HC1, cool, and let stand 2 hours. Collect crystals of uric acid, wash twice with cold water, then with alcohol, until free from acidity, dry at 100 C., and weigh. Add o.ooi Gm. for every 15 Cc. of mother liquor. If preferred, the acid ammonium-urate ppt. from above may be titrated. Treat ppt. obtained as above from 200 Cc. urine with known volume decinormal sulphuric acid, boil, cool, dilute to 200 Cc., add little methyl orange, and titrate back with semi- decinormal alkali. Difference between volume required and volume of acid solut. represents ammo- nia of ppt., the uric acid having no action on methyl orange. Each Cc. semi-decinormal soda solut. = 0.0084 Gm. uric acid. Hoppe-Seyler (BILIARY PIGMENTS). Ppt. urine with milk-of- lime, then ppt. the lime with carbonic acid, filter off, and wash the ppt. with water. If nitroso-nitric acid is dropped upon the ppt. in the filter, the well-known color reactions are produced if biliary pigments are present. See Gmelin's test. Hoppe-Seyler (CARBON-MONOXIDE POISONING). A few drops of the blood to be tested are mixed in a porcelain capsule with an equal or double quantity of cone, caustic-soda solut. blood containing carbon monoxide will appear of a vermilion color in thin layers, while normal blood will appear a dirty brownish-green. Hoppe-Seyler (PHENOL). A pine shaving is colored blue when moistened with phenol and hydrochloric acid. Tommasi's TESTS AND REAGENTS. 137 modification: Instead of hydrochloric acid, a mixture of 50 Cc. hydrochloric acid, 50 Cc. water, and 0.2 Gm. potassium chlorate is used. Hoppe-Seyler (SANTONIN IN URINE). Treat urine with caustic so da a r ed color develops; add amylic alcohol red color disappears (distinction from chrysophanic acid, which amylic alcohol does not decolorize). Hoppe-Seyler (SUGAR IN THE URINE). Test depends upon for- mation of indigo upon warming urine containing glucose with orthonitrophenylpropiolic acid. Reagent employed is a 0.5-% solut. of this acid in soda lye. Five Cc. of the solut. are boiled with 10 drops urine; sugar, if present, develops an indigo color. Hoppe-Seyler (XANTHINE). Calcium chloride and sodium- hydrate solut. added to a solut. containing xanthine, give at zone of contact a dark green color, quickly changing to brown, and finally disappearing. Horsford (GLYCOCOLL). A bright red color develops on heating with potassium-hydroxide solut. Horsley (ALKALOIDS). Sodium nitroprussiate yields crystalline precipitates. Horsley (GLUCOSE), i. Dissolve copper sulphate, 30, in water, 1440, add tartaric acid, 30, and cool; then add potas- sium hydroxide, 90, and potassium carbonate, 90. This solut. is reduced by glucose. 2. A green color develops on boiling glucose with a solut. of potassium chromate contain- ing free alkali. Horsley (MORPHINE), i. A red color forms several hours after adding potassium-ferricyanide solut. 2. A blood-red color develops on adding a few drops silver-nitrate solut. and adding nitric acid to filtrate after reduction of the silver. Horsley (NITRIC ACID). Pyrogallic and sulphuric acids yield a violet color with aqueous solutions containing traces of a ni- trate. Horsley (STRYCHNINE). A purple- violet to red color forms on adding potassium-bichromate solut. to a solut. of a strychnine salt, and, after separation of crystals, adding a drop of sul- phuric acid. Hosaeus (BORAX OR SODIUM BICARBONATE IN MILK). Add 138 TESTS AND REAGENTS. o.i Gm. tartaric acid to 100 Cc. milk, shake, and heat if milk does not curdle, the presence of borax or sodium bicarbonate may be assumed. Houzeau (OZONE PAPER). This is red litmus paper, one-half of which has been saturated with potassium-iodide solution. Since ozone liberates free alkali from potassium iodide, the paper will turn blue in the presence of this gas. How (ALKALOIDS). Distinctive color reactions are obtained on adding sulphuric acid and ferric chloride. See "Proc. Am. Phar. Assoc." 1878. Howie (CURCUMA). 0.3 Gm. of the powdered rhubarb or insect powder to be tested are heaped upon filter-paper, 50 drops chloroform gradually dropped upon it, and after drying and removing the powder, a small piece of borax is placed upon the spot and a drop of HC1 added. The appearance of the well-known red color indicates curcuma. Maisch's test is similar. Hoyer (BERLIN-BLUE GELATIN MASS). Freshly precipitated Berlin blue is placed on a dialyzer with a little water, and the external water changed until the solut. begins to pass through the parchment. Then dilute the solut. and filter through paper. Next heat almost to boiling and add gradu- ally a warm, thin solut. of gelatin, until coagulation begins to set in; then strain through wetted flannel. Hoyer (CARMINE). Heat i Gm. on a sand-bath with i to 2 Cc. strong ammonia and 6 to 8 Cc. distilled water, until the excess of ammonia is driven off. When the solution becomes clear red, allow to cool, and filter off ppt. To the filtrate, which should be quite neutral, add 4 to 6 times its volume abso- lute alcohol, and collect the clear red ppt. which is thrown down. When required for use, dissolve this powder in water and add i to 2% chloral hydrate to make the solution permanent. Hoyer (CARMINE GELATIN MASS). Mix equal parts of cone, gel- atin solut. and neutral carmine as above, digest in a water-bath until the dark violet-red tint begins to change to bright red, then add 5 to 10% glycerin and at least 2% by weight chlo- ral hydrate in cone, solut. Filter through flannel and keep in an open vessel under a bell-glass. TESTS AND REAGENTS. 139 Hoyer (GOLD STAIN). A 0.5-% solut. of gold and potassium chloride is used instead of gold chloride only. Hoyer (LEAD-CHROMATE GELATIN MASS). Filter i volume 20-% gelatin solut., add i volume cold sat. potassium-bichro- mate solut., then warm almost to boiling and add gradually i volume cold sat. neutral lead-acetate solut., which has been previously warmed. Or, mix the lead-acetate solut. with part of the gelatin solut., mix the bichromate solut. with the remainder, heat the latter mixture, and gradually pour into it the first mixture, stirring continually. Hoyer (MOUNTING MEDIUM). Dissolve acacia in a cone, solut. of chloral hydrate containing 5- to 10% glycerin to form a thick syrupy fluid, which should subsequently be filtered through thick swansdown. This form of the medium answers with objects stained with carmine or hematoxylin, but if aniline stains be employed the gum should be dissolved in a 50-% solut. potassium acetate, or solut. ammonium acetate prepared by neutralizing 10 Gm. concent, ammonia with acetic acid and making up with water to 30 Gm. Hoyer (SHELLAC INJECTION MASS). Dissolve shellac in 8o-% alcohol to the consistency of a thin syrup, and strain through muslin of medium thickness. Color with aniline color in alco- holic solution, or by means of vermilion or other pigment sus- pended in alcohol. Hoyer (SILVER-NITRATE GELATIN MASS). Mix a cone, solut. of gelatin with an equal volume of a 4-% silver-nitrate solut. . and warm, then add a very small quantity of aqueous pyro- gallic-acid solut. to reduce the silver salt, and add chloral and glycerin as in the carmine gelatin mass. Hoyer (SILVER STAIN). Add ammonia to a solut. of silver nitrate of known strength, until the ppt. formed just re-dis- solves, then dilute the solut. until it contains 0.5 to 0.75% of the salt Huber (FREE MINERAL ACIDS). The reagent is an aqueous solut. containing 50% each of ammonium molybdate and potassium ferrocyanide. Mineral acids yield with reagent a red turbidity or brown precipitate, depending upon the quan- tity present. Boric and arsenous acids do not give this reaction. 140 TESTS AND REAGENTS. Huebl (IODINE NUMBER). This serves for the estimation of unsaturated compounds in a substance (oils, rosin, etc.), and depends upon the power of these compounds of forming iodine-compounds. The iodine number of a substance is the quantity of iodine which 100 parts of the substance will take up. Huebl (SOLUTION FOR TESTING OILS). The solut., which is that used in the "iodine absorption test," is thus prepared: Iodine, 25 Gm. is dissolved in 500 Cc. 95-% alcohol; mercuric chloride, 30 Gm., is dissolved in a similar quantity of alcohol, and the two solutions are mixed. The reagent is thus applied: About 0.25 to 0.5 Gm. of the oil are accurately weighed and dissolved in 10 Cc. chloroform in a 250-0. stoppered flask, and 25 Cc.' of the Huebl reagent is run in. At the same time a blank experiment under similar conditions, but without any oil, is started. After standing in the dark for not less than 4 hours (preferably over night), 20 Cc. of io-% potassium- iodide solut. are added to each, and 150 Cc. water. The un- combined iodine is then titrated with thiosulphate, the dif- ference between two flasks showing the amount of iodine absorbed. Huebl-Waller (IODINE SOLUTION). Similar to the above, but with addition of 25 Gm. hydrochloric acid, sp. gr. 1.19, to the mercuric-chloride solut.; this modified reagent is much more permanent than the original Huebl solution. Huefner (UREA). A recently prepared sodium-hypobromite solut., made by adding 25 Gm. bromine all at once to a cooled solution of 100 Gm. sodium hydrate in 250 Gm. of water, decomposes urea into carbonic acid and nitrogen, the former being absorbed by the caustic soda, while the latter is meas- ured in a suitable apparatus (Knop's azotometer, Esbach's ureometer), and the quantity of urea thus quantitatively estimated. Huehnefeld (BLOOD IN URINE). Acetic acid, 2, distilled water, i, are each mixed with alcohol, 100, and turpentine, 100; i Cc. of the mixture and i Cc. tincture guaiac are mixed together and 3 to 4 Cc. urine added; if blood present, a blue zone is formed. Huehnefeld (TURPENTINE SOLUTION FOR TESTING FOR BLOOD). Ten volumes each of oil turpentine, alcohol, and TESTS AND REAGENTS. 141 chloroform, are mixed with one volume glacial acetic acid, and then water added drop by drop so long as the liquid remains clear. The liquid to be tested for blood (urine) is mixed with a few drops reagent and a few drops tincture guaiac added a dark blue color of the silky mixture indicates blood. According to Schar, test is applied by adding to sus- pected liquid a i-% solut. of guaiac resin in absolute alcohol, and shaking resulting ppt., after nitration, with the Huehne- feld turpentine solution. Huizinga (GLUCOSE). Add caustic potassa, then ammonium molybdate (or tungstate), boil, and then add hydrochloric acid a blue color develops if glucose present. Humbert-Henry (IODINE; BROMINE). See Henry-Humbert. Hume (ARSENIC). A yellow ppt. forms on passing arseniuretted hydrogen into ammoniacal silver-nitrate solut. Hume (FREE MINERAL ACIDS). Free mineral acids in vinegar give distinctive color reactions when 2 drops vinegar are added to residue left on evaporating a neutral solut. of ammonium molybdate to dryness on platinum foil, heating till barely moist, and then cooling. Hummel (BUTTER). Press bit of butter to a thin film between cover-glass and glass slide, and examine with polarizing mi- croscope having a selenite plate between slide and lower nichol. Normal butters give uniformly blue-colored field with absence of fat crystals ; renovated butters give blue field mottled with yellow. Huppert (BILIARY PIGMENTS). Urine is treated with milk-of- lime or with calcium chloride and ammonia, whereby, in the presence of biliary pigments, a yellow ppt. of bilirubin-lime is formed. Hot alcohol, containing sulphuric acid, dissolves this, forming a green solution. After administration of senna or rhubarb, the ppt. with lime is of a rose-red color, the acidified alcoholic solut. being orange-yellow. Husemann (MORPHINE REACTION). Morphine is warmed with cone, sulphuric acid and, after cooling, treated with a drop of nitric acid a beautiful dark- violet color results, changing to a blood-red and gradually fading. Hyatt (SHELLAC METHOD FOR HARD, CHITINOUS OBJECTS). Soak in alcohol, then immerse in a clear, alcoholic solut, 142 TESTS AND REAGENTS. shellac for a day or two, then imbed with plenty thick shellac solut. in a groove in one-half of a soft-wood cylinder split in two for the purpose. Tie the two halves of the cylinder together, and when the shellac has become quite hard, fix the cylinder in a microtome, soak with warm water, and cut the sections. Hyde (THALLEIOQUIN REACTION). See Brand's test. Ide (IMBEDDING METHOD). Imbed object in collodion in a tube by Gilson's method, boil collodion for 40 minutes, next bring for 15 minutes into chloroform heated to 30 C. and contain- ing one-fourth part of paraffin, then place for 10 minutes in pure melted paraffin. Ihl-Pechmann (LEVULOSE). i. Warm substance with cone, alcoholic solut. resorcin containing a little hydrochloric acid a red color develops. 2. Add substance to a cone, solut. diphenylamine, then add hydrochloric acid, and boil a yel- lowish-green, then dark-blue color appears. Ilimow (ALBUMIN IN URINE). Cloudiness and a flocculent deposit appear on acidifying the urine, if necessary, with sodium acid phosphate, allowing to settle, cooling, and filter- ing, then adding diluted carbolic acid (i : 20). Israel (ORCEIN STAIN). Orcein, 2 Gm.; glacial acetic acid, 2 Gm,; distilled water, 100 Cc. After staining in this, wash object in distilled water, and pass rapidly through abso- lute alcohol to thick cedar oil, in which it should be mounted. Istrati (ALDEHYDES IN ALCOHOL). Add 0.2 Cc. of a satur. alcoholic solut. of a phenol to 2 Cc. of the alcohol to be exam- ined, then add i Cc. cone, sulphuric acid. Different phenols give various color reactions, for which see MERCK'S REPORT, ix, p. 23. Ittner (HYDROCYANIC-ACID REACTION). An alkali-cyanide solution when mixed with a solution of a ferroso-ferric salt, yields a p'/ecipitate of Prussian blue. Jack (SUGAR IN THE URINE). Phenylhydrazine forms with sugar a difficultly soluble osazone. See also Fischer's test. Jackson (TITANIUM). On adding hydrogen dioxide to a solut. of titanium in hydrochloric or sulphuric acid, a yellow to orange color develops. TESTS AND REAGENTS. 143 Jacob (FREEZING MASS). Acacia, 5 parts; tragacanth, i part; gelatin, i part; warm water containing one-sixth part of glyc- erin, enough to form a thin jelly when cold. Jacobsen (FATTY OILS.) Bring fatty oils in contact with rosani- line acetate, which is insoluble in neutral fats, but is dissolved by free fatty acids. Jacqemart (ETHYL AND METHYL ALCOHOLS). Upon heating ethyl alcohol with a solut. mercuric nitrate, the mercuric salt is reduced and a black ppt. results on adding ammonia. Methyl alcohol does not give this reaction. Jacquemin (ALKALIES AND ALKALOIDS). A solut. of pyrogallol containing ferric chloride is turned blue by alkalies or alkaloids. Jacquemin (ANILINE REACTION). A very dilute aqueous solu- tion of aniline treated with a chlorinated-lime solut. and then a few drops of a very dilute ammonium-sulphide solut., devel- ops a rose-red color even in dilutions of i : 250,000. Jacquemin (IODINE). Pyrogallol gives a brown color with io- dine. Jacquemin (NITROBENZENE). On adding solut. stannous chlo- ride in caustic soda, aniline is formed, and a blue color develops on adding carbolic acid and chlorinated-soda solut. Jacquemin (PHENOL REACTION). A little aniline and a few drops of a sodium-hypochlorite solut. cause a blue color, changed to a red upon the addition of acids, if a phenol is present. Jacquemin (WOOL, SILK AND COTTON). Wash textile fabric in warm dilute solut. chromic acid, then wash with water wool and silk are dyed ; cotton is not. Jaeger (GLYCERIN MEDIUM). Glycerin, i part; alcohol, i part; sea- water, 10 parts. Jaffe (CREATININE). Urine containing creatinine gives, with an aqueous solut. of picric acid and a few drops soda lye, a red color which becomes yellow on adding acid. See also WeyVs test. Jaffe (INDICAN IN URINE). Mix urine with equal volume cone. H 2 SO 4 , add a few Cc. chloroform, and then solut. chlorinated lime or Javelle water by drops, shaking after each addition the chloroform is gradually colored blue. Slight excess of I chlorinated lime does no harm, but large excess interferes with test. 144 TESTS AND REAGENTS. Jahr's test for determining the melting-point of butter. See Drouofs test. Jaillard (ROSE-GERANIUM OIL). Add 6 drops oil to 5 Cc. 70-% alcohol complete solut. should result. Jakimovitch (SILVER PROCESS). Stain dark-brown with silver stain, then expose to light for 5 to 7 days in a mixture of for- mic acid, i part; amyl alcohol, i part; and water, 100 parts. Renew mixture from time to time, and when all the mixture is dissolved a darker color is permanently assumed. Jakobsohn (STAIN FOR EPITHELIA IN URINE). Add a i-% solut. sodium-alizarin monosulphonate to i drop recently-cen- trifugated sediment. Thymol may be used for preservation of urine. Jaksch, Von- (BILIRUBIN IN BLOOD). Place blood in test-tube in refrigerator; after coagulation, withdraw serum into test- tube, and shake a yellow froth indicates bilirubin. Serum becomes green if placed in warm place for 3 or 4 hours. Jaksch, Von- (DIACETIC ACID IN URINE). Add solut. ferric chloride to urine, filter, then add more reagent, and boil portion of the mixture the red color should persist. To another por- tion of urine add sulphuric acid and ether, then apply ferric- chloride test to ethereal extract. Jaksch, Von- (MELANIN IN URINE). Add a few drops cone, ferric- chloride solut. melanin gives a gray reaction, andppt. formed is soluble in excess of reagent. Jaksch, Von- (PARA-CRESOL). Add sodium nitro-prussiate and caustic potassa to solut. a reddish-yellow develops, changed to light pink on addition of acetic acid. Jaksch, Von- (THALLINE). Shake urine with ether, and add fer- ric-chloride solut. to ethereal extract a dark-green color develops. Jaksch, Von- (SUGAR IN URINE). Free 50 Cc. urine from albu- min, add 2 Gm. sodium acetate and i or 2 Gm. phenylhydra- zine hydrochlorate, and heat to 100 C. on cooling, phenyl- glucosazone crystallizes out. Jaksch, Von- (URIC ACID). Modified murexid test, bromine or chlorine water or nitrous acid being used as oxidizer. James (SLIDE-CLEANING MIXTURE). Equal parts benzin, tur- pentine, and alcohol. TESTS AND REAGENTS. 145 Jandrier (COTTON IN WOOLEN FABRICS). Wash sample of fabric, and treat with sulphuric acid (20 Be.) for half hour on water-bath. To i or 2 Cc. of this solut. add o.oi Gm. resorcin, and overlay on cone, sulphuric acid free from nitrous products. Heat developed is sufficient to give a color at contact-point of the liquids, but intensity of color may be increased by slightly heating. If product resulting from treating cotton is made up to i : 1,000, resorcin will give an orange color; alpha- naphtol a purple; gallic acid a green, gradually becoming vio- let down in the acid; hydroquinone of pyrogallol a brown; morphine or codeine lavender; thymol or menthol a pink. Cotton may be detected in colored goods, using bone-black to decolorize solut. if necessary. Jansen (CARMINE BLUE). An acidified alcoholic solut. of Meis- ter, Lucius, and Briming's "bleu carmin aqueux." Jassoy (MORPHINE). Shake suspected powder with 20 times its weight of cold water, filter, add iodic acid and then chloroform the last is colored rose-red if morphine present. Javelle, Eau de (POTASSIUM-HYPOCHLORITE SOLUTION). Dis- solve 8 parts caustic potassa in 100 parts distilled water, and pass chlorine through to saturation, keeping the solution cool meanwhile with a mixture of ice and salt. Or, mix 20 parts chlorinated lime with 100 parts water and, after standing some time, add a solution of 15 parts of caustic potassa in 100 parts water. Filter after standing several hours and use filtrate. Should any lime be left in solution and form a pellicle of crys- talline calcium carbonate, remove by adding a few drops of potassa solution and filtering off the ppt. formed. Jaworowski (ALBUMIN AND PEPTONE IN URINE). Reagent is a solut. of ammonium molybdate and citric acid, 4, in water, 40. The urine is mixed with excess of soda and filtered, evap- orated to one-third, shaken out with amyl alcohol, -and neu- tralized with citric acid; on addition of reagent a precipitate forms if albumin or peptone present. Jaworowski (ALKALOIDS). Dissolve 0.3 Gm. sodium vanadate in 10 Cc. warm distilled water; dissolve 0.3 Gm. cupric sul- phate in 10 Cc. warm distilled water; mix the solutions, and add sufficient cone, acetic acid (7 to 8 drops) to dissolve ppt. of copper vanadate, and filter turbid liquid. In testing, sub- 146 TESTS AND REAGENTS. stance is dissolved in 4 or 5 Cc. water (pure alkaloids with aid of a few drops dil. acetic acid), and solut. divided into two portions, one of which is treated with reagent in the cold, the other treated with reagent after being heated. According to the alkaloid under consideration, a ppt. will form in one of the solutions. Some are not pptd., however. For details see MERCK'S REPORT, v, p. 456. Jaworowski (AMMONIA). Mercuric chloride, i; sodium car- bonate, i ; sodium chloride, i ; water, 30. Jaworowski (CHLORAL-HYDRATE REACTIONS), i. Dissolve 0.12 Gm. resorcin in aqueous solut. chloral hydrate, and over- lay solut. on dil. sulphuric acid a few colored rings appear, a brown one being most distinct; on shaking, mixture turns brown, being clear at first, then turbid. On superstratifying with cone, ammonia, the upper alkaline stratum becomes yel- lowish-red. 2. Nessler's solut. occasions in chloral-hydrate solutions a brick-red ppt. which gradually becomes brighter, , and finally dirty yellowish-green. 3. Add 0.3 Gm. potas- sium sulphocyanate to 2 Cc. chloral-hydrate solut. (contain- ing about 0.03 0.06 Gm.), heat to boiling, then add 3 to 5 drops potassa solut. mixture becomes light brown and de- posits a dark-brown ppt.; on adding ammonia solut. turns light brown, but not turbid. 4. Dissolve 0.02 or 0.03 Gm. sodium thiosulphate in 2 Cc. chloral-hydrate solut. (as before), and heat liquid assumes a brick-red color and becomes tur- bid; on adding a few drops potassa solut., mixture becomes a clear brownish-red. 5. Dissolve 0.06 to 0.12 Gm. phloro- glucin in 3 to 4 Cc. hot dist. water, add 0.09 to 0.12 Gm. chloral , hydrate, boil, then add 16 drops normal potassa solut. a deep brownish-red develops. If cooled liquid is acidulated with HC1 and shaken with amylic alcohol, latter becomes brown-red or deep brown. Chloroform yields under similar circum- stances (phloroglucin being dissolved in hot 90-% alcohol) a dirty-brown color in 2 to 4 hours. Jaworowski (CINCHONA ALKALOIDS). Freshly prepared mix- ture of equal parts io-% sodium-thiosulphate solut. and 5-% copper-sulphate solut. Quinine, cinchonine, cinchonidine, and quinidine all give yellow amorphous ppts. with reagent. TESTS AND REAGENTS. 147 Jaworowski (COPPER). Reagent prepared by adding i or 2 drops phenol to 5 Cc. ammonia water. Jaworowski (GLUCOSE). Add 0.12 Gm. iodic acid and 0.2 to 0.4 Gm. caustic-soda solut. to 3 or 4 Cc. glucose solut. and boil for i minute. On cooling, acidulate with dil. HC1, and carefully overlay with ammonia a dark ppt. of nitrogen iodide falls. Jean (OILS). Syrupy phosphoric acid, saturated with hydro- chloric acid gas, gives distinctive color reactions with various oils. Jean-Alvarez (CHLORATES, CHLORIDES AND NITRATES). Ppt. liquid with silver acetate and filter off silver chloride. Acid- ulate nitrate with acetic acid, and heat with piece of zinc; by this means chlorates are reduced to chlorides and pptd. as silver chloride. The ppt. gradually disappears, however, because of its further reduction to metallic silver. A portion of it is therefore made alkaline with potassa, and treated with Nessler's solut. a red ppt. indicates ammonia resulting from reduction of any nitrate that may have been present. Jehn (PEPPERMINT OIL). Dark, cherry-red color develops on adding chloral hydrate, and changed to violet on further addi- tion of sulphuric acid and chloroform. Johannson (ALKALOIDS AND PROXIMATE PRINCIPLES), i Gm. ammonium vanadate dissolved in 100 Cc. cone, sulphuric acid gives characteristic reactions, as follows; Aconitine light coffee-brown ; atropine red changing to yellowish-red and to red again; apomorphine violet-blue changing rapidly to dirty- green, then to reddish-brown; brucine intense blood- red, color fading then returning again; cinch nine faint orange; cocaine orange; code ; ne greenish-brown to brown; colckicine green, changing to brownish-green and coffee- brown; coniine intense green, becoming brownish; caffeine no reaction; digitalin intense dark brown; morphine brown; narceine brown to brownish, dirty blue- violet, be- coming red-brown; narcotine intense blood-red; papaverine violet, changing to dark reddish- violet, bluish-green, and orange-yellow ; picrotoxin intense yellowish-red pilocar- pine light orange; piperin intense red-brown to black- brown, particles being black; physostigmine greenish-yellow changing to carmine-red and yellowish-brown; quinidine 148 TESTS AND REAGENTS. faint bluish-green; quinine pale orange, then bluish-green to greenish-brown; antifebrin carmine-red changing to brown; antipyrine intense greenish-blue, becoming bluer; kairin dirty rose-red changing to dirty light-brown and brownish-green; santonin no reaction; solanine coffee- brown, the edges of the drops becoming carmine-red, yellow towards the center, and dirty-green at the center. In 2 hours the drop is gelatinous and intensely dark- violet ; strychnine bluish- violet, changing to reddish- violet, carmine-red, and fiery red. When crystals are simply moistened with rea- gent a violet blue develops; veratrine brownish-red chang- ing to dark reddish- violet. Johnson (ALBUMIN). See Hager's test for alkaloids. Johnson (ARSENIC). Heat with soda and a strip of aluminium arseniuretted hydrogen is evolved, detected by silver-nitrate paper. Johnson (CEMENT FOR FIXING CELLOIDIN BLOCKS). Melt to- gether i part beeswax and 2 parts resin. Drop a little on to the warmed object-holder, then press on to it the perfectly dry celloidin block, and allow to cool. Johnson (PLATINUM HARDENING MIXTURE). Mix solutions of 2.5-% potassium bichromate, 70 parts; 2-% osmic acid, 10 parts; and i-% platinic chloride, 15 parts, with 5 parts acetic or formic acid. Johnson (SUGAR IN URINE). Heat diabetic urine with picric- acid and potassa solut. a deep-red color appears. Author recommends the previous removal of uric and creatinine with mercuric chloride. From the filtrate obtained after a while, the excess of corrosive sublimate is precipitated with ammonia, and the solut. then tested with picric acid. Joliet (IMBEDDING METHOD). Dissolve acacia in water to the consistency of a thick syrup, and add 6 to 10 drops glycerin to a watch-glassful. Immerse object, and leave to dry for i to 4 days, then cut out a block containing it and allow the other side to dry. Jolles (ACETONE). Acetone is pptd. by phenvlhydrazine. Jolles (ALBUMIN IN URINE). Corrosive sublimate, i Gm.; suc- cinic acid, 2 Gm. ; sodium chloride, i Gm.; water, 50 Gm. To apply the test, 4.5 Cc. of the filtered urine are poured into TESTS AND REAGENTS. 149 each of two test-tubes, i Cc. acetic acid added to each, and then the mixtures shaken up, in one case with 4 Cc. of rea- gent, in the other with 4 Cc. distilled water. By comparing the samples, traces of albumin (1:120,000) may be detected. See Spiegler's reagent. Jolles (BILIARY PIGMENTS). Shake 50 Cc. urine for several minutes in a glass cylinder with a few drops io-% HC1, 5 Cc. pure chloroform, and a satur. barium-chloride solut. After standing 10 minutes, the chloroform together with the ppt, is removed with a pipette, and the chloroform evaporated off in a test-tube on a water-bath at 80 C. On exposure to or- dinary temperature for some time, the aqueous portion of the residue is decanted from the agglutinated precipitate. This latter is distinctly colored even when only i% bile is present in the urine; on adding 3 drops cone, nitric acid containing one-third its volume fuming nitric acid, the characteristic green and blue rings are formed. Jolles (IODINE IN URINE). Mix urine with an equal volume HC1 and a few drops chlorine water iodine, if present, causes a brown ring, becoming blue on adding starch solution. Jolles (MERCURY IN URINE). Warm 100 Cc. urine with 2 Gin. granulated gold and some stannous chloride. After decant- ing the liquid, wash any amalgam that may be formed with water, and then introduce into a test-tube with a little water and an equal volume of freshly prepared stannous-chloride solut. The slightest traces of mercury may also be quantita- tively estimated by heating the dried amalgam. See Merge? s test. Joly-Pacquelin (PYROPHOSPHORIC ACID IN URINE). On heat- ing urine with cone, acids or alkalies, pyrophosphates are changed to orthophosphates, which are then pptd. by ammo- nium molybdate. Jones (CHLORIDES, BROMIDES, AND IODIDES). Place substance in a large test-tube with a little manganese dioxide and water, and add i drop io-% sulphuric acid a brown color develops if iodine present and, on boiling, violet vapors are given off. When all iodine is removed by boiling, c urther addition of 2 Cc. of acid causes evolution of brown vapors on again boiling, if bromine be present. When all the bro- 150 TESTS AND REAGENTS. mine removed by boiling, cool, add equal volume of acid and heat once more. Green vapors indicate chlorine. Jorissen (AMYLIC ALCOHOL). 10 drops colorless aniline and 2 or 3 drops hydrochloric acid cause a red color in 10 Cc. alcohol if fusel oil present in quantity. Very small quantities of fusel oil must first be separated by shaking liquid with ether and evaporating ethereal layer before applying test. Reaction is not produced by the fusel oil contained in alcohol, but is due to the presence of furfurol, one of the fermentation by-pro- ducts (Forster). If considerable quantities of furfurol are present, the liquid may be tested directly with a few drops of aniline and hydrochloric acid. Jorissen (ALKALOIDS), i Gm. zinc chloride dissolved in 30 Gm. each of hydrochloric acid and water. Alkaloids evaporated to dryness with this solution give characteristic color reac- tions. See Hager, Pharm. Praxis, 1886, III, p. 1250. Jorissen (APIOL). Add chlorine water to dilute alcoholic solut. of apiol until slight turbidity, then add a few drops NH 3 a handsome red color develops, which soon fades. Color very intense with pure apiol, but weak with adulterated apiol. Jorissen (IODINE IN BROMINE). Boil with 30 Cc. saturated solut. potassium chlorate till colorless, cool, add a few drops morphine solution (i Gm. dissolved in excess of dil. H 2 SO 4 and water to make 100 Cc.) and a little chloroform latter is colored violet if iodine present. Jorissen (MINERAL ACIDS IN VINEGAR). A purple color devel- ops on adding vinegar containing mineral acids to a mixture of i drop Gurjun oil and 25 drops glacial acetic acid. Jorissen (MORPHINE). Heat morphine on a water-bath with a few drops cone. H 2 SO 4 and a crystal ferrous sulphate, and pour resulting liquid into a few Cc. ammonia water at point of contact a red color develops, soon changing to violet, while the ammonia solut. turns blue. Jorissen (NITROUS ACID). Dissolve o.oi Gm. fuchsine in 100 Cc. glacial acetic acid; on adding to 2 Cc. of this solution a trace of a nitrite, the color changes from violet to blue, then to dark green, yellowish-green, and reddish-yellow, and is finally entirely discharged. TESTS AND REAGENTS. 151 Jorissen (SALICYLIC ACID IN PRESENCE OF CITRIC ACID). Mix 10 Cc. liquid with 4 drops io-% solution potassium- or sodium nitrite, 4 drops of acetic acid, and i drop io-% solu- tion copper sulphate, and heat mixture to boiling-point if salicylic acid present a blood-red color develops. Joseph (INJECTION MASS). Dilute filtered white of egg with i- to 5-% carmine solution. This mass remains liquid when cold, but coagulates when immersed in dilute nitric, chromic, or osmic acid. Julius (BENZIDINE). A voluminous deep-blue ppt. forms on adding potassium bichromate to an aqueous solution. Jungmann (ALKALOIDS). Upon treating the ppts. obtained with phosphomolybdic acid (see Sonnenschein's reagent) with ammonia, several are colored blue or green. See Hager t Pharm. Praxis, 1886, I, p. 203. Jungmann (ARBUTIN). A blue color develops on making the solution alkaline and adding phosphomolybdic acid. Just (IRON IN FERRUGINOUS NUCLEINS AND NUCLEO-ALBU- MINS [HEMOGLOBIN, HEMATIN, etc.]). Add NH 3 to a strong solut. ammonium persulphate until decidedly alkaline, then add the ferruginous nuclein, and boil for 3 or 4 minutes. Make up NH 3 which escapes on boiling, and keep solut. alka- line. The solut. at first yellow, reddish-brown, or black, be- comes colorless on boiling, ferric hydroxide in flocculent form separating. Test may be carried out qualitatively or quan- titatively. Kaatzer (TUBERCLE STAIN). Place cover-glass preparation in supersat. alcoh. solut. gentian violet for 24 hrs., or, if solut. is warmed to 80 C., for 3 minutes. Decolorize in solut. of 100 Cc. 90-% alcohol, 20 Cc. water, and 20 drops cone. HC1. Wash in 90-% alcohol. After-stain with cone, aqueous solut. vesuvine. Kadyi (IMBEDDING MASS). Heat 25 Gm. sodium-stearate soap in shavings with 100 Cc. 96-% alcohol in a retort on a water- bath. When solution is complete, filter and cautiously add water in small quantities until a drop of solution, poured into a watch-glass, no longer solidifies into a white mass. About 5 to 10 Gm. water will be required for 120 Gm. soap solution. 152 TESTS 4ND REAGENTS. The finished mass should be almost transparent, with merely the slightest blue opalescence. Kaiser (BISMARCK-BROWN STAIN). Stain sections for 48 hours, at a temperature of 60 C., in a sat. solut. Bismarck brown in 6o-% alcohol, and wash out in 60- % alcohol containing 2% HC1 or 3% acetic acid. Kaiser (GLYCERIN JELLY). Soak i part, by weight, of gelatin in 6 parts water for about 2 hours, then add 7 parts glycerin, and for every 100 Gm. of the mixture i Gm. strong carbolic acid. Warm 10 to 15 minutes, stirring until all the flakes produced by the carbolic acid have disappeared, then filter through wet glass-wool. Kaiser (NERVE STAIN). Modification of Weigert's process. Harden material in M tiller's solution for 2 or 3 days, then cut into slices 2 to 4 Mm. thick and treat with solution for 5 or 6 days more. Subsequently immerse in Marchi's solution for 8 days, then wash, pass through alcohol, and imbed in celloidin. Mordant sections for 5 minutes in the following mixture: Solution ferric chloride, i part; distilled water, i part ; alcohol, 3 parts. Next wash in Weigert's hematoxylin, and warm in a fresh quantity of latter for a few minutes, wash with water, differentiate in Pal's solution, and neu- tralize oxalic acid by washing in water containing a little ammonia. Kaiser (STAIN FOR SPINAL CORD). Stain sections for a few hours in a solution of naphtylamine brown, i part; water, 200 parts; and alcohol, 100 parts. Afterwards, wash with alcohol and clear with origanum oil. Kaiser (Wooo CELLULOSE). The reagent is prepared by heat- ing on a water-bath at about 95 C. a mixture of equal vol- umes of furfurol-free amylic alcohol and cone. H 2 SO 4 , until a slight evolution of gas ensues, and then cooling the light red- dish-yellow mixture. The "amyl-sulphuric acid" so ob- tained possesses the property of coloring wood cellulose red, violet, or an intense indigo, according to the quantity present. For instance, on moistening a piece of newspaper, etc., with .the reagent, a greenish color first develops, becoming later on a fine blue. Pure Swedish filtering paper acquires only a red color; poor qualities, a violet. The reaction is facilitated by TESTS AND REAGENTS. 153 blowing a current of air upon the moistened spot, or by lightly warming. On washing with water the colors become lighter in color. The color reactions are due to the furol readily resulting from the action of amyl-sulphuric acid upon the wood-gum or xylose, from which the furol is formed by the simple splitting off of the elements of water. Kaiserling (PRESERVATION OF SPECIMENS). To preserve nat- ural color of specimens immerse latter for 3 to 5 days in a mix- ture of 200 Cc. formaldehyde, 1,000 Cc. water; 15 Gm. potas- sium nitrate, and 30 Gm. potassium acetate. Then remove and, after draining, place in 80- % alcohol for 6 hours, followed by 95-% alcohol for 2 hours, and permanently preserve in a dark place, in a mixture of 2,000 Cc. water, 200 potassium acetate, and 400 glycerin. Kalbrunner (MORPHINE). A blue color forms on adding 5 or 6 drops i : 8 aqueous ferric-chloride solution followed by 3 or 4 drops 1:120 potassium-ferricyanide solution. Kallins (NEUROLOGICAL METHOD). Hydroquinone, 5 Gm.; sodium sulphite, 40 Gm. ; potassium carbonate, 75 Gm.; dis- tilled water, 25 Cm. At time of using, dilute solut. with one- third to one-half its bulk absolute alcohol, and immerse sec- tions of silvered material for several minutes until reduction complete. Then place them in 70-% alcohol for 10 to 15 minutes, and subsequently leave in i : 5 aqueous solution so- dium thiosulphate for 24 hours or more. Finally, dehydrate and mount. Carmine may be used as an after-stain Kammerer (NITROUS AND NITRIC ACIDS). A blue color on add- ing potassium iodide, starch paste, and acetic acid indicates nitrous acid ; if blue color only produced on replacing the acetic acid with sulphuric acid and zinc dust, it indicates nitric acid. Karle. See Wiederholt. Kassner (HYDROGEN DIOXIDE). Upon adding potassium ferricyanide and some caustic-potassa solution, oxygen is evolved. Kastenbine (BLOOD STAINS). Moisten spot with water, and apply a piece of white blotting paper, with pressure; then touch spot on blotting paper with tincture guaiac and hydro- gen dioxide spot becomes deep blue if blood was present. Kauder (GLOBULIN). See PokTs test. 154 TESTS AND REAGENTS. Kayser (SACCHARIN). Shake out substance to be tested with a mixture of ether and benzin, evaporate ethereal extract, and test residue for sweetness. Keiser (MICRO - PRESERVATIVE SOLUTION). Corrosive sub- limate, 50 Gm. ; water, 300 Gm. ; acetic acid, 3 Gm. Keiser (SUBLIMATE SOLUTION). Mercuric chloride, 10 Gm.; glacial acetic acid, 3 Gm. ; distilled water, 300 Gm. Keller (CORNUTINE). Dissolve ergotin 0.5 Cc. in 0.5 Cc. water, and after adding one drop ammonia shake out with i Cc. ether; dissolve residue left on evaporating ethereal layer in 1.5 Gm. acetic acid containing a trace ferric chloride. Over- lay solution on a little cone. H 2 SO 4 in a test-tube; cornutine gives a bright bluish- violet color reaction at zone of contact. Keller (DIGITALIS PRINCIPLES). Dissolve substance in 3 to 4 Cc. glacial acetic acid, add a drop diluted ferric-chloride solut. and overlay on cone. H 2 SO 4 digitonin yields a rose-red, rap- idly-fading zone; digitalin a permanent, carmine-red zone; digitalein a rapidly-fading red zone; digitoocin first yields a dirty, brownish-green zone, then the upper portion of the sul- phuric acid is colored brownish-red, and above this a bluish- green band forms. Keller (ERGOTININE IN ERGOT). Shake powd. ergot with ether, let stand 15 minutes, and filter; to filtrate add about 10 drops hydrochlorated ether (5 Cc. cone. HC1 and 100 Cc. ether shaken together and decanted) ergotinine hydrochlorate is pptd. as yellow flakes. Collect ppt. on filter, wash with ether, and dis- solve in 2 Cc. glacial acetic acid; overlay solut. on cone. H 2 SO 4 and add a very little ferric-chloride solut. a blue color develops. Keller-Kiliani (DIGITALIS). Overlay a preparation of digitalis made with acetic acid and containing ferrous sulphate on H 2 S0 4 , also containing ferrous sulphate a reddish- violet develops. Kern (GOLD). A reddish-orange color and ppt. form on adding i drop gold-chloride solut. to a large excess of potassium- sulphocyanate solut. Kern (URANIUM). A brown ppt. soluble in HC1 forms on adding potassium-ferrocyanide solut.; the acid solut. turns green on boiling with a few drops HNO 3 . TESTS AND REAGENTS. 155 Kerner (CREATIN AND CREATININE). Creatinine is pptd. from acid solutions by phosphotungstic or phosphomolybdic acid; a crystalline ppt. is obtained from even very dilute solutions. The compound of creatin with the acids, however, is soluble, and may be obtained in crystalline form. Kerner (QUININE). Quinine sulphate is much more difficultly soluble in water than are the sulphates of the allied alkaloids. If therefore quinine sulphate (or any other quinine salt after addition of sodium sulphate) is shaken with a definite quan- tity of water, the volume of ammonia required to produce a permanent precipitate in the filtrate will be a measure of the percentage of allied alkaloids present. Digest 2 Gm. pure quinine sulphate in 20 Cc.water at 60 to 65 C. for an hour, and allow to stand for 2 hours at 15 C., occasionally shaking, and then filter through glass-wool; 5 Cc. of the filtrate require 4 to 4.3 Cc. of io-% ammonia. In the presence of cincho- nine, quinidine, etc., more ammonia is necessary. Kerner (QUININE IN URINE). Test depends on fluorescence of quinine solutions. Since this is prevented by sodium chlo- ride, a cone, mercurous-chloride solut. is added to the urine until a ppt. is no longer produced. On filtering, appreciable quantities of quinine indicated by fluorescence, and more easily so by the use of a fluoroscope. Kerstal (TELLURIUM). A violet color develops on shaking powdered ore containing tellurium with a little water and mercury, and then adding a little sodium amalgam. Kersting (NITRIC ACID). A few drops solut. of brucine in sul- phuric acid causes a brilliant red to yellowish-green color. Keutmann (SALOPHEN). Moisten 0.2 Gm. salophen with few drops nitrosylsulphuric acid (5 Gm. potassium nitrite and 100 Gm. sulphuric acid) the mass immediately becomes reddish- brown. On adding a few Cc. alcohol, color disappears; excess of alkali now added causes a yellow color, dissipated by excess of acid. Kieffer (FREE MINERAL ACIDS). Cautiously treat copper- sulphate solut. with ammonia until ppt. is just redissolved. Solutions of neutral metallic salts that show an acid reaction toward litmus produce a turbidity with this reagent ; if, how- ever, the salts contain free acids, the mixture remains clear. 156 TESTS AND REAGENTS. Kieffer (MORPHINE). On mixing 5 or 6 drops of a i: 8 ferric- chloride solut. and 3 drops of a i : 100 potassium-ferricyanide solut., a drop of morphine solut. will cause a blue color or pre- cipitate (reduction of the ferricyanide); Kintschgen-Gintl. See Milton's reagent. Kippenberger (ALKALOIDS). Iodine, 12.7 Gm.; potassium iodide, 60 Gm. ; water, one liter. The alkaloid may be liber- ated from the ppt. by dissolving the iodine compound in a little acetone, saturating first with alkali, then with acid, diluting with water and driving off acetone with heat; addition of a little thiosulphate solut. removes any traces of free iodine; the solut. is then made alkaline with sodium carbonate, and shaken out with ether or chloroform. Glucosides give no ppts. with this reagent. Kirkby (ALKALINE GLYCERIN MOUNTANT). A mixture of glyc- erin, 4; distilled water, 3; and solut. of potassa, B.P., i, makes a serviceable extemporaneous mountant for plant sec- tions. It combines the refringent property of the glycerin with the clearing action of the caustic potassa, and the swell- ing action of the latter is considerably restrained. Kirkby (CLEARING SECTIONS). Place sections in a fresh, clear solut. chlorinated lime until quite bleached (2 to 5 minutes), then gently warm in a test-tube for a few seconds, and after- wards quickly replace solut. with distilled water and boil for 2 or 3 minutes. Repeat the treatment with boiling water three times, after which wash with i-% acetic acid and finally with cold distilled water. Staining can then be performed. Kitasato-Salkowski (!NDOL IN BACTERIAL CULTURES). Po- tassium-nitrate solut. (i: 5,000), i Cc. and a little H 2 SO 4 are added to 10 Cc. of the culture broth. Indol is indicated by the formation of a red color. If the color reaction is given on adding H 2 SO 4 alone, it indicates presence of both indol and nitrites (red cholera reaction). Kitton (ASPHALT VARNISH). Dissolve asphalt in benzene and add a little gold size. Kitton (WHITE-LEAD CEMENT). Grind together equal parts powdered white lead, red lead, and litharge with a little tur- pentine, and when thoroughly incorporated, mix with gold TESTS AND REAGENTS. 157 size. Keep a stock of the materials ready ground, and mix as required for use. Kjeldahl (DETERMINING NITROGEN). Weigh 0.5 to 2 Gm. of the substance and boil with 20 Cc. H 2 SO 4 and 0.7 Gm. mer- curic oxide for 10 minutes, then add 10 Gm. potassium sul- phate, and continue boiling until solut. is a pale straw color. Cool, wash into a distilling flask with 200 Cc. water, and rinse out acid flask with two more successive lots of water. Add 75 Cc. of 50-% sodium-hydrate solut. and 10 Cc. potassium- sulphide solut., distil into 50 Cc. decinormal H 2 SO 4 , using cochineal as indicator. When all the ammonia has distilled over, titrate the uncombined acid. Each Cc. decinormal H 2 SO 4 used = 0.0014 N, =0.0017 NH 3 , =0.00886 albuminoids. In many cases the mercuric oxide is not necessary, and in that case the potassium sulphide is omitted. Kleb (GLYCERIN GELATIN). Wash 10 parts best French gela- tin and allow to stand in distilled water till it swells up ; then pour off excess of water, melt at a gentle heat, and add 10 parts glycerin and 2% carbolic acid. Kleb (GLYCERIN JELLY). Mix a cone, solut. isinglass with half its volume glycerin. Klein (COCHINEAL FLUID). See Csokor's alum cochineal. Klein (FIXING MIXTURE). Mix 2 parts 1:600 chromic-acid solut. with i part methylated spirit. Or, mix i Cc. io-% chromic-acid solut. with 60 Cc. water, and add 30 Cc. 90-% alcohol. Klein (MINERALS). For mechanical separation of constituents of a powdered mineral, an aqueous solut. cadmium borotung- state, sp. gr. 3.3, is used. See Thoulet's solution. Kleinenberg (COLOPHONY). A solut. of ordinary pale resin in rectified oil turpentine. Kleinenberg (HEMATOXYLIN). Great differences exist in the formulas for this stain. According to Squire, 20 Gm. of crys- tallized calcium chloride should be dissolved in 10 Cc. dis- tilled water, and 3 Gm. alum in 16 Cc. distilled water, by the aid of heat. Mix solutions and immediately dilute with 240 Cc. rectified spirit; filter after standing an hour, and add 2.5 Gm. hematoxylin. 158 TESTS AND REAGEHTS. Kleinenberg (PicRO-SuLPHURic ACID), i. Distilled water, 100 volumes; H 2 SO 4 2 volumes; dissolve in the mixture 0.25% picric acid. Dilute finished solution with three times its volume water. 2. 20 Cc. of saturated solut. picric acid, 380 Cc. distilled water, and 2 Cc. H 2 SO 4 . 3. Picric acid, i Gm. ; water, 100 C. ; sulphuric acid, 6 Cc. Klemperer (ZYMOGEN OF RENNET). To 2 Cc. filtered gastric juice add 10 Cc. milk, 2 Cc. 3-% solut. calcium chloride, and an excess of i-% solut. sodium carbonate, then place mixture in incubator milk is coagulated. Klett (INDICAN IN URINE). Add 5 Cc. 25-% HC1 and a crystal of ammonium persulphate to 10 Cc. urine, and shake whole with a little chloroform latter is colored blue if any indican is present. Kletzinski (QUININE). Add to a sat. solut. potassium ferri- cyanide five times its volume sat. potassium-chloride solut., make the blackish-green liquid strongly alkaline with ammo- nia, and filter. A blood-red to violet color is produced on add- ing an excess chlorine water to a liquid containing quinine, and then adding the above reagent. Klunge (BERBERINE). A red color forms on adding chlorine water to an aqueous solut. acidified with HC1 or H 2 SO 4 . Klunge (CUPRALOIN REACTION). A very dilute solut. of aloes is colored yellow on adding copper sulphate. On adding sodium chloride and gently warming, a red color results. On adding alcohol in addition to sodium chloride, color is pro- duced at ordinary temperature. Klunge (PHENOL). A blue color develops on adding a few drops of oxaniline solution, followed by a little ammonia. Knapp (GLUCOSE). Solut. of 10 Gm. mercuric cyanide and 100 Cc. soda-lye (sp. gr. 1.45) in enough water to make a liter. This solut. is reduced upon warming with glucose, metallic mercury precipitating. Creatin and creatinine act similarly. 40 Cc. solut. correspond to o.i Gm. glucose. Knauer (SLIDE-CLEANING PROCESS). Boil for 20 or 30 min- utes in io-% lysol solution, then rinse with water till clear. Knop (NITROGEN ESTIMATION). Reagent for estimation of nitrogen in ammonium salts and in amides by means of the azotometer is sodium hypobromite. See Huefner's test. TESTS AND REAGENTS. 159 Kobell (BISMUTH). A scarlet-red color develops when bismuth, mixed with an equal weight potassium iodide and a little sul- phur, is heated on charcoal in the blow-pipe flame. Kobell (MOLYBDIC ACID). A blue color forms on heating with H 2 SO 4 and adding alcohol. Kobert (HEMOGLOBIN). Solutions containing hemoglobin give a ppt. of zinc-hemoglobin on being shaken with zinc dust, or mixed with soluble zinc salts. The ppt. is colored red by alkalies. Kobert (MORPHINE, DIONIN, CODEINE, HEROIN, AND PERONIN). Treat substance with recently prepared formaldehyde-sul- phuric acid (2 or 3 drops formaldehyde and 3 Cc. sulphuric acid). Reactions are as follows: Morphine an immediate purple-red changing to violet, bluish- violet, then pure blue; dionin immediate deep-blue, unchanged; codeine reddish- violet, then bluish- violet ; heroin reddish- violet at first, then rapidly bluish- violet ; peronin reddish- violet persistent for many hours. Koch (ANILINE WATER). See Ehrlich-Weigert-Koch's test. Koch (BACTERIA STAIN). Place for 5 minutes in a solut. of K 2 CO 3 (prepared by mixing a sat. solut. of the salt with an equal quantity distilled water). Then dehydrate in alcohol, place in cedar-oil, and finally mount in balsam. Koch (CHOLERA REACTION). The addition of H 2 SO 4 to cholera cultures (on peptone) causes a red coloration, due to action of the acid on the two decomposition products of the cholera bacillus, indol and nitrous acid. Koch (COPAL METHOD). Stain small pieces of material in bulk and dehydrate with alcohol, then immerse in a thin solut. of copal in chloroform. Evaporate with a gentle heat until the solut. is so far concentrated as to draw out into threads that are brittle on cooling. Then remove objects and leave on a tile for a few days to dry. Sections may then be cut by means of a fine saw. If objects are imbedded unstained, remove copal from sections by soaking in chloroform, decalcify if nec- essary, and then stain. Koch (METHYL- VIOLET SOLUTION). Solut. for staining bac- teria is made by adding a few drops cone, methyl-violet solut. in absolute alcohol, to 20 Gm. distilled water. 160 TESTS AND REAGENTS. Koch (STAINING FLAGELLA). Immerse cover-glass prepara- tions in a i-% aqueous solut. hematoxylin, then transfer to a 5-% solut. chromic acid or to Muller's fluid; dry and mount in balsam. Koch (METHOD FOR TUBERCLE BACILLI). Place sections or cover-glass preparations in Koch's met hylene- blue solut. for 20 to 24 hours (or 0.5 to i hour if warmed to 40 C.), then treat with aqueous solut. vesuvine for 2 minutes, and wash out excess of color with distilled water. Cover-glass preparations should then be dried and mounted in balsam, whilst sections require to be dehydrated in absolute alcohol and cleared in cedar oil before mounting in balsam. Koch (METHYLENE-BLUE SOLUTION), i Cc. sat. alcoholic solut. met hylene blue; 0.2 Cc. io-% caustic potassa solut.; 200 Cc. distilled water. Koch (TUBERCLE BACILLI STAIN). 2 Cc. aniline are shaken with 20 Cc. water and the mixture filtered through a wetted filter. To the clear filtrate, alcoholic fuchsine- (or gentian- violet) solut. is added until a film having a metallic luster indicates saturation. Koch-Ehrlich (STAINING METHOD). Place sections or cover-glass preparations for at least 1 2 hours in gentian- violet or fuchsine aniline water (aniline water, 100 Cc.; cone, alcoholic solut. gentian violet or fuchsine, n Cc.; absolute alcohol, 10 Cc.), then immerse in a mixture of pure HNO 3 (sp. gr. 1.42), 10 Cc., and distilled water; 30 Cc., for some seconds. Rinse in 6o-% alcohol for a few minutes, and then counter-stain with vesu- vine (vesuvine, 0.5 Gm.; rectified spirit, 20 Cc.; distilled water, 80 Cc.) after gentian violet, or methylene blue (methyl- ene blue, 0.25 Gm.; rectified spirit, 20 Cc.; distilled water, 80 Cc.) after fuchsine. Finally rinse in water, dehydrate, clear, and mount in balsam. According to Squire, who points out that nitric acid is apt to injure delicate sections, Watson Cheyne recommends that sections be transferred from fuchsine- aniline water to distilled water, then rinsed in alcohol, and placed in the following contrast stain for i to 2 hours: Sat. jilcoholic solut. methylene blue, 20 Cc.; distilled water, 100 Cc.; formic acid (sp. gr. 1.2), i Cc. TESTS AND REAGENTS. 161 Koch-Ehrlich (TUBERCLE STAIN). Dry and fix cover-glass preparations in air, stain for 12 hours in Weigert-Koch aniline- water aniline-stain solut., then dip for i to 3 seconds in weak H 2 SO 4 (i : 3 or 4), and at once agitate in 60- % alcohol. After- stain in aqueous solut. vesuvine or methylene blue for several minutes. Koettstorfer (IODINE). On adding carbon disulphide, acidi- fying with diluted H 2 SO 4 and passing vapors of fuming nitric acid through the solut., a rose-red to violet color develops. Koettstorfer (NUMBER). This indicates the caustic potassa, in milligrammes, required to completely saponify one gramme of a fat. Kohler (ALKALOIDS). Distinctive color reactions are afforded on mixing alkaloids with 3 to 5 times their weight of potassium nitrate, then adding i or 2 drops H 2 SO 4 and sodium-hydrate solution. See Langley's test. Kolisch (CREATININE). Precipitant consists of mercuric chlo- ride, 30; sodium acetate, i; absolute alcohol, 125 Gm. ; acetic acid, 3 drops. Kollmann (FIXING SOLUTION). This contains 5% potassium bichromate, 2% chromic acid, and 2% cone. HNO 3 . Kolossow (GOLD METHOD). Impregnate objects for 2 or 3 hours with a i-% solut. gold chloride acidulated with i% HC1; subsequently reduce for 2 or 3 days, in the dark, in a o.oi- to 0.02-% solut. chromic acid. Kolossow (OSMIUM STAINS), i. A 0.5-% solut. osmium in a 2- or 3-% solut. uranium nitrate or acetate. 2. Absolute al- cohol, 50 Cc.; distilled water, 50 Cc.; cone, nitric acid, 2 Cc.; osmium, i to 2 Gm. Keep in a cool place. Partly reduced solutions may be regenerated by the addition of a little pow- dered potassa alum. Kolter (HYPOCHLOROUS ACID). On shaking the liquid to be tested with metallic mercury, brown oxy chloride of mercury forms in the presence of this acid. Koninck, De- (POTASSIUM). A yellow ppt. forms on adding a io-% solut. sodium nitrite mixed with cobalt chloride and acetic acid. 162 TESTS AND REAGENTS. Kopp (LEAD IN TIN-FOIL). A drop of H 2 SO 4 is applied to the foil; if pure tin, the spot remains white. If lead present, a black stain is produced. Kopp (NITRIC ACID). Add a little cone. H 2 SO 4 to a few crys- tals of diphenylamine, and then a little water; finally dilute solution with more cone. H 2 SO 4 . 0.5 Gm. of reagent is put on a watch-glass, and a drop of the fluid to be examined is al- lowed to fall in the middle the presence of HNO 3 is indicated by the appearance of a blue circle; numerous other bodies, such as sulphurous acid, hypochlorites, and ferrous salts, give a similar color. Diphenylamine-sulphate solution is also known as Pallet's reagent. Kopp (NITROUS ACID). A blue color forms on adding diphenyl- amine dissolved in H 2 SO 4 . Kopp (OLIVE OIL). This is the "elaidin" test, i volume of HNO 3 and a piece of copper wire being heated with 10 vol- umes of the oil. Kopsch (FORMALDEHYDE SOLUTION). Mix 4 parts 3.5-% bichro- mate solution and i part of commercial formaldehyde solu- tion. Korotneff (NARCOTIZATION METHOD). When Siphonophora are extended in water, a watch-glass containing chloroform is floated on the surface, and as soon as the animals are rendered insensible they are killed by means of hot mercuric choride or chromic-acid solut. Kossel (HYPOXANTHIN). Solution to be examined is treated with zinc and HC1, then made alkaline; hypoxanthin is indi- cated by a ruby-red color, changing to brown. Kossinski (DOUBLE STAINS), i. Stain sections for 10 to 20 minutes in sat. aqueous solut. indigo carmine, wash with water,, then with alcohol; next stain with 0.5-% solut. safra- nine in dilute alcohol, dehydrate and mount. 2. Stain for 3 to 5 minutes in o.i-% aqueous solut. nigrosin, and proceed as before. Kost (FREE HYDROCHLORIC ACID IN GASTRIC JUICE). io-% solut. tannin and solut. methyl violet are added to gastric juice color changes from violet to blue or green. Modifica- tion of Maly's test. TESTS AND REAGENTS. 163 Kotzebue (MORPHINE AND THALLINE). A io-% solut. phos- phomolybdic acid in ammonia-free water. 2 drops reagent yield with morphine (i part in 1,000,000 even) a delicate, yellowish- white ppt. On adding 30 min. strong ammonia a decided blue color develops, best seen by looking down liquid against white paper. Thalline behaves similarly, but reac- tion still more delicate (i : 2,000,000 almost). Kowarsky (SUGAR IN URINE). Shake together 5 drops pure phenylhydrazine, 10 drops glacial acetic acid, and i Cc. satur. sodium-chloride solut., then add 3 Cc. urine, and heat 2 min- utes, then allow to cool slowly if more than 0.5-% sugar present, ppt. of glucosazone forms in about 2 minutes. Small quantity of albumin does not interfere with reaction. Kraemer (ACETONE). See Messinger's test. Krant (ALKALOIDS). See Dragendorff's test. Krasser (ALBUMIN). Alcoholic solut. alloxan gives a bright-red color with albumin. JCrehbiel (BILIARY PIGMENTS). Mix urine to be tested with one-fourth its volume HC1 and add chlorinated-lime solut. drop by drop in the presence of biliary pigments a green color forms. Bromine water gives similar reactions. This is also known as Trousseau-Dumontpallier's reaction. Kremers-Schreiner (CEDAR-WOOD OIL IN SPEARMINT OIL). Treat oil with hydroxylamine, expel volatile matter with steam, and dry and weigh the carvoxime formed, from which determine carvone percentage present in oil (should be 56% for pure oil). Kronecker (ARTIFICIAL SERUM). Dissolve 6 Gm. of common salt and 0.06 Gm. caustic soda in 1000 Gm. distilled water. Kronig (CEMENT). Gradually add ordinary resin, 7 to 9 parts, to melted beeswax, 2 parts, then filter and cool. Kroupa (AMMONIA). Filter-paper dried after immersion in yel- low solut. of fuchsine in acidulated water becomes red when exposed to ammoniacal vapor. Krueger (GLUCOSE). See Boettger's test. Kriiger (INDICATOR). Fluorescein. Gives with alkalies a green fluorescence, discharged by acids. Krutwig (SILVER IN LEAD ORE). Dissolve ore in HN0 3 , add excess of soda, and examine gold-colored ppt. for silver. 1 64 TESTS AND REAGENTS. Kubel (COLCHICINE). Dissolve substance in cone. HNO 3 , and add water to brownish- violet solut. color changes to yellow; on now making alkaline with potassa, an orange-yellow or orange-red develops. Kubli (CARBON-DIOXIDE TEST FOR QUININE). Quinine is pptd. from a sat. solut. by sodium carbonate. Ppt. is dis- solved on addition of sodium bicarbonate. Carbonic acid gas is then introduced, and quinine carbonate precipitated. Carefully conducted, the result indicates purity of the quinine salt under examination. Kubli (WATER TEST FOR QUININE). Test is based on solubility of hydrated quinine, obtained by precipitating alkaloid with soda and observing quantity of water necessary to dissolve alkaloid pptd. The associated cinchona alkaloids are less soluble in water than quinine, consequently in their presence more solvent is required to produce a solution. Kuborne (ATROPINE: COCAINE). Treat substance in a porcelain evaporating dish with few drops HNO 3 , and evaporate to dry- ness on sand-bath. The cooled residue when heated on sand- bath with few drops solut. potassa in ethylic or preferably amylic alcohol, develops a fine violet color with cocaine; with atropine the color develops in the cold. Kuehne (ANILINE- AND CLOVE-OIL STAINS). Rub up as much methylene blue, safranine, methyl green, auramine, acid violet, or fluorescin, as will be held on the point of a knife-blade, with 10 Gm. clarified aniline, or with 15 Gm. clove oil. If not en- tirely dissolved, pour unfiltered into a flask and allow to settle. Remove several drops of clear liquid, and add to sufficient pure oil or aniline to yield the concentration desired. Kuehne (ANILINE SOLUTIONS). Rub up as much methylene blue, methyl green, or safranine as will go upon the point of a knife, with 10 Cc. aniline, and allow to settle. Kuehne (ANISEED-OIL FREEZING MASS). Soak objects in ani- seed oil for 12 to 24 hours, freeze and cut, then remove the oil with alcohol. Kuehne (BACTERIA STAIN: DRY METHOD). Stain in i-% aq. solut. ammonium carbonate to which has been added aq. solut. methylene blue, for 10 to 15 min. Rinse in water, de- colorize in i- to 2-% HC1, wash in water, dry on object-glass TESTS AND REAGENTS. 165 by a current of air produced by a bellows, treat with xylene, and mount in balsam. Kuehne (CARBOLIC FUCHSINE OR BLACK-BROWN). Dissolve i Gm. fuchsine or black-brown in 10 Cc. absolute alcohol, and add 100 Cc. 5-% aqueous solut. carbolic acid. Kuehne (CARBOLIC METHYLENE BLUE). Rub 1.5 Gm. methyl- ene blue with 10 Cc. absolute alcohol, and add 100 Cc. 5-% aqueous solut. carbolic acid. Kuehne (CARBOL-METHYLENE-BLUE BACTERIA STAIN). Stain in carbol-methylene blue to 2 hrs., rinse in water, extract in acidulated water (10 drops HC1 and 100 drops water). Rinse in weak aq. solut. lithium carbonate (10 drops water and 6 to 8 drops sat. solut. lithium carbonate), then in pure water; dip in absolute alcohol containing a small quantity methylene blue, then in methylene-blue aniline a few minutes. Clear in pure aniline, then in oil cloves 2 minutes. Extract oil with xylene, and mount in balsam. Kuehne (FLUORESCIN-OIL-CLOVE BACTERIA STAIN). Soak sec- tions in cone. aq. solut. oxalic acid 5 to 10 minutes, rinse in water, and dehydrate in alcohol. Stain in fuchsine-aniline water or methylene-blue in 0.5- to i-% aq. solut. ammonium carbonate. Dehydrate in alcohol containing small quantity of fuchsine or methylene blue, for 5 to 10 minutes. Then treat with ethereal oil, then with xylene, and finally mount in balsam. Kuehne (FUCHSINE BACTERIA STAIN). Stain in carbol-fuchsine 3 to 5 minutes Rinse in water, and dip in alcohol. To differen- tiate and decolorize, place in methylene-green aniline from 15 minutes to 2 hrs. , according to thickness of section. Then treat with an ethereal oil, then with xylene, and mount in balsam. Kuehne (IODINE-POTASSIUM IODIDE). Iodine, 2 Gm.; potas- sium iodide, 4 Gm.; distilled water, 100 Gm. Kuehne (MACERATING MIXTURE). Mix potassium chlorate with 4 times its quantity of HNO 3 . Kuehne (METHOD FOR BACTERIA). Sections are dehyhrated in alcohol, stained for 3 to 5 minutes with Kuehne 's carbolic fuch- sine, rinsed in water, dipped for i minute into alcohol, and extracted in Kuehne 's methyl-green aniline, then passed through terebene and xylene. Anthrax sections are stained for 5 minutes in carbolic black-brown, rinsed in a mixture of 166 TESTS AND REAGENTS. aqueous solution of lithium carbonate i Cc., and water 30 Cc.,. and then in 90-% alcohol. Afterwards place for 5 minutes in carbolic fuchsine, and decolorize in solut. yellow fluorescine,. iGm.,in absolute alcohol, 50 Cc. Tubercle sections are treated for 10 minutes with carbolic fuchsine, thoroughly rinsed in water, decolorized in fluorescine alcohol, and then transferred to terebene, xylene, and balsam. Or, before mounting, they may be counter-stained by treatment for 5 or 10 minutes with methyl-green aniline diluted with half its- bulk of aniline; then pass into terebene for 2 minutes, after- wards into xylene, and in balsam. Kuehne (METHYL-VIOLET SOLUTION). Dissolve i Gm. methyl- violet in 90 Cc. distilled water and 100 Cc. alcohol. Kuehne (METHYLENE-BLUE METHOD). Transfer sections from alcohol to carbolic methylene blue, and leave for half an hour, then rinse in water, and place in weakly acidulated water until of a pale-blue color. Next rinse in a mixture of sat. aqueous solut. lithium carbonate i Cc. and water 30 Cc., and transfer- to pure water. Afterwards dip one by one into absolute alco- hol in which some methylene blue has been dissolved, then transfer to Kuehne 's aniline solution of methylene blue to dehydrate, rinse in aniline, clear in terebene, then in xylene,. and mount in balsam. To show satisfactorily the structure of the tissue, Kuehne decolorizes sections stained in carbolic methylene blue with a solut. acetine- or chlorhydrin blue, 10- Gm., in 100 Cc. of io-% alcohol. This takes 10 to 60 minutes. They are then passed through alcohol, aniline, terebene, and xylene, after which they are double-stained by treatment for 2 'to 10 minutes with Kuehne's safranine aniline diluted to 4 or 5 times its bulk with aniline. Again pass through terebene- and xylene before mounting. Kuehne (MODIFIED GRAM'S METHOD). Stain nuclei with carmine, then treat sections for 5 minutes in methyl- violet solut. diluted one-sixth with a i-% aqueous solut. ammonium carbonate, or in a solut. Victoria blue, 0.25 Gm., in alcohol, 20 Cc., and distilled water, 80 Cc. Next rinse thoroughly in water and' transfer to Gram's solut. for 2 to 3 minutes ; again rinse in water and extract excess of stain with solut. yellow fluorescine, i Gm., in absolute alcohol, 50 Cc. Finally, pass through TESTS AND REAGENTS. 167 pure alcohol, aniline, terebene, and xylene, and mount in balsam. Kuehne (STAIN FOR TYPHOID AND CHOLERA BACILLUS). A cold saturated solution of methylene blue is mixed with i-% solution of ammonium carbonate. Preparations are im- mersed in the stain for 5 or 10 minutes, then well washed and placed in i-% HC1. Kuehne (SYNTONIN). Dissolve substance in lime water, and boil partial coagulation ensues (other acid-albumins and alkali-albumins remain in solution). Kuehne (TUBERCLE DOUBLE STAIN), a. Stain in carbolic- fuchsine 10 minutes, decolorize in 30-% HNO 3 , extract in 60- % alcohol until section is pink in color, wash in water, dehydrate in absol. alcohol 30 min., place for 5 to 10 min. in methylene- green aniline diluted with an equal vol. aniline, then in ethe- real oil 2 min., and in xylene, then mount in Canada balsam. 6. Stain in carbol-fuchsine 10 min., rinse in water, extract in fluorescin-alcohol a few minutes, double-stain in methylene- green aniline 5 min., place in ethereal oil, then in xylene, and then mount in Canada balsam. Kuehne (TUBERCLE TRIPLE STAIN), a. Weakly stain in Dela- field's hematoxylin solut., wash in water several seconds, dehydrate in alcohol, stain in carbol fuchsine 10 min.; rinse in water, extract fuchsine in fluorescine alcohol, rinse in pure alcohol, place in ethereal oil and in xylene, then in aura mine- aniline until stained yellowish; rinse in pure aniline, then treat with ethereal oil and xylene, and mount in Canada bal- sam, b. Stain section in nucleus black diluted 3 or 4 times with water, for several minutes, till section is dark grayish. Rinse in a weak aq. solut. lithium carbonate till section is light-gray, rinse in water, dehydrate in alcohol 5 min., stain in carbol-fuchsine 10 min., wash in water, extract in fluorescine- alcohol, wash in pure alcohol, place in methylene-green ani- line (not too cone.) for 5 to 10 minutes, then in ethereal oil and in xylene, and mount in balsam. Bacillus, red; nuclei, vessels, and protoplasm, of different tones of bluish-green. Kuelz (BILIARY ACIDS). Add i drop very dilute solut. cane sugar to biliary acid, then i drop cone. H,SO 4 a violet color develops; color developed more rapidly by heat. 1 68 TESTS AND REAGENTS. Kuelz (SuLPHOCYANic ACID IN URINE). Add water to dilute solut. ferric chloride containing a little HC1, until same color as urine, then add to urine a red color develops. Ktihl (Kousso FLOWERS). On adding to the weak aqueous maceration of the finely powdered kousso flowers, a i: 1,000 alkali solution, such as ammonia, or caustic soda, or potassa, an intense lemon- to orange-colored filtrate is obtained. This reaction is distinctly visible even in a maceration of i : 2,000. Ktihl (POMEGRANATE-ROOT BARK). In a i25~Cc. container, pour 100 Gm. distilled water over o.i Gm. finely powdered pomegranate-root bark. After shaking, the powder is pptd. within a very short time, while in the case of kousso flowers, complete separation does not take place, even after standing 12 hours. After macerating for 12 hours, at 10 to 15 C. and filtering, a slightly-yellow filtrate is ob- tained. On adding to this NH 3 , a very intense yellow is developed, which grows deeper, and finally changes to a red- dish-brown color. Kultschitzky (DOUBLE IMBEDDING METHOD). After the collo- dion bath, soak objects in origanum oil, then pass into a mix- ture of origanum oil and paraffin heated to not more than 40 C., and finally soak in pure paraffin. Kultschitzky (FIXING SOLUTION). A sat. solut. potassium bichromate and copper sulphate in 50-% alcohol, to each 100 Cc. of which 5 or 6 drops acetic acid are added at the moment of using. Fix objects for 1 2 to 24 hours in the dark, then treat with strong alcohol for 12 to 24 hours, and afterwards cut sections. Kultschitzky (STAIN FOR NERVE CENTERS). Harden for i or 2 months in Erlicki's solution, imbed in celloidin, and cut. Stain sections for i to 24 hrs. in solut. made from i Gm. hem- atoxylin in a little alcohol with enough 2-% acetic acid added to make 100 Cc. Wash out in sat. solut. lithium- or sodium carbonate containing 10% of a i-% solut. potassium ferri- cyanide, wash well with water, and mount in balsam. Kunz-Krause (GLYCOTANNOIDS). Those glucosidal tannins which are derivatives of oxycinnamic acids are rapidly decom- posed in the cold after a few days, with the formation of con- siderable prussic acid, on being treated with Liebermann's TESTS AND REAGENTS. 169 reagent (solut. potassium nitrite, 6 Gm., in cone. H 2 SO 4 100 Gm.). Kupferschlaeger (TARRY MATTER IN AMMONIA). A brownish- red color forms on supersaturating with not too cone. HNO 3 . Kuskow (DIGESTION FLUID). Recently prepared solut. of i part pepsin in 200 parts 3-% solut. oxalic acid. Labarraque (SOLUTION). Solut. sodium hypochlorite prepared like Javelle water (q. v.), using caustic soda instead of caustic potassa. Labich (COTTONSEED OIL). 25 Cc. of melted fat are mixed with 25 Cc. solut. of 500 Gm. lead acetate in i liter water, pre- viously warmed to 35 C., and 5 Cc. of ammonia water (22 Be.), and stirred for several minutes until a homogeneous emulsion results. If cottonseed oil present, the mixture is colored orange-red. Deiss modified this test for detecting cottonseed oil in olive oil, by dissolving 10 Cc. oil in 100 Cc. ether, shaking the solut. with 5 Cc. cone, lead-acetate solut. and again shaking after adding 5 Cc. ammonia water. Lachaux (INDICATOR). Corallin-malachite-green. Prepared by dissolving 3 . i Gm. commercial rosolic acid in 150 Cc. 90-% alco- hol, neutralizing, and mixing with a solut. of 0.5 malachite- green in 50 Cc. alcohol. Gives with alkalies a purple color, and with acids a green. Lacroix (TITANIUM). Dissolve the substance in HC1 with a gentle heat; add one drop of the solut. to a solut. of morphine in H 2 SO 4 . If the substance contains titanium the liquid ac- quires a wine-red color at once. If the substance does not dis- solve in HC1, fuse with Na 2 CO 3 and treat the melt with H 2 S0 4 , then add one drop solut. morphine, when the color will de- velop. Ladendorf (BLOOD). Tincture guaiac wood and oil eucalyptus are added to the liquid to be tested. If blood present the lower layer is colored blue; the upper one of oil eucalyptus, violet. Lafon (DIGITALIN). Digitalin yields a bluish-green color with a solut. of i Gm. sodium selenate in 20 Gm. cone. H 2 SO 4 (Lafon's reagent). In place of selenate, the tellurate may be employed. Lagerheim (STARCH IN DRUGS AND FOOD PRODUCTS). Reagent is iodolactic acid, obtained by dissolving a few crystals iodine 170 TESTS AND REAGENTS. in hot syrupy lactic acid. It strikes a blue color with air starch granules, and renders them visible. Lagrange (GLUCOSE). Modified Fehling's solut., containing neutral copper tartrate, 10 Grn., and sodium hydrate, 40 Gm., dissolved in water, ^oo Cc. It gives a red ppt. with glucose. Laillier (OLIVE OIL). Characteristic color reactions are obtained on shaking i volume aqueous i : 4 chromic-acid solut. with 4 volumes of oil. Or, the simple chromic-acid solut. may be replaced by a mixture of chromic acid, 9, water, 30, and HNO 3 (sp. gr. 1.185), 80. Lainer (BENZENE: BENZIN). i. Add a small fragment of iodine benzene is colored carmine-red; benzin is colored violet. 2. Add a trace of alcohol to liquid and shake with benzene mixture becomes cloudy; with benzin it remains clear. Toluene and xylene also give cloudy liquids with alcohol. Lamal (MORPHINE). Evaporate 2 to 10 drops morphine solut. on water-bath with a like quantity uranium-acetate solut. (0.015 Gm. uranium acetate and o.oi Gm. sodium acetate in 5 Cc. water). Light-red or hyacinth-red permanent streaks re- main. Oxymorphine, salicylic acid, tannin, gallic acid, and pyrogallol give a similar reaction ; toxines and most alkaloids do not. Landerer (STRYCHNINE). A violet color develops on heating gently with iodic acid or an iodate and H 2 SO 4 . Landois (MACERATING MIXTURE). Mixture of 5 parts each of cone, soluts. neutral ammonium chromate, potassium phos- phate, and sodium sulphate, with 100 parts distilled water. Used for macerations in the same way as chromic acid solut. Landolt (PHENOL). Upon adding an excess of bromine water to a phenol solut., a white crystalline ppt. of tri-bromphenol is formed. Similar ppts. result with cresol, oxybenzoic acid, indol, indican, kynurin, and other compounds, a fact to be remembered when examining urine for phenol. Landott (PARAFFIN IN BEESWAX). Strong H 2 SO 4 attacks bees- wax at once, but only very slowly affects paraffin. Landsberg-Wislicenus (MORPHINE IN URINE). Add acetic acid to urine, evaporate to syrupy consistency, extract with cold absolute alcohol repeatedly, evaporate alcohol, exhaust resi- UNI TESTS AND REAGENTS. 171 due with water, add few drops acetic acid to solut., and shake- out with amylic alcohol at 70 C. until washings no longer .colored. Evaporate residual aqueous acid solut., make resi- due alkaline and treat latter with hot amylic alcohol repeat- edly. Then evaporate solvent. Lang (FIXING LIQUIDS), i. 6 to 10 parts sodium chloride, 6 to 8 parts acetic acid, 3 to 12 parts mercuric chloride, 0.5 part alum, and 100 parts distilled water. The alum is sometimes omitted from this solut., which is used for Planaria. 2. Add 5 per cent, acetic acid to a cone, solut. mercuric chloride in picro-sulphuric acid. See also Kleinenberg. Lang (TAURINE). Taurine gives a white ppt. when a solut. is mixed with freshly pptd. mercuric oxide. Langbeck (INDICATOR). Nitrophenol gives colorless solutions with weak acids and neutral soluts.; color is changed to yellow by alkalies. Langbeck (METHYL ALCOHOL IN ETHER). Mix ether with a 2-% solut. silver nitrate and let stand 24 hours if methyl alco- hol present, zone of contact is light violet-red, and a ppt. of silver oxide forms proportionate to quantity of alcohol present. Langerhan (GuM AND GLYCERIN MEDIUM). Modified Farrant solut. Dissolve acacia in an equal weight of water, and to each 10 Gm. add 5 Gm. glycerin and 10 Gm. 5-% aqueous solut.. carbolic acid. Langley (ALKALOIDS). On adding a mixture of HNO 3 and H 2 SO 4 and then supersaturating with NaOH various alkaloids show characteristic colorations. See Dragendorff s " Ermit- telung der Gifte," p. 283. Langley (PEPSINOGEN AND PEPSIN). Sodium carbonate de- stroys pepsin, but has no action on pepsinogen. Langley (PICROTOXINE). Mix with 3 to 4 parts potassium ni- trate and moisten with H 2 SO 4 no reaction ; on adding excess of potassia, a reddish-yellow color develops. Langley-Koehler (ALKALOIDS). Mix alkaloids with from 3 to 5 times their weight of potassium nitrate, then add i to 2 drops- H 2 SO 4 , followed immediately by cone, soda-solution. Lanz (STAIN). Sat. solut. fuchsine in 2-% aqueous solut. phenol,. 10 Cc.; sat. solut. thionin in 2-% aqueous solut. phenol, 30 Cc. Stain specimen 15 to 30 seconds, and wash with water. Gono- 172 TESTS AND REAGENTS. cocci are stained by thionin; nuclei take both stains. Both solutions should be freshly prepared. Laronde (IODINE). On treatment with petroleum and nitric acid, the former is colored violet by the iodine. Lasaulx (IRON). Particles of Fe separated from a substance by a magnet and treated with solut. tungstic acid are seen under the microscope to have blue margins. Organic matter must be absent, as well as zinc and copper. Lassaigne (ACACIA). A transparent, gelatinous, yellow ppt. is obtained on adding solut. ferric sulphate. Lassaigne (FLOUR). Mineral substances in flour are detected by shaking with chloroform and examining sediment. Lassaigne (HYDROCYANIC ACID). A few drops KOH solut., fol- lowed at once by a few drops of copper- sulphate solut. and slight acidulation with HC1 causes a white ppt. of cuprous cy- anide if HCN present. A solut. of copper sulphate in sulphur- ous acid will also yield a ppt. in solutions containing HCN. Lassaigne (IODINE), i. Solut. palladium nitrate or chloride affords a brown or blackish color. 2 . On treating with chlo- rine water, an iodide colors starch-paper blue. Lassaigne (ORGANIC NITROGENOUS COMPOUNDS). Heat about o.o i Gm. of substance with a small piece sodium, add 2 to 3 Cc. water and some ferroso-ferric salt solut. and acidulate with HC1 if any nitrogenous body present, a ppt. of Prussian blue forms. Latschenberger (AMMONIA IN URINE). Treat urine with equal volume sat. solut. copper sulphate, neutralize with barium hydrate, filter, and apply Nessler's test to filtrate. Laubenheimer (THIOTOLENE). This substance yields a bluish- green color with a solut. anthraquinone in glacial acetic acid. The coloring matter is pptd. by water, but is redissolved by ether to form a violet solut. Laubenheimer- Go deffroy (ALKALOIDS). See Godefjroy-Lauben- keimer. Lauth (PARATOLUIDINE). Add HNO 3 to a solut. paratoluidine in H 2 SO 4 color changes from blue to violet, then to red, and finally brown. Lauth (SULPHURETTED HYDROGEN). Paraphenylene-diamine in slightly acid solutions, gives, on adding ferric chloride, a TESTS AND REAGENTS. 17$ violet color if sulphuretted hydrogen present. If a few grains para-amido-dimethylaniline sulphate are substituted for the paraphenylene-diamine, a reaction due to methylene blue is, obtained (Caro- Fischer's reaction). Lavdowsky (BILLBERRY-JUICE STAIN). Well wash fresh ber- ries of V actinium myrtillus, then express juice and mix with twice its bulk distilled water mixed with a little 90-% alcohol. Heat for a short time and filter while warm. Dilute stain with 2 or 3 volumes distilled water before use. Lavdowsky (CHLORAL-HYDRATE MACERATING MEDIUM). A 5-% aqueous solut. of chloral hydrate. Lavdowsky (FORMALDEHYDE SOLUTIONS), i. Distilled water, 20 parts, alcohol (95-%), 10 parts; formaldehyde (40-%), 3 parts; glacial acetic acid, 0.5 part. 2. Distilled water, 30. parts; alcohol (95-%), 15 parts; formaldehyde (40-%), 5 parts; glacial acetic acid, i part. Lavdowsky (SANDARAC MEDIUM). Dissolve 30 Gm. sandarac in 50 Cc. absolute alcohol. If diluted with an equal volume ab- solute alcohol, this may be used for clearing sections. Lawrence (GLYCERIN JELLY). Soak Nelson's gelatin in cold water for 2 or 3 hours, then pour off superfluous water. Next melt the gelatin, and after cooling somewhat, add to each fl. oz. a fluid dram egg albumin. Boil until albumin coagul- lates, then filter through fine flannel, and to each fl. oz. of the- clarified solut. add a mixture of 0.25 fl. oz. glycerin and 0.5, fl. oz. camphor water. Lea, Carey-. See Carey-Lea. Lebbin (FORMALDEHYDE). Heat solut. containing formalde- hyde to boiling for 30 seconds with a solut. resorcin in sodium hydrate. Formaldehyde gives a reddish tint, but albumi- noids, if present, interfere with the reaction; chloroform affords a similar color. Leber (PRUSSIAN BLUE IMPREGNATION METHOD). Treat tissue for a few minutes with 0.5-% solut. ferrous sulphate, then with i-% solut. potassium ferricyanide, and wash with water. Lechini (BLOOD IN URINE). Treat 10 Cc. urine with a drop glacial acetic acid and shake with 3 Cc. chloroform if color- ing matter from blood present, the chloroform will form a red layer at the bottom. 174 TESTS AND REAGENTS. Leconte (URIC ACID). See Babo's test. Lee (CELLOIDIN IMBEDDING METHOD). Objects are penetrated first with a 4- to 6-% solut. celloidin in a mixture of equal parts ether and absolute alcohol, and subsequently with a 10- to 1 2-% solut. (see Elsching's solut.). They are then arranged in posi- tion in small paper receptacles, which are filled with the thick solution and placed in a desiccator, on the bottom of which a little chloroform must be poured. When celloidin masses are hardened sufficiently on surface, remove them from the paper cases and turn them over from time to time, in order that they may be equally exposed on all sides to the action of chloroform vapor. As soon as masses are fairly hard, immerse them in Gilson's hardening mixture (chloroform, i part; cedar oil, i or 2 parts) and replace ^the chloroform as it evaporates with more cedar oil. When the objects are cleared throughout, expose the masses to the air, so that the last traces of chloroform may evaporate, and they will then be ready for mounting on holder of the microtome by means of a drop of thick celloidin solution. Lee (FORMALDEHYDE SOLUTIONS), i. i part of 40-% for- maldehyde solut., 2 parts i-% chromic-acid solut., and 4-% acetic acid. 2. i part 40-% formaldehyde solut., 4 parts of i-% platinic-chloride solut., and 2-% acetic acid. Lee (GLYCERIN MIXTURE), i part glycerin, i part alcohol, and 2 parts water. Lee ("KERNSCHWARZ" STAIN). Stain material, if fresh, in " Kernschwarz " diluted with 10 volumes of water for a few minutes; otherwise leave in the undiluted liquid for 24 hours. Rinse in water, and then stain for 24 hours or more with safra- nine, gentian violet, Victoria blue, or a hematein stain. Safra- nine is preferred, and should afterwards be extracted with alcohol (acidulated, if necessary), followed by clove oil " Kernschwarz" is said to be a good stain for preparations that are to be photographed. Lee (MOUNTING CELLOIDIN SECTIONS). Mount sections on Mayer's albumin, taking care to press them down very thor- oughly, and remove the celloidin, if desired, by immersion in ether-alcohol. Lee (OsMic-Acio AND PYROGALLOL STAIN). Fix tissues in Her- mann's mixture or Flemming's mixture for half an hour, then TESTS AND REAGENTS. 175 place in a weak solut. pyrogallol, which may be prepared with alcohol in some cases. Safranine may be used as a second stain. Lee (SUBLIMATE SOLUTION). See FrenzeVs sublimate solution. Xee (TURPENTINE-COLOPHONY MOUNTING MEDIUM). Highly recommended for general work, and is prepared by adding small pieces colophony to rectified oil turpentine, heating in a .stove, and when solut. sufficiently thick, filtering twice in the .stove. See Kleinenberg s colophony. Xeers (QUININE). A green color develops on shaking quinine in fine powder with ether, then adding chlorine water and am- monia. Xeewenthal-Lenssen (HYDROCHLORIC ACID). With a proto- chloride, free HC1 gives off chlorine on treatment with lead peroxide. Leffmann (URINE). Drinking water containing urine is colored brown with silver-nitrate solut. Xeffmann- Beam (FAT IN MILK ANALYSIS). Method consists in decomposition of milk with H 2 SO 4 in a graduated tube, and separating the fat by means of a centrifugal machine, a little fusel oil being added to aid aggregation of oil globules. Xefort (MORPHINE). A yellow to yellowish-brown color de- velops on adding iodic-acid solut. and then ammonia. Xefort (STRYCHNINE). A violet color develops with H 2 S0 4 and potassium bichromate. Xegal (ACETONE IN URINE). Treat several Cc. of distillate from urine with a few drops freshly prepared solut. sodium nitro- prussiate and a few drops of soda or potassa lye a red color develops. After this has faded, add excess acetic acid. If acetone present, a purple color is produced. Creatinine also shows a fading of the first-formed red color, but upon the addi- tion of acetic acid, first a green and then a blue color forms. See Le Noble's reaction. Xegal (ALUM-CARMINE AND PiCRic-Acio STAIN). Mix 10 vol- umes Grenacher's or other alum-carmine with one of sat. picric- acid solut. Xeger (BISMUTH REAGENT). A solut. of cinchonine nitrate with potassium iodide, with which bismuth salts give a dark-red ppt. 176 TESTS AND REAGENTS. Leger (DIFFERENTIATING ALPHA-NAPHTOL FROM BETA-NAPHTOL). Soda-lye (36 Be.), 30 Cc.; water, 100 Cc.; bromine, 5 Cc. Add 2 drops of this hypobromite solut. to 10 Cc. cone, aqueous, solut. of substance if alpha-naphtol present, a dirty- violet color develops. With beta-naphtol a yellow color first forms, then turns greenish, and finally yellow. With alpha-naphtol reaction is obtained even on diluting cone, solut. with 9 parts water; on diluting beta-naphtol solut. with 2 parts water, a yellow color is still obtained, but it disappears at once on agi- tation. Reaction for beta-naphtol much less sensitive than for alpha-naphtol. Lehmann (GLUCOSE). Dissolve substance in alcohol, add alcoholic potassa solut., then copper sulphate solut., and warm if glucose present, separation of red cuprous oxide results. Lehman- Petri (INDICATOR). Phenol nitrosylsulphonate. Gives, a blue color with alkalies, and a red with acids. Leismer (SUGAR IN URINE). 5 Cc. o.i-% solut. safranine, i Cc. urine, and 2 Cc. soda lye are heated to boiling if glucose pres- ent, the solut. is decolorized. Le Noble (ACETONE IN URINE). Upon adding sodium nitro- prussiate and ammonia to urine containing acetone a violet color gradually forms. See Legal' s test. Lenz (ALKALOIDS). Certain alkaloids give characteristic color reactions when heated to redness with caustic potassa, con- taining so much water that it is solid at ordinary temperature, but melts when heated on the water-bath. Quinine and quinidine give a green color; cinchonine and cinchonidine a. greenish blue; cocaine a greenish yellow. Lenz (PILOCARPINE). Triturate the alkaloid or its hydrochlo- rate with 100 parts calomel a gray to black color develops, due to reduction of calomel. In case of pilocarpine nitrate, according to Nagelvoort, the free base must first be liberated by NH 3 , and extracted with chloroform. The residue left on evaporation of latter is then treated as above. Lenz (SHIKIMI FRUIT IN STAR ANISE). Boil i carpel for 2 min- utes with 5 Cc. 95-% alcohol, cool, filter, and add 4 to 5 vol- umes of water to filtrate if fruit star anise, liquid becomes cloudy (due to anethol); if shikimi, liquid remains clear. If TESTS AND REAGENTS. 177 shikimi extract shaken with petroleum ether, ethereal ex- tract scarcely leaves any residue on evaporation, and the trace left has a disagreeable odor. Star-anise extract similarly treated leaves an oily residue of anise odor. Leonard! (ALCOHOL IN ESSENTIAL OILS). Fuchsine dissolves in alcohol, but not in the pure oils. Leonard! (CASTOR OIL IN OLIVE OIL). Shake 10 Cc. suspected oil with 5 to 10 Cc. 95-% alcohol and set aside till two distinct layers form. If olive oil pure, its volume will increase; if castor oil present, alcohol volume will increase. Lepage (ALKALOIDS). A white or yellowish ppt. is afforded by a solut. of cadmium iodide, 10, and potassium iodide, 20, in water, 60 to 80. See Marmes test. Lepage (POTASSIUM IODIDE). Test purity of potassium iodide by dissolving in 30-% alcohol and examining residue, if 'any. Lepel (MAGNESIUM SALTS). The violet color of a solut. of alkanin in a mixture of alcohol, 2, and ether, i, is changed to blue. Letheby (ANILINE), i. A blue to purple color is given with H 2 SO 4 and lead or manganese dioxide. 2. A blue to purple color is afforded with H 2 SO 4 and potassium ferricyanide. 3. A bronze-blue to pink color develops on adding dil. H 2 SO 4 , placing 2 drops on platinum foil and passing a current from a Grove battery. 4. A blue color forms upon heat- ing to 50 C. with manganese dioxide and diluted sulphuric acid. Letheby (ARSENIC). Cause evolution of arseniuretted hydro- gen and pass gas into silver-nitrate solut. the latter is colored brown to black. Leube (QUININE). Chlorine water, potassium ferrocyanide, and ammonia cause a red color. Leuchs (WATER IN ESSENTIAL OILS). Shaking with petroleum spirit causes a cloudiness. Lewin (ACROLEIN AND OTHER ALDEHYDES). Add a trace to mixture of piperidin and sodium nitroprussiate a gentian- blue color develops, changed to violet by NH 3 ; to reddish- violet, then rust-color by NaOH; to bluish-green by glacial acetic acid; and to rusty-brown by mineral acids. On adding 178 TESTS AND REAGENTS. water, however, the blue color is restored. Hydrogen diox- ide gives a dirty-brown. Instead of piperidin, dimethyl- amine may be used. Reaction is afforded with acetaldehyde, paraldehyde, propionic aldehyde, formaldehyde, trichloral- dehyde, isobutyraldehyde, benzaldehyde, salicylaldehyde, phenylacetylaldehyde, cenanthol, and furfural. Lewin (BILIARY PIGMENTS). The urates separated by strongly cooling urine are filtered out, washed, dissolved in hot water, and the solut. tested for biliary pigments. See Gmelin's test. Lewin (SESAME OIL). See Baudouin's test. Lewis, Bevan- (BLUE-BLACK NERVE-CENTER STAIN). Sections are stained for one hour in 0.25-% aqueous solut. aniline blue- black, and in the case of the cortex of the cerebellum, washed out for 20 to 30 minutes in a 2-% chloral solut., prior to clean- ing and mounting. Lewis, Bevan- (HARDENING PROCESS FOR BRAIN). Keep in methylated spirit for 24 hours in a cool place, then transfer to Mueller's solut. for 3 days, after which change the liquid and, at end of another 3 days, substitute a 2-% solut. potassium bichromate. At end of 2 weeks use a 4-% solut. bichromate, and if material is unfit for section cutting in another week, treat with chromic-acid solut. Lewy (COCAINE HYDROCHLORATE). On adding borax to an aqueous solut. a ppt. forms, soluble in glycerin. On warming this solut. latter becomes cloudy, but clears up again on cool- ing. Lewy (SYPHILIS-TUBERCLE STAIN). Stain with carbol-fuch- sine and decolorize with water. Lex (AMMONIA). Phenol and chlorinated-lime solut. develop a green color which changes to blue on warming. Lex (PHENOL REACTION). Add a solut. of a hypochlorite (chlo- rinated-lime solut. i : 20), or bromine water (Cotton's modifi- cation), to an ammoniacal phenol solut. a green color devel- ops', changing to blue upon warming. Leys (SACCHARIN). To 5 Cc. of a i : 2,500 solut. saccharin add 2 drops dil. solut. Fe 2 Cl 6 and 2 Cc. H 2 O 2 in from 30 to 45 min- utes a permanent violet color develops. Lidof (ALBUMINOIDS). On gently heating a solut. of any albu- minoid substance with AgNO 3 and a slight excess KOH a TESTS AND REAGENTS. 179 Thrown color develops, growing darker until liquid has a very deep tint. Lidoff (TEXTILE FABRICS). Silk is readily soluble in powdered oxalic acid (on fusing). Cellulose is less soluble, and wool fiber insoluble. Lidow (ALBUMINOIDS). Warm a solut. of a proteid with silver nitrate and slight excess of caustic potassa color gradually darkens until cinnamon-brown. Lieben (ACETONE). To solut. (e. g., urine distillate) add a solut. iodine in potassium iodide and a few drops of caustic-potassa solut. iodoform forms if acetone present. Alcohol gives the same reaction. See Gunning's test. Lieben (ALCOHOL). Iodoform forms on adding a fragment of iodine and sufficient potassa to make a clear solution. Lieben (FORMIC ACID). Reducing action of formic acid on po- tassium permanganate is utilized for determining acid present in a liquid. For details see MERCK'S REPORT, iv, p. 47. Liebermann (ALBUMINOIDS). Fuming HC1 affords a bluish- violet color with albuminoids on boiling. Liebermann (CHOLESTERIN). A solut. of cholesterin compounds in acetic acid anhydride, and, according to Burchard, with addition of chloroform, is colored rose-red by cone. H 2 SO 4 . The color rapidly changes to blue and green. Liebermann (DiAzo- AND NITROSO COMPOUNDS). These yield intense colors with a mixture of phenol and H 2 SO 4 . Liebermann (GLYCOTANNOIDS). Potassium nitrate, 6 Gm.; cone. H 2 SO 4 , 100 Gm. Glycotannoids are decomposed by reagent with formation of HCN. Liebermann (LANOLIN). Dissolve o.i to 0.2 Gm. lanolin in 4 Cc. acetic-acid anhydride and add H 2 SO 4 a rose-red color, chang- ing to green or blue, develops. Glycerin fats do not give the reaction. Liebermann (PHENOL). Warm phenol with H 2 SO 4 , in which 5% sodium nitrate has been dissolved blue color forms. Addi- tion of water causes a brown ppt. Liebermann (SULPHUROUS ACID IN WINE), i. Reduce to sul- phuretted hydrogen with sodium amalgam and HC1. 2. Distil, and shake distillate with few drops solut. iodic acid and some chloroform latter is colored violet. i8o TESTS AND REAGENTS. Liebermann (TEXTILE FABRICS). Dye fabric for half an hour im a fuchsine solut. rendered light-yellow by caustic-soda solut. and then wash with water silk is colored dark-red; wool, light-red; flax, pink; cotton remains colorless. Lie big (ALDEHYDE). Ammoniacal solut. silver nitrate causes formation of a mirror. Liebig (CONIINE). On passing dry chlorine gas over coniine, the latter acquires a purplish-red to blue color. Liebig (CYANIDES). Titrate in slightly alkaline solut. with deci- normal silver-nitrate solut. till permanent opalescent ppt. forms, i Cc. AgNO 3 solut. = 0.0054 HCN. Liebig (CYSTINE). The cystine obtained from urine sediment yields a black ppt. of lead sulphide on boiling with solut. lead, oxide in soda lye. Liebig (HYDROCYANIC ACID). On evaporating HCN with am- monium sulphide after adding a few drops caustic-potassa solut., dissolving residue in water, and acidulating slightly with HC1, a blood-red color forms upon adding ferric-chloride solut. Liebig (QUININE). Shake 0.5 Gm. quinine sulphate in a stop- pered test-tube with 5 Cc. of ether (sp. gr. 0.728) and i Cc. of ammonia two clear layers should form on standing. A tur- bidity indicates presence of cinchonine or allied alkaloids. Compare with the more delicate tests of Kerner, Schaefer, and De Vry. Liebig-Woehler (UREA). On evaporating a urea solut. with silver nitrate, silver cyanate and ammonium nitrate are formed. Liebman (ALPHA-NAPHTOL IN BETA-NAPHTOL). Dissolve 0.144 Gm. naphtol in 5 Cc. alcohol and 15 Cc. toluene in a graduated tube. In a separate tube dissolve 0.14 Gm. paranitraniline in 9 Cc. dil. HC1, cool, and diazotize with i Cc. normal sodium- nitrite solut. Add i Cc. of latter solut. to naphtol solut., shake, and add water. After two layers formed, remove tolu- ene layer and shake it with 5 Cc. normal caustic-soda solut., and compare color with that similarly obtained with a solut. beta-naphtol containing known quantities of alpha-naphtol. Liebreich (CHOLESTERIN AND CHOLESTERIN FATS). See Bur- chard's test. TESTS AND REAGENTS. i8l Lifschuetz (CELLULOSE). Mixture for dissolving cellulose con- sists of a mixture of H 2 SO 4 and HNO 3 . Lightfoot (PYROLIGNEOUS MATTER IN ACETIC ACID). Neutral- ize with sodium- or potassium carbonate and add a few drops solut. potassium permanganate the pink color of the latter is discharged in a few minutes. Linde (GLYCERIN IN FLUID EXTRACTS). i. Render solution slightly alkaline with dilute sodium-carbonate solut., then mix with powdered borax on a watch crystal if glycerin present, a small quantity of the mixture introduced into an alcohol or gas flame upon a platinum wire will color the flame green. 2. Red litmus-paper is made blue by saturating with a cone, borax solut. Upon moistening this paper with the glycerin solut. previously rendered slightly alkaline, the red color re- appears more or less rapidly, depending on the concentration of glycerin solut. See also Hager's glycerin reaction. Lindemann-Motten (ALKALOIDS, SACCHARIN, AND SALICYLIC ACID). Detection depends upon fact that a substance in pres- ence of two non-miscible solvents (separated by a membrane) passes into both, and in definite proportions. For details see MERCK'S REPORT, ii, p. 212. Lindo (ALKALOIDS). Dissolve alkaloid in diluted H 2 SO 4 , and add ferric chloride. For resulting color reactions, see Hager's "Pharm. Praxis," 1886, III, p. 64. Lindo (ELATERIN). Treat with i or 2 drops phenol and 2 or 3 drops H 2 SO 4 a crimson to scarlet color develops. Lindo (GLUCOSE). Add a solut. of brucine in HNO 3 to a solut. of glucose in soda- or potassa lye a yellow color, changing to an intense blue, develops. Lindo (MORPHINE). Copper sulphate, i; water, 10; ammonia, sufficient to make a clear solut. Reagent gives with mor- phine an emerald-green color. Lindo (NITRATES AND, NITRITES). One drop 15-% HC1, one drop of io-% resorcin solut., and 2 Cc. pure cone. H 2 SO 4 to 0.5 Cc. of a solut. of a nitrate or nitrite, yields a purple-red color. Lindo (NITRIC ACID). A deep-brown to red color develops on adding to nitric acid 8 or 10 drops phenol mixed with 30 drops of a cooled mixture of H 2 SO 4 , 2, and water, i. 1 82 TESTS AND REAGENTS. Lindo (PHENOL). Inverted nitric-acid test (q. v.). Lindo (SACCHARIN). Evaporate saccharin to dryness with cone. HNO 3 , treat residue with a few drops solut. potassa in 50-% alcohol, and warm blue, violet, purple, and red colors appear in succession. Lindo (SANTONIN). Dissolve in H 2 SO 4 without heat, and add very dilut. solut. ferric chloride in small successive quantities a red to purple or violet color develops on agitating. Lipowitz (OLIVE OIL). Purity of oil is estimated by noting color, degree of emulsification, etc., on rubbing it with one- eighth its weight chlorinated lime. Lipowitz (PHOSPHORUS IN ORGANIC MATTER). Add H 2 SO 4 , boil half an hour with some lumps of sulphur, and distil. Wash sulphur and examine for luminosity and odor. Add some HN0 3 to distillate, and test for phosphoric acid. Lipp (DEXTRIN). A cold sat. solut. lead acetate is heated to 60 C. with sufficient lead oxide to solidify the mass, which is later extracted with water, and the solut. filtered. This solut. gives a white ppt. when boiled with a dextrin solut. List (HEMATOXYLIN-EOSINE STAIN). Stain sections for 24 hours in a solut. of 3 or 4 drops Renaut's hematoxylin-glycerin in 250 Cc. water, and then for a few minutes in a mixture of i part 0.5-% aqueous solut. eosine with 3 parts absolute alcohol. List (METHYL-GREEN-EOSINE STAIN). Stain sections for a few minutes in a mixture of 3 parts absolute alcohol with i part of -5-% aqueous solut. eosine, then wash, and stain for 5 min- utes in a 0.5-% aqueous solut. methyl green. Wash, dehy- drate, clear, and mount in balsam. Livache (FATTY OILS). Note increase in weight of oils when mixed with finely divided lead. Lloyd (ALKALOIDS). Hydrastine mixed with various alkaloids, and treated with cone. H 2 SO 4 for 5 minutes gives various reac- tions. For details see MERCK'S REPORT, x, p. 258. Lloyd (WATER IN SPIRIT NITROUS ETHER). Milkiness is pro- duced on shaking with chloroform or ( ? and) castor oil. Lochini (ALKALOIDS). Solut. potassium bichromate in hot cone. H 2 SO 4 gives with veratrine a yellow color. Loeffler (BACTERIA STAIN). Place section in Loeffler's methyl- ene-blue solut. (or cone. aq. solut. of any stain will do), then TESTS AND REAGENTS. 183 place in 0.5-% acetic acid solut. for a few seconds, then in absolute alcohol and in cedar oil, and mount in Canada balsam. Loeffler (FLAGELLA STAIN), i. Prepare mordant by adding 5 Cc. cold sat. solut. ferrous sulphate and i Cc. aqueous or alco- holic solut. fuchsine, methyl violet or " Wollschwarz," to 10 Cc. of 20-% aqueous solut. tannin. Typhoid bacilli re- quire addition of i Cc. of i-% solut. sodium hydrate; Bacil- lus subtilis require 28 to 30 drops, and the bacilli of malignant cedema require 36 to 37 drops. In case of cholera bacteria add 0.5 to i drop H 2 SO 4 to the soda solution, and for Spirillum rubrum add 9 drops. Cover-glass preparations are made and fixed in the flame, then treated with above mordant and heated for half a minute, after which they are washed in distilled water and then in alcohol. Stain by treating in a similar manner with a sat. solut. fuchsine in aniline water, the solut. being preferably neutralized to point of precipitation by cautiously adding o.i-% NaOH solut. 2. Gallic-acid solut. i in 4, 10 Cc.; cold sat. ferrous sulphate, 5 Cc.; and alcoholic fuchsine solut., i Cc. Fischer's modification of this consists of tannin solut. i in 10, 20 Cc. ; ferrous- sulphate solut. i in 2, 4 Cc.; and alcoholic solut. fuchsine, i Cc. The sec- tions are macerated in this with heat, washed in water, then stained with cone, aqueous solut. fuchsine. For further details see Journal of the Royal Microscopical Society, 1890, p. 678. Loeffler (MACERATING FLUID), a. To 10 Cc. of a 20-% aq. solut. tannin add, drop by drop, aq. solut. ferrous sulphate until solut. is deep violet. Then add 3 to 4 Cc. logwood in- fusion (i : 8). If more logwood is added, a granular condi- dition occurs, which renders the staining functions of the solut. useless. The fluid is dark- violet for several days, then grad- ually changes to deep-black. The scum which develops on the surface does not interfere with the solut. The addition of 4 or $ Cc. of 5-% carbolic acid renders the solut. perma- nent, and does not affect the macerating strength materially. Keep solut. in well-stoppered bottles, b. Tannin solut. (20-%) 10 Cc.; sat. solut. ferrous sulphate, 5 Cc.; aqueous or alcoholic solut. fuchsine, mefhy! violet, or wool black, i Cc. 1 84 TESTS AND REAGENTS. Loeffler (WEAK ALKALINE ANILINE WATER). Add i Cc. of a i-% solut. NaOH to 100 Cc. saturated aniline water. Loeffler (SOLUTION). Cone, alcoholic solut. methylene blue, 30 Cc.; solut. potassium hydrate (i: 10,000), 100 Cc. Mix and filter shortly before use. Stain sections for a few minutes (tubercle sections for some hours), and remove excess of stain by immersion for a few seconds in 5-% acetic acid. Dehy- drate in absolute alcohol, clear in cedar oil, and mount in balsam. Loew (CREATIN). On treatment with ammoniacal copper crea- tin is oxidized to oxalic acid and methylguanidin. Loewe (GLUCOSE). Solut. of 16 Gm. copper sulphate in 64 Gm. water with 80 Cc. soda lye (sp. gr. 1.34) and 6 to 8 Gm. of glyc- erin (gradually added to avoid heating), gives with glucose or diabetic urine a red ppt. upon warming. For quantitative estimation the reagent is prepared as follows: 15.621 Gm. of cupric hydroxide (from 40 Gm. of crystallized copper sulphate) are warmed while still moist, with 30 Gm. of glycerin, 80 Cc. soda lye (sp. gr. 1.34), and 160 Cc. water until dissolved, and sufficient water added to make whole measure 1155 Cc. 10 Cc. of this solut. correspond to 0.05 Gm. glucose. See Fehl- ing's solution. Loewenthal (GLUCOSE). Solut. of 60 Gm. tartaric acid, 240 Gm. of sodium carbonate, and 5 Gm. crystallized ferric chloride in 500 Cc. hot water gives with glucose solut. or diabetic urine a brown ppt. when boiled with it. Loewenthal (HYDROCHLORIC ACID). Lead peroxide liberates chlorine in solutions containing free hydrochloric acid and chlorides (other than those of iron and tin). Longi (NITRIC ACID). An aqueous solut. paratoluidine sul- phate gives with a solut. containing HNO 3 on the addition of an equal volume of cone. H 2 SO 4 a red zone, which later changes to yellow. In the presence of chlorates, bromates, iodates, chromates, and permanganates, a blue color develops. Ni- trous acid gives a yellow color afterwards changing into red. Loof (MORPHINE). Froehde's reagent in different strengths yields different reactions with morphine. A solut. 0.05 to o.i Gm. ammonium molybdate in i Cc. H 2 SO 4 yields a dark-lilac color changing to a permanent blue. A solut. of o.ooi Gm. salt in TESTS AND REAGENTS. 185 i Gm. H 2 SO 4 gives first a lilac, then a dirty greenish-blue be- coming yellowish by degrees. A solut. of o.oi Gm. molyb- date in i Cc. acid causes a dark-lilac, then dirty-brown grad- ually becoming green. Loubian (.INDICAN). Modification of Hammarsten's reaction, in which hydrogen dioxide is substituted for calcium hypo- chlorite to convert indican into indigo. Two Cc. urine are mixed with an equal volume chloroform and i Cc. of 5- to io-% solut. hydrogen dioxide. Cone. HC1, 2 Cc., is then added, and the mixture warmed and well shaken; the presence of indican is shown by the deep-blue color of chloroform layer. Lovett (CEMENT). Grind very fine and mix dry 2 parts white lead, 2 parts red lead, and 3 parts litharge. Keep powder in a bottle, and when required for use mix a little with japanner's gold size to consistency of paint. Xowe (CRYSTALLIZABLE PHENOLS IN "CARBOLIC" DISINFEC- TANTS). Distil 100 Cc. in two fractions, the first containing all the water and 10 per cent, of the oils, the second 62.5 per cent. This fraction is cooled, a crystal of phenol added, and the rise in temperature on crystallization taken with a delicate thermometer. From this the quantity of phenol present is deduced. Lowit (GOLD METHOD). Place small pieces of fresh skin in formic acid (sp. gr. 1.12) diluted with an equal bulk water, and when epidermis peels off transfer to 1.5- or i-% gold-chloride solut. for 15 minutes; next treat, in the dark, with dilute formic acid (i part with i to 3 of water) for 24 hours, and sub- sequently for a smiliar length of time with undiluted formic acid. Thin sections are then cut and mounted in dammar or glycerin. Luchini (VERATRINE). Solut. potassium bichromate in hot cone. H 2 SO 4 gives with veratrine a yellow color. Luchsinger (GLYCERIN IN URINE). The alcoholic extract has a sweet taste, dissolves copper hydrate in presence of soda-lye, and on distillation with potassium bisulphate yields acrolein. Luck (CARBON DISULPHIDE IN MUSTARD OIL). Distil oil in a water-bath and add to distillate alcoholic potassa solut., a slight excess acetic acid, and copper-sulphate solut. A lemon- yellow ppt. indicates presence of carbon disulphide. i86 TESTS AND REAGENTS. Luck (INDICATOR). Phenolphtalein. Colorless with acids; pur- plish-red with alkalies. Ludwig (ALCOHOL). See Otto's test. Ludwig (ANILINE). Add phenol and solut. sodium hypochlorite- to aqueous solut. a dark-blue develops, changed to red by HC1. Ludwig (MERCURY IN URINE). The mercury is pptd. on metal- lic zinc or copper, and the amalgam heated in a capillary tube,, the sublimed and evolved mercury being then identified by conversion into red iodide. Ludwig (POTASSIUM CHLORATE IN VOMIT). Add acetic acid, boil for i minute, filter, evaporate to small bulk, and set aside. Collect crystals and dry with blotting paper. Treat crystals with warm dil. HC1 chlorine gas is evolved. Luebimoff (BOROFUCHSINE). To 20 Cc. dist. water add 0.5 Gm. boric acid, then add 15 Gm. absolute alcohol; when dissolved add 0.5 Gm. fuchsine, and agitate. Luebimoff (LEPRA BACILLUS STAIN). Stain section to 24 hours in borax-fuchsine, then place in H 2 SO 4 (1:5) for a few seconds till dark-brown color changes to yellow-brown, then wash in alcohol, place in oil, and mount in balsam. Luebimoff (TUBERCLE DOUBLE STAIN). Stain 24 hours in cold borax-fuchsine solut., decolorize in H 2 SO 4 (1:5). Decolor- ization is not as rapid as with lepra bacilli (differentia- tion). Luecke (HIPPURIC ACID). Heat residue obtained by boiling to dryness a mixture of hippuric acid and cone. HN0 3 a strong odor of nitrobenzene develops. Luedy (UREA). Add excess of orthonitro-benzaldehyde to alcoholic solut., evaporate to dryness; wash residue twice or thrice with warm alcohol, and boil it with a solut. of phenyl- hydrazine hydrochlorate and 5 to 10 drops io-% H 2 SO 4 urea causes a redness. Luff (URic ACID IN BLOOD). Fresh blood is allowed to flow direct into its own volume rectified spirit, with which it is thoroughly agitated; the mixture is then evaporated on water- bath until the mass can be reduced to a coarse powder, which is dried in the water-oven and afterwards finely powdered. The admixture of the blood with the spirit precipitates the- TESTS AND REAGENTS. 187- albuminous matters in a granular form, so that when dried' the blood can be reduced with ease to a fine powder. One- part of the dried blood is taken as being equal to five parts of liquid blood. For the extraction and estimation of uric acid, in blood, from 50 to 100 Gm. of the powdered blood should, if possible, be taken. The extraction is effected by adding 100, Gm. powdered blood to a liter boiling distilled water, and allowing the mixture to boil for half an hour, during which time it is frequently agitated. It is then filtered, first through glass-wool, and afterwards through filter-paper, and evapo- rated down to 50 Cc.; this liquid is filtered, allowed to cool^ and then submitted to the Gowland-Hopkins process for the determination of uric acid. See the Journal of Pathology and. Bacteriology, 1893, i, p. 451. Lugol (ALBUMIN IN URINE). Iodine, 2 Gm. ; potassium iodide t 3 Gm. ; water, 250 Gm.; glacial acetic acid, 250 Gm. Lugol (INJECTION). Iodine, 1.2 Gm.; potassium iodide, 1.8 Gm, water, to make 30 Gm. Lugol (STAINING BACTERIA). Iodine, i; potassium iodide, 2; water, 300 (or Gram's iodine solut.). Bacteria are stained in a solut. made by shaking 15 drops aniline with 15 Cc. water ^ filtering, and adding 4 or 5 drops gentian- violet solut. After staining, they are immersed in the iodine solut., then in ab-. solute alcohol until decolorization. Certain bacilli (e. g., an-, thrax) retain the color; others (cholera, typhoid, bacterium coli) are decolorized. Lunge (BicARBONATES IN CARBONATES). To a weighed quan- tity of solid bicarbonate add excess semi-normal NH 3 followed by excess of barium chloride. The whole is made up to a known volume and a definite portion filtered through a dry filter. This is then titrated with normal acid. Alkalinity indicated represents the carbon dioxide existing as bicarbon- ate in the quantity of liquid taken. Lunge (INDICATORS), i . Tropaeolin or methyl-orange changed from yellow to crimson by mineral acids, but indifferent to carbon dioxide and sulphuretted hydrogen. 2. Phenacetolin obtained by heating for several hours i equivalent each of carbolic, sulphuric, and glacial acetic acids color changed from brown to red by alkalies. 1 88 TESTS AND REAGENTS. Lunge (NITROUS ACID). Depends upon Griess reaction (q. v.) with sulphanilic acid and alpha-naphtylamine, which, ac- cording to Lunge, are kept on hand dissolved in dilute acetic acfd. Solut. containing nitrous acid is colored red by this reagent. For quantitative determinations employ: Lunge- Lwoff (NITROUS ACID). Colorimetric test carried out by means of solut. o.i Gm. alpha-naphtylamine in 100 Cc. water, 5 Cc. glacial acetic acid, and i Gm. sulphanilic acid, in 100 Cc. water. Normal solut. contains o.'oi Mg. nitrogen from nitrites per Cc. (0.0493 Gm. sodium nitrite dissolved in 100 Cc. water, and 10 Cc. of this solut. diluted to 100 Cc. with cone. H 2 SO 4 ). Place in each of two cylinders i Cc. reagent and 40 Cc. water, then add to the one 5 Gm. sodium acetate, and i Cc. normal solut. of substance; to the other, 6 Cc. solut. to be tested compare the colors. Lunge-Lwoff (NITRIC ACID IN PRESENCE OF NITROUS ACID). Colorimetric determination by means of a solut. of 0.2 Gm. brucine in 100 Cc. pure cone. H 2 SO 4 . Mix i Cc. normal solution (10 Cc. solut. of 0.0721 Gm. KNO 3 in 100 Cc. water are diluted to 100 Cc. with cone. H 2 SO 4 ) and i Cc. solution to be tested each with i Cc. brucine solut. Make both up to 50 Cc., with cone. H 2 SO 4 , heat to 70 or 80 C., cool, and after solutions have acquired a sulphur-yellow color, compare intensities of colors in suitable test-tubes. The above normal solut. contains o.oi Mg. nitrogen from nitrates in i Cc. Lustgarten (CHLOROFORM). Add a solut. alpha- or beta-naphtol in potassa solut. to liquid and warm a blue color develops. Reaction also afforded by chloral. Lustgarten (!ODOFORM). i. Upon warming i or 2 drops of an iodoform solut. with a little phenol and KOH, a red ppt. forms, and which yields a red solut. with alcohol. 2. Dissolve o.i Gm. resorcin and a piece of sodium in 5 Cc. alcohol. Five drops of the resulting green solut. are mixed with an ethereal iodo- form solut., and the ether cautiously evaporated a cherry- red color results, destroyed by acids, but restorable by alkalies. Lustgarten (LEPRA-BACILLUS STAIN). Stain with aniline-water fuchsine or gentian- violet, and decolorize in i-% solut. chlo- rinated soda for some time, then rinse thoroughly in water. Tubercle bacilli are decolorized earlier than lepra bacilli. TESTS AND REAGENTS. 189, Lustgarten (NAPHTOLS). Alpha- and beta-naphtol dissolved in alcoholic potassa solut. and warmed with chloroform to 50^ C. yield clear, blue soluts. reddened by acids. See Wolffs test. Lustgarten (STAINING SYPHILIS BACILLI). Place sections in gentian-violet aniline water (see Koch-Ehrlich method) at the ordinary temperature for 12 to 24 hours, then for 2 hours at 40 C. Next transfer to absolute alcohol for a few minutes, then place for 10 seconds in a 1.5-% potassium-permanganate solut. and afterwards wash in sulphurous acid. If ground sub- stance of sections not completely decolorized, repeat second part of process, then dehydrate, clear, and mount in balsam. Lutesch (STAINING FLAGELLA). Mordant with freshly pre- pared solut. ferric acetate, to each 16 Cc. of which 5 to 10 drops acetic acid have been added, then wash in water, treat with 20-% acetic acid, again thoroughly wash, and finally stain with a hot solut. fuchsine or gentian- violet in aniline water. Luttke (FREE HYDROCHLORIC ACID IN GASTRIC JUICE). Yellow color of tropseolin OO is changed to red by free acid. See Rie gel's test and Boas' test. Lutz (MiCROCHEMiCAL REAGENT). Add NH 3 to a sat. solut. methyl green in 90-% alcohol until decolorization , then add acetic acid by drops till ppt. just redissolved. Macerate sec- tions in the solut., then transfer after a few minutes to water acidulated with acetic acid. Green color rapidly develops and becomes localized on elements just like fuchsine, but weaker; it is intensified on lightly warming sections. Reagent is adapted for use by artificial light. Lutz (TANNINS IN DRUGS). Copper sulphate, 2 Gm.; ammonia water, sufficient to just dissolve ppt. ; water, to make 100 Gm. Immerse drug in solut. for several hours, make sections, which wash well with water and imbed in glycerin-gelatin or Canada balsam. Tannins then appear dark-brown to black, and may be readily distinguished. Lutz-Unna (L/EPRA-BACILLUS DOUBLE STAIN). lodide-para- rosaniline method. Stair in heated dil. aniline-water gentian- violet solut. till section dark-blue violet, then carry from one to other of following, allowing a few minutes to each: Solut. KI, absolute alcohol containing 10- to 50-% HNO 3 , then pure TESTS AND REAGENTS. absolute alcohol. Repeat process several times (omitting KI at last) till section is only bluish-green or slate color, then clear in thymol or olive oil, and mount in balsam. Lux (FATTY OILS IN MINERAL OILS). In a paraffin bath kept at from 200 to 210 C., heat for 15 minutes two samples of oil contained in test-tubes, to one of which some of NaOH has been added, to the other a few fragments of metallic sodium. Even if specimen contains only 2% fatty oil, one or the other sam- ple, but generally both, will solidify and form a stiff mass. Lux (INDICATOR). The colorless alcoholic solut. of flavescin, an extract from oakwood, is turned yellow by alkalies, and decol- orized by acids. Lyon (MIXTURE FOR EXTRACTING STRYCHNINE AND BRUCINE). Three volumes ether, and i volume of a mixture of 88 Cc. chloroform, 12 Cc. alcohol, and 2 Cc. ammonia. Lythgoe (ANILINE ORANGE IN MILK). Mix 15 Cc. milk and 15 Cc. HC1 (sp. gr. i. 20) in a casserole, and gently shake to cause thorough mixing and breaking up of curd into coarse lumps if aniline orange present in milk, curd will be pink; if no color- ing matter present, curd will be white or yellowish. Mack (STRYCHNINE). With H 2 SO 4 and MnO 2 , strychnine gives a dark blue color, changing to violet, pink and yellow. MacLagan (COCAINE). Treat 50 Cc. of an approximately o.i-% solut. of a cocaine salt with 2 to 3 drops of NH 3 , and rub vigorously walls of the glass vessel with a glass rod pure cocaine separates out in crystals; a milky turbidity indicates presence of amorphous alkaloids (isatropyl-cocaine). MacMunn (!NDICAN). Modification of Hammarsten's reaction. Boil equal volumes urine and HC1 with a few drops HNO 3 , cool, and shake with chloroform last becomes violet, and shows indigo absorption bands. Mac William (ALBUMIN). A cone, aqueous solut. of salicyl-sul- phonic acid gives a white ppt. with albumin, globulin, myosin, and derived albumins. With albumoses, the ppt. dissolves on heating; peptones give no ppt. except in solut. saturated with ammonium sulphate. See Rock's test. Magini (STAIN FOR NERVOUS CENTRES). Improved Golgi's method. Harden cubes measuring 2 or 3 Cm. for 2 or 3 months in Muller's solut., then wash well with distilled water, TESTS AND REAGENTS. 191 and place in o.i- to i-% solut. ZnCl 2 . Change solut. for fresh every day for 7 to 10 days until it ceases to become more yellow than bichromate solut., then cut sections, wash . quickly with alcohol, imperfectly clear with creosote, and mount in dammar. Magnanini-Ciamician (SKATOL). See Ciamician-Magnanini. Magnier de la Source (URIC ACID). Triturate sediment from urine with water, add a few drops of bromine water, and evap- orate if uric acid is present residue is brick-red; on dissolv- ing it in KOH solut. a blue color results; with NH 3 solut. is purple. Mahomed (HEMOGLOBIN IN URINE). Dip blotting-paper in urine, dry over alcohol-lamp, drop on 2 drops tinct. guaiac, evap- orate off alcohol, and let i drop of ozonized ether fall on spot a blue color develops. Mahrenthal, Von- (STAIN). See Lee's osmic-acid and pyrogallol' stain. Maier (IODINE). A blue color develops on adding a very dilute solut. KI to a solut. of an iodide mixed with starch paste and H 2 SO 4 . Maier (TURPENTINE IN ESSENTIAL OILS). Note optical behavior of oils in a polarizing apparatus. See Am. Journ. Pharm., xxxvii, p. 338. Mai-Hilger (COLORING IN URINE). See Hilger-Mai. Maisch (CROTON OIL) Treat oils suspected to contain croton oil with alcoholic potassa solut., add water and HC1 to sepa- rated alkaline layer, and apply oil which separates to the skin a peculiar eruption results if croton oil present. Maisch (CURCUMA). See Maisch' 's test for turmeric. Also see Howie's test. Maisch (ESSENTIAL OILS). Note the appearance: (i) on letting i drop bromine fall upon 5 drops oil in a watch-glass; (2) on adding 5 drops ethereal solut. of bromine (ether 5, bromine i) to 5 drops oil. See Proc. Am. Pharm. Assoc., 1859, p. 338. Maisch (NITROBENZENE IN ALMOND OIL), i. Shake 2 or 3 Cc. of the oil with half its weight fused KOH a reddish-yellow color develops, which quickly changes to green; on adding water a ;green layer separates and turns red within twenty-four hours. 2. Dissolve i part oil in 12 of alcohol, add 9 KOH (? solut.) I9 2 TESTS AND REAGENTS. and evaporate to about 14 parts if oil pure, the residue is brownish-red, contains no crystals, and dissolves in water;, with nitro-benzene it is crystalline and insoluble in water. Maisch (QUININE). A voluminous crystalline but jelly-like ppt. is thrown down on adding a cone, solut. of an alkaline acetate to a solut. of quinine sulphate. Maisch (TURMERIC IN RHUBARB). Shake rhubarb powder for one or two minutes with absolute alcohol, and filter off liquid;, yellow filtrate is turned brown with cone, solut. of borax, and the color becomes only a little lighter on adding HC1, if tur- meric present. With pure rhubarb, the acid at once changes the color to light yellow. See Howie's test. Malassez (AMMONIA-CARMINE). See Ranvier's ammonia-carmine. Malerba (ACETONE). Fluids (such as urine) containing acetone are colored red by dimethyl-paraphenylene-diamine solut. The spectrum of the red solut. is similar to that of oxyhemo- globin. Mallet (MINERAL ACIDS IN VINEGAR). Add solut. sodium sali- cylate to vinegar if considerable mineral acid present, sali- cylic acid will ppt. out. With very small quantities of acids, however, no ppt. forms. Maly (BILIRUBIN). Bromine gives colors similar^to those af- forded by HNO 3 in Gmelin's test (q. v.). Maly (FREE HYDROCHLORIC ACID IN GASTRIC JUICE). Violet color of methylene blue is changed to green. Maly (URIC ACID). Dilute, faintly alkaline solut. of a urate remains clear on adding ammoniacal AgNO 3 . On adding an ammoniacal magnesia solut., however, a flocctilent or gelatin- ous ppt. forms. Mandel (PRECIPITANT FOR PROTEIDS). A 5-% solut. chromic acid forms a delicate reagent for albuminoids; a turbidity results with a dilution of i part albumin in 50,000 parts water. If solut. first acidulated with acetic or citric acid, the ppt. subsides very rapidly. A io-% solut. chromic acid may be used instead of nitric acid for Heller's zone reaction for albu- min. See also Zuelzer's test. Mandelin (ALKALOIDS). Solut. of i Gm. ammonium vanadate in 200 Cc. cone. H,SO 4 . Reagent yields brown, red, or green colors with alkaloids. TESTS AND REAGENTS. 193 Mandelin (STRYCHNINE). Mix little strychnine in a watch-glass with a few drops i-% solut. sodium vanadate in cone. H 2 SO 4 . On appearance of a dark color, tilt glass to allow fluid to run off residue develops a beautiful blue color, changing to ver- milion and reddish-yellow. On addition of a little alkali a permanent pink to purple color develops. Manfred! (GOLD METHOD). Treat fresh tissues with i-% solut. gold chloride for 30 minutes, then with 0.5-% oxalic-acid solut.; warm in water to 36 C., cool, and mount in glycerin. Mangin (CELLULOSE), i. Microscopical section is first mac- erated in a solut. of iodine, 0.5; potassium iodide, 1.5; water, 100 ; and H 2 SO 4 (2 volumes of cone, acid to i of water) is then added. Cellulose is indicated by a blue color. Section may be treated directly with one of the following solutions: (i) Zinc chloride, 20; iodine, 1.3; potassium iodide, 6.5; water, 10.5; or (2) with sat. calcium-chloride solut., 10; potassium iodide, 0.5; iodine, o.i; or (3) with cone, phosphoric acid, 25; potassium iodide, 0.5, and a few crystals of iodine. 2. Solut. of free iodine in iodic acid; section is dipped in water or alco- hol, then dried, a few drops reagent added, and the preparation washed in water. Cellulose is colored black. Mangini (ALKALOIDS). Potassium iodide, 3 parts; bismuth iodide, 16 parts; HC1, 3 parts. Reagent yields brown ppts. with solution of alkaloids. See Dragendorff's test. Above reagent has the advantage over the latter of not becoming tur- bid when mixed with water. Mann (ALBUMIN FIXATIVE). Shake i volume egg albumin with 10 volumes distilled water, and filter twice through same paper. Spread filtered liquid on clear slides, which then leave to drain and dry. Float sections to be mounted in warm water (40 C.), arrange on slides passed beneath them, place slides for 5 minutes on a stove heated to 35 C., and then treat with xylene and alcohol. Mann (OSMIC-ACID MIXTURE FOR NERVE CENTERS). Mix equal volumes i-% solut. osmic acid and sat. solut. mercuric chlo- ride in normal salt solut. (0.75-%). Mann (PICRO-TANNIN MIXTURES), i. Dissolve i part picric acid with (or without) i part tannin in 200 parts sat. solut. mercuric chloride in normal salt solut. (0.75-%). 2. Abso- 194 TESTS AND REAGENTS. lute alcohol, 100 Cc.; picric acid, 4 Gm. ; mercuric chloride, 15 Gm. ; tannin, 6 to 8 Gm. 3. Mercuric chloride, 12 Gm. ; so- dium chloride, 0.75 Gm.; picric acid, i Gm.; tannin, i Gm.; water, 1,000 Gm. Mann (WATER IN ALCOHOL, AIR, ETC.) Triturate i part molyb- dic acid with 2 parts citric acid, fuse, and when cool dis- solve in water. Saturate filter-paper with solut. and dry at 100 C. This blue paper becomes white on absorption of water when exposed to moist air, or when dipped into alcohol or ether containing water. Mann-Hefelmann (FLUORINE IN BEER). See Hefelmann- Mann. Manseau (CARBOLIC ACID). On addition of a few drops NH 3 to an alcoholic solut. of carbolic acid followed by adding tinc- . ture of iodine, the iodine disappears at first rapidly, then more slowly, and finally a greenish color is produced which remains even on heating or after the addition of HC1. Under similar conditions beechwood creoso e and guaiacol give a brownish- green color (the more phenol the creosote contains the more distinctly green is the color) ; thymol gives a brick-red ; resor- cin, a color like that of old cognac; naphtol, a citron-yellow; pyrocatechin,. a "catechu"; pyrogallol, a black; hydroqui- none, a reddish-brown; orcin, a violet; salicylic acid, a yel- lowish-green, passing to brown, with the formation of appt. In presence of NaOH or KOH a yellowish, not green, color is produced, with formation of a ppt. Mansier (CAMPHOR IN SPIRIT CAMPHOR). Add water to en- tirely ppt. camphor, then add cone, solut. chloral hydrate until camphor all redissolved. Quantity of solut. used is an index of the quantity of camphor present. Marchand (CINCHONA ALKALOIDS). Note effects of nascent oxygen from lead peroxide and H 2 SO 4 . See Am. Journ. Pharm., xvi, p. 198; xxx, p. 244. Marchand (IODINE). A rose to violet color with dry starch, ex- cess of HC1, and potassium bichromate results. Marchand (OLIVE OIL). Note color reactions with H 2 SO 4 . Marchand (ORGANIC MATTER IN WATER). Presence of sus- pended organic matter is revealed on placing the water in a flask surrounded by black paper in which two rectangular TESTS AND REAGENTS. 195 apertures are cut so as to be opposite, and passing a beam of light through the water. Marchand (STRYCHNINE). Triturate strychnine with H 2 SO 4 containing i% HNO 3 , and add lead peroxide a blue color develops which changes to violet, green, and yellow. Marechal (BILIARY PIGMENTS). Add 2 or 3 drops tincture of iodine to an acid or neutral urine if biliary pigments present an emerald-green color appears. See Smith's test. Mark (CHROMO-ACETO-OSMIC ACID). 7.5 parts 2-% chromic acid; 3.5 parts water; and i part glacial acetic acid. To 12 parts of this mixture add 8 parts i-% osmic-acid solution. Marm6 (ALKALOIDS). Add to a boiling, cone, solut. of potas- sium iodide (4 parts KI in 12 parts of water), cadmium iodide to saturation (2 parts), and mix this with an equal volume of a cold, sat. solut. of KI. The cone, solut. is permanent; a weak one decomposes upon standing. With solutions of alka- loids, this reagent yields white to yellowish ppts. See Dra- gendorff: " Ermittelung der Gifte " ; Hager: "Pharm. Praxis." Known also as Lepage's reagent. V erven modifies this by dis- solving potassium iodide, 10; cadmium iodide, 5; in distilled water, 100; five parts of the alkaloidal solut. slightly acidu- lated are shaken with i Cc. reagent. Marm (CADMIUM OR THALLIUM IN URINE). Potassium chlo- rate and HC1 are added to the solut., which is then concen- trated and electrolyzed. The metal deposited on the plati- num terminal is washed and spectroscopically examined. It is usually well to examine both cathode and anode. Marque (SPARTEINE). Sparteine sulphate warmed with one- third its weight of chromic acid yields a green color through reduction of the acid. The penetrating odor of cicutin is developed at the same time. Marquis (MORPHINE). Reagent is a mixture of 10 Cc. H 2 S0 4 and 10 drops of cone, oxymethylsulphonic-acid solution. Marsh (ARSENIC). Arseniuretted hydrogen (arsine) is produced from solutions of arsenates or arsenites (which must, however, be free from oxidizing agents) by pure zinc and dil. H 2 SO 4 . If gas is passed through a red-hot glass tube, metallic arsenic is deposited on the cold portion of the tube beyond the heated part. Upon igniting the arsine and holding a cold porcelain 196 TESTS AND REAGENTS. plate in the flame, metallic arsenic is deposited upon the plate, (Concerning further tests, distinction from antimony, and precautions to be observed in manipulation, see Frese- nius' "Qualitative Analysis," and Hager's "Pharm. Praxis." Davy's modification consists in the use of sodium amalgam instead of zinc and H 2 SO 4 . In Himmelmann's modification, zinc, iron, and cone, ammonium-chloride solut. are used. In Fleitmann's modification, zinc and caustic soda or potassa liberate the gas. Marsh (CHLORINE METHOD FOR BLEACHING SECTIONS). Gen- erate chlorine from potassium chlorate and HC1, and pass gas to bottom of vessel containing sections immersed in water. Marsh (DECALCIFICATION MIXTURE). Dissolve 15 Gm. pure chromic acid in 7 fl. oz. distilled water, and add 30 minims HNO 3 . Macerate objects in this for 3 or 4 weeks, changing fluid frequently. Marsh (GELATIN CEMENT FOR GLYCERIN MOUNTS). Soak oz. Nelson's gelatin in water until swollen, then pour off ex- cess of water, melt gelatin, and stir in 3 drops creosote. Use cement warm; when rings set quite hard and dry, paint over with solut. of 10 grains potassium bichromate in i fl. oz. water. Subsequent exposure to light renders the gelatin insoluble in water. Marsh (INDICATOR). An infusion of dahlia petals, containing 4 fl. dr. H 2 SO 4 and 2 grs. mercuric chloride to the pint, is neu- tralized with NH 3 . Alkalies turn the infusion green, and acids change the color to red. Martin (BENZOAZURIN STAIN). Immerse in a dil. aqueous solut. of benzoazurin for an hour or so, and wash out with 70-% alco- hol acidulated with 0.5 to i% HC1 (sp.gr. 1.16). Martin (NITRIC ACID). A solution of diphenylamine in H 2 SO 4 and water gives a blue to black color when a liquid containing nitric acid is added drop by drop. Martin (PEPTONES IN URINE). Ppt. proteids with ammonium sulphate, filter, and add to filtrate solut. copper sulphate and NaOH rose-red color develops. Martinet ti (PICRO-NIGROSINE STAIN). Pathological objects are stained for 2 or 3 hours or days in a sat. solut. of nigrosine in sat. alcoholic picric- acid solut. Then wash out in a mixture TESTS AND REAGENTS. 197 of i part formic acid with 2 parts alcohol until gray matter appears clearly differentiated from the white to the naked eye. Martinotti-Resegotti (SAFRANINE METHOD). Sections of alco- hol-fixed material, lightly stained with safranine are differen- tiated with a freshly prepared mixture of i part o.i-% aqueous solut. chromic acid with 9 parts absolute alcohol, followed by pure alcohol and bergamot oil. Elastic tissue is fixed by Mar- tinotti in a chromic liquid, washed, stained for 48 hours in Pfitzner's (5-%) safranine solut., again washed, dehydrated, cleared, and mounted in balsam. The elastic fibers are stained an intense black. Maschke (CREATININE). Neutralize a creatinine solut. with Na 2 CO 3 , or dissolve creatinine in a cold, sat. solut. Na 2 CO 3 , and add a few drops Fehling's solut. a white, amorphous, flocculent ppt. forms (more rapidly on heating). Maschke (GLUCOSE IN URINE). Dissolve crystallized sodium tungstate 30, in 30-% acetic acid, 75, and water, 120. A black deposit forms on adding to urine containing glucose one-third its volume of the above solut., filtering if necessary, adding half the volume of cone, soda solut. and a small fragment of basic bismuth nitrate, then boiling. Maschke (INDICATOR). An alcoholic solution of hematoxylin is changed from brownish-yellow to purplish- red by alkalies. Maschke (MOLYBDENUM). A blue color develops on placing 2 drops of H 2 SO 4 upon platinum foil, dusting upon the liquid a little of the powdered substance containing molybdenum, heating till vapors begin to escape, then cooling and breathing upon the foil. Maschke (NITROUS ACID IN WATER). Bluish color developed on adding 6 to 10 drops dil. acetic acid, followed by i or 2 drops of blue molybdic-acid solut., disappears within an hour if nitrous acid present. Maseau (PHENOL). On dissolving a few crystals phenol in i Cc. alcohol and adding a few crops NH S followed by an alcoholic solut. iodine, the latter is at first immediately decolorized, but later the solut. acquires a sea-green color, not destroyed by HC1 or heat, but destroyed by HNO 3 and H 2 SO 4 . For details see MERCK'S REPORT, x, p. 365. 198 TESTS AND REAGENTS. Masin (POTASSIO-MERCURIC IODIDE SOLUTION). Almost the same as Mayer's reagent (q. v.). Massart (HEMATOXYLIN-EOSINE). See Everard-Demoor-M as- sart. Masset (BILIARY MATTER). A grass-green color develops on adding 2 or 3 drops H 2 SO 4 and a crystal of potassium nitrite to 2 Cc. of urine containing biliary matter. See Gmelin's test. Massie (FIXED OILS). Note the color change on adding 5 Gm. HNO 3 to 10 Cc. of oil, and stirring with a glass rod for two min- utes. Then add i Gm. mercury, stir a few times during three or four minutes, and note the color reactions. Matthieu-Plessy (GLUCOSE; SUGAR; PYROGALLOL). Fuse to- gether 54 parts ammonium nitrate, 34 parts lead nitrate, and 21 parts lead hydroxide. This mixture melts at 105 C., and affords with glucose a cherry-red color ; with cane suga a yellowish-brown color; with pyrogallol a chrome-green color. Maugin (TEXTILE FABRICS). Reagent for the microscopical examination of textile fabrics is an ammoniacal ruthenium oxy chloride (ruthenium-red). Maule (LIGNIN). The section is soaked for about five minutes in a i-% solut. of KMnO 4 in dist. water, and then washed with water. The section is then soaked for 2 to 3 minutes in dilute HC1; after again washing in water, a drop of dilute ammonia solut. is added to the section, when the ligni- fied tissue becomes colored a deep red, the non-lignified re- maining clear and colorless. Maumene (DIFFERENTIATING OILS). The rise in temperature resulting when the oil and cone. H 2 SO 4 are mixed, is observed. Drying oils evolve much more heat than non-drying ones. Maumeng (GLUCOSE), i. Saturate white woolen threads with a 33-% zinc-chloride solut. and dry. When moistened with a solut. glucose and heated to 130 C., the threads are colored brown or black. 2. Heat glucose solut. with stannous chlo- ride a black-brown caramel-like ppt. forms. Maupy (CASTOR OIL IN BALSAM COPAIVA OR CROTON OIL). Heat 10 Gm. suspected balsam or oil in a silver dish with excess dry KOH, and stir until volatile oils dissipated. If castor oil was present, odors of sebacic acid and caprylic alcohol are TESTS AND REAGENTS. 199 noted, and two layers form, an upper resinous and a lower white fluid. The latter is boiled with 50 Gm. dist. water, and the solut. filtered. If any castor oil was present, sebacic acid separates on cooling. Mayencon-Bergeret (ARSENIC). On exposing mercuric-chloride paper to arseniuretted hydrogen, it is colored lemon-yellow to light brown. Mayer (AciD HEMALUM). See Mayer's Hemalum and Glyche- malum. Mayer (ACIDULATED ALCOHOL). Add 3 volumes of pure HC1 to 97 volumes of 90-% alcohol in which is dissolved a small quan- tity of picric acid. Mayer (ALBUMIN FIXATIVE FOR SLIDES). Shake well together 50 Cc. egg albumin, 50 Cc. glycerin, and i Gm. sodium salicyl- ate, then filter. Mayer (ALCOHOLIC CARMINE), i. Boil 100 Gm. alcohol with i or 2 drops HC1 and an excess of carmine, until a clear solution is obtained, taking care that the carmine remains in excess. 2. Boil carmine, 4 Gm., water, 15 Cc. and HC1, 30 drops, until the carmine is dissolved, then add 95 Cc. of 85-% alcohol and neutralize by adding NH 3 until the carmine begins to pre- cipitate. Mayer (ALKALOIDS). Solut. potassio-mercuric iodide. Dis- solve 13.546 mercuric chloride and 49.8 Gm. potassium iodide in water and dilute to i liter. With most alkaloids in slightly acid solutions reagent yields whitish ppts. It may also be used in quantitative determinations. Reagent is also known as Delf's, Planta's, Tanret's, and Winkler's reagents. Mayer (ALUMINIUM-CHLORIDE CARMINE). Dissolve i Gm. car- minic acid and 3 Gm. aluminium chloride in 200 Cc. water. Mayer (BERLIN-BLUE INJECTION). Add solut. of 10 Cc. tincture ferric chloride in 500 Cc. water to a solut. of 20 Gm. potassium ferrocyanide in 500 Cc. water, allow to stand for 12 hours, de- cant, wash deposit, for i or 2 days with distilled water, until washings come through dark blue, then dissolve the blue in about a liter water. Mayer (BLEACHING METHOD). Place specimens in 70- to 90-% alcohol and add potassium chlorate in crystals until the bot- tom of the vessel is covered. Then add a few drops HC1 and TESTS AND REAGENTS. warm if necessary until chlorine begins to be evolved. HNO S may be used instead of HC1, if desired. Mayer (BLUING SECTIONS). After staining with hematoxylin, treat sections for a few seconds with 0.5- to i-% potassium- acetate solut. Mayer (BORAX CARMINE). See Grenadier's alcoholic borax- carmine. Mayer (CARMALUM). Dissolve i Gm. carminic acid and 10 Gm. alum in 200 Cc. distilled water; decant or filter and add a few crystals thymol, 0.1% salicylic acid, or 0.5% sodium salicylate. A weaker solution contains 3 to 5 times as much alum and 5 times as much water. Mayer (COCHINEAL STAINS), i. Macerate i Gm. cochineal in coarse powder for several days in 8 to 10 Cc. of 70-% alcohol, stirring frequently. Filter before use. 2. Rub up in a mor- tar 5 Gm. finely powdered cochineal, 5 Gm. calcium chloride, and 0.5 Gm. aluminium chloride, then add 100 Cc. 50-% alco- hol and 8 drops HNO 3 (sp. gr. 1.2), heat to boiling-point, cool, leave standing for some days, with frequent agitation, and filter. In using these stains, prepare and wash out objects with alcohol of the same strength as that with which stain is prepared. Mayer (DESILICIFICATION PROCESS). Place objects in alcohol contained in a glass vessel coated internally with paraffin, then add hydrofluoric acid drop by drop until desilicification com- plete, avoiding the fumes. Mayer (HEMACALCIUM). Rub up together i Gm. hematein or the ammonium salt (see below) and i Gm. aluminium chlo- ride; add 10 Cc. glacial acetic acid and 600 Cc. 70-% alcohol, and finally 50 Gm. calcium chloride. Mayer (HEMALUM AND GLYCHEMALUM). Hemalum is prepared by dissolving i Gm. of hematein or the ammonium salt (pre- pared by dissolving i Gm. of hematoxylin with the aid of heat in 20 Cc. distilled water, filtering if necessary, then adding i Cc. NH 3 , sp. gr. 0.875, an d evaporating at the ordinary tem- perature) in 50 Cc. of 90-% alcohol, and adding to a solut. of 50 Gm. alum in a liter distilled water. Allow to cool and settle, filter if necessary, and add a crystal of thymol to pre- serve from mold. Mayer's acid hemalum is the same with the TESTS AND REAGENTS. 201 addition of 2% glacial acetic acid. Glychemalum is a mix- ture of 0.4 Gm. of hematein, 5 Gm. alum, 30 Gm. glycerin, and 70 Gm. distilled water. The hematein is first dissolved in a few drops glycerin. Mayer (INDIGO-CARMINE WITH CARMINE OR HEMATEIN). Dis- solve o.i Gm. indigo carmine in 50 Cc. distilled water or 5-% alum solut., and combine with 4 to 20 volumes carmalum or hemalum. Mayer (MUCICARMINE FOR STAINING Mucus). Heat for 2 min- utes, in a capsule over a small flame, i Gm. carmine with 0.5 Gm. aluminium chloride and 2 Cc. distilled water. Stir thor- oughly until mixture becomes dark and thick, then add a little 50-% alcohol to dissolve the warm mass, and make up with the alcohol to 100 Cc. Stand for 24 hours and filter. Mayer (MUCIHEMATEIN FOR STAINING Mucus). Mix 0.2 Gm. hematein with 40 Cc. glycerin, i Gm. aluminium chloride, and 60 Cc. water. Rub up hematein with a few drops glycerin first. An alcoholic solut. may be prepared by dissolving he- matein and aluminium chloride in 100 Cc. 70-% alcohol, with or without addition of 2 drops of HNO 3 . Mayer (PARACARMINE). Dissolve i Gm. carminic acid, 0.5 Gm. aluminium chloride, and 4 Gm. calcium chloride in 100 Cc. of 70-% alcohol. Allow to settle and filter. Mayer (PICRO-HYDROCHLORIC ACID). Mix 100 volumes distilled water with 5 volumes HNO 3 (of 25-% N 2 O 5 ), and saturate with picric acid. Mayer (PICRO-NITRIC ACID). Mix 100 volumes distilled water with 5 volumes HNO 3 (of 25-% N 2 O 5 ), and saturate mixture with picric acid. Mayer (PICRO-SULPHURIC ACID). Mix 100 volumes distilled water with 2 volumes H 2 SO 4 , and dissolve in the mixture 0.25% picric acid, or enough to saturate. Mayer (SHELLAC FIXATIVE). Heat powdered white shellac with crystallized carbolic acid till it dissolves, and filter warm solut. Or coat warm slides with a thin and even film of a moderately strong solut. brown shellac in absolute alcohol, and allow to dry. Sections are arranged on the dry film and gently pressed down on it, then exposed to vapor of ether. See Giesbrecht's method. 202 TESTS AND REAGENTS. Mayrhofer-Donath (GLYCERIN). See Donath-Mayrhofer. Maysel (BISMARCK-BROWN STAIN). Dissolve dye in acetic acid. According to Lee, solut. does not give a permanent stain. Mazzara (GLUCOSE). A green ppt. forms on heating the liquid with nickel chloride in presence of a little KOH. McClellan Forney (ALCOHOL AND TURPENTINE IN ESSENTIAL OILS). Mix five drops of the oil with i drop iodine pentabro- mide. For details see Am. Journ. Pharm., 1882, p. 546. Mecke (ALKALOIDS AND GLUCOSIDES). Solut. of selenous acid i, in cone. H 2 SO 4 200, gives various color reactions with alkaloids and glucosides when used hot or cold, as follows: Aconitine, amorph cold, colorless, or yellowish; hot, light brownish- violet. Aconitine, cryst. cold or hot, colorless. Apomor- phine cold, dark bluish- violet ; hot, gradually dark-brown. Atr opine hot or cold, colorless or almost so. Brucine cold, yellowish-red; hot, lemon-yellow. Caffeine cold or hot, colorless. Cocaine cold, colorless; hot, reddish-yellow. Co- deine cold, blue, changing to emerald-green and olive; hot, steel-blue, then brown. Colchicine cold, lemon-yellow; hot, yellowish-brown. Coniine cold or hot, colorless. Delphi- nine cold, deep reddish-brown; hot, brown. Digitalin cold, yellow, then red, gradually fading; hot, bluish- violet, then brown. Morphine cold, blue, then bluish- or olive-green; hot, brown. Narceine cold, faint greenish-yellow, then vio- let; hot, dark- violet. Narcotine cold, greenish steel-blue, then cherry-red; hot, cherry-red. Nicotine cold or hot, yel- lowish. Papaverine cold, greenish steel-blue, then violet; hot, dark- violet. Physostigmine cold, brownish-yellow; hot, faint brownish-red. Picrotoxin cold, almost colorless; hot, yellowish-brown. Quinine cold, colorless; hot, light-brown. Solanine cold, reddish-yellow; hot, grayish-brown. Strych- nine cold or hot, colorless. Thebaine cold, deep orange, gradually paling; hot, dark-brown. Veratrine cold, lemon- yellow then olive-green; hot, brownish- violet. Medicus (SALICYLIC ACID IN MILK). Add NaOH to the milk, and shake out fat with ether. Acidulate with HC1, and shake out again with ether, which removes the salicylic acid, then readily recognized by ferric chloride and other usual reactions. TESTS AND REAGENTS. 203 Mehu (ALBUMIN). In applying this test add i Cc. reagent (phe- nol i, acetic acid i, 90-% alcohol 2) to 10 Cc. liquid, after add- ing 5 Cc. of crude HNO 3 ; then shake well and allow to deposit. The acid may be advantageously replaced by 5 Cc. of sat. sodium-sulphate solut. A flocculent ppt. is thrown down. Mein (ABSINTHIN). Dissolves in H 2 SO 4 with a brownish color, which soon turns greenish-blue and becomes dark-blue on . adding water. Melassez (SOLUTION FOR PREPARING TEICHMANN'S HEMIN CRYSTALS). Fluid having the specific gravity of blood (1.050 to 1.057) ; consists of 3.75 parts mucilage of acacia, 1.875 parts sodium sulphate, 1.03 parts sodium chloride, and 100 parts water. Meldola (NITROUS ACID). A solut. of 0.5 Gm. para-amidoben- zene-azodimethyl aniline in i liter of dil. HC1. A few drops added to fluid to be examined, followed by a few drops HC1 and subsequently by NH 3 , develops a blue color in presence of nitrites; reagent keeps well for an indefinite period, contrast- ing in this respect favorably with Griess phenylenediamine solut. Melzer (ALKALOIDS, GLUCOSIDES, ETC.). Add i drop 20-% solut. benzaldehyde (in absolute alcohol) to trace of substance in watch-glass standing on white paper, and then add i drop cone. H 2 SO 4 . Following color reactions are obtained: Picro- toxin violet-red, first seen as bands of color, on adding water color disappears ; colchicine and caniharidin no characteristic color, but simply yellow solution; digitalin unsightly yel- lowish-brown color, and the particles become brown; coniine, nicotine, brucine, strychnine, papaverine, narcotine, atr opine, hyoscyamine, narceine, cocaine, and aconitine (in small quantity) no characteristic reactions. With considerable aconitine results like those of digitalin are obtained: veratrinc color like that given by H 2 SO 4 alone; codeine yellowish to blood- red color; thebaine particles present appearance of dark- brown specks; delphinine reddish-brown striae; emetine small traces no characteristic reaction, but large traces dark- brown striae; apomorphinc almost no color; morphine red or yellowish-red striae or colors. 204 TESTS AND REAGENTS. Mene (PHENOL). Bromine water gives a yellowish-white ppt. with carbolic acid. Merck (OPIUM). Treat with KOH solution and shake with ether, then dip a strip of filter paper into ethereal solut., moisten with HC1, and expose to vapor of boiling water. The paper should then turn red. Merget (MERCURY). i. Expose a strip of filtering paper moistened with ammoniacal silver-nitrate solut. and dried, to mercury vapor, which produces a black stain. 2. Dip a copper wire in the liquid containing mercury, dry with filter- paper, and wrap up in tissue paper moistened with ammon- iacal silver-nitrate solut. The mercury produces a black stain in this case also. 3. A piece of gold-foil upon which metallic mercury has been ppt. by stannous chloride from urine con- taining corrosive sublimate, is wrapped up first in tissue paper, and then in filter-paper that had previously been saturated with an ammoniacal silver solut. and dried. If mercury pres- ent a brown color develops in a few minutes on the inside of the filter-paper. To detect presence of mercurial vapor, lines are drawn on filter-paper with a glass rod moistened with an ammoniacal silver-nitrate solut. These are darkened by mer- curial vapor. Merget (MOISTURE). Test depends upon the use of salts which, like palladious chloride and mercurous chloride, show different colors when moist or dry. See Mann's test. Merget (TEST-PAPER FOR CARBON MONOXIDE, OZONE, ETC.). Paper impregnated with palladious-chloride solut. (contain- ing 5% metallic Pd) gives a black color with carbon monox- ide, H 2 S, ozone, methane, ethane, and illuminating gas. Merkel (CHROMIC ACID AND PLATINIC CHLORIDE). Mix equal volumes of i : 400 solut. chromic acid and i : 400 solut. platinic chloride. Objects are left in this for several hours or days to harden, then washed in 50- to 70-% alcohol. Merkel (FIXING SOLUTION). Chromic-acid solut. 0.25-%, i part, platinum-chloride solut. 0.25-%, i part. The solut. takes a long time to act, but the preparations stain well. Mermet (CARBONIC OXIDE). The following solutions must be freshly prepared: a. Silver nitrate 2 or 3 Gm., water 1,000 Cc. 6. A few drops HNO 3 (free from HC1 or chloride) added TESTS AND REAGENTS. 205 to i liter boiling water, then permanganate solut. added until permanent red color. In this, after cooling, i Gm. perman- ganate is dissolved. Reagent is prepared by mixing 20 Cc. a with i Cc. b and i Cc. HNO 3 , and diluting with distilled water to 50 Cc. Reagent is decolorized by CO and by H 2 S. Mermet (SULPHOCARBONATES). Diluted (almost colorless) am- moniacal solut. nickel sulphate or chloride gives a currant-red color with sulpho- carbonates. Merz (FIXED OILS). On mixing an adulterated oil with an equal volume pure oil and gently shaking, the mixture appears streaky. Merz (OLIVE OIL). One of two samples of olive oil is heated to 250 C. The heated sample, if pure, will appear much paler than the other. Merz (PHOSPHORIC ACID). Place a drop of liquid containing free phosphoric acid (or a little of dry substance mixed with H 2 SO 4 ) in a loop of platinum wire, and hold close to lower part of a hydrogen flame latter is colored green. Merz (TURPENTINE IN ESSENTIAL OILS). Pure oils become milky on shaking with an equal volume poppy-seed oil, but remain clear if they contain turpentine. Mesnard (ALBUMINS). Treat with glycerin containing sugar, and expose to fumes from cone. HC1. Messinger (ACETONE). Solutions containing acetone yield iodo- form on treatment with iodine and NaOH. For quantitative estimation, either the iodoform is weighed (Kramer), or the excess of iodine titrated (Messinger). Metzger (COCAINE). Dil. aqueous solutions of cocaine salts after acidulating with HC1 yield orange-yellow ppts. with potassium chromate. Meyer (COD-LIVER OIL). Pure cod-liver oil when shaken with Y 1 ^ its volume of a mixture of HNO 3 and H 2 SO 4 (i : i), is first colored rose-red, then lemon-yellow. Other fish oils either do not exhibit the color so clearly, or yield a brownish- violet color. Meyer (FURFUROL IN GLACIAL ACETIC ACID). Add a few drops solut. AgNO 3 and warm on water-bath for J hour if furfurol present, metallic Ag. pptd. A trace of furfurol does not, however, give the reaction. 206 TEST'S AND REAGENTS. Meyer (SALICYLIC VINEGAR). A solut. of i part salicylic acid in 100 parts pale-yellow pyroligneous acid (sp. gr. 1.04). For preserving various larvae, hydras, nematodes, etc., add i vol- ume salicylic vinegar to 10 volumes dil. glycerin (glycerin i vol., water 2 vols.). For infusoria the glycerin should be more dilute ( i to 4 of water). Meyer (THIOPHENE). Thiophene and its homologues yield a blue color with a solut. of isatin in cone. H 2 SO 4 . Mezger (COCAINE). See Metzger's test. Mialhe (CRUCIFEROUS OILS). Saponify cruciferous oils with potassa solut. and filter. On adding AgNO 8 to filtrate, latter acquires a black color. Michailow (PROTEIDS). Add ferrous sulphate to solut. of sub- stance, and overlay on cone. H 2 SO 4 . On adding very little HNO 3 the familiar reddish-brown zone develops, as well as a blood-red color, if proteids present. Millard (ALBUMIN IN URINE). Overlay urine on a mixture of phenol (95-%) 2 fl. dr.; acetic acid, 7 fl. dr.; and KOH solut. 22 fl. dr. a ppt. forms. "Millar d (PODOPHYLLUM RESIN), i. Resin of Indian podo- phyllum (P. emodi) gives an orange-red color when particles are sprinkled on cone. H 2 SO 4 placed* on a white surface; Amer- ican podophyllum (P. peltatum) gives a yellow to brown color according to quantity used. 2. Add 3 Cc. dil. alcohol (sp. gr. 0.920) and 0.5 Cc. potassa solut. (B.P.) to 0.4 Gm. resin in a test-tube and rotate latter gently with Indian resin the mix- ture forms a semi-solid gelatinous mass in a few seconds. It may be necessary to heat mixture to boiling-point and to cool before gelatinization takes place. American resin, similarly treated, does not gelatinize, even after some days. Miller (INDICATOR), Tropaeolin, or methyl-orange. Changed by mineral acids from yellow to crimson; indifferent to CO 2 and H 2 S. Miller, Von- (HYDROCHLORIC ACID IN GASTRIC JUICE). See Luttke's test. Million (LINSEED OIL IN OLIVE OIL). Mix 40 Gm. olive oil with 60 Gm. of a 20-% KOH solut. in 70-% alcohol, and heat on water-bath until alcohol has evaporated. Dissolve result- ing soap in warm water, separate fatty acids by adding dilute TESTS AND REAGENTS. 207 HC1, and dissolve in 20 Cc. 90-% alcohol. If, to this solut., after heating to 90 C., 2 Cc. of 3-% alcoholic AgNO 3 solut. are added, a brown color results, if linseed oil present. Million. Modification, of Bechi's test (q. v.). Millon (ALBUMINS AND PHENOLS). Dissolve mercury in an equal weight cold fuming HNO 3 (sp. gr. 1.4), then apply moderate heat, and dilute solut. with two volumes water. Reagent contains mercurous and mercuric nitrates, as well as free nitric and nitrous acids. Albumins yield a brick-red ppt. with reagent, particularly on warming. Similar reactions also given by all compounds of the aromatic series containing one hydroxyl or methoxyl group; a second hydroxyl or a nitro group in the ring changes the reaction (Nickel). Thus resor- cin yields a yellow, hydroquinone an orange, and pyrogallol a brown, color. Tannin and guaiacol yield red, eugenol and vanillin a violet, color. Kintschgen-GintV s modification: Add a little potassium nitrate to a solut. of mercuric nitrate, and add the necessary quantity of HNO 3 just before using. The potassium nitrate must be freed from any carbonate it may contain (by treatment with nitrous acid). See also Gallois', Hoffmann's, Almen's, and Plugge's tests. Millon (PARAOXYPHENYLACETIC ACID). Boil solut. with mer- curic nitrite and potassium nitrite if paraoxyphenylacetic acid present an intense red color develops. Millon (SALICYLIC ACID). A io-% mercuric-nitrate solution in diluted HNO 3 yields an intensely red color with salicylic acid. Minot (MACERATION METHOD FOR EPITHELIUM). Macerate embryos for several days in o.6-% salt solut., containing 0.1% thymol. Minovici (PICROTOXIN). Add 2 drops H 2 SO 4 to substance or to 2 or 3 drops of dil. solut. of latter, and a minute later add i drop of 20-% alcoholic solut. anisic aldehyde. Picrotoxin in sub- stance gives with the H 2 SO 4 a saffron color, and on adding the anisic aldehyde the particles are surrounded by an indigo- violet zone gradually changing to blue. On heating on water- bath to 80 C., a i : 1000 solut. gives a deep-red color; a i : 1500 solut. gives a still visible reddish- violet to pale-red. Miquel (CULTURE SOLUTION). Peptone, 20; sodium chloride, 5; wood ash, o.i; water, 1000. 208 TESTS AND REAGENTS. Mitrophanow (GOLD PROCESS FOR PRICKLE-CELLS AND INTER- CELLULAR CANALS). Wash the tail of an axolotl larva with distilled water, place for -an hour in a watch-glassful of 0.25-% solut. of gold chloride containing i drop HC1; wash, and re- duce in a mixture of i part formic acid with 6 parts water. Mitrophanow (MACERATION METHOD FOR EPITHELIUM). Fix the embryo for 15 minutes in 3-% HNO 3 ; then place for an hour in a mixture of alcohol, i volume, and water, 2 volumes, and finally treat with stronger alcohol for 24 hours to sepa- rate the epidermis. Mitscherlich (PHOSPHORUS). Acidulate aqueous liquid with H 2 SO 4 and distil, conducting vapors through a glass tube sur- rounded by a condenser. In a dark room, a luminosity is ob- served. If alcohol, ether, or oil turpentine present, lumi- nosity does not appear. Salts of mercury and iodine, and metallic sulphides also, interfere with luminosity. Mobin (MACERATING MEDIA), i. i part sea- water with 4 to 6 parts 0.5-% solut. potassium bichromate. 2. Sea-water containing 0.25% chromic acid, 0.1% osmic acid, and 0.1% acetic acid. Lamellibranchiata should be macerated in No. 2 for several days. Moddermann (AMMONIA). A very dilute solut. copper sulphate becomes turbid on adding NH 3 . Moer, van de- (CYTISINE). A 0.5-% solut. ferric chloride and 0.05-% solut. H 2 O 2 gives first a red, then blue color with cytisine. Moerner (ACETONE). Urine containing acetone, heated with a little of KI solut. and excess of ferric chloride yields intensely irritating vapors. Moers (ACETANILID; CITROPHEN; EXALGIN; METHACETIN; PHE- NACETIN). On adding a trace of one of these substances to i Cc. NaOH solut. followed by a drop of i : 1000 potassium- permanganate solut., a violet color develops, passing through blue and green; on adding excess of H 2 SO 4 , color changes to red and slowly disappears. With citrophen color changes through violet, blue, and green so rapidly that only the last is generally observed. With centi- or deci-normal solut. NaOH color changes are immediate with citrophen, phenacetin, and methacetin; after a time with acetanilid and exalgin. If TESTS AND REAGENTS. 209 Na 2 CO 3 used instead of NaOH, citrophen reacts at once; phenacetin and methacetin slowly; acetanilid and exalgin, not at all. With NaHCO 3 citrophen alone reacts, color being reddish-brown, changed by acids to violet. In acid solut., citrophen alone gives color reaction. Mohler (TARTARIC ACID). If a little tartaric acid or a tartrate be heated with a few drops solut. of resorcin i in cone. H 2 SO 4 100, until H 2 SO 4 vapors develop, the fluid acquires a fine wine-red color; the smallest trace of tartaric acid is suffi- cient. Mohr (ANTIMONOUS ACID). Dissolve the acid, or any of its compounds, in an aqueous solut. tartaric acid, neutralize ex- cess of acid with Na 2 CO 3 , then add a cold sat. solut. NaHC0 3 in the proportion of 10 Cc. to each o.i Gm. of Sb 2 O 3 . The clear solut. is titrated with decinormal iodine with starch indicator. The titration must be conducted immediately the solution of bicarbonate has been added, i Cc. decinormal iodine = 0.006 Gm. antimony. Mohr (CHLORIDES). This is the familiar volumetric process with decinormal silver nitrate, using potassium chromate as indicator. Mohr (FREE MINERAL ACIDS), i. Add a few drops of po- tassium-sulphocyanide solut. to a light-yellow solut. ferric acetate, free from alkaline acetates. Traces of mineral acid turn the mixture blood-red, but the color disappears on add- ing excess of sodium acetate. 2. KI starch paste, with a light-yellow solut. of ferric acetate, is turned red by traces of mineral acid. 3. On adding cane sugar to a solut. contain- ing H 2 SO 4 , and evaporating to dryness on a water-bath, a blackened residue is left. Mohr (GLUCOSE). See Moore's test. Mohr (HYDROCHLORIC ACID IN GASTRIC JUICE). 20 Cc. io-% potassium-sulphocyanate solut. with 5 Cc. 5-% ferric-acetate solut. HC1, with this reagent, yields a cherry-red color with a brownish tinge; much acid causes a chestnut-brown color. Also known as Rheoctis test. Mohr (NITRO-GLYCERIN). A purple to dark-green color develops on extracting with ether or chloroform, mixing with a few drops of aniline, evaporating, and adding a few drops H 2 SO 4 . 210 TESTS AND REAGENTS. Mohr (POTASSIUM SALTS). A sat. solut. of potassium and so- dium acid tartrates precipitates potassium salts from neutral solutions. Mohr (SOLUTION). The potassium-permanganate solut. gener- ally used in volumetric analysis. Moleschott (POTASSA AND SODA SOLUTIONS). Strong solutions (35- to 5-%) ai> e applied to the tissues on slides, and the alkali neutralized by adding acetic acid before mounting. See Gage's preservative. Moleschott (CHOLESTERIN). On allowing H 2 SO 4 to come in contact with substance under the microscope, the plates lose their form, and their margins become colored carmine-red, changed to violet on adding aqueous solut. iodine. Moleschott-Piso Bonne (SODIUM CHLORIDE AND ALCOHOL). Mix 5 volumes io-% salt solution with i volume absolute alcohol. Molher (REAGENT). See Gayon-Ganon-Molher's test. Molisch (CARBOHYDRATES). to i Cc. of solut. to be tested is shaken with 2 drops 15- to 20-% alcoholic solut. of alpha- naphtol or thymol. Upon adding an equal volume cone. H 2 SO 4 , a violet color ensues (furfurol reaction) in presence of carbohydrates (and various other substances). Addition of water causes a bluish- violet ppt., soluble in alcohol, ether, or potassa lye, with yellow color. Molisch (INDICAN IN PLANTS). Boil plant fragments \ minute with dil. NH 3 (2NH 3 + 98 water), filter, cool, and shake out with chloroform. Carry out similar process using 2-% HC1. If indican present, chloroform layer in one or both cases ac- quires a blue or violet color. Molisch (WOOD PULP). To a 20-% solut. of thymol in absolute alcohol, add water until no more thymol separates. Set aside solution for some hours with excess of potassium chlorate, then filter. Paper made with wood pulp moistened with this solu- tion gives a bright-blue color on the addition of a drop of cone. HC1. Monier (ALBUMIN), i. On adding albumin to a starch solut. colored blue by a few drops tincture iodine, the color is dis- charged. 2. Add a few drops iodine solut. to a solut. con- taining albumin, and heat a colorless coagulum forms. TESTS AND REAGENTS. 211 Monsel (SOLUTION). Solut. iron subsulphate. Moore (ANISE-OIL IMBEDDING PROCESS). Sections from ma- terial frozen and cut in anise oil are transferred direct into Canada balsam, without previous treatment with alcohol. Moore (GLUCOSE AND SUGAR IN URINE). Heat glucose solu- tions or diabetic urine with potassa a brown color ensues, and, after acidifying, odor of caramel supervenes. Also known as Mohr's or Pelouze's test. See also Heller's test. Moore (STAIN FOR BLOOD). Stain for 3 minutes in an alcoholic solut. eosine (i : 200), wash, and stain for 2 minutes in a i-% aqueous solut. of methyl green. Red corpuscles appear red; nuclei and white corpuscles bluish-green. Moore-Heller (GLUCOSE). Like Moore's test (q. v.). Morax (STAINING FLAGELLA). See Nicholle-Morax's method. Morgan (MERCURY). A silvery stain appears on placing 2 drops of the liquid on a piece of bright copper, and adding strong KI solut. Morpurgo (NITROBENZENE). Carefully heat to boiling in a porce- lain dish 2 drops liquefied phenol, 3 drops water, and a small piece KOH, then add liquid to be examined. On prolonged boiling a crimson ring appears at margin of liquid. If satur. solut. chlorinated lime be added, ring becomes emerald-green. To detect nitrobenzene in soap, dissolve latter in water, mix with excess milk-of-lime, extract with ether, and proceed as above. Morpurgo (SUCROL OR DULCIN IN BEVERAGES). Add to li- quid^ of its weight lead carbonate, and evaporate on water- bath to thick paste, which exhaust several times with alcohol. Evaporate alcoholic extract to dryness, and exhaust residue with ether. Pure sucrol or dulcin may be recognized on evap- orating ether by (i) physical properties and sweet taste; (2) by heating a short time with 2 drops phenol and 2 drops cone. H 2 SO 4 , adding a few Cc. water, and allowing a little NH 3 or NaOH to flow on cold mixture in a test-tube, when a blue or violet-blue zone forms. Morrell (LINSEED OIL). Pure oil is colored sea-green to green- ish-yellow on mixing 10 parts by weight with 3 of crude HNO 3 and allowing to stand for a time. Adulterated oil assumes a light-yellow color. 212 TESTS AND REAGENTS. Morson (CREOSOTE: PHENOL). Creosote is insoluble in glycerin; phenol is soluble. Morton (ARSENIC). Solut. is placed in an apparatus similar to Doebereiner's lamp and an electric current passed through to decompose the water, thus replacing the Zn and H 2 SO 4 . Motten-Lindemann (ALKALOIDS ; SACCHARIN). See Lindemann- Motten. Mueller (ACETANILID [ANTIPEBRIN] IN URINE). Boil urine with J volume HC1, cool, add a few Cc. 3-% solut. phenol, and a drop solut. chromic acid (or, calcium- or ferric chloride) a red color develops, turned blue by NH 3 (paramido-phenol reaction). Mueller (BERLIN BLUE FOR INJECTIONS). Ppt. a cone, solut. of Berlin blue by means of 90-% alcohol. The ppt. is very finely divided, while the fluid is perfectly neutral and much easier to prepare than that of Be ale. Mueller (CAUSTIC SODA IN CARBONATE). In the presence of caustic soda, potassium permanganate solut. turns green. Mueller (CYSTIN). Dissolve cystin (from the urine sediment) in warm potassa lye, dilute solut. v/ith water, and add sodium nitroferricyanide a purple- violet color develops. Mueller (HARDENING FLUID). 2 Gm. potassium bichromate; i Gm. sodium sulphate; 100 Cc. water. This solution is some- times mixed with one-third its volume of 90-% alcohol, its hardening action being then much more rapid. Mueller (HYDROGEN SULPHIDE IN URINE), i. Pass current of air through urine and against filter-paper dipped in alkaline solut. lead acetate paper is blackened. 2. Overlay urine on a mixture of HC1 and paramidodimethylamine containing i or 2 drops dilute solut. Fe 2 Cl 6 a blue zone forms. Mueller (SILVER STAINING METHOD). Impregnate prepara- tions by immersion in the dark for 2 or 3 minutes in a i-% solut. AgNO 3 , then add to the liquid a small quantity of i-% solut. silver iodide dissolved by the aid of a little KI. After agitation in the mixture, wash the preparations with distilled water, and expose to light for 2 days in a i-% solut. AgNO 3 . Mueller-Ebstein (PYROCATECHIN). See Ebstein- Mueller. Muir (BISMUTH). A brownish-black ppt. is thrown down on heating with a solut. of stannous chloride, i , and tartaric acid, 3, in sufficient KOH solut. TESTS AND REAGENTS. 213 Mukerji (FREE PHOSPHORUS). Operation consists in evolving hydrogen phosphide, and observing the glow in a dark room. For details, see MERCK'S REPORT, ix, p. 561. Mulder (GLUCOSE). Heat diabetic urine, or solut. containing glucose, with a solut. of indigo in H 2 SO 4 , then carefully neu- tralize with Na 2 CO 3 the color changes through green into red, and finally yellow, from reduction of the indigo. On expos- ure to the air, the blue color is restored. According to Yogi's modification, litmus is used instead of indigo; Neumann- Wender's test (q. v.) is a methylene-blue solut. Mulder (XANTHOPROTEIN). Upon boiling an albuminous sub- stance with cone. HNO 3 , it is partially or completely dissolved, forming a yellow solut. Albumoses and peptones yield this color even in the cold. Upon supersaturating with NH 3 or fixed alkalies, color changes to orange-yellow. Mulliken-Scildder (METHYL ALCOHOL). Heat a spiral of light copper wire in upper part of a Bunsen flame (to oxidize it), and while red hot, dip into 3 Cc. alcoholic solut. in a test-tube. Repeat once or twice. Then add to solut. i drop 0.5-% solut. resorcin, and overlay mixture on cone. H 2 SO 4 . If methyl alco- hol is present, a rose-red zone forms. For details, see MERCK'S REPORT, vm, p. 164. Munk (HEMAPHEINIC URINE). Greenish rhubarb- and senna urines (a), and santonin urine (6), give following reactions: Alkalies (a) and (b) , red. Alkali carbonates (a) , immediate, permanent red; (6), red slowly forming and gradually disap- pearing. Zinc dust with (a), red developed by alkali is dis- charged, but with (b), not discharged. Baryta solut. or milk- of-lime (a), on shaking with excess, gives a colored ppt. and colorless filtrate; (b) gives a colorless ppt. but colored filtrate. Munk (SULPHOCYANIC ACID IN URINE). Acidify 200 Cc. urine with HNO 3 , add solut. AgNO 3 , filter, decompose filtrate with H 2 S, distil, add ferrous sulphide (containing iron oxide) and NaOH, warm, then add HC1 Prussian blue forms. Munson (CHLORAL-HYDRATE SOLUTION). A i-% solut. in water. Musculus (FERMENT PAPER FOR UREA). Decomposing urine is filtered, the filter washed, colored with curcuma, and pre- served as test-paper. When brought into contact with a urea- 214 TESTS AHD REAGENTS. solution, the attached ferment decomposes the urea, and the resulting ammonium carbonate changes the curcuma coloring matter to brown. Muter (FATTY OIL IN COPAIVA BALSAM). Saponify 3 or 4 Gm. balsam with 5 Gm. NaOH and 50 Cc. alcohol on water- bath, add sufficient water, and concentrate to 100 Cc. Then add dil. H 2 SO 4 to permanent turbidity, next add NaOH until just clear. Now evaporate to dryness under constant stirring, and exhaust residue with 3 portions of 70 Cc. each of ether- alcohol. The residue will now consist of Na 2 SO 4 only, if no fatty oil was present ; otherwise it will contain sodium oleate. Dissolve residue in warm water, acidulate with HC1, and cool. If balsam pure, only a few resinous flakes observed; if fatty oil was present, an oily layer forms. Mylius (BILIARY ACIDS). In this modification of Pettenkofer's reaction, one drop of furfurol solut. and i Cc. of cone, H 2 SO 4 are added to each Cc. of the alcoholic solut. of the biliary acid, cooling if necessary. The resulting red color is permanent for some time, changing gradually to violet. See also Udran- sky's modification of Pettenkofer's reaction. Nadler (MORPHINE), i. A greenish-blue color develops on making a liquid containing morphine strongly alkaline, and boiling with barely sufficient solut. copper ammonio-sul- phate to color it light blue. 2. A rose-red color develops on heating morphine with a few drops H 2 SO 4 diluted with half its volume water, cooling, adding NH 3 in excess, again cool- ing, and shaking with chloroform. Nagelvoort (PILOCARPINE NITRATE). Dissolve 0.005 Gm. to o.oi Gm. salt in 5 Cc. water, add a few drops NH 3 and shake out with 10 Cc. chloroform. When both fluids clear, draw off chloroform and evaporate. Mix residue with o.oi Gm. calo- mel by stirring with a glass rod characteristic black color reaction appears, even without blowing over mixture, because pilocarpine is very hygroscopic. Napier (WATER IN ETHER). Paper impregnated with cobalt chloride is changed from blue to rose-red. Naschold (DIFFERENTIATING ANILINE BLUE FROM INDIGO CARMINE). Boil with io-% soda lye and make acid with HC1 TESTS AND REAGENTS. 215 blue color which had disappeared is restored with aniline blue; with indigo carmine the liquid remains colorless. Naylor-Braithwaite (ARSENOUS ACID), a. Copper sulphate, 200 Gm.; water, 50 Cc. b. Sodium tartrate, 0.5 Gm.; caus- tic soda, 5 Gm. ; water, 50 Cc. Mix the two soluts. when required for use. Arsenous acid reduces this reagent. Neelsen (CARBOLFUCHSINE). Solut. for identifying tubercle bacilli in sputum is prepared by adding a cone, alcoholic fuch- sine-solut. to a 5-% aqueous carbolic-acid solut. (5 Gm. crys- tallized acid in 100 Cc. water, and i Gm. fuchsine, dissolved in 10 Gm. alcohol, added). Ehrlich's and ZiehVs carbolfuchsine solutions are similar. Neelsen (BACILLI). See Ziehl-Neelsen's method and solution. Neisser (GONOCOCCUS STAIN). Float preparation first on cone. alcoholic solut. eosine, which is then heated. Remove excess of eosine from cover-glass with blotting-paper, then place in a cone, alcoholic solut. methylene blue for 15 seconds, then . rinse in water. Neisser (SPORE STAIN). Stain in heated carbol-fuchsine, rapidly rinse in i-% aq. solut. H 2 SO 4 , double-stain in aque- ous or Loeffler's solut. methylene blue; or, stain in aniline- water methylene- violet solut., wash in i-% aqueous solut. H 2 SO 4 , and after-stain in acid brown. Neisser (STAINING METHOD FOR SPORE-BEARING BACILLI). Cover-glass preparations are immersed for 20 minutes in fuch- sine-aniline water (cone, alcoholic solut. of fuchsine, n Cc.; absolute alcohol, 10 Cc.; aniline water, 100 Cc.); then heat to 80 or 90 C.; next rinse in water, alcohol, or weak acid, according to the nature of the bacilli, counter-stain with aque- ous solut. methylene blue, rinse in water, dry and mount in balsam. Spores are stained red and the rest of the bacilli blue. Neisser-Bienstock (SPORE STAIN). Stain with heated aniline- water fuchsine, wash in HCl-alcohol, and double-stain with methylene blue. Spores are red; bacteria, blue. Nencki (!NDOL). HNO 3 containing nitrous acid gives with indol a red color or ppt. Reaction not afforded with skatol. See also Baeyer's test. Nessler (ALDEHYDE). Aldehydes, when treated with Nessler's ammonia reagent (q. v.) or with a solut. potassium-mercuric 216 TESTS AND REAGENTS. iodide and baryta water, yield a brownish-black ppt., differ- ing from the ppts. given by NH 3 in being insoluble in KCN. Nessler (AMMONIUM SALTS). Alkaline solut. of mercuric chlo- ride and potassium iodide gives with NH 3 as well as with am- monium salts a yellow to reddish-brown color or ppt. Rea- gent is prepared according to various formulas, as for instance, as follows: i. 50 Gm. KI are dissolved in 50 Cc. hot water and cone, mercuric-chloride solut. (20 to 25 Gm. mercuric chloride) added until the ppt. is permanent. After filtering, 150 Gm. KOH dissolved in 30 Cc. water are added, and the whole diluted to one liter. 5 Cc. of the mercuric-chloride solut. are now added, the resulting ppt. allowed to settle, and the clear liquid decanted (Kubel). 2. Dissolve 2 Gm. KI in 5 Gm. water; add 4 Gm. mercuric chloride, or so much that upon warming, a little of the ppit. remains undissolved. After cooling, dilute with 20 Gm. water, filter, and add 30 Cc. solut. of i part of KOH in 2 parts water. (Ludwig, Medicin. Chemie.) Nessler (CITRIC ACID IN WINE). Citric acid in wine points to probable adulteration with raspberry juice. The acid is separated as calcium citrate. Nessler (SULPHURIC ACID IN VINEGAR). Add 2- or 3% cane sugar to vinegar; dip a strip filter-paper in solut. and dry paper becomes brown to black. Nessler (TARTARIC ACID IN WINE). A crystalline ppt. forms on evaporating wine to syrupy consistency, extracting with alcohol, and adding solut. sodium- or potassium-acetate. Nessler (WiNE PIGMENTS). Solut. of 7 parts alum and 10 parts sodium acetate in 100 parts water. Nesteroffsky (GOLD PROCESS). Tissues impregnated with gold are treated with a drop of ammonium-sulphydrate solut. and the reduction finished with glycerin. Neubauer (ALBUMIN). Solut. albumin is pptd. by neutral and basic lead acetate, copper sulphate, mercuric chloride, and mercuric nitrate. Ppts. are partly soluble in excess of rea- gent or albumin solut, Neubauer (AMMONIA IN URINE). On adding milk-of-lime, am- moniacal odors are evolved and detected by litmus paper. TESTS AND REAGENTS. 217 Neubauer (BILIARY ACIDS). Modification of Pettenkofer's test. A few drops urine are evaporated to dryness on the water-bath, a drop of i : 500 sugar solut. and a drop cone. H 2 SO 4 added, and the whole heated on a water-bath if biliary acids pres- ent, a violet-red color appears at the edge. Neubauer (CHLOROFORM IN URINE). Pass a current of air through urine, then through a porcelain tube heated to red- ness, and finally through a AgNO 3 solution. If chloroform present in the urine silver chloride is pptd. Neubauer (HYDROQUINONE IN URINE). Urine containing hy- droquinone (after taking a phenol or benzol), darkens on ex- posure to air, when made alkaline. Neubauer (PHENOL). Add phenol to NH 3 , then add solut. chlorinated soda, and heat a blue color develops. Neubauer (PYROCATECHIN IN URINE). Add i drop cone, solut. tartaric acid and then some NH 3 to a dil. solut. Fe 2 Cl 6 ; on dropping in this solut. urine containing pyrocatechin, a violet color develops, turned yellowish-green by acetic acid, and violet again by NH 3 . Neubauer (URIC ACID). On boiling uric acid or potassium urate with ferric chloride, latter is reduced to ferrous salt, and urea and oxalic acid are formed. Neubauer- Fresenius (PHOSPHORUS). See Fresenius-Neubauer. Neuberg (SucciNic ACID). Add NH 3 to the solut. to be exam- ined (if a succinate is present add also ammonium phosphate) , evaporate to about i Cc., add i Gm. zinc dust, and heat. When the excess of NH 3 is evaporated dip a pine-splint moist- ened with HC1 into the test-tube the wood is colored red if succinic acid present. Reaction is positive so long as no other substances capable of giving the pyrrol reaction present. 0.0006 Gm. succinic acid thus detected. Neukomm (BILIARY PIGMENTS). Extract with alcohol, evap- orate to small bulk, place i drop on porcelain plate, add i drop dil. H 2 SO 4 and a trace sugar solut., and heat gently a violet color develops. Neumann- Wender (ALKALOIDS). Solut. 5 drops furfurol in 10 Cc. of pure cone. H 2 SO 4 . See also Weppen's veratrine reac- tion. 2i8 TESTS AND REAGENTS. Neumann- Wen der (GLUCOSE IN URINE), i Cc. dil. urine (1:10) is treated with i Cc. each of 1:1000 methylene-blue solut. and normal KOH solut. and boiled for a minute. Com- plete decolorization indicates that sugar was present in the urine. See also Mulder's test. Nias (CLEANING SLIDES AND COVERS). Boil with solution of washing soda, and rinse. Nicholle-Morax (STAINING FLAGELLA). Dry films on cover- glasses without fixing in the flame, cover with mordant, heat for about 10 seconds, and when steam rises shake off mordant and rinse with water. Repeat process 3 or 4 times, stain with Ziehl-Neelsen's solution, then hold over a flame once or twice for about 15 seconds, and wash. Nicholson (NITRIC ACID). Evaporate solut. to dryness, mois- tening with i or 2 drops H 2 SO 4 , and add a trace brucine if nitric acid present, a red color develops. Nickel (COLOR REACTIONS OF CARBON COMPOUNDS). See Zeitsch. f. Anal. Chem., 1889, p. 244; also see Milton's reagent. Nickel (MINERAL ACIDS IN ORGANIC ACIDS). Wood is stained by phloroglucin only in the presence of the former, hence if 0.5% HC1 is present in vinegar, and phloroglucin added, a piece of pine wood or wood-pulp paper dipped into the solut. is quickly and distinctly stained on boiling the solution up once. Nickles (FIXED OILS). Oils are distinguished according as they are or are not emulsified by hydrated lime. For details see Am. Jour. Pharm., xxxvm, p. 299. Niessing (FIXING SOLUTIONS). Modifications of Hermann's mixture, which see. i. 5 volumes of io-% platinic-chloride solution, 20 of 2-% osmic acid, 5 of glacial acetic acid, and 50 of distilled water. 2. This is the same, except that the dis- tilled water is replaced by sat. aqueous solut. of mercuric chloride. Niggl (LIGNIN). Treat specimen first with aqueous solut. of indol for a few minutes, then with H 2 SO 4 (sp. gr. 1.2) a red color develops if lignin present. Nikiforow (CLEARING MIXTURE FOR CELLOIDIN SECTIONS). Equal parts of 95-% alcohol and chloroform. TESTS AND REAGENTS., 219 Nikitin (COPPER IN PRESERVED PEAS). Boil peas for 3 min- utes in io-% H 2 SO 4 if peas uncolored, they acquire a dark- brown color; if colored with a copper salt, they retain their light-green color. Nissen (GENTIAN VIOLET STAINING PROCESS). Same as Biz- zozero's method, except that the treatment with chromic acid is omitted. Nissl (FUCHSINE STAIN FOR NERVE CELLS). Fresh material in pieces measuring i Cc. are hardened in a chromic solution in 70-% alcohol for 2 days, then transferred to absolute alco- hol for 5 days, and afterwards cut. Stain the sections singly in a sat. solut. of fuchsine, warming in a deep watch-glass until vapors begin to be given off. Next plunge section into abso- lute alcohol for i or 2 minutes, then place on a slide, flood with clove oil, and when no more color is given off, drain and mount in balsam. Nissl (METHYLENE BLUE METHOD). Sections of fresh ma- terial hardened in 96-% alcohol, are warmed to 65 or 70 C. in a watch-glass containing a solut. of methylene blue, 3.75 parts, and Venice soap, 1.75 part, in distilled water, 1000 parts. When bubbles are given off place sections in a mix- ture of 10 parts aniline with 90 parts 96-% alcohol until color is no longer given off. Then dry on a slide with filter- paper, clear with cajeput oil, again dry, and finally treat with a few drops of benzin, and mount in benzin colophonium. Niviere- Hubert (FLUORINE IN WINE). Make wine slightly alkaline with ammonium carbonate, then precipitate any fluorides present, as calcium fluoride, with calcium chloride. After heating incinerated residues with silicic acid and H 2 SO 4 , fluorine is identified in the usual manner as silicium fluoride. Nobel (COPAIBA OR GURJUN OIL IN URINE). On adding HC1 to urine containing copaiba or Gurjun oil, a red color de- velops. Noel (BILIARY PIGMENTS). Apply a drop of HNO 3 , to filter- paper dipped in the liquid and dried a violet color, changing to red and yellow, develops. Noll (CORROSION METHOD). Treat pieces of sponge with Ja- velle water until all soft parts are dissolved, then cautiously treat with acetic acid to remove all pptd. matter; after pass- 220 TESTS AND REAGENTS. ing through successive alcohols and through clove oil, mount in balsam. Noll (SALICYLIC VINEGAR AND GUM MEDIUM). Mix equal vol- umes Meyer's salicylic vinegar (2) and Farrant's medium. This mixture never becomes turbid and does not dry up. It serves well for delicate Crustacea and their larva; also for hardened and stained preparations of Hydroids, small Me- dusae and other Ccelenterates. Noll (SOLUTION). Solut. sodium hypochlorite. Nowak-Kratschmer (ALKALOIDS). Color reactions are af- forded with syrupy phosphoric acid. Nylander (GLUCOSE). Dissolve 2 Gm. bismuth subnitrate and 4 Gm. Rochelle salt in ioo Gm. of 8-% NaOH solut. To 10 parts of solut. to be tested (diabetic urine), add i part reagent and boil a darkening due to reduction of bismuth salt, indi- cates glucose. Also known as Almen's solution. Nylander- Alme"n. See Almtn-Nylander. Oberdoerffer (ALCOHOL IN ESSENTIAL OILS). Expose oil under a bell-jar, together with a watch-glass containing platinum black, over which is a strip of moistened blue litmus paper. The paper is reddened by the acetic acid formed if alcohol present. Obermayer (!NDICAN IN URINE), i. Add to urine cone. HC1 containing ferric chloride, and shake out with chloroform, if indican present, chloroform turns blue from solution of in- digo formed. Excess of reagent does not affect reaction. See Hammarsteris test. 2. Treat urine with lead acetate and clear filtrate from the ppt. Shake with a 0.5-% solut. ferric chloride in fuming hydrochloric acid (sp. gr. 1.19). Upon extracting with chloroform, the latter is colored blue if indican was present. Obenneier. See Obermayer. Obermueller (CHOLESTERIN). If cholesterin is carefully melted over a naked flame with a few drops propionic anhydride, the melted mass on cooling turns violet, then blue, green, orange, carmine, and finally copper-red. Oglialoro (PICROTOXIN). i. Dissolve fragment in 2 Gm. HNO 3 (sp. gr. 1.4) and warm a yellowish-red mass remains, turned bright red by 2 Gm. KOH solut., and on warming, to TESTS AND REAGENTS. 221 color of old blood. 2. Mix a little picrotoxin with 4 to 5 Gm. cone. H 2 SO 4 latter is colored golden-yellow, then saffron yellow. On adding potassium bichromate a greenish-violet develops; on diluting with water, solut. is greenish-yellow. Ogston (CHLORAL HYDRATE). Addition of ammonium sulphy- drate to a solut. containing chloral hydrate causes a brown color, and on heating a red ppt. forms. Ohlmacher (FORMALDEHYDE STAINING). Formaldehyde 2- to 4-% is used as a mordant for tar colors. Tissues may be mor- danted separately by treatment for i minute or longer, or the formaldehyde may be added to the stain. Dissolve i Gm. fuchsine in 10 Cc. absolute alcohol, and add to 100 Cc. 4-% formaldehyde. Or, add sat. alcoholic solut. of gentian violet or methyl violet 5 B. to the formaldehyde in the proportion of i: 10. In the case of methylene blue, dissolve i Gm. in 100 Cc. formaldehyde solut. Sections stain in half a minute, and are said to resist alcohol much more than if formaldehyde were not used. Oliver (ALBUMIN AND SUGAR). Filter paper saturated with well known reagents for albumin and sugar in urine. For albumin: Picric and citric acids; sodium tungstate and citric acid; potassium-mercuric iodide and citric acid; potassium ferrocyanide and citric acid, separately. For sugar: Indigo carmine and sodium carbonate, separately. See Geissler's test. Oliver (BILIARY ACIDS). Dilute urine to sp. gr. 1,008, and mix 20 minims with 60 minims of a solut. of meat-peptone 30 grn., salicylic acid 4 grn., acetic acid 30 minims, and water 8 fl. oz. If biliary acid present, a ppt. forms. Oliver (GALLIC AND TANNIC ACIDS). Add 10 drops strong HNO 3 to salmon-red solut. obtained by adding i grain gallic acid to 90 minims NH 3 , and set aside for some time no ppt. forms, but color changes to deep red. Tannic acid similarly treated, yields a colored solut. with a flocculent ppt. insoluble in excess of acid, in a few moments. Oppitz (SILVER STAINING). Reduction is very rapidly effected by placing the preparations for 2 or 3 minutes in a 0.25- to 0.5-% solut. of tin chloride. 222 TESTS AND REAGENTS. Opwyrda (TURMERIC IN RHUBARB). An alcoholic solut. of boric acid affords a red color with turmeric, which changes to greenish-black on adding KOH. Orlow (PHENOLS). Uranium acetate gives a sharp reaction with pyrogallol, hydroquinone, pyrocatechin, gallic acid, sali- cylic acid, and morphine. Phenol, eugenol, cresol, resorcin, phloroglucin, alpha-naphtol, beta-naphtol, and guaiacol but a slight reaction. No reaction is obtained with thymol. Orlow-Horst (ALKALOIDS). Ammonium persulphate gives with cocaine a colorless ppt. in form of a viscid liquid solut. in excess of reagent. Strychnine affords a pulverulent ppt. In admixture with H 2 SO 4 , ammonium persulphate affords the following reactions: Chelidonine, yellow, changing to green and finally brown; ckelerytkrine , violet, changing to black; sanguinarine , dark-brown; corydaline , yellow, then dirty-green, finally dirty-yellow; morphine, pale-orange; co- deine, orange; narcotine, reddish-orange; papaverine, yellow; narceine, violet changing to blood-red, and finally yellow; apomorphine, green, changing to blue. Orlowski (ANALYTICAL REAGENT). Use ammonium thiosul- phate instead of hydrogen sulphide as a group reagent. See Journ. Chem. Soc. (Abstracts), 1884, p. 363. Orth (LITHIUM CARMINE). Digest 2.5 Gm. carmine in 100 Cc. sat. aqueous solut. of lithium carbonate (i Gm. in 70 Cc. dis- tilled water), and filter. Orth (METHYL-VIOLET STAIN). Soak sections in water, then place in solut. of i part aniline violet in 300 parts acetic acid. Do not wash, but simply drain, and mount in solut. of i part potassium acetate in 2 parts water. Oser-Kalmann (INDICATOR). The product of the action of po- tassium permanganate and sulphuric acid on gallic acid is fused with caustic potash. The red color of the compound thus obtained is changed to yellow by acids. O'Shaughnessy (OPIUM). On adding a ferric salt to a solut. containing opium, red iron meconate is formed. The color of this is not affected by alkaline solutions, whereas sulpho- cyanide of iron is decolorized when similarly treated. Ost (SUGAR). A solut. containing 23.5 Gm. copper sulphate, 250 Gm. sodium carbonate, and 100 Gm. potassium bicarbon- TESTS AND REAGENTS. 223 ate per liter is used for the determination of sugar. See also Soldaini's test. Oster (ARSENIC IN HYDROCHLORIC ACID). Boil the acid with pure tin-foil a brown stain is formed on the metal, if arsenic present. Ott (BILIRUBIN IN URINE). Improved Salkowsky's test. Make urine alkaline with sodium carbonate, and add CaCl 2 until no ppt. further forms. Filter off gelatinous ppt., wash well, and dissolve in alcohol by aid of HC1. On boiling, solut. ac- quires a green to blue if biliary pigment present ; otherwise no color forms. On adding HNO 3 , green solut. becomes blue, red, and finally violet. If much albumin or hemoglobin pres- ent, or- after taking certain remedies, e. g. salol, test for bili- rubin is inconclusive. Otto (ALCOHOL). Add to liquid an equal volume cone. H 2 SO 4 and a little sodium acetate if alcohol present, odor of acetic ether will be observed. Otto (ALKALOIDS). Solut. sodium tungstate containing some phosphoric acid, gives ppts. Otto (DIGITALIN). i. Dissolve digitalin in cone. H 2 SO 4 and add some bromine water a light-purple color develops. 2. Warm aqueous solut. with few drops solut. phospho- molybdic acid a fine green color develops, changed to blue by NH 3 . Otto (MORPHINE). With HC1, Fe 2 Cl 6 , and potassium fern- cyanide, morphine yields a ppt. of Prussian blue. Otto (PICROTOXIN). A solut. of the alkaloid in cone. H 2 SO 4 is colored reddish-brown at the zone of contact by a drop of potassium-bichromate solut.; upon mixing, the solut. is colored green. Otto (STRYCHNINE). Mix substance (e. g. evaporation residue of ethereal or alcoholic extract) with a few drops dil. solut. potassium bichromate. Dip a glass rod into this solut., and then draw it through cone. H 2 SO if strychnine present, blue streaks will appear. Otto (SUGAR). Modified Fehling's test. Solut. of i part copper sulphate and 3 parts tartaric acid, to which enough NaOH is added to just effect a clear solution. 224 TESTS AND REAGENTS. Otto-Stas (ALKALOIDS). Extract with alcohol containing tar- taric or oxalic acid, then use alcohol and ether. See Am. Journ. Pharm., 1874, p. 120. Oudemans (QUINAMINE). When a drop of liquid containing quinamine is overlaid on H 2 SO 4 containing a trace of HNO 3 , a chestnut-brown to orange-red color is produced, which changes to purple on adding water. Overbeck (COTTON IN WOOLLEN). Soak fabric in an aqueous solut. of alloxantin (i in 10), and after drying expose to NH 3 vapor and rinse in water. Woollen material is colored crimson, cotton remains white. Overbeck (IODINE). A blue color develops on passing a current of hyponitrous acid gas into the liquid, if the latter has previously been mixed with starch paste. Overton (BLEACHING OSMIC OBJECTS). Bleaching is com- pleted in a few minutes in a mixture of i part commercial hydrogen dioxide with'io to 25 parts 70-% alcohol. Overton (IODINE FIXING). Heat iodine in a test-tube till vapor is given off, then incline tube so that the vapor may flow over objects arranged on a slide. Afterwards warm slide to about 40 C. for 2 or 3 minutes, in order to drive off the iodine, prior to mounting or further treatment. Pacini (PRESERVATIVE SOLUTIONS). These are employed to preserve microscopic sections, i. i part mercuric chloride, 2 parts sodium chloride, 13 parts glycerin (25 Be".), and 113 parts of water; 2. i part mercuric chloride, 2 parts acetic acid, 43 parts glycerin (25 Be.), and 275 parts water. Pacquelin-Joly (PYROPHOSPHORIC ACID IN URINE). See Joly- Pacquelin. Pagel (PHOSPHORUS IN PHOSPHORIC ACID). A white opales- cence or ppt. forms upon warming acid with an equal volume mercuric-chloride solut. (i: 60) to about 180 C. Pagenstecher (HYDROCYANIC ACID). Filter-paper is soaked in freshly-prepared tincture guaiac (3- to 4-%), dried and moist- ened with copper-sulphate solut. (0.25-%). HCN colors the prepared paper blue. See also Schoenbein-Pagenstecher. Pain (SANTONIN). On heating a fragment of santonin with an alcoholic solut. of ethyl nitrate, and then adding a few drops TESTS AND REAGENTS. 225 KOH solut. to the hot liquid, a reddish-violet color develops. The reaction will readily detect o.ooi Gm. santonin. Pal (BLEACHING SOLUTION). Dissolve i Gm. each of oxalic acid and potassium sulphite in 200 Cc. distilled water. Pal (HEMATOXYLIN METHOD). Proceed at first as in Weigert's process for nerve fiber, omitting the copper bath, and stain in Pal's hematoxylin solution (see below) for 5 or 6 hours. Then wash sections in distilled water (containing a trace of lithium carbonate if the sections are not deep blue) , next treat for 1 5 to 30 seconds with a 0.25-% potassium permanganate solut., rinse in water, and decolorize in Pal's bleaching solution. (If black spots appear replace in the permanganate solut., again bleach, and wash dry for 15 minutes in water.) The gray substance of the sections is decolorized in a few seconds; the sections should then be well washed out, and may be double-stained with picro-carmine or acetic-acid carmine (see Schneider), Magdala red, or eosine. The nuclei may be stained with alum carmine. Finally dehydrate, clear, and mount. Pal (HEMATOXYLIN STAIN). Dissolve 0.75 Gm. hematoxylin in 90 Cc. distilled water and 10 Cc. absolute alcohol. Just before use add sat. solut. lithium carbonate in the proportion of 3 drops to each 10 Cc. of hematoxylin solution. See also Weigert. Pal-Exner (OsMic- ACID-METHOD). Spinal cord or brain in i-inch cubes is immersed in 0.5-% osmic-acid solut. for 2 days, the solution being changed each day; then wash in water, transfer to absolute alcohol, and imbed in celloidin or paraffin. Place sections as cut in glycerin, then wash in water, treat with potassium permanganate and Pal's solution, as in Pal's hematoxylin method, counter-stain with car- mine, dehydrate, clear, and mount in balsam. Paladino (PALLADIUM-IODIDE STAIN). Pieces of nerve fiber hardened in bichromate, chromic acid, or corrosive sublimate, and not more than 5 to 8 Mm. thick, are immersed for 2 days in a large quantity of o.i-% palladium-chloride solut. (pre- pared bv dissolving 10 Gm. of the salt in i liter of water, with the aid of 4 to 6 drops HC1, and diluting as required). Next treat for 24 hours with a i-% KI solut., dehydrate, imbed if 226 TESTS AND REAGENTS. necessary in paraffin by the chloroform method, and mount in balsam. Palm (ALKALOIDS), i. vSodium sulphantimonate gives milky to yellow or red-brown ppts. 2. Lead chloride dissolved in sodium-chloride solut. gives colorless crystalline ppts. See Chem. News, 1883, p. 65. Palm (NICOTINE). On heating gently with a little HC1, a violet color is developed which changes to orange-red on adding NH0 3 . Palm (PICROTOXIN). An insoluble salt is formed by treatment with an ammoniacal solut. of basic lead acetate. Paneth (WEIGERT'S STAIN). In this modification i part of commercial extract of logwood is dissolved in 90 parts water and 10 parts alcohol. Then filter and add 8 drops of cone, solut. of lithium carbonate for each 100 Cc. Sections require from 1 8 to 24 hours in this stain at the normal temperature. Panum (ALBUMIN). A coagulum forms on boiling a liquid containing albumin (urine) with an equal volume of a sat. solut. of sodium sulphate or chloride. Pape (DIGITALIN). Mixture of i part amorphous digitalin with 10 parts starch gives with cone. H 2 SO 4 a paste in which the starch granules are blackish-brown, but on adding HNO 3 , deep green; if cane sugar present, the green color rapidly dis- i appears. Crystallized digitalin treated as above yields similar reactions, but the green color is more subdued. If cane sugar is added to the digitalin mixture, H 2 SO 4 causes a yellow, then orange, and finally deep-brown. The digitalin-starch mixture, treated with H 2 S0 4 , then HC1, and finally water, yields a green mass. Papasogli (CANE SUGAR). Add a few drops 5-% solut. cobalt nitrate and an excess of 50-% solut. NaOH to a solut. con- taining saccharose a permanent violet color develops. Glu- cose affords a blue color changing soon to dirty-green. Test may be applied in solutions containing glucose, caramel, or alcohol, or even in mixtures containing 10 times as much glu- cose as saccharose. Wines should first be decolorized by animal charcoal or basic lead acetate. Lactose treated as above gives an evanescent blue color. Honey gives a similar reaction, the blue becoming dirty-green. Solutions contain- TESTS AND REAGENTS. 227 ing acacia or dextrin should first be freed from these by lead acetate or barium hydrate. See Reich's test. Papasogli (COBALT). A blood-red color develops on adding a solut. of potassium cyanide till the ppt. formed is re-dissolved, then adding a few drops of yellow ammonium sulphydrate. Papasogli (NICKEL). On dissolving nickel in a solut. of potas- sium cyanide and immersing a strip of zinc, the solut. turns red, and the zinc is covered with a black deposit. Papasogli-Poli (CITRIC, SUCCINIC, AND MALIC ACIDS). On pptng. with calcium chloride, decomposing with dilute H 2 SO 4 , and boiling with potassium bichromate, a yellow color indi- cates succinic acid; green, without odor, citric acid; green, with fruity odor, malic acid. Papasogli-Poli (MALIC ACID). An odor of over-ripe fruit is given off when malic acid is heated with potassium bichro- mate and sulphuric acid. Parietti (EXTRANEOUS ORGANISMS AMONG TYPHOID-FEVER BACILLI). To prevent typhoid-fever bacilli being crowded out by extraneous organisms, add to the tubes of broth to be employed about 5 drops of a mixture of sterilized water, 100 parts; HC1, 4 parts; and carbolic acid, 5 parts. Parker (METHYLENE BLUE). This stain is fixed in sections or pieces of tissue, in the form of a finely grained purplish ppt., by cold, cone, aqueous mercuric-chloride solut. Next dehy- drate the preparations in a solut. of i Gm. mercuric chloride in 5 Cc. of methylal, then treat with a mixture of 2 parts xylene, i part of methylal, and i part of the dehydrating mixture. Subsequently leave in pure xylene for 4 or 5 days to remove all trace of mercuric chloride, and finally mount sections in balsam, or imbed tissue in paraffin prior to cutting sections. Fix sections to slide with Schaellibaum's collodion. Parker (TURPENTINE CEMENT). Dissolve true Venice turpen- tine in sufficient alcohol to enable it to pass through a filter, and after filtering the mixture, evaporate to about three- fourths its original bulk, or until a little becomes hard and breaks with a vitreous fracture when dropped into cold water. This cement is useful for closing glycerin mounts with square covers. After clearing off superfluous glycerin apply the ce- ment with a piece of copper wire bent at right angles. This 228 7 ES TS AND REAGENTS. can readily be heated in a spirit-lamp flame, and after plung- ing into the cement is brought down flat on the slide, near the edge of the cover. The cement distributes itself and hardens immediately, so that the slide can be cleaned as soon as the four sides are finished. See Csokor. Parker- Floyd (FORMALDEHYDE FOR HARDENING). A mixture of 2 volumes formaldehyde with 98 volumes water is said to harden a sheep's brain in 7 to 10 days. To obviate the ten- dency to increase the volume of the mass, mix 6 volumes of 95-% alcohol with 4 volumes of above mixture. Brains may be kept for months in the mixture. Partheil (MARGARINE). A solut. of dimethylamdioazobenzene in oil is added to the substance: on contact with a mineral acid, the mixture develops a red color if margarine present. (Reagent is not to be mistaken for Butter Yellow, the sodium salt of dimethylamidoazobenzenesulphonate.) Partsch (COCHINEAL ALUM-CARMINE). Boil cochineal for some time with a 5-% alum solution filter, and add a little salicylic acid to preserve from mold. Pasteur (CINCHONA ALKALOIDS). These bases are distinguished by their action on polarized light. See Pharm. Journ., 1857- 5 8 > P- 463- Pasteur (CULTURE MEDIUM), i. Rock candy, 10 Gm.; yeast ash, 0.075 Gm, ; water, 100 Gm. 2. Rock candy, 10 Gm. ; ammonium carbonate, iGm. ; yeast ash, i Gm. ; water, 100 Gm. Pasteur (GLUCOSE). Dissolve separately, 130 Gm. NaOH, 105 Gm. tartaric acid, 80 Gm. KOH, and 40 Gm. cryst. CuSO 4> then mix, and make up to i liter with water. Pasteur- Wurtz (FUCHSINE IN WINE). Add baryta water till the wine is faintly alkaline, then filter, acidify with acetic acid, and shake out the fuchsine with fusel oil. Pa ton (GLOBULIN IN URINE). Make urine alkaline, and overlay on sat. solut. magnesium sulphate if globulin present a white zone forms. Patrouillard (ARSENIC IN ALKALINE SALTS). Boil the sus- pected salt with 4 per cent, of oxalic acid, and identify the arsenous acid by some recognized test. Paul (BILIARY PIGMENTS). Normal urine (or urine containing sugar or albumin) colored with methyl violet, remains un- TESTS AND REAGENTS. 229 changed ; if, however, biliary pigments are present, the violet color changes to a blood-red. Paul (CiNCHONioiNE IN QUININE SULPHATE). Dissolve 5 Gm. of sample in 150 Cc. boiling water, cool, and filter; press out as dry as possible, redissolve crystals, and again crystallize. Filter, mix the filtrates, and add just enough ether to give a visible layer after shaking, then add a slight excess NH 3 , and let stand over night in a well-corked flask. Collect crystal- line cinchonidine on a tared filter, dry and weigh. Paul-Cownley (CEPH^LINE). Dissolve the ipecac alkaloids in dilute HC1; add NaOH, and shake with ether. Separate ethereal layer containing the emetine alkaloid, then acidify the soda solution and shake with ether and NH 3 . The cephaeline crystallizes out from the ether in a few hours in a mass of white light crystals. .Paul-Cownley (CEPH^LINE AND EMETINE). To determine these bases mix 50 Gm. powdered root with 10 Gm. lime, moisten with water, and extract by percolation with amylic alcohol. The alkaloids are extracted from this percolate by shaking out with dil. H 2 SO 4 . Mix acid solut. with excess of NH 3 and shake with ether. The separated ethereal solution is evaporated, and the residue titrated, with semi-normal HC1, the number of Cc. required being noted. The solut. of hydro- chlorates is then mixed with excess of NaOH, washed out with ether, the separated ether again treated with acid and with NaOH, and the process repeated until no ppt. forms on adding NH 4 C1 to the alkaline liquor. The ether solut. of emetine is then evaporated and the residue titrated with semi-normal acid, the alkaloid being expressed as emetine. From the alkaline liquors cephaeline is pptd. by adding NH 4 C1 and shak- ing out with ether, the residue of the ethereal solut. being titrated as before. The sum of the two titrations should approximate to that of the two alkaloids determined to- gether. Paul-Cownley (CUPREINE IN CINCHONA ALKALOIDS). Dissolve mixed alkaloids in weak acids, and agitate with ether and NaOH; separate the ether, then acidify the soda liquor, and shake with ether and NH 3 . Cupreine if present will separate in the form of heavy crystals in about 12 to 24 hours. 2 3 TESTS AND REAGENTS. Pavy (ALBUMIN). Citric acid and potassium (or sodium) ferro- cyanide, each in tablet form. Acidulate urine with the former, and add the latter the usual whitish-yellow ppt. indicates, presence of urine. See also Oliver's papers. Pavy (GLUCOSE). Dissolve 4.158 Gm. cryst. copper sulphate, 20.4 Gm. potassium-sodium tartrate, and 20.4 Gm. KOH in water, add 300 Cc. NH 3 (sp. gr. 0.88), and dilute with water to< i liter. Each 10 Cc. of this solut. represents 0.005 Gm. glu- cose. The solut. becomes colorless when all the cupric salt has been reduced to the cuprous condition. See Fehling's solu- tion. Pavy's cupric test pellets consist of copper sulphate, potassium-sodium tartrate, and KOH in the proper propor- tions. v Payer (HYDROCYANIC ACID). Reagent is a very dilute alco- holic solut. of guaiac resin, containing a trace of copper sul- phate. Upon bringing this mixture, in a porcelain capsule,, into contact with a glass rod moistened with hydrocyanic acid, blue streaks are formed in the liquid ; upon stirring, the whole solution turns blue. See also Schoenbein-Pagenstecher's test. Pechmann-Ihl (L/EVULOSE). See Ihl-Pechmann. Pegna (NITROBENZENE IN ALMOND OIL). Mix the oil with alcohol, add some KOH and a few drops of Fe 2 Cl 6 solut., then distil after standing for a few hours. If nitrobenzene present a dark color will develop on pouring distillate on KOH and heating; on adding chlorinated-lime solut. the color changes; to violet. Peligot (GLUCOSE). Test depends upon solubility of lime in the presence of glucose. The latter is destroyed on boiling, and on making two assays of lime, one with the cold solut. of glu- cose, the other with the same solution after boiling, the differ- ence between the two assays will represent glucose. Pellagri (BRUCINE). On dissolving brucine in cone. HC1 and heating with the addition of H 2 SO 4 , a blue color develops on neutralizing solut. with NaHCO 3 . Pellagri (INDICATOR). Prepare a solution of phyllocyanin and add sufficient of any acid to turn it purple. Alkalies change the color to green, then yellow, and finally almost black. Pellagri (MORPHINE). Dissolve the base, or the residue left on evaporating a solut. containing it, in cone. HC1, add a few TESTS AND REAGENTS. 231 drops of strong H 2 SO 4 , and heat on a water-bath a distinct purple color should be apparent. Next add more HC1, neu- tralize solut. with NaHCO 3 , and add an alcoholic solut. of io- dine the liquid acquires a deep chrome-green color. Pellet (GLUCOSE). 6.8.7 Gin. CuSO 4 , 200 Gin. of NaCl, 100 Gm. of anhydrous Na 2 CO 3 , and 6.87 Gm. of NH 4 C1 are dissolved in hot water and diluted with water to i liter. 10 Cc. of this solut. are reduced by 0.05 Gm. glucose. See Fehling's solu- tion. Pelletier (QUININE). Chlorine gas passed into water contain- ing quinine in suspension dissolves it, and the color of the solu- tion changes from light-red to violet, then to dark-red. Peloggio (IODINE). A blue color develops on passing a galvanic current through a liquid containing iodine in combination in the presence of starch paste and a little HC1. Pelouze (GLUCOSE). See Moore's test. Peltier (SILK AND WOOL FIBER). Silk is dissolved by a mix- ture of equal parts cone. HNO 3 and H 2 SO 4 , while wool is col- ored yellow. Penot (OILS). Chromic acid gives distinctive color reactions with oils. Penzoldt (ACETONE). Dissolve a few crystals of ortho-nitro- benzaldehyde in water, add to distillate from urine, then render alkaline with NaOH if acetone present, the mixture becomes yellow, then green, and after several minutes indigo precipitates. Penzoldt (BILIARY PIGMENTS). Filter a large quantity urine through a double filter; dry the latter and pour on it a few Cc. acetic acid a green color develops, particularly on warming. Penzoldt (NAPHTALIN). Let i Cc. cone. H 2 SO 4 trickle into a urine containing a trace of naphtalin the supernatant urine will be colored dark-green immediately. The acid also ac- quires the same color after a time. Penzoldt (SUGAR). Render urine strongly alkaline and treat with a i : 60 solut. of diazobenzenesulphonic acid. (Ehrlich's reagent.) At the same time a control test is made using nor- mal urine. The latter is colored yellowish-red by the reagent, whereas diabetic urine soon becomes dark-red and opaque. 2 3 2 TESTS AND REAGENTS. Penzoldt (THALLIN). Shake liquid with chloroform, and add a drop ferric-ch oride solut. to chloroformic extract a dark- green color develop if thallin present. Penzoldt-Fischer (ALDEHYDES). A red color, changing to vio- let, is produced by aldehydes on adding an alkaline aqueous solut. of diazobenzenesulphon^c acid (i : 60) in the presence of sodium amalgam. Penzoldt-Fischer (PHENOL). Diazobenzenesulphonic acid (Ehr- lich's reagent) gives a deep-red color with an alkaline phenol solut. Perenyi (FIXING FLUIDS), i. 4 parts io-% NH0 3 , 3 parts alcohol, and 3 parts 0.5-%, chromic acid solut. Immerse objects for 4 to 5 hours, then pass through 70-% alcohol (24 hours), strong alcohol (some days), absolute alcohol, (4 to 5 days), then cut sections. 2. 3 parts of 20-% NHO 3 , 3 parts of i-% chromic acid, and 4 parts absolute alcohol. This is a special mixture, used for embryos of Lacerta. Fix for 20 min- utes, wash out for an hour with 70-% alcohol, and then with strong alcohol, Stain with Delafield's hAnatoxylin, and treat for 3 to 5 minutes with i-% chromic acid. Perenyi (HARDENING SOLUTION). Mix 4 volumes of io-% HNO 3 , 3 volumes alcohol, and 3 volumes of 0.5-% solut. chromic acid. Perrins (BERBERINE). Brilliant green spangles form on adding a dilute solut. of iodine with KI to an alcoholic solut. of ber- berine. Perrot (ESSENTIAL OILS). A solut. of dimethyl- aniline violet in glacial acetic acid and dilute alcohol gives characteristic colors with many ethers, aldehydes, phenols, etc., but does not react with fatty oils or hydrocarbons. It may, therefore, be employed to detect many adulterations in essential oils. Persoz (DIFFERENTIATING TEXTILE FIBERS). Dissolve 10 Gm. zinc chloride with 2 Gm. zinc oxide in 10 Gm. water. Upon digesting any fabric in this basic zinc-chloride solut. at 30 to 40 C. any silk contained is dissolved. Pesci (ALKALOIDS). Solut. of copper sulphate and sodium thiosulphate acidulated with H 3 SO 4 . Petermann (CORN-COCKLE SEEDS IN FLOUR). Test based on isolation of the saponin in corn-cockle seeds. Heat 500 Gm. TESTS AND REAGENTS. 233 ilour with i liter 85-% alcohol, filter while hot, concentrate filtrate, and ppt. saponin by adding absolute alcohol and a little ether. Collect saponin after 12 to 24 hours, dry at 100 C., dissolve in a little water, and again ppt. with alcoholic ether. Saponin characterized by acid taste, frothing of aque- ous solut., and reduction of Fehling's solut. (especially after hydroly zing with HC1). Petri (PROTEIDS). Proteids or peptone solut. give with diazo- benzenesulphonic acid a light-yellow color changed by alkali to orange-yellow and brown, and on shaking give a red froth. Petri (KAIRIN IN URINE). Add acetic acid and solut. calcium chloride if kairin present, a fuchsine-red color develops. Pettenkofer (BILIARY ACIDS). On adding to a small quantity of a solut. of biliary acid (e. g., urine) two-thirds its bulk of cone. H 2 SO 4 , drop by drop (so as not to heat above 62 C.), and 2 to 5 drops of a i : 5 solut. of cane sugar, an intense violet or purple-red color develops. Strassburg modifies test by dis- solving cane sugar in the urine, saturating filter-paper with the solut. and, after drying, bringing the paper in contact with a drop of H 2 SO 4 . The color is then seen on holding the paper to the light. Drechsel uses phosphoric acid instead of sulphuric, and Udransky replaces the cane sugar and H 2 SO 4 by furfurol- sulphuric acid. See also Neubauer's test. By reversing the process, Pettenkofer's reaction can also be employed in test- ing for sugar and for presence of glucosides. See Brunner's test for digit alin. Pettenkofer (CARBONIC ACID). Dissolve i part of rosolic acid or corallin in 500 parts 8o-% alcohol and add baryta water until a reddish color is obtained. On adding 0.5 Cc. of this solution to 50 Cc. water containing bicarbonates, the red color will disappear if free CO 2 present. Pettenkofer (SUGAR). By reversing Pettenkofer's process for detecting biliary acids, as in Brunner's test, the reaction serves as a test for sugar from glucosides. H 2 SO 4 is added to an aqueous solution of the bile till the precipitate first formed is redissolved, and on adding the liquid containing sugar, a vio- let color develops. Petti (PHYSOSTIGMINE). On adding dil. HC1 to saturation, fol- lowed by excess of NH 3 , and then heating, the color-changes 234 TESTS AND REAGENTS.' in the case of physostigmine will be as follows: Pale-red, red,, yellowish-red, green, and blue. Pewsner-Nastinkow (STAINING TUBERCLE BACILLI). Shake a i: 2,000 solut. HgCl 2 with a few drops aniline, and filter. To 10 Cc. filtrate add i Cc. io-% solut. gentian- violet, methyl- violet, or fuchsine, in absolute alcohol. Immerse specimen in this solut. for 5 minutes, rinse in water, decolorize with dil. HC1, and again wash with water. Preparation may now be tinged with complementary colors (solut. malachite green or cosine, 0.06 Gm. in 60 Cc. i: 2,000 solut. HgCl 2 ). Prepara- tion should not remain longer than i or 2 seconds in latter solut. To detect tubercle bacilli in the tissue, dehydrate latter by 2 days' immersion in absolute alcohol, then imbed in mix- ture of 5 parts paraffin and i part chloroform for 20 to 60 minutes, then in pure melted paraffin for 10 to 20 minutes (on water-bath). When cold, make sections, from which dis- solve out paraffin with xylene, wash with alcohol, and im- merse in water. Then dry sections on glass, treat with chlo- roform, and stain as above. Pfeiffer (SERUM REACTION FOR CHOLERA). Trace of blood serum of a cholera-immune guinea-pig destroys vitality of true cholera bacilli contained in serum of normal guinea-pig and a little bouillon. Vibrios similar to those of cholera are not killed by the serum; other tests, such as that for typhoid bacilli may be carried out in similar manner. Gruber states that the reaction may be conducted in a test-tube. See WidaVs test. Pfitzner (DAMMAR SOLUTION). Dissolve dammar in a mixture of benzene and turpentine. Pfitzner (SAFRANINE STAIN). Dissolve i part safranine in 100* parts absolute alcohol, and after a few days add 200 parts water. Pfuhl-Petri (TUBERCLE STAIN). Stain in warmed solut. of 10 Cc. sat. alcoholic solut. fuchsine and 100 Cc. water, for i or 2 minutes. Decolorize in acetic acid for i or 2 minutes, rinse in water, and double-stain in alcoholic aqueous solut. mala- chite green for to i minute; then rinse in water, dry, and mount in balsam. TESTS AND REAGENTS. 235 Phipson (BENZOIC, HIPPURIC, AND SALICYLIC ACIBS). On mix- ing 3 equivalents of acid with i equivalent of glucose and a large excess of H 2 SOf, a moderate heat causes development of a brown color changing to black. See Chemical News t xxviii, 13. Phipson (FRANGULIN). H 2 SO 4 causes an emerald-green color changing to purple and then dark-red. Pianese (METHYLENE-BLUE-EOSINE STAIN). The same as Cken- zinsky's solut., with addition of a considerable proportion of lithium carbonate. , Picard (AMMONIACUM). Modified Plugge's reagent for ammo- niacum, with substitution of sodium hypobromite for sodium hypochlorite. Piccini (NITRIC IN PRESENCE OF NITROUS ACID). Add urea to the liquid containing nitrates and nitrites, which then mix with a solut. of urea in dil. H 2 SO 4 . When evolution of nitro- gen* from decomposed nitrites ceases, a blue color develops on adding KI, starch paste, and a fragment of zinc. Pichard (NITRITES). Add a particle brucine and i drop HC1 to solut. in about 5 minutes a vermilion-red to light-yellow color develops if a nitrite present; i part nitrous nitrogen in 640,000 water thus detected. Nitrates treated as above give no reaction. Said to be more sensitive than Griess, Troms- dorff and Piccini tests. Pick (PRESERVATIVE SOLUTION FOR ANATOMICAL SPECIMENS). 50 Gm. formaldehyde, 50 Gm. artificial Carlsbad salts, 1,000 Cc. water. Pick (STAIN FOR GONOCOCCI). Ziehl's carbol-fuchsine, 15 drops; cone, alcoholic solut. methyl blue, 8 drops; dist. water, 20 Cc. Stain cold for 10 seconds, wash, dry, and mount. Gonococci are stained deep-blue; other bacteria light-blue, cell nuclei very light-blue, and protoplasm pink. Pictet (EXAMINATION LIQUID). A 5- to io-% solut. of man- ganese chloride is used in place of normal salt solution for marine animals. For terrestrial animals use a i- to 3-% solut. only. Piffard (SUGAR IN URINE). A paste is prepared by mixing in the mortar copper sulphate, i ; sodium-potassium tartrate, 5; NaOH, 2. See Fehling 's solution. 236 TESTS AND REAGENTS. Pilhastry (FORMALDEHYDE). Dissolve i Gm. phenylhydrazine hydrochlorate and 1.5 Gm. sodium acetate in 100 Gm. water. On heating 3 Cc. of the suspected solut. for i minute with 5 drops H 2 SO 4 and 5 drops of the reagent, a characteristic green color develops (visible in solut. of formaldehyde i : 250,000). Pinerna (ORGANIC ACIDS). A solut. of beta-naphtol, 0.02 Gm. in cone. H 2 SO 4 , 1.83, i Cc. If 0.05 Gm. of organic acid is carefully heated with 10 to 15 drops of reagent, distinctive color reactions are obtained; tartaric acid gives a blue then green color, on dilution, a reddish-yellow tint; citric acid reacts with a blue color, on dilution colorless, to light-yellow; malic acid greenish-yellow, then light-yellow, and orange on dilution. Piotrowski (PROTEIDS). This is the biuret reaction. See also Rose's, Bruecke's, Posner's, and Ritthausen's tests. Pirette (BUTTER). Modified Reichert-Meissl method. Add 10 Cc. H 2 SO 4 to 5 Gm. butter stirring constantly. When mixture clear and transparent, dilute with 150 Cc. water, and add cone, solut. potassium permanganate until red color retained for several seconds. Odor of SO 3 will then have disappeared, and the acid completely oxidized. Then distil off 1 10 Cc. and treat as usual. Piria (TYROSIN). Heat sediment from suspected urine with a little cone. H 2 SO 4 for 5 to 10 minutes, dilute with water, warm, neutralize with calcium or barium carbonate, and treat the filtrate with ferric-chloride solut. The solut. is colored violet if tyrosin present. An excess of ferric chloride destroys the color. Piria- Staedeler (TYROSIN). In this modification of Piria } s test, the urinary sediment is warmed with the acid, then neutralized with barium carbonate, boiled, filtered, and added drop by drop to a dil. solut. Fe 2 Cl 6 . Piso Bonne - Moleschott (SOLUTION). See Moleschott - Piso Borme. Planta (ALKALOIDS) . Potassio-mercuric iodide gives white ppts. See Mayer's test. Plaut (ACTINOMYCOSIS). Place sections of tissue affected with actinomycosis for 10 minutes in Gibbes' magenta solut., or Ziehl-Neelsen carbolic-fuchsine solut. at 45 C.; next rinse TESTS AND REAGENTS. 237- in water, and place in sat. aqueous solut. of picric acid, mixedt with an equal volume absolute alcohol, for 5 to 10 minutes, wash with water, pass through 50-% alcohol into absolute alcohol, clear in cedar oil, and mount in balsam. In Squire's modification, the sections are placed for 10 minutes in car- bolic- fuchsine, and decolorized for 24 hours in fiuorescine alcohol (yellow fluorescine, i Gm. rubbed in a mortar with 50. Cc. of absolute alcohol, and allowed to settle). Stain the nuclei with Ehrlich's hematoxylin and counter-stain faintly with benzopurpurine solution (0.25 Gm. in 20 Cc. alcohol, and 80 Cc. distilled water). Plessy-Matthieu (GLUCOSE; SUGAR; PYROGALLOL). See Mat-. thieu-Plessy. Plugge (ALBUMIN). Reagent used in Plugge' s test for phenol yields a red color with albumin, similar to that produced by Millon's reagent for albumins and phenols. Plugge (AMMONIAC). Dissolve 30 Gm. NaOH in water, keep, solut. cool while adding 20 Gm. bromine, and then dilute to. i liter. A drop of this solution, added to an aqueous or alco^ holic solut. of ammoniac prepared with the addition of NaOH,, causes a beautiful violet color which rapidly disappears. Plugge (NITROUS ACID). A red color develops on heating to, boiling 5 Cc. of a solut. of mercurous nitrate with 5 Cc. car- bolic acid (i: 100), and 15 Cc. water, then adding 120 to 150, Cc. of a liquid containing nitrous acid. Plugge (PHENOL). Boil a dil. solut. with mercurous nitrate- solut. containing a slight trace nitrous acid. Phenol causes, appearance of an intense red color, while metallic mercury separates out and an odor of salicylol develops. See Frese-- nius' phenol reaction. Podwyssotzki (EMETINE). A drop sat. solut. of sodium phos-. pho-molybdate in cone. H 2 SO 4 yields with emetine a brown color, which changes to blue on adding a drop HC1. Podwyssotzki (FIXING MIXTURE). Mix 15 Cc. i-% chromic acid dissolved in 0.5-% corrosive sublimate solut., 4 Cc. 2-% osmic-acid solut., and 6 to 8 drops glacial acetic acid, Podwyssotzki (SAFRANINE STAIN). After staining, different tiate for two minutes or less in a strongly alcoholic picric-acid, solut. followed by pure alcohol. TESTS AND REAGENTS. Poehl (PRODUCTS OF ASIATIC CHOLERA BACILLI). Add 10 drops cone. H 2 SO 4 to 7 Cc. pure culture of comma-bacillus a rose color deepening to purple develops. (Indol reaction; other bacteria also elaborate indol, but comma-bacillus and one or two others elaborate nitrous acid also, which is neces- sary for the reaction.) Poelzam (IMBEDDING MASS). Cut good white soap in thin slices, dry in the sun, powder, and mix into a paste with spirit. Next mix paste with 90-% alcohol and glycerin in such pro- portions that the whole shall contain for every 10 parts by weight of soap, 22 parts of glycerin and 35 parts of alcohol. Let the whole simmer until a transparent, syrupy fluid is obtained. This mass may be removed from sections by means of water or very dilute alcohol. Pohl (PICRIC ACID). A woollen thread is colored yellow on soaking in a picric-acid solut. and rinsing in water. Pohl (PRECIPITANT FOR GLOBULIN). Make alkaline with NH 3 , and filter after several hours, then add to nitrate equal vol- ume sat. solut. ammonium sulphate a ppt. forms if globulin present. Poll (SERIAL SECTIONS). Arrange sections on a layer of melted Kaiser's gelatin, add glycerin, and cover. Poli-Papasogli (CITRIC, SUCCINIC, AND MALIC ACIDS). See Papasogli-Poli . Pollacci (ALBUMIN IN URINE). Reagent is a solut. of tartaric acid, i; HgCl 2 , 5; NaCl, 10; water, 100; formaldehyde (40-%), 5. To test sample put 2 Cc. solut. in test-tube and overlay with 3 or 4 Cc. urine a ring appears immediately at line of separation of the liquids if pathological albumin present. If the ring appears slowly ( i o to 15 minutes) urine is pathologi- cally right. Test sensitive to i : 370,000, according to author. Pollacci (GLUCOSE). Shake liquid with 4 Cc. water, i drop aqueous solut. ferric chloride, and 6 drops solut. of soda; boil, add 2 drops H 2 SO 4 , cool, and add a fresh solut. potassium ferricyanide. Glucose produces a blue color. Pollacci (IODATES IN IODIDES). Heat alkaline liquid, and add a piece phosphorus, which will soon be surrounded by a dark- yellow zone. Amorphous phosphorus promptly reduces iodates to iodides. TESTS AND REAGENTS. 239 Tollacci (PHENOL), i. An aqueous solut. containing phenol overlaid on H 2 SO 4 causes a red color at the line of contact. 2. A brown color is produced on adding a drop of liquid to H 2 SO 4 and potassium bichromate. Tollacci (SULPHURIC ACID IN VINEGAR). Immerse strips of filter-paper in a beaker containing the vinegar, so that one end of each touches the bottom and the other projects about i Cm. above the top. After 24 to 36 hours, cut off projecting portions of strips, moisten with ether, and when that has evaporated take up the soluble matter with water and ex- amine for H 2 SO 4 . Pollak (MELANIN). See Von Jaksch's test. Pollet (REAGENT). Kopp's reagent. Porret (FERRIC SALTS). A blood-red color develops on adding solut. potassium sulphocyanide. Posner (PEPTONE AND ALBUMINS IN URINE). The urine, made alkaline, is poured into a test-tube and carefully overlaid with very dilute, almost colorless copper-sulphate solut. peptone causes the formation of a violet zone in the cold; albumin gives the same reaction upon warming. See also Brucke's and Rose's biuret reactions. Potain-Drouin (CARBONIC OXIDE IN AIR). Pass current of air in very fine bubbles through 10 Cc. of io-% solut. palla- dium chloride acidulated with 2 drops HC1 if carbonic oxide present in air, a black film of palladium is deposited on sides of flask and tube. Pouchet (BLEACHING METHOD). Macerate sections in glycerin to which a little hydrogen dioxide has been added (5 or 6 drops to a watch- glassful). Poutet (FIXED OILS). Mix 10 Gm. oil, 5 Gm. HNO 3 (of 40 to 42 Be.), and i Gm. mercury; shake 3 minutes till mer- cury dissolved, allow to stand 20 minutes, and again shake i minute. Various fats show differences in color and in the time they take to solidify. Olive and peanut oils harden most rapidly. In one modification of this ela'idin reaction the proportions used are 50 Cc. of oil, 12 Gm. of mercury, and 15 Gm. of nitric acid (sp. gr. 1.35). Olive and almond oils only are solidified by this. Another modification, recommended more particularly for determining purity of olive oil, is to mix 24 TESTS AND REAGENTS, the oil with one-twelfth its weight of a solut. of 6 Gin. mercury in 7.5 Gm. HNO 3 (sp. gr. 1.35). Shake every 10 minutes for 2 hours, then put in a cold cellar and observe consistence after 24 hours. Power (ELATERIN). A deep-red color develops on adding H 2 SO 4 , while addition of potassium bichromate causes a brown to light-green color. Power (EMETINE). A bright-orange to lemon-yellow color de- velops on adding solut. chlorinated lime and i drop acetic acid. Power (GLUCOSE). A colorless solut. is obtained on heating the liquid to boiling with i drop copper-sulphate solut. (1:14) and a slight excess ammonia. Pradines (FUCHSINE IN WINE). Distil off alcohol and to 10 Cc. of residue add 4 Cc. ammonia; shake well with 5 Cc. ether and separate. A drop of the ethereal layer placed on white paper or muslin gives a rose-red stain if fuchsine present. If desired, the residue left after distillation may be shaken with a sat. solut. of ammonia in ether. Pratesi (GLUCOSE IN URINE). Potassium hydrate, 2.5 Gm.; solut. potassium silicate (cone.), 60 Gm.; potassium bichro- mate, 2 Gm. Allow 5 drops of reagent to dry on strip of tin; on heating, tin becomes yellow. Add urine if glucose pres- ent, a green color develops on heating. Prescott (CARBOLIC ACID). A yellow color develops on adding a few drops HNO 3 , then a slight excess of KOH, and diluting with water. Prescott (SuLPHOCARBOLATEs). A yellow color develops on boiling in water with HNO 3 and neutralizing with KOH. Preusse-Baumann (HYDROQUINONE). See Baumann-Preusse. Preyer (CARBON MONOXIDE IN BLOOD). 3 to 4 drops of sus- pected blood are warmed for 5 minutes at 30 C. with 10 Cc. water and 5 Cc. potassium-cyanide solut. (1:2). The spectrum of normal blood, so treated, lacks the absorption line of oxy- hemoglobin, and in its place shows a broad absorption band; the spectrum of carbon-monoxide blood remains unchanged. Price (IODINE). A blue color develops on mixing with starch and adding HC1 and solut. potassium nitrite. Pritchard (HARDENING FLUID). Dissolve i part chromic acid in 20 parts water and add 120 parts alcohol. TESTS AND REAGENTS. 241 Pritchard (REDUCING SOLUTION). An aqueous solut. contain- ing i % each of amyl alcohol and formic acid. Used for reduc- ing gold chloride after impregnating animal tissues with that salt. Prochazka-Endemann (COPPER). See Endemann-Prochazka. Procter (CANNABIS EXTRACT). HNO 3 converts the extract into an orange-red resin. Proctor (TANNIC AND GALLIC ACIDS). A green color develops on adding a faintly alkaline solut. of sodium or potassium arsenate, and a purplish-red on adding acids. Proescher (BILIRUBIN IN URINE). Saturate 10 Cc. urine with (NH 4 ) 2 SO 4 , collect ppt. and exhaust it with 96-% alcohol. Acidulate alcoholic extract and treat it with a diazo solut. prepared by mixing a solut. of (a) sulphanilic acid (Erhlich) 5 Gm., or paramidoacetophenone (Brunner) 0.5 Gm., HC1 50 Gm., and water 1,000 Gm., with a solut. of (c) NaNO 2 5 Gm., in water 1,000 Gm. If bilirubin present, solut. acquires a blue color. Bilirubin may thus also be detected in serum. Proksch (RHUBARB IN URINE), i. Add to urine HC1, then xylene, and shake. Overlay xylene solut. on KOH lye if rhubarb present a pink color develops at contact-point of liquids. 2. The same test conducted with chloroform instead of xylene gives a violet zone. 3. If SO 3 be added to urine, mixture shaken with chloroform, and chloroformic solut. overlaid on potassa lye, pink zone forms. 4. Shake urine with sulphanilic acid and xylene lower aqueous layer will be wine-red, while upper xylene layer will be faint pink if rhubarb present. Senna may give similar reactions, though in less degree. Prollius (SOLUTION). Mixture of 88 parts ether, 8 parts of abso- lute alcohol, and 4 parts of spirit of ammonia; for extracting cinchona bark for the determination of alkaloids. Purdy (GLUCOSE). 4.15 Gm. copper sulphate, 10 Gm. mannite, 20.4 Gm. KOH, 300 Cc. ammonia (sp. gr. 0.88), 50 Gm. gly- cerin, and enough water to make i liter. 25 Cc. will be reduced by o.o 1 5 Gm. grape sugar. See also Fehling's solution. Purgotti (COPPER). A blue color develops on mixing the solut. with an alkaline chloride and overlaying with tincture of guaiac. 242 TESTS AND REAGENTS. Pusch (BENZENE AND BENZIN). Iodine gives a violet solut. with benzene, and raspberry-red with benzin. Pusch (CITRIC AND TARTARIC ACIDS). On heating i Gm. powdered substance on a water-bath, with 10 Gm. H 2 SO 4 , citric acid turns lemon-yellow; tartaric acid becomes brown or black. Puscher (ALCOHOL IN ETHEREAL OILS). A few drops ethereal oil are introduced into a test-tube, and the upper portion of tube dusted with powdered fuchsine, or the latter is introduced by means of a cotton swab. Upon boiling, the alcohol, evap- orating first, dissolves the fuchsine and forms a red solution. Puscher (ARSENIC IN GREEN COLORS). Ammonia gives a blue color, and when evaporated the solut. leaves a dirty yellowish- green stain. A pale-blue stain indicates absence of arsenic. Puscher (FUCHSINE IN FRUIT JUICES). A woollen or silk thread soaked in the juice and then rinsed in water is colored red. Quirini (GLUCOSE IN URINE). Add 10 drops urine to 5 Cc. 0.5-% solut. of orthonitrophenylpropiolic acid in soda lye and boil \ minute if sugar present (even 0.1%) urine ac- quires a dark-blue color (formation of indigo). Normal urine so treated is at most colored green. See also Hoppe-Seyler's test. Raabe (ALBUMIN IN URINE). Trichloracetic acid (sat. solut.) overlaid on the cold urine coagulates albumin, but not mucin or peptones. When crystallized trichloracetic acid is added to urine it sinks to the bottom of the liquid and is dissolved, forming a turbid zone. Rabl (ALUM COCHINEAL). Practically identical with Czokor's cochineal alum-carmine. Rabl (CHLORO-FORMIC ACID). Add 4 or 5 drops of cone, formic acid to 200 Cc. of 0.33-% chromic-acid solut. Squire gives the following formula: 7 Cc. io-% chromic-acid solut., 200 Cc. water, and 5 drops formic acid (sp. gr. 1.2). The mixture must be freshly prepared at the moment of using and small pieces of tissue should be fixed in it for 12 to 24 hours, then washed with water, hardened in alcohol of gradually increas- ing strength, and stained with Delafield's hematoxylin or safranine. This is one of the best reagents for the study of karyokinesis. TESTS AND REAGENTS. 243 Rabl (PiCRO-SuBLiMATE). Mix i volume each of sat. solut. mercuric chloride and picric acid, and add 2 volumes dist. water. Embryos may be left to harden in this for 2 hours, prior to removal into weak alcohol. Rabl (PLATING-SUBLIMATE MIXTURE). Mix equal volumes of i-% platinic chloride solut., sat. mercuric-chloride solut., and distilled water. This is used for hardening embryos of verte- brates and for other objects. Rabl (PLATINUM FIXING SOLUTION). Leave objects 24 hours in aqueous solut. platinic chloride (1:300), then wash with water, harden in alcohol and cut sections. Stain with Dela- field's hematoxylin or safranine. Rabl (SERIAL SECTIONS). Secure sections to slides by employ- ing a modified Schaellibaum solut. (2 parts collodion and 3 parts clove oil). Rabl (STAINING METHOD). Stain very lightly with dil. Dela- field's hematoxylin solut. for 24 hours, wash out first with water, then with alcohol acidulated with HC1, next strain for some hours in Pfitzner's safranine, and wash out with pure alcohol. Rabourdin (IODINE). If to a liquid containing iodine 2 drops HNO 3 , 15 drops of H 2 SO 4 , and a little chloroform be added, a violet color will be imparted to the chloroform. Rabuteau (BROMIC AND CHLORIC ACIDS IN URINE). Add a little indigosulphonic acid to urine, followed by H 2 SO 4 the indigo is decolorized by any chlorine or bromine produced by reduction of chloric or bromic acid. Rabuteau (HYDROCHLORIC ACID IN GASTRIC JUICE). Starch solut., 50 Cc.; potassium iodate, i Gm.; and potassium iodide, 0.5 Gm. The reagent turns blue with free HC1. Rafaele (ALBUMIN IN URINE). Use HC1 instead of acetic acid in Spiegler's test, which see. Ralfe (ACETONE IN URINE). Boil 4 Cc. KOH solut. containing 1.5 Gm. KI and overlay with 4 Cc. urine if acetone present contact zone is yellow, with specks of iodoform. Lactic acid and some other substances also give the reaction. Ralfe (PEPTONES IN URINE). Overlay Fehling's solut. with equal vol. urine if peptones present a rose-colored halo above zone of phosphates appears. 244 TESTS AND REAGENTS. Ramsay (BLEACHING SOLUTION). Solut. magnesium hypo- chlorite, also known as Crouvelle's bleaching fluid. Ramsay (CARBONYL CHLORIDE IN CHLOROFORM). Add clear- baryta water to chloroform and let stand some hours in a stop- pered vessel if carbonyl chloride present a white film (ba- rium carbonate) forms at junction of the liquids. (Carbonyl chloride may be removed from chloroform by shaking latter with slaked lime.) Randolph (PEPTONES IN URINE). To 5 Cc. cold, faintly alka- line urine add 2 drops sat. solut. KI and 3 or 4 drops Millon's solut. a yellow ppt. forms if peptones present. Sensitive to i: 17,000. Biliary acids also give reaction. Ransom- Duns tan (ALKALOIDS IN BELLADONNA). See Dunstan- Ransom. Ranvier (ABSOLUTE ALCOHOL). Alcohol, absolute enough for most purposes, may be obtained by treating 95-% alcohol with calcined cupric sulphate for several days, repeating operation with fresh sulphate several times until it ceases to become conspicuously blue, and no particles of water become visible when a drop of alcohol mixed with turpentine is examined under the microscope. Ranvier (AMMONIA CARMINE). Dissolve carmine in water with a slight excess NH 3 , and expose solution to air until entirely dried up. The residue is then dissolved in distilled water and the solut. filtered. Ranvier (CARMINE-GELATIN INJECTION). Soak 5 Gm. gelatin in water until quite swollen and soft (about hour), wash, drain, and melt on a water-bath. Then add slowly a solut. prepared from carmine, 2.5 Gm. and a little water, using just enough NH 3 to afford a transparent solut. Next neutralize by cautiously adding by drops, with continuous agitation, a mixture of i part glacial acetic acid and 2 parts water. Care must be taken to avoid formation of a granular ppt. on adding the excess of acid. Finally strain through flannel. Ranvier (DECALCIFYING LIQUID). 50-% HC1 with sufficient NaCl to counteract its swelling action. Ranvier (FORMIC- ACID METHOD). Thoroughly impregnate tis- sues in a mixture of 4 parts i-% gold-chloride solut. and i part formic acid which has been boiled and allowed to cooL TESTS AND REAGENTS. 245 Then reduce the gold by action of daylight, in acidulated water, or in the dark, in 20-% formic acid. Ranvier (IODIZED SERUM). Iodine is added to the recent amniotic liquid of mammals, and the mixture agitated for several days. Or, serum is mixed with a large proportion of tincture iodine and the ppt. removed by filtration. The re- sulting strong serum is kept in stock and a little added every 2 or 3 days to the serum intended for use. Ranvier (LEMON-JUICE METHOD). Soak pieces of fresh tissue in fresh lemon juice until transparent (5-10 minutes), then rapidly wash in dist. water, treat for 10 to 60 minutes with a i-% gold-chloride solut., again wash, and expose to light in a bottle containing 50 Cc. dist. water and 2 drops acetic acid. Re- duction is complete in 24 to 48 hours. If it is not desired to retain the superficial epithelium, reduction may be more com- pletely effected in the dark by treatment with formic acid (sp. gr. 1.2) diluted with 3 volumes water. The lemon juice in this process may be replaced by an aqueous solut. citric acid (40 grains to each fl. oz.). Ranvier (ONE-THIRD ALCOHOL). This mixture (2 parts dist. water and i part 90-% alcohol) is known in France as "Al- cool au tiers"; in Germany as "Drittelalcohol" or "Ran- viersche alcohol dilutus"; in Italy as " Alcool al terzo." It is a very mild fixative, and objects should not be left in it for more than 24 hours. They may then be stained with picro- carmine, alum-carmine, or methyl-green. Ranvier (PICRO-CARMINE). Water, 1,000; picric acid, 20; car- mine, 10 ; ammonia, 50. Keep in a stoppered bottle in a warm place for 2 to 3 months, then expose in a large dish until liquid reduced to four-fifths its original volume. Then re- move the crystals that have formed, dry, and dissolve in a little warm water. If, after filtration, the carmine does not appear to be dissolved, when examined under the microscope, add more water and NH 3 , and expose as before. When car- mine properly dissolved, evaporate filtered solut. to dryness, and reduce residue to powder. For staining, dissolve i Gm. of the powder in 100 Gm. water, and add a crystal thymol to prevent mold. 246 TESTS AND REAGENTS. Ranvier (PRUSSIAN-BLUE INJECTION). Mix cone, soluts. fer- rous sulphate and potassium ferrocyanide by pouring former into the latter, taking care to have an excess of latter. Filter off liquid and wash ppt. with dist. water until it becomes soluble, then make a cone, solut. of it. Soak i part gelatin in water for half hour, wash, melt, and add gradually to 25 parts of blue solut. heated to same temperature, stirring con- tinually with a glass rod until curdy ppt. first formed disap- pears. Then filter through flannel and keep at 40 C. on a water-bath until injected. The soluble Prussian blue pre- pared as above is sometimes used without gelatin, or it may be mixed with one-fourth glycerin. Ranvier (SILVER-NITRATE INJECTION). Mix 2, 3, or 4 parts cone, solut. gelatin with i part i-% solut. silver nitrate. Ranvier-Vignal (OSMIUM MIXTURE). Fix tissues in a freshly made mixture of equal volumes i-% osmic acid and 90-% alcohol, then wash out in 80- % alcohol, next with water, and stain for 48 hours with picro-carmine or hematoxylin. This method has been applied to the histology of insects. Raspail (ALBUMINOIDS). These are colored red by sugar and cone. H 2 SO 4 . See also Schultze's furfurol reaction. Raulin (CULTURE MEDIUM). Rock candy, 0.7 Gm.; tartaric acid, 0.04 Gm.; ammonium nitrate, 0.04 Gm.; ammonium phosphate, 0.6 Gm. ; potassium carbonate, 0.6 Gm. ; mag- nesium carbonate, 0.4 Gm. ; ammonium sulphate, 0.25 Gm.; zinc sulphate, 0.07 Gm. ; ferrous sulphate, 0.07 Gm.; potas- sium silicate, 0.07 Gm. ; water, i ,500 Gm. Rauwerda (CYTISINE). A drop of nitrobenzene containing a little dinitro-thiophene gives a quite persistent violet-red color with cytisine or its salts. 0.0005 Gm. cytisine may be recog- nized. Coniine alone gives similar reaction, but color fades rapidly. Rawitz (HEMATEIN STAIN). Add i to 3 drops of strong alum- hematein solut. to 25 or 50 Cc. distilled water, and stain sec- tions of picric or sublimate material in the mixture for 24 to 48 hours. Rawitz (INVERT STAIN). Place sections fixed in Flemming's liquid or some other chromic mixture in a 20-% aqueous solut. or tannin for 24 hours. Then wash and treat for 2 or 3 hours TESTS AND REAGENTS. 247 with a i- to 2.5-% solut. of tartar emetic, kept at a tempera- ture of 37 C., or for 24 hours with the same solution at the normal temperature. Again wash and stain for 24 hours with safranine, fuchsine, methyl violet, gentian violet, or emerald green. Differentiate with alcohol or by treatment for 2 to 24 hours with 2.5-% tannin solution, then clear and mount. Raymond!- Bertoni (NITROUS ACID IN BLOOD). See Bertoni- Raymondi. Read (CARBOLIC ACID AND CREOSOTE). Strong solut. of am- monia dissolves carbolic acid, but not creosote. Reale (FREE HYDROCHLORIC ACID). In a solut. ferric chloride containing free HC1, a i-% solut. carbolic acid gives a greenish color. If free acid absent, an amethyst color appears; a large quantity of acid prevents coloration. Redenbaugh (NARCOTIZATION METHOD). Add crystals of mag- nesium sulphate to water containing marine animals until a sat. solut. is obtained; or, in the case of annelids, throw them into a sat. solut. of the salt. Redwood (ALCOHOL IN ESSENTIAL OILS). Addition of HN0 3 is followed by evolution of nitrous fumes. Ree (PRECIPITANT FOR ALBUMIN). Alcoholic tannin solu- tion. Rehm (STAINS FOR NERVE CELLS), i. Wash sections for a few minutes in aqueous solut. Congo red, then in alcohol, and afterwards treat for i o minutes (until they become blue) with alcohol acidulated with HC1 or HNO 3 . Clear with origa- num oil and mount. 2. Place sections of alcohol-hardened material in a 0.5-% aqueous solut. of hematoxylin for i or 2 days, wash in aqueous solut. lithium carbonate until no more color comes away, then dehydrate and mount. After- stain, if desired, for a few minutes with o.i-% aq. solut. Bismarck brown. Rehm (STAINS FOR Axis CYLINDERS), i. Stain sections of alcohol-hardened material for 5 minutes in i-% ammonia- carmine, wash out in 70-% alcohol acidified with i-% HNO 3 , then with pure alcohol; stain for half a minute in o.i-% methylene-blue solut., differentiate in alcohol, clear in origa- num oil, and mount in colophonium. 2. Employ a modifica- tion of Nissl's method, in which sections of alcohol-hardened 248 TESTS AND REAGENTS. material are stained for half a minute to a minute in hot o.i-% methylene-blue solut., wash in 96-% alcohol till no more color comes away, clear with origanum oil, and mount in balsam or benzene-colophonium. Reich (CANE SUGAR). Cobalt-nitrate solut. and KOH or NaOH when added to solut. of cane sugar develop a violet color. According to Dupont, glycerin, milk sugar, glucose, and invert sugar do not interfere with the reaction, but dextrin and gums should be removed by pptng. with lead acetate or baryta water. Reich (GLUCOSE), i. No violet color or ppt. is formed on add- ing KOH and boiling, then adding cobalt nitrate. 2. No color reaction is given on adding boiling solut. of potassium bichromate. Reichardt (ARSENIC IN URINE), i. To 200 Cc. urine add 2 Gm. NaOH and evaporate off liquid; then dissolve residue in a little water acidulated with HC1 and test in Marsh's ap- paratus. 2. Saturate slightly acidulated urine with H 2 S, collect ppt. in 12 to 14 hours, and wash ppt. and filter with bro- mine water to dissolve As 2 S 3 . Place washings in Marsh's apparatus, and pass evolved gas into a solut. AgNO 3 o.i to 0.2 Gm., and HNO 3 2 Gm., in water 10 Cc. Any AsH 3 formed causes a black-brown ppt. of metallic As, or latter forms at tip of immersed tube. Reichardt (!ODIC ACID). On mixing a solut. of an iodate with a solut. of morphine sulphate containing a few drops H 2 SO 4 a brown ppt. (of iodine) or a yellowish-brown color, according to quantity of iodic acid present. A little NH 3 added after reaction commences increases sensitiveness of reaction, and renders color more permanent. For details, see MERCK'S REPORT, ix, p. 517. Reichardt (NITRIC ACID). Upon treating a solut. of brucine in H 2 SO 4 with a few drops solut. containing HNO 3 , a rose-red to deep-red color develops. Or, to i drop of the water add 3 drops of brucine solut. and a few drops H 2 SO 4 color appears even in dilutions of i : 100,000. Reiche (ACACIA). Boiling with a solution of orcine in HC1 causes a red to violet color and a blue ppt., which dissolves in alcohol with a greenish-blue color. Alkalies change the latter color to violet with greenish fluorescence. TESTS AND REAGENTS. 249 Heichert-Meissl (FOREIGN FAT IN BUTTER). Weigh into a flask 5 Gm. melted butter, add 2 Cc. of 50-% NaOH solution, and 30 Cc. alcohol. The fat is then saponified under a reflux condenser by brisk boiling for 20 minutes. The spirit is then boiled off, the last traces being carefully driven off. 100 Cc. of hot water are then added, the soap dissolved, 40 Cc. of dilute H 2 SO 4 are next added, and no Cc. of liquid is slowly distilled over. 100 Cc. of this are then titrated with decinormal soda, using phenolphtalein as an indicator. Pure butter contains volatile fatty acids, which use up from 24 to 32 Cc. of deci- normal alkali for 5 Gm. taken. Reichert-Meissl (NUMBER). Indicates the number of Cc. of decinormal NaOH or KOH solut. required to neutralize the volatile fatty acids obtained by a special process from 5 Gm. of a fat. Reichert's numbers formerly in vogue gave the fig- ures for 2.5 Gm. of fat, and are therefore only half as large as the Reichert-MeissVs numbers. Reichl (GLYCERIN), i. Equal parts of glycerin and carbolic and sulphuric acids are mixed and heated to 120 C., and water added to the brownish-yellow, solid mass after cooling. NH 3 is then added drop by drop, when the mass dissolves, forming a beautiful carmine-red solut. 2. A violet-red color develops on boiling glycerin with an equal volume water, a little pyrogallic acid, and a few drops H 2 SO 4 , then adding stannic chloride. Reichl-Mikosch (ALBUMIN). If 2 to 3 drops of alcoholic benz- aldehyde solut. are added to solut. to be examined, then a larger volume of dil. H 2 SO 4 (i : i), and finally a few drops of Fe 2 Cl e , a deep-blue color develops if albumin present. Reac- tion hastened on warming. Reinke (FLEMMING'S ORANGE METHOD). In this modification of Hermann's liquid, sections are left for 24 hours in cone. K 2 SO 3 solut. Then wash with water and stain for i to 2 hours with safranine, wash well in water, and stain for 24 hours with a cone, aqueous solut. gentian violet to which a few drops of a similar solution of orange G. have been added. Differentiate rapidly with alcohol and clear with clove oil. Reinsch (ARSENIC TEST). A solut. of arsenous or arsenic acid in HC1 is reduced by metallic Cu, a gray coating of copper 250 TESTS AND REAGENTS. arsenide being deposited upon the metal. Sb and Hg behave similarly, hence their absence must be proved before the presence of As can be decided upon. Test is also known as- Hager's empirical arsenic test (kramato method). Reinsch (SULPHUROUS ACID). A brown or black stain is pro- duced on copper by H 2 SO 3 in the presence of HC1. Reissner (NUCLEO-ALBUMIN IN URINE). Filter urine, dilute, and add excess of acetic acid turbidity indicates presence of nucleo-albumin. Remak (SOLUTION FOR HARDENING MICROSCOPICAL PREPARA- TIONS). 50 Cc. 20-% aqueous CuSO 4 solut., 50 Cc. 25-% alcohol, and 35 drops of purified pyroligneous acid. Remsen (SACCHARIN IN PRESENCE OF SALICYLIC ACID). Ethe- real extract is evaporated, the residue dissolved in water, neutralized with soda, and mercuric nitrate added in slight excess. The ppt. is tested for saccharin, after drying, by Boernsteiris method. Renard (PEANUT OIL). Test depends upon isolation of arachic acid (melting-point 74 to 75 C.) in the form of the lead salt, which can be separated from lead oleate by extraction with ether. For details see Chem. Ztg., 1895, p. 451. Renaut (GLYCERIN HEMATOXYLIN). To a sat. solut. potassa alum in glycerin add a sat. solut. of hematoxylin in 90-% alcohol drop by drop, so as to form a deeply colored solut. Expose to daylight for a week, then filter. This solut., like Renaut 's hematoxylic eosine, may be used for mounting un- stained sections, which after some time absorb the color from the liquid and become stained. Renaut (HEMATOXYLIC EOSINE). 30 Cc. cone. aq. solut. eosine, 40 Cc. sat. alcoholic solut. hematoxylin (which has been kept for some time and pptd.), and 130 Cc. sat. solut. potassa alum in glycerin (sp. gr. 1.26). Stand for 5 or 6 weeks in a partially covered vessel, protected from dust, until alcohol is evap- orated, then filter. The filtrate can be diluted with glycerin if desired. Mount objects in this fluid diluted with i or 2 volumes glycerin, or stain separately for some days or weeks, and mount in balsam, after washing in alcohol charged with a. sumcient quantity of eosine. TESTS AND REAGENTS. 251 Renaut (SILVER METHOD). For the study of lymphatics stain tissues with a i-% solut. of AgNO 3 mixed with (i) 3 or 4 parts of a mixture of 80 parts sat. solut. picric acid and 20 parts of a i-% osmic acid solut., or (2) with 4 parts of a mixture of 4 parts picric-acid solut. and 20 of osmic-acid solut., with or without the addition of i % acetic acid to the mixture. Renzone (KAIRIN IN URINE). Add solut. Fe 2 Cl 6 . A dark- violet or reddish-brown color develops changed by H 2 SO 4 to light-red. Reoch (OXALIC ACID IN URINE). Calcium oxalate is pptd. on the addition of alcohol. Resegotti-Martinotti (SAFRANINE-METHOD). See Martinotti- Resegotti. Reuss (ATROPINE). Heat with H 2 SO 4 and some oxidizing sub-- stance odor of blossoms develops. Renter (PARA-AMIDOPHENETOL IN PHENACETIN). Melt phenac^ etin with pure chloral hydrate a violet color indicates pres- ence of amidophenetol. (Even the purest commercial speci- mens show a slight rose tint.) Reynold (ACETONE IN THE URINE). Shake distillate from urine with freshly pptd. HgO (from HgCl 2 and KOH). If acetone present, the filtrate will contain acetone-mercury in solution and will respond to tests for mercury. Reynold-Gunning (ACETONE IN URINE). Add recent yellow mercury oxide to urine, filter, and overlay filtrate with ammo- nium sulphide black ring of mercury sulphide forms. Reynoso (IODINE). Heat mixture of barium peroxide, water, starch paste, and HC1 until gas begins to evolve, then add the. liquid a blue color develops if iodine present in latter. Rheoch (FREE MINERAL ACIDS). See Mohr's test. Rhien (FIXED OILS IN ESSENTIAL OILS). Pass steam through the oil till it distils over, and shake residue with ether, which will take up fatty matter. Ribbert (CAPSULE STAIN). Immerse cover-glass preparation rapidly in Ribbert 's solut. and immediately rinse in water. Bacilli stain dark, while the capsules are light blue. Rice (CARBOLIC ACID). Place 10 Gm. KC1O 3 in a test-tube,, cover with an inch layer of HC1, and add i volumes of water. After removing most of the gas evolved, by blowing through- a glass tube, pour NH 3 cautiously on the surface of the mix-. TESTS AND REAGENTS. ture, and then a few drops of the suspected liquid. If carbolic acid present the ammoniacal layer will be brown to rose-red. Richardson (NAPHTOL). Dissolve 0.04 Gm. naphtol and 0.5 Cc. of normal NaOH solut. in i or 2 Cc. water, then add 0.05 Gm. of sulphanilic acid dissolved in 5 Cc. of normal NaOH solut., and 0.02 Gm. NaNO 2 dissolved in 5 Cc. normal H 2 SO 4 . Under those conditions a-naphtol gives a dark blood-red color, changing to brown on adding diluted H 2 SO 4 ; /?-naphtol de- velops a reddish-yellow color. Richardson (SERUM PAPER). Paper saturated with the serum of typhoid patients and dried may be used for W idol's reac- tion instead of fresh serum. Riche-Bardy (METHYL ALCOHOL IN ALCOHOL). Mix 10 Cc. of the sample 15 Gm. iodine and 2 Gm. amorphous phosphorus, and distil the iodides into 30 Cc. water. Separate and mix with 5 Cc. aniline, kept cool in a flask; after an hour add water and excess of NaOH and boil. Take i Cc. of the oily layer which rises to the surface and mix with 10 Gm. of a mix- ture of clean sand, 100 parts; salt, 2 parts; copper nitrate, 3 parts; heat in a glass tube to 90 C. for 8 hours, then exhaust with warm alcohol, filter, and make up to 100 Cc. with more alcohol. If no methyl alcohol is present the color is red, if a trace of methyl alcohol is there the tint will be more or less violet, and will give a standard color to a skein of white wool. Richmond (NITRIC ACID). Mix solut. to be tested with cone. H 2 SO 4 and when cool overlay on cone. FeSO 4 solut. The presence of HNO 3 is indicated by a reddish color changing to purple and brown. Also called Desbas sin's reaction. Richmond-Boseley (FORMALDEHYDE). Fluids containing for- maldehyde when boiled with a solut. diphenylamine in water and the necessary volume H 2 SO 4 , yield a white flaky ppt. Presence of HNO 3 or nitrates is indicated by the resulting green color. See Hehner's reaction. Richter (INDICATOR). Potassium dichromate. Gives with al- kalies a reddish-yellow color ; with acids a pale-yellow. Rideal (ANTIMONY, ARSENIC, AND TIN). These elements in minute quantities are detected by means of electrolytic couples of platinum-iron, copper-platinum, and zinc-gold. See Chemical News, LI, p. 292. TESTS AND REAGENTS. 25$ Rideal (HYDROLYSIS OF BUTTER FAT). Heat melted butter with H 2 SO 4 , and then after destroying the H 2 SO 3 formed by permanganate, distil off the volatile fatty acids, which titrate as in the Reichert-Meissl process of butter analysis. (See Analyst, xvm, p. 165.) Rideal-Green (NITROUS ACID). A volumetric method based upon the diazo reaction with aniline. Determinations of HNO 2 with less than 0.1% error can be made even in presence of reducing agents when permanganate is obviously inad- missible. See Chemical News, XLIX, p. 173. Rideal-Rosenblum (COMPOUNDS OF CHROMIUM). A method based upon fusion with sodium peroxide. For precautions- and details necessary in order to insure accurate results, see Journ. Soc. Chem. Ind., 1896, p. 1017. Ri deal-Stewart (TOTAL PROTEIDS). By precipitating an aque- ous solut. of a meat extract by chlorine, a ppt. of constant composition is obtained, which can be dried over sulphuric acid or kjeldahled. (See Analyst, Aug., 1897.) Ridenour (SALICYLIC ACID). H 2 O 2 in the presence of an am- moniacal solut. of ammonium carbonate affords a red varying; in intensity according to quantity of salicylic acid present. For details see MERCK'S REPORT, vm, p. 513. Riegel (FREE HYDROCHLORIC ACID IN GASTRIC JUICE). Moisten Congo-red paper with drop filtered gastric juice, or add drop of Congo-red solut. to latter a blue color shows presence of free HC1. Also known as Herzberg's paper. Riegler (ALBUMIN), i. Asaprol (calcium naphtolsulphonate) , 8; citric acid, 8; dissolve in distilled water, 200. 10 Cc. of urine are mixed with 10 to 20 drops of the reagent. Traces of albumin are indicated by a turbidity; larger quantities by a ppt. Quantitative determination may be made with an al- buminometer. 2. 10 Gm. /?-naphtalinsulphonic acid are well shaken with 200 Cc. water and filtered. A turbidity or ppt. on adding 20 to 30 drops of reagent to 5 to 6 Cc. of fluid in- dicates presence of albumin. Sensitiveness i : 40,000. Albu- moses and peptones react in a similar manner, but the ppt.. disappears on warming, and reappears on cooling. Riegler (ALBUMOSES AND PEPTONES). Dissolve 5 Gm. para- nitraniline in 25 Cc. water and 6 Cc. cone. H 2 SO 4 , add 100 Cc. 254 TESTS AND REAGENTS. water, then a solut. of sodium nitrite 3 Gm. in 25 Cc. water, and make up to 500 Cc. with water. Filter and preserve in the dark. Mix 10 Cc. reagent with 10 Cc. fluid to be tested, then add 30 drops io-% solut. NaOH if very small quan- tities of albumoses or peptones present a yellowish-orange color develops; with notable quantities a blood-red, even the froth on shaking being red. On now adding excess of H 2 SO 4 an orange or brownish ppt. forms. For details, see MERCK'S REPORT, ix, p. 24. Riegler (ALDEHYDES AND GLUCOSE). Heat o.i Gm. phenylhy- drazine hydrochlorate, 0.5 Gm. cryst. sodium acetate, and i Cc. sugar solut. until dissolved. When near boiling-point add 20 to 30 drops io-% NaOH without shaking in from a few seconds to 5 minutes, liquid becomes violet-red, even if not more than 0.005% sugar present. If no sugar present, color will be a slight pink. For sugar in urine, color must develop within i minute to afford physiological significance. Re- action also occurs with aldehydes, hence absence of these must be assured. According to Jolles, absence of albumin must also be assured. Reaction uninfluenced by uric acid and creatinine. Riegler (BILIARY PIGMENTS). On adding an excess of para- diazonitraniline solut. to an alkaline solut. of bilirubin or biliverdin, intensely colored reddish- violet flocks are pptd., soluble in chloroform, alcohol, or benzene, and affording reddish-violet or violet soluts. For details see MERCK'S RE- PORT, vin, p. 269. Riegler (INDICATOR). Diazoparanitraniline-guaiacol. Gives a red color with alkalies, and a greenish-yellow with acids. Riegler (NITRITES), i. 15 Cc. of the fluid to be examined are mixed in a test-tube with 0.02 to 0.03 Gm. of the naphtol rea- gent (equal parts naphtionic acid and pure beta-naphtol) and 2 to 3 drops cone. HC1, shaken, and i Cc. strong NH 3 poured down the side of the tube while held in a slanting position; presence of nitrites is indicated by appearance of a red zone, and on shaking the whole solution turns red. 2. Naphtyl- amine sulphonic acid (naphtionic acid), i Gm.; beta-naphtol, i Gm. ; sodium hydrate, 0.5 Gm.; water, 200 Cc. 10 drops of the solut. are used. TESTS AMD REAGENTS. 255 Riegler (URIC ACID). Para-nitraniline 0.5 Gm., water 10 Cc., pure cone. H 2 SO 4 15 drops. Put into a glass flask of 150 Cc. capacity and heat with agitation until dissolved. Water 20 Cc. is now added, the mixture cooled quickly, NaNO 2 solut. ( 2 -5-%) an( i 10 Cc. are added, and diluted, after 15 minutes, with water 60 Cc. The mixture is shaken up repeatedly and filtered. The formation of a blue or green color on adding the reagent and io-% NaOH solut. indicates presence of uric acid. Riegler (URIC ACID AND URATES). Add to 5 Cc. of liquid to be tested a small pinch phosphomolybdic acid, shake, then allow 10 to 20 drops cone. NaOH solut. to run in if uric acid or a urate is present, an intense blue color develops. Sensitive in dilutions of i: 100,000. Guanin, alloxan, and alloxanthin also give the reaction. Righini (MYRRH). Pure myrrh is dissolved by a solut. of an equal weight of NH 4 C1 in 15 times as much water. Riley (CHLORINE). Mix i part suspected substance, i part potassium bichromate, and 3 parts H 2 SO 4 in a beaker, and suspend in this a smaller beaker containing ice. Chloro- chromic acid is given off and condenses on the suspended beaker. On adding to the liquid a few drops NH 3 with an excess acetic acid and some solut. lead subacetate a yellow to orange color results. Rimini (ALDEHYDES). A solution of the aldehyde in alcoholic potassa is heated with hydroxylaminephenyl-sulphonic acid. This results in the formation of benzyl-sulphonic acid and a hydroxamic acid containing the aldehyde residue. The latter > compound can easily be separated, and yields an intense red- violet color with traces of iron chloride. This reaction is said to be exceedingly delicate. Rimini (FORMALDEHYDE). Add i Cc. of a i-% solut. phenyl- hydrazine hydrochlorate and 3 or 4 drops freshly prepared so- dium-nitroprussiate solut. to 15 Cc. liquid, then make alkaline with cone. NaOH, and warm if formaldehyde present, a marked blue color develops, changing to deep red. Milk thus tested turns blue to ash-gray, changing after 15 minutes to red. 256 TESTS AND REAGENTS. Rindfleisch (TUBERCLE STAIN). Heat staining solut. until, steam rises and bubbles appear on surface, then treat as in Koch-Ehrlich method. Rinnmann (ZINC). Zinc oxide moistened with cobalt-nitrate solut. and strongly heated on charcoal, affords a green color. Ripart (MOUNTING-MEDIUM). 75 parts camphor water, 75 parts distilled water, i part glacial acetic acid, 0.3 part cupric ace- tate, and 0.3 part cupric chloride. Ripart-Pettit (PRESERVATIVE FLUID). Same as mounting- medium (vide supra). Objects fixed in this stain instanta- neously with methyl green. Osmic acid or mercuric chloride may be added to increase fixing action. Ritsert (GLYCERIN). Heat i Cc. glycerin to boiling with i Cc. NH 3 , then add 3 drops 5-% AgNO 3 solut. no change should occur in the liquid within 5 minutes. Test intended to show presence of arsenous acid, as well as of acrolein and formic acid; recent investigations, however, seem to have proved the test to be fallacious. Ritsert (PHENACETIN). Boil o.i Gm. phenacetin i minute with i Cc. cone. HC1, then dilute with 10 Cc. water, filter after cooling, and treat filtrate with 3 drops 3-% chromic-acid solut. liquid gradually assumes a ruby-red color. Ritsert (SULPHONAL). Heat sulphonal with gallic or pyro- gallic acid odor of mercaptan develops. Ritthausen (PROTEIN). A violet color develops on dissolving protein in dil. H 2 SO 4 , adding excess of KOH, and then a few drops sat. solut. CuSO 4 . . Robbert-Hammarsten (THYMOL). See Hammarsten-Robbert. Roberts (ALBUMIN IN URINE). Overlay urine on solut. of NaCl containing 5% HC1 sp. gr. 1.052, or on a mixture of 5 parts sat. MgSO 4 solut. and i part of strong HNO 3 ; in both cases albumin is detected by formation of a white zone between the two liquids. Roberts (GLUCOSE IN URINE). Add a little yeast to 60 or 70 Cc. urine and let ferment 24 hours. Compare specific gravity before and after fermentation every degree lost represents i grain glucose per ounce, or 0.23%. Roberts-Stolnikoff (ALBUMIN IN URINE). Depends on em- ployment of Heller's test. TESTS AND REAGENTS. 257 Robin (ALKALOIDS). Mix i part of substance with 2 parts cane sugar and add i or 2 drops H 2 SO 4 , stirring with a glass rod. Alkaloids give colors as follows: Atr opine violet, changing to brown; codeine cherry-red, changing to violet; morphine rose, rapidly changing to violet; narcotine persistent mahogany color; quinine greenish, bright-yellow, changing to dark coffee color with yellow margin; salicin bright red; strychnine reddish, changing to dark coffee color; veratrine dark green. Robinet (MORPHINE). A neutral solut. of a morphine salt gives with a dil. solut. of Fe 2 Cl 6 containing some oxy chloride a rapidly disappearing blue color. Robinet (SALICYLIC ACID IN URINE). Ppt. urine with neutral lead acetate, remove excess of lead with dil. H 2 SO 4 , and at once add Fe 2 Cl 6 . If liquid has a red color (due to iron acetate) add H 2 SO 4 until colorless or the purple salicylic-acid color appears. Robins (GELATIN MASSES). Soak i part of gelatin in 7 to 10 parts water, and combine with one of the following coloring masses: i. Carmine coloring-mass. Rub 3 Gm. carmine with a little water and enough NH 3 to dissolve, then add 50 Gm. glycerin and filter. Then add by degrees a mixture of 5 Gm. acetic acid and 45 Gm. glycerin until slightly acid. Mix i part of this mixture with 3 to 4 parts gelatin vehicle. 2. Copper-ferrocyanide coloring mass. Mix 20 Cc. cone, solut. potassium ferrocyanide and 50 Cc. glycerin, and add slowly, with agitation, to a mixture of 35 Cc. cone, solut. copper sul- phate and 50 Cc. glycerin. At moment of injecting mix with 3 volumes of vehicle. 3. Modified Beale's Prussian-blue glycerin mass. Mix 50 Cc. glycerin and 90 Cc. sat. solut. potassium sulphocyanide, and add to mixture of 3 Cc. solut., ferric chloride and 50 Cc. glycerin. Add next a few drops HC1, and mix with 3 volumes of vehicle. 4. Cadmium col- oring mass. Dilute 40 Cc. sat. solut. cadmium sulphate with 50 Cc. glycerin, and add a mixture of 30 Cc. sat. solut. sodium sulphide with 50 Cc. glycerin, then combine with 3 volumes of vehicle. 5. Scheele' s-green coloring mass. Mix 80 Cc. sat. solut. potassium arsenite and 50 Cc. glycerin, and add 40 Cc. sat. solut. copper sulphate mixed with 40 Cc. glycerin,, and combine with 3 volumes of vehicle. 258 TESTS AND REAGENTS. Robinski (SILVER STAINING METHOD). Allow o.i- to 0.2-% solut. AgNO 3 to act for 30 seconds on objects to. be stained. Robiquet (MORPHINE). Ferric salts yield a blue color with morphine. Roch (ALBUMINOIDS). Also known as MacWilliam's reagent. Bourreau modifies this by employing a solut. of oxyphenyl- sulphonic acid 3, and .salicylic-sulphonic acid i, in water 20. Roch (ALBUMIN IN URINE). A ppt. is yielded with salicyl- sulphonic acid solut. Rochleder (CAFFEINE). On heating with HC1 and KC1O 3 (or with freshly made chlorine water) and evaporating gently, caffeine develops a yellowish-red color, changing to violet on adding NH 3 . Rogers (TIN). Ammonium molybdate affords a blue color with stannous chloride, still visible in solut. of i: 250,000. Rollett (FREEZING PROCESS). Small portions of tissue are placed on the stage of a freezing microtome after immersion in the white of a freshly laid egg, then frozen and cut with a well-cooled knife. Roman-Delluc (UROBILIN IN URINE). Shake out 100 Cc. urine with 20 Cc. chloroform after acidulating with 8 to 10 drops acetic acid. Overlay 2 Cc. of clear chloroformic solut. with 4 Cc. of i : 1,000 solut. zinc acetate in 95-% alcohol. At line of separation a characteristic green fluorescence appears if urobilin present, more easily recognized against a black background. On shaking, fluorescence is more marked, and the mixture acquires a pink tint. Romei (FUCHSINE IN FRUIT SYRUPS). Fruit syrup colored with fuchsine yields the dye to fusel oil when shaken with it. Romei (WATER IN ETHER). Well-dried K 2 CO 3 is insol. in pure ether, but forms a dense solut. with any water present. Roosevelt (!RON PYROGALLIC STAIN). Mix 20 drops sat. solut. FeSO 4 , 30 Gm. water, and 15 to 20 drops sat. solut. pyro- gallic acid. Rose (BIURET REACTION FOR ALBUMINS). The albumin solut. is rendered alkaline with NaOH and a dil. CuSO 4 solut. (17 or 1 8 Gm. in i litre water) added drop by drop with constant shaking. The solut. first becomes rose-red, then violet, and finally blue, the last appearing reddish when com- TESTS AND REAGENTS. 259 pared with normal CuSO 4 solut. See also Brueke's biuret reaction and Posner's reaction. Rosen bach (ALBUMIN). Add a few drops 5-% solut. chromic acid to a slightly acid urine if albumin present, a yellowish flocculent ppt. forms. Phosphates pptd. on boiling are re- dissolved. Rosenbach (BLOOD-CELL STAIN). Sat. aqueous solut. methylene blue 50 Cc.; sat. aqueous solut. phloxin, 20 Cc.; alcohol (95-%), 30 Cc.; water, 60 Cc. Stain is also good for all varieties of malarial parasites. Rosenbach (BILIARY PIGMENTS). On carefully adding to urine a few drops 5-% chromic-acid solut. a green color is produced, which changes to brown on adding more reagent. In Rosen- bach's modification of Gmelin's test, on filtering urine and letting a drop HNO 3 run down side of moist filter, a yellow to violet and green color results. Rosenbach (GLUCOSE AND LACTOSE). On boiling a solut. (even i: 1,000) of glucose or lactose with a little sodium nitro- prussiate and NaOH, a characteristic reddish-orange or red- brown color develops. Rosenbach (INDIGO-RED IN URINE). Boil urine and add HNO 3 drop by drop if indigo-red present a deep-red color devel- ops, and the froth on shaking is violet. The color is soluble in chloroform or ether. Rosenfeld-Silber (INDICATOR). The authors prepare a new indicator, "rubrescin," as follows: Fuse together 50 Gm. resorcin and 25 Gm. chloral hydrate in an oil-bath; at 160 C. the reaction proceeds without the necessity for further heating, HC1 being eliminated. The melt forms a crumbly, non-hygroscopic mass insoluble in chloroform, slightly sol- uble in ether, soluble in warm amylic alcohol, and in cold methyl and ethyl alcohols, as well as in water. The i-% solut. has a dark-red color, and its sensitiveness is very great, i drop of a deci-normal NaOH added to 100 Cc. water, and treated with 3 to 6 drops of the i-% solut. retains its red -color for an hour, and a red fluorescence is still visible even after standing one day. (When phenolphtalein is used under similar conditions, the color fades away in a few seconds.) A similarly excellent result is obtained with i to 2 drops of deci- 260 TESTS AND REAGENTS. normal borax solut., and normal and acid sodium-carbonate solutions. With i drop of decinormal H 2 SO 4 the color dis- appears completely when 3 drops of the indicator solution are used; when 5 to 6 drops are used the color is distinctly yellow. NH 3 too gives a red color. Rubrescin, as an indicator, must be regarded as of strongly acid character. Rosens tiehl (ANILINE). See Runge's test. Rosenstiehl (PARATOL.UIDINE). Add HNO 3 to a solut. of para- toluidine in H 2 SO 4 the latter becomes bluish- violet, then red and brown. Rosin (BILIARY PIGMENTS). If biliary pigments present a green ring forms on overlaying a few Cc. of dil. iodine solut. on the urine. Ross (PHOSPHORIC ACID). On dissolving a phosphate in a borax bead, and adding sodium tungstate, the bead becomes blue in the reducing flame. Rossbach (POISONOUS ALKALOIDS). Action of alkaloids upon infusoria is tested, and the degree of toxicity estimated from intensity of action. Rossel (BLOOD IN URINE). Acidulate urine strongly and shake with equal vol. ether. (If an emulsion forms, cool with ice- water, or add a few drops alcohol.) To ethereal solut. add a few drops water, then 15 to 30 drops old turpentine oil, or 5 to 10 drops H 2 O 2 , and shake lightly; then add 10 to 20 drops alcoholic 2-% solut. barbaloin and shake thoroughly the aqueous layer acquires a distinct red color in i to 3 minutes if traces of blood present. (Coloration said to be discernible even when traces no longer detected spectroscopically.) Roth (FIXED OILS). H 2 SO 4 (sp. gr. 1.4), saturated with nitrous fumes is mixed with the olive or other oil to be tested, and the color and solidifying-point noted. See Poutet's elaidin test. Rouget (METHYLENE-BLUE METHOD). Modify Dogiel's proce- dure by employing for muscles of Batrachia a 0.5-% solut. methylene blue in o.6-% salt, solut. Rouget (SILVER STAINING). Expose tissues repeatedly to the action of weak AgNO 3 solut. (i : 750 or 1,000), and wash with water after each bath. Reduce in glycerin. TESTS AND REAGENTS. 261 Housselet (PRESERVATION OP ROTIFERS). Place water con- taining the Rotifers in a watch-glass, and add at intervals a few drops of mixture containing 3 parts 2-% cocaine hydro- chlorate solut., i part methylated spirit, and 6 parts water. When the cilia cease to beat, add a drop Flemming's liquid or of 0.25-% osmic acid-solut., and after that has acted for not more than half a minute, remove the Rotifers with a pipette, and wash them by passing 2 or 3 times through distilled water in watch-glasses. Finally, mount in a mixture of 2.5 parts formaldehyde and 37.5 parts dist. water. Houssin (CRYSTALS). Ruby-colored crystals, reflecting dark blue, separate gradually from the oily mass obtained on mix- ing solutions of nicotine and iodine in ether. Hoyere, De la (FIXED OILS). A red color develops on treating a few drops oil with 2 drops fuchsine solut. to which just enough alkali has been added to decolorize it. The color is produced by the free acids in the oils, and according to Hal- phen the value of the test is limited by the fact that mineral oils may also contain acids. The acids in oils used as lubri- cators may also be neutralized by alkaline soaps, though the presence of the latter can be easily detected by the red color formed on adding a solut. of congo red just colored violet by HC1. Ruber (GLUCOSE IN URINE). See Rubner 1 s test. Rubner (GLUCOSE). A red ppt. forms on adding lead acetate and ammonia, then warming the solution. Rubner (MILK-SUGAR). Boil with excess of lead acetate a yellowish-brown color develops. On now adding NH 3 a brick-red color and cherry-red ppt. form. Rudisch-Boroschek (URIC ACID IN URINE). The determina- tion is made with a sat. aqueous solut. of sodium sulphite, each 100 Cc. of which contains in solution about i Gm. of silver chloride. On adding the solution to a solution of uric acid rendered strongly alkaline with sodium carbonate, there forms a flocculent precipitate, which soon settles, and which may be readily filtered off. The precipitate has most prob- ably the composition Ag C 5 H 3 N 4 O 3 . On adding a sulphite- silver solution to urine rendered strongly alkaline with sodium carbonate, there forms a yellowish- white precipitate, which 262 TESTS AND REAGENTS. also readily separates, and which may be filtered off and washed with sodium-carbonate solution. Rudolf- Fischer (ACETANILID). Heat 5 Gm. acetanilid for some time with 5 Gm. dry ZnCl 2 a yellow coloring matter with moss-green fluorescence forms, which may be dissolved by heating with very dil. HC1. Product formed is flavanilin, C 16 H 14 N 2 . Ruempler (FREE ACIDS IN FIXED OILS). An emulsion forms on shaking the oil with a solut. chemically pure Na 2 CO 3 . NaOH must be absent. Ruggieri-Tortelli (COTTONSEED OIL). See Tortelli-Ruggieri. Runge (ANILINE), i. Aniline solut. in the absence of NH 4 C1 yields with chlorinated-lime solut. a purple-red color, which changes to rose-red on adding acids. According to Rosen- stiehl, in case the aniline is impure, ether is added after admix- ture of the chlorinated-lime solut. ; this takes up the brown product formed, so that the aqueous solut. remains of a pure blue color. 2. A pine shaving, moistened with a very dilute solut. of an aniline salt, is colored yellow. Runge (CANE SUGAR). Sugar is blackened on concentrating it with dil. H 2 SO 4 . Many other organic substances act like- wise, however. Runge (CARBOLIC ACID). A pine shaving moistened with HC1 is colored blue by carbolic acid. Rupeau (PICRIC ACID IN BEER). Ferrous sulphate, 5 Gm.; tartaric acid, 5 Gm.; water, 200 Gm. Mix solution with an equal volume of sat. solut. NaCl. Overlay i to 2 Cc. reagent on half a Cc. beer and add 2 drops NH 3 . Presence of picric acid is shown by a red color. Rust (CARBOLIC ACID AND CREOSOTE). Collodion forms a jelly with carbolic acid, but not with creosote. Ryder (DOUBLE IMBEDDING PROCESS). After the collodion bath, soak objects in chloroform, then remove into a mixture of chloroform and paraffin heated to not over 40 C., and finally into a bath of pure paraffin. Sabanin-Laskowski (CITRIC ACID). Yellow color develops on heating with excess of NH 3 in a sealed tube at 120 C. for six hours. On pouring out and allowing to stand for several hours, color changes to blue. TESTS AND REAGENTS. 263 Sabatier (COPPER). Add i drop solut. of a copper salt to i Cc. cone. HBr if much copper present, a purple-red color at once develops; if little, color is lilac. A o.oooi-% solut. of a cop- per salt still gives the reaction. A mixture of KI and H 3 PO 4 also gives the reaction, which develops on first carefully warming, then cooling. Sabatier (NITRITES). On dissolving a few fragments cuprous oxide in cone. H 2 SO 4 containing a little nitrite, the solut. is colored intensely violet to purple. All cuprous compounds, and cuproso-cupric derivatives afford the color. Cupric compounds do not react. Sabatin (COPPER). Trace of a copper salt dissolved in cone, hy- drobromic acid develops an intense purple color, i drop of a i : 30,000 copper-salt solut. added to i Cc. colorless cone, acid still affords the reaction. Reagent may be replaced by a solut. of KBr in orthophosphoric acid. Delicacy of reaction somewhat impaired by presence of free bromine; on driving off latter by heat, however, the color is observed. Sabrazes-Deniges (TEST-PAPER FOR IODINE). Boil i Gm. starch with 40 Cc. water, cool, and add 0.5 Gm. sodium ni- trite. Apply paste to both sides of heavy unsized paper. The dry paper is moistened with liquid to be tested, and moistened spot wetted with i drop io-% H 2 SO 4 if iodine (iodide) is present a blue color develops. Sachs (NUTRIENT MEDIUM). Potassium nitrate, i Gm.; so- dium chloride, 0.5 Gm.; calcium sulphate, 0.5 Gm.; magne- sium sulphate, 0.5 Gm. ; calcium phosphate, 0.5 Gm.; and a few drops of ferric-chloride solut. are dissolved in i liter of water. Sachsse (GLUCOSE). Two solutions are made, composed respectively of mercuric iodide 18 Gm., potassium iodide 25 Gm., water 500 Cc.; and KOH 80 Gm. in 500 Cc. water. Before use for titration equal volumes of the two solutions are mixed; as an indicator, paper, saturated with an alkaline solut. stannous chloride is employed. A black spot is pro- duced by a drop of the solution so long as any unreduced mercuric salt is present. Each 40 Cc. of this solution equals 0.1342 Gm. glucose. 264 TESTS AND REAGENTS. . Sacchse-Heinrich (GLUCOSE). Solut. contains only 10 Gm. 'KOH for the above quantities. The glucose solut. (about 5-%) is added to the boiling reagent until all mercury salt is reduced. As an indicator, H 2 S is used, being added to a small portion of solut. acidulated with acetic acid. 40 Cc. reagent are reduced by 0.1342 Gm. glucose. Sahli (METHYLENE-BLUE BORAX). 5-% solut. borax, 16 Gm.; sat. aqueous solut. methylene blue, 24 Gm. ; dist. water, 40 Gm. Sahli (STAINING NERVE-CENTERS). Sections of material hard- ened in bichromate are washed in water for 5 or 10 minutes and stained dark blue with cone, aqueous solut. methylene blue. They are then rinsed with water, stained for 5 minutes in sat. aqueous solut. acid-fuchsine, rinsed with alcohol, and passed - into a large quantity water. Or, instead of rinsing in alcohol, use alcohol containing from o.i to i% KOH, differentiate the stain in water, clear sections with cedar oil, and mount in balsam dissolved in cedar oil. For obtaining a specific stain of nerve-tubes, stain sections for a few minutes or hours in a -. mixture of 24 parts sat. aqueous solut. methylene blue, 16 parts 5-% solut. borax, and 40 parts water. Sections are then ' washed in water or alcohol until the gray matter can be clearly distinguished from the white, cleared with cedar oil, and mounted in balsam. Salkowsky (CARBON MONOXIDE IN BLOOD). Mix suspected blood with 19 parts water and add an equal volume NaOH (sp. gr. 1.34) if blood contains CO the mixture be- comes immediately turbid, at first whitish, then bright red; after some time red flocks separate and float on surface of rose-colored liquid. Normal blood is colored a dirty-brown by NaOH. Salkowsky (CHOLESTERIN). Dissolve a few Ctg. substance in 2 Cc. chloroform and shake solut. with 2 Cc. of cone. H 2 SO 4 . In presence of cholesterin the chloroform becomes blood-red and the acid exhibits greenish fluorescence. If test is applied as a zone reaction, a brownish-red zone appears. Breathing on chloroform solut. is said to change the red color to blue, green, and yellow. Salkowsky (CREATININE). See WeyVs test. TESTS AND REAGENTS. 265 Salkowsky (HEMATOPORPHYRIN). Ppt. urine with a solut. of Ba (OH) 2 , wash ppt., extract with alcohol containing i% HC1, and examine spectroscopically. Two characteristic bands are seen. Salkowsky (!NDOL). See Bayer's test. Salkowsky (OXALIC ACID). Make 100 Cc. urine alkaline with Ca(OH) 2 , add CaCl 2 , evaporate partially, add alcohol, wash ppt. with some alcohol and hot water, then dissolve in HC1. Next add NH 3 and acetic acid. Octahedral crystals of cal- cium oxalate are thus obtained. Salkowsky (PEPTONE IN URINE). Acidulate 50 Cc. urine with HC1, and ppt. with phosphotungstic or phosphomolybdic acid. Wash ppt., warm on water-bath, dissolve with a little NaOH, and add a few drops i- to 2-% CuSO 4 solut. In presence of peptone, a red color appears. The author amends this test, since he finds that the presence of urobilin may occasion a ppt. and give the biuret reaction like albumose; if, therefore, urobilin present, it must first be removed from the phospho- molybdic ppt. before the biuret reaction is applied. Salkowsky. (PHENOL). Phenol solut. is colored blue or greenish by NH 3 and a few drops chlorinated-lime solut., and heating gently. Salkowsky (POTASSIUM IN URINE). Evaporate 100 to 150 Cc. urine to 12 to 18 Cc., filter when cold, and add cone, solut. tar- taric acid potassium bitartrate deposits. Salkowsky (SULPHUROUS ACID IN URINE). Add 10 Cc. HC1 (sp. gr. 1.12) to 100 Cc. urine, and evaporate to 25 or 30 Cc. in a tube a bluish or yellowish white ppt. forms on upper portion of cool tube. Salkowsky-Kitasato (!NDOL IN BACTERIAL CULTURE). See Kitasato-Salkowsky. Salkowsky-Leubes (MuciN IN URINE). Treat urine with 2 vol. absolute alcohol, collect ppt. and re-dissolve in water. The solut. gives a turbidity with acetic acid insoluble in ex- cess, but soluble in HC1 or HNO 3 . Salomon (XANTHIN; PARAXANTHIN; HETEROXANTHIN). NaOH or KOH ppts. paraxanthin and heteroxanthin, the former as right-angled prisms and planes, the latter as acute or obtuse- angled, often double, crystals. Salzer (ALCOHOL IN ESSENTIAL OILS). The same as Puscher's. 266 TESTS AND REAGENTS Sandlund (IODINE IN URINE). Treat 5 Cc. urine with i Cc~ H 2 SO 4 (1:5) and 2 or 3 drops sodium-nitrate solut. (i Gm. in 500 Cc.), then shake up with carbon disulphide this becomes colored if iodine present (up to 0.001%). Sankey (STAINING NERVE-CENTERS). Stain in a 0.5-% solut. aniline blue-black, and in order to obtain a differential stain, wash out for 20 to 30 minutes in chloral-hydrate solut. Sargent (BLEACHING METHOD). Soak insects to be bleached for a day or two in a mixture of HC1 10 drops, potassium chlo- rate 30 grains, water i fl. ounce. Wash well. Sattler (SILVER STAINING). Preparations stained with AgNO 3 are exposed to light for a few minutes in water acidulated with acetic or formic acid. Saul (ESERINE). If a solut. of eserine, or one of its salts, be heated to boiling, and a few drops of strong HNO 3 added, an orange-colored liquid is obtained, which, on adding NaOH in excess, yields an intensely violet solut. The violet color is changed to pale-orange by acids, and restored by alkalies. Saul (TANNIN). To about 0.015 Gm. tannin in 3 Cc. water add 3 drops of 20-% alcoholic solut. thymol, and then 3 Cc. strong H 2 SO 4 gallotannic acid yields a turbid rose-colored solut.; gallic acid remains practically uncolored. Savalle (FUSEL OIL IN ALCOHOL). Heat alcohol with an equal vol. cone. H 2 SO 4 until boiling commences fusel oil is indicated by the formation of a brown color; all aldehydes and even higher alcohols give this reaction. If the latter are to be tested for, the aldehydes may be removed by heating for half an hour with a little metaphenylenediamine hydrochlo- rate and subsequent distillation ; the distillate thus freed from aldehydes is tested with H 2 SO 4 . If the quantity of fusel oil is slight, 10 to 20 drops of a i : 1,000 solut. furfurol maybe added, and then a pink color is developed, if higher alcohols present, on heating with H 2 SO 4 . Test may be employed quantitatively for the colorimetric determination of fusel oil. Schaal (INDICATOR). Alizarine is colored yellow by acids, and rose-red by alkalies. Schacht (BENZOIC ACID). The acid from Siam benzoin decol- orizes an alkaline solut. KMnO 4 , but that from other sources merely alters the color to green. TESTS AND REAGENTS. 267 Schack (PEPPERMINT OIL). A blue-green color is given with fused salicylic acid; on dissolving mixture in alcohol the solut. is blue by transmitted, and red by reflected, light. Schaefer (CINCHONIDINE IN QUININE SULPHATE). Dissolve i Gm. quinine sulphate in 9 Gm. absolute alcohol and 3 Gm. 5-% H 2 SO 4 . After standing for a day with occasional shak- ing, any cinchonidine present will have pptd. as tetrasulphate r that salt being only slightly soluble in alcohol^ By dissolving in water and pptng. again with NaOH, the cinchonidine can- be obtained pure (m.p. 199 C.). Schaefer (MARTIUS' YELLOW IN PASTRY). Heat 200 Gm. pas- try with 50- to 6o-% alcohol, concentrate by evaporation, and add HC1 if Martius' yellow present, a whitish, floccu- lent ppt. of dinitro-alphanaphtol forms, soluble in ether with yellow color. If naphtol-yellow (a sulpho-derivative of Martius' yellow) present HC1 gives no ppt., but NaOH does. Schaefer (NAPHTOL-YELLOW IN PASTRY). 10 to 20 Gm. ma- terial to be tested are broken up into crumbs and warmed with 40 Cc. alcohol (50 to 60% by vol.) naphtol-yellow colors the alcohol yellow; on adding HC1 this color disappears, while that produced by saffron would remain ; metanil-yellow is colored red. Schaefer (NITRITES IN URINE). Decolorize 3 or 4 Cc. urine with animal charcoal, then treat with an equal volume acetic acid (i : 10), and 2 drops 5-% potassium ferrocyanide solut. nitrites cause a yellow color. Schaefer (QUININE SULPHATE). Oxalate test. Dissolve i Gm. crystallized (or 0.85 Gm. anhydrous) quinine sulphate in 35 Cc. boiling water, add a solut. of 0.3 Gm. crystallized neutral potassium oxalate in 5 Cc. water, and distilled water to make up 41.3 Gm. Place the vessel in a water-bath heated to 20 C. for half an hour, shaking occasionally, and filter through glass wool. On adding a drop NaOH solut. to 10 Cc. filtrate no turbidity is produced if the quinine sulphate is free from allied alkaloids. Schaeffer (DIFFERENTIATING BOILED FROM UNBOILED MILK). Add i drop 0.2-% H 2 O 2 and 2 drops 2-% solut. paraphenylene- diamine to 10 Cc. milk, and shake unboiled milk is imme- diately colored blue. 268 TESTS AND REAGENTS. Schaellibaum (SERIAL SECTIONS). Attach sections to slides by the aid of a mixture of i part collodion and 3 or 4 parts clove or lavender oil; spread thinly with a small brush. After arranging the sections, heat gently until the oil has evap- orated. Schaer (BLOOD). See Huehnef eld's turpentine solution. Schaer-van Ankum (CHLORAL ALCOHOLATE IN CHLORAL HY- DRATE). Treat i Gm. chloral hydrate with i Cc. HNO 3 (sp. gr. 1.38) no yellow color or vapors should result at ordinary temperature or on heating, in the course of 10 minutes. Schaerge (COCAINE). Dissolve 0.02 Gm. substance in i drop water, and add i Cc. cone. H 2 SO 4 . To this add i drop potas- sium chromate or bichromate solut. a rapidly disappearing ppt. forms; on heating, the yellowish-red solut. becomes green. Schaffgot (MAGNESIA). By using a solut. of 235 Gm. ammo- nium carbonate and 180 Cc. NH 3 (sp. gr. 0.92) in i liter, magnesia can be pptd. without addition of fixed alkalies. Scheele (ARSENOUS ACID). A solut. copper sulphate in excess of NH 3 affords a light-green ppt. with an arsenite.. Scheibler (ALKALOIDS). Phosphotungstic acid or its sodium salt affords ppts. similar to those thrown down by phospho- molybdic acid. Prepare reagent by adding 100 Gm. sodium tungstate to 60 to 80 Gm. sodium phosphate in 500 Cc. water acidulated with HNO 3 . Otto simply adds phosphoric acid to a solut. sodium tungstate. See Sonnenschein' s , Jungman's, and De Vrifs tests. Schell (COCAINE). Mix cocaine hydrochlorate with calomel, and moisten or breathe on mixture latter is blackened by partial reduction of calomel. See Lenz's reaction for pilocarpine. Schenk (CARBOLIC FUCHSINE). Stain is prepared by dissolving i Gm. fuchsine and 5 Gm. crystallized carbolic acid in 10 Gm. alcohol and 100 Gm. dist. water. Or, a 5-% aqueous solut. of carbolic acid may be saturated with cone, alcoholic solut. fuch- sine, saturation being indicated by formation of a metallic- looking pellicle on surface of the liquid. The stain is washed out with alcohol followed by clove oil. Schenk (FIXING FLUID). Solut. uranium acetate is used, its properties resembling those of picric acid. It has a mild fix- TESTS AND REAGENTS. 269 ing action and a high degree of penetration, and may be com- bined with methyl green. Scherer (HYDROGEN PHOSPHIDE). Test for PH 3 in excreta in phosphorus poisoning depends upon Hager's test (q. v.), by means of silver-nitrate paper. Scherer (!NOSITE). Evaporate aqueous solut. almost to dryness with HNO 3 , and treat residue with NH 3 and a trace of CaCl 2 . On further concentration a rose-red solut. results. Scherer (LEUCINE). Carefully evaporate leucine with HNO 3 to dryness on platinum foil, and warm residue with NaOH a yellow liquid remains, which on further heating contracts to an oily, non-adhering drop. Scherer (PHOSPHORUS). A black stain forms on heating the sub- stance to 30 to 40 C., and exposing a slip of silver-nitrate test-paper to the vapors given off. See Hager's test for phos- phorus. Scherer (TYROSIN). i. On evaporating substance carefully with HNO 3 there form oxalic acid and nitrotyrosin ; latter is colored deep red-brown by KOH and NH 3 . 2. On heating tyrosin on platinum foil with HNO 3 (sp. gr. 1.2), tyrosin dis- solves with bright orange-yellow color, and on evaporating leaves a shining, transparent, deep-yellow residue, soluble in NaOH with reddish-yellow color. This solut. on evaporation leaves a deep blackish-brown residue. Schering (ALKALOIDS). Phospho-tungstic acid is used as a pre- cipitant. See Scheibler's test. Schering (!ODATES IN IODIDES). A yellow zone forms on add- ing to the solut. a crystal of tartaric acid. Schering (UROTROPIN IN URINE). Urotropin affords a char- acteristic reaction with a saturated bromine solution (bromine 10 parts and distilled water 90 parts). Several drops of this. solution added to a non-albuminous urine containing uro- tropin, develops an orange-yellow ppt. which is dissipated on lightly striking the test-tube, and reforms with an excess of reagent. The test must be carried out in the cold; when warm, the precipitate is not produced with an excess of bro- mine water. The urine may be filtered through animal char- coal before testing for urotropin. Albuminous urine gives with bromine water a precipitate which becomes yellowish TESTS AND REAGENTS. with a large excess of reagent ; this precipitate might be con- founded with that caused by urotropin, with which it presents certain analogy. It is hence important to first remove the albumin before making the test. Furthermore, a precipitate caused by urotropin is soluble on heating; that caused by albumin coagulates. :Schermer (SANTONIN). Slowly heat together a few granules santonin and a few Mg. powd. potass, cyanide, in a porcelain capsule when mass melts, a red color develops which rapidly changes to brownish-yellow. With water the fused mass gives a fluorescent solut., brown by transmitted and green by reflected light. Schiefferdecker (DIGESTION FLUID). Macerate pieces of tissue epidermis for 3 or 4 hours at about 37 C. in a sat. aqueous solut. of pancreatin. Schiefferdecker (METHYL MIXTURE). Methyl alcohol, 5 Cc.; glycerin, 50 Cc.; distilled water, 100 Cc. Mixture is used as a dissociating fluid for retina and central nervous svstem. Several days are required for complete dissociation. Schiff (ALDEHYDES). Reagent employed is fuchsine-sulphurous acid. See Guy on' s test. Schiff (CHOLESTERIN). i. A red color appears on treating cholesterin with cone. H 2 SO 4 , or evaporating with HNO 3 and then adding NH 3 . 2. A violet color develops on adding a mixture of 2 vol. H 2 SO 4 or HC1 and i vol. of dil. Fe 2 Cl 6 solut. and heating. On evaporating, a violet residue is left. 'Schiff (GLUCOSE AND CARBOHYDRATES). Saturate papers with a mixture of equal volumes acetic acid and xylidin with a very little alcohol. Heat substance to be tested with H 2 SO 4 if glucose present furfurol forms, the vapors of which color the test-paper red. Schiff (SULPHUROUS ACID). A gray stain appears on exposing mercurous-nitrate test-paper to vapor of H 2 SO 3 . Schiff (TEST-PAPER FOR PHOSPHORUS, ARSENIC, CHROMATES, AND URIC ACID). Paper impregnated with silver-nitrate gives a black color with phosphorus, a red with chromates, a yellow with arsenic, and a brown with uric acid. TESTS AND REAGENTS. 271 Schiff (UREA). Treat a solut. of urea (urine) with furfurol and HC1 a violet color develops, and later an insoluble brown mass deposits. Schiff (URic ACID). An alkaline uric-acid solut. reduces AgNO 3 or Ag 2 CO 3 . Moisten filter-paper with AgNO 3 solut., touch moistened spot first with a little dil. NaCO 3 solut., and then with the solut. to be tested a yellow spot appears if uric acid present. 'Schimmel (CORIANDER OIL). This oil must afford a clear solut. with 3 parts 70-% alcohol (by volume); oil cedar, turpentine, etc., are insoluble in alcohol of this strength. iSchimmel (LEMON OIL), i part oil must give with 10 parts 80- % alcohol (by volume) a clear or at most slightly opal- escent solut. which should not deposit even on long standing. If fatty oils present, mixture will be cloudy, and oil drops will deposit in about 12 hours; if petroleum or kerosene present, these will settle to the bottom. Schimmel (MENTHOL IN PEPPERMINT OIL). Heat about 20 Gm. oil and 30 Cc. normal alcoholic NaOH solut. in a flask with reflux condenser for i hour, then titrate uncombined alkali with normal H 2 SO 4 , using phenolphtalein as an indi- cator. Each Cc. of alkali used equals 0.156 Gm. menthol (which exists as ester, i. e., combined menthol). The saponi- fied oil is then washed with water till free from alkali, and .next boiled for i hour with an equal vol. acetic anhydride, and 2 Gm. anhydrous sodium acetate. The product is washed first with water, then with very dilute NaOH solut., dried with anhydrous sodium sulphate, and filtered. From 8 to 10 Gm. of this acetylized oil then saponified with 50 Cc. alcoholic NaOH as before, and the uncombined alkali titrated with normal H 2 SO 4 . Then, if S = weight of acetylized oil, A= the number of Cc. NaOH solut. used, P = % of total menthol, P = S-(AXo.o42)' -Schindelmeiser (NICOTINE). Add a few drops 30-% formalde- hyde free from formic acid to non-resinified nicotine, then add i drop cone. HNO 3 solut. acquires an intense, pink color. 272 TESTS AND REAGENTS. If much nicotine present, solut. is dark-red; if nicotine resinified, color is blood-red. Schlagdenhauffen (ALKALOIDS). A black color forms on treat- ing alkaloids with an aqueous solut. pyrogallic acid to which an alcoholic solut. of HgCl 2 has been added. Schlagdenhauffen (DISTINGUISHING ALKALOIDS FROM GLUCO- SIDES). Equal parts of 3-% guaiac-resin solut. and a sat. solut. HgCl 2 . Only alkaloids give a ppt. with this reagent in the cold, or, at from 60 to 79 C., a blue color. Schlagdenhauffen (MAGNESIUM SALTS). A brownish-red color or ppt. forms on adding a golden-yellow solut. of iodine in 2-% NaOH or KOH. Schlickum (ARSENIC). Overlay suspected solut. upon a solut. 0.02 Gm. sodium sulphite and 0.4 Gm. stannous chloride in 3 to 4 Gm. of cone. HC1 a yellow zone forms if arsenic present. Schlickum (INDICATOR). Cochineal tincture is recommended as an indicator in titrating phosphoric acid. Schlienkamp (Nux VOMICA). A crimson color, disappearing on cooling, develops on adding a little H 2 SO 4 and evaporating. Schlossberger (TEXTILE FIBERS). Cone, ammoniacal solut. of freshly pptd. and still moist nickelous-hydroxide. The solut. dissolves silk, but neither wool nor cotton. Compare with Persons test. Schmans (STAINING NERVOUS TISSUE). Use English blue-black in 0.25-% solut. in 50-% alcohol, with addition of a little picric acid. Stain sections for an hour. Schmatolla (TIN). Dip a glass or porcelain rod into a solut. of tin in cone. HC1, and introduce into a colorless Bunsen flame an intense bluish- white flame denotes presence of tin. Sb does not interfere with reaction. As, if present in more than equal quantity, prevents the color and leaves the rod coated with a dark layer of As and Sn. Schmid (METALLIC SALTS). A solut. of phosphorus in carbon disulphide throws down colored ppts. when shaken with aqueous solut. of the salts. Schmidt (GLUCOSE). Ammoniacal lead-acetate solut. causes a brownish-red ppt. upon warming with diabetic urine or other glucose solutions. Cane sugar does not cause the reduction. See Runner's test. TESTS AND REAGENTS. 273 Schmidt (NITRIC ACID). Mix solut. to be tested with an equal vol. of solut. of 20 drops aniline, 10 Gm. dil. H 2 SO 4 , and 90 Gm. water, and overlay this mixture upon cone. H 2 SO 4 if HNO 3 present, a light- to dark-red zone forms. Schmidt (SACCHARIN). Shake out strongly acidulated liquid three times with a mixture of equal vol. ether and petroleum ether, treat extracts with NaOH, evaporate to dryness, and heat residue for half an hour to 250 C. Then dissolve mass in water, acidulate with H 2 SO 4 and shake out with ether. If saccharin present it is found in the ethereal extract as salicylic acid, which, after evaporation of the ether, can be identified by means of Fe 2 Cl 6 . Schmidt-Donath (RESIN IN WAX). See Donath-Schmidt. Schmiedeberg (GLUCOSE). CuSO 4 , 34.634 Gm.; water,' 200 Cc. mannite, 15 Gm.; water, 100 Cc. NaOH solut. (sp. gr. 1.145), 400 Gm. Mix solutions, and add water to make 1,000 Gm. Used like Fehling's solut. Schneider (ACETO-CARMINE). Add carmine to boiling 45-% acetic acid until saturated, and filter. A drop of the cone, solut. may be added to a fresh preparation under the cover- glass, but for slow staining dilute to i-% strength. Schneider (ALKALOIDS). Mix a few Mg. of substance with 6 to 8 parts sugar on a porcelain plate and add i drop of cone. H 2 SO 4 morphine or codeine causes a fine purple-red to violet- green color, which gradually changes to dingy yellow. Addi- tion of water causes rapid decoloration. Aconitine is the only other alkaloid that may be mistaken for morphine or codeine by this test. Reaction depends on formation of furfurol, and may hence be obtained by use of furfurol and H 2 SO 4 . Schneider (ARSENIC). Separate arsenic as arsenous chloride, by distillation with HC1 and Fe 2 Cl 6 , then identify by Marsh's test. Schneider (BENZOIC ACID). Same as Schacht's test. Schneider (BISMUTH). 3 parts tartaric acid and i part stannous chloride dissolved in sufficient KOH solut. gives a black ppt. upon warming with a bismuth salt. Schneider (CODEINE). Dissolve codeine in cone. H 2 SO 4 , warm lightly, and add 2 or 3 drops cone, solut. cane sugar a purple- 1 red color develops. 274 TESTS AND REAGENTS. Schneider (FOREIGN [CRUCIFEROUS] OILS IN OLIVE OIL). Dis- solve oil in 2 parts of ether, add 5 Cc. sat. alcoholic solut. AgNO 3 , set mixture aside for 12 hours in a dark place if oils containing sulphur are present, the mixture darkens. Schneider (POTASSIUM CYANATE IN POTASSIUM CYANIDE). Test depends upon the formation of the ultramarine-blue coblat cyanate. From the potassium-cyanide solut., as cone, as possible, the HCN is removed by means of CO 2 , the K 2 CO 3 pptd. by the addition of alcohol, and the nitrate then tested with cobalt-acetate solut. Schoenbein (BLOOD). Tincture of guaiac resin and oil turpen- tine. See Almen's test. Schoenbein (COPPER). A solut. of a copper salt yields a blue color on adding potassium cyanide and tincture of guaiac. Schoenbein (HYDROCYANIC ACID), i. Filter-paper dipped in 10% tincture guaiac and dried, then moistened with o.i-% CuSO 4 solut., turns blue in the presence of HCN. See Payer's test. 2. Mix suspected liquid with 5 parts fresh, defibrinated blood and 45 parts water, then add a little H 2 O 2 . In the pres- ence of HCN the red color is changed to brown. Schoenbein (HYDROGEN DIOXIDE), i. A blue color appears on adding a little cadmium-iodide starch paste and a little ferrous sulphate. See Boettger's test. 2. Freshly prepared tincture of guaiac and a few drops cold prepared infusion of malt give a blue color. 3. A mixture of Fe 2 Cl 6 and potas- sium ferricyanide solut. also produces a blue color. Schoenbein (NITROUS ACID), i. On adding to potable water containing nitrous acid, a solut. of pyrogallic acid and a little dil. H 2 SO 4 , a brown color forms. 2. Add to water sufficient indigo solut. to color it deep blue and a little HC1, then while stirring add sufficient potassium pentasulphide to cause the blue color to disappear, and filter. On adding the suspected water or solut. of nitrite, the blue color reappears. Schoenbein (NITRIC AND NITROUS ACIDS IN URINE), i. Po- tassium-iodide starch paste faintly acidtilated with H 2 SO 4 is colored deep blue by slightest trace of nitrous acid. 2. An acidulated solut. containing pyrogallic acid is colored deep blue by nitrous acid, with evolution of nitrogen oxide gas. If test is carried out in a flask, the gas is converted into hypo- TESTS AND REAGENTS. 275 nitrous acid on contact with air, and would color potassium- iodide starch paper blue, or would decolorize indigo paper. Schoenbein (OZONE TEST-PAPER). Filter-paper saturated with potassium-iodide starch paste (10 parts starch, 200 parts water, and i part potassium iodide). Ozone turns this paper blue. Schoenbein- Pagenstecher (HYDROCYANIC ACID). See Schoen- bein 1 s test. Schoenn (COBALT). Neutral sodium-sulphocyanide solut. gives a blue color. Schoenn (HYDROGEN DIOXIDE). A yellow to deep-red color develops on adding titanic acid solut. Schoenn (MOLYBDIC ACID). A blue color develops on heating with H 2 SO 4 and cooling. Schoenn (PHOSPHORUS). PH 3 is evolved on heating the dry substance with magnesium and adding water. Schoenn (SULPHUR). A red color appears on heating with so- dium, dissolving in water and adding solut. sodium nitro- prusside. Schoenvogel (DIFFERENTIATING ANIMAL FROM VEGETABLE OILS). Upon shaking with 6 Cc. cone, solut. borax the vege- table oils, olive oil excepted, are said to form emulsions, while the former separate out sharply upon standing. Schoenvogel (FOREIGN FATS IN BUTTER). Shake together 6 Cc. of a sat. borax solut. and 5 drops butter at room tem- perature, or warm to melting-point of the fat. Butter, beef tallow, olive oil, and mutton tallow are said not to emulsify when so treated; all other fats do. Schonteten (ALOES). A cone, solut. borax gives a distinct green fluorescence with extract aloes, barbaloin, capaloin, and soca- loin, but not with nataloin. Schott (WHITE-LEAD PAPER [POLKA-PAPER]). A sized paper coated with white lead, used as an indicator in titrating solu- tions of metallic salts with sodium sulphide. Schotten-Baumann (ALCOHOLS AND AMINES). Reagent is ben- zoyl chloride. See Baumann's test. Schramm (OILS). When fixed oils are mixed with essential oils, a characteristic odor is given off on burning with a wick and blowing out the flame. 276 TESTS AND REAGENTS. Schreiber (SUGAR IN URINE). Cupric sulphate, 2; sodium sal- icylate, 2; sodium carbonate, 2; dist. water, 88. On boil- ing 5 Cc. reagent in test-tube the ppt. formed is gray to black;, on boiling with equal quantity saccharine urine, ppt. is dirty green with yellowish deposit on sides of tube. If more urine added, reduction is completed, and the whole precipitate is, yellow. Schreiner-Kremers (SPEARMINT OIL). Treat oil with hydroxyl- amine, drive off volatile matter with steam, and dry and weigh resulting carvoxime. Reaction is as follows: C 10 H 14 O + H 2 NOH = C 10 H 14 . N - OH + H 2 O. See also Kremers-Schreiner. Schreiter (GLUCOSE). A red ppt. is thrown down on adding a mixture of 2 parts sodium salicylate, 2 copper sulphate, 10 soda (? caustic), and 40 water. Schroeder (ACETANILID IN THE PHENACETIN). Boil 0.5 Gm. phenacetin with 6 to 8 Cc. water, cool, filter off the crystallized phenacetin, boil filtrate after adding KNO 3 and dil. HNO 3 , add a few drops Plngge's reagent, and boil again. If acetanilid present, a red color appears. Schuchardt (HYDROCHLORIC ACID IN THE GASTRIC JUICE). Reagent is a cone, alcoholic solut. tropaeolin. See also Van der Velden's test. Schuetzenberger (ANTHRAQUINONE). A red color develops on: adding an alkaline solut. of sodium thiosulphate. Schulten-Wetzlar (URIC ACID). NH 3 ppts. uric acid so com- pletely from urine that addition of an acid gives no further ppt. Schultze (ALKALOIDAL REAGENT). Phosphoantimonic acid. Prepared by dropping antimonic chloride into aqueous phos- phoric acid, or by mixing 4 parts of a sat. sodium-phosphate solut. with i part of antimonic chloride. With alkaloids, this reagent, like phosphomolybdic and phosphotungstic acids, yields white ppts. generally. See Jungmann's, Scheibler' s , . Sonnenschein's, and De Vrij's tests. Schultze (ALBUMIN). Upon adding a trace of sugar to a solut. albumin in moderately cone. H 2 SO 4 and warming to 60 C., a beautiful bluish-red color appears (furfurol reaction). See RaspaH's reaction. Schultze (AMMONIA). Chlorinated-lime solut. and carbolic acid: produce a green color. TESTS AND REAGENTS. 277 Schultze (CELLULOSE), i. Dissolve 25 parts anhydrous zinc chloride and 8 parts KI in 8.5 parts water, then add as much iodine as will dissolve on slightly warming. 2. Squire's formula: Evaporate 100 Cc. solut. zinc chloride B.P., to 70 Cc., and dissolve in it 10 Gm. KI; then add 0.2 Gm. iodine and shake at intervals till saturated. 3. Dissolve zinc in pure HC1, evaporate in presence of metallic zinc to syrupy consistency, then saturate with KI and I. Pure cellulose is colored blue with this reagent. Schultze (IODIZED SERUM). To the fresh amniotic liquid of mammals add iodine and agitate frequently during some days. Or, mix serum with a large proportion tincture iodine and filter. Add a little of this every 2 or 3 days to the serum intended for use. Schultze (MACERATING MIXTURE). Place sections in HNO 3 (sp. gr. 1.2) and add 2 to 3% potassium chlorate. Leave for several hours in the cold; solution of the middle lamella may also be attained in a few seconds by warming gently until gas is given off freely. Afterwards wash tissue in water, trans- fer to a slide, and complete disintegration with needles. Schultze (MOUNTING MEDIUM). A nearly sat. aqueous solut. potassium acetate. Schultze (STAINING BACILLI). Stain sections and cover-glass preparations for some hours in aqueous methylene-blue solut., differentiate in 0.5-% acetic acid, dehydrate in alcohol, clear in cedar oil, and mount in balsam. Schultzen (STRYCHNINE IN URINE). Evaporate alcoholic ex- tract of concentrated urine, make residue alkaline with KOH, and exhaust with ether. Evaporate ether, and test crystals remaining by usual tests for strychnine. Schulze (GUANIDINE SALTS). Nessler's reagent (q. v.) gives a pale-yellow ppt., at first flocculent, but becoming dense later. Schulze (NITRIC ACID IN URINE). Fe 2 Cl 6 and HC1 develop nitrous oxide in urine containing nitric acid. Schulze (SALICYLIC ACID). A neutral solut. of a salicylate yields a green color with CuSO 4 solut. Schumpelitz (VERATRINE). Upon evaporating a few drops solut. fused zinc chloride in dil. HC1 to dryness with veratrine, a red color results. 278 TESTS AND REAGENTS. Schunke-Mulder (ALOES). Concentrate mixture of i part sub- stance and 8 to 10 parts cone. HNO 3 with gentle heat, and col- lect yellow ppt. (of aloetic and chrysammic acids). Extract aloetic acid with strong boiling alcohol. It is insol. in cold alcohol, is orange-colored and crystalline, and dissolves in KOH with red color; in NH 3 with violet. Chrysammic acid is yellow, amorphous or crystalline, gives off yellow vapors on being rapidly heated, and dissolves in boiling water with purple-red color; in KOH it dissolves with decomposition, giving a black-brown solut. Its alkali salts have a gold- green, metallic color; its barium salt is red. Schuster (COLORING-MATTER IN BEER). Pure beer is said to be decolorized by tannin solut., while beer colored with cara- mel is not decolorized. Schuttleworth (GOLD IN SILVER NITRATE). Ppt. AgNO 3 with HC1, and add potassium rhodanide to filtrate if gold present, an orange-red color develops. Schtitz (ALKALINE METHYLENE BLUE). Equal parts cone, alcoholic solut. methylene blue and o.oi-% solut. KOH. Schiitz (BACTERIA STAIN). Stain in mixture of equal parts i : 10,000 KOH solut. and cone, alcoholic solut. methylene blue for 24 hours. Rinse in water containing 4 drops acetic acid, then place in 50-% alcohol for 5 min., then in absol. alcohol 15 min., then in cedar oil, and finally mount in Canada balsam. Schiitz (GoNOCOCCUS STAIN). Stain 5 to 10 minutes in a cold, sat. solut. methylene blue in 5-% filtered carbolic water; wash with water, dip in acetic-acid water (5 drops dil. acetic acid in 20 Cc. dist. water). Double stain with very dilute solut. safranin. Gonococci stain blue; pus-cells and their nuclei stain salmon-colored. Schuyten (NITROUS ACID). Antipyrine, i; acetic acid, 10. Dilute 10 Cc. of the solut. with 90 Cc. water, and to 5 Cc. of the solut. so obtained add 5 Cc. solut. to be tested if nitrous acid present a green color develops. Also known as Curtmann's reagent. Schwabe (QUININE). Potassium-cyanide solut. produces a crimson color. Schwanda (BILIARY PIGMENTS). Evaporate urine to dryness on water-bath, exhaust residue with water, filter extract, TESTS AND REAGENTS. 279 wash and dry filter-paper, and exhaust latter repeatedly with warm chloroform. Then test chloroformic golden-yellow solut. for bilirubin with HNO 3 or bromine water. Schwartz (SUGAR IN URINE). Heat to boiling 10 Cc. urine and add 5 Cc. io-% neutral lead-acetate solut.; again boil and filter while hot. Solut. NaOH is then added in sufficient ex- cess to dissolve the ppt. first formed, followed by a few grains of phenylhydrazine. The liquid is boiled for some minutes, strongly acidulated with acetic acid, and allowed to cool. If much sugar present an immediate ppt. is formed; if only traces, a turbidity appears on standing. Schwarz (SULFONAL). The odor of mercaptan is developed upon heating with charcoal. Schwarzenbach-Delf (REAGENT). Potassium platinic chloride. Schwarzenbach-Delf (ALKALOIDS). Characteristic color reac- tions result on treating alkaloids with HNO 3 and subse- quently with NH 3 . Schwarzenberg (ALKALOIDS). See Schwarzenbach-Delf. Schwanert (URIC ACID). NH 3 ppts. a further quantity of uric acid in urine from which uric acid has been previously pptd. by HC1. Schweiger-Seidel (Acio CARMINE SOLUTION). Saturate am- moniacal carmine solut. with acetic acid and filter. Stain particularly adapted for coloring cell nuclei; after staining, macerate sections in glycerin containing 0.5% HC1, then wash with acetic acid, and finally in water. Mount preparations in glycerin. Only cell-nuclei are stained. Schweissinger (ALKALIES). A solut. of equal parts of iodine and tannin in absolute alcohol produces a red color, even in very dilute aqueous solut. of alkalies or alkaline carbonates. Schweitzer (SOAP IN LUBRICATING OILS). In presence of soap, the ethereal solut. of the oil yields a white ppt. when treated with sat. solut. metaphosphoric acid in absolute alcohol. Schweitzer (TEXTILE FIBERS AND CELLULOSE), i. Freshly pptd., washed, and still moist cupric hydroxide or carbonate is shaken with 20-% NH 3 until a saturated solut. results. 2. Dissolve 10 parts CuSO 4 in 100 water, and add a solut. of 5 parts of KOH in 50 water; then wash the ppt. and dis- solve in 20-% NH 3 until saturated. This solut. dissolves 280 TESTS AND REAGENTS. cotton, linen, and silk, but not wool. Reagent is especially useful in microscopy, as it rapidly dissolves cellulose, but has no action on lignin. According to Boettger, reagent can be prepared by allowing stronger NH 3 to repeatedly run in a thin stream over copper foil. Wiesner prepares it by keeping copper turnings in contact with a 13- to 16-% NH 3 in an open bottle. Schwicker (ACETONE IN URINE). The first fraction of distillate from sample is mixed with a few drops cone. NH 3 , and a few drops decinormal iodine solution are added. A black ppt. of nitrogen iodide at first appears, but disappears on warming, and if acetone present, iodoform is formed. Scivoletto (HYDRIODIC ACID IN URINE). Dip filter-paper into starch paste, dry, sprinkle with urine, and hang in upper part of a flask containing fuming HNO 3 a blue color develops on paper. Sclavo (STAINING FLAGELLA). Leave preparations for i minute in a solut. i Gm. tannin in 100 Cc. 50-% alcohol; wash in dis- tilled water; transfer for i minute to 50-% phosphomolybdic acid; again wash, and stain for 3 to 5 minutes in a hot sat. solut. fuchsine in aniline water. Then wash in water, dry on filter-paper, and mount in balsam. Scudder-Mulliken (METHYL ALCOHOL). See Mulliken-Scudder. Seaman (GLYCERIN JELLY). Dissolve isinglass in water so as to make a jelly that remains stiff at the ordinary temperature of the room, and add one-tenth part glycerin, together with a little solut. borax, carbolic acid, or camphor water. Filter through muslin whilst warm, and add a little alcohol. Sedgwick (ALKALOIDS). Best isolated as iodosulphates. Seegen (SUGAR IN URINE). Filter urine several times through animal charcoal (to remove coloring matter,' uric acid, etc.), then apply Fehling's solut. See also Trammer's test. Seidel (!NOSITE). Evaporate the solut. to dryness with HNO 3 and treat residue with strontium-acetate solut. A violet color develops with inosite. Seller (ALCOHOL BALSAM). Heat Canada balsam until it be- comes brittle when cold, then dissolve in warm absolute alcohol and filter through absorbent cotton. This is chiefly useful as a mounting medium for objects stained with carmine. TESTS AND REAGENTS. 281 'Seller (CLEANING GLASS SLIDES). New slides or covers for microscopic objects are placed for a few hours in a mixture of 3 oz. potassium bichromate, 3 fl. oz. H 2 SO 4 , and 25 fl. oz. water. Subsequently wash with water and wipe dry with a linen rag, after draining off excess of moisture. Covers that have been used should be previously immersed for a few days in a mixture of equal parts alcohol and HC1. Old slides must be scraped free of the mounting medium before immersing in bichromate solution. Seller (DOUBLE STAIN). Stain objects with borax-carmine, wash out in acidulated alcohol, then in alcohol only, and after- stain with extremely dilute solut. indigo-carmine, prepared by adding 2 drops sat. aqueous solut. of stain to i fl. oz. alcohol, and filtering. Seivolete (IODINE IN URINE). Moisten strips of paper satu- rated with starch paste, and expose to vapors of fuming HNO 3 if iodine present in urine, paper becomes blue, o.ooooi Gm. KI may be detected by evaporating urine from paper until the latter only damp and exposing to i or 2 drops acid. Selden (SOLVENT FOR URINARY SEDIMENT). Reagent for dis- solving urinary sediment in examining for tubercle bacilli is a solut. of 4 parts borax and 4 parts boric acid in 100 parts water. See Daiber's lt Mikroskopie des Harns," p. 40. Seligsohn-Bill (CINCHONINE). See Bill-Seligsohn. Seliwanoff (FRUCTOSE OR LEVULOSE). An aqueous solut. of resorcin and fructose becomes red on being heated with HC1, and furnishes a ppt. which dissolves in alcohol with red color. Cane sugar, invert sugar, and mellitose behave similarly. See Conradi's test. Selle (AMMONIA). Filter-paper dipped in a tincture of blue hyacinth flowers and dried is colored green when exposed to NH 3 vapor. Selmi (ALKALOIDS). Two reagents are employed: i. A sat. solut. iodic acid in cone. H 2 SO 4 is diluted with 6 times its vol- ume of the same acid. 2. Lead peroxide is dissolved in cone. HC1, or glacial acetic acid, and the solut. filtered. Selmi (BLOOD). The object stained with blood is extracted with NH 3 and the liquid filtered, after which the filtrate is pptd. with sodium tungstate and acetic acid. Next wash ppt., treat 282 TESTS AKD REAGENTS, with a mixture of i volume NH 3 and 8 volumes absolute alcohol, and filter. On evaporating off the alcohol and treat- ing residue with NaCl and acetic acid, hemin crystals will appear upon microscopical examination. Selmi (MORPHINE), i. Dissolve lead peroxide in cone. HC1 or glacial acetic acid, and filter. To i drop solut. add 2 drops morphine solut. and evaporate very gently. The mixture changes from slightly yellow to bright-yellow, dark-yellow, and violet. 2. Morphine dissolved in H 2 SO 4 gives a violet color, which changes to green on saturating with NaHCO^ and adding tincture iodine. Selmi (PHOSPHORIC ACID). A green flame color is caused on applying a drop of liquid, or dry substance moistened with H 2 SO 4 , on a platinum loop, close to the lower part of a hydro- gen flame. Selmi (STRYCHNINE). Dilute a sat. solut. iodic acid in cone. H 2 SO 4 with 6 volumes of the same acid. Strychnine moist- ened with reagent is colored yellow, brick-red, and violet-red. Senator-Lehmann (GLOBULIN IN URINE). Dilute urine with water to a sp. gr. of 1.002-1.003, then add very dilute acetic acid, carefully avoiding an excess globulin is pptd. Senier (GLYCERIN). A borax bead is colored green on dipping into a slightly alkaline liquid containing glycerin, and expos- ing to the Bunsen flame. Serullas (MORPHINE). Iodic acid causes a red color. Seyda (TANNIN). Gold salts develop in dilute solut. tannin a. purple color; in very dilute solut. the color is reddish. Reac- tion best observed in neutral and faintly acid solut. Seyler-Hoppe. See Hoppe-Seyler. Shimer (Gun AND GLYCERIN JELLY). Mix equal parts glycerin jelly (FoVs second formula), Farrant's medium, and glycerin. Short- Duns tan. See Dunstan-Short. Sieben (KETOSES AND ALDOSES). Boiled for 3 hours with 7.5-% HC1, the ketoses (fructose, sorbose), are decomposed with formation of humic acid, while the aldoses (glucose, mannose, galactose), are not affected. Siebold (ALBUMIN). Add to urine containing albumin a slight excess of NH 3 , and then a slight excess acetic acid solut. becomes cloudy on heating to boiling. TESTS AND REAGENTS. 283 Siebold (ALCOHOL IN CHLOROFORM). Purple color of "a solut. iodine in pure chloroform is changed to reddish-brown by alcohol. Siebold (ARSENIC IN GLYCERIN). To 1.5 Cc. glycerin in a ; test-tube, add 5 Cc. HC1 (i : 7), i Gm. pure zinc, and a few drops solut. iodine to give a very slight yellow color. Plug the. tube with cotton-wool, and cover with filter-paper, on which a drop mercuric-chloride solut. has been dried. This should not show a yellow stain in 15 minutes. Siebold (MORPHINE). A brown color develops on heating with H 2 SO 4 and adding potassium perchlorate free from chlorate. Siebold-Bradbur^ (SALICYLIC ACID IN URINE). Add K 2 CO S to slight alkalinity, then excess of lead-nitrate solut.; shake, filter, and add a very dil. solut. Fe 2 Cl 6 a violet color will form. Siewer (MOTOR ACTIVITY OF STOMACH). Administer 2 Gm, salol in capsule or wafer with meal. In to i hour, normally, urine will react for salicyluric acid with ferric chloride. Siewert (MOLYBDIC ACID). To a solut. molybdic acid in HNO 3 , add an aqueous solut. potassium ethylsulpho-carbonate. A yellow to flesh-colored ppt. forms which soon changes to violet. Silbermann (ALBUMIN). Albumin freed from fats gives a violet color upon heating with fuming HC1. Silva, Da- (ESERINE). See Da Silva. Simon (CINNAMIC ACID). Nitrobenzene is formed on adding potassium bichromate and H 2 SO 4 . Simon (INDICATOR). Iron isopyrotritarate gives with water a solut. the red color of which is changed to violet by acids, dis- charged by an excess of acid, and changed to yellow by alkalies. The color changes are very sharp. For details see MERCK'S. REPORT, x, p. 91. Simon (GLYCOGEN IN URINE). Add 10 Cc. of 40-% KOH to 90 Cc. urine, filter, and to the filtrate add 10 Gm. KI and 50 Cc. 96-% alcohol. Glycogen is pptd. as a flocculent mass. Simon (XANTHIN). Dissolve substance in KOH or NaOH and add NaCl or CaCl 2 nitrogen is evolved, and solut. becomes blue, then brown, and finally yellow. Simons-Cramp ton (CARAMEL IN LIQUOR AND VINEGAR). See Crampton-Simons . Siringo (HYDROCHLORIC ACID IN GASTRIC JUICE). Introduce 5 Cc. gastric juice into a graduated cylinder filled with mer- 284 TESTS AND REAGENTS. ctury and dipping into a mercury bath, and then introduce a small piece sodium-nitrohydroxylamine. From the NO liber- ated the HC1 is calculated. The reaction is as follows: Skey (COBALT). A dark-red color develops on adding citric or tartaric acid, NH 3 in excess, and potassium ferricyanide. Skraup (THALLIN). An emerald-green color develops on treating thallin with oxidizers (CrO 3 , Br, I, Hg(NO 3 ) 2 , Fe 2 Cl 6 ). Slater (STRYCHNINE). A maroon-red color develops on treat- ment with H 2 SO 4 and KC1O 3 . Smith (BILIARY PIGMENTS). Modification of MarechaVs test, in which tincture of iodine is carefully overlaid on urine, and thq zone reaction observed. A greenish color develops. Smith (FREE ACIDS). AgCl is pptd. from a solut. of freshly pptd. chloride dissolved in NH 3 . Smith (SANTONIN). A greenish-yellow color develops on heat- ing with HNO 3 , and changes to deep-red with alkalies. Smith, Hopewell (DECALCIFICATION OF TEETH). Place teeth in 24 parts io-% HC1; after 15 hours add 3 parts HNO 3 , and after 48 hours add 3 parts more of the latter. After 75 to 80 hours remove the teeth and wash for half an hour in a solut. of 5 Gm. lithium carbonate in i oz. watsr. Smith-Chapman (TARTARIC AND CITRIC ACIDS). See Chapman- Smith. Smith-Chapman (UREA). Urea in alkaline solut. strongly resists, at ordinary temperatures, oxidizing action of potass. permanganate; in HC1, however, it decomposes, more readily on warming, into CO 2 and NH 3 . Smithson-Gmelin (MERCURY). See Gmelin-Smithson. Snelling (EMETINE). An orange-red color, changing to violet, forms on pouring a few drops HC1 upon a little KC1O 3 and adding a drop of suspected liquid. Snow (COLCHICINE). Shake out with a mixture of 18 Cc. chlo- roform, 2 Cc. alcohol, 80 Cc. of petroleum ether, and 10 to 15 drops NH 3 . Soldaini (GLUCOSE). Dissolve 15 Gm. cupric carbonate in 1,400 Gm. water with the aid of 416 Gm. KHCO 3 . Upon boiling this solution with glucose, cuprous oxide separates out. See Ost's copper reaction. TESTS AND REAGENTS. 285. Sollas (GELATIN IMBEDDING). Transfer the tissue from water to melted gelatin jelly (prepared by melting gelatin after it has absorbed as much water as it can take up), and allow it to remain until well permeated. Then let mass set, and cut section, which should be transferred to a slide as soon as cut, and covered with a drop of glycerin. A cover is then put on and the mouth closed with some suitable cement. The gly- cerin gradually permeates the gelatin mass and converts it into glycerin jelly, the change being hastened by placing the slide in an oven kept at 20 to 30 C. Sollman (SUGAR). Modified Fehling's solut., in which copper salt is replaced by a cobalt or nickel salt. With a nickel salt, the apple-green solut. gives a canary-yellow color change; with cobalt, the bluish-green solut. becomes reddish-brown. An excess of metal does not hinder reactions, as the latter occur only on boiling. Soltsiens (SESAME OIL). Melt 2 to 3 parts of fat to be exam- ined in a test-tube on a boiling water-bath, add a solut. stan- nous chloride in HC1 (i : 19) i part, shake well, and replace on the water-bath. Presence of sesame oil is shown by a rasp- berry or wine-red color in the stannous-chloride solut. Reac- tion will detect i% sesame oil. Sonnenschein (ALKALOIDS), i. Suspend cerous hydroxide in KOH solut. and pass Cl gas through the mixture until forma- tion of brownish-yellow eerie hydroxide is complete. Collect, wash, and dry the hydroxide, and add a trace to a solut. of the alkaloid in H 2 SO 4 . For particulars of color reactions see Hager, "Pharm. Praxis," 1886, I, 207. 2. Ppt. a solut. of am- monium molybdate in HNO 3 with H 3 PO 4 , wash ppt., boil with nitro-hydrochloric acid to drive off NH 3 , evaporate to dry- ness, and dissolve residue in io-% HNO 3 . Weak acid solut. of alkaloidal salts give yellow ppts. with this reagent, as do also NH 3 and some other bases. Compare Jungmann's reaction. Sonnenschein (BLOOD). On extracting blood stains with dis- tilled water and pptng. with sodium-tungstate solut. strongly acidified with acetic acid, a reddish-green fluorescence appears, on adding NH 3 . 286 TESTS AND REAGENTS. Sonnenschein (PROTEIN). A ppt. forms on adding a sat. solut. sodium tungstate, strongly acidulated with acetic or phos- phoric acid. Sonstadt (CALCIUM). Sodium tungstate gives a ppt. with calcium salts. Souchere (PEANUT OIL). Separate the free fatty acids from the suspected oil and dissolve them in boiling alcohol. In the presence of peanut oil arachic acid separates out in form of characteristic pearly crystals on cooling. Soulier (MACERATING MIXTURES). Solut. of ammonium or potassium sulphocyanide containing 10, 5, 2.5, or 1.25 per cent, are mixed with Ripart-Petit preservative fluid, in the proportions of 20 Cc. to 20 Cc., 30 Cc. to 10 Cc., 35 Cc. to 5 Cc., 36 Cc. to 4 Cc., 37 Cc. to 3 Cc., 38 Cc. to 2 Cc., 39 Cc. to i Cc., or 39.5 Cc. to 0.5 Cc., the best results being obtained with the 2.5 per cent, sulphocyanide solut. Or the Ripart-Petit fluid is mixed with Kroneker's artificial serum, or with pepsin, javelle water, io-% sodium- sulphate solut., or 1.5-% NaOH solut. Solutions of NaCl, KOH, or NaOH may also be mixed with any of the usual fixing agents. Source (URIC ACID). See Magnier de la Source. Southey (OPIUM). A blue color appears on adding sulpho- molybdic acid. Souza, De- (PYRIDINE FOR HARDENING). Pyridine is recom- mended for hardening, dehydrating, and clearing tissues at the same time. They may be stained after hardening by means of aniline dyes dissolved in the pyridine, or passed through water and stained by the usual processes. It is said to harden quickly, and to give particularly good results with brain. Soxhlet (MARGARINE IN FATS), i Gm. phenolphtalein added to 100 kilos of fat, will afford a red color if margarine present. Spasski (BENZALDEHYDE IN BITTER-ALMOND WATER). A bitter-almond water made from benzaldehyde and hydrocy- anic acid may be recognized by its chlorine content (commer- cial benzaldehyde is prepared from benzyl chloride, traces of which adhere even to the purified benzaldehyde). The chlorine may be dectected in the fused mass obtained by mix- ing 20 Cc. suspected liquid with 40 to 50 Cc. H 2 O 2 and 6 to 7 chlorophyll gives a deep-blue solut. and a residue soluble in ether with brown color. If copper present, residue dissolves in alcohol with green color. 2. Add HC1 to alcoholic extract if green color develops, copper is present. Tschugaeff (CHOLESTERIN). On dissolving cholesterin in glacial acetic acid, adding an excess acetyl chloride, and then a small fragment ZnCl 2 , and finally warming for 5 minutes, the fluid acquires a red or pink color with a greenish-yellow fluores- cence. Coloration still visible in a i : 80,000 solut. cholesterin. Tuchen (ETHEREAL OILS). Many ethereal oils fulminate when 4 to 6 drops of the oil are brought into contact with o.i Gm. iodine. Tucholka (BISABOL MYRRH). Mix 6 drops of a i : 15 ethereal ex- tract of sample with 3 Cc. glacial acetic acid in a test-tube, and overlay on 3 Cc. cone. H 2 SO 4 . At contact-line a pink zone devel- 3o6 TESTS AND REAGENTS. ops immediately, gradually spreading to the acetic-acid layer, and remaining some time. Herabol myrrh gives only a very slight pink color, the zone being first green, then changing to brown with green fluorescence after standing some time. Tullberg (NARCOTIZATION METHOD). For actinias, slowly add to the water containing the expanded animal a 33-% solut. MgCl 2 , until the vessel contains i% salt, i.e., add 33 Cc. solu- tion for each liter sea- water. The operation should be finished within half an hour, and the animal may be fixed half an hour later. For terrestrial and fresh- water invertebrates, use rather stronger solutions. Turner (BORAX). Borax gives a green color on being heated in the blowpipe flame with a mixture of 9 parts potassium bisul- phate and i part fluorspar. Tyson (HETERO-ALBUMOSE IN URINE). Acidulate a little urine with acetic acid, mix with one-sixth its volume sat. solut. NaCl, then boil and filter. Albumin and globulin are pptd.; if the filtrate on cooling gives a ppt. on adding more brine, then albumose is present. Udransky (BILIARY ACIDS). Mix i Cc. aqueous or alcoholic solut. with i drop o.i-% aqueous furfurol solut., and overlay on i Cc. cone. H 2 SO 4 if biliary acids present a violet-red zone forms. Udransky (TYROSIN). To i Cc. of dissolved substance add i drop 0.5-% solut. furfurol, and overlay on i Cc. cone. H 2 SO 4 a pink zone forms. Udransky (UREA). To cone, solut. of substance add benzoyl chloride and an excess of NaOH benzoyl-urea forms and ppts. Udransky-Baumann (GLYCERIN AND CARBOHYDRATES). Tests depends upon Baumann's reaction with benzoyl chloride and NaOH. Diamines also give this reaction, hence the presence of the first-mentioned compounds must be confirmed by means of the furfurol reaction. See Molisch's reaction. Uffelmann (FREE HYDROCHLORIC ACID IN GASTRIC JUICE). Test-paper prepared from an amy lie- alcohol extract of huckle- berries is changed in color from a grayish-blue to a pink by HC1 in gastric juice. Uffelmann (FREE ACIDS IN GASTRIC JUICE), i. i drop solut. Fe 2 Cl 6 , 0.4 Gm. alcohol, and 100 Gm. water. 2. 3 drops TESTS AND REAGENTS. 37 solut. Fe 2 Cl 6 , 3 drops cone, solut. carbolic acid, and 20 Cc. water. HC1 decolorizes this reagent, lactic acid colors it yellow, and butyric acid causes a milky turbidity. Uffelmann (LACTIC ACID). Phenol solut., colored by ferric chloride, is colored yellow by lactic acid. Butyric acid gives a similar reaction. Uffelmann (NITRIC ACID). On adding 3 or 4 drops of liquid to be tested to 1.5 Cc. H 2 SO 4 colored pale-pink by a small frag- ment diphenylamine, a blue color develops. Ultzmann (BILIARY PIGMENTS). Shake 10 Cc. urine with 3 to 4 Cc. KOH solut. (1:3) and treat with excess pure HC1 if biliary pigments present, the mixture acquires a beautiful emerald-green color. Ultzmann- Hoffmann (BILIFUSCIN). See Hoffmann-Ultzmann. Umikoff (WOMAN'S MILK). Mix 5 Cc. milk with 2.5 Cc. io-% NH 3 , and heat 15 or 20 minutes on water-bath at 60 C. If milk is that of a woman it acquires a violet-red color, the more intense the longer the period since the beginning of lactation. The milk of cows or other graminivorous animals, under simi- lar treatment, acquires a yellowish or at most yellowish-brown color. Underwood (GOLD STAINING PROCESS). Wash sections of decal- cified teeth in NaHCO 3 solut., then treat for half to one hour with i-% neutral solut. gold chloride, wash in water, and re- duce in i-% formic acid, kept fairly hot on a water-bath in the dark. They will turn crimson in about an hour, arid should then be washed for half an hour in cold water and mounted in glycerin jelly. Unna (BLEACHING CHROMIC OBJECTS). The brownish-green color is removed by treating with H 2 O 2 . Unna (HEMATOXYLIN STAIN). "Over-ripening" of hematoxy- lin stains, brought about by excessive oxidation, is prevented by adding a reducing agent, like sulphur. Dissolve i part hematoxylin in 100 parts alcohol, and add to a solut. of 10 parts alum in 200 parts water. In 2 or 3 days, when the solut- has become somewhat strongly blue, add 2 parts sublimed sul- phur. This fixes the stage of oxidation attained by the solut., and the latter may be used at once for staining. It does not give so energetic a stain as a solut. totally and instantaneously 308 TESTS AND REAGENTS. ripened with H 2 O 2 , and does not keep so well as a solut. con- taining glycerin. See Mayer's glychemalum. Unna (LEPRA-BACILLUS DOUBLE STAIN: DRY METHOD). Stain in aniline-water fuchsine 12 to 24 hours. Differentiate in 10- to 20-% aqueous solut. HNO 3 till section is yellowish, then place in dil. alcohol several seconds till red color returns, wash out acid with prolonged rinsing in dist. water or by dipping once in weak NH 3 . Remove excess of water from object-glass with blotting-paper or by careful heating over flame i or 2 minutes till section absolutely dry, and immediately mount in chloroform balsam. Unna (STAIN FOR SMOOTH MUSCLE). Stain sections for 10 min- utes in polychromatic methylene-blue solut., rinse in water, and place for 10 minutes in i-% solut. potassium ferricyanide, which fixes the color. Next differentiate with alcohol con- taining i% HC1, and after the collagen ground comes out white (about 10 minutes), pass the sections into absolute alcohol prior to clearing and mounting in balsam. Unverdorben-Franchimont (RESINS AND TERPENES). Reagent is a cone, aqueous solut. copper acetate. Sections of tissue ex- posed for several days to the action of the solut. have their resinous portions colored emerald green. Upson (GOLD AND IRON METHOD). Material hardened in the dark in potassium-bichromate solut. (i-%, gradually in- creased to 2- or 2.5-%) for 4 to 6 months is washed with water, treated for 2 or 3 days with 50-% alcohol, which is changed as often as necessary, and then left in 95-% until they show a decidedly green color (2 to 4 weeks), the alcohol being changed as often as precipitates occur. Cut sections under water or by the celloidin process, and in the former case place them in alcohol immediately and leave them there for 2 to 3 days. Next immerse for i to 2 hours in a i-% solut. gold chloride acidulated with 2-% HC1, rinse in water, and treat for half a minute with a solut. of about 0.2 Gm. potassium ferrocyanide in 5 Cc. io-% solut. KOH. Then wash for half a minute more in simple KOH solut., and afterward for some time in distilled water. The reducing solution is freshly prepared when re- quired by mixing 5 Cc. sulphurous acid and 10 to 15 drops 3-% tincture iodine, and adding i drop solut. Pe 2 Cl 6 . A section is TESTS AND REAGENTS. 39 placed on a piece filter-paper in a watch-glass, the reducing mixture quickly poured over it, and as soon as a rose-red color appears the section is removed into distilled water. After changing the water once, place the section on a slide and immerse in absolute alcohol for 5 to 15 minutes, then clear with clove oil and mount in balsam. As the treatment with potas- sium ferrocyanide may cause the formation of Prussian-blue in the tissue subsequently, it is sometimes omitted. The sections must be kept in the dark. Upson (GOLD AND VANADIUM METHOD). Sections prepared as for Upson 's gold and iron method are placed for 2 hours in a mixture of 5 Cc. of i-% gold-chloride solut., 10 drops sat. solut. ammonium vanadate, and 3 drops HC1. Then wash with dist. water, and place for half a minute or so in a mixture of 5 Cc. io-% KOH solut., 10 drops io-% potassium-per- manganate solut., and a trace ammonium vanadate. Next rinse in dist. water, and treat until they become red with the reducing fluid. This is prepared by mixing 15 drops 3-% tincture iodine to which tin chloride has been added until it becomes white or yellowish, 3 Cc. dist. water, and 3 to 5 drops sat. aqueous solut. iron phosphate. At the moment of using add 3 Cc. sulphurous acid, pour the mixture over the section as in Upson 's gold and iron method, and finish in accordance with that method. Uschinsky (CULTURE SOLUTION FOR BACTERIA). Glycerin, 30 to 40 Gm.; NaCl, 5 to 7 Gm.; CaCl 2 , o.i Gm.; MgSO 4 , 0.2 to 0.4 Gm.; potassium phosphate, 2 to 2.5 Gm.; ammonium lactate, 6 to 7 Gm.; sodium asparaginate, 3 to 4 Gm. Uslar-Erdmann (ALKALOIDS). See Erdmann-Uslar. Valenta (FATS). Intimately mix equal volumes fat and glacial acetic acid (sp. gr. 1.0562) in a test-tube, and if no solution takes place, heat. Three classes of oils are distinguished, according as solution results at ordinary temperatures, at temperatures up to the boiling-point of glacial acetic acid, or whether even then, solution is incomplete. With oils dissolv- ing on heating, the temperature is observed at which, upon cooling, turbidity first appears. According to Bach, the same observations made with David's alcoholic acetic acid (q.v.) and the free fatty acids separated from the fats, give good results. 3io TESTS AND REAGENTS. Valentin (FUCHSINE TEST). Upon shaking ether with a solut. containing fuchsine, the latter is not dissolved by the ether; upon adding ferrous iodide, however, the ether is colored violet. Valzer (ALKALOIDS). Modification of Mayer's test. KI, 49.8 Gm. ; water, i liter. Shake solut, with excess of HgI 2 and filter. Van Beneden (SUBLIMATE SOLUTION). Sat. solut. of HgCl 2 in 2 5~% acetic acid. Van Beneden- Neyt (ACETIC ALCOHOL). Equal volumes glacial acetic acid and absolute alcohol. Van Deen (BLOOD). A blue color results on adding to a highly dil. solut. containing blood a few drops freshly prepared tinc- ture guaiac and a little ozonized turpentine oil. Van de Vyvere-Franqui (GLUCOSE). See Franqui-Van de Vyvere. Van der Velden (HYDROCHLORIC ACID IN GASTRIC JUICE). See Maly's test; also Schuchard's test. Van Ermengen (STAINING FLAGELLA). Treat cover-glass prep- arations for 5 to 30 minutes with a mordant composed of i part 2-% solut. osmic acid, 2 parts 10- to 25-% tannin solut., and 4 or 5 drops acetic acid to every 100 Cc. mixture. Then wash in water and alcohol, place in a solut. of AgNO 3 , and trans- fer for a few seconds to a solut. of gallic acid, 5 Gm. ; tannin, 3 Gm. ; sodium acetate, 10 Gm. ; and dist. water, 330 Gm. After again placing in the AgNO 3 solution, wash, and mount in balsam. Van Ermengen (STAINING CILIA OF BACTERIA). See Ermen- gen , Van-. Van Gieson (FORMALDEHYDE FOR HARDENING BRAIN). Solu- tions of formaldehyde, of 4-, 6-, and io-% are used and followed by 95-% alcohol. Van Heurck (MOUNTING MEDIUM). This is naphtalin mono bromide, which has a refractive index of 1.658. Van Walsem (PARAFFIN MASS). For imbedding large objects, add to the paraffin 5% yellow wax. Vaudin (MILK). Introduce 5 drops 1:1,000 solut. indigo-car- mine into a loo-Cc. flask, fill with milk, seal with a cork dipped in paraffin, and set aside. Fresh milk will not discharge the TESTS AND REAGENTS. 3" color for many hours; stale milk becomes discolored in pro- portion to the time it has been kept. Vaughan-Novy (TYROTOXICON). Place 2 or 3 drops each of H 2 SO 4 and phenol on a porcelain surface, and add a few drops of aqueous solut. of ethereal residue of substance a yellow to orange-red color develops if tyrotoxicon present. Test is only a preliminary one, and should always be followed by the physiologic test. Velden (HYDROCHLORIC ACID IN GASTRIC JUICE). See Such- ard's reagent. Ventre-Pacha (SUGAR). To 10 Cc. of the saccharine liquid, fil- tered and clarified if necessary, add 12 drops of pure H 2 SO 4 , then 5 drops solut. of equal parts of nitrobenzene and alcohol, and finally 20 drops of a sat. solut. ammonium molybdate. Then boil for three minutes, when there develops a blue color, which is the more intense the greater the quantity of sugar present. This color is compared with that afforded by a sugar solution of known strength. This test is stated to afford a very intense color with a i : 1,000 sugar solut. ; the best results are obtained with solutions of i : 10,000. An appreciable reac- tion is also obtained with a i: 100,000 solut., and even with one as dilute as i : 1,000,000. Verven (ALKALOIDS). See Marmes reagent. Verworn (NARCOTIZATION). On placing Cristatella for a few minutes in io-% solut. chloral hydrate, they are killed and sooner or later become extended. Vetere, Di- (CASTOR-OIL). See Di-Vetere. Viallanes (CELLOIDIN IMBEDDING). Celloidin is hardened by immersing imbedded mass in chloroform for a few hours. Viallanes (GOLD METHOD). Tissues are treated with i-% osmic acid until they begin to turn brown, then with 25-% formic acid for 10 minutes. Next place in gold-chloride solut. (i: 5,000 or weaker) for 24 hours, in the dark, and afterward reduce in the light with 25-% formic acid. Vidan (SUGAR). A pink color develops on heating to boiling point equal volumes sesame oil and HC1, and adding suspected liquid. Vignal-Ranvier (OSMIUM MIXTURE). Fixing solution is a mix- ture of equal volumes i-% osmic acid and 90-% alcohol. 312 TESTS AND REAGENTS. Objects are afterward washed out in 8o-% alcohol, then washed with water, and stained for 48 hours in picro-carmine or hematoxylin. This method has been applied by Viallanes to the histology of insects. Vignal-Ranvier (PICRO-CARMINE). See Ranvier. Villa vecchia-Fabri (SESAME OIL). This modified Baudouin's test is prepared by dissolving 2 Gm. furfurol in 100 Cc. alcohol. On shaking 10 Cc. suspected oil for half a minute with o.i Cc. furfurol solut. and 10 Cc. HC1 (sp. gr. 1.19) a red color develops if sesame oil present. Ville (CARMINE INJECTION MASS). Mass is prepared exactly like Ranvier 1 s, except that it is more carefully neutralized, dichroic litmus paper being employed as an indicator. Villiers-Fayolle (ALDEHYDES AND KETONES). Reagent is pre- pared by adding just enough H 2 SO 3 to a solut. of magenta to decolorize it on long standing. Villiers-Fayolle (HYDROBROMIC ACID). Add to liquid (free from HNO 3 ) an excess of Fe 2 Cl 6 solut. free from free chlorine. Iodine, if present, separates out and crystallizes, and is vola- tilized on evaporating mixture to dryness and further heating on water-bath. HBr remains unaffected. Add a little water to residue, ppt. Fe with an alkali, add excess of HC1 to filtrate, then add chlorine water drop by drop, shaking the liquid with CS 2 latter is immediately colored yellow by liberated Br. Villiers-Fayolle (HYDROCHLORIC ACID AND CHLORINE). Even traces of chlorine in acid aniline solution (400 Cc. sat. aqueous aniline solut., and 100 Cc. glacial acetic acid) yield brownish to black ppts.; aniline solut. containing ortho-toluidine (looCc. sat. aqueous aniline solut., 200 Cc. sat. aqueous ortho-toluidine solut., and 30 Cc. glacial acetic acid), yield a blue color, changed to reddish- violet on applying heat or cold. Br and I give no color reactions with above mixtures, although Br yields a white ppt. To apply this test to the halogen hy- dracids, the halogens are liberated from their combinations by heating with dil. H 2 SO 4 and KMnO 4 . Villiers-Fayolle (SUGARS, ALDEHYDES, AND KETONES). Re- agent is a solut. rosaniline decolorized by sulphurous acid. The solut. again becomes red on adding aldehydes, grape sugar, invert sugar, galactose, and reducing dextrins, but remains TESTS AND REAGENTS. 3*3 colorless with ketones, levulin, and sorbin. Cane sugar mal- tose and lactose give at first no color, but in a few days the red color develops and increases in intensity. Vincent (DIFFERENTIATING ALPHA-NAPHTOL FROM BETA-NAPH- TOL). lodic acid gives with alpha-naphtol a flocculent, whitish-yellow ppt., rapidly becoming violet; with beta- naphtol the ppt. gradually becomes red, and after a time the liquid has a reddish color, while the ppt. is reddish-brown. Violette (GLUCOSE). Identical with Fehling's solution (q. v.). Virchow (CHROMIC OBJECTS). Ppt. formed on the surface of preparations treated with chromic acid or a chromate and placed in alcohol for hardening or preservation, is entirely pre- vented by keeping preparations in the dark. The alcohol should be changed as it becomes yellow. Vital! (ALKALOIDS). Color reactions are afforded: i. On evaporating to dryness with fuming HNO 3 , and adding i drop alcoholic KOH solut. 2. On treating with H 2 SO 4 , with or without KC1O 3 , and adding an alkaline sulphide. A tr opine causes a violet color, changing to a fine red, when treated by the first method. Morphine dissolved in H 2 SO 4 , and treated cautiously after adding 2 drops of Na 2 S solut. produces a flesh color, changing to violet and then to dark-green. Vitali (BILIARY PIGMENTS). A violet color develops on adding to the urine a solut. quinine bisulphate, neutralizing with NH 3 , taking up with H 2 SO 4 , and adding a crystal of sugar with a little alcohol. See Gmelin's reaction. Vitali (BLOOD). Extract suspected stain with KOH solut., acidulate solut. with acetic acid, and add tincture guaiac. If no blue color appears within 2 hours, addition of turpentine or eucalyptus oil will immediately develop color if blood present. Vitali (CHLORATES). If a drop of aqueous aniline-sulphate solut. be mixed with a few drops cone. H 2 SO 4 and added to a solut. of a chlorate, a deep-blue color results, intensified on diluting with a few drops water. Reaction is not given by nitrates. Vitali (CHLOROFORM). Pass a current of hydrogen through water and ignite as it escapes through a jet tipped with plati- num, i. The colorless flame becomes blue or green when a fine copper wire is introduced into it, if a liquid containing 3U TESTS AND REAGENTS. chloroform or any other volatile chlorine compound be poured into the water. 2 . A red color is produced on passing the gas as above into a mixture of thymol and KOH solut. Vital! (DIFFERENTIATING ATROPINE FROM STRYCHNINE), i. Air opine oxidized with HNO 3 (particularly immediately after evaporating the acid) develops a pleasant odor (like haw- thorn); strychnine does not. 2. Strychnine turns yellow during oxidation, and, after HNO 3 is evaporated, residue also is yellow; atr opine gives no yellow color or yellow residue. 3. Add alcoholic KOH, and evaporate alcohol air opine gives a violet residue, becoming deeper on adding more KOH; strychnine gives a yellow or reddish-yellow residue, becoming reddish- violet on adding KOH. 4. Add water after adding alcoholic KOH with atropine the color will disappear; with strychnine it becomes yellow. 5. Oxidize atropine with HNO 3 , evaporate acid, and treat residue with NH 3 little drops appear which give a violet color with alcoholic KOH; with strychnine the NH 3 gives a reddish-orange color, and the KOH a violet one. Vital! (DIFFERENTIATING CHLORINE, BROMINE, AND IODINE DERIVATIVES), i. On adding a few drops solut. of a bro- mine salt to a solut. of manganous sulphate acidulated with H 2 SO 4 , a violet color develops (chlorine and iodine give none). 2. Hydroxylamine sulphate reduces iodides in the cold, and bromides with heat, but chlorides not at all, hot or cold. 3. Phenylhydrazine sulphate acts like hydroxylamine sulphate, but the liberated iodine acts on the phenylhydrazine and forms a red ppt. KBr affords a reddish-brown ppt. on heating. Chlorides give no ppt. hot or cold. 4. Hypophosphorous acid reduces iodides in the cold, bromides on warming, and chlorides not at all, hot or cold. Vital! (FUSEL OIL). Red to green colors are produced on over- laying a liquid containing fusel oil on H 2 SO 4 . Vital! (MARTIUS' YELLOW [NAPHTOL-YELLOW; BUTTER-YELLOW] IN URINE), i. Evaporate ethereal extract of suspected liq- uid; the residue is colored red upon treatment with KCN solu- tion if Martius' yellow present. If the ethereal solution is shaken with KOH solut., and the latter then acidulated, woollen fibers mordanted with alum will be tinged yellow when TESTS AND REAGENTS. 3 J 5 dipped into the acidulated solution, even when only o.oooooi Gm. naphtol-yellow present. 2. A solut. of naphtol-yellow (even in urine) gives a green lake with cobalt chloride and KOH. 3. The same solution, with SnCl 2 and subsequently with NH 3 yields a white ppt., which becomes rose-red on add- ing more NH 3 . Vital! (QUININE IN URINE). Make alkaline a fairly large quan- tity of urine, and shake out with ether. Add a few drops HC1 to ethereal extract, and evaporate, dissolve residue in water, treat solution once more with NH 3 and ether, and, after evap- orating latter, dissolve residue in an acid, and add chlorine water and NH 3 an intense emerald-green color develops. Vital! (THYMOL). A red color develops on distilling and pass- ing the vapors into a mixture of chloroform and KOH solut. Vital!- Arnold (ALKALOIDS). See Arnold-Vitali. Vitali-Stroppa (CONIINE). i. Add a few drops of a 1:200 solut. potassium permanganate in cone. H 2 SO 4 to coniine or one of its salts, and stir with a glass rod the green color of the solut. changes to violet. 2. Carefully evaporate minute quantity of coniine with a few drops cone. HNO 3 a dark- yellow residue remains, and which, treated with a few drops KOH solut. yields a reddish-brown oil of characteristic hem- lock odor. The oil, evaporated to dryness, gives a brownish- black residue, yielding with cone. H 2 SO 4 an almost colorless solut., changed to yellow by water and excess of NH 3 . Vogel (ALCOHOL). A blue color develops on shaking chloroform containing alcohol with KOH, and applying to a piece of moist- ened red litmus paper. Vogel (CARBON BISULPHIDE). A lemon-yellow ppt. forms on adding to a liquid containing carbon disulphide an alcoholic solut. KOH, followed by a solut. CuSO 4 . Vogel (CHENOPODIUM SEED IN FLOUR). Chenopodium seed is indicated by a rose-red color on digesting the flour for a few hours with alcoholic HC1. Vogel (FERRIC SALTS). A violet color is produced with salicylic acid in slightly acid solut. Vogel (FLOUR). Mixture of alcohol (70-%), 95, and HC1, 5. Heat a small sample of the flour to boiling in the test-tube with the reagent after shaking, and allow to subside. If the flour be 3l6 TESTS AND REAGENTS. pure, the fluid is colorless; gruffs, with bran, are indicated by a straw-colored tint. Corn-cockle flour is betrayed by an orange-yellow ; vetches by a pink ; ergot by a flesh color ; buck- wheat by a green color. Vogel (GLUCOSE). A modified Mulder's test (q. v.), in which litmus is used instead of indigo. Vogel (NARCEINE). A blood-red color develops on adding chlorine water and a few drops NH 3 , and does not disappear on adding excess of NH 3 . Vogel (NITRIC ACID). Nitric acid in water is indicated by a red- violet color on boiling 15 Cc. water with a little gold leaf and a few drops pure HC1, then filtering and adding SnCl 2 . Vogel (QUININE), i. A pink or red color develops on treating with chlorine water and adding potassium ferrocyanide in fine powder. 2. If potassium ferrocyanide and bromine water be added to a quinine solution until a faint yellow tint results and dil. NH 3 be then added, a red color develops. Blaise states that the potassium ferrocyanide is not essential to this reac- tion, tending only to render the color more permanent. If strong NH 3 be added to the red solut., the color changes to green. If half-saturated bromine water be added to 0.25-% solut. quinine until the commencement of a yellow reaction, and if i- to 2-% NH 3 be dropped in after half a minute, a red color is obtained which changes to green on adding cone. NH 3 . Vogel (SULPHURIC ACID). Chlorine is evolved on adding KC10 3 to vinegar containing H 2 SO 4 . Vogel (TANNIN). Chlorine water and a few drops NH 3 cause a blood-red color. Vogel (TURPENTINE OIL). The color of an essential oil contain- ing turpentine is altered on mixing 5 drops with i drop of H 2 S0 4 . Vohl (SULPHUR). A black color develops on heating substance with the clear liquid decanted from a mixture of glycerin and water (2 : i), saturated with slaked lime and freshly-prepared lead hydroxide. Volhard (SILVER CHLORIDES, IODIDES, BROMIDES). This method of determination requires four solutions. i. Decinormal ammonic thiocyanate, made by dissolving about 8 Gm. ammo- nium thiocyanate per liter, and adjusting to decinormal TESTS AND REAGENTS. 3*7 strength with decinormal silver nitrate. 2. Decinormal sil- ver solut. 3. Sat. solut. of iron alum. 4. Pure nitric acid. To standardize the thiocyanate solution, place 50 Cc. deci- normal silver solut. in a flask, add 5 Cc. ferric indicator, and 10 Cc. nitric acid. The thiocyanate is then run in until a faint brown color develops; this should require 50 Cc. To determine chlorides, the difference between the amounts of silver and thiocyanate solutions added indicates the silver used up by the salts. Vom Rath (PiCRO-OsMic ACID). 200 Cc. sat. aqueous solut. picric acid, 12 Cc. 2-% osmic acid solut., and 2 Cc. glacial acetic acid. Vom Rath (PICRO-PLATINIC MIXTURE). 200 Cc. sat. aqueous solut. picric acid, i Gm. platinic chloride dissolved in 10 Cc. water, and 2 Cc. glacial acetic acid. Vom Rath (PiCRO-PLATiN-OsMic MIXTURE). Add 25 Cc. 2-% osmic-acid solut. to the picro-platinic mixture. Vom Rath (PICRO-SUBLIMATE MIXTURE), i part cold sat. solut. picric acid, i part hot sat. sublimate solut., and 0.5 to i% glacial acetic acid. Objects are fixed in this for several hours and then brought direct into alcohol. Vom Rath (PicRO-SuBLiMATE-OsMic MIXTURE). Add 10% of 2-% osmic-acid solut. to the picro-sublimate mixture. Von Duyck (INDICATOR). Perezol; Pipitzahoic Acid. Gives with alkalies a pink to mauve rose, rendered colorless by acids. Von Ebner (DECALCIFICATION MIXTURES), i. Mix 100 Cc. cold sat. aqueous solut. NaCl, 100 Cc. water, and 4 Cc. HC1. Prep- arations are placed in this, and i or 2 Cc. HC1 added daily until they are soft. 2. Mix 2.5 parts HC1, 500 alcohol, 100 water, and 2.5 NaCl. Von Koch (COPAL IMBEDDING METHOD). This is a valuable method for the study of corals and other objects in which hard and soft parts are intimately combined. Small pieces of tissue are stained in bulk and dehydrated with alcohol, then im- mersed in a thin solut. of copal in chloroform, prepared by triturating small fragments of copal with fine sand, adding chloroform, and subsequently filtering. The capsule containing the objects and the copal solut. is gently heated on a tile by means of a night-light placed beneath it, and as soon as the 31 8 TESTS AND REAGENTS. solut. is so far concentrated as to draw out into brittle threads on cooling, the objects are removed from the capsule and left to dry for a few days on the tile. When they have attained such a degree of hardness that they cannot be indented by a finger-nail, sections are cut from them by means of a fine saw. These are then rubbed down even and smooth on one side with a hone, and cemented with the smooth sides downward on slides, Canada balsam or copal solut. being employed for the purpose. Leave the slides for a few days on the warmed tile, and, as soon as the cement is perfectly hard, rub down the sections on a grindstone, then on a hone, to the requisite thin- ness, and polish. Finally, wash with water and mount in balsam. A variation of this plan is to imbed the objects un- stained, remove the copal from the sections by soaking in chloroform, decalcify if necessary, and then stain. Or, after removing the copal, a section may be cemented to a slide by means of hard Canada balsam, the exposed half of the speci- men being then cautiously decalcified and stained. Von March! (NERVE STAIN). Harden the nerves for a week in Muller's solut., then place for a few days in a mixture of 2 parts Muller's solut. and i part of i-% osmic-acid solut. This method gives positive images of the degenerated elements, whereas that of Weigert gives negative ones only. Von Mtiller (INDICATOR), i. Tropaeolin OO. Gives with alkalies a yellow color ; with acids a yellowish-red to red. 2. Tropaeolin OOO No. 2. Gives with alkalies a red color, and with acids a yellow. Von Wistinghausen (BLFING SECTIONS). For neutralizing or bluing hematoxylin-stained tissues, add 3 to 5 drops sat. solut. NaHCO 3 in 70-% alcohol to a watch-glass filled with 70-% alcohol, in which the tissues are soaking. See Squire's method. Vortmann (HYDROCYANIC ACID). Add first a few drops solut. potassium nitrite, then 2 to 4 drops solut. Fe 2 Cl 6 , then dil. H 2 SO 4 until light-yellow color, heat to boiling, allow to cool, add NH 3 , filter, and to filtrate add ammonium sulphide a bluish-green to violet-red color develops if HCN present. Vosseler (VENICE-TURPENTINE MOUNTING MEDIUM). Mix commercial Venice turpentine with an equal volume of 96-% TESTS AND REAGENTS. 3 X 9 alcohol in a tall cylinder glass, allow to stand in a warm place 3 or 4 weeks, and then decant. Microscopic preparations may be mounted in this medium without previous clearing with essentials oils, etc., and as its refractive index is below that of Canada balsam or dammer, delicate details are more distinctly brought out. Stains keep well in the medium. See also Suchannek's formula. Vosseler (WAX FEET). To complete dissociation of macerated tissue the plan is sometimes adopted of placing the tissue on a slide, covering it with a thin glass-cover supported on four little feet made of pellets of soft wax, and tapping the cover with a needle so as to press it down gradually and segregate the cells of the tissue by the repeated shocks. When the seg- regation has proceeded far enough, mounting medium is added and the mount closed. Vosseler obtained a good material for making the wax feet by melting white wax and stirring into it one-half to two-thirds its bulk Venice turpentine. Vreven (DIFFERENTIATING CREOSOTE FROM GUAIACOL). Mix i drop liquid, 2 to 3 drops ether, and i to 2 drops cone. HNO 3 , add 2 drops HC1, and shake in a test-tube. The mixture, especially the ethereal layer, becomes reddish-brown. Let ether evaporate spontaneously if guaiacol present acicular crystals soon deposit; in the case of creosote, only minute oily drops form. Carbolic acid also yields crystals, but these can be readily distinguished from those obtained from guaiacol. Vreven (TROPINE). With a solut. of potassium-cadmium iodide tropine in slightly acid solut. gives a ppt. of well-defined hex- agonal tablets, very soluble in water (hence a cone, slightly acid solution must be employed), and melting at 200 C. With phosphomolybdic acid tropine in slightly acid solut. gives a yellowish ppt. forming crystalline needles. Vrij, De (ALKALOIDS). Reagent is phosphomolybdic acid. See Sonnenschein's reagent. Vrij, De (QUININE). See De Vrij. Vulpius (ACETANILID). Boil a few centigrammes acetanilid with i Cc. potassa lye, and suspend a drop filtered chlorinated-lime solut. on a glass rod over the hot mixture. The drop is soon colored yellow (with a violet tinge by reflected light); upon continued heating it turns violet. 320 TESTS AND REAGENTS. Vulpius (SULFONAL). Upon heating sulfonal with KCN the odor of mercaptan develops. The fused mass yields a red color when treated with Fe 2 Cl 6 (sulphocyanate reaction). Waage (BOMBAY MACE). 3- to 5-% solut. potassium bichro- mate colors secretion of mace reddish-brown. The alcoholic mace extract may either be examined, or microscopical sec- tions may be warmed with reagent and the colorations pro- duced examined. In yellow Bombay mace green bodies are observed as well as brown. Wachhausen (IODINE). Paraldehyde liberates iodine from its combinations with K, Na, and Fe much more completely, al- though more slowly, than other reagents (as Cl, Fe 2 Cl 6 , KMnO 4 , etc.). The I may be recognized by starch paste. Waddington (ARAB IN FOR SERIAL SECTIONS). Prepare a puri- fied gum arabic for serial section mounting by dissolving gum in distilled water, filtering, pouring filtrate into alcohol, and washing the white pasty mass with alcohol until washings are free from water. The white powder obtained on drying dis- solve in distilled water and filter twice. Slides coated with this solut. are drained and dried, and may then be preserved ready for use indefinitely. Wade (BORIC ACID). Boil o.i Gm. substance with 0.5 Cc. HC1 and 10 Cc. methyl alcohol, and continue boiling until liquid evaporated to small volume (in a test-tube), while a moist- ened piece of turmeric paper is held to the mouth of the tube in contact with vapors if boric acid present the characteristic red color develops on paper. Wagner (ALKALOIDS). A solut. of I and KI (decinormal I solut.) throws down brown ppt. with aqueous solut. of alkaloidal salts. Wagner (EOSINE). The color is discharged by collodion. Wagner- Fresenius (SOLUTION). Solut. of I in KI solut. Waldeyer (DECALCIFICATION OF BONE). To o.i-% solut. of palladium chloride add one-tenth its volume HC1. Wallach (SESQUITERPENE). Dissolve ethereal oil to be exam- ined, or a fraction of it, in a large volume glacial acetic acid, and gradually add a little cone. H 2 SO 4 ; a green, then a beauti- ful indigo-blue, color develops, which is considered to indicate presence of a sesquiterpene. Waller- Hue bl (IODINE SOLUTION). See Huebl-W aller . TESTS AND REAGENTS. 3 21 Walz (FIXED OILS IN ESSENTIAL OILS). Color reactions are produced on adding a syrupy solut. SbCl 3 . Wangerin (APOMORPHINE AND MORPHINE). A solut. of 0.3 Gm. each of uranium acetate and sodium acetate in 100 Cc. water gives with a morphine solution a hyacinth-red to orange- yellow reaction, but with apomorphine solutions it gives a brown ppt. which is dissolved by dilute acids, yielding a color- less solut., but which is again thrown down in the colorless liquid on adding an alkali. As the toxins and most other alkaloids do not react like morphine and apomorphine, this test may serve for identifying these two alkaloids. Wanklyn (ALKALINE PERMANGANATE SOLUTION). KOH . 200 Gm., KMnO 4 8 Gm., and dist. water 1,000 Cc. Boil off about 250 Cc., then make up to i liter with ammonia-free water. Wanklyn (AMMONIUM-CHLORIDE SOLUTIONS). For the stronger solut. dissolve 3.15 Gm. NH 4 C1 in 1,000 Cc. dist. water; i Cc. equals o.oi Gm. NH 3 . For the weaker solution mix 10 Cc. stronger solut. with 990 Cc. water; i Cc. equals o.ooi Gm. NH 3 . Wanklyn (STANDARD SOAP SOLUTION). Dissolve 10 Gm. of Castile soap (containing 60% oleic acid) in i liter methylated alcohol (35-%). Standardized against solut. of i.n Gm. pure fused CaCl 2 in i ,000 Cc. dist. water. Wanklyn (STANDARD SILVER-NITRATE SOLUTION). Dissolve 4.79 Gm. AgNO 3 in 1,000 Cc. dist. water; i Cc. equals o.ooi Gm. Cl. Warburg (EHRLICH-BIONDI MIXTURE). Ehrlich-Biondi mix- ture is acidified by diluting 2 Cc. mixture with 40 Cc. dist. water and adding 3 Cc. 0.5-% solut. acid fuchsine and 0.2 Cc. 0.2-% acetic acid. Warington (CITRIC ACID IN LIME AND LEMON JUICE). Ex- actly neutralize 15 to 20 Cc. juice, or 3 or 4 Cc. of cone, juice, with normal NaOH and make up to 50 Cc., then heat to boil- ing and add a slight excess of CaCl 2 solut. The mixture is boiled for 30 minutes, the ppt. collected and washed with hot water, filtrate and washings conc'd to about 15 Cc. and a drop NH 3 added, the ppt. collected on a small filter and washed with boiling water. Both filters with their ppts. are dried, ignited at a low red heat, and the ash titrated with decinormal acid, each Cc. of which equals 0.007 Gm. citric acid. 322 TESTS AND REAGENTS. Warren (GLUCOSE). Like Trommer's test (q. v.). Wartha (ANTHRAQUINONE). A green to bluish-purple develops on heating anthraquinone with KOH and a little alcohol. Wartha (SULPHUR IN ILLUMINATING GAS). A red color develops on adding a drop sodium-nitroprusside solut. to a soda bead that has been passed along the outer part of the gas-flame, then held for a minute in the luminous part of the flame and crushed. Wassilieff-Bogomolow (ALBUMIN AND PEPTONES). See Bogo- molow-Wassilieff. Wasilewsky (BELLADONNA IN MIXTURES). Extract with very dil. HC1, evaporate to syrupy consistency, mix with alcohol, filter, evaporate off the alcohol, shake out with ether, amylic alcohol, benzene, or petroleum ether, make alkaline with NH 3 , and shake out with chloroform. The residue left on evaporat- ing the chloroform may then be purified, and the atropine tests applied. Watson (GALLIC ACID). A red color develops on adding NH 3 and HC1 to an aqueous solut. gallic acid. Watson (PYROGALLIC ACID). A lemon-yellow color develops on adding NH 3 to an aqueous solut. pyrogallic acid. Watson (TANNIN). A purple color develops on adding NH 3 and HNO 3 to an aqueous solut. tannin. Wayne (GLUCOSE). Dissolve 2 Gm. of CuSO 4 , 10 Gm. KOH, and 10 Gm. glycerin in 200 Gm. water. Glucose reduces the diluted solut. upon warming, cuprous oxide separating out. Webb (DEXTRIN FREEZING MASS). A thick solut. dextrin (i : 4 ) in aqueous solut. carbolic acid is used for imbedding, and subsequently frozen. Weber (BLOOD). A blue color results on treating urine, or other liquid containing blood, with glacial acetic acid, shaking out with ether and adding to the separated ethereal layer old resinified turpentine oil, together with a few drops of freshly prepared io-% tincture guaiac. Compare Almen's test. Weber (!NDICAN). Heat to boiling 30 Cc. urine containing indi- can with 30 Cc. HC1, then cool and shake with ether a blue foam will form, whilst the ethereal layer will be colored red. See MacMunn's test. TESTS AND REAGENTS. 3 2 3 Wedl (ORSEILLE OR ORCHELLA STAIN). Mix 5 Cc. acetic acid, 20 Cc. absolute alcohol, and 40 Cc. dist. water, then add suffi- cient archil, from which excess of NH 3 has been driven off, to form a dark-reddish fluid. Weichselbaum (TUBERCLE STAIN). Stain as with Ziehl-Neel- sen, then, after rinsing in water, place directly in a cone, alco- holic solut. methylene blue, where cover-glass is allowed to remain until evenly stained blue;, then rinse in water. Weidel (XANTHINE BODIES). Dissolve in warm Cl water, evap- orate on water-bath, and treat under bell- jar with NH 3 a dark-pink or purple develops, changed to violet by KOH or NaOH. Reaction afforded by xanthine, heteroxanthine, paraxanthine, and carmine. Weigert (AMMONIACAL GENTIAN VIOLET). Stronger ammonia, 0.5 Gm.; gentian violet, 2 Gm.; absolute alcohol, 10 Gm. ; dist. water, 90 Gm. Weigert (BACTERIA STAIN). Treat section with a sat. solut. gentian violet or methylene violet in aniline water. If sec- tion is stained on object-glass, remove excess of stain with blotting-paper, and drop solut. KI on it. In this case allow stain to remain in contact with section only a very short time. The sections stained in a saucer are afterward washed in a solut. NaCl, placed upon the object-glass, dried, and treated with KI. Afterward dry again with blotting-paper and drop on it aniline several times. Then remove the aniline from the now transparent section with xylene and mount in balsam. Weigert (BACTERIA STAINS). Dissolve 2 to 4 Gm. methylene blue (or 2 Gm. fuchsine or 2 Gm. victoria blue) in 15 Cc. alco- hol, and dilute solut. with 85 Cc. water. Weigert (CLEARING CELLOIDIN SECTIONS). A mixture of 3 parts xylene with i part anhydrous carbolic acid is used. As this mixture discolors basic aniline stains, replace the carbolic acid with xylene when they are employed. Weigert (CORRECTING PICRO-CARMINE). Soluts. of unsatisfactory picro-carmine are treated with small quantities acetic acid until a slight ppt. remains, even after stirring; then place on one side for 24 hours, filter, and add NH 3 , drop by drop, at intervals of 24 hours, until solut. becomes clear. If the solut. stains too yellow add acetic acid ; if it overstains red add a little NH 3 . 324 TESTS AND REAGENTS. Weigert (FIBRIN STAINS). Stain sections of alcohol material in a sat. solut. gentian- or methyl violet in aniline water, then place on a slide, remove excess of stain by means of blotting- paper, and pour Lugol's solut. on to them. Next remove excess of lugol with blotting-paper and add a drop aniline to differentiate and clear. Change aniline once or twice as it becomes dark, then remove all traces of it by means of xylene, and mount in balsam. In the modification of this stain used as a neuroglia stain, a warm saturated solut. methyl violet in 70- or 80- % alcohol is decanted after cooling and 5% aqueous solut. (? sat.) oxalic acid added. Moreover, the pure ani- line is replaced by a mixture of equal parts of aniline and xylene. Weigert (GRAM'S METHOD). In this modification aniline is sub- stituted for alcohol in order to avoid prolonged washing with the latter, and the process is conducted on a slide. The sec- tion is placed on a slide stained with a few drops gentian violet aniline- water prepared as in Gram's method, the excess of fluid removed, and a few drops of Gram's solut. applied. Subsequently remove liquid by gently blotting it off, then wash section by allowing aniline to flow backwards and for- wards over it, and when color ceases to come away repeat operation with xylene for about i minute, then mount in balsam. Weigert (HEMATOXYLIN). i. Dissolve i part of hematoxylin in 10 parts absolute alcohol; then add 90 parts dist. water and i part of aqueous solut. (i : 70) lithium carbonate. 2. One Cc. cold sat. solut. lithium carbonate is added to 100 Cc. solut. of 0.75 to i.o Gm. hematoxylin in 10 Gm. alcohol and 90 Gm. water. The washing of the stained sections is done with a borax-potassium ferricyanide solut. (borax, 2; potassium ferricyanide, 2.5; water, 100). Weigert (NEUROGLIA STAIN). Pieces of tissue 0.5 Cm. thick are hardened for 4 days or more in 4-% formaldehyde solut. and then mordanted for 8 days at normal temperature in an aqueous solut. containing 5% neutral copper acetate, 5% acetic acid, and 2.5% chrome alum; prepare solut. by adding the alum to water, raising the solut. to boiling-point, and adding the acid and powdered acetate. Next wash tissues in water, TESTS AND REAGENTS. 325 dehydrate, imbed in celloidin, and cut sections. Treat sec- tions for 10 minutes with a 0.3-% solut. KMnO 4 , wash well in water, then immerse for 2 to 4 hours in a solut. prepared by dis- solving 5 % each of ' ' chromogen ' ' and formic acid in water, filtering, and to each 90 Cc. adding io.Cc. io-% sodium- sulphite solut. After this bath leave sections for 24 hours in a 5-% solut. of chromogen, then carefully wash, and s with a modification of Weigert's fibrin stain, which see. Weigert (STAINING BRAIN TISSUE). Pieces of brain and spinal cord are hardened in bichromate solut., followed by alcohol, then imbedded in celloidin or gum. If imbedded in celloidin, the pieces are subsequently taken from the alcohol and placed for i or 2 days in sat. aqueous solut. copper acetate, diluted with an equal bulk water, the mixture being kept at about 40 C. Afterwards transfer pieces to 80- % alcohol until required for cutting. Or, sections can be cut first, and then treated with copper acetate. To stain sections, after being well washed in 90-% alcohol, they are transferred to Weigert's hematoxylin, and left for a few hours to 2 days, according to differentia- tion required. When opaque and of a deep blue-black color, wash well for 2 or 3 days in distilled water. Next decolorize for 0.5 to 2 hours in a solut. 2 Gm. borax and 2.5 Gm. potas- sium ferricyanide in 200 Cc. of water. As soon as the gray and white substances are sharply defined, again wash sections in water for half an hour, then dehydrate, clear, and mount in balsam. Weigert (STAINING IN ACTINOMYCOSIS). Immerse sections for i hour in WedVs orseille stain, then quickly rinse with alcohol, and counterstain with gentian violet. If it be desired to stain mycelium also, afterwards submit sections to Weigert's modi- fication of Gram's method. Weigert (VARNISH FOR MOUNTING SECTIONS). Mount large sec- tions in photographic negative varnish without cover-glasses. Weigert-Koch (ANILINE-FUCHSINE OR METHYLENE-BLUE). Sat. aniline water, 100 Cc.; cone, alcoholic solut. methylene blue (or fuchsine), n Cc. ; absolute alcohol, 10 Cc. This solut. will keep 10 to 12 days. Weil (CANADA BALSAM FOR IMBEDDING). Heat Canada balsam till it becomes brittle when cold, then dissolve in chloroform. TESTS AND REAGENTS. Objects to be imbedded (bone or teeth) are heated in this on a water-bath. See J. R. M. S., 1888, 1042. Weil-Gilbert (!NDICAN IN URINE). Add i to 2 drops solut. Fe 2 Cl 6 and 2 drops chloroform to 5 Cc. each of HC1 and urine, and shake mixture chloroform becomes colored light- or dark-blue, according to quantity of indican present. Instead of Fe 2 Cl 6 there may be employed ammonium persulphate. Weingaertner (BASIC AND ACID COLOR). Tannin, 25 Gm.; sodium acetate, 25 Gm.; water, 250 Gm. Basic colors are pptd. by the reagent, but not acid colors. Weiske (INDICATOR). Add a few drops Fe 2 Cl 6 solut. to an aqueous solut. salicylic acid, then cautiously add dil. NaOH till exactly neutralized. On adding a few Cc. of this yellowish-red solut. to the acid solut. under examination, and neutralizing with NaOH, a deep violet color appears, but vanishes with the slightest excess of alkali. Weissman (Acio MIXTURE). Solut. for dissolving iron samples consists of 10 vol. cone. HNO 3 , 2 vol. cone. H 2 SO 4 , and 10 vol. water. Ulzer and Brull also recommend the addition of a little cone. HC1 during concentrating. Wellcome (MORPHINE). Chlorinated lime gives with a mor- phine solut. a red color. Weller (TITANIUM). A few drops H 2 O 2 added to a solut. titanic acid in H 2 S0 4 develops an orange-red to yellow color. Welmann (VEGETABLE FATS). Dissolve 5 Gm. sodium phos- phomolybdate in water, treat with cone. HNO 3 , and dilute to 100 Cc. i Cc. or i Gm. fat is dissolved in 5 Cc. chloroform and shaken for a minute with 2 Cc. reagent. If vegetable fats (cocoanut oil excepted) present, a green color forms,, changing to blue upon adding NH 3 . Weltzien (HYDROGEN DIOXIDE). Fe 2 Cl 6 and potassium ferri- cyanide give with H 2 O 2 a blue color. Wemince (OILS). Nitric-oxide gas is passed into a suspension of the oil with water. The nitric oxide is produced from iron turnings and HNO 3 . Non-drying oils are solidified in this test. (Compare Barbot's, Behren's, Boudet's, Cailletefs, and Poutet's tests.) Wender (ALKALOIDS). Reagent is a solut. of furfurol, 5 drops, in cone. H 2 S0 4 , 10 Cc. On stirring alkaloid in a porcelain TESTS AND REAGENTS. 327 capsule with 2 to 3 drops of reagent, using a glass rod, various reactions are given, as follows: A tr opine, Aconitine, Brucine, and Colchicine brown mixture. Strychnine muddy-brown color becoming dark-green on heating, then muddy-blue and violet on adding a few drops water. Morphine and Codeine red-brown, violet-red on heating; with codeine mixture rap- idly deodorizes. Veratrine yellow, then olive-green with blue margins, then sap-green, and finally blue; on heating, violet. Sabadilline and Papaverine like veratrine, but tints are less pure; brownish, then muddy- violet. Digitalin brown, reddish on heating. Quinine dark brownish-green; on heating, green, then brown; on adding water, margins dis- tinctly green. C online and Nicotine brown, indistinct and non-characteristic color. Wender (GLUCOSE). See Neumann-Wender's test. Wender (SUCROL; DULCIN). Treat i or 2 crystals with fuming HNO 3 in a porcelain evaporating-dish a violent reaction takes place, and an orange-yellow substance results. On evaporat- ing to dryness on a water-bath, the residue is varnish-like, orange-yellow, and soluble in alcohol, ether, or chloroform. On adding 2 drops each of carbolic acid and cone. H 2 SO 4 to the residue, and stirring with a glass rod, an intense blood-red color develops. Wender (SUGAR IN URINE). Dilute 5 to 10 Cc. urine with 10 vol- umes water, and to i Cc. of the mixture add i Cc. of a i : 1,000 aqueous solut. methylene blue and i Cc. decinormal KOH, diluted with 2 Cc. water. Boil up several times. If urine con- tains as little as 0.5% sugar, complete decolorization occurs. If blue color persists, urine cannot be regarded as diabetic. Wender- Neumann (GLUCOSE). See Neumann-Wender. Wenzel (ALKALOIDS). These yield various colors with a solut. i Gm. KMnO 4 in 200 Gm. H 2 SO 4 . Veratrine, for instance, yields first a light-red, then an orange ppt. Weppen (MORPHINE). Treatment with sugar, H 2 SO 4 , and Br. affords a red color. Weppen (VERATRINE). If a small quantity veratrine is mixed with about six volumes cane sugar and then a few drops cone. H 2 SO 4 , a yellow color develops, changing to green and finally to blue. Neumann-Wender employ, instead of H 2 S0 4 and cane TESTS AND REAGENTS. sugar, a solut. furfurol in H 2 SO 4 . Morphine and codeine yield with either reagent unstable red colors. Werber (NITRO-GLYCERIN). Extract with ether or chloroform, add 2 drops aniline, evaporate, then add a few drops H 2 SO 4 a purple to dark-green color appears. Werner (AMYLIC ALCOHOL IN CHLOROFORM). On treatment with potassium bichromate and H 2 SO 4 valerianic acid forms. Werner-Schmidt (FAT IN MILK). Add to milk an equal volume HC1 (sp. gr. i.i), heat on water-bath till nearly black, then cool, and extract with ether. On evaporating this the fat remains and may be weighed. Werther (META-VANADATES). An acidulated solut. of a meta- vanadate shaken with H 2 O 2 gives a red color ; if highly diluted a brownish rose-red color results ; when shaken with ether the color remains unchanged and the ether colorless. Weselsky (INDICATOR). Resazurin. Gives a blue color with alkalies, and a red with acids. Also known as Crismer's indicator. Weselsky (PHLOROGLUCIN). Upon adding toluidine nitrate and KNO 3 to a phloroglucin solut., a light-yellow color first de- velops, and gradually becomes opalescent, then orange, and finally cinnabar-red. In extreme dilutions the ppt. remains suspended for a long time ; upon settling, the solution appears orange-red, the ppt. cinnabar-red. By means of this reaction phloroglucin can be detected in solut. of i : 200,000. Weselsky (REAGENT). HNO 3 saturated at a low temperature with nitrous acid. Weselsky (TEST PAPER). Resazurin paper. Paper gives with alkalies a blue, and with acids a red, color. Wetzel (CARBONIC OXIDE IN BLOOD). Three volumes of a i-% tannic-acid solut. are added to the blood after dilution with 4 volumes water. Normal blood is gradually colored gray, but blood containing carbonic oxide remains red. Weyl (CREATININE AND CREATIN). Upon treating urine with a dil. solut. sodium nitroferricyanide and subsequently with soda lye it will acquire a handsome ruby-red color, soon changing to yellow if creatinine is present. Other sulphur compounds interfere with the test. Salkowsky adds acetic acid after the yellow color has appeared, and warms; the solut. becomes TESTS AND REAGENTS. 329 blue, and Prussian blue separates out. Creatin boiled with dilute acid is converted into creatinine, and then answers the test. Jaffe also recommended the same test. Weyl (NITRIC ACID IN URINE), i. Distil 200 Cc. urine with 30 to 40 Cc. HC1 or H 2 SO 4 and receive distillate in KOH. On now adding to latter metaphenylenediamine, a yellow color develops. 2. With pyrogallic acid and H 2 SO 4 distillate gives a yellowish-brown color. 3. Distil as under No. i, treat dis- tillate with dil. H 2 SO 4 , add at once solut. sulphanilic acid, and in 8 to 10 minutes add naphtylamine hydrochlorate a red color develops. Wharton (MINERAL ACIDS IN VINEGAR). Add a little sugar to the vinegar and evaporate to a syrupy consistence, then add KC1O 3 and stir for 2 minutes. If mineral acid is present the chlorate will be decomposed with ignition, chlorine being given off. White (REAGENT). A 1:30 cobalt-nitrate solut. gives various reactions, as follows: Phosphates Violet ppt. soluble in NH 3 and dilute acids. Ar senates and Arsenites Pink ppt. soluble in NH 3 and dil. acids. Hypophosphites No ppt., but if salt contains i part phosphate in 200, a light-blue ppt. forms. Re- action very delicate. Ferrocyanides Green ppt. insoluble in NH 3 and dil. acids. Ferricyanides Red ppt. insoluble in NH 3 and dil. acids. White (SECTIONS OF BONE). Cut or grind down sections of osseous or dental tissue moderately thin and soak in ether for 24 hours. Then place for 2 to 3 days in thin collodion colored with fuchsine, made by dissolving the dye in methylated alco- hol, adding requisite quantity of ether, then the pyroxylin. Subsequently place sections in alcohol to harden the collodion, and afterward grind them down to the requisite thinness be- tween two plates of old ground glass with water and pumice powder. Finally mount, surface-dry, in stiff balsam or storax, taking care to use as little-heat as possible. Whitman (HARDENING METHODS). First treat pelagic fish ova for 5 to 10 minutes with a mixture of equal parts sea water and 0.5-% osmic-acid solut., harden for 2 days in a mixture of equal parts 0.25-% solut. platinum chloride and i-% chromic-acid solut. Before transferring to alcohol prick the membrane. 33 TESTS AND REAGENTS. The ova of amphibia, after being fixed, are left in a io-% solut. sodium hypochlorite diluted with 5 to 6 volumes water until they can be shaken free. Whitney (GLUCOSE IN URINE). The formula for this has not been divulged, but the following solution by S. H. Shieb is prac- tically identical in action, and was repeatedly standardized by adding known quantities of pure grape-sugar to non-dia- betic urine: a. Ammonium sulphate (purest), 1.2 Gm.; copper sulphate (purest), 2.6 Gm. ; distilled water, 50 Cc. b. Caustic potassa (by alcohol), 20 Gm.; distilled water, 50 Cc. Dissolve, and when cool add glycerin, 50 Cc.; ammonia water, sp. gr. 0.960, 300 Cc. Add a to b and dilute the whole to 500 Cc. with distilled water. Stopper securely and shake till thoroughly mixed. As to the method: Heat i fl. dram of this solution in a test- tube to boiling. Add the urine drop by drop, at slow intervals,, boiling after each addition until the blue color has been dis- charged and the fluid has a light amber color or is colorless. 17 minims urine represent i grain sugar per fl. oz. 9 ' ' 2 grains ' ' " ' ' 7 " " " 3 6(( (i < ( < < i< i i 4 s " " " s ' < < < i 6 ' ' ' ' f * ' ' 4 7 " < i < ( (( Q (( (< ' ' ' ' 4 P 3 " " " 9 " " " " 3 " I0 " If the urine contains more than 10 grn. of sugar per ounce, it must be diluted with an equal quantity of water, and the number of grains per fl. ounce multiplied by two. Med. Exam, and Pr act. Wibel (WATER IN BUTTER). Dissolve butter in ether saturated with water and pour solut. into a narrow graduated tube con- taining a measured quantity of salt solut. mixed with some TESTS AND REAGENTS. 33 1 acetic acid and litmus tincture. Mix the two liquids by inclin- ing the tube up and down, and allow to settle, then observe increase in volume of red solut. Wickersheimer (PRESERVATIVE SOLUTION). 100 Gm. alum, 25 Gm. common salt, 12 Gm. saltpeter, 60 Gm. potassium carbon- ate, and 20 Gm. arsenous acid, dissolved in 3 liters water. Widal (TYPHOID). One drop blood serum of a patient suspected of typhoid is added to 10 drops of a typhoid bacillus culture 24 hours old, and stirred together. If the disease is typhoid, small particles will be observed under the microscope consist- ing of coagulated motionless bacteria. If the case be not ty- phoid the organisms will be freely motile. The serum of other infectious diseases exhibits the same conduct. As the reaction originally emanated from Gruber, it is latterly described as- Gruber-WidaV s reaction (compare also Pfeiffer's reaction). Widal-Gruber (TYPHOID). See Widal. Wiederhold (RosiN OILS; MINERAL OILS). Rosin oils dissolve- in acetone in almost every proportion ; mineral oils are mostly quite insoluble. Some few cylinder oils are sparingly soluble. Wiederholt (GENUINE RUM AND COGNAC). Upon treating 10 Cc. of sample with 3 Cc. cone. H 2 SO 4 (sp. gr. 1.84) and allowing mixture to cool, the aroma of pure rum is retained, while that of the artificial product is destroyed. Upon treating pure cognac with a few drops of dil. solut. Fe 2 Cl 6 a black ppt. forms. Artificial cognac does not give this test; at the most,, an ill-colored ppt. is slowly deposited. Wieger-Born (QUINCE MUCILAGE). See Born-Wieger. Wiesner (LIGNIN). i. Woody fibers are stained golden-yellow by an acid solution of aniline sulphate, while pure cellulose is not affected. 2. 0.5-% phloroglucin solut., which, together with HC1, colors woody fibers yellow, is also known as Wies- ner' s reagent. Wildenstein (COPPER AND IRON). A blue color is caused by tincture logwood. Wilder (TURMERIC IN MUSTARD OR RHUBARB). Mix suspected powder with any volatile oil (fennel, anise, etc.) and examine under microscope. If turmeric present, the specks will be sur- rounded by a yellow zone, while the color of the particles of rhubarb or mustard will be brightened. If turmeric absent, 33 2 TESTS AND REAGENTS. the microscopical field will remain colorless, while turmeric, if present, will instantly color the whole or part of the field yellow. Wiley (CHLOROCHROMIC ACID). A blue- violet color develops on adding a small crystal of strychnine to a drop H 2 SO 4 , then stir- ring with a glass rod moistened with chlorochromic acid. Willeband (STAIN FOR BLOOD). Mix equal quantities of a 0.5-% solut. eosine in 70-% alcohol and a cone, aqueous solut. methylene blue. To 50 Cc. of the mixture add by drops 10 to 15 drops of i-% acetic acid. Heat specimens with fluid sev- eral times for 5 to 10 minutes until vapors are given off. Erythrocites are stained red; nuclei, sharply dark-blue; neutro- philes, violet; acidophiles, pure red; mast cells, intensely blue. Wilson (NITROUS ACID). On adding a little resorcin to H 2 SO 4 containing HNO 2 and shaking with 5 Cc. water, a yellow color results. Wimmer (PURITY OF OLIVE OIL). Note effects produced on passing nitrous gas through the oil. Windisch (CHERRY SYRUP IN RASPBERRY SYRUP). Distil 20 to 30 Cc. syrup until 2 Cc. distillate are received. To this add i drop each tincture guaiac and very dil. CuSO 4 solut. a blue fugitive color indicates presence of HCN. If color is faint, add a little chloroform on shaking, chloroform becomes colored. Method also suitable for cherry wine in red wine. Windisch (CHERRY SYRUP IN RASPBERRY SYRUP). Distil 20 to 30 Cc. syrup until 2 Cc. distillate are obtained. To this add i drop each of tincture guaiac and very dil. solut. CuSO 4 a fugitive blue color indicates presence of HCN (from the amyg- dalin in the cherry stone) . Winkler (ALKALOIDS). See Mayer's reagent. Winkler (WATER IN ALCOHOL). Cobalt chloride is turned red if water be present. Winkler (FREE HYDROCHLORIC ACID IN GASTRIC JUICE). Rea- gent is a 5-% solut. (or a io-% chloroformic solut.) of alpha- naphtol. Add a few grains dextrose to filtered gastric juice in a porcelain dish, and then add a few drops reagent. On care- fully heating, a bluish- violet zone forms at close of evaporation (best conducted on a water-bath). With 0.04-% HC1 results are still certain with careful manipulation. Reaction does not TESTS AND REAGENTS. 333 occur if free acid absent; it is afforded, however, by H 2 SO 4 and H 3 PO 4 . Lactic and acetic acids do not give the reaction. Winkler (IODINE). A blue color is produced on addition of so- dium nitrite and starch paste. Winkler (KINOVIC ACID). A dirty-green color and ppt. are pro- duced on adding solut. CuSO 4 . Wislicenus-Landsberg (MORPHINE IN URINE). See Landsberg- Wislicenus. Wissowsky (STAIN FOR BLOOD). First treat with solut. of equal parts of eosine and alum in 200 parts alcohol, then with hema- toxylin. Wittmack (WHEAT AND RYE FLOUR). One Gm. flour is heated with 50 Cc. water on the water-bath to exactly 61 C., so that the temperature rises to 62.5 after removal from the bath. When settled, the deposit is examined microscopically. The starch grains of wheat will not have changed their form, except a slight swelling; those of rye will be nearly all burst and dis- torted. Wittstein (FOREIGN STARCH IN CHOCOLATE). On boiling and filtering, natural starch does not pass through the filter, and the filtrate therefore gives no reaction with iodine. Wittstein (TARRY MATTER IN AMMONIA). A brownish-red color develops on supersaturating ammonia with moderately strong nitric acid if tarry matter present. Witz (MINERAL ACIDS IN VINEGAR). Methyl- violet solut. is turned blue or green on adding 2 drops to 25 Cc. vinegar con- taining mineral acid. Woehler (PHOSPHORUS). Treat suspected liquid in a Marsh's apparatus, ignite gas evolved, and let flame impinge on a porcelain plate. If phosphoretted hydrogen present the flame is colored green. Woehler-Liebig (UREA). See Liebig-Woehler. Woerner (POTASSIUM). A io-% aqueous solut. phosphotung- stic acid gives with neutral or acid potassium salts a white ppt. In acid solut. the ppt. is coarsely crystalline; in neutral solut. exceedingly fine. Slight warmth hastens pptn. Ba, Sr, Ca, and Mg salts are not pptd. by reagent. NH 3 salts are. Wolesky (Wooo FIBER IN PAPER). Dissolve i Gm. diphenyl- amine in 50 Cc. alcohol and 5 or 6 Cc. cone. H 2 SO 4 (or HC1). 334 TESTS AND REAGENTS. According to quantity of wood fiber present in the paper, different shades of orange-red will appear upon moistening with the reagent, and more particularly on drying. Wolf (INDICATOR). Ferric salicylate is specially adapted as an indicator in estimating boric acid in borax, as well as K 2 CO 3 and NaCO 3 . For details see MERCK'S REPORT, x, p. 159. Wolf (Naphtols). Alpha- or beta-naphtol dissolved in alcoholic KOH yields, upon heating with chloroform to 50 C., a clear blue solution, which changes to red upon acidulating with HC1. Reaction first mentioned by Lustgarten. Wolfbauer (COTTON-SEED OIL). Shake 10 Gm. oil for two min- utes with 7.5 Gm. cone. HNO 3 ; when separated add i Gm. mercury and shake for four minutes. Olive oil retains its color, while the presence of 5% cotton-seed oil occasions a brown color. Wolter (HEMATOXYLIN NERVE STAINS), i. Proceed as in Kult- schitzky's method, except that sections should be stained for 24 hours in a solut. kept at 45 Cc. Afterward dip them in Mueller's solution and differentiate by Pal's method. 2. Material hardened in Kultschitzky 's potassium-bichromate and copper- sulphate mixture, followed by alcohol, is imbedded in celloidin or paraffin, and cut. Mordant sections for 24 hours in a mixture of 2 parts of io-% vanadium-chloride solut. and 3 parts 3-% aluminium- acetate solut., wash for 10 minutes in water, and stain for 24 hours in a solut. of 2 Gm. hematoxylin (dissolved in a little alcohol) in 100 Cc. of 2-% acetic acid. Next wash out the sections in 80- % alcohol containing 0.5-% HC1 until they are of a light blue-red color, remove the acid by washing thoroughly in pure alcohol, dehydrate, clear with origanum oil, and mount. Wolter (VANADIUM NERVE STAIN). See Walter's second hema- toxylin stain. Woodbury (ALCOHOL IN URINE). Mix 2 Gm. urine and i Gm. H 2 SO 4 and drop in a fragment potass, bichromate a green color develops on mixing if alcohol present. Delicacy 2 to 3 : i ,000. Woolsey (MORPHINE). A i : 10 infusion of mallow flowers differ- entiates morphine from other alkaloids. Morphine does not change color of infusion; the following alkaloids, however, change it immediately to dark green: Atropine, homatropine, TESTS AND REAGENTS. 335 berberine, brucine, codeine, coniine, hydrastinine , nicotine, and lobeline. Other alkaloids which do not affect the color are the following: Apomorphine, caffeine, cocaine, carpaine, cin- chonine, cinchonidine, colchicine, emetine, hydrastine, hyoscine, narcotine, piperin, physostigmine , quinine, sanguinarine, and strychnine. Wormley (ALKALOIDS), i. Alcoholic solut. picric acid throws down yellow amorphous or crystalline ppts. 2. A solut. containing i part I, 3 parts KI, and 60 parts water, throws down colored ppts. Wormley (FREE SULPHURIC ACID). A crimson color appears on adding a little veratrine and evaporating to dryness on a water- bath. Worm-Mueller (GLUCOSE). Modified Fehling's solution, consist- ing of two solutions, a 2.5-% CuSO 4 solut. and a 4-% NaOH solut. containing 10% Rochelle salt. 5 Cc. suspected urine on the one hand, and i to 3 Cc. CuSO 4 solut. with 2.5 Cc. Ro- chelle-salt solut. on the other, are separately heated to boil- ing and, then mixed without shaking. Fehling's solution (q. v.) according to recent formulas is also prepared and kept on hand as two separate solutions. Wright (ACONITINE). If o.ooi Gm. aconitine is distributed through a few drops moderately cone, sugar solut., and then a drop of cone. H 2 SO 4 added, a rose-red zone will develop at contact line of the sugar solut. and acid, and the color will rapidly change to a dirty violet and brown. Wurster (ALBUMIN). Modification of Silbermanris reaction (q. v.). Instead of cone. HC1, a mixture of the latter with 1 1 I5 - to -J- its vol. cone. H 2 SO 4 is employed. Wurster (TEST-PAPER FOR OZONE), i. Dimethylparaphenyl- enediamine Paper. Used for detecting ozone, with which it gives a bluish- violet color; it is also used for detecting H 2 S, H 2 O 2 , turpentine oil, colophony, and wood-pulp in paper. Wurster ("TETRA "-PAPER FOR OZONE OR HYDROGEN DIOX- IDE). Filter-paper saturated with tetramethylparaphenyl- enediamine. Traces of ozone or hydrogen dioxide in neutral solutions or in solutions acidified with acetic acid afford an intense blue color with the paper. Upon boiling with alcohol 336 TESTS AMD REAGENTS. the blue color disappears. Instead of the tetramethyl- the dimethyl-compound may also be employed. Wurster (TYROSIN, PURITY OF). Dissolve in boiling water and add a little quinone a ruby-red coi~. develops, changing to brown after 24 hours. Wurtz- Pasteur (FUCHSINE IN WINE). See Pasteur-Wurtz. Wynther-Blyth (ALUM IN BREAD OR FLOUR). Process is con- ducted by macerating sample with a small quantity of water and then soaking strips of gelatin in the liquid ; after 1 2 hours the gelatin slips are removed and immersed in a mixture of equal volumes of fresh logwood tincture and sat. ammonium- carbonate solut. In the presence of alum they turn blue. Yvon (ACETANILID ANTiFEBRiN] IN URINE). Extract urine with chloroform, evaporate, and heat residue with mercurous nitrate a green color develops if acetanilid present. Yvon (ALCOHOL IN CHLOROFORM). A solut. of i part potassium permanganate and 10 parts of KOH in 250 parts water was formerly used as a qualitative test, the violet color changing to green on shaking with chloroform containing alcohol. But as alcohol-free chloroform alone stands the test, the reaction is now employed as a means of determining the amount of alcohol present. Yvon (ALKALOIDS). A red color appears on adding a solut. pre- pared by boiling 3 Gm. bismuth subnitrate with 40 Gm. water, 14 Gm. KI, and 40 drops HC1. Yvon (BILIARY PIGMENTS). See Paul's test. Young (GALLIC IN TANNIC ACID). Potassium cyanide gives a red color with gallic acid, but not with tannic acid. The color soon vanishes, but reappears on vigorous shaking. Accord- ing to Stahl the reaction can be referred entirely to the alka- linity of the cyanide. Zacharias (ACETIC- ACID CARMINE). Add to each 10 Cc. of Schneider's solution i drop wood vinegar. Zacharias (ACETIC ALCOHOL). Mix i part of glacial acetic acid with 4 parts absolute alcohol and a few drops osmic-acid solut. Zacharias (ALBUMINS). This reagent is an acidulated solution potassium ferrocyanide and ferric chloride. Zacharias (!RON CARMINE). Stain objects thoroughly for sev- eral hours in acetic-acid carmine or Mayer's carmalum, rinse TESTS AND REAGENTS. 337 with dilut. acetic acid, and pass them into i-% solut. ammo- mated iron citrate, taking care that no metallic instruments touch them. Leave for 2 or 3 hours till thoroughly pene- trated (a few minutes only in the case of sections), then wash for several hours in distilled water, dehydrate, and mount in balsam, Zaleski, Von- (CARBONIC OXIDE IN BLOOD). On adding 2 Cc. water and 2 drops supersaturated CuSO 4 solut. to 2 Cc. blood, a brick-red ppt. results if carbolic oxide present. Normal blood produces a brownish-green ppt. Zaloziecki (INDICATOR). Alpha-naphtolbenzein. Gives with al- kalies a green color, and with acids a reddish-yellow. Zanker (FIXING LIQUID). Dissolve 5% HgCl 2 and some glacial acetic acid in Mueller's solution. Fix objects in this for several hours, wash out with water, and treat the tissues or sections with alcohol containing some tincture iodine. Zechini (PURITY OF OLIVE OIL). Note color reactions produced on adding HNO 3 (sp. gr. 1.4). Zeise (CARBON BISULPHIDE). A yellow ppt. is thrown down on adding a little alcoholic KOH and solut. CuSO 4 . Zeisel (COLCHICINE). A solut. of 0.002 Gm. colchicine in 5 Cc. water changes from yellow to olive-green and then to blackish- green on boiling for i to 3 minutes with 5 to 10 drops fuming HC1 and 4 to 6 drops of io-% Fe 2 Cl 6 solut. Upon shaking solut. with chloroform in the presence of air, the chloroform becomes ruby-red and the aqueous solut. olive-green. Zeller (MELANIN IN URINE). The addition of bromine water to urine containing melanin causes a yellow ppt., changing to black on standing. Zeller (QUININE). This is the thalleioquin reaction, with bro- mine water (i : 40) substituted for chlorine water. Zellner (NATURAL INJECTIONS). Use Mueller's solution. Zencker (FIXING SOLUTION). HgCl 2 , 5 Gm.; K 2 Cr 2 O 7 , 2.5 Gm.; Na 2 SO 4 , i Gm.; water 100. Before use a few drops of acetic acid are added. Ziegler (HYDROCHLORIC ACID). Arsenous and sulphurous acids in HC1 are detected by adding zinc and passing the hydrogen evolved through water containing a few drops ammoniacal copper-chloride solut., then through water containing i drop TESTS AND REAGENTS. solut. AgNO 3 . Any H 2 SO 3 present reacts on the copper salt; arsenous acid affects the silver solut. Ziehen (Gold AND SUBLIMATE STAIN). Leave small pieces of fresh tissue for 3 weeks to 5 months in a large quantity of a mixture containing equal parts i-% HgCl 2 and gold-chloride solutions. When they have assumed a metallic red-brown color, gum them on cork and cut sections without imbedding. Treat the sections with LngoVs solution diluted with 4 times its bulk of water, or with dilute tincture iodine, until duly differentiated; then wash and mount balsam. Ziehl (CARBOLIC FUCHSINE). See Neelsen's solut. carbolic fuchsine. Ziehl- Neelsen (CARBOLIC FUCHSINE). Fuchsine, i Gm. ; car- bolic acid, 5 Gm. ; alcohol, 10 Gm.; dist. water, 100 Gm. Solut. is permanent. Ziehl- Neelsen (STAINING BACILLI). Sections are removed from weak alcohol into Neelsen's carbolic fuchsine and left for 10 or 15 minutes; next decolorize in H 2 SO 4 (sp. gr. 1.84) or HNO 3 (sp. gr. 1.42) diluted with 3 volumes water, rinse in 60- % alco- hol, and wash in a large volume of water to remove the acid. Tubercle and leprosy bacilli are the only micro-organisms that can retain the stain after treatment with acid. If traces of HNO 2 in the HNO 3 be suspected, Squire recommends the use of a sat. aqueous solut. of sulphanilic acid, mixed with one- third its bulk HNO 3 . The sulphanilic acid destroys any free HNO 2 , which would otherwise exercise a bleaching action on the fuchsine-stained bacilli. The sections may be counter- stained with a solution of 0.5 Gm. methyl green (or 0.25 Gm. methylene blue) in 20 Cc. alcohol and 80 Cc. distilled water. Finally dehydrate in absolute alcohol, clear with cedar oil, and mount in balsam. Zouchlos (ALBUMIN IN URINE), i. A mixture of io-% potas- sium-sulphocyanate solut. 100 and acetic acid 20. With albu- min it produces a ppt. or turbidity. Delicacy 0.007%. 2 - 10 Cc. of a 2-% solut. of potassium sulphocyanate with 2 Cc. of acetic acid. 3. Acetic acid, i; mercuric chloride (i-% solut.), 6. Delicacy 0.04%. 4. Potassium sulphocyanate and succinic acid, equal parts, in solid form. TESTS AND REAGENTS. 339 Zuelzer (ALBUMIN). This is a zone reaction which occurs on overlaying albuminous urine upon cone, chromic-acid solut. Zuelzer (GLUCOSE). A solut. of cupric oxide in soda lye is re- duced by grape sugar in the cold or upon gentle warming. Zulkowsky (STARCH SOLUTION). Heat starch with glycerin to 190 C., ppt. with alcohol, and dissolve the ppt. in water. Zune (CULTURE SOLUTION). Gelatin 50 Gm., agar 2.5 Gm., are dissolved in 600 to 700 Gm. sterilized filtered culture-broth. The white of an egg is added, the mixture heated until this is coagulated, then filtered, and the filtrate sterilized at 105 to noC. Zwaardemaker (SAFRANINE STAIN). Mix equal parts of sat. alcoholic solut. of safranine and aniline water. INDEX OF SUBJECTS. Abrastol in Wine. Brand. Absinthin. Mein. Acacia. Hager; Lassaigne; Reiche. Acacia Injection Mass. Bjeloussow. Acetal. Grodyki. Acetanilid. Flueckiger; Moers; Rudolf-Fischer; Stroebel; Vul- pius. IN PHENACETIN: Hirschsohn; Schroeder; Mueller. In URINE: Yvon. Acetic Acid, in Calcium Acetate. Grimshaw. Acetic Acid, Glacial, Furfurol in. Meyer. Acetic Acid, Pyroligneous Matter in. Lightfoot. Acetic- Acid Carmine. Zacharias. Acetic Alcohol. Carnoy; Van Beneden-Neyt ; Zacharias. Acetic Gentian Violet. Friedlander. Aceto-Acetic Acid in Urine. Arnold. Ace to-Carmine. Schneider. Acetone. Gunning; Jolles; Kraemer; Legal; Lieben; Malerba; Messinger; Moerner; Penzoldt; Sternberg; Thorns. IN URINE: Bayer; Chautard; Drewsen; Gerhardt; Legal; Le Noble; Ralfe; Reynold; Sch wicker; Stock. Acid Carmine Solution. Schweigler-Seidel. Acid Mixture. Weissman. Acid Number. Hehner. Acidophilous Mixture. Ehrlich. Acidulated Alcohol. Mayer; Squire. Acidulated Glycerin. Squire. Aconitine. Hassalt; Herbst; Mecke; Melzer; Wender; Wright. Acrolein. Lewin. 341 342 INDEX OF SUBJECTS. Actiniae, Narcotizing Mixture for. Bianco. Actinomycosis. Babes; Plant; Squire; Weigert. Agar-Agar. Gravis. Albumin. Adamkiewicz ; Almen; Alpers; Axenfeld; Barral; Berzelius; Blum; Boedecker; Bogomolow-Wassilieff; Bou- chardat; Bourreau; Cadier; Christen; Cohen; Esbach; Esbach-Gawalowsky ; Fol; Froehde; Frohn; Fuerbringer; Galippe; Gaudail; Gautier; Gawalowsky; Geissler; Gouver; Grigg; Guerin; Guezda; Hager; Haslan; Heidenhain; Heinsius; Heller; Heynsius; Hilger; Hindenlang; Hoffmann; Ilmenow; Jaworowsky; Johnson; Jolles; Krasser; Lugol; Mac William; Mann; Menu; Mesnard; Millard; Millon; Monier; Neubauer; Oliver; Panum; Pavy; Piotrowski; Plugge; Pol- lacci; Posner; Raabe; Rafaele; Ree; Reichl-Mikosch ; Rieg- ler; Rosenbach; Roberts; Roberts- Stolnikoff; Roch; Rose; Schultze; Siebold; Silbermann; Spiegler; Stutz; Tanret; Tidy; Tretrop; Wurster; Zacharias; Zouchlos; Zuelzer. Albumin Fixative for Slides. Mayer. Albuminoids. Bruecke; Guezda; Guerin; Lidof; Lidow; Lieb- ermann; Raspail; Roch. Albumoses. Riegler; Tyson. Alcohol. Bernouilly; Berthelot; Blachez; Boettger; Borsarelli; Casoria; Davy; Debrunner; Drechsler; Fleischmann; Hardy; Istrati; Jacquemart; Lieben; Ludwig; Mann; Otto; Riche- Bardy; Savelle; Thresh; Tscheppe; Vogel; Winkler. In CHLOROFORM: Hardy; Siebold; Yvon. In ESSENTIAL OILS: Barbier; Dragendorff; Forney; Hager; Leonardi; McClellan- Forney; Oberdoerfer; Puscher; Redwood; Salzer; Stuart; Sulzer. In ETHER: Frederking; Hager; Stefanelli. In PERU BALSAM: Gawalowsky. In URINE: Anstie; Woodbury. Alcohol, Absolute. Ranvier. Alcohol, Acetic. Carnoy; Van Beneden-Neyt ; Zacharias. Alcohol-acetic Acid. David. Alcohol, Acidulated. Mayer; Squire. Alcohol, Amylic. Bouvier; Hager; Jorissen. Alcohol and Sodium Chloride. Moleschott-Piso-Borme. Alcohol- Balsam. Seiler. Alcohol, Methyl. Cotton-Cazeneuve; Jacquemart; Milliken- Scudder. In ETHER: Langbeck. INDEX OF SUBJECTS. 343 Alcohol, One-third. Ranvier. Alcohol, Picric. Gage. Alcohol, Strength of. Squire. Alcoholic Carmine. Mayer. Alcohols and Amines. Schotten-Baumann. Alcohols, Monatomic. Bitto. Alcohols, Polyatomic. Baumann. Aldehydes. Bela-Von Bitto; Crismer; Erdmann; Fischer; Gayon-Gannon-Molher; Golding-Bird; Greenwalt; Istrati; Guy on; Lewin; Liebig; Molher; Nessler; Penzoldt-Fischer ; Riegler; Rimini; Schiff; Tollens; Villiers-Fayolle. Aldoses. Sieben. Alizarine. Schaal. Alkalies. Bachmeier; Dobbin; Filhol; Griessmayer ; Jacque- min; Schweissinger. SULPHITES OF: Alvarez-Jean. WITH SULPHITES: Grant-Cohen. Alkaline Aniline Water (Weak). Loeffler. Alkaline Glycerin Mountant. Kirkby. Alkaline Methylene Blue. Loeffler (see " solution "); Schiitz. Alkaline Permanganate Solution. Wanklyn. Alkalinity of Water. Cavalli. Alkaline Salts, Arsenic in. Patrouillard. Alkaloids. Arnold; Arnold- Vitali ; Bertrand; Bloxam; Bou- chardat ; Brissemoret (opiitm) ; Buckingham ; Czumpelitz ; Defacqz; Delff; Dragendorff; Dunstan; Ransom (in bella- donna extr.); Dwar (cinchona); Eboli; Elias; Erdmann; Erd- mann-Uslar; Errera; Formanek; Fraude; Froehde; Frohn; Godeff roy ; Godeffroy - Laubenheimer ; Graham - Hoffmann ; Grandeau; Hager; Hamlin; Hesse; Hoffmann; Horsley; How; Jacquemin; Jaworowsky; Johannson; Jorissen; Jungmann; Kippenberger ; Kohler; Krant; Langley; Langley-Koehler; Laubenheimer-Godeffroy ; Lenz; Lepage; Lindemann-Motten; Lindo; Lloyd; Luchini; Mandelin; Mangini; Marchand (cin- chona); Marme; Mayer; Mecke; Melzer; Motten-Lindemann ; Neumann- Wender ; Nowak-Kratschmer; Orlow-Horst; Otto; Otto-Stas; Palm; Pasteur; Pesci; Planta; Prollius (solut. for extracting); Ransom- Dunstan (in belladonna extr.); Robin; Rossbach; Scheibler; Schering; Schlagdenhauffen ; Schneider; Schultze; Schwarzenbach-Delff ; Schwarzenberg; Sedgwick;; 344 INDEX OF SUBJECTS. Selmi; Sonnenschein ; Stas-Otto; Strzyzowski; Thresh; Tro- tarelli; Uslar-Erdmann; Valzer; Verven; Vitali; Vitali- Arnold ; Vrij , de- ; Wagner ; Wender ; Wenzel ; Winkler ; Wormley ; Yvon. Aloes. Borntraeger; Cripps-Dymond; Dieterich; Hirschsohn; Schonteten; Schunke-Mulder; Stoeder. Aloin. Histed; Tilden. Alpha- Naphtol. Aymonier; Leger; Vincent; Liebmann. Alum in Bread or Flour. Carter-Bell; Wynter-Blyth. Alum-Carmine. Grenadier; Henneguy; Tangl. Alum-Carmine, Cochineal. Partsch. Alum-Carmine Picric- Acid Stain. Legal. Alum-Cochineal. Csokor (or Czoker) ; Rabl. Aluminium. Thenard. Aluminium-Chloride Carmine. Mayer. Aluminium Sulphate, Free Acid in. Hager; Giesecke. Amines. Hoffmann ; Schotten-Baumann. Ammonia. Boettger; Bohlig; Chevreul; Fleck; Guyot; Hager; Jaworowski; Kroupa; Kupf erschlaeger ; Lex; Moddermann; Schultze; Selle; Wittstein. In URINE: Neubauer; Lat- schenberger. Ammonia Carmine. Beale; Betz; Frey; Hartig; Malassez; Ranvier. Ammoniac. Picard; Plugge. Ammoniacal Gentian Violet. Weigert. Ammonia ted Hematoxylin. Ehrlich. Ammonium-Chloride Solution. Wanklyn. Ammonium Molybdate. Altmann. Ammonium Salts. Einbrodt ; Nessler. Ammonium Thiosulphate. Orlowski. Amygdalin. Deacon; Heuschen. Amyl Nitrite, Hydrocyanic Acid in. Hager. Anethol. Chapman. Aniline. Beissenhirtz; Duflos; Hoffmann; Jacquelin; Letheby; Ludwig; Rosenstiehl; Runge. Aniline-Blue Indigo-Carmine. Duval; Naschold. Aniline-Clove-Oil Stain. Kuehne. Aniline Colors. Blarey. Aniline-Fuchsine Stain. Koch. Aniline- Orange in Milk. Lythgoe. INDEX OF SUBJECTS. 345 Aniline Salts. Hoffmann. Aniline Solutions. Kuehne. Aniline Stain. Hanstein. Aniline Water. Ehrlich-Weigert-Koch ; Koch. Animal Fats in Petrolatum. Crouzel-Dupin. Animal Fibers. Boettger; Frankenstein. Aniseed- Oil Freezing Mass. Kuehne. Anise-Oil Imbedding Process. Moore. Annelids, Fixing Fluid for. Ehler. Anthraquinone. Schuetzenberger ; Wartha. Antifebrin in Urine. Mueller. Antimonous Acid. Mohr. Antimony. Rideal. Antimony Hydride. Hager. Antinervin. Strobel. Antipyrine. Strobel. Apiol. Jorissen. Apomorphine. Bedson; Mecke; Melzer; Wangerin. Aqueous Carmine Injection. Emery. . Arabin for Serial Sections. Waddington. Arbutin. Jungmann. Aromatic Substances in Blood. Danielewsky. Arsenic. Berzelius; Bettendorf; Bougault; Braconnot; Bujwid; Cadet; Carnot; Davy; Fleitmann; Flueckiger; Fresenius- Babo; Gatehouse; Gutzeit; Hager; Hilger; Himmelmann; Johnson; Hume; Letheby; Marsh; Mayencon-Bergeret; Mor- ton; Naylor-Braithwaite; Oster; Patrouillard ; Puscher; Rei- chard; Reinsch; Rideal; Scheele; Schiff; Schlickum; Schnei- der; Siebold. Arsenic Hydride. Hager; Flueckiger. Asiatic-Cholera Bacillus, Products of. Dunham-Bujwid; PoehL Asphalt Injection Mass. Budge. Asphalt Varnish. Kitton. Atmosphere, Mercury Vapors in. Gaglio. Atropine. Gerrard; Gulielmo; Herbst; Hinterberger; Kuborne; Mecke; Melzer; Reuss; Robin; Vitali; Wender. Bacilli Stain. Schultz; Ziehl-Neelsen. Bacteria Culture-Solution for. Fraenkel-Voge; Uschinsky. Bacteria Cultures, Examining. Bates. 346 INDEX OF SUBJECTS. Bacteria, in Potable Water. Gottstein. Bacteria, Products of, in Urine. Baumann. Bacteria Stain. Blanchard; Ehrlich (gentian- violet ); van Er- mengen; Ernst; Fischer (for cilia); Gram; Gunther; Koch; Kuehne; Loeffler; Lugol; Schutz- Weigert ; Weigert. Balsam, Canada, for Imbedding. Weil. Balsam Copaiva. Dodge-Olcott; Hager (castor oil; fatty oil); Hirschsohn (fatty oils, gurjun balsam) ; Maupy (castor oil) ; Muter (fatty oil). Balsam Gurjun in Copaiba. Hager; Hirschsohn. Balsam Peru. Gawalowski (alcohol); Gehe; Hager (benzoin); Hirschsohn (rosin). Balsam Tolu. Hirschsohn (rosin). Beer. Brand (fluorine); Hefelmann-Mann (fluorine); Rust (picric acid) ; Schuster (coloring matter). Beeswax, Paraffin in. Landott. Belladonna Extract, Alkaloids in. Dunstan-Ransom. Belladonna. Stoeder ; Wasilewsky . Benzaldehyde in Bitter-almond Water. Spasski. Benzene. Biel; Brandberg; Dragendorff; Gawalowsky; Hoff- mann; Lainer; Pusch; Thorns. Benzidine. Julius. Benzin. Biel; Brandberg; Dragendorff; Gawalowsky; Lainer; Pusch; Thorns. Benzoazurin Stain. Martin. Benzoic Acid. Bodde; Phipson; Schacht; Schneider; Thorns. In BENZONAPHTOL: Griggi. Benzonaphtol. Griggi (benzoic acid). Benzoin in Balsam Peru. Hager. Benzoins. Hirschsohn. Berberine. Klunge; Perrins. Bergamot Oil. Gulli (oil turpentine). Berlin-Blue Gelatin Mass. Fol; Hager. Berlin-Blue Injection Mass. Bruecke; Mayer; Mueller. Beta-Naphtol. Liebman (alpha-naphtol) ; Vincent. Bicarbonates in Carbonates. Lunge. Bilberry- Juice Stain. Lavdowsky. Biliary Acids. Bischoff; Francis; Hay; Kuelz; Mylius; Neu- bauer; Oliver; Pettenkofer; Strassburg; Udransky. INDEX OF SUBJECTS. 347' Biliary Pigments. Barral; Hartley; Basham; Brueck; Ca- pranika; Casali; Cunisset; Deubner; Dragendorff ; Drechsel; Dumontpallier ; Dumontpallier- Trousseau ; Fleischl; Gerard; Gerhardt; Gmelin; Heintz; Heller; Hilger; Hoppe-Seyler ; Huppert; Jolles; Krehbiel; Lewin; Marechal; Masset; Neu- komm; Noel; Paul; Penzoldt; Riegler; Rosenbach; Rosin; Schwanda; Seyler-Hoppe; Smith; Tiedemann- Gmelin ; Tri- ollet; Trousseau- Dumontpallier; Ultzmann; Vitali; Yvon. Bilifuscin. Hoffmann- Ultzmann. Bilirubin. Maly. In BLOOD: Jaksch, von-. In URINE: Green- wait; Ott; Proescher. Bismuth. Field; Kobell; Leger; Muir; Schneider; Thresch. Bitter- Almond Water. Spasski (benzaldehyde). Biuret. Bruecke; Piotrowski; Rose. Black-Brown. Kuhne. Bleach. Grenacher; Pal; Ramsay (also known as Crowell's). Bleaching. Overton (osmic objects) ; Unna (chromic objects). Bleaching Methods. Carizzi; Gilson; Marsh (chlorine); Mayer; Pouchet; Sargent. Bleu-de-Lyon Stain. Baumgarten. Blood. Almen; Bertoni-Raymondi (HN0 2 ); Binz (CO); Bre- mer (glucose); Danielewsky (aromatic substances); Deen, van-; Falk; Ferrier; Garrod (uric acid); Helwig; Huehne- feld; Jaksch, von- (bilirubin); Laden dorf; Luff (uric acid); Preyer (CO); Raymondi-Bertoni (HNO 2 ); Salkowsky (CO);. Schaer ; Schoenbein ; Selmi ; Sonnenschein ; Struve ; Teich- mann; Van Deen; Vitali; Weber; Wetzel (CO); Zaleski, von- (CO). In URINE: Heller-Teichmann ; Huehnefeld; Lechini; Rossel. Blood Corpuscles, Fixing Solution for. Hayem. Blood Microscopical Examination. Hayem. Blood Stains. Ganther; Kastenbine; Moore (eosine); Toison; Willebrand ; Wissowsky ; Rosenbach. Blood, Turpentine Solution for Testing. Huehnefeld. Blueing Sections. Mayer; Squire; Wistinghausen. Bone Decalcification. Busch. Bone Staining. Busch. Bone, Sections of. White. Borax. Turner. In MILK: Hosaeus. .348 INDEX OF SUBJECTS. Borax Carmine. Bourne; Gibbes; Grenacher; Mayer; Thiersch. Borax Carmine, Lilac. Thiersch. Boric Acid. Wade. Borofuchsine. Luebimoff. Brain, Formaldehyde for Hardening. Von Gieson. Brain Tissue Stain. Weigert. Bread, Alum in. Carter Bell; Wynther-Blyth. Bromic Acid in Urine. Rabuteau. Bromates. Pages. Bromides. Berzelius; Bill; Jones. Bromine. Castle; Henry-Humbert; Jorissen (iodine); Troost; Vitali. Brucine. Cotton; Dragendorff; Flueckiger; Gerhardt; Hager; Lyon (mixture for extracting); Mecke, Melzer; Pellagri; Short- Dunst an ; Wender. Butter. Bach; Bischoff (melting-point); Bolley; Crook; Drouot (margarin); Erdelyi (foreign fats); Filsinger; Hager; Hummel; Jahr (melting-point); Pirette; Reichert-Miessl (foreign fats); Rideal (hydrolysis) ; Schoenvogel (foreign fats) ; Wibel (water), Butter Yellow (Martius Yellow) in Urine. Vitali. Cacao Butter. Bjorklund; Filsinger; Hager. Cadmium. Deniges. In URINE: Marme. Cadmium Coloring Mass. Robins. Caffeine. Archetti; Delff; Mecke; Rochleder; Stenhouse. In URINE: Hammarsten. Cajuput Oil, Cineol in. Faulding. Calcium. Sonstadt. Calcium Acetate. Grimshaw (acetic acid). Calculi, Urinary. Deniges (uric acid). Camphor in Spirit Camphor. Mansier. Canada Balsam. Squire. Canada Balsam for Imbedding. Weil. Cane Sugar. Papasogli; Reich; Runge. In MILK SUGAR: Conrady. Cannabis Extract. Proctor. Cantharidin. Eboli; Melzer. Capsule Stain. Friedlander; Ribbert. Caramel in Liquor and Vinegar. Crampton-Simons. INDEX OF SUBJECTS. 349 Carbohydrates. Baumann; Fischer; Molisch; Schiff; Udran- sky-Baumann. In URINE : Baumann. Carbolfuchsine. Kuehne; Neelsen; Schenck; Ziehl; Ziehl- Neelsen. Carbol-glycerin-fuchsine. Czaplewski. Carbolic Acid. Almen; Guareschi; Hager; Manseau; Prescott; Read; Rice; Runge; Rust; Thorns; Tommasi. " Carbolic " Disinfectants, Crystallizable Phenols in. Lowe. Carbolic Methylene Blue. Kuehne. Carbon Compounds. Nickel. Carbon Bisulphide. Hoffmann; Vogel; Zeise. In OIL MUS- TARD: Luck. Carbon Monoxide. Boettger; Hoppe-Seyler (poisoning). In BLOOD: Binz; Preger; Salkowsky. Carbonates. Lunge (bicarbonates) ; Mueller (NaOH). Carbonic Acid. Pettenkofer. Carbonic Oxide. Merget; Mermet. In AIR: Potain-Drouin. In BLOOD: Wetzel; Zaleski. Carbonyl Chloride. Ramsey (in CHC1 3 ). Carmine. Hoyer. Carmine, Acetic-Acid. Zacharias. Carmine, Aceto-. Schneider. Carmine, Alcoholic. Brass; Grenacher; Mayer. Carmine Alum. Grenacher; Henneguy; Mayer; Tangl. Carmine, Aluminium-Chloride. Mayer. Carmine, Ammonia. Beale; Betz; Frey; Hartig; Malassez;: Ranvier. Carmine Aniline-Blue Method. Duval. Carmine Blue. Jansen. Carmine, Borax-. Bourne; Gibbs; Grenacher; Mayer; Thiersch. Carmine Coloring Mass. Robins. Carmine Gelatin Mass. Fol; Hoyer; Ranvier. Carmine Glycerin Mass. Beale. Carmine, Hydrochloric- Acid. Grenacher. Carmine- Indigo Carmine. Mayer. Carmine Injection. Emery (aqueous); Thiersch (mass); Ville (mass). Carmine, Iron-. Zacharias. Carmine, Lilac-Borax. Thiersch. 35 INDEX OF SUBJECTS. Carmine Method. Cole. Carmine, Neutral. Boehn; Heidenhain. Carmine, Oxalic- Acid. Thiersch. Carmine, Picro-. Vignal-Ranvier. Carmine Solution. Cuccati; Hamann; Schweigler-Seidel (acid). Caryophylline. Burgess. Cassia Oil. Hirschsohn. Castor Oil. Bollet; Draper; Finkener (adulterations); Vetere, di-. InCopAivA: Hager; Maupy. In CROTON OIL: Maupy. In OLIVE OIL: Leonard!; Vetere, di-. Catechu. Dieterich. Caustic Alkali. Dobbin; Mueller (in carbonates). Caustic-Potassa Number. Koettstorfer. Cedar Wood Oil in Spearmint Oil. Kremers-Schreiner. Cell-nucleus Stain. Grenacher. Celloidin. CEMENT FOR BLOCKS: Johnson. CLEARING SEC- TIONS: Nikiforow; Weigert. MOUNTING SECTIONS: Lee. IMBEDDING MASS: Viallanes. IMBEDDING METHOD: Lee. SOLUTION: Busse; Elsching. Cellulose. Kaiser; Lidoff; Lifschuetz; Mangin; Schultze; Schweitzer; Terreill. SOLVENT: Cross-Bevans; Hoffmeister ; Schweitzer. Cement. Beale; Carnoy (tolu); Csokor or Czoker (turpentine); Eulenstein; Johnson (celloidin); Kitton (white-lead);' Kro- nig; Lovett; Marsh (gelatin); Stieda. Cephaeline. Paul-Cownley. Chelerythrine. Orlow-Horst. Chelidonine. Orlow-Horst. Cheno podium Seeds in Flour. Vogel. Cherry Syrup in Raspberry Syrup. Windisch. Chinoline . Anderson . Chitin, Stain for. Bethe. Chitinous Objects, Shellac Method. Hyatt. Chloral Hydrate. Fairthorne; Hirschsohn (alcoholate) ; Jawo- rowski; Ogston; Schaer-Van Ankum (alcoholate). JELLY: Gilson. MEDIUM: Brady; Lavdowsky. REAGENT (for vola- tile oils and resins) : Hehn. SOLUTION: Munson. Chlorates. Braun; Deniges; Fages; Jean- Alvarez ; Vitali. Chloric Acid in Urine. Edlefsen ; Rabuteau. INDEX OF SUBJECTS. 351 Chlorides. Jones; Jean- Alvarez ; Mohr. Chlorine. Marsh (bleaching sections) ; Riley ; Vitali. Chlorine-Hydrochloric Acid. Villiers-Fayolle. Chlorochromic Acid. Wiley. Chloroform. Hardy (alcohol); Hoffmann; Ramsey (carbonyl chloride); Siebold (alcohol); Staedeler; Vitali; Werner (amy- lic alcohol); Yvon (alcohol). In ESSENTIAL OILS: Hager. In URINE : Neubauer. Chloro-Formic Acid. Rabl. Chocolate, Starch in. Wittstein. Cholera. Koch ; Pfeiffer (serum reaction). Cholera Bacillus, Products of Asiatic. Bujwid- Dunham; Poehl. Cholesterin. Burchard; Hager; Hesse; Liebermann; Lieb- reich; Moleschott; Obermueller; Salkowsky; Schiff; Tschu- gaeff. Cholesterin Fats. Burchard; Liebreich. Chromates. Schiff. Chromic Acid. Barreswil; Donath; Mandel (for proteids); Merkel; Storer. Chromic Objects. Unna (bleaching) ; Virchow. Chromium. Rideal-Rosenblum (compounds). Chromo-Acetic Acid. Bianco. Chromo-Aceto-Osmic Acid. Mark. Chromo-Osmic Acid. Flesch. Chrysammic Acid. Finkle. Cilia of Bacteria. Van Ermengen (stain). Cinchona Alkaloids. Dwar; Pasteur; Paul-Cownley (cupreine); Prollius (solut. for extracting); Jaworowski; Marchand. Cinchona Barks. Grahe. Cinchonidine. Paul (in quinine sulphate); Schaefer (in quin. sulphate). Cinchonine. Bill-Seligsohn. Cineol. Faulding (in oil cajuput and eucalyptus). Cinnamic Acid. Simon; Thorns. Citral. Burgess. Citric Acid. Cailletet; Chapman-Smith; Deniges; Hager; Papasogli-Poli ; Pusch; Sabanin-Laskowski ; Smith-Chapman; Stahre. In LEMON and LIME JUICE: Warrington. In WINE: Nessler. 352 INDEX OF SUBJECTS. Citronellal. Burgess. Citrophen. Moers. Cleaning Solution for Glass Slides. Seller. Clearing Mixture. Dunham; Eyclesheimer; Gage; Nikiforow. Clearing Sections. Kirkby. Clove Oil. Flueckiger (phenol). Coal Gas. Boettger. Coal-tar Dyes in Wine. Cazeneuve; Girard. Cobalt. Danziger; Deniges; Gassini; Papasogli; Schoenn; Skey; Tattersall. Cobaltous Chloride. Stahl. Coca. Gunn. Cocaine. Biel; Giesel; Greitherr; Kuborne; Lewy; MacLagan; Mecke; Melzer; Metzger (Mezger); Orlow-Horst; Schaerge;. Schell. Cochineal Alum. Csokor (Czoker); Rabl. Cochineal Alum-Carmine. Partsch. Cochineal Fluid. Klein. Cochineal Stains. Mayer. Cochineal Tincture. Schlickum. Codeine. Arnold; Dragendorff; Faby; Herse; Hesse; Kobert; Mecke; Melzer; Robin; Schneider; Tattersall; Wender. Cod-liver Oil. Meyer. Cognac, Genuine. Wiederholt. Colchicine. Flueckiger; Hager; Kubel; Mecke; Melzer; Snow; Wender; Zeisel. Colophony. Kleinenberg. Colophony Mounting Medium. Lee. Coloring Matter. In BEER: Schuster. In URINE: Mai-Hilger. In WINE: Boettger; Dupre; Faure; Heise; Hertz; Hilger- Mai. Coloring Matter, Egg. Thudichum. Colors. ACID and BASIC: Weingaertner. ANILINE: Blarez. GREEN: Puscher (arsenic). Coniine. Heut; Liebig; Mecke; Melzer; Stroppa- Vitali ; Wender. Copaiba. Dodge-Olcott; Gerber (fixed oils); Enell (gurjun bals.); Hager (castor oil; fatty oils; gurjun bals.; turpentine) ;. Hirschsohn (fatty oils; gurjun bals.); Muter (fatty oils). In URINE: Nobel. INDEX OF SUBJECTS. 353 Copal Method. Koch; Von Koch. Copper. Bach; Bellamy; Brown; Campani; Cresti; Endemann- Prochazka; Fleitmann; Hatschett; Jaworowski; Purgotti; Sabatier; Sabatin; Schoenbein; Wildenstein. In OILS: Cail- letet. In PRESERVED PEAS: Nikitin. In PRESERVES: Tschirch. In URINE: Hahnemann. In VINEGAR: Hager. In WATER: Guldensteeden. Copper-Ferrocyanide Coloring Mass. Robins. Copper-Hematoxylin. Benda. Copper Sulphate. Griggi (iron); Thorns. Coriander Oil. Schimmel. Corn-Cockle Seeds in Flour. Petermann. Cornutine. Keller. Corrosion Method. Altmann; Noll. Cotton. Boettger; Jacquemin; Liebermann. In WOOLLEN FABRICS: Jandrier; Overbeck. See also CELLULOSE. Cottonseed Oil. Bechi; Deiss; Halphen; Hirschsohn; Labiche; Millian ; Tortelli-Ruggieri ; Wolfbauer. In LARD : Conroy ; Gantter. In OLIVE OIL: Brulle; Hauchecorne; Heydenreich. Creatin. Hofmeister; Kerner; Loew; Weyl. Creatinine. Engel; Joffe; Kerner; Kolisch; Maschke; Salkow- . sky; Thudichum; Weyl. In URINE: Grocco; Stillingfleet- Johnson. Creosote. Clark; Flueckiger; Fonzes-Diacon; Frisch; Gorup- Besanez; Morson; Read; Rust; Thorns; Vreven. Creosote Mounting Mixture. Beale. Croton Oil. Maisch; Maupy (castor oil). In TINCT. IODINE: Durien. Cruciferous Oils. Grehant; Miahle. In OLIVE OIL: Schneider. Crystallizable Phenols in "Carbolic" Disinfectants. Lowe. Crystals. Roussin . Culture Medium. Pasteur; Raulin. Culture Solutions. Cohn; Fraenkel- Voge ; Miquel; Uschinsky; Ztine. Cupraloin. Klunge. Cupreine in Cinchona Alkaloids. Paul-Cownley. Curarine. Dragendorff; Flueckiger. Curcuma. Howie; Maisch. Curcuma Ferment Paper for Urea. Musculus. 354 INDEX OF SUBJECTS. Cyanides. Carey Lea; Hannay; Liebig. Cystein. Andreasch. Cystine. Baumann-Goldman; Liebig; Moer, vande-; Mueller; Rauwerda. Dahlia Stain. Ehrlich. Dammar Solution. Pfitzner; Squire. Decalcification Fluids. Bayerl; Busch; Ebner, von-; Fol; Gage; Haug; Hopewell-Smith (teeth); Marsh; Ranvier; Squire; Thoma; Waldeyer. Decomposed Sausage. Eber. Delphinine. Mecke; Melzer; Tattersall. Desilicification Process. Mayer. Dextrin. Lipp. In ACACIA: Hager. Dextrin Freezing Mass. Webb. Diacetic Acid in Urine. Jaksch, Von-. Diamines. Baumann. Diazo Reaction. Brunner; Ehrlich; Friedewald-Ehrlich (ty- phoid and tubercle). Diazo Compounds. Liebermann. Digestion Fluid. Beale; Bickfalri; Bruecke; Kuskow; Schieffer- decker. Digitalin. Dragendorff; Flueckiger; Lafon; Melzer; Otto; Pape; Wender. Digitalis. Keller- Kiliani . Digitalis Principles. Keller. Dmitroamido-phenate. Frebault (indicator) . Dionin. Kobert . Diphenylamine-Sulphate Solution. Kopp ; Pollet. Dissociation Medium. Stirling. Double Imbedding Method. Kultschitzky ; Ryder. Double Stain. Benda; Gibbs; Kossinski; Seiler; Stile. Dragon's Blood. Hirschsohn. Duboisine. Emden, Van-. Dulcin. Wender. In BEVERAGES: Morpurgo. Dyes, Aniline. Blarez; Letheby; Ludwig. In WINE: Cazen- euve; Girard. Dyes, Artificial, in Wine. Arata. Dyes, Green. Puscher (arsenic). Egg Coloring Matter. Thudichum. INDEX OF SUBJECTS. 355 Elaterin. Dragendorff; Lindo; Power. Embryo Stain. Allen. Emetine. Paul-Cownley; Podwyssotzki ; Power; Snelling. Eosine. Baeyer; Moore (blood stain); Wagner. Eosine-Methyl Green. Calberla. Eosine-Methylene Blue. Chenzinsky. Eosine-Hematoxylin. Cole (method) ; Everard-Demoor-Mas- sart; Hickson (method); List (stain); Massart; Renaut. Epithelium. In URINE: Jakobsohn (stain for). MACERATION METHOD: Minot; Mitrophanow. Ergot. Keller (ergotinine). In RYE FLOUR: Boettger. Ergotinine in Ergot. Keller. Eserine. Da Silva; Saul. Essential Oils. Barbier (alcohol); Flueckiger; Forney (alcohol); Hager (alcohol; chloroform); Hoppe; Leonardi (alcohol); Leuch (water); McClellan-Forney (alcohol); Maier (turpen- tine); Maisch; Merz (turpentine); Oberdoerffer (alcohol); Perrot ; Redwood (alcohol) ; Rhein (fixed oils) ; Salzer (alcohol) ; Stuart (alcohol); Sulzer (alcohol); Walz (fixed oils). Estragol. Chapman. Ether. Boettger (water); Frederking (alcohol); Hager (alco- hol); Langbeck (methyl alcohol); Mann (water); Napier (water); Romei (water); Stefanelli (alcohol). Ethereal Oils. Elram; Puscher (alcohol); Tuschen. Eucalyptus Oil. Faulding (cineol). Eugenol. Burgess ; Chapman. Euphorbium. Flueckiger. Eupittonic Acid. Hoffmann (indicator). Exalgin. Moers. Examination Liquid. Henking (ova); Pictet. Excrements in Oil and Water. Finkelberg. Exposure Mounting. Cole. Extract Belladonna. Dunstan-Ransom (alkaloids in) ; Stoeder. Extract, Cannabis. Procter. Extract Henbane. Stoeder. Extracts, Fluid, Glycerin in. Linde. Extraneous Organisms Among Typhoid Fever Bacilli. Parietti. Fabrics, Textile. Lidoff; Liebermann; Mangin. 356 INDEX OF SUBJECTS. Fats. Allen; Burchard; Holde; Valenta; Welmann. In BUT- TER: Erdelyi; Reichert-Meissl; Schoenvogel. In MILK: Adams; Leffman-Beam; Werner- Schmidt. In PETROLATUM: Cr ouzel- Dupin. Fatty Acids. David; Geitel. Fatty Oils. Barbot ; Behren ; Boudart ; Cailletet ; Crace-Calvert ; Glaessner; Jacobsen; Livache. In COPAIVA: Hager; Hirsch- sohn; Muter. In MINERAL OILS: Lux. Fecal Matter in Water. Griess. Ferment Paper for Urea. Musculus. Ferric-Chloride Stain. Fol; Hoggan. Ferric Salts. Porret; Vogel. Ferruginous Nucleins. Just (iron). Fiber. ANIMAL: Boettger; Frankenstein. COTTON: Boettger. LINEN: Boettger. SILK: Peltier. TEXTILE: Persoz. VEG- ETABLE: Frankenstein. WOOD (in paper): Friedlander; Wolesky. WOOL: Lidoff; Peltier. Fibrin Stain. Weigert. Fixative. ALBUMIN: Fol; Mann; Mayer. GELATIN: Fol. SHELLAC: Giesbrecht; Mayer. Fixed Oils. Bieber; Calvert; Hager; Heidenreich; Massie; Merz; Nickles; Poutet; Roth; Royere, de la-; Ruempler. In COPAIVA: Gerber. In ESSENTIAL OILS: Rhien; Walz. Fixing Liquid. Altmann; Bedot (pelagic animals); Blanc (infusoria); Carter; Ehler (annilids); Eisig; Flemming; Foa; Fol; Fraenkel; Friedlander; Gaule; Hayem (corpuscles); Heidenhain; Klein; Kollmann; Kultschitzky ; Lang; Merkel; Niessing; Perenyi; Podwyssotzki ; Rabl; Schenck; Zanker; Zencker. Flagella Staining. Bunge; Crookshank; Hessert ; Koch ; Loeffler ; Lutesch; Nicholle-Morax ; Sclavo; Trenkmann; Van Ermen- gem. Flavescin. Lux (indicator). Flax. Liebermann. Flour. Carter-Bell (alum); Donny (leguminous flour); Himly (mineral substances); Lassaigne; Steenbuch; Vogel (cheno- podium seed; bran; corn-cockle; vetch; ergot; buckwheat); Wynter-Blyth (alum);. In STARCH: Boettger. Fluid Extracts. Linde (glycerin). INDEX OF SUBJECTS. 357 Fluorine. In BEER: Brand; Hefelmann-Mann. In WINE: Niviere- Hubert. Fluorescin-Clove-Oil Stain. Kuehne. Formaldehyde. Hehner; Lebbin; Pilhastry; Richmond-Bosely ; Rimini. In MILK: Hehner. MIXTURE: Gage; Durig; Her- mann; Kopsch; Lavdowsky; Lee; Parker-Floyd. STAIN: Ohlmacher. Formalin Method. Gieson, Van-. Formic Acid. Broccardi; Lieben; Ranvier. Frangulin. Phipson . Free Acids. Donath; Duflos; Herzberg; Mohr (mineral); Rheoch (mineral); Smith. In ALUMINIUM SULPHATE: Hager. In FIXED OILS: Ruempler. Freezing Mass. Jacob; Kuehne (aniseed oil); Webb (dextrin). Freezing Process. Cole; Rollett. Fructose. Seliwanoff. Fruit Jellies, Gelatin in. Henzold. Fruit Juices, Fuchsine in. Puscher. Fruit Syrups, Fuchsine in. Romei. Fuchsine. Chancel; Valentin. In FRUIT JUICES: Puscher. In FRUIT SYRUPS: Romei. In WINE: Geissler; Pasteur- Wurz; Pradines. Fuchsine Bacteria Stain. Kuehne. Fuchsine-Me thylene Blue . B aumgarten. Fuchsine Solution. Frey. Fuchsine Stain for Nerve Cells. Nissl. Furfurol in Glacial Acetic Acid. Meyer. Fusel Oil. Betelli; Vitali. In ALCOHOL: Savelle. Gallic Acid. Dudley; Flueckiger; Gayard; Griggi; Guyard; Hager; Oliver; Proctor; Watson. In TANNINS: Young. Gas, Inflammable. Clowes. Gas, Illuminating, in Water. Himly. Gastric Juice (Hydrochloric Acid). Contejean; Ewald; Guenz- burg; Kost; Luttke; Maly; Miller, van-; Mohr; Rabuteau; Riegel; Schuchardt; Siringo; Szabo; Toepfer; Van der Velden; Velden; Winkler. Gelatin. Carey Lea. In FRUIT JELLIES: Henzold. Gelatin-Carmine Injection. Ranvier. Gelatin Cement for Glycerin Mounts. Marsh. 358 INDEX OF SUBJECTS. Gelatin Fixative. Fol. Gelatin, Glycerin-. Kleb. Gelatin Mass. Robins. BERLIN-BLUE: Fol; Hoyer. CARMINE: vFol; Hoyer. IMBEDDING: Brunotti; Sollas. LEAD-CHRO- MATE: Hoyer. SILVER-NITRATE: Hoyer. Gelatin Process. Alleger; Gray. Gentian- Violet Method. Bizzozero; Ehrlich; Flemming; Nissen. Globulin. Kauder; Pohl. In URINE: Hammarsten; Paton; Senator- Lehmann. Glucose. Agostini; Almen; Almen-Ny lander; Baeyer; Barfoed; Barreswil; Boettger; Braun; Bremer; Bretet; Bmecke; Bruns-Bizzari; Caillian; Campani; Cappagnoli; Cassamajor; Crismer; Dudley; Duyk; Fabre-Domergue; Focke; Franqui- Van de Vyvere; Frommerherz ; Gerrard; Grismer; Hager; Haine; Haines; Heinrich; Heller; Horsley; Huizinga; Jawor- owski; Knapp; Krueger; Lagrange; Lehmann; Lindo; Loewe; Loewenthal; Maschke; Mathieu-Plessy ; Maumene; Mazzara; Mohr; Moore; Moore-Heller; Mulder; Neumann- Wender ; Nylander; Oliver; Pasteur; Pavy; Peligot; Pellet; Pelouze; Pollacci; Power; Pratesi; Purdy; Quirini; Reich; Riegler; Roberts; Rosenbach; Ruber; Rubner; Sachsse; Sachsse- Heinrich; Schiff; Schmidt; Schmiedeberg ; Schreiter; Soldaini; Tollens; Trommer; Violette; Vogel; Warren; Wayne; Wender; Wender- Neumann; Whitney; Worm-Mueller; Zuelzer. Glucose Medium. Brun. Glucosides. Brunner; Formanek; Mecke; Melzer; Schlagden- hauffen. Glycerin. Barbsche; Boettger (sugar); Bougault (arsenic); Deane; Deniges; Donath-Mayrhof er ; Fol; Gruenhut; Hager; Reichl; Ritsert ; Senier ; Siebold (arsenic); Udransky-Baumann.' In FLUID EXTRACTS: Linde. In URINE : Baumann; Luch- singer. Glycerin, Acidulated. Squire. Glycerin and Gum. Faris; Shimer; Squire. Glycerin Gelatin. Kleb. Glycerin Hematoxylin. Renaut. Glycerin Jelly. Beale ; Brandt; Kaiser; Kleb; Lawrence; Seaman; Squire. Glycerin Mass. CARMINE : Beale. PRUSSIAN-BLUE: Beale. INDEX OF SUBJECTS. 359 Glycerin Medium. Haentsch; Jaeger. Glycerin Mixture. Calberla; Lee. Glycerin Mountant, Alkaline. Kirkby. Glycerin Mounts, Turpentine Cement for closing. Csokor (Czoker). Glycerin Preservative. Flemming. Glychemalum. Mayer. Glycocoll. Horsford. Glyconuric Acid. Bial. Glycotannoids. Kunz-Krause ; Liebermann. Gold. Cohnheim; Darton; Kern. In SILVER NITRATE: Schut- tle worth. Gold and Sublimate Stain. Ziehen. Gold and Iron Method. Upson. Gold and Vanadium Method. Upson. Gold Chloride. Branson. Gold Method. Henocque; Kolossow; Lowit; Manfredi; Mitro- phanow; Nesteroff sky ; Upson; Viallanes. Golds Stain. Bastian; Hoyer; Underwood. Gonococcus Stain. Neisser ; Pick ; Schiitz ; Steinschneider- Galewski. Green Injection Mass. Thiersch. Guaiac Resin. Hirschsohn (rosin). Guaiacol. rAdrian; Fonzes-Diacon ; Vreven. Guanidine Salts. Schulze. Guanine. Capranika. Gum and Glycerin. Squire. JELLY: Shimer. MEDIUM: Lang- erhan. Gurjun Balsam. Flueckiger; Hirschsohn. In COPAIVA: Enell; Hager; Hirschsohn. In URINE: Nobel. Halogens. B eilst ein . Hardening Fluids. Betz; Blum; Bunger; Carnoy; Erlicki; Flemming; Gilson; Goette; Johnson; Mueller; Perenyi; Prit- chard; Souza, de-. Hardening Methods. Lewis (brain) ; Whitman. Hemacalcium. Mayer. Hemalum, Acid. Mayer. Hemapheinic Urine. Munk. 360 INDEX OF SUBJECTS. Hematein. CARMINE-!NDIGO: Mayer. SOLUTION: Hansen. STAIN: Rawit. Hematophyrin. Salkowsky. Hematoxylin. Boehmer; Cole; Delafield; Hamilton; Heiden- hain; Kleinenberg; Maschke; Weigert. ACID: Butschli; Ehr- , lich. AMMONIATED: Ehrlich. BERLIN-BLUE REGENERATION: Weigert. METHOD: Pal. STAIN: Apathy Foa; Grenadier; Pal; Squire; Unna; Wolter (nerve). Hematoxylin-Copper. Benda. Hematoxylin-Eosine. Cole; Everard-Demoor-Massart; Hick- son; List; Massart; Renaut. Hematoxylin- Glycerin. Renaut. Hematoxylin- Iron. Benda; Butchli; Heidenhain. Hemin Crystals. SOLUTION FOR PREPARING: Melasse, Hemoglobin. Heller; Kobert. In URINE: Mahomed; Steven- son. Heroin* Goldmann; Kobert. Hemin Crystals (preparing). Malassez. Heroin. Kobert. Hetero-Albumose in Urine. Tyson. Heteroxanthin. Salomon. Hippuric Acid. Luecke; Phipson. Horse Meat. Braeutigam-Edelmann. Hydriodic Acid in Urine. Scivoletto. Hydrobromic Acid. Villiers-Fayolle. Hydrocarbons. Fritsche. Hydrochloric Acid. Boas; Leewenthal-Lenssen ; Loewenthal; Oster (arsenic); Reale; Villiers-Fayolle; Ziegler. In GASTRIC JUICE: Contejean; Ewald; Guenzburg; Kost; Luttke; Maly; Miller, von-; Mohr; Rabuteau; Riegel; Schuchardt; Siringo; Szabo; Toepfer; Uffelmann; Van der Velden; Velden; Winkler. Hydrochloric- Acid Carmine. Grenacher. Hydrocyanic Acid. Almen; Barry; Barfoed; Carey Lea; Deniges; Froehde; Hlaziwetz; Ottner; Lassaigne; Liebig; Pagenstecher ; Payer; Schoenbein; Schoenbein-Pagenstecher ; Vortmann. In AMYL NITRITE: Hager. Hydrogen Dioxide. Bach; Barralet; Boettger; Deniges; Kass- ner ; Schoenbein ; Schoenn ; Struve ; Traub ; Weltzien ; Wurster. Hydrogen Phosphide. Scherer. INDEX OF SUBJECTS. 3 61 Hydrogen Sulphide. Fischer; Ganassini; Merget. In URINE: Mueller. Hydrolysis of Butter Fat. Rideal. Hydroquinone. Baumann-Preusse. In URINE : Neubauer. Hyoscyamine. Gerrard. Hypochlorous Acid. Kolter. Hypodermoclysis, Solution for. Hayem. Hyposulphites. Alvarez-Jean; Carey Lea; Haugk. Hypoxan thine. Kossel. Illuminating Gas. Merget; Wartha (sulphur). In WATER: Himly. Imbedding. MASS: Brunotti; Fischer; Kadyi; Poelzam; Strieker; Viallanes. METHOD: Butchli; Duval; Ehrenbaum; Gilson; Ide; Joliet; Kultschitzky ; Lee; Ryder. SOLUTION: Tapping. Impregnation Method. Altmann. METHYLENE-BLUE: Dogiel. PRUSSIAN-BLUE: Leber. SILVER: Tartuferi. Impregnation Mixture, Mercuric. Cox. Indican. In PLANTS: Molisch. In URINE: Carter; Hammar- sten. Heller; Jaffe; Klett; Loubian; MacMunn; Obermayer; Weber; Weil-Gilbert. Indicators. Autenrieth; Boettger; Bolton; Borntraeger; Cris- mer; Dechan; Degener; Engel-Ville; Fischer-Phillip; Fittig; Formanek; Frebault; Henry, de-; Gawalowski; Hoffmann; Kruger; Lachaux; Lehmann-Petri; Luck; Lunge; Lux; Marsh; Maschke; Miller; Oser-Kalmann; Pellagri; Richter; Riegel; Riegler; Schaal; Schlickum; Simon; Spiegel; Stevenin; Storch; Von Duyck; Von Muller; Weiske; Weselsky; Wolff; Zaloziecki. Indigo-Carmine with Indigo or Hematein. Mayer. Indigo-Carmine and Aniline Blue. Maschold. Indigo-Carmine, Oxalic- Acid. Thiersch. Indigo-Red in Urine. Rosenbach. Indol. Bayer; Guezda; Nencki; Salkowski. In BACTERIAL CULTURES : Kitasato-Salkowski. Indulin Stain. Calberla. Inflammable Gas. Clowes. Infusoria. FIXING: Blanc. METHOD: Entz. QUIETING: Eis- mond. 362 INDEX OF SUBJECTS. Injection Fluid. CARMINE: Emery. RED: Bruecke. Injection Mass. ACACIA: Bjeloussow. ASPHALT: Budge. BERLIN-BLUE: Bruecke; Mayer; Mueller. CARMINE: Joseph; Thiersch; Ville. GREEN: Thiersch. IODINE: Lugol. LEAD- CHROMATE: Thiersch. PRUSSIAN-BLUE: Thiersch. SHELLAC:. Hoyer. Ink Injection. Taguchi. Inorganic Acids. Geoghan. Inosite. Scherer; Seidel. In URINE: Gallois. Invert Stain. Rawitz. lodates. Corne. In IODIDES: Pollacci; Schering. lodic Acid. Biltz; Reichardt. In NITRIC ACID: Hager; Hilger. Iodides. Hempel; Jones; Pollacci (iodates); Schering (iodates). In SALIVA: Bourget. In URINE: Bourget. Iodine. Alf raise ; Carey Lea; Castle; Chatin Gaultier de Claubry ; Filhol; Grange; Henry; Henry- Humbert; Jacquemin; Koetts- torfer; Laronde; Lassaigne; Maier; Marchand; Overbeck; Peloggio; Price; Rabourdin; Reynoso; Stanford; Tessier; Thomson; Tilden; Vitali; Wachhausen; Winkler. In BRO- MINE: Jorissen. In COMPOUNDS: Thorns. In URINE: Har- nack; Jolles; Sandlund; Seivolete. Iodine Fixing. Overton. Iodine Number. Huebl. Iodine-Potassium Iodide. Kuehne. Iodine Solution. Gram; Huebl- Waller ; Wagner- Fresenius. Iodine Test-paper. Sabrazes-Deniges. Iodized Serum. Frey; Ranvier; Schultze. lodoform. Deniges; Greshoff; Guyot; Lustgarten. Iron. Andreasch; Bellamy; Deniges; Fairbank (phosphorus); Fuge; Lasaulx; Wildenstein. In COPPER SULPHATE: Griggi. In FERRUGINOUS NUCLEINS and NUCLEO-ALBUMINS: Just. In TISSUES: Tizzoni. Iron Carmine. Zacharias. Iron Citrate. Griggi. Iron-Hematoxylin. Benda; Butschli; Heidenhain. Iron Isopyrotritarate. Simon. Iron Method. Upson. Iron-Persulphate Solution. Monsel. Iron-Pyrogallate Stain. Roosevelt. INDEX OF SUBJECTS. 36$ Isatropyl Cocaine. MacLagan. Iso-Eugenol. Chapman. Iso-Saffrol. Chapman. Jalap. Buchner. Kairin in Urine. Petri; Renzone. Kermes Coloring in Wine. Heise; Hilger-Mai. " Kernschwarz " Stain. Lee. Ketones. Bela-von Bitto; Fischer; Villiers-Fayolle. Ketoses. Sieben. Kinovic Acid. Winkler. Kousso Flowers. Kuhl. Lactic Acid. Boas; Uffelmann. Lactose. Rosenbach. Lanolin . Lieberm ann . Lard Oil, Cottonseed in. Conroy; Gantter. Lead. Blyth; Bobierre; Fordos. In TINFOIL: Kopp. Ins URINE: Abram; Hahnemann. Lead Chromate. GELATIN MASS: Hoyer. INJECTION MASS: Thiersch. Lead Ore. Krutwig (silver). Leguminous Flour in Wheat Flour. Donny. Lemon- Juice Method. Ranvier. Lemon Oil. Schimmel. Leprosy Bacillus Stain. Bates; Baumgarten; Luebimoff; Lust- garten; Lutz-Unna; Unna. Leucine. Hofmeister; Scherer. In URINE: Frerich. Levulose. Ihl-Pechmann ; Seliwanoff . Lignin. Hegler; Hoehnel, von-; Maule; Niggl; Wiesner. Lilac Borax Carmine. Thiersch. Lemon Juice. Warington (citric acid). Lime Juice. Warington (citric acid). Limonene. Burgess. Linalol. Burgess. Linalyl Acetate. Burgess. Linen Fibers. Boettger. Linseed Oil. Morrell. In OLIVE OIL: Millian. Lithium Carbonate. Symons (sodium). Lithium Carmine. Orth. Lubricants from Petroleum, Tarry Constituents of. Holde. 364 INDEX OF SUBJECTS. Lubricating Oils, Soap in. Schweitzer. Mace, Bombay. Boehm; Busse; Hefelmann; Waage. Maceration Media. Bela-Haller; Borme; Calberla; Hertwig; Kuehne; Landois; Lavdowsky; Loeffler; Mobin; Schultze; Soulier; Trenkmann. Maceration Method. Minot; Mitrophanow. Magenta Stain. Gibbes. Magnesia. Sehaffgott. Magnesia Mixture. Gilbert. Magnesium. Deniges . Magnesium Salts. Lepel; Schlagdenhauffen. Malic Acid. Papasogli-Poli. Manganese. Boettger; Campani; Davy; Deniges. In ZINC: Gayard; Guyard. Manganese-Chloride Solution. Pict et . Margarin. Partheil. In BUTTER: Drouot; Soxhlet. Martius Yellow. In PASTRY: Schaefer. In URINE: Vitali. " Mastzellen." Ehrlich. Media. CULTURE: Pasteur. DISSOCIATION: Stirling. MACER- ATION: Lavdowsky; Loeffler; Mobin. MOUNTING: Apathy; Brady; Brun; Deane; Fabre-Domergue; Farrant; Gannal; Geoffrey ; Haentsch ; Heurck, van- ; Hoyer ; Jaeger ; Langerhan ; Lavdowsky ; Lee ; Noll ; Ripart ; Schultze ; Squire ; Stephenson ; Suchannek; Vosseler. NUTRIENT: Sachs. PRESERVATIVE: Barff. TYPHOID BACILLI: Stoddart. Melanin. Pollak. In URINE: Eiselt; Jaksch, von-; Thormaeh- len; Zeller. Menthol. Eykmann (thymol). In OIL PEPPERMINT: Schimmel. Mercuric Impregnation Mixture. Cox. Mercuro- Nitric Mixture. Gilson. Mercury. Eschka; Fuerbringer; Gmelin-Smithson; Merget; Morgan; Teubner. In ATMOSPHERE: Gaglio. In URINE: Jolles; Ludwig. Mesityl-quinone. Fittig. Metalbumin. Hammarsten. Metagelatin Vehicle. Fol. Metallic Salts. Schmid. Metals. Cazeneuve; Deniges. Meta-Vanadates. Werther. INDEX OF SUBJECTS. 3 6 S, Methacetin. Moers. Methane. Merget. Methyl Alcohol. Cazeneuve-Cotton ; Jacquemart ; Mulliken-. Scudder. In ALCOHOL: Langbeck; Rice-Bardy. Methyl-Green Eosine Stain. Calberla; List. Methyl Mixture. Schiefferdecker. Methyl Orange. Lunge; Miller. Methyl Salicylates, natural and artificial. Adrian. Methyl- Violet Solution. Koch; Kuehne. Methyl-Violet Stain. Orth. Methylene Blue. METHOD: Apathy; Bethe; Dogiel; Kuehne ; Nissl; Rouget. SOLUTION: Koch: Kuehne; Loeffler. STAIN: Dogiel; Koch; Parker. Methylene-Blue Eosine Stain. Chenzinsky; Pianese. Methylene-Blue Borax. Sahli. Michrochemical Reagent. Lutz. Micro-Preservative Solution. Keiser. Micro-Sections. HARDENING FLUID for: Bunger. STAINS for: Genfer; Gram-Gunther; Hanstein. Microscopical Examination of Blood. Hayem. Migranin. Str obel . Milk. Adams (fat); Carcano (boiled and unboiled); Hehner (formaldehyde); Hosaeus (borax; sodium bicarbonate); Leff- mann-Beam (fat); Lythgoe (aniline orange); Medicus (sali- cylic acid); Schaeffer (boiled and unboiled); Vaudin; Werner- Schmidt (fat). Milk Sugar. Conrady; Rubner. Mineral Acids. Bergman; Flueckiger; Hager; Huber; Hume; Kieffer ; Mohr ; Rheoch ; Spence-Esilmann. In ORGANIC ACIDS : Nickel. In VINEGAR: Ashby; Chiappe; Griggi; Hehner; Jorissen; Mallet; Strom; Wharton; Witz. Mineral Oils. Lux; Wiederhold. Mineral Substances in Flour. Himly. Mineral Waters, Organic Matter in. Garrigou. Minerals. Klein; Thoulet. Moisture. Merget. Molybdenum. Maschke. Molybdic Acid. Braun; Kobell; Schoenn; Siewert. Monatomic Alcohols. Bitto. 366 INDEX OF SUBJECTS. Morphine. Fairthorne; Grove; Horsley; Husemann; Jassoy; Jorissen; Kalkbrenner; Kieffer; Kobert; Kotzebue; Lamal; Lefort; Lindo; Loof; Marquis; Mecke; Melzer; Nadler; Otto; Robin; Robinet; Robiquet; Schneider; Selmi; Serullas; Siebold; Tattersall; Thomas; Vitali; Wangerin; Wellcome; Wender; Weppen; Woolsey. In QUININE SULPHATE: Hesse. In URINE: Landsberg-Wislicenus. Motor Activity of Stomach. Siewer. Mounting Medium. Apathy; Beale; Gannal; Geoffrey; Heurck, van-; Hoyer; Ripart; Schultze; Stephenson; Suchannek; Weigert. Mounting Process, Gelatin. Alleger. Mounting, Slow or Exposure. Cole. Mucicarmine for Staining Mucus. Mayer. Mucihematein for Staining Mucus. Mayer. Mucilage, Quince. Born-Wieger. Mucin in Urine. Salkowsky-Leubes. Musk. B erzelius . Mustard, Turmeric in. Wilder. Mustard Oil, Carbon Bisulphide in. Luck. Myrrh. Bonastre; Righini. BISABOL and HERABOL: Tucholka. Naphtalin. Edlefsen; Penzoldt; Thorns. Naphtol. ALPHA: Aymonier; Leger. BETA: Leger. Naphtols. Flueckiger; Lustgarten; Richardson; Thorns; Wolf. Naphtol Yellow. In PASTRY: Schaefer. In URINE: Vitali. Narceine. Arnold; Dragendorff; Mecke; Melzer; Stein; Vogel. Narcotine. Couerbe; Elias; Mecke; Melzer; Robin. Narcotization. METHOD: Foettinger; Fol; Korotnoff; Reden- baugh; Tullberg; Verworn. SOLUTION: Bianco; Hofer. Nataloin. Histed. Natural Injections. Zellner. Nerve-Centre Stain. Adamkiewicz. Nerve Stain. Alt; Henle; Kaiser; Kultschitzky; Lewis, Bevan-; Magini; Mann; Nissl; Rehm; Sahli; Sankey; Schmans; Von Marchi; Wolter. Neuroglia Stain. Weigert. Neurological Method. Bellonci; Kallins. INDEX OF SUBJECTS. 3 6 7 ^Nickel. Braun; Deniges; Papasogli. Nicotine. Heut; Mecke; Melzer; Palm; Schindelmeiser; Wender. Nitrates. Allesandri-Guaceni ; Deniges ; Grimaux ; Jean- Alvarez ; Lindo; Spiegel. In WATER: Cazeneuve-Defournel. Nitric Acid. Allesandri-Guaceni; Altman; Austen-Chamber- lain; Bailey; Boettger; Bolas; Boussingalt; Broun; Desbassin; Hager (iodic acid); Hilger (iodic acid); Horsley; Kammerer; Kersting; Kopp; Lindo; Longi; Lunge-Lwoff; Martin; Nichol- son; Piccini; Reichardt; Richmond; Schmidt; Sprengel; Stein; Tassini-Piazza ; Uffelmann; Vogel. In URINE: Schoen- bein; Schulze; Weyl. Nitrites. Bujwid; Deniges; De venter; Fresenius; Green wait; Lindo; Pichard; Riegler; Sabatier; Schaefer. Nitrobenzene. Bechampo; Bourgoin; Brunner; Debrunner; Dragendorff; Jacquemin; Morpurgo. In ESSENTIAL OIL ALMOND: Hager; Henninger; Maisch; Pegna. Nitro-Glycerin. Mohr; Werber. Nitrogen. Donath; Kjeldahl; Knop. In URINE: Allen. Nitrogenous Compounds, Organic. Lassaigne. Nitrophenol. Langbeck. Nitroso Compounds. Liebermann. Nitrous Acid. Boettger; Chatard; Frankland; Fresenius; Griess; Griess-Ilosvay; Hager; Jorrisen; Kammerer; Kopp; Lunge-Lwoff; Meldola; Plugge; Rideal-Green ; Schoenbein; Schuyten; Trommsdorff; Wilson. In BLOOD: Bertoni-Ray- mondi. In URINE: Schoenbein. In WATER: Maschke. Nitrous Ether, Water in. Lloyd. Nucleo Albumins. Just (iron). In URINE: Reissner. Nutrient Medium. Sachs. Nux Vomica. Schlienkamp. ASSAY: Dunstan-Short. Oil, Almond, Expressed. Bieber. Oil, Almond, Essential, Nitrobenzene in. Hager; Henninger; Maisch; Pegna. Oil Anise. FREEZING MASS: Kuehne. IMBEDDING PROCESS: Moore. Oil Bergamot, Oil Turpentine in. Gulli. Oil Cacao. Filsinger. Oil Cajuput, Cineol in. Faulding. 368 INDEX OF SUBJECTS. Oil Cassia. Hirschsohn. Oil Castor. Bollet; Draper; Finkener; Di Vetere. In COPAIVA: Hager; Maupy. In CROTON OIL: Maupy. In OLIVE OIL: Leonard!. Oil Cedarwood. In SPEARMINT OIL: Kremers-Schreiner. Oil Clove, Phenol in. Flueckiger. Oil Copaiva. In URINE: Nobel. Oil, Coriander. Schimmel. Oil Cottonseed. Bechi; Deiss; Halphen; Hirschsohn; Labiche; Millian; Ruggieri-Tortelli ; Wolfbauer. In LARD: Conroy; Gantter. In OLIVE OIL: Brulle; Hauchecorne; Heydenreich. Oil Croton. Maisch; Maupy (castor oil). In TINCTURE IODINE: Durien. Oil Eucalyptus, Cineol in. Faulding. Oil, Fusel. Betelli; Vitali. Oil Gurjun. Flueckiger. In COPAIVA: Enell. Oil Lemon. Schimmel. Oil Linseed. Morrell. Oil Olive. Boudet; Bradford; Brulle (foreign oils); Buch- heister; Codina-Laenglin ; Conroy; Diesel; Hauchecorne (cot- tonseed oil); Kopp; Laillier; Leonardi (castor oil); Lipowitz; Marchand; Merz; Schneider (cruciferous oils); Wimmer; Zechini. Oil, Peach Kernel. Bieber. Oil Peanut. Renard; Souchere. Oil Peppermint. Arzberger; Flueckiger; Jehn; Schack; Schim- mel. Oil Rose. Ganswindt; Guibourt. Oil Rose-Geranium. Jaillard. Oil Rosin. Storch-Morawski. In OIL MIXTURES: Storch. Oil, Sandal. Hendrix. Oil, Sesame. Basoletto; Baudowin; Breinl; Bremer; Camoin; Carlinfanti; Fabris- Villa vecchia ; Flueckiger- Behren; Gassend; Lewin; Soltsiens; Tambon; Tocher. Oil Spearmint. Schreiner-Kremers. Oil Turpentine. Vogel. In OIL BERGAMOT: Gulli. Oil Valerian. Flueckiger. Oil Mixtures, Rosin Oil in. Storch. Oiled Wheat. Himly. INDEX OF SUBJECTS. 369 Oils. Cailletet (copper); Huebl; Jean; Maumene; Penot; Schoenvogel; Schramm; Wemince. CRUCIFEROUS: Grehant; Miahle. ESSENTIAL: Barbier (alcohol); Crismer (turpentine); Dragendorff (alcohol); Elram; Flueckiger; Forney (alcohol); Hager (alcohol; chloroform); Hoppe; Leonard! (alcohol); Leuch (Water); McClellan- Forney (alcohol; turpentine); Maier (turpentine); Maisch; OberdoerfTer (alcohol); Perrot; Puscher (alcohol); Redwood (alcohol); Stuart (alcohol): Sulzer (alcohol); Tuchen; Walz (fixed oils). FATTY: Barbot; Behrens; Bieber; Bourdat; Cailletet; Calvert; Crace-Calvert ; Glaessner; Hager; Heidenreich; Jacobsen; Livache; Massie; Merz; Nickles; Poutet; Roth; Royere, de la-. MINERAL: Wiederhold. ROSIN: Wiederhold. In COPAIVA: Gerber; Ha- ger; Hirschsohn; Muter; Lux. Olive Oil. Boudet; Bradford; Brulle (foreign oils); Buch- heister; Codina-Laenglin ; Conroy; Di Vetere (castor oil); Diessel; Hauchecorne (cottonseed oil); Heydenreich (cotton- seed oil); Kopp; Laillier; Leonardi (castor oil); Lipowitz; Marchand; Merz; Millian (linseed oil); Schneider (foreign oils); Wimmer; Zechini. One-Third Alcohol. Ranvier. Opium. Brissemoret (alkaloids of);Everitt; Merck; O'Shaugh- nessy; Southey. Orange Method. Flemming. Orcein Stain. Israel. Orchella Stain. Wedl. Organic Acids. Geogehan; Nickel (mineral acids); Pinerna. In PHENOL: Bachmeier. Organic Matter. Lassaigne. In WATER: Dupasquier ; Garrigou; Marchand. Orseille Stain. Wedl. Osmic Acid. METHOD: Azoulay; Bristol; Mann; Overton; Ranvier-Vignal. STAINS: Kolossow; Lee; Mahrenthal, von-; Pal-Exner. Ova, Examination Liquid for. Henking. Oxalic Acid. Salkowsky. SOLUTION: Boccardi. In URINE: Reoch. Oxalic-Acid Carmine. Thiersch. Oxalic-Acid Indigo-Carmine. Thiersch. 370 INDEX OF SUBJECTS. Oxygen Process. Tidy. Ozone. Boettger; Chlopin; Houzeau (test paper); Merget; Schoenbein (test paper); Wurster ("tetra" paper). Palladium-Iodide Stain. Paladino. Papaverine. Anderson; Mecke; Melzer; Tattersall; Wender. Paper. Dahlmann ; Friedlander (wood fibre) ; Geissler (albumin test-); Griess (test-); Herzberg; Houzeau (ozone test-); Wolesky (wood fibre). Paracarmine. Mayer. Para-Amidophenetol in Phenacetin. Reuter. Para-cresol. Jaksch, Von-. Paraffin. Spee, Graf. MASS: Van Walsem. In WAX: Est- court-Parry; Landott. Paranitrophenol. Spiegel. Paraoxyphenylacetic Acid. Millon. Paratoliudine. Lauth ; Rosenstiehl. Paraxanthin . Salomon . Peanut Oil. Renard; Souchere. Peach-Kernel Oil. Bieber. Peas, Preserved, Copper in. Nikitin. Pentose. Bial; Tollens. Ptlagic Animals, fixing delicate. Bedot. Peppermint Oil. Arzberger; Flueckiger; Jehn; Schack. Pepsin. Langley. Pepsinogen. L angley . Peptones. Bogomolow-Wassilieff ; Devoto ; Gorup-Besanez ; Hofmeister; Riegler. In URINE: Jaworowski; Martin; Posner; Ralfe; Randolph; Salkowsky. Permanganate Method. Henneguy. Permanganate Solutions, Standardizing. Stolba. Peronin. Robert . Peroxides. Dudderidge. Peru Balsam. Gawalowski (alcohol); Gehe; Hager (benzoin); Hirschsohn. Petrolatum, Animal and Vegetable Fats in. Crouzel-Dupin. Petroleum. Bird; Holde. Phenacetin. Autenrieth-Hinsberg; Gigli; Hirschsohn (acetani- lid); Moers; Reuter (para-amidophenetol) ; Ritsert; Schroeder (acetanilid) ; Strobel. INDEX OF SUBJECTS. 371 Phenacetolin. Degener ; Lunge. Phenetidin in Urine. Edlefsen. Phenol. Allen; Almen; Bachmeier (organic acids); Berthelot; Clarke; Cotton; Davy; Deville; Eykmann; Fiora; Flueckiger; Frisch; Fresenius; Hirsch; Hoffmann; Hoppe-Seyler ; Jacque- min; Klunge; Landolt; Lex; Liebermann; Lindo; Maseau; Mene; Millon; Morson; Neubauer; Penzoldt-Fischer; Plugge; Pollacci; Salkowsky. In URINE: Dragendorff. Phenols. Candussio; Chapman; Defacqz; Hoffmann; Lowe; Orlow; Thorns. Phenolphtalein. Luck. Phloroglucin. Thorns ; Weselsky . MIXTURE : Ferreri. Phosphoric Acid. Bunsen; Fourcroy; Gilbert; Merz; Pagel; Ross; Selmi; Svanberg. Phosphorus. Fresenius- Neubauer; Hager; Mitscherlich ; Mu- kerji; Scherer; Schiff; Schoenn; Woehler. In IRON: Fairbank. In ORGANIC MATTER: Lipowitz. In PHOSPHORIC ACID: Pagel. In TISSUES: Bastelaer; Dusart-Blondlot. Phosphorus Hydride. Hager. Phosphotungstic Acid for Alkaloids. Schering. Phyllocyanin. Pellagri. Physostigmine. Mecke; Petti. Picric Acid. Brunner; Pohl. In BEER: Rupeau. Picric Alcohol. Gage. Picro-Carmine. Ranvier; Squire; Vignal-Ranvier; Weigert. METHOD: Cole. Picro-Chromic Acid. METHOD: Fol. SOLUTION: Haensel. Picro-Hydrochloric Acid. Mayer. Picro-Nigrosin Stain. Freeborn; Martinotti. Picro-Nitric Acid. Mayer. Picro-Osmic Acid. Vom Rath. Picro-Platinic Mixture. Vom Rath. Picro-Platinic-Osmic Mixture. Vom Rath. Picro-Sublimate Mixture. Rabl; Vom Rath. Picro-Sublimate-Osmic Mixture. Vom Rath. Picro-Sulphuric Acid. Kleinenberg; Mayer. Picro-tannin Mixtures. Mann. Picrotoxin. Becker; Duflos; Mecke; Melzer; Minovici; Oglialoro; Otto; Palm. 372 INDEX OF SUBJECTS. Pigments, Biliary. Barral; Bartley; Basham; Bruecke; Casali; Capranika; Dumontpallier ; Dumontpallier-Trousseau ; Dra- gendorff; Deubner; Fleischl; Gerard; Gerhardt; Heller; Hilger; Hoppe-Seyler ; Huppert; Jolles; Krehbiel; Lewin; Marechal; Neukomm; Noel; Paul; Penzoldt; Riegler; Rosenbach; Rosin; Schwanda; Smith; Triollet; Tiedemann-Gmelin ; Ultzmann; Vitali; Yvon. Pigments, Wine. Nessler. i Pilocarpine. Helch; Lenz; Nagelvoort. Plasma Cells, Staining Method for. Bergonzini. Platino-Aceto-Osmic Mixture. Hermann. Platino-Sublimate Mixture. Rabl. Platinum. Fischer. FIXING SOLUTION: Rabl. HARDENING- MIXTURE: Johnson. Platinum Chloride. Merkel. Podophyllum Resin. Millard. Polka-Paper. Schott . Pomegranate-Root Bark. Kuhl. Potash Preparations, Preservative for. Gage. Potassa Solution. Moleschott. Potassio-Ferric Tartrate. Griggi. Potassio-Mercuric Iodide Solution. Masin; Mayer. Potassium. Erdmann; Konick, de-; Woerner. ACETATE (so- lution): Squire. BICHROMATE: Donath. -CHROMATE: Do- nath; Ludwig. CYANATE: Schneider. IODIDE: Lepage. PERMANGANATE (solution): Mohr. PICRAMATE: Frebault. PLATINIC-CHLORIDE (reagent): Schwarzenbach-Delff. SALTS: Campani; Gurtman; Mohr; Stolba. In URINE: Heintz; Salkowsky. Precipitates, Soluble. Borodin. Preservative Fluid. Barff; Flemming; Gage; Gilson; Glage; Goadby (or Godbay); Harting; Keiser; Pacini; Pick; Ripart- Pettit; Thwaite; Wickersheimer. Primary Amines. Hoffmann. Proteids. Bruecke; Mandel; Michailow; Petri; Piotrowski; Rideal-Stewart. Protein. Ritthausen ; Sonnenschein. Proximate Principles. Johannson. INDEX OF SUBJECTS. 373 Prussian-Blue. GLYCERIN MASS: Beale; Robins. INJECTION: Leber; Ranvier; Thiersch. Ptomaines. Brouardel-Boutmy ; Trotarelli. Pus. Day. In URINE: Donne. Pyridine. Anderson. For HARDENING: Souza, de-. Pyrocatechin. Brieger; Mueller- Ebstein. In URINE: Mueller- Ebstein; Neubauer. Pyrogallol. Griggi; Mathieu-Plessy ; Watson. Stain: Lee; Mah- renthal, von-. Pyroligneous Matter in Acetic Acid. Lightfoot. Pyrophosphoric Acid in Urine. Joly-Pacquelin. Quinamine . Oudemans . Quince Mucilage. Born-Wieger. Quinidine. Hesse ; Hirschsohn. Quinine. Andre; Blaise; Creuse (salicin); DeVrij; Flueckiger; Glenard; Hager; Heyninger, van-; Hesse (allied alkaloids); Kerner; Kletzinski; Kubli; Leers; Leube; Liebig; Maisch; Mecke; Pelletier; Robin; Schwabe; Vogel; Vrij, de-; Wender; Zeller. In URINE: Binz; Kerner; Vitali. SULPHATE: Hesse (morphine); Paul (cinchonidine) ; Schaefer. Quinoline. Anderson. Raspberry Syrup, Cherry Syrup in. Windisch. Reagent. Faktor; White. Red Injection Fluid. Bruecke. Red Wine, Coloring Matters of. Boettger. Reduced Iron. Fuge. Reducing Solution. Pritchard. Regenerating Osmic-Acid Solutions. Bristol. Regenerating Weigert's Hematoxylin. Berlinerblau. Rennet, Zymogen of. Klemperer. Resazurin. Crismer. Resin in Wax. Donath; Donath-Schmidt ; Estcourt-Parry. Resin. Elram; Hehn; Unverdorben-Franchimont ; Storch-Mo- rawski. In WAX: Schmidt- Donath. PODOPHYLLUM: Millard. See also ROSIN. Resorcin. Bodde; Ferraro; Thorns. Rhubarb. Maisch (turmeric); Opwyrda (turmeric); Wilder (turmeric). In URINE: Proksch. Rose Oil. Ganswindt; Guibourt. 374 INDEX OF SUBJECTS. Rose-Geranium Oil. Jaillard. Rosin. In BALSAM TOLU: Hirschsohn. In GUAIAC RESIN: Hirschsohn. Rosin Oil. Storch-Morawski ; Wiederhold. In OIL MIXTURES: Storch. Rotifiers. Rousselet . Rubidium. Erdmann. Rum, Genuine. Wiederholt. Rye-Flour, Ergot in. Boettger. Rye Flour. Wittmack. Sabadilline. Wender. Saccharin. Boernstein; Bornstein; Hairs; Kayser; Leys; Linde- mann-Motten ; Lindo; Remsen; Schmidt; Spica. Saffrol. Chapman. Safranine. Boettger; Martinotti-Resegotti. SOLUTION: Bates; Flemming. STAIN: Babes; Foa; Pfitzner; Podwysotzki; Rese- gotti-Martinotti ; Szobolew; Zwaardemaker. Salicin. Robin. In QUININE: Creuse. Salicylic Acid. Almen; Hager; Jorissen; Lindemann-Motten ; Millon; Phipson; Ridenour; Schulze; Thorns. In MILK: Medicus. In URINE : Robinet ; Siebold-Bradbury. In WINE : Spicea. Salicylic Vinegar. Meyer. Salicylic Vinegar and Gum Medium. Noll. Salipyrine. Strobel . Saliva, Iodides in. Bourget. Salol. Strobel. Salophen. Goldmann ; Reutmann. Salt Solution. Carnoy. Sandal Oil. Hendrix. Sandarac Medium. Lavdowsky. Sanguinarine. Orlow-Horst. Santonica. Astolfi. Santonin. Ferraro; Hager; Lindo; Pain; Schermer; Smith. In URINE: Crouzel; Hoppe-Seyler. Sausage, Decomposed. Eber. Scammony. Buchner. Scheele's-Green Coloring Mass. Robins. Serial Sections. Poli; Rabl; Schaellibaum. INDEX OF SUBJECTS. 375 Serum. ARTIFICIAL: Kronecker; Frey (iodized). CHOLERA REACTION: Pfeiffer. IODIZED: Ranvier. Serum Paper. Richardson. Sesame Oil. Basoletto; Baudouin; Bremer; Breinl; Camoin; Carlinfanti; Fabris-Villavecchia ; Flueckiger-Behren ; Gassend; Lewin; Soltsiens; Tambon. In OTHER OILS: Tocher. Sesquiterpenes. Wallach . Shellac Fixative. Giesbrecht; Mayer. Shellac Injection Mass. Hoyer. Shellac Method for Hard, Chitinous Objects. Hyatt. Shikimi Fruit in Star Anise. Lenz. Silicic Acid. Barfoed. Silk. Hoehnel, Von-; Jacquemin; Lidof; Liebermann; Peltier. Silver. In LEAD ORE: Krutwig. STAIN: Alferow; Hoyer; Mueller; Jakimovitch; Oppitz; Renaut; Robinski; Rouget; Sattler; Tartuferi; Tourneux- Hermann. Silver Bromide, Chloride, and Iodide. Volhard. Silver Nitrate. GELATIN MASS: Hoyer. INJECTION: Ranvier. SOLUTION: Wanklyn. Skat ol. Ciamician- M agn anini . Slide Cleaning Solution. Fol; Hanaman; James; Knauer; Nias. Smegma Bacillus Stain. Housell. Soap. IMBEDDING MASS: Fischer. SOLUTION: Clark; Wanklyn. In LUBRICATING OILS: Schweitzer. Soda Preparations, Preservative for. Gage. Soda Solution. Moleschott. Sodium Bicarbonate in Milk. Hosaeus. Sodium Carbonate. Biltz. Sodium Chloride and Alcohol. Moleschott-Piso-Borme. Sodium-Hypochlorite Solution. Labarraque ; Noll. Sodium in Lithium Carbonate. Symons. Sodium Picramate. Frebault. Sodium Salts. Hager; Streng. Soil, Excrement in. Finkelbury. Solanine. Bach; Bauer; Clarus; Dragendorff ; Helwig; Mecke. Soluble Precipitates. Borodin. Solution. Hayem (hypodermoclysis) ; Huebl; Loeffler; Melassez: (for hemin crystals); Prollius. ALKALINE-PERMANGANATE: Wanklyn. AMMONIUM-CHLORIDE: Wanklyn. ANILINE: 376 INDEX OF SUBJECTS. Kuehne. CARMINE: Hamann. CARMINE-ALUM: Grenacher. CELLOIDIN: Busse; Elsching. CHLORAL-HYDRATE: Munson. CULTURE: Cohn; Zune. DAMMAR: Pfitzner. DECALCIFICA- TION: Haug. DIPHENYLAMINE-SULPHATE: Kopp; Pollet. FIXING: Altmann; Carter; Eisig; Flemming; Fol; Hayem; Kollmann; Kultchitzky; Zencker. FORMALDEHYDE: Her- mann; Lavdowsky; Lee. FORMIC-ACID: Boccardi. FUCH- SINE: Frey. GENTIAN- VIOLET: Ehrlich. HARDENING: Blum; Carnoy; Flemming; Remak. HEMATEIN: Hansen. IODINE: Gram; Huebl- Waller. IODINE-POTASSIUM-!ODIDE: Wagner- Fresenius. IRON-SUB SULPHATE: Monsel. MAGNESIUM-HY- POCHLORITE: Ramsay. MANGANESE-CHLORIDE: Pictet. ME- THYL-VIOLET: Koch; Kuehne. METHYLENE-BLUE: Koch. MICRO-PRESERVATIVE: Keiser. NARCOTIZATION: Hofer. Os- Mic-Acio: Bristol. OXALIC ACID.: Boccardi. PICRO-CHROMIC ACID: Haensel. PLATINIC-CHLORIDE: Rabl. POTASSA: Mole- schott. POTASSIO-MERCURIC IODIDE: Masin; Mayer. PO- TASSIUM-ACETATE : Squire. POTASSIUM-PERMANGANATE : Mohr. PRESERVATIVE: Glage; Pick. SAFFRANINE: Bates; Flemming. SALT: Carnoy. SILVER-NITRATE: Wanklyn. SLIDE-CLEANING: Fol; Hanaman. SOAP: Clark; Wanklyn. SODA: Moleschott. SODIUM-CHLORIDE-ALCOHOL: Piso- Borme - Moleschott. SODIUM - HYPOCHLORITE : Labarraque ; Noll. STARCH: Zulkowsky. SUBLIMATE: Frenzel; Heiden- hain; Keiser; Lee. TANNIN: Carnoy. TURPENTINE: Huehne- feld. WASHING-SODA : Nias. Sparteine . M arque . Spinal Chord Stain. Kaiser. Spirit Nitrous Ether. Allen. Spore Stain. Ernst; Neisser; Neisser-Bienstock. Stain. ACTINOMYCOSIS: Weigert. ALUM-PICRO-CARMINE: Le- gal. AMMONIA-CARMINE: Hartig. ANILINE: Hanstein. BACTERIA: Blanchard; Ehrlich; Ermengen, van-; Ernst; Fischer; Gram; Gunther; Koch; Kuehne; Loeffler; Lugol; Schutz-Weigert ; Weigert. BENZOAZURIN: Martin. BIL- BERRY-JUICE: Lavdowsky. BLEU-DE-LYON: Baumgarten. BLOOD: Ganther; Kastenbine; Moore; Rosenbach; Toison; Willeband; Wissowsky. BLUE: Hoffmann. BONE: Busch. BRAIN: Weigert. BISMARCK-BROWN: Kaiser; Maysel. CELL- INDEX OF SUBJECTS. 377 NUCLEUS: Grenadier. CHITIN: Bethe. CHOLERA BACILLUS: Kuehne. COMMA-BACILLUS: Bates. CILIA: Ermengen, von-. COCHINEAL: Mayer. DAHLIA: Ehrlich. DOUBLE: Benda; Gibbes; Kossinski; Seller. EMBRYO: Allen. EPITHELIA: Jakobsohn. FERRIC-CHLORIDE: Fol; Hoggan. FIBRIN: Wei- gert. FLAGELLA: Bunge; Crookshank; Hessert; Koch; Loef- fler; Lutesch; Nicholle-Morax ; Sclavo; Trenckmann; Von Ermengen. FORMALDEHYDE: Ohlmacher. FUCHSINE: Nissl. FUCHSINE-METHYLENE BLUE: Baumgarten. GENTIAN- 'S VIOLET: Ehrlich; Nissen. GOLD: Bastian; Hoyer; Under- wood. GOLD-SUBLIMATE : Ziehen. GONOCOCCI : Pick. HEMATEIN: Rawitz. HEMATOXYLIN: Apathy; Foa; Gre- nacher; Pal; Squire; Unna; Wolter. HEMATOXYLIN-EOSINE: List. INDULINE : Calberla. IRON-PYROGALLATE : Roose- velt. KERNSCHWARZ : Lee. LEPROSY-BACILLI : Bates. MAGENTA: Gibbes. METHOD: Biondi; Berkley; Boettger; Brosicke; Ehrlich; Ehrlich-Biondi ; Friedlander; Gaffky; Giacomi; Graser; Hermann-Boettger; Koch-Ehrlich; Lanz; Rabl; Paneth; Sterling. METHYL-GREEN-EOSINE: List. METHYLENE-BLUE: Dogiel; Koch. METHYLENE-BLUE- EOSINE: Pianese. MICRO-SECTION: Genfer; Gram-Gunther. MUCICARMINE: Mayer. MUCOHEMATEIN: Mayer. NERVE: Alt; Henle; Kaiser; Kultschitzky ; Lewis; Magini; Rehm; Sahli; Sankey; Schmans; Von Marchi. NEUROGLIA: Weigert. ORCEIN: Israel. ORCHELLA: Wedl. ORSEILLE: Wedl. OSMIUM: Kolossow; Lee; Mahrenthal, von-. PAL- LADIUM-IODIDE: Paladine. PICRO-NIGROSINE: Martinotti. PLASMA-CELL: Berganzini. PYROGALLOL: Lee; Mahrenthal, von-. SAFRANINE: Babes; Foa; Pfitzner; Podwyssotzki ; Szobolew; Zwaardemaker. SILVER: Alferow; Hoyer; Mueller; Oppitz; Robinski; Rouget; Sattler; Tourneux- Hermann. SMOOTH-MUSCLE: Unna. SPINAL-CHORD: Kaiser. SPORE- BEARING BACILLI: Neisser. SYPHILIS BACILLI: Doutrelepont- Schiitz; Giacomi; Lewy; Lustgarten. TUBERCLE BACILLI: Balmer-Fraenzel; Benysek; Gabbet; Gibbs; Koch; Pewsner- Nastinkow ; Schultz ; Ziehl-Neelsen. TYPHUS-BACILLI : Kuehne. VANADIUM : Wolter. Stannous Chloride. Rogers. Star Anise, Shikimi Fruit in. Lenz. 378 INDEX OF SUBJECTS. Starch. Boettger (flour). In CHOCOLATE: Wittstein. In* DRUGS and FOOD PRODUCTS: Lagerheim. SOLUTION: Zulkow- sky. Stearin in Wax. Escourt-Parry; Geith. Strychnine. Allen; Brieger; Davy; Dragendorff; Dunstan- Short; Hagen; Hager; Horsley; Landerer; Lefort; Lyon (mix- ture for extracting); Mack; Mandelin; Marchand; Mecke; Melzer; Orlow-Horst; Otto; Strychnine; Selmi; Slater; Taf el; Thomas; Vitali; Wender. In URINE: Schultzen. Sublimate. METHOD: Golgi. SOLUTION: Fraenzel; Heidenhain; Keiser; Lee; Van Beneden. Sublimate and Gold Stain. Ziehen. Succinic Acid. Neuberg; Papasogli-Poli. Sucrol. Morpurgo ; Wender. Sugar. Gentele; Mathieu-Plessy; Pettenkofer; Vidan; Villiers- Fayolle. In GLYCERIN: Boettger; Hager. In URINE: Arndt^ Cappezuoli; Einhorn; Eschbaum; Fehling; Fiebig; Haines; Hoppe-Seyler ; Jack; Jaksch, von-; Johnson; Kowarsky;. Leismer; Moore; Oliver; Ost; Otto; Penzoldt; PifTard; Schrei- ber; Schwartz; Seegen; Tollman; Ventre-Pascha; Wender. Sulfonal. Ritsert; Schwarz; Strobel; Vulpius. Sulphates in Urine. Freund. Sulphides. Alvarez-Jean ; Schott. Sulphites. Alvarez-Jean; Boedecker; Grant-Cohen. Sulphocarbolates. Prescott. Sulphocarbonates. Mermet. Sulphocyanic Acid. Colasanti; Kuelz; Munk. Sulphocyanides. Boettger. Sulphur. Bailey; Brunner; Gil; Schoenn; Vohl. HYDRIDE: Caro; Fischer; Hager; Lauth. In ILLUMINATING GAS: Wartha. Sulphur Compounds in Petroleum. Bird. Sulphuretted Hydrogen. Caro; Fischer; Hager; Lauth. Sulphuric Acid. Donath; Thresh; Vogel; Wormley. In ALU- MINIUM SULPHATE: Giesecke. In VINEGAR: Nessler; Pol- lacci. In WINE: Liebermann. Sulphurous Acid. Girardin; Kroupa; Reinsch; Schiff. In URINE: Salkowsky. Syntonin. Kuehn . INDEX OF SUBJECTS. 379* Syphilis Bacilli, Staining. Doutrelepont-Schiitz; Giacomij, Lewy; Lustgarten. Tannin. Baemes; Gardiner; Gayard; Griessmayer; Griggi;, Guyard; Hager; Oliver; Proctor; Saul; Seyda; Vogel; Watson;, Young. In DRUGS : Lutz. IN WINE : Carlinfanti. SOLUTION:. Carnoy. Tarry Matter. Donath. In AMMONIA: Kupf erschlaeger ; Witt- stein. Tarry Constituents of Lubricants Obtained from Petroleum. Holde. Tars, Differentiating. Hirschsohn. Tartaric Acid. Cailletet; Chapman-Smith; Crismer; Fenton; Hager; Mohler; Pusch. In WINE: Nessler. Taurine. Lang. Tellurium. Kerstal. Terpenes. Unverdorben-Fanchimont. Test-Paper. Boas; Boettger; Bourget; Chevreuil; Flueckiger^ Geissler; Greenwalt; Griess; Guenzburg; Herzberg; Hoff- mann; Houzeau; Kroupa; Lutke; Mann; Merget; Musculusj Oliver; Richardson; Schiff; Schoenbein; Schott; Selle; StahU Stevenin; Uffelmann; Weselsky; Wurster. Textile Fabrics. Lidoff; Liebermann; Maugin; Persoz; Schloss> berger; Schweitzer. Thalleioquin Reaction. Brand; Hyde. Thalline. Jaksch, Von-; Kotzebue; Penzoldt; Skraup. Thallium in Urine. Manne*. Thebaine. Mecke ; Melzer. Theine. Thompson. Theobromine. Francois ; Treumann. Thiophene. Meyer. Thiotolene. Laubenheimer. Thymol. Hammarsten-Robbert ; Thorns; Vitali. In MENTUOL: Eykmann. Tin. Deniges; Dryer; Rideal; Rogers; Schmatolla.. Tincture Iodine, Croton Oil in. Durien. Tinfoil, Lead in. Kopp. Titanium. Jackson; Lacroix; Weller. Tolu Balsam, Rosin in. Hirschsohn. Tolu Cement. Carnoy. 380 INDEX OF SUBJECTS. Toluene . Thorns . "Triacid" Mixture. Ehrlich. Trioxybenzene (Phloroglucin). Thorns. Tropaeolin. Lunge ; Miller. Tropine. Vre ven . Tubercle Bacilli Stain. B aimer- Fraentzel; Baumgarten; Beny- sek; Frankel; Gabbet; Gabbet-Ernst; Gibbs; Koch; Koch- Ehrlich; Hermann; Kaatzer; Pewsner-Nastinkow; Pfuhl-Petri; Rindfleisch; Weichselbaum. Turmeric. In MUSTARD: Wilder. In RHUBARB: Maisch; Op- wyrda; Wilder. Turpentine. Dragendorff; Vogel. CEMENT: Csoker (or Czoker); Parker. COLOPHONY MOUNTING MEDIUM: Lee. In COPAIVA: Hager. In ESSENTIAL OILS: Crismer; Gulli; McClellan- Forney; Maier; Merz. SOLUTION: Huehnefeld. Typhoid and Cholera Bacillus Stain. Kuehne. Typhoid and Tubercle Bacilli, Diazo Reaction for. Freden- wald-Ehrlich. Typhoid Fever Bacilli, Extraneous Organisms Among. Parietti. Typhoid. Richardson; Widal; Widal-Gruber. MEDIUM : Stod- dart. Tyrosin. Deniges; Frerich; Hoffmann; Piria; Piria-Staedeler; Scherer; Udransky; Wurster. Tyrotoxicon. Vauglm-Novy. Unrolling Sections. Duval. Unsaponifiable Substances in Fats. Holde. Uranium. Crolas-Ducker; Kern. Uranium Acetate, Fixing Fluid. Schenk. Urates and Uric Acid. Riegler. Urea. Bloxham; Bruecke; Claus; Davy-Leconte; Huefner; Liebig- Woehler ; Luedy; Musculus; Schiff; Smith-Chapman; Udransky. Uric Acid. Archetti; Babo; Bayrac; Behier; Berlin; Bertrand; Deniges; Dieterich; Fokker; Hopkins; Jaksch, von-; Leconte; Magnier de la Source; Neubauer; Riegler; Schiff; Schulten- Wetzlar; Rudish-Boroschek ; Schwanert; Source; Stadthagen. In BLOOD: Garrod; Luff. In URINARY CALCULI: Deniges. Urinary Calculi, Uric Acid in. Deniges. Urinary Deposits. Bohland. INDEX OF SUBJECTS. 381 Urine. Abram (lead); Alpers (albumin); Allen (nitrogen); Anstie (alcohol) ; Arnold (aceto-acetic acid) ; Barfoed (glucose and lactose); Baumann (bacterial products; carbohydrates; glycerin) ; Bayer (acetone) ; Bayrac (uric acid) ; Binz (quinine) ; Bourget (iodides) ; Bremer (glucose) ; Bretet (glucose ; levulose ; saccharose); Bruecke (biliary pigments); Carter (indican); Chautard (acetone); Downe (pus); Dragendorff (phenol); Drewson (acetone); Ebstein-Muller (pyrocatechin) ; Edlefsen (chloric acid) ; phenetidin) ; Einhorn (sugar) ; Eiselt (melanin) ; Eschbaum (sugar) ; Eschbach-Gawalowsky (albumin) ; Francis (biliary acids); Frerich (leucin; tyrosin); Freund (sulphates); Gallois (inosite) ; Gawalowsky (albumin) ; Gerhardt (acetone) ; Grismer (glucose); Grocco (creatinine) ; Guerin (albumin); albuminoids); Hager (albumin); Hahnemann (copper; lead); Haines (sugar); Hammarsten (caffeine; indican; globulin); Harnack (iodine); Haslan (albumin); Heintz (potassium); Heller (albumin; indican; urophain); Heller-Teichmann (blood) ; Heynsius (albumin) ; Hindenlang (albumin) ; Hoppe- Seyler (sugar; santonin); Huehnefeld (blood); Ilimow (albu- min); Jack (sugar); Jaffe (indican); Jaksch, von- (diacetic acid; melanin; sugar); Jakobsohn (epithelia); Jaworowsky (albumin; peptone); Johnson (sugar); Jolles (albumin; iodine; mercury); Joly-Pacquelin (pyrophosphoric acid); Kerner (quinine); Klett (indican); Kowarsky (sugar); Kuelz (sulpho- cyanic acid); Landsberg-Wislicenus (morphine); Latschen- berger (ammonia) ; Lechini (blood) ; Leffmann ; Legal (acetone) Leismer (sugar); Le Noble (acetone); Luchsinger (glycerin); Ludwig (mercury) ; Lugol (albumin) ; Mahomed (hemoglobin) ; Mai-Hilger (coloring); Marme (cadmium; thallium); Martin (peptones); Millard (albumin); Moore (glucose; sugar); Mueller (hydrogen sulphide); Munk (hemapheinic ; sulpho- cyanic acid); Neubauer (ammonia; chloroform); Newmann- Wender (glucose; hydroquinone ; pyrocatechin); Nobel (co- paiva; gurjun oil); Obermayer (indican); Ott (bilirubin); Pacquelin-Joly (pyrophosphoric acid) ; Patton (globulin) ; Piffard (sugar); Petri (kairin); Pollacci (albumin); Posner (albumin; peptone); Pratesi (glucose); Proescher (bilirubin); Proksch (rhubarb); Renzone (kairin); Quirini (glucose); Raabe (albumin); Rabuteau (bromic acid; chloric acid); -382 INDEX OF SUBJECTS. Rafaele (albumin); Ralfe (acetone; peptone); Randolph (peptones) ; Reichardt (arsenic) ; Reissner (nucleo-albumin) ; Rheoch (oxalic acid); Reynold (acetone); Reynold- Gunning (acetone); Roberts (albumin; glucose); Roberts- Stolnikoff albumin) ; Roch (albumin) ; Roman-Delluc (uro- bilin); Rosenbach (indigo-red); Rossel (blood); Ruber (glu- 'cose); Salkowsky (peptone; potassium; sulphurous acid); Salkowsky-Leubes (mucin); Sandlund (iodine); Schoenbein (nitric acid; nitrous acid); Schulz (nitric acid); Schwartz (sugar); Schwicker (acetone); Scivoletto (hydriodic acid); Seivolete (iodine); Senator-Lehmann (globulin); Siebold- Bradbury (salicylic acid); Stevenson (hemoglobin); Stilling- fleet-Johnson (creatinine) ; Stock (acetone); Studenski (urobilin); Thormaehlin (melanin); Teichman- Heller (blood); Tre*trop (albumin); Vitali (Martius' yellow; quinine); Weil- Gilbert (indican) ; Wender (sugar) ; Weyl (nitric acid) ; Wislicenus-Landsberg (morphine) ; Woodbury (alcohol) ; Yvon (acetanilid; antifebrin); Zeller (melanin) ; Zouchlos (albumin). Urobilin in Urine. Roman-Delluc; Studenski. Urohematin. Harley. Urophaine in Urine. Heller. Valeraldehyde in Valerianic Acid. Finzelberg. Valerian Oil. Flueckiger. Valerianic Acid, Valeraldehyde in. Finzelberg. Vanadates, Meta. Werther. Vanadium and Gold Method. Upson. Vanadium Nerve Stain. Wolter. Vapors, Mercury, in Atmosphere. Gaglio. Varnish, Asphalt. Kitton. Varnish for Mounting Sections. Weigert. Vegetable Coloring Matter in Wine. Hertz. Vegetable Fats. Allen; Schoenvogel; Welmann. In PETRO- LATUM: Crouzel-Dupin. Vegetable Fibers. Frankenstein. Venice-Turpentine Mounting Medium. Vosseler. Veratrine. Ferraro ; Mecke ; Melzer ; Robin ; Schumpelitz ; Trapp ; Wender; Weppen. Vinegar. For CARAMEL: Crampton-Simons. For COPPER: Hager. For MINERAL ACIDS: Ashley; Chiappe; Griggi; INDEX OF SUBJECTS. 383 Hehner; Jorrissen; Mallet; Nessler; Pollacci; Strohl; Whar- ton; Witz. Violet Ammonia-Garb olate. Hermann. Water. Claus; Cavalli (alkalinity); Dupasquier (organic mat- ter); Finkelburg (fecal matter); Fleck (ammonia); Gottstein (bacteria) ; Griess (fecal matter) ; Guldensteen (copper) ; Himly (illuminating gas); Cazeneuve-Defournel (nitrates); Marchand (organic matter); Maschke (nitrates). ANILINE: Ehrlich-Weigert-Koch ; Koch. In ALCOHOL: Casoria; De- brunner; Mann; Winkler. In BUTTER: Wibel. In ETHER: Boettger; Mann; Napier; Romei. In ESSENTIAL OILS: Leuchs. In SPIRIT NITROUS ETHER: Lloyd. POLLUTED: Causse. POTABLE: Brantlecht; Hager. Wax. Donath (resin) ; Donath-Schmidt (resin) ; Estcourt-Parry (paraffin; resin; stearin); Geith; Hager. Wax Feet. Vosseler. Wheat Flour. Donny; Wittmack. Wheat, Oiled. Himly. White-Lead Cement. Kitton. White-Lead Paper. Schott. Wine. Arata (dyes); Brand (abrastol); Carpene (tannin); Cazeneuve (dyes); Dupre' (dyes); Faure (dyes); Giessler (fuchsine); Girard (dyes); Heise (Kermes coloring matter); Liebermann (sulphurous acid); Nessler (citric acid; tartaric acid; pigments); Niviere- Hubert (fluorides); Pasteur- Wurtz (fuchsine); Pradines (fuchsine); Spicea (salicylic acid). Woman's Milk. Umikoff. Wood Fiber in Paper. Friedlander; Wolesky. Wood Pulp. Kaiser; Molesch. Wool. Jacquemin; Jandrier (cotton); Liebermann; Lidoff; Overbeck (cotton); Peltier. Xanthin. Hoppe-Seyler; Salomon; Simon; Strecker; Weidel. Xanthoprotein. Mulder. Xylene. Thorns. Zinc. Deniges; Gayard or Guyard (manganese); Rinman; Stahl. Zymozen of Rennet. Klemperer. SHORT-TITLE CATALOGUE OF THE PUBLICATIONS OF JOHN WILEY & SONS, NEW YORK, LOXDON: CHAPMAN & HALL, LIMITED. ARRANGED UNDER SUBJECTS. Descriptive circulars sent on application. 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Bernadou's Smokeless Powder, Nitro-cellulose, and the Theory of the Cellulose Molecule i2mo, 2 50 * Bruff's Text-book Ordnance and Gunnery 8vo, 6 oo Chase's Screw Propellers and Marine Propulsion 8vo, 3 oo Craig's Azimuth 4to, 3 50 Crehore and Squire's Polarizing Photo-chronograph 8vo, 3 oo Cronkhite's Gunnery for Non-commissioned Officers 24mo morocco, 2 oo * Davis's Elements of Law ,. 8vo, 2 50 * ; Treatise on the Military Law of United States 8vo, 7 oo Sheep, 7 50 De Brack's Cavalry Outpost Duties. (Carr.) 241110 morocco, 2 oo Dietz's Soldier's First Aid Handbook i6mo, morocco, i 25 * Dredge's Modern French Artillery 4to, half morocco, 15 oo Durand's Resistance and Propulsion of Ships 8vo, 5 oo * Dyer's Handbook of Light Artillery i2mo, 3 oo Eissler's Modern High Explosives 8vo, 4 oo * Fiebeger's Text-book on Field Fortification SmairSvo, 2 oo Hamilton's The Gunner's Catechism i8mo, i oo^ * Hoff's Elementary Naval Tactics 8vo, i 50 Ingalls's Handbook of Problems in Direct Fire 8vo, 4 oo * Ballistic Tables 8vo, i 50 * Lyons's Treatise. on Electromagnetic Phenomena. Vols. I. and II. .Svo.each, 6 oo * Mahan's Permanent Fortifications. (Mercur.) 8vo, half morocco, 7 50 Manual for Courts-martial i6mo j morocco, i 50 * Mercur's Attack of Fortified Places i2mo, 2 oo * Elements of the Art of War 8vo, 4 oo Metcalf' s Cost of Manufactures And the Administration of Workshops, Public and Private 8vo, 5 oo * Ordnance and Gunnery i2mo, 5 oo Murray's Infantry Drill Regulations i8mo, paper, 10 * Phelps's Practical Marine Surveying 8vo, 2 50 Powell's Army Officer's Examiner i2mo, 4 oo Sharpe's Art of Subsisting Armies in War i8mo, morocco, i 50 * Walke's Lectures on Explosives ovo, 4 oo * Wheeler's Siege Operations and Military Mining 8vo, 2 'oo Winthrop's Abridgment of Military Law lamo, 2 50 Woodhull's Notes on Military Hygiene i6mo r i 50 Young's Simple Elements of Navigation i6mo morocco, i oo Second Edition, Enlarged and Revised i6mo, morocco, 2 oo ASSAYING. Fletcher's Practical Instructions in Quantitative Assaying with the Blowpipe. i2mo, morocco, i 30 Furman's Manual of Practical Assaying 8vo, 3 oo Miller's Manual of Assaying i2mo, i oo O'Driscoll's Notes on the Treatment of Gold Ores 8vo 2 oo Ricketts and Miller's Notes on Assaying 8vo, 3 oo Ulke's Modern Electrolytic Copper Refining 8vo, 3 oo Wilson's Cyanide Processes i2mo, i 50 Chlorination Process i2mo, i 50 ASTRONOMY. Gomstock's Field Astronomy for Engineers 8vo, 2 50 Craig's Azimuth 4to, 3 50 Doolittle's Treatise on Practical Astronomy 8vo, 4 oo Gore's Elements of Geodesy 8vo, 2 50 Hayford's Text-book of Geodetic Astronomy 8vo, 3 oo Merriman's Elements of Precise Surveying and Geodesy 8vo, 2 50 * Michie and Harlow's Practical Astronomy 8vo, 3 oo * White's Elements of Theoretical and Descriptive Astronomy i2mo, 2 oo BOTANY. Davenport's Statistical Methods, with Special Reference to Biological Variation. i6mo, morocco, i 25 Thome and Bennett's Structural and Physiological Botany iGmo, 2 25 Westermaier's Compendium of General Botany. (Schneider.) 8vo, 2 oo CHEMISTRY. kdriance's Laboratory Calculations and Specific Gravity Tables i2mo, x 25 Allen's Tables for Iron Analysis 8vo, 3 oo Arnold's Compendium of Chemistry. (Mandel.) (In preparation.) Austen's Notes for Chemical Students i2ino, I 50 Bernadou's Smokeless Powder. Nitro-cellulose, and Theory of the Cellulose Molecule i2mo, J 50 Bolton's Quantitative Analysis 8vo, i 50 * Browning's Introduction to the Rarer Elements 8vo, I 50 Brush and Penfield's Manual of Determinative Mineralogy 8vo, 4 oo Classen's Quantitative Chemical Analysis by Electrolysis. (Boltwood.) . . . 8vo, 300 Cohn's Indicators and Test-papers I2mo, 2 oo Tests and Reagents 8vo, 3 oo Copeland's Manual of Bacteriology. (In preparation.) Craft's Short Course in Qualitative Chemical Analysis. (Schaeffer.). . . . I2mo, I 50 Drechsel's Chemical Reactions. (Merrill. ) 12 mo, i 25 Duhem's Thermodynamics and Chemistry. (Burgess.) 8vo, 4 oo Eissler's Modern High Explosives 8vo, 4 oo EfEront's Enzymes and their Applications. (Prescott.) ................ 8vo, 3 oo Erdmann's Introduction to Chemical Preparations. '(Dunlap.) ........ i2mo, i 25 Fletcher's Practical Instructions in Quantitative Assaying with the Blowpipe i2mo, morocco, i 50 Fowler's Sewage Works Analyses ................................. i2mo, 2 oo Fresenius's Manual of Qualitative Chemical Analysis. (Wells.) ......... 8vo, 5 oo Manual of Qualitative Chemical Analysis. Parti. Descriptive. (Wells.) 8vo, 3 oo System of Instruction in Quantitative Chemical Analysis. (Cohn.) 2 vols. (Shortly.) Fuertes's Water and Public Health ................................ i2mo, i 50 Furman's Manual of Practical Assaying ............................. 8vo, 3 oo Gill's Gas and Fuel Analysis for Engineers .......................... i2mo, i 25 Grotenfelt's Principles of Modern Dairy Practice. (Wo 11.) ............. i2mo, 2 oo Hammarsten's Text-book of Physiological Chemistry. (Mandel.) ....... 8vo, 4 oo Helm's Principles of Mathematical Chemistry. (Morgan.) ............ i2mo, i 50 Hinds's Inorganic Chemistry ...................................... 8vo, 3 oo * Laboratory Manual for Students ........... , .................. i2mo, 75 Holleman's Text-book of Inorganic Chemistry. (Cooper.) ............. 8vo, 2 50 Text-book of Organic Chemistry. (Walker and Mott.) ........... .8vo, 2 50 Hopkins's Oil-chemists' Handbook ................................. 8vo, 3 oo Jackson's Directions for Laboratory Work in Physiological Chemistry. .8vo, i oo Keep's Cast Iron ............................................ ..... 8vo, 2 50 Ladd's Manual of Quantitative Chemical Analysis. . .................. I2mo. i oo Landauer's Spectrum Analysis. (Tingle.) ............................ 8vo, 3 oo Lassar-Cohn's Practical Urinary Analysis. (Lorenz.) ................ i2mo, i oo Leach's The Inspection and Analysis of Food with Special Reference to State Control. (In preparation.) Lob's Electrolysis and Electrosynthesis of Organic Compounds. (Lorenz.) i2mo, i oo Mandel's Handbook for Bio-chemical Laboratory .................... i2mo, i 50 * Martin's Laboratory Guide to Qualitative Analysis with the Blowpipe . . i2mo, 60 Mason's Water-supply. (Considered Principally from a Sanitary Standpoint.) 3d Edition, Rewritten ...................... . ............. 8vo, 4 oo Examination of Water. (Chemical and Bacteriological.) ......... i2mo, i 25 Meyer's Determination of Radicles in Carbon Compounds. (Tingle.). .i2mo, i oo MiUer's Manual of Assaying ...................................... i2mo, i oo Mizter's Elementary Text-book of Chemistry ........................ i2mo, i 50 Morgan's Outline of Theory of Solution and its Results ................ i2mo, i oo Elements of Physical Chemistry ............................. , 121110, 2 oo Nichols's Water-supply. (Considered mainly from a Chemical and Sanitary Standpoint, 1883.) ........................................ 8vo, 2 50 O'Brine's Laboratory Guide in Chemical Analysis ..................... 8vo, 2 oo O'Driscoll's Notes on the Treatment of Gold Ores ...................... 8vo, 2 oo Ost and Kolbeck's Text-book of Chemical Technology. (Lorenz Bozart.) (In preparation.) * Penfield's Notes on Determinative Mineralogy and Record of Mineral Tests. 8vo, paper, 50 Pictet's The Alkaloids and their Chemical Constitution. (Biddle.) (In Pinner's Introduction to Organic Chemistry. (Austen.) .............. i2mo, i 50 Poole's Calorific Power of Fuels .................................... 8vo. 3 oo * Reisig's Guide to Piece-dyeing .................................... 8vo, 25 oo Richards and Woodman's Air .Water, and Food from a Sanitary Standpoint . 8vo, 2 oo Richards's Cost of Living as Modified by Sanitary Science ............. i2mo, i oo Cost of Food a Study in Dietaries .............. . .............. I2mo, i oo * Richards and Williams's The Dietary Computer ..................... 8vo, i 50 Ricketts and Russell's Skeleton Notes upon Inorganic Chemistry. (Part I. Non-metallic Elements.) ........................ 8vo, morocco, 75 M Ricketts and Miller's Notes on Assaying 8vo, 3 oo Rideal's Sewage and the Bacterial Purification of Sewage 8vo, 3 50 Ruddiman's Incompatibilities in Prescriptions 8vo, 2 oo Salkowski's Physiological and Pathological Chemistry. (Orndorff.) (Shortly.) Schimpf's Text-book of Volumetric Analysis tamo, Essentials of Volumetric Analysis i2mo, Spencer's Handbook for Chemists of Beet-sugar Houses i6mo, morocco, Handbook for Sugar Manufacturers and their Chemists. .i6mo, morocco, Stockbridge's Rocks and Soils 8vo, 50 * Tillman's Elementary Lessons in Heat 8vo, 50 * Descriptive General Chemistry 8vo 3 oo Treadwell's Qualitative Analysis. (Hall.) 8vo, 3 oo Turneaure and Russell's Public Water-supplies 8vo, ' 5 oo Van Deventer's Physical Chemistry for Beginners. (Boltwood.) I2mo, I 50 * Walke's Lectures on Explosives 8vo, 4 oo Wells's Laboratory Guide in Qualitative Chemical Analysis 8vo, i 50 Short Course in Inorganic Qualitative Chemical Analysis for Engineering Students i2mo, I 50 Whipple's Microscopy of Drinking-water 8vo, 3 50 Wiechmann's Sugar Analysis Small 8vo. 2 59 Wilson's Cyanide Processes 1 2mo, i 50 Chlorination Process i2mo, i 50 Wulling's Elementary Course in Inorganic Pharmaceutical and Medical Chem- istry i2mo 2 oo CIVIL ENGINEERING. BRIDGES AND ROOFS. HYDRAULICS. MATERIALS OF ENGINEERING RAILWAY ENGINEERING. Baker's Engineers' Surveying Instruments i2mo, 3 oo Bixby's Graphical Computing Table Paper 1 9* X 24* inches, 25 ** Burr's Ancient and Modern Engineering and the Isthmian Canal. (Postage , 27 cents additional.) 8vo, net, 3 50 Comstock's Field Astronomy for Engineers 8vo, 3 50 Davis's Elevation and Stadia Tables 8vo, I o Elliott's Engineering for Land Drainage 121110, i 50 Practical Farm Drainage 1 2010, i oo FolwelTs Sewerage. (Designing and Maintenance.) 8vo, 3 *o Freitag's Architectural Engineering. 2d Edition, Rewritten 8vo, 3 50 French and Ives's Stereotomy 8vo, 2 50 Goodhue's Municipal Improvements 1 2itto, I. 75 Goodrich's Economic Disposal of Towns' Refuse 8vo, 3 50 Gore's Elements of Geodesy 8vo, 2 30 Hayford's Text-book of Geodetic Astronomy 8vo, 3 *o Howe's Retaining Walls for Earth I2mo, x 35 Johnson's Theory and Practice of Surveying Small 8vo, 4 oo Statics by Algebraic and Graphic Methods 8vo, 2 oo Kiersted's Sewage Disposal 121110, i 35 Laplace's Philosophical Essay on Probabilities. (Truscott and Emory.) i2tno, 2 oo Mahan's Treatise on Civil Engineering. (1873 ) (Wood.) 8vo, 5 oo * Descriptive Geometry 8vo, i 50 Merriman's Elements of Precise Surveying and Geodesy 8vo, 2 50 Elements of Sanitary Engineering 8vo, 2 oo Merriman and Brooks's Handbook for Surveyors i6mo, morocco, 2 oo Nugent's Plane Surveying 8vo, 3 50 Ogden's Sewer Design i2mo, 2 oo Patton's Treatise on Civil Engineering 8vo half leather, 7 50 5 Reed's Topographical Drawing and Sketching 4to, 5 oo Rideal's Sewage and the Bacterial Purification of Sewage 8vo, 3 50 Siebert and Biggin's Modern Stone-cutting and Masonry 8vo, i 50 Smith's Manual of Topographical Drawing. (McMillan.) 8vo, 2 50 Sondericker's Graphic Statics, wnn Applications to Trusses, Beams, and Arches 8vo, 2 oo * Trautwine's Civil Engineer's Pocket-book i6mo, morocco, 5 oo Wait's Engineering and Architectural Jurisprudence 8vo, 6 oo Sheep, 6 50 Law of Operations Preliminary to Construction in Engineering and Archi- tecture 8vo, 5 oo Sheep, 5 50 Law of Contracts 8vo, 3 oo Warren's Stereotomy Problems in Stone-cutting 8vo, 2 50 Webb's Problems in the Use and Adjustment of Engineering Instruments. i6mo, morocco, i 25 * Wheeler's Elementary Course of Civil Engineering 8vo, 4 oo Wilson's Topographic Surveying 8vo, 3 50 BRIDGES AND ROOFS. Boiler's Practical Treatise on the Construction of Iron Highway Bridges. .8vo, 2 oo * Thames River Bridge 4to, paper, 5 oo Burr's Course on the Stresses in Bridges and Roof Trusses, Arched Ribs, and Suspension Bridges 8vo, 3 50 Du Bois's Mechanics of Engineering. VoL II Small 4to, 10 oo Foster's Treatise on Wooden Trestle Bridges 4to, 5 oo Fowler's Coffer-dam Process for Piers 8vo, 2 50 Greene's Roof Trusses 8vo, i 25 Bridge Trusses 8vo, 2 50 Arches in Wood, Iron, and Stone 8vo, 2 50 Howe's Treatise on Arches 8vo 4 oo Design of Simple Roof-trusses in Wood and Steel 8vo, 2 oo Johnson, Bryan, and Turneaure's Theory and Practice in the Designing of Modern Framed Structures Small 4to, 10 oo Merriman and Jacoby's Text-book on Roofs and Bridges: Parti. Stresses in Simple Trusses 8vo, 2 50 Part n. Graphic Statics 8vo, 2 50 Part III. Bridge Design. 4th Edition, Rewritten 8vo, 2 30 Part IV. Higher Structures 8vo, 2 50 Morison's Memphis Bridge 4to, 10 oo Waddell's De Pontibus, a Pocket-book for Bridge Engineers. . . i6mo, morocco, 3 oo Specifications for Steel Bridges i2mo, i 23 Wood's Treatise on the Theory of the Construction of Bridges and Roofs.Svo, 2 oo Wright's Designing of Draw-spans: Part I. Plate-girder Draws 8vo, 2 50 Part II. Riveted-truss and Pin-connected Long-span Draws 8vo, 2 50 Two parts in one volume 8vo, 3 50 HYDRAULICS. Bazin's Experiments upon the Contraction of the Liquid Vein Issuing from an Orifice. (Trautwine.) 8vo, 2 oo Bovey's Treatise on Hydraulics 8vo, 5 oo Church's Mechanics of Engineering 8vo, 6 oo Diagrams of Mean Velocity of Water in Open Channels paper, i 50 Coffin's Graphical Solution of Hydraulic Problems i6mo, morocco, 2 50 Flather's Dynamometers, and the Measurement of Power I2mo, 3 oo Folwell's Water-supply Engineering t 8vo, 4 oo Frizell's Water-power , 8vo, 5 oo Fuertes's Water and Public Health izmo, i 50 Water-filtration Works i2mo, 2 50 Ganguillet and Kutter's General Formula for the Uniform Flow of Water in Rivers and Other Channels. (Bering and Trautwine.) 8vo, 4 oo Hazen's Filtration of Public Water-supply 8vo, 3 oo Hazlehurst's Towers and Tanks for Water- works 8vo. 2 50 Herschel's 115 Experiments on the Carrying Capacity of Large, Riveted, Metal Conduits 8vo, 2 oo Mason's Water-supply. (Considered Principally from a Sanitary Stand- point.) 3d Edition, Rewritten 8vo, 4 oo Merriman's Treatise on Hydraulics, pth Edition, Rewritten 8vo, 5 oo * Michie's Elements of Analytical Mechanics 8vo, 4 oo Schuyler's Reservoirs for Irrigation, Water-power, and Domestic Water- supply Large 8vo, 5 oo ** Thomas and Watt's Improvement of Riyers. (Post., 44 c. additional), 4to, 6 oo Turneaure and Russell's Public Water-supplies 8vo, 5 oo Wegmann's Design and Construction of Dams 4to, 5 oo Water-supply of the City of New York from 1658 to'iSgs 4to, 10 oo Weisbach's Hydraulics and Hydraulic Motors. (Du Bois.) 8vo, 5 oo Wilson's Manual of Irrigation Engineering Small 8vo, 4 oo Wolff's Windmill as a Prime Mover 8vo, 3 oo Wood's Turbines 8vo, a 50 Elements of Analytical Mechanics 8vo, 3 oo MATERIALS OF ENGINEERING. Baker's Treatise on Masonry Construction 8vo, 5 oo Roads and Pavements 8vo, 5 oo Black's United States Public Works Oblong 4to, 5 oo Sovey's Strength of Materials and Theory of Structures 8vo, 7 SO Burr's Elasticity and Resistance of the Materials of Engineering. 6th Edi- tion, Rewritten 8vo, 7 So Byrne's Highway Construction 8vo, 5 oo Inspection of the Materials and Workmanship Employed in Construction. i6mo, 3 oo Church's Mechanics of Engineering 8vo, 6 oo Du Bois's Mechanics of Engineering. Vol. I Small 4to, 7 50 Johnson's Materials of Construction Large 8vo, 6 oo Keep's Cast Iron 8vo, 2 50 Lanza's Applied Mechanics 8vo, 7 50 Martens's Handbook on Testing Materials. (Henning.) 2 vols 8vo. 7 50 Merrill's Stones for Building and Decoration 8vo, 5 oo Merriman's Text-book on the Mechanics of Materials 8vo, 4 oo Strength of Materials i2mo, i oo Metcalf's Steel. A Manual for Steel-users i2mo, 2 oo Patton's Practical Treatise on Foundations 8vo, 5 oo Rockwell's Roads and Pavements in France i2mo, i 25 Smith's Wire: Its Use and Manufacture Small 4to, 3 oo Materials of Machines I2mo, i oo Snow's Principal Species of Wood 8vo, 3 50 Spalding's Hydraulic Cement i2mo, 2 oo Text-book on Roads and Pavements i2mo, 2 oo 7 Thurston's Materials of Engineering. 3 Parts 8vo, 8 oo Part I. Non-metallic Materials of Engineering and Metallurgy 8vo, 2 oo Part n. Iron and Steel 8vo, 3 50 Part III. A Treatise on Brasses, Bronzes, and Other Alloys and their Constituents 8vo, 2 50 Thurston's Text-book of the Materials of Construction 8vo, 5 oo Tillson's Street Pavements and Paving Materials 8vo, 4 oo Waddell's De Pontibus. (A Pocket-book for Bridge Engineers.) . . i6mo, mor., 3 oo Specifications for Steel Bridges i2mo, i 25 Wood's Treatise on the Resistance of Materials, and an Appendix on the Pres- ervation of Timber 8vo, 2 oo Elements of Analytical Mechanics 8vo, 3 oo Wood's Rustless Coatings. (Shortly.') RAILWAY ENGINEERING. Andrews's Handbook for Street Railway Engineers. 3X5 inches, morocco, i 25 Berg's Buildings and Structures of American Railroads 4to, 5 oo Brooks's Handbook of Street Railroad Location i6mo. morocco, I 50 Butts's Civil Engineer's Field-book i6mo, morocco, 2 50 CrandalTs Transition Curve i6mo, morocco, i 50 Railway and Other Earthwork Tables 8vo, i 50 Dawson's "Engineering" and Electric Traction Pocket-book. i6mo, morocco, 5 oo Dredge's History of the Pennsylvania Railroad: (1879) Paper, 5 oo * Drinker's Tunneling, Explosive Compounds, and Rock Drills, 4to, half mor., 25 oo Fisher's Table of Cubic Yards Cardboard. 25 Godwin's Railroad Engineers' Field-book and Explorers' Guide i6mo, mor., 2 50 Howard's Transition Curve Field-book i6mo, morocco, i so Hudson's Tables for Calculating the Cubic Contents of Excavations and Em- bankments 8vo, i oo Molitor and Beard's Manual for Resident Engineers i6mo, i oo Nagle's Field Manual for Railroad Engineers i6mo, morocco. 3 oo Philbrick's Field Manual for Engineers " i6mo, morocco, 3 oo Pratt and Alden's Street-railway Road-bed 8vo, 2 oo Searles's Field Engineering i6mo, morocco, 3 oo Railroad Spiral. i6mo, morocco, i 50 Taylor's Prismoidal Formulae and Earthwork 8vo, i 50 * Trautwine's Method of Calculating the Cubic Contents of Excavations and Embankments by the Aid of Diagrams 8vo, 2 oo The Field Practice of [Laying Out Circular Curves for Railroads. iamo, morocco, 2 50 * Cross-section Sheet Paper, 25 Webb's Railroad Construction. 2d Edition, Rewritten i6mo. morocco, 5 oo Wellington's Economic Theory of the Location of Railways Small 8vo, 5 oo DRAWING. Barr's Kinematics of Machinery 8vo, 2 50 * Bartlett's Mechanical Drawing 8vo, 3 oo * " " " Abridged Ed 8vo, i 50 Coolidge's Manual of Drawing 8vo, paper, i oo Durley's Kinematics of Machines 8vo, 4 oo Hill's Text-book on Shades and Shadows, and Perspective 8vo, 2 oo Jones's Machine Design: Part I. Kinematics of Machinery 8vo, i 50 Part n. Form, Strength, and Proportions of Parts 8vo, 3 oo 8 Mac Cord's Elements of Descriptive Geometry 8vo, 3 oo Kinematics; or, Practical Mechanism 8vo, 5 oo Mechanical Drawing 4to, 4 oo Velocity Diagrams 8vo, i 50 * Mahan's Descriptive Geometry and Stone-cutting 8vo, i 50 Industrial Drawing. (Thompson.) 8vo, 3 50 Reed's Topographical Drawing and Sketching 4to, 5 oo Reid's Course in Mechanical Drawing 8vo, 2 oo Text-book of Mechanical Drawing and Elementary Machine Design. .8vo. 3 oo Robinson's Principles of Mechanism 8vo, 3 oo Smith's Manual of Topographical Drawing. (McMillan.) 8vo, 2 50 Warren's Elements of Plane and Solid Free-hand Geometrical Drawing . . 1 2mo, I oo Drafting Instruments and Operations I2mo, i 25 Manual of Elementary Projection Drawing I2mo, i 50 Manual of Elementary Broblems in the Linear Perspective of Form and Shadow i2mo, i oo Plane Problems in Elementary Geometry i2mo, i 25 Primary Geometry I2mo, 75 Elements of Descriptive Geometry, Shadows, and Perspective 8vo, 3 50 General Problems of Shades and Shadows 8vo, 3 oo Elements of Machine Construction and Drawing 8vo, 7 So Problems. Theorems, and Examples in Descriptive Geometry 8vo, 2 50 Weisbach's Kinematics and the Power of Transmission. (Hermann and Klein.) 8vo, 5 oo Whelpley's Practical Instruction in the Art of Letter Engraving i2mo, 2 oo Wilson's Topographic Surveying 8vo, 3 50 Free-hand Perspective 8vo, a 50 Free-hand Lettering 8vo, I oo Woolf' s Elementary Course in Descriptive Geometry Large 8vo, 3 oo ELECTRICITY AND PHYSICS. Anthony and Brackett's Text-book of Physics. (Magie.) Small 8vo, 3 oo Anthony's Lecture-notes on the Theory of Electrical Measurements lamo, i oo Benjamin's History of Electricity 8vo, 3 oo Voltaic Cell 8vo, 3 oo Classen's Quantitative Chemical Analysis by Electrolysis. (Boltwood.). .8vo, 3 oo Crehore and Sauier's Polarizing Photo-chronograph 8vo, 3 oo Dawson's "Engineering" and Electric Traction Pocket-book. ,i6mo, morocco, 5 oo Dolezalek's Theory of the Lead Accumulator. (Storage Battery.) (Shortly.) (Von Ende.) Duhem's Thermodynamics and Chemistry. (Burgess.) 8vo, 4 oo Flather's Dvnamometers, and the Measurement of Power i2mo, 3 oo Giioert's De Magnete. (Mottelay.) 8vo, 2 50 Hanchett's Alternating Currents Explained. (Shortly.) Holman's Precision of Measurements 8vo, 2 oo Telescopic Mirror-scale Method, Adjustments, and Tests. . . Large 8vo, 75 Lanaauer's Spectrum Analysis. (Tingle.) 8vo, 3 oo Le Chatelier's High-temperature Measurements. (Boudouard .burgess. )i2mo, 3 oo Lob's Electrolysis and Electrosynthesis of Organic Compounds. (Lorenz.) 12010, i oo * Lyons's Treatise on Electromagnetic Phenomena. Vo Is. I. and II. bvo, each, 6 oo * Michie. Elements of Wave Motion Relating to Sound and Light 8vo . 4 oo Niaudet's Elementary Treatise on Electric Batteries. (Fishoack. ) i2mo, 2 50 * Parshall and Hobart's Electric Generators Small 4to. half morocco, 10 oo * Rosenberg's Electrical Engineering. (Haldane Gee Kinzbrunner.). . . .8vo, i 50 Ryan, Norris, and Hoxie's Electrical Machinery. Vol. 1 8vo, 2 50 Thurston's Stationary Steam-engines 8vo, 2l$o * Tollman's Elementary Lessons in Heat 8vo, i 50 9 Tory and Pitcher's Manual of Laboratory Physics. * Small 8vo, 2 oo Ulke's Modern Electrolytic Copper Refining 8vo, 3 oo LAW. * Davis's Elements of Law 8vo, 2 50 * Treatise on the Military Law of United States 8vo, 7 oo * Sheep, 7 50 Manual for Courts-martial i6mo, morocco, i 50 Wait's Engineering and Architectural Jurisprudence 8vo, 6 oo Sheep, 6 50 Law of Operations Preliminary to Construction in Engineering and Archi- tecture 8vo, 5 oo Sheep, 5 50 Law of Contracts 8vo, 3 oo Winthrop's Abridgment of Military Law i2mo, 2 50 MANUFACTURES. Bernadou's Smokeless Powder Nitro-cellulose and Theory of the Cellulose Molecule i2mo, 2 50 Holland's Iron Founder i2mo, 2 50 " The Iron Founder," Supplement i2mo, 2 50 Encyclopedia of Founding and Dictionary of Foundry Terms Used in the Practice of Moulding i2mo, 3 oo Eissler's Modern High Explosives 8vo, 4 oo Effront's Enzymes and their Applications. (Prescott.) 8vo, 3 oo Fitzgerald's Boston Machinist i8mo, i oo Ford's Boiler Making for Boiler Makers i8mo, i oo Hopkins's Oil-chemists' Handbook 8vo, 3 oo Keep's Cast Iron 8vo, 2 50 Leach's The Inspection and Analysis of Food with Special Reference to State Control. (In preparation.} Metcalf's Steel A Manual for Steel-users i2mo, 2 oo Metcalfe's Cost of Manufactures And the Administration of Workshops, Public and Private 8vo, 5 oo Meyer's Modern Locomotive Construction 4to, 10 oo * Reisig's Guide to Piece-dyeing 8vo, 25 oo Smith's Press-working of Metals 8vo, 3 oo Wire: Its Use and Manufacture Small 4to, 3 oo Spalding's Hydraulic Cement i2mo, 2 oo Spencer's Handbook for Chemists of Beet-sugar Houses i6mo, morocco, 3 oo Handbook lor sugar Manufacturers and their Chemists.. . i6mo, morocco, 2 oo Thurston's Manual of Steam-boilers, their Designs, Construction and Opera- tion 8vo, 5 oo * Walke's Lectures on Explosives 8vo, 4 oo West's American Foundry Practice i2mo, 2 50 Moulder's Text-book i2mo, 2 50 Wiechmann's Sugar Analysis. Small 8vo, 2 50 Wolff's Windmill as a Prime Mover 8vo, 3 oo Woodbury's Fire Protection of Mills 8vo, 2 50 MATHEMATICS. Baker's Elliptic Functions 8vo, i 50 * Bass's Elements of Differential Calculus 1 2mo, 4 oo Briggs's Elements of Plane Analytic Geometry lamo, i oo 10 50 50 50 25 75 50 Compton's Manual of Logarithmic Computations i2mo, Davis's Introduction to the Logic of Algebra. 8vo, * Dickson's College Algebra Large i2mo, * Introduction to the Theory of Algebraic Equations Large i2mo, Halsted's Elements of Geometry 8vo, Elementary Synthetic Geometry 8vo, Rational Geometry. (Shortly.') * Johnson's Three-place Logarithmic Tables: Vest-pocket size paper, 15 100 copies for 5 oo * Mounted on heavy cardboard, 8 X to inches, 25 10 copies for 2 oo Elementary Treatise on the Integral Calculus Small 8vo, i 50 Curve Tracing in Cartesian Co-ordinates i2mo, i oo Treatise on Ordinary and Partial Differential Equations Small 8vo, 3 50 Theory of Errors and the Method of Least Squares 12010, i 50 * Theoretical Mechanics i2mo, 3 oo Laplace's Philosophical Essay on Probabilities. (Truscott and Emory.) i2mo, 2 oo * Ludlow and Bass. Elements of Trigonometry and Logarithmic and Other Tables 8vo, 3 oo Trigonometry and Tables published separately Each, 2 oo Maurer's Technical Mechanics 8vo, 4 oo Merriman and Woodward's Higher Mathematics 8vo, 5 oo Merriman's Method of Least Squares 8vo, 2 oo Rice and Johnson's Elementary Treatise on the Differential Calculus . Sm., 8vo, 3 oo Differential and Integral Calculus. 2 vols. in one Ginall 8vo, 2 50 Wood's Elements of Co-ordinate Geometry 8vo, 2 oo Trigonometry: Analytical, Plane, and Spherical i2mo, i oo MECHANICAL ENGINEERING. MATERIALS OF ENGINEERING, STEAM-ENGINES AND BOILERS. Baldwin's Steam Heating for Buildings I2mo, 2 50 Barr's Kinematics of Machinery 8vo, 2 50 * Bartlett's Mechanical Drawing 8vo, 3 oo * " " " Abridged Ed 8vo, i 50 Benjamin's Wrinkles and Recipes i2mo, 2 oo Carpenter's Experimental Engineering 8vo, 6 oo Heating and Ventilating Buildings 8vo, 4 oo Gary's Smoke Suppression in Plants using Bituminous Coal. (In prep- aration.) Clerk's Gas and Oil Engine Small 8vo, 4 oo Coolidge's Manual of Drawing 8vo, paper, x oo Cromwell's Treatise on Toothed Gearing i2mo, i 50 Treatise on Belts and Pulieys 12010, i 50 Durley's Kinematics of Machines 8vo, 4 oo Flather's Dynamometers and the Measurement of Power 121110, 3 oo Rope Driving i2mo, 2 oo Gill's Gas and Fuel Analysis for Engineers I2mo, i 25 Hall's Car Lubrication i2mo, i oo Button's The Gas Engine 8vo, 5 oo Jones's Machine Design: Part I. Kinematics of Machinery 8vo, i 50 Part II. Form, Strength, and Proportions of Parts 8vo, 3 oo Kent's Mechanical Engineer's Pocket-book i6mo, morocco, 5 oo Kerr's Power and Power Transmission 8vo, 2 oo MacCord's Kinematics; or, Practical Mechanism 8vo, 5 oo Mechanical Drawing 4to, 4 oo Velocity Diagrams 8vo, i 50 11 Mahan's Industrial Drawing. (Thompson.) Svo, 3 5<> Poole's Calorific Power of Fuels 8vo, 3 oo Reid's Course in Mechanical Drawing 8vo. 2 oo Text-book of Mechanical Drawing and Elementary Machine Design. .8vo. 3 oo Richards's Compressed Air I2mo, i 50 Robinson's Principles of Mechanism 8vo, 3 oo Smith's Press-working of Metals 8vo, 3 oo Thurston's Treatise on Friction and Lost Work in Machinery and Miil Work 8vo, 300 Animal as a Machine and Prime Motor, and the Laws of Energetics . i2mo, x oo Warren's Elements of Machine Construction and Drawing 8