\ REESE LIBRARY UNIVERSITY OF CALIFORNIA. Class Works by tfje pame clut^or. QUALITATIVE CHEMICAL ANALYSIS. A Guide in the Practical Study of Chemistry and in the Work of Analysis. By SILAS H. DOUGLAS, M.A., and ALBERT B. PRESCOTT, M.D. With a Study of Oxidi- zation and Reduction by OTIS COE JOHNSON, M.A. Eighth edition. Octavo, cloth $3. SO OUTLINES OF PROXIMATE ORGANIC ANALY- sis: For the Identification, Separation, and Quanti- tative Determination of the more Commonly Occur- ring Organic Compounds. 12mo, cloth 1. 75 FIRS.T BOOK IN QUALITATIVE CHEMISTRY. Fourth edition. 12mo ... ..1.5O CRITICAL EXAMIKA TION OF ALCOHOLIC LIQUORS. A Manual of the Constituents of the Distilled Spirits and Fermented Liquors of Com- merce, and their Qualitative and Quantitative Deter- mination. 12mo, cloth 1 5O ORGANIC ANALYSIS: A MANUAL OF THE DESCRIPTIVE AND , ANALYTICAL CHEMISTRY OF CERTAIN CARBON COMPOUNDS IN COMMON USE. QUALITATIVE AND QUANTITATIVE ANALYSIS OF ORGANIC MATERIALS COMMERCIAL AND PHARMACEUTICAL ASSAYS; THE ESTIMATION OF IMPURITIES UNDER AUTHORIZED STANDARDS ; FORENSIC EXAMINATIONS FOR POISONS ; AND ELEMENTARY ORGANIC ANALYSIS. BY ALBEET B. PKESCOTT, PH.D., M.D., Director of the Chemical Laboratory in the University of Michigan, Author of " Outlines of Proximate Organic Analysis," " Qualitative Chemioal Analysis" etc. NEW YORK : D. VAN NOSTRAND, PUBLISHES, 23 MURRAY AND 27 WARREN STREET. 1887. COPYRIGHT, 1887, BY W. H. FARRINGTON. PREFACE. THE operator in chemical analysis requires for his direction a system of descriptive chemistry, to be as nearly complete as possible. In resorting to the hand-books of general chemistry for the record of physical and chemical constants the analyst is often disappointed. It belongs, tlieref ore, to analytical chemistry to furnish chemical descriptions with special precision, and this is a service promoting independent chemical work. -As a mere changeful body of directions, giving the latest expedients in methods, analytical chemistry cannot claim to have educational value. But as an operative introduction to the character and deportment of compounds, analysis becomes a logical mode of study, fruitful of important results. For certain common carbon compounds it has been under- taken to furnish in this work, first, systematic chemical description, and thereupon the methods of analytical procedure, qualitative, quantitative, and for proofs of purity, all with liberal citations of the authorities for convenience of further reading. In the references an order is observed as follows : (1) name of the con- tributor, (2) year of the contribution, (3) volume and page, first of original and then of contemporary publications. Respecting the assumed peculiarities of organic analysis, it more and more appears that the differences between inorganic and organic analysis have been greatly overstated, just as, at earlier periods, the distinction between inorganic and organic chemistry in general was overdrawn. With nearer acquaintance it is seen that the limits of error in determination of carbon compounds are by no means always wider than those in analysis of metallic bodies. vi PREFACE, If the author of this work have done anything at all to rescue the analytical chemistry of carbon compounds from a disjointed position in chemical literature, he will have gained enough of recompense. He desires to make thankful acknowledgment of the encouraging favor which has been extended to his " Outlines of Proximate Organic Analysis" since its issue in 1874. While his own promise of further publication has waited long for ful- filment, works of distinct value have opportunely appeared in different parts of the same field, and the flow of good contribu- tions has continued to increase everywhere. Organic analysis, as the determination of the unbroken compounds of carbon, no longer has an uncertain place in chemical learning. ALBERT B. PRESCOTT. UNIVERSITY OF MICHIGAN, ANN ARBOR, October, 1887. ORGANIC ANALYSIS. ABSINTHIN. Co Ho' 8 O 4 . II 2 O=350. The neutral princi- ple of the wormwood, Artemisia absinthium. Obtained by pre- cipitating the hot-water extract of the leaves and tops by tannic acid, drying the precipitate with litharge, and extracting with alcohol. The absinthin may be purified by filtering the alcoholic solution through animal charcoal, evaporating, and redissolving in ether. Absinthin solidifies from yellow drops to indistinct crystals, melting at 120 C., and decomposing at higher temperatures. It has an aromatic odor and a very bitter taste. It is almost in- soluble in cold water, slightly soluble in hot water, freely soluble in alcohol or ether ; soluble with a brown-red color in the alkali hydrates. The potassa solution, when acidified by hydro- chloric acid, exhibits a yellow-green play of colors. Concentrat- ed sulphuric acid dissolves it with brown color changing to freen-blue, and becoming dark blue on adding a very little water, luch water decolors it. If the alcoholic solution be treated with an equal volume of concentrated sulphuric acid a brown - red mixture results, and a violet color is obtained after adding a few drops of water. Froehde's reagent gives a brown color changing to green and violet (BACH, 1874). Absinthin precipi- tates mercurous nitrate dirty-yellow ; lead subacetate brown - yellow ; barium acetate brown. Soiling with dilute acids de- composes absinthin without producing a glucose. Fehling's so- lution is not reduced by it : ammoniacal silver nitrate solution is reduced, with the formation of a mirror. ACETIC ACID. Essigsaure. Acide acetique. C 2 H 4 O 2 = 60. Methyl-carboxyl, CH 3 . CO 2 H. Manufactured from alcohol or dilute alcoholic liquids by oxidation, or the acetous " fermen- tation," and from wood by destructive distillation yielding other products of value. It is produced in numerous chemical re- actions. Acetic acid is identified by its odor in the free state () and the more intense odor of its ethyl ester (d). The empyreuma of 8 ACETIC ACID. heated acetates is characteristic (d). It gives a distinctive color with ferric salts (d). It is separated by distillation, if necessary preceded by saponitication (e). From butyrates, by the insolu- bility of the barium acetate in alcohol (Butyric acid, e). It is estimated, as free acid, by acidimetry (f\ or gravimetric satura- tion ; as alkali acetate, by the alkalimetry of the ignited residue (f). In Acetate of Lime by distillation and by special methods (p. 11). Commercial Grades and Impurities, p. 14. Vinegar, its standards of strength, impurities, and special tests, p. 15. a. Absolute acetic acid (Glacial Acetic acid, Eisessig) below about 15 C. is a crystalline solid, forming transparent tabular masses, melting at 16.7 C. to a colorless liquid. An acid of 87 per cent, melts below C. ; of 62 per cent, at 24 C. The absolute acid boils at 118 C. It has, at 15 C., the sp. gr. 1.0607 (water at 4 C.) (MENDELEJEFF). . Acetic acid has a pure acidulous taste and a penetrating, vinegar-like odor. When concentrated it is an irritant to the skin or tongue, and should be diluted before tasting. c. Acetic acid is soluble in all proportions of water and alcohol ; the absolute acid is soluble in all proportions of ether, and acts as a solvent for various essential oils, resins, camphors, phenols, and metallic salts. Diluted with water acetic acid gives an acid reaction with litmus. The metallic normal acetates are soluble in water ; silver and mercurous acetates less freely than the others. Perfectly normal alkali acetates are neutral in re- action, as shown by phenol-phthalein or litmus, but potassium acetate is liable to be found alkaline, because slightly basic. Acetates in general lose acetic acid in hot solution, and in some instances by simple exposure, so that acetates exhale a percep- tible acetous odor, and gradually become basic. Non-alkali ace- tates, in solution, become slightly turbid, by formation of car- bonate, from carbon dioxide of the air. d. Ferric chloride or other ferric salt, added not in ex- cess to solution of acetates, causes a red color by formation of ferric acetate. On boiling, a yellow-brown precipitate of basic acetate of iron is obtained, resolved finally into nearly pure ferric hydrate. The red liquid, before heating, is not decolored by adding mercuric chloride solution, nor taken up by shaking with ether, both these negative results giving distinction from Thio- cyanic acid. The color is destroyed by adding sulphuric or hydrochloric acid a distinction from Meconic acid. By hot digestion with sulphuric acid and alcohol, ethyl acetate, or ACETIC ACID. 9 acetic ether, is formed, recognized by its penetrating, fragrant odor. This test is most efficient when the dry acetate, obtained from acidulous liquid by neutralizing with fixed alkali and eva- porating, is treated with an equal quantity of alcohol and a double quantity of sulphuric acid, and heated or distilled. The odor of other ethyl esters is liable to be mistaken for this. When dry acetates are strongly heated in a test-tube, carbon is separated and acetone, CgligO, is evolved, capable of recognition by its odor. By distillation of acetates with phosphoric or sulphuric acid, free acetic acid is obtained, with its characteristic odor. Acetic acid is a stable Compound, not oxidized by chromic acid nor by permanganates. e. Separations. Aqueous solutions of acetates, if kept slightly alkaline with fixed alkali, can be concentrated without loss oi acetic acid. The free acid distils very slow r ly, and its quantitative distillation requires thorough treatment. In distil- ling from acetates, phosphoric or sulphuric acid, or oxalic acid, is to be added, in some excess of the quantity needful to form nor- mal salts with all the bases present. To obtain all the acetic acid it is necessary to distil to dryness, adding water and repeating several times, until the distillate ceases to be acid to litmus. When various organic matters are present, it is therefore usually better to displace with phosphoric acid, avoiding the action of sulphuric acid in distilling to dryness. Care is to be taken that the phosphoric acid is strictly free from volatile acids, and that salts of volatile acids other than acetic are not present. If hy- drochloric acid or its salts are present, the addition of sufficient silver sulphate insures the retention of the chlorine. Further details respecting quantitative distillation are given under f. To obtain the acetic acid of basic acetates insoluble in water, it is preferable to transpose them to alkali acetate by digesting with hot solution of sodium carbonate, filtering, and exhausting with hot water. The same operation may with advantage pre- cede distillation in the case of lead acetate. Ethereal acetates, such as ethyl acetate, do not give up their acetic acid by displac- ing it with a non-volatile acid, but require first to be saponified by an alkali, when the alkali acetate is treated as before de- scribed. The saponification is effected by digesting with some excess of a solution of potassa in alcohol free from acetic acid, when all the alcohol may be removed by evaporation. Also, a volumetric estimation of the acetic acid of ethereal acetates may be readily and exactly made by saponifying with a known quan- tity of alcoholic potassa (see/*). io ACETIC ACID. f. Quantitative. In simple dilution with water, the spe- cific gravity of acetic acid, if closely taken, is a practicable indi- cation of percentage, according to tables of accepted authority, bearing in mind that acid of about 46 per cent, coincides in density with acid of 99 per cent. Even within the range to which it applies, the hydrometer is not exact enough, unless cor- rected in its reading by the analyst himself. Saturation methods of estimation are to be preferred, especially that by volumetric solution of fixed alkali. Phenol- phtnalein is the best indicator, but litmus will serve. Colored liquids may be diluted so as to show the phenol phthalein indication. If 6.000 grams of the acid mixture be taken, each c.c. of normal solution of alkali indi- cates 1 per cent, of C 2 H 4 O 2 , or real acid ; each c c. of decinor- mal alkali, 0.1 per cent. With dilute acetic acid, 2-LO grams may be taken, when c.c. -f- 4 = %. But, owing to the vaporization of aeetic acid, it is seldom advisable to take a stated weight for esti- mation. In a stoppered bottle, previously tared, pour 5 to 6 c.c. of the acid under estimation, stopper, take the weight, and titrate ; grams taken : 6.000 :: c.c. of normal alkali : # = per cent, real acid. Gravimetric methods of saturation may be employed. 1.000 gram of potassium bicarbonate (or 0.530 gram dry sodium car- bonate), taken in a tall beaker, may be neutralized with the acetic acid, the acid being added by weight from a small, light, lipped beaker, carrying a small glass rod with which to pour, adding at last drop by drop, and heating to expel the carbon dioxide. Then . 60 -f- grams of acid required = number per cent, of real acid present. Before testing the acetic acid, if much stronger than vinegar, it should be diluted, by weight, to from 2 to 15 times its own weight, so as not to be over 5 to 8$ strength. Then 60 X the factor of dilution (2 to 15)4-number grams of the diluted acid required = per cent, of real acid present. A gravi- metric method with barium carbonate is as follows : A weighed quantity of the acetic acid (sufficient to contain 0.120 to 0.180 gram absolute acetic acid) is digested with excess of well- washed, precipitated barium carbonate, the precipitate is filtered and ex- hausted with hot water, the filtrate is precipitated by dilute sul- phuric acid, with heating and washing as required in estimation of barium as sulphate, and the ignited barium sulphate weighed. (BaSO 4 : 2C 2 H 4 O 2 : : 232.8 : 120 : : 1 : 0.5156.) Grams of barium sulphate X 0.5156 = grams acetic acid absolute, in the quantity of acetic acid mixture under estimation. Free acids which form insoluble barium salts do not interfere. Oxalic acid will add by a trifling quantity to the result. Free acids which form soluble ACETATE OF LIME. u barium salts interfere altogether, but the addition of sufficient silver sulphate prevents interference of hydrochloric acid. Ace- tates and other salts of non-alkali metals precipitable by barium carbonate cannot be present. The acetic acid of alkali and alkaline earth salts may bo estimated by ignition of the dry salt, and titration of the result- ing alkali carbonate, or alkaline earth, with volumetric acid. Each c.c. of normal solution of acid used indicates 0.06 gram of absolute acetic acid. Of course the acetate taken for estimation in this way must be of neutral reaction ; or, if of alkaline reac- tion, its alkalinity (before ignition) must be estimated by titration, and the c.c. of acid so used must be deducted from the c.c. re- quired in titrating the ignited residue from an equal quantity of the salt. This plan of estimation is not among the more trust- worthy ones. The acetic acid of normal acetates of calcium, lead, and other non-alkali metals, is sometimes estimated by methods of determination of the metal. Valuation of "Acetate of Lime" Acetate of Lime (Pyro- lignate of Lime, Essigsauren Kalk, Holzessigsauren Kalk) is a product of the distillation of wood, used as a carrier of acetic acid toward concentration and purification. Its value lies in the amount of real acetic acid it contains. Three grades of it have been made the u gray," " brown," and " black " but the last- named grade is now seldom produced. Besides empyreumatic and carbonaceous matters, it is quite liable to contain butyrate, formate, and propionate ; * also magnesium salts ; and may con- tain chlorides. In the plan of wood distillation conducted at temperatures below charring, 3 Acetate of Sodium is usually manufactured instead of lime acetate, and no empyreumatic matter occurs. In the valuation of acetate of lime, the methods mostly in use have been based on (1) distillation of the acetic acid, and (2) the amount of soluble lime salts present. A volu- metric method (3) with evaporation of the acetic acid will also be given here. 3 The valuation should embrace an estimation of the moisture, and may present the proportion of magnesium ace- tate, if any be present. Samples are to be taken from every 1 Respecting the relation of these impurities to methods of estimation, LUCK, 1871 : Zeitsch. anal. Chem., 10, 184. 2 MABERY, 1883 : Am. Chem. Jour., 5, 256. 3 Respecting methods (1) and (2) STILLWELL and GLADDING, 1882 : Jour. Amtr. Chem. Soc., 4, 94. SEELY, 1872 : Am. Chem.. 2, 324 ; 3, 8. FRESE- NIUS, 1875 : Zeitsch. anal. Chem., 14, 172 ; 1866 : Ibid., 5, 315 ; 1874 : Ibid., 13, 153. H. ENDEMANN, 1876 : Am. Chem., 6, 294. A. A. BLAIR, 1885 : Am. Chem. Jour., 7, 26. 12 ACETIC ACID. fifth to tenth bag, fairly representing both large and small pieces, and inclosed in rubber bags or air-tight jars while sent and held for analysis. The moisture is always to be determined in a portion taken as soon as the sample is opened to the air. The sample is then pulverized and sifted in preparation for the ana- lysis. Then a prepared portion taken parallel with that sub jected to analysis is dried for estimation of its moisture, from which the percentage of acetic acid is at last corrected for mois- ture, whether for the figures on a dry basis, or on the air-dry basis of the primary samples (Stillwell and Gladding). Crystal- lized acetate of calcium contains water of crystallization and is efflorescent ; the product " acetate of lime " may gain or lose water in the air, but in paper or wood packages it is likely to lose. (1) By distillation of the acetic acid. The most trustworthy method. Of the prepared sample 5 grams are dissolved in 50 c.c. of water, at least 25 grams of glacial phosphoric acid are added, and the liquid distilled, repeatedly adding water, not per : mitting the liquid to be reduced to dryness, and persisting until the distillate ceases to have an acid reaction, or the retort to smell of acetic acid. According to Messrs. Stillwell and Glad- ding, if the retorted liquid be not reduced too low, not more than traces of hydrochloric acid can be carried over from chlo- rides, and the excess of phosphoric acid prevents production of insoluble calcium phosphate. All distillation of hydrochloric acid can be prevented by adding silver sulphate in the retort. Nitric acid must be tested for. f resenius (1875) and Endemann (1876) describe apparatus by which steam is introduced into the retort, in a current of regulated force, for continuing the distilla- tion. The total distillate is made to a desired definite volume, an aliquot part is measured out, phenol-phthalein added as an indicator, and titrated with standard solution of alkali (p. 10). (2) Methods depending on the quantity of soluble lime salts present. Of these methods the one given by Fresenius (1874, where cited) is one of the best, and is adapted to the assay of pure grades, free from acid empyreuma and from magnesium salt. Of the sample 5 grams are treated with about 150 c.c. of water in a quarter-liter "flask, 70 to 80 c.c. of normal solution of oxalic acid added, and the mixture diluted with water to the 250 c.c. mark. To compensate for the volume of the precipitate 2.1 c c. of water are added above the mark. After being shaken and standing for some time the precipitate is filtered out (through a dry filter). Of the filtrate 100 c.c. are titrated with normal ACETATE OF LIME. 13 solution of alkali for acid as acetic acid. Then another portion of 100 c.c. is treated with calcium acetate to precipitate all the excess of oxalic acid. The calcium oxalate precipitate is filtered out, washed, dried, ignited, weighed as calcium carbonate, and the indicated quantity of oxalic acid calculated into its equiva- lent of acetic acid. The total acid as acetic acid in ] 00 c.c., minus the oxalic acid as acetic acid in 100 c.c., equals the true acetic acid in 100 c.c. of filtrate that is, in f of the sample as- sayed (or in 2 grams). (3) A method proposed by GOBEL' is given as follows : For the titrations a solution of soda, of which 1000 c.c. = 100 grams absolute acetic acid ; a solution of phosphoric acid which titrates to phenol-phthalein of a strength equal to the soda solution ; and a solution of hydrochloric acid which titrates to litmus of a strength equal to the soda solution. A weighed quantity of the acetate under assay is treated with some measured quantity taken as an excess of the standard phosphoric acid ; the mixture evapo- rated to dry ness ; the residue treated with water and evaporated again, and until the odor of acetic acid is no longer obtained ; the residue then treated with water and the mixture titrated for excess of phosphoric acid, with the standard soda, using phenol- phthalein, and noting the result in equivalent of acetic acid. Subtracting this figure from that for the acetic acid represented by the phosphoric acid first added, the difference is the figure for the acetic acid in the acetate taken subject, however, to cor- rection for free lime and lime carbonate in acetate of lime taken for assay. By titrating a weighed portion with the standard hydrochloric acid, adding an excess, expelling carbon dioxide, and bringing back to the neutral tint of litmus with standard soda, the acetic acid equivalent to the unsaturated earthy bases is found, and deducted for the correction. A rapid method of assay, which has been much used, but is apt to give figures too high, is carried as follows : A weighed quantity of the acetate of lime is supersaturated with a known quantity of sodium carbonate in solution ; the precipitate filtered out and washed ; and the alkali of the total filtrate estimated as sodium carbonate by titration of an aliquot part. The loss of sodium carbonate due to the removal of acetic acid (and acid empyreuma) in the precipitation is calculated into acetic acid, ancl figured upon the quantity of acetate of lime taken. BLAIR (1885, where cited) obviates the difficulty of the color of the 1 1884 : Repert f. anal. Chem., 3, 374 ; Zeitsch. anal Chem., 23, 264. 14 ACETIC ACID. solution by filtering it through animal charcoal, and then obtains good results by this method. g. Commercial Grades and Common Impurities. The strengths of acetic acid have been designated by a " No.," alto- gether different from vinegar numbers, but probably originating, under the British excise system, in the number of parts of four per cent, vinegar producible by dilution. 1 Thus No. 8 acid is that which diluted to eight parts will have about four per cent, strength. The two grades numbered on this system, in this coun- try, are " No. 8 " and " No. 12." Interpreted according to original intent, therefore, No. 8 should be of 32 per cent., and No. 12 of 48 per cent, strength. Dr. Squibb finds that the best qualities of No. 8 acid actually prove of near 30$ strength, bearing label mark of s.g. 1.040 ; the poorer qualities of No. 8 are near 25$ strength, and issued without a gravity mark. No. 12 acid is less common, and often runs from 38 to 40 per cent, of real acid. The strengths of vinegar numbers refer, in the British custom, to the number of grains of dried sodium carbonate neutralized by one Imperial fluid-ounce. fNa 2 CO 3 : C 2 H 4 O 2 ::53 : 60::1 . : 1.132. The number x 1.132 grains absolute acid per fluid-ounce (of grains 437.5 X s.g.) The number X 0.259 = grams absolute acid in 100 c.c. vine- gar. In this country vinegar numbers have been grains of sodium bicarbonate neutralized by one fluid -ounce, wine mea- sure. NaHCO 3 : C 2 H 4 O 2 : : 84 : 60 : : 1 : 0.7143. The number x 0.7143 = grains absolute acid per fluid-ounce (of grains 455.7 X s.g.) The number X 0.1567 = grams absolute acid in 100 c.c. vinegar. Much of the " Glacial Acetic Acid " of commerce is not over 75 per cent., of real acid (SQUIBB). It can easily be furnished of 99+ per" cent., as required by U. S. Ph. Of impurities in ordinary acetic acid, the more common are mineral acids, especially hydrochloric, empyreumatic bodies, and metallic salts. Empyreuma, and other foreign bodies having odor or taste, are recognized by these senses after neutralizing with potassa or soda. " When diluted with five volumes of distilled water, the color caused by the addition of a few drops of test-solution of permanganate of potassium should not be sensibly changed by standing five minutes at the ordinary tem- perature (absence of empyreumatic substances)." U. S. Ph. According to Dr. Squibb,' when 1 c.c. of the acid, diluted with 5 1 SQUIBB, 1883 : Ephemeris, i, 258. * 1883 : Ephemeris, i, 260. VINEGAR. 15 c.c. distilled water, is treated with 3 drops of decinormal solu- tion of permanganate, in comparison with the same addition to the distilled water, if the color does " not become fully brown " within ten minutes, it is u a very good acid indeed," but the glacial acid " should stand this modification of the permanga- nate test for more than an hour." In vinegar the most common impurities are (1) free mineral acids, and (2) empyreumatic bodies (in " wood vinegar "). Be- sides, various made-up vinegars, and forms of diluted acetic acid, are substituted for or added, to cider-vinegar. The absence of free mineral acid is shown by an alkaline re- action of the ash. Let the residue be carefully ignited and the cold ash touched with wet litmus-paper. The residue can be ignited on the loop of platinum wire. All natural vinegars con- tain some alkali acetate, and in absence of mineral acids will give an alkaline reaction in the ash. If the vinegar be a mere diluted acetic acid, as a " white vinegar," a few drops of decinormal solution of fixed alkali are to be added before the evaporation, when a neutral reaction of the ash indicates free mineral acid. To estimate the quantity of free mineral acid, take 50 grams of the vinegar, add of decinormal alkali from the burette enough to surely neutralize all free mineral acid, still leaving the reaction acidulous, evaporate, ignite with care against loss, and titrate back with decinormal acid. Then c.c. T ^ alkali c.c. -^ acid X 2x0.0049 = per cent, of free mineral acid, as sulphuric acid. Using the factor 0.00364, the statement is obtained for hydro- chloric acid, etc. Free sulphuric acid, in absence of chlorides, may be separated and determined as follows : 100 c.c. are evapo- rated on the water-bath nearly to dryness, treated with about 100 c.c. of alcohol, the mixture filtered, the alcohol evaporated off, and the residue diluted for the gravimetric estimation of the sulphuric acid in it, by precipitation with barium chloride. If chlorides be present in the vinegar, it is necessary to add silver sulphate before adding the alcohol, when both the free sulphuric and hydrochloric acids of the vinegar are estimated as sulphuric acid. It must be remembered that sulphates and chlorides are liable to be present in legitimate vinegars, and the simple reactions with silver and barium, as prescribed for acetic acid, are not applicable in tests of vinegars in general. But, according to DAVENPORT/ "in a pure cider vinegar, nitrate of silver, nitrate 1 " Report of Inspector of Vinegar of the City of Boston," 1884, p. 4 ; of Inspector of Milk of the same, 1885, p. 10. 16 ACETIC ACID. of barium, or oxalate of ammonium added after an excess of am- monia water, will neither of them give more than the slightest perceptible reaction." Also, " a drop of it in a loop of platinum wire, when ignited in a Bunsen lamp-flame, gives a pure potash flame without any yellow soda rays visible." "The addition of any practical amount of a commercial acetic acid to tone up the strength will give another color to the flame." Cider- vinegars yield a residue " always soft, viscid, mucilaginous, of apple flavor, somewhat acid and astringent to the taste." "If any corn glucose is present, the residue, when ignited in the platinum loop, will emit the characteristic odor of burning corn ; and if the glucose was manufactured with the commercial sulphuric acid derived from copper-pyrites, it will, as the last spark glows through the carbonized mass, emit the familiar garlic odor of arsenic." The percentage of solids in cider-vinegar, by weight of residue, is generally required to be as much as 1.5 per cent. Dr. DAVENPOKT (1885) recommends that the legal limit be 2 per cent. " When 20 grams of the vinegar are mixed with 0.5 c.c. of barium nitrate test-solution (1 to 19) and 1 c.c. decinormal silver nitrate solution, the filtrate from the mixture should give no re- action for chlorine or sulphuric acid. When two volumes are added to one volume of sulphuric acid and then one volume of ferrous sulphate solution poured over, no brown zone should appear between the layers. The evaporation-residue from 100 grams should not exceed 1. 5 grams. The residue should not have a sharp taste, and its ash should have an alkaline reaction." Ph. Germ. The required strength of vinegars is given by IL S. Ph. of 1870 at 4.6$; Br. Ph., 5.41#; Ph. Germ., 6^; the "proof vinegar " of British Excise, 6$, or English " No. 24." In exe- cution of the British law against adulterations of foods, the minimum limit of strength has been held at 3$. For " cider- vinegar," the limit recommended by Dr. Davenport, in the Bos- ton City inspection, is 5 per cent, of real acetic acid ; and the lowest limit there proposed, 4J per cent. In New York City the legal requirement, well enforced (1886), is 4j per cent, of acetic acid as a minimum for all vinegars, and 2 per cent, of solids for cider- vinegars. The following is the form of Inspector's Record and Analyst's Report, under the regulations of the city of Boston, 1886 : " Vinegar : Date, ; Time, ; Proprietor's name, - ; No. , Street ; Sold by ; Price paid, ; Quan- tity, pint ; Wholesaler's name, - ; Price paid ditto, ; ACONITE ALKALOIDS. 17 .LUSlrlCl, , V>lUtu, , 1 JUILC wine, , . /^ol/^inrn (^nlnr * T^T*PP apirl ' ACIDS OF THE FATTY SERIES, CnH 2 nO 3 . See FATS. ACONITE ALKALOIDS. Natural alkaloids of plants of the genus Aconite (Ranunculacese), and artificial products of these alkaloids represented by Aconitine, C 33 H 43 NO 13 = 65 (WRIGHT, 1877). CONTENTS : Chemical constitution ; saponification changes ; list of alka- loids witli rational formulae ; dehydration changes ; list of alkaloids with phy- siological effects; sources; yield. Analytical outline for crystallizable and for amorphous alkaloids of aconite : a, heat-reactions of each ; b, taste and phy- siological effects ; c, solubilities ; d, qualitative tests, with limits ; e, separa- tion in general, from aconite root, fivm animal tissues; /, quantitative methods, gravimetric, volumetric, of produced benzoic acid ; g, commercial grades and values. Chemical constitution and character. It has been established by Wright and his co-workers ' that the crystallizable alkaloids of the aconite group are salts, or esters, of benzoic acid (or a derivative of this acid), and are readily saponifiable by action of alkalies or strong acids, to some extent even by water with heat. And the saponitication results in the removal of either benzoic acid or a derivative of benzoic acid, and the formation of amorphous alkaloids in place of the crystallizable alkaloids sapo- nified. The tendency of aconite alkaloids to become amorphous, with diminished physiological activity, is explained by saponifica- tion. Their liability to another and less obvious class of chemi- cal changes, leaving them still crystallizable and with little loss of physiological activity, is shown by the proof that, by action of strong acids, they suffer dehydration and form apo alkaloids. That is to say, alkalies, with more or less readiness, and even hot digestion with water, cause saponification; and strong mineral acids, even concentrated organic acids in a degree, cause both saponification and dehydration to apo-compounds. a Various 1 C. R. A. WRIGHT, in part with A. P. LUFF, and with A. E. MENKE, 1877- 1879 : Jour. Chem. Soe., 31, 143 ; 33, 151, 318; 35, 387, 399. Phar. Jour. Trans. [3] 8, 164-167. Further, MANDELIN, 1885 : Archiv d. Phar. [3] 26, 97, 129, 161 ; Phar. Jour. Trans. [3] 15. JUERGENS, 1885 : Phar. Zeitsch. Russland. 2 It is a noteworthy correspondence that three active alkaloidal agencies of intense physiological power, in ey tensive medicinal use at present, Aconitine, 1 8 ACONITE ALKALOIDS. other transformations are brought about by agents not so com- monly employed in processes of separation as are the alkalies and acids. The following equations show the changes of saponification, by alkalies or acids, upon four of the crystallizable alkaloids of the aconites according to Wright : 1 Crystallizable alkaloids. Amorphous alkaloids. Benzoic acid. C 33 H 43 NO 12 (aconitine)+H 2 O==C 26 H 39 NO n (aconine)+C 7 H e O 2 C3iH 45 NO 10 (picraconitine)+H 2 O =C 24 H 41 NO 9 (picraconine+C 7 H 6 O 2 C 66 H 88 N 2 O 21 (japaconitine)+3H O = 2C 26 H 41 lSr0 10 (japaconine)+2C 7 H 6 2 C 36 H 49 NO 12 (pseudaconitine)-pH 2 O Dim ethylprotocatechuic acid. C 27 H 41 NO 9 (pseudaconine )-f C 9 H 10 O 4 The rational formulae 2 of these alkaloids include the an-, hydride of benzoic acid, or of one of its derivatives, in the crystallizable members of the group ; and include hydroxyl instead of the acid anhydride in the amorphous members of the group ^WEIGHT) ; as follows : Aconitine, C 33 H 43 1TO 12 =C 26 H 35 NO 7 (OH) 3 . . (C 7 H 5 O) Aconine, C 26 H 39 KO n =C 26 H 35 NO 7 (OH) 3 . OH Japaconitine, C 66 H 88 N 2 O 2] =2 [Co 6 H 39 lS T O 7 O . O . (C 7 H 5 O)] O Japaconine, C 26 II 41 NO 10 =C 26 H 3 jNO 7 O . (OH) Pseudaconitine, 3 36 H 49 NO 12 =C 97 H 37 NO 5 (OH) 3 . . (C 9 II 9 O 3 ) Pseudaconine, C 27 H 41 NO 9 =C 27 H 37 Ts"O 5 (OH) 3 . OH. Atropine, and Cocaine, agree in being saponifiable alkaloids easily giving up either benzoic acid or some near derivative of benzoic acid. (Atropine : KRAUT, 1865. Cocaine : LOSSEN, 1865. Aconitine : WRIGHT, 1877.) Among other saponifiable alkaloids, yielding acids of the aromatic group, are piperine, and certain veratrum alkaloids. 1 In saponification by alkali, the benzoic acid or its derivative is left in com- bination with the alkali, from which it is obtained by acidulation. In saponi- fication by acid the amorphous alkaloid is obtained in salt of the acid. 2 WRIGHT (1879), in his last contribution upon the aconite alkaloids, strongly inferred the existence of a "hypothetical parent-base, C33H 47 NOi 2 " =C a 6H3 9 N07.(OH)3.O.(C 7 H50). JUERGENS (1885, where before quoted), by a modified process of extraction from the root, and thorough purification, ob- tained aconitine which, in elementary analysis, gave him numbers for C 33 H47NOi2. The alkaloid gave the intense numbing sensation upon the tongue, without a recognizable bitter taste. 3 MANDELIN (1885), by investigations (without elementary analysis), con- cluded that aconine and pseudaconine are the same, so that, in his view, aconi- tine and pseudaconitine differ only by their acidulous radicals as found by Wright. ACONITE ALKALOIDS. The amorphous alkaloids are found in the plant, as well as obtained by alteration of the crystallizable alkaloids during sepa- ration from the plant. The changes of dehydration to apo-alkaloids, by action of acids, is shown by the following comparisons of rational for- mulae : Aconitine, C 33 H 43 NO 12 =Co 6 H 35 NO 7 (OH) 3 . . (C 7 H 5 O) Apo-aconitine, C 33 H 41 JS r O 11 =C 26 H 35 NO 7 (OH)O . O . (C 7 H 5 0) Aconine, C 26 H 39 NO n ^C 26 H 35 NO 7 (OH) 3 . OH Apo-aconine, C 26 H 37 lSrO 10 =C 26 H 35 NO 7 (OH) 2 O Pseudaconitine, C 36 H 49 NO 12 =C 27 H 37 NO 5 (OH) 3 . 0. (C 9 H 9 O 3 ) Apo pseudaconitine, C 36 H 47 NO n =C 27 H 37 N0 5 (OH)0 . . (C 9 H 9 3 ) The natural alkaloid, japaconitine, has the constitution of a sesqui-apo- derivative. Chief Sources of the Natural Aconite Alkaloids. A. Napellus* root. "Aco- Aconitine. nite" of U. S. Ph. and Aconine. Ph. Germ. Pseudaconitine | in small propor- Pseudaconine \ tion, if at all. A. ferox, root. " Indian Aconite " " Nepal Aco- nite." Bish, or Bikh. " Himalaya root." Japanese aconite, root. A. lycoctonum} root. A. anthora, root. A. paniculatum, root. Pseudaconitine. Pseudaconine. Aconitine ) T,.I Aconine } VM 7 llttle> Japaconitine. Japaconine. Other alkaloids. Aconitine. Pseudaconitine. Amorph. alkaloids. Pseudaconitine. Amorph. alkaloids. Picraconitine. 1 A report of alkaloids from this getic effect like curare DRAGENDORFF plant, amorphous, and having an ener- & SPOHN, 1884. 2O ACONITE ALKALOIDS. The chief Aconite Alkaloids : Synonyms, Crystallization, and Activity. Name. Synonyms. Formula. Crystallization. Physiolog. effect. Aconitine. Dryst. aconitine. Napaconitine. C 33 H 43 N0 12 Crystallizable, when free, as well as in salts. Of typical aco- nite activi- ty. Pseudaconitine. Napelline. Feraconitine. Acraconitine. English aeon. C 36 H 49 N0 12 Base and its salts crys- tallize with difficulty. Approaches to or equals the activity of aconitine. Japaconitine. Cryst. alkaloid of Japanese root. OeeHgsNaOai Crystallizable both free and in salts. Closely resem- bles aconi- tine in pro- perties and effects. Aconine. Amorphous aco- nitine. A pro- duct of aconi- tine, by alkalies or acids. C 26 H 39 NOn Amorphous, both free and in salts. Of far low- er activity than aconi- tine. Bitter. Pseudaconine. Amorphous aco- nitine. A pro- duct of pseud- aconitine, by alkalies. C 27 H 41 N0 9 Amorphous, free or com- bined. Of far low- er activity than aconi- tine. Bitter. Japaconine. Amorphous alka- loid of Jap. aconite. Pro- duct of Japaco- nitine. C 26 H 41 N0 10 Amorphous, free or com- bined. Closely resem- bles aconine in properties and effects. Picraconitine. Inactive, bitter al- kaloid of A. pa- niculatum and other species. C 3 iH 45 NOio Base cryst. with diffi- culty. Salts crystallize well. Bitter. Not poisonous. Picracouine. Amorphous pro- duct of picraco- nitine. C 24 H 41 N0 9 Amorphous. Bitter. Not poisonous. Apo-aconitine. Product of aconi- tine, by action pf acids. C 33 H 41 NOn Crystallizable. Of the same activity as aconitine. Corresponding apo-derivatives, by action of acids on Pseudaconitine, Aconine, etc. (See p. 19.) ACONITE ALKALOIDS. 21 For medicinal uses the U. S. Ph. and Ph. Germ, admit only the tuberous root of A. Napellus; the Br. Ph., also U. S. Ph. of 1870, admit both " root " and leaf of A. ]S T apellus ; the Ph. Fran, authorizes the use of root and leaf of A. Napellus and A. ferox. It is understood that both Japanese aconite root 1 and root of A. ferox are largely used for the manufacture of medicinal alkaloid "aconitine." A. Sterkeanuni contains poisonous alkaloids. Yield of natural Aconite Alkaloids. WEIGHT obtained, in 1876, from A. Napellus only 0.03 per cent, of pure aconitine, and only 0.07 per cent, of total alkaloids free from other matter. Again, from Japanese aconite roots 0.18 per cent, of mixed al- kaloids. JUEKGENS (1885) obtained, by a modified Duquesnel's process, of thoroughly purified aconitine (for elementary analy- sis) 0.02 per cent. By chemical assays (1883) LABORDE and DUQUESNEL found in A. Napellus root, of " crystalline alkaloids " from 0.05 to 0.40 per cent., averaging 0.15 per cent. ; of "amor- phous, insoluble substance " having an effect like aconitine in kind, " a few " tenths per cent. ; and of " amorphous, soluble, bit- ter substance," about 1.5 per cent. ZraoFFSKi, 2 working by volu- metric estimation with Mayer's solution (probably an inexact measure of total aconite alkaloids) in A. Napellus and other species, from the fresh leaf (calculated to basis of dry material) 0.73 to 1.38 per cent, total alkaloid ; from the fresh stalks, 0.25 to 0.90 per cent. ; and from the fresh flowers, 1.51, 1.65, and 5.52 (!) per cent, total alkaloids. HAGEB (1863) reported find- ing in the best commercial root of A. Napellus from 0.64 to 1.25 per cent, [total alkaloids]. SQUIBB (1882) found the leaf of A. Napellus to have only about one-ninth of the physiological effect of the same quantity of the root. CULLAMORE (1884) found the action of A. ferox to be more intense in degree than that of an equal quantity of A. Kapellus. The " aconitine " of the market may contain any mixture of the aconite alkaloids frequently aconitine, japaconitine, pseud- aconitine, and the wholly amorphous alkaloids. Systematic phy- siological assay of four commercial grades of " aconitine," by Dr. SQUIBB in 1882, in comparison with good powdered aconite root, gave the following results : (1) Of unknown make had only the 1 >hy siological potency of the root ; (2) " Ordinary," 8 times the strength of the same weight of the root ; (3) Pseudaconitine, 83 times the power of the root ; (4) " Crystallized," 111 times the 1 Respecting Japanese and Chinese Aconites, see LANGGARD, also WASO- vicz, 1880 : Archiv d. Phar., 14, 217, and 15, 161 ; Phar. Jour. Trans., [3] 10, 149, 1020 ; Proc. Am. Pharm., 29, 170-182. 1 DragendorfTs * VVtTthbestiinmung," 1874, p. 13. 22 ACONITE ALKALOIDS. effect of the root. If we accept Wright's analyses, first above given, the total aconite alkaloids should have from 500 to 1400 times the potency of the same weight of root. Further, Dr. Squibb found that the article (4) was a nitrate containing not more than 80.7 per cent, of hydra ted alkaloid. Aconitine was dropped in the last revision of the U. S. Ph. and in the last re- vision of the Ph. Germ. It is retained by Br. Ph. and Ph. Fran. THE CRYSTALLIZABLE ACONITE ALKALOIDS are identified by their organoleptic effect (&), the agreement of their precipitations (d 9 p. 25) and solubilities (y physiological assay, under J, p. 23. For commercial grades and values, f; sources, p. 19. a. Aconitine crystallizes anhydrous in rhombic or hexa- gonal tables, appearing in snow-white flakes; and its salts crystal- lize well. Japaconitine crystallizes well, both free and in its salts. Pseudaconitine and its salts do not crystallize without very careful treatment ; from ether, or better a mixture of ether with petroleum benzin, it forms needles or sandy crystals, with 1 aq., but unless the concentration be extremely slow only cau- liflower-like efflorescence or a varnish layer will lie obtained. The nitrate crystallizes when treated with care. Pier aconi tine crystallizes with difficulty as a base ; its salts easily form good crystals. A conine,pseudaconine, and japaconine, with their salts, are white, powdery solids, strictly uncrystallizable. The apo- alkaloids agree in crystallization with the aconite alkaloids from ACONITE ALKALOIDS. 23 which they are formed apo-aconitine being crystallizable, and * -i r*\i T* T^l t 1 // * ^* alkaloid) is usually amorphous, often colored, sometimes in thin, partly effloresced plates, sometimes in large needles. Aconitine melts at 18-A C. (WRIGHT) ; pseudaconitine loses water of crystallization at 80 C., melts at 105 C., and de- composes at about 130 C. ; japaconitine melts at 184 to 186 C. ; aconine melts at 130 C. ; pseudaconine at 100 C. ; picraconitine does not melt on the water-bath; apo-aconitine melts at 185 C. These alkaloids all preserve a constant weight on the water-bath ; when ignited they burn awav slowly. As to sublimation, and microscopic identification of the sublimate, see HELWIG (1864) ' and BLYTH (1878). a J. Aoomtine, in solutions dilute enough to be safe for the trial, causes a tingling and characteristic numbness of the lip and tongue and pharynx, commencing after a delay of from a minute to a quarter of an hour, according to the extent of dilu- tion. Dr. SQUIBB 3 found that 0.006 gram (0.1 grain) of good aconite root, in a solution of 3.7 c.c., or 1 fluid-drachm (of its soluble constituents), held in the anterior part of the mouth (pre- viously rinsed) for sixty seconds, and then discharged, gave the tingling sensation (as a rule), commencing within 15 minutes and then continuing for a quarter or a half an hour. When the same volume of solution was made to contain the soluble part of 0.02 gram (0.3 grain) of the root, the tingling began in 5 to 10 minutes, increased for a time, and continued in all about 1.5 hours. If we accept the percentages of total alkaloid reported by Wright (0.07 to 0.18$), and grant the entire alkaloid to have the full activity of aconitine, then, on the foregoing data, 4 from 0.000004 to 0.00001 gram (0.00006 to 0.00015 grain) of this alka- loid in a fluid-drachm of solution held one minute in the mouth causes lip-tingling within a quarter of an hour. 5 But this de- 1 Zeitsch. anal. Chem., 3, 52. 2 Jour. Chem. Soc., 33, 316. 3 1882 : Ephemeris, I, 125. 4 It appears safe to assume that the specific action of the aconites is repre- sented by their alkaloids. FLEMING found aconitic acid to have little effect upon rabbits when subcutaneously injected. TORSELLINI (1884) reported aconi- tic acid to have a paralyzing effect on the heart of a frog. 5 " The physiological action of aconitine is excessively energetic, so much so as to render'working with it a matter of considerable pain and difficulty, unless great care be taken in the manipulation, and more especially in avoid- ing the dust of the crystals of the base or its salts. A minute fragment, too small to be seen, if accidentally blown into the eye, sets up Iho most painful 24 ACONITE ALKALOIDS. gree of potency is not attained by commercial "aconitine." Aconitine is commonly described as having a bitter taste, which, in proportion to its special activity, is not at all pronounced. JUERGENS (1885) found carefully-purified aconitine to have no recognizable bitterness. The bitterness of commercial " aconi- tine " is in inverse ratio to its purity, in freedom from amor- phous aconite alkaloids. The medicinal dose of absolute aconitine or pseudaconitineim a man is placed by MANDELIN (1885) at 0.0001 gram (-$%-$ grain) in a single dose, and 0.0005 ( T ^ grain) during 24 hours. Of DuquesnePs "aconitine" SEQUIN (1878) gave 0.0005 gram (TTO g ram ) as a single full dose ; and the same quantity of Hot- tet's " aconitine " was given as a single maximum dose by GTJB- LER (1880). Of commercial crystallized "aconitine " of unknown strength, current authorities limit the first (or trial) dose at about 0.0002 gram (^ s grain), but this is double the dose of absolute aconitine declared by Mandelin, as above. The smallest fatal dose of absolute aconitine, or pseudaconitine, for a man is placed by MANDELIN (1885) at 0.003 gram (near -^ grain) ; for warm- blooded animals, 0.00005 to 0.000075 gram per kilogram of body- weight ; for frogs, 0.0012 to 0.0024 gram per kilogram of body- weight. BLYTH (1884) deduces that, of French aconitine or Morson's aconitine, by the mouth, the least fatal dose for a man is 0.002 gram (-fa grain), equal to 0.000028 gram per kilogram of body-weight ; for the cat 0.000075 to 0.00009 gram per kilo- gram of body-weight. With the frog (DRAGENDORFF) 0.002 gram [aconite alkaloid] causes paralysis of the hind legs in a few minutes. Dilatation of the pupil is not a constant effect of aconitine, but usually occurs in some stages of its action. Pseudaconitine, indefinitely represented by the old " napel- line," undoubtedly has nearly or quite the same physiological effect as aconitine. CULLAMORE (1884) found the action of Aconitum ferox root to be similar in kind to action of A. JSTa- pellus. The wholly amorphous aconite alkaloids, aconine and pseud- aconine, have but in a very low degree the specific activity of aconitine. HUSEMANN (1884 : Phar. Zeitung] found aconine to have a toxic effect on frogs and mice, an effect 300 to 400 times less than that of aconitine. Wright stated of aconine and of irritation and lachrymation, lasting for hours ; whilst similar particles, if in- haled, produce great bronchial irritation, or profuse sneezing, and considerable catarrh or ' sore throat,' according to the part where they lodge." (J. 11. A. WRIGHT, first report. ACONITE ALKALOIDS. 25 pseudaconiue that it is of extremely bitter taste, ~but does not pro- duce the slightest lip-tingling. The apo-alkaloids of aconite have the effect of the alkaloids from which they are derived. Apo-aconitine has the full physio- logical activity, and apo-aconine is an inactive bitter. " Pier aconitine is very bitter, and quite destitute of the spe- cific potency of aconitine. Aconitine, and its allied bases, have a decided alkaline re- action, and neutralize acids perfectly, forming salts more stable than the free alkaloids. The nitrate is a favorite salt for crystal- lization. c. Aconitine is very little soluble in cold water (in 726 parts, JUERGENS, 1885), but dissolves in hot water, and in alcohol (24 parts of 90$ alcohol), ether, benzene (sparingly when cold), freely soluble in chloroform, soluble in amylalcohol (DRAGENDORFF), does not dissolve in petroleum benzin or carbon disulphide. It requires 2806 parts of petroleum benzin for solution (JUERGENS). It is not dissolved from aqueous solutions of its salts by ether, or chloroform, or benzene. Pseudaconitine is sparingly soluble in water, more freely soluble in alcohol and in ether than aconi- tine is (WRIGHT). Japaconitine is soluble in alcohol and in ether; picraconitine is very sparingly soluble in water. A co- nine is freely soluble in water, alcohol, or chloroform, almost in- soluble in ether, especially when free from alcohol (WRIGHT). Pseudaconine dissolves in water, or alcohol, or ether (WRIGHT). Apo-aconitine and apo-aconine dissolve in ether. d. The most delicate and distinctive test for the active al- kaloids of the aconites is the physiological test for lip tingling, described on p. 23. Aconite alkaloids namely, aconitine and pseudaconitine and their amorphous products, aconine and pseudaconine, are precipi- tated, from their nearly neutral solutions in hydrochloric acid, as follows (^WRIGHT) : by " bromine water, iodine dissolved in potassium iodide, tannin, gold chloride, mercuric iodide dis- solved in potassium iodide, mercuric bromide in potassium bro- mide, and mercuric chloride. These precipitates dissolve on more or less largely diluting the fluids, the aconine precipitates being more soluble than the corresponding pseudaconine ones, which again, save in the case of tannin, are markedly more soluble than those of aconitine or pseudaconitine. Other things being equal, the mercuric chloride precipitates are more soluble than those formed with mercuric bromide, which are more solu- ble than those thrown down by mercuric iodide. Aconine is 26 ACONITE ALKALOIDS. not precipitated by sodium carbonate or ammonia, save when the solution is evaporated almost to dry ness, so that an oily liquid separates along with the solid sodium or ammonium salt ; pseud- aconine behaves similarly, whilst aconitine and pseudaconitine are but sparingly soluble in excess of these reagents. Strong caustic potash precipitates all four bases, the aconitine and pseud- aconine precipitates being only sparingly soluble in excess, the pseudaconine being much more readily soluble on diluting the fluid, and aconine being precipitated only in very concentrated solutions. Platinic chloride throws down precipitates only with strong solutions, especially with pseudaconine and aconine, the precipitates in all cases dissolving readily on dilution. It is noticeable that picraconitine is scarcely distinguishable from aconitine in these reactions, excepting that with sodium car- bonate and ammonia it is precipitated much less readily, the precipitate being formed only in concentrated solutions, and dis- solving readily on dilution." Further (WEIGHT), the amorphous alkaloids, aconine and pseudaconine, are distinguished from the crystallizable aconite alkaloids by greater reducing powers reducing silver (slowly) from hot solution of silver nitrate or of ammoniacal silver ni- trate ; and gold from the gold chloride precipitate, on standing. Aconine reduces Fehling's solution on boiling, a distinction from pseudaconine, which does not. Both crystallizable and amorphous aconite alkaloids (like the ptomains) promptly reduce ferricyanide of potassium, as shown by a drop of ferric salt solution. Limits. The precipitation by iodine in potassium iodide is distinct (on a glass slide) in one grain of a solution of the al- kaloid in 50,000 times its weight of water (WORMLEY). With the gold chloride, one grain of a solution of the alkaloid in 5,000 parts yields in a little time a quite fair precipitate ; diluted to 20,000 parts, after some time a just perceptible turbidity. With bromine in hydrobromic acid, one grain of a solution of one part of the alkaloid in 10,000 parts of water gives, a quite fair precipitate (WORMLEY). The limit of the precipitation by potas- sium mercuric iodide (DRAGENDORFF) is about 0.0009 gram in 1 c.c. of acidified solution, acidulation diminishing the solubility of the precipitate. Phosphomolybdic acid gives a yellow pre- cipitate, changing to blue on standing, and dissolving blue in ammonia 0.00007 gram alkaloid in 1 c.c. water acidulated with sulphuric acid giving a distinct precipitate after half an hour (DRAGENDORFF)/ 1 A test for completely purified aconitine is given by JUERGENS (1885) as follows : The particle of solid alkaloid, or residue of its solution, on a glass ACONITE ALKALOIDS. 27 The color reactions by acids, Froehde's reagent, etc., are so widely varied by alterations and differences (impurities) of the aconite alkaloids that no dependence can be placed upon them, unless the results are interpreted by results of control tests made by the analyst upon strictly parallel aconite products. 1 6m Separations. Aconite alkaloids are not vaporized, but are very slowly saponified, by concentration of their aqueous so- lutions on the water-bath. Such concentration should, if pos- sible, be done in neutral solution, and action of alkalies is gene- rally more destructive than action of acids. Dr. SQUIBB stated (1882) that the attenuated solutions of aconitine, and those of fluid extract of aconite, diminished in strength, shown by physio- logical action, after the second day ; and in four days, the weather being warm, they became quite inert, the growth of cryptogams keeping pace with the loss of strength. -^-Aconite alkaloids can be shaken out or extracted from slightly alkaline (not from aci- dulous), cold, aqueous solutions, by ether, chloroform, etc., ac- cording to the solubilities in these respective liquids, given on p. 25. And from solution in these liquids acidulated water takes up the alkaloids In separation from aconite root, the process of Duquesnel, modified by Wright and otherwise varied in details, well serves the purpose of an assay. The powdered root is percolated to exhaustion with alcohol (not acidulated) This is done much the best by the continuous operation of an extraction apparatus. The solution is concentrated, preferably by boiling under reduced pressure, to remove the alcohol, the liquid diluted with water to a limpid state, and just acidulated with tartaric acid. One part of tartaric acid to 100 parts of the root is the propor- tion of Duquesnel's process, in which the acid is added to begin slide, is treated with a drop of water acidulated with acetic acid, and a minute .fragment of potassium iodide added, when presently rhombic tables appear under microscopic inspection. Obtained with 0.0000 5 gram. 1 When aconite is dissolved in hot phosphoric acid previously fully concen- trated on the water-bath, there appears, according to the purity of the' alkaloid, a violet to brown color at all events crystallized aconitine is but feebly colored by the phosphoric acid, and crystallized aconitine nitrate is not colored at all. The yellow color by sulphuric acid diminishes in the same way (FLUCKIGER'S "Pharm. Chem.," 1879). Concentrated aqueous phosphoric acid dissolves aconi- tine, giving on the water-bath a beautiful violet color, remaining for a day in the cold a distinction from "pseudaconitine" (that is, "napelline." "Morson's aoonitine," or "English aconitine"), which remains colorless (HEPPE'S "Die ohemischen lleaotionen." 1875, from HUBSCHMAXV, HASSFLT. HBRBST. PRAAG). "I found the color yellow at 80 0., reddish at 80 0., violet at 133 C.'' DRA- GENDORFF in "Orgnnische Gifte," 1872. JUERGENS (1885) obtained purified aconitine which gave no color reactions with phosphoric acid, sulphuric acid and sugar, or phosphomolybdic acid and ammonia. 28 ACONITE ALKALOIDS. with. The liquid is now filtered, by help of the filter-pump, and the resinous residue washed with a little water. The solu- tion is now washed several times with ether, the total etherial washings being washed with a little water slightly acidulated with tartaric acid, returning the aqueous washing to the acidu- lous solution. Sodium carbonate is now added to a clearly alka- line reaction, and the liquid shaken out with ether to complete exhaustion. The etherial solution is concentrated in a flask as far as it may be without formation of residue, and then washed several times w r ith water slightly acidulated with tartaric acid ; seeing that the reaction is distinctly acid after shaking with the ether. The aqueous liquid is at once made barely alkaline by adding sodium carbonate (if deemed advisory, is washed once with light petroleum benzin), and then shaken out with ether, re- peatedly, as before. The united etherial solution is concentrated, at last spontaneously, to crystallize ; or when partly concentrated a little light petroleum benzin is added and the solution set at rest to concentrate and crystallize. In either case all resinous residues are thoroughly washed with ether by the filter-pump, and this etherial solution shaken out again with acidulated water, made alkaline, and shaken out with ether, concentrating this solution to crystallize as before. The crude crystallized and amorphous alkaloids may be purified by repeatedly dissolving them with ether, on the filter, by the filter pump, and " crystal- lizing " again, to obtain the total free alkaloids for weight. Or the crude crystallized and amorphous alkaloids are treated with a strong solution of sodium nitrate at a gentle heat, and cooled for crystallization of the nitrates of the alkaloids. These may be further purified by treating their concentrated aqueous solution, made alkaline by sodium carbonate, with repeated portions of chloroform, to obtain all the alkaloid, and permitting the chloro formic solution to concentrate for crystallization of crystallizable alkaloids. It is much better if a " liquid-extraction apparatus " be used throughout the process, instead of " shaking out " by many portions^ of the solvents. And it is much better to make the concentrations promptly, by partial vacuum, at temperature not above 60 C. In separation from animal tissues, etc.. in cases of possible poisoning, the same method, substantially, may be followed ex- tracting the neutral or neutralized mixture with alcohol, concen- trating, then acidulating and filtering, as above directed. A mix- ture of chloroform and ether is preferred by some analysts, and chloroform alone by others, as a solvent for the extractions. If crystals are not readily obtained, the final purified portions may ACONITE ALKALOIDS. 29 be obtained in concentrated neutral aqueous solutions for de- terminative tests. The physiological test should be lirst, and then drop tests are to be made upon a glass slide over white or black ground, under a magnifier. If the alkaloids of aconite be identified, a further effort should be made to obtain the crystals. The aconite alkaloids have been recovered from the liver and other organs, from the blood, and from the urine. Aconitine was detected by DRAGENDORFF in the stomach two months and nine days after death. 1 y. Quantitative. Aconite alkaloids may be dried at 100 C. for gravimetric determination. The gold salt of aconitine pure is best dried over sulphuric acid in the dark, when a constant weight at 100 C. may be rapidly assured, and the product weighed as CggH^NO^.HCl.AuClg (WEIGHT). The gold pre- cipitate of the probably mixed aconite alkaloids was found by DRAGENDORFF to have from 25 to 31 per cent, of gold, as sepa- rated by warming with sulphuric and oxalic acids. 2 Volumetric estimation of (total) alkaloids of the aconites are made by Mayer's solution with approximate results as follows (DRAGENDORFF) : The solution is made (by a previous approxi- mate assay) to contain one part alkaloids to 150 or 200 parts of water, and slightly acidulated. The end of the reaction is found by filtering a drop or two, through a very small filter, upon a watch- glass, and adding a drop from the burette, when, if turbidity ap- pears, the watch-glass and filter are drained and rinsed with a few drops of water into the alkaloidal solution, and another ad- dition made from the burette. Each c.c. of the Mayer's solution indicates 0.0274 gram of the alkaloid (empirical), the amount to be increased by 0.00005 gram for each c.c. of the total liquid containing the precipitate. The results are near enough indica- tions of the quantity of total alkaloids to be practically useful for commercial assays of aconites and their preparations pro- vided always that quantity of total alkaloids could serve a com- mercial purpose in absence of any index of the proportion of amorphous alkaloids. A method of estimation of the crystollizdble and physiologi- cally active alkaloids was proposed by Mr. WRIGHT in 1877, 8 to be done by saponification, and estimation of the resulting benzoic 1 For the instructive account of analysis by Drs. DUPRE and STEVENSON, in the Lampson case, in London, in 1882. see The Lancd, March 18, 1882, p. 455 ; Wharton and Still? s " Med. Juris.," vol. 2, 1884, Phila. ed., p. 634. 2 "Gerichtl Chemie," 1872, p. 62. z P/tar. Jour. Trans., [3] 8, 164-178. 30 A CO NI TIC ACID. acid, and dimethylprotocatechuic acid (see p. 18). Saponitica- tion is made complete by boiling alcoholic potash, or by water with digestion at 140-150 C., in sealed tubes. Distilling with water separates the benzoic acid from the dimethylprotocatechuic acid. The weight of the benzoic acid is ^ that of the aconitine. The weight of the dimethylprotocatechuic acid is that of the pseudaconitine. g. Commercial grades and values. An elaborate pharma- cological valuation of several brands of aconitine was made, using frogs, rabbits, dogs, and pigeons, by PLUGGE in 1882. ' It was determined that Jretiffl "nitrate of aconitine" was eight times stronger than Merck's " nitrate of aconitine," and one hun- dred and seventy times stronger than Friedlander's ; also, that " German aconitine " is variable. Of the samples examined by Plugge he found the following order of diminishing strength : " Nitrate of aconitine " : (1) Petit's, (2) Morson's, (3) Hottet's, (4) Hopkins and Williams's " pseudaconitine," (5) Merck's " aco- nitine nitrate," (6) Schuchardt's " aconitine sulphate," (7) Fried- lander's " nitrate of aconitine." These figures must not be taken as indicating the strength of all the alkaloids furnished under these respective brands. Dr. SQUIBB (p. 23) found the relative strength of four articles to be, in proportion : Duquesnel's "crystallized aconitine," 111; Merck's "aconitine from Hima- laya root " (pseudaconitine), 83 ; Merck's " aconitine " (ordi- nary), 8 ; unknown " aconitine," 1 ; the powdered root of A. Napellus, 1. The "Aconitine japonicum" of Merck claims to be japaconitine. ACONITIC ACID. H 3 C 6 H 3 O 6 = 174. Found in Aconi- tum Napellus (monks-hood) and other species of Aconitum, in Delphinium Consolida (larkspur), in JEquisetum, Helleborus niger, Achillea Millefolium (yarrow), Adonis vernalis, and other plants. It is a product of citric acid by heat, and occurs in various citric acid concentrated juices of commerce, in sugar- cane juice, 8 and in the scale from sorghum-sugar pans, 3 but it is not manufactured for use Crystallizes in white, warty masses, or very slowly in four-sided plates or hard needles. It darkens at 130 C., melts at 140 C., and boils at 160 C., when it gradu- 1 Arcltiv d. Phar., [3] 20; Am. Jour. Phar., 54, 171. Also, on this ques- tion, HARNACK and MENNICKE, 1883. 2 BEHR, 1877 : Dfut. Chem. Ges. Ber., 10, 351. 3 II. B. PARSONS, 1882 : Am. Chem. Jour., 4, 30 : Jour. Chem. Soc., 42, 766. A CONITINE.^ESCULIN. 3 1 ally decomposes into Itaconic acid, C 5 H 6 O 4 , and carbon dioxide. Citraconic anhydride and other pyrocitric acids occur at higher temperature. Aconitic acid is soluble in water, alcohol, and ether ; its solutions have a strongly acid reaction, and a purely acid taste. It is tribasic and forms three classes of salts. Free aconitic acid solution is precipitated by solutions of mercurous nitrate and lead acetate, and alkali aconitates are precipitated by lead nitrate, silver nitrate, and ferric chloride (red-brown). Calcium aconitate is only sparingly soluble in water. Phos- phorus pentachloride, with heat, gives a cherry-red liquid, de- colored by water. Nitric acid in boiling solution is deoxidized with evolution of brown vapors. Aconitic acid is prepared from plants in which it exists as calcium salt, by evaporating the clear decoction to crystallize. The crystals of aconitate of calcium are dissolved by slight acidu- lation witli nitric acid, and precipitated by acetate of lead, and the lead salt decomposed by hydrosulphuric acid. The residue of the tiltrate is taken up by ether, and the acid remaining on evaporation of the ether is dissolved in water and crystallized in vacuum over sulphuric acid. 1 It is also separated from im- purities by adding (to the dry mixture) five parts of absolute alcohol, then saturating the filtered solution with hydrochloric acid, and adding water, when aconitate of ethyl will rise as an oily layer, colorless and of aromatic odor. This ether may be transposed by potassium hydrate. Aconitic acid may be best obtained, artificially, from citric acid. 2 ACONITINE. See ACONITE ALKALOIDS. -dESCULIN. C 15 H 1? O 9 =240 (SCHIFF, 1870; LIEBERMANN, 1880). The bitter principle of the bark of the horse-chestnut (^Esculus hippocastanum). Not identical with gelsemic acid (WosMLEY, 1882). Obtained by precipitating a decoction of the bark with lead acetate, filtering, and, after removing the lead from the filtrate by hydric sulphide, concentrating to a syrup and allowing to crystallize. It may be purified by repeated crystallization from alcohol and finally from boiling water. Crystallizes in snow-white, very small needles, arranged in 1 BUCHNER : Pharm. Repert.,,6^ 145. A method of separation from Fquisetum was given by BAUP in 1850 : Liebig's Annalen, 77, 293 ; Jahr. d. Chem., 1850, 372. 2 PAWOLLECK, 1876 : with process, Liebig's Annalen, 178, 150 ; Jour. C/tem. Soc., 29, 375. 32 ALKALOIDS. globular masses or in the form of fine powder. They have the composition C 15 II 16 O 9 2H 2 O, and lose l^H^O at 110 C., and the rest of the water upon melting at 160. It is odorless, slightly bitter, and reddens litmus. Soluble in 642 parts cold and 12 parts boiling water, in about 100 parts cold and 2-i parts boiling alcohol; insoluble in absolute, slightly soluble in ordinary ether ; soluble in dilute acids and alkalies. The aqueous solution (con- taining the merest trace of the glucoside) exhibits a distinct blue fluorescence, which is more marked if well-water is used, and is destroyed by addition of acids. The alkaline solutions are yel- low, but exhibit a blue fluorescence. It is dissolved by chlorine water with red color which changes through brown-red to yellow. Nitric acid forms a yellow solution with it, which becomes red upon addition of excess of potassium hydrate. Boiling with dilute acids converts it into cesculetin, C 9 H 6 O 4 , 1 and glucose. Ferric chloride colors its solutions green. It reduces alkaline cupric solution upon boiling. It is not precipitated by any of the metallic salts except lead subacetate. If a small portion of aesculin be treated with four drops of concentrated sulphuric acid, and to the slightly colored solution there be gradually added a solution of sodium hypochlorite, a bright violet colora- tion is obtained (RABY, 1885). ALKALOIDS. Nitrogenous carbon- compounds capable of neutralizing acids. CONTENTS : Basal character ; solubilities in water, in the immiscible sol- vents, free and acidified ; extraction by solvents ; management of emulsions ; filtering out ; styles of "separators" ; stoppers; siphon for separators; tests of completed extraction ; the purity of the immiscible solvents ; liquid-extrac- tion apparatuses ; forces affecting solubilities. Precipitation by alkalies ; the scheme of Fresenius ; the "general reagents "for the alkaloids, with the re- covery of the alkaloid from each (1) iodine, (2) Mayer's solution, volumet- ric uses, (3) phosphomolybdate, (4) bromine, (5) cadmium iodide, (6) bismuth, (7) tungsten compounds* etc., (8) tannin, (9) picric acid, (10) platinic and auric chlorides ; color-reactions, with sulphuric acid alone and the several oxidizing agents, cane-sugar, etc. ; Froehde's reagent ; nitric acid ; ferric chloride, etc. Microscopic methods ; microsublimation, and "the subliming cell." In their most obvious characteristics these compounds are mostly divisible into two classes: (1) Non- volatile Alkaloids, com pounds of C, H, N, O ; solids, melting and subliming usually with partial decomposition when heated. (2) Volatile Alkaloids, compounds of C, H, 1ST ; liquids of slight vaporization at ordi- nary temperatures and high boiling points. The natural alka- 1 On the constitution of aesculin and sescnletin, LIEBERMANN, 1880 ; WILL, 1883. ALKALOIDS. 33 loids of the first class are far more numerous than those of the second class. Both classes mostly include bodies of decided basic power ; of an alkaline reaction restricted by sparing aqueous solubility ; bases neutralizing acids in the production of their salts, which crystallize in characteristic forms of a good degree of perma- nence. In water the free alkaloids have generally little solubility, but their sulphates, nitrates, hydrochlorides, and acetates mostly dissolve with abundance in this vehicle. In alcohol the free alkaloids dissolve in most cases with moderate abundance, and their common salts almost invariably dissolve largely. In the solvents immiscible with water ether, chloroform, benzene, petroleum benzin, amyl alcohol, etc. the free alkaloids differ among each other as to their solubilities, which thus be- come important means of separation. The salts of the alka- loids are, with some important exceptions, insoluble in the sol- vents immiscible with water. Separations of alkaloids soluble in a liquid not miscible with water, from other substances soluble in the same menstruum, are, therefore, accomplished by first washing the acidulated aqueous solution to remove whatever non-alkaloidal matter is soluble in the applied menstruum, and then washing the alkaline aqueous liquid to take out the alkaloid itself. 1 Then, again, the non- aqueous (etherial) solution of the free alkaloid may be washed with acidulated water, when a salt of the alkaloid is formed and transferred to the aqueous liquid, as a step in separation. The washing of the aqueous liquid with a solvent immiscible with water, sometimes designated as the shaking out, is com- monly done by agitating in a cylindrical stoppered vessel (Fig. 1, p. 35), and leaving the mixture at rest for the immiscible sol- 1 This mode of using ether was proposed in 1856 by OTTO, in modification of STAS'S process for the recovery of alkaloidal poisons. The plan was adopted for chloroform by RODGERS and GIRD WOOD in 1856 ; and for amyl alcohol by USLAR and ERDMAXN in 1861. In 1867 DRAGENDORFF (rhar. Zeitsch. f. JKuss- land, 6, Heft 10; Zeitsch. anal. Chem., 7, 521 ; "Ermittelung von Giften," St. Petersburg, 1868, p. 242) presented a quite comprehensive scheme of separa- tions by solvents immiscible with water, applied both in acidulated and in al- kaline solutions. This scheme was translated by the author, in "Outlines of Proximate Organic Analysis " in 1875, and, more in detail, by S. Dana Hayes (Am. Chemist, 6, 378) in 1876. The plan of separation, first published in a pharmaceutical journal, and primarily for the uses of the toxicologist, has been extended by chemists everywhere, so that it is now the most common mode of separation of alkaloids for any purpose, in analysis or manufacture. Moreover, the way of "shaking out" by solvents immiscible with water is in frequent use for fats and acids and other bodies besides alkaloids. 34 ALKALOIDS. vent to separate in a clear layer, which is then drawn off or de- canted in some way. The solvent layer will be over the aqueous layer in the case of the ordinary solvents except chloroform, the layer of which will be under the watery liquid. A mixture of one volume of chloroform witli three, or at the least two, volumes of ether is sometimes used as an immiscible solvent, lighter than water. Mixtures of alcohol (as a solvent) with ether, or chloro- form, or amyl alcohol cannot be used in " shaking out," because the water removes the alcohol from the immiscible liquid. In fact, this liquid becomes water- washed by the operation, and there are advantages in taking a water- washed ether or chloroform to begin with, so that the disturbing presence of alcohol (and pos- sibly of acids) may be avoided. It is to be borne in mind that ordinary stronger ether contains 4 or 5 per cent, of alcohol, and ordinary purified chloroform contains alcohol not exceeding 1 per cent. ; also that both these liquids are liable to contain, and to acquire, free acids. It is even possible that, in shaking out with several portions of acidulous ether, the reaction of the aque- ous liquid may be changed from alkaline to acid, and if this change be overlooked the separation may be reversed without the knowledge of the operator. The absence of free acid, therefore, is to be required of ether, chloroform, or amyl alcohol when one of these is used as a solvent upon an aqueous liquid. Washing with water, readily done by the analyst, serves to remove both alcohol and acids, 1 but the removal of acids is done sooner and with less waste by washing with alkaline water. "What is said of " water- washed " solvents by no means applies to the commercial article known as " water-washed ether," which is of low grade, containing much alcohol, a slight extent of water- washing being substituted for other more efficient means in its purification. Although the presence of alcohol somewhat lessens the sepa- rative power of the solvent, yet the addition of small quantities of alcohol is sometimes resorted to to promote the formation of a clear layer of the immiscible solvent, and (as a diluent) to resolve obstinate emulsions which now and then hinder the analyst. The various resources for preventing and destroying emulsions are named from time to time in the directions in this work. The resolution of an emulsion into the two clear layers of the immiscible liquids concerned is always promoted by some degree of miscibility between these liquids, just as a precipitate that has some slight degree of solubility, or that crystallizes, 'usually sub- 1 The use of water-washed solvents, as standard grades of constant compo- sition, was proposed by the author in 1875 (Pro. Am. Asso. Adv. Sci., 24, i., 114). ALKALOIDS. 35 sides the more readily to leave a clear liquid. Ether forms a layer sooner than chloroform, and benzene is liable to give more trouble in the formation of emulsions than either of the former. The operator will learn that in most cases it is better to avoid the production of an obstinate emulsion, not shaking violently enough to cause it, but, if necessary, obtaining the desired contact of the two liquids by a slow and prolonged reversing of the upper and lower ends of the separator. Precautions against emulsions, and devices for their resolution, are given with the various direc- tions for separations of Atropine, Cocaine, Strychnine, and else- where in this work. Among such measures may be here enume- rated : (1) the application of heat enough to cause a very slight or incipient boiling of the solvent, or of the water when amyl alcohol is the solvent ; (2) the introduction of small portions of the clear solvent, with or without clear water, through a little tube, into the intermediary layer of emulsion ; (3) the addition of a small portion of the fresh solvent, then gently agitated and set aside for separation of layers, this being done either with the whole liquid or with the emulsified portion of the liquid drawn off for the purpose ; () the dilution of the solvent with alcohol ; (5) gently jarring the separator ; (6) filtrations. The emulsified intermediary layer, drawn oif by a siphon or pipette, or, if need be, the entire mixture, may be filtered, using a double paper filter (with four thicknesses all around), and wetting the filter with the heavier of the two constituent liquids. That is, with fresh chloroform, if this be solvent ; with distilled water, if the solvent be other than chloroform. The first portion of the filtrate, or even the whole of it, may be returned through the filter, and the filter and lighter liquid remaining in it may be washed with successive small portions (or with a fine, continuous stream) of the heavier liquid. As a "separator" the author prefers one with a cylindrical body and a short, conical base, the exit- tube being of small diameter and closed with a stop- cock next to the body. The stoppered opening at the top of the separator should be of good width. Fig. 1 represents a convenient article, to be held by a " condenser clamp." But instead of a " separator," a large test-tube, or test-glass with foot, may be used with convenience, if provided as follows : The top of this cylindrical tube is fitted just like that of a wash- bottle, with a stopper bearing a delivery-tube and blow-tube, as 36 ALKALOIDS. illustrated in Fig. 2. The delivery-tube is to be narrow, and play up and down in the stopper, to take off the liquid content, either the upper or lower layer, at any point. The blow-tube is so bent and long enough to enable the operator while blowing to see clearly the movement of the liquid at the inner end of the delivery-tube, when this is brought near the line. The division between layers may be carried to very near the outer end of the delivery-tube, when the remaining liquid is drawn back again. To rinse the deli very- tube the stopper is transferred to a tube containing a little of the clean solvent, which is shaken up and then blown out. To make an exact separation of the layers, a small quantity of the fresh chloroform or other solvent may be drawn in through the delivery-tube of the apparatus last above mentioned, next to the aqueous layer, without disturbing the layers, which are thus separated from each other. In other apparatus the introduction may be through a pipette. Rubber stoppers and tubes are acted on by ether and chloro- form, and can only be used when the liquid does not come in contact with them, and then only for a short time, as they 'are soon injured and swollen by the vapor of these menstrua. Good, ALKALOIDS. 37 well-pressed corks serve for brief uses without special prepara- tion ; but to avoid waste of vapor in standing, and especially where the solvent is to be distilled, as described hereafter, the corks should be rendered impervious, after being fitted, by an application of chrome-gelatine. Four parts of gelatine are dis- solved in 52 parts of boiling water, the solution filtered, and 1 part of ammonium dichromate added. This mixture is applied as a coating to the corks, and permanent cork connections may be completely sealed by covering the corks in place over upon the glass. After application the coating should stand two days in the light to harden. It will occur to any analyst sometimes to make separations with immiscible solvents, as preliminary trials, or as small quali- tative or quantitative tests of a tentative character, when a test- tube or' vial is a sufficient container, and the one liquid may be drawn off from the other with a pipette. In using a mouth pipette, 'however, it is usually better to take out the aqueous layer, this being the less volatile liquid, and less liable to drip when the pipette, closed at the top, is being withdrawn. Also a simple siphon of narrow glass tubing bent in U-form may be filled with the solvent or with water, and used to draw off either layer from any container. In any case, a separation by or from an immiscible solvent is of the nature of a washing, and complete removal of the dissolved body is not accomplished by a single division into the two liquid layers, or with a single portion of the solvent. Suc- cessive portions of the solvent must be applied, in repetition of the " shaking out." Especially is this true with ether, chloro- form, and amyl alcohol, which dissolve in water to some extent. From two to five washings may be required. In any case of doubt and of importance, positive information must be gained by a test of the last " wash-liquid," as in ordinary quantitative analy- sis, and the washings repeated until the last liquid drawn off, or the residue therefrom, gives a negative result under some deli- cate test for the alkaloid operated upon. In all the cases where assay operations, by a single shaking out with (say) chloroform, have been verified by good authority as giving a correct result under a control analysis, it may be almost certainly set down that the correctness of the result lies in a happy balance of errors rather than in the clear truth. The loss of the alkaloid taken is just balanced by the gain of foreign matter which goes into the weight at the end. And if all tlie conditions of loss and of gain can be held constant, o* nearly so, the method may give results of substantial correctness. ALKALOIDS. The purity of the immiscible solvents chosen for use must be assured. Let a good portion be evaporated to dryness in a weighed beaker, and the absence of fixed residue ascertained. The residue -may well be taken up with acidulated water, and the solution subjected to test by some of the " general reagents for alkaloids," or by the chief qualitative test to be used in the contemplated analysis, purified by distillation. If necessary, the solvents are to be To avoid the attenuation due to the use of repeated portions of solvent, as well as the expense of considerable quantities of the same, a plan of distillatory use of the solvent has been recently proposed, in the so-called " extraction- apparatus for liquids." This apparatus corresponds in principle to the ex- traction-apparatus of Tollens and others for the continuous per- ALKALOIDS. 39 eolation of solids, which have been for some years the favorite means of applying solvents to organic bodies, and is described under Plant Analysis. The immiscible solvent is distilled from its solution while it is being applied, in the apparatus of later device, to the aqueous liquid. The apparatus of SCHWARZ (1884) 1 is shown in Fig. 3. It is connected above with a returning con- denser. The two connecting tubes serve, the one to carry vapor to the condenser, the other to conduct the overflow of condensed solvent back to the warmed reservoir both these tubes having a mercury-joint provided for by an inclosing cup. NEUMANN'S apparatus 3 will be understood from Fig. 4. A. EILOART (1886) 3 describes a simple apparatus (Fig. 5) which can be set up by any chemist with glassware at hand, including a small condenser, the small glass tubing to be bent and fitted in stoppers, as shown in the figure. The tube delivering the solvent into the aqueous liquid may be made with a funnel- end, as figured, so that perforated platinum foil may be bound over the expanded orifice, and the solvent distributed in fine streams. This apparatus, in Fig. 5, applies the hot vaporous solvent to the liquid to be ex- tracted, which is therefore maintained at near the temperature of boiling of the sol- vent. The same is true of the apparatus of Neumann and of Schwarz (Figs. 4, 3). For fats this heat of the aqueous mixture is needful, and for many substances, includ- ing some alkaloids, it may be desirable, but with some alkaloids ;t is not admissible. And Eiloart presents a modification of his apparatus in Fig. 6, whereby the solvent reaches the aqueous liquid from the con- denser, an.d not directly from the distilling flask ; so that, if the condenser be kept cold enough, there will be no heating of the aqueous liquid, the temperature of which may be regulated at will. All the forms of liquid-extraction apparatus so far described in publications are devised for light volatile solvents, constitut- ing the layer above the watery liquid. For chloroform, received in the layer below the aqueous one, the apparatus illustrated in 1 Zeilsch. anal. Cliem., 23, 368. 2 1885 : Ber. d. chem. Ges., 18, 3061. 3 Chem. News, 53, 281. ALKALOIDS. Fig. 7 may be used, with attention now and tlien, to transfer the chloroformic layer to the distilling flask. In doing this the valve leading to the con- denser is closed, the lower valve is opened, and pressure then applied at the outer opening of the blow-tube until the chloroformic layer is siphoned over. The degree of solubility in the immiscible sol- vents varies with forces of adhesion and cohesion not operative in dissolving from the dry mass. The solubility of an alkaloid, in agitating its acidulous watery solution with ether or benzene at the mo- ment the liquid is made alkaline, may be more or less abundant than the solubility of the dry alka- loid in ether or benzene. 1 The moment of liberation of the alkaloid from its salt is certainly the most favorable time for its free solubility. Therefore many operators, in dissolving by agitation, add first the immiscible solvent and agitate, and then add the alkali for liberation of the alkaloid, when the agi- tation is con- tinued. And it is to be borne in mind that the fac- tors of solubil- ity, reported for a certain sol vent with great minute- ness precisely FIG//. as obtained by experiment at a given tem- perature, are liable to vary within liberal limits by influence of several condi- tions besides temperature. 1 "Comparative Determinations of the Solubilities of Alkaloids in Crystal- line. Amorphous, and Nascent Conditions : Water-washed solvents being used." The author, 1875 : Pro. Am. Asso. Adv. Sci., 24, i. Ill ; Am. Chem., 6, 84; Jour. Chem. Soc., 29, 403. ALKALOIDS. 41 A common plan for separation of alkaloids by reason of their diverse solubilities, brought into use at a very early period, re- quires no other menstruum than water, and consists in dissolving out the alkaloid as a salt, by use of acidulated water, and preci- pitating the alkaloid, free, by adding an alkali to the clear aque- ous solution. In operations of this sort alkaloids have relations like those of metallic bases other than the alkalies. Like the metallic bases, alkaloids are in some instances dissolved by free fixed alkalies, or an excess of this alkali precipitant, in other in- stances dissolved by an excess of ammonia, and in many cases not dissolved by excess of any alkali. An acidulous watery so- lution of cinchona bark, in the clear but colored filtrate, on add- ing solution of sodium hydroxide to excess, presents an abun- dant precipitate of the mixed impure cinchona alkaloids, colored "by extracted matters. Precipitation by one of the alkalies or alkali earths has a place in various processes for preparation of alkaloids from vegetable sources, and a share among the means of qualitative and quantitative analysis. Thus in most of the methods of the morphiometric assay of opium, ammonia is added to the aqueous solution of morphine salt, when simple trans- position occurs, as follows : (C 17 H 19 NO 3 ) H SO 4 +2]SrH 4 OH= 2C 17 H 19 ISrO 3 H 2 O(cryst. morphinej+tNII^SC^. In one of the preferred methods the morphine is dissolved out of the opium by an excess of lime, the resulting lime-solution being treated with ammonium chloride, when a transposition occurs, precisely corresponding to that of a precipitate of aluminium hy- droxide according to the equation : K Q A1 O 4 +2NH 4 C1+4:H O = A1 3 (OH) 6 +2KC1+2XH 4 OH. And" no" more absolute separa- tion of the chief alkaloid of opium than this crystalline preci- pitation (favored by the contact of immiscible solvents) has yet been established. The action of certain of the alkalies, used in excess, to re- dissolve the precipitates they form in solutions of alkaloid salts, has been made available in analytical separations. Fresenius's manual of qualitative analysis has long presented a scheme of separation, or of classification, of a few common alkaloids, as follows : Of Non-volatile Alkaloids, (1) those which are precipitated by potassa or soda from the solutions of their salts, and redissolve readily in an excess of the precipitant (morphine) ; (2) those which are precipitated by potassa or soda from the solutions of their salts, but do not redissolve to a per- ceptible extent in an excess of the precipitant, and are precipi- tated by sodium bicarbonate even from acid solutions (narcotine, quinine, cinchonine) ; (3) those which are precipitated by potassa 42 ALKALOIDS. from the solutions of their salts, and do not redissolve to a per- ceptible extent in an excess of the precipitant, but are not pre- cipitated from (even somewhat concentrated) acid solutions by the bicarbonates of the fixed alkali metals (strychnine, brucine, veratrine, atropine). The solubility of quinine, and the far more difficult solution of the other cinchona alkaloids, in an excess of ammonia, is used in the valuable method of Kerner for separa- tion of quinine from other cinchona alkaloids, and estimating the proportions or fixing the limits of the latter. Finally, it remains to notice that, although the salts of the common mineral acids (sulphuric, hydrochloric, nitric) with the alkaloids, are soluble in water, there are certain double salts whereby nearly all alkaloids are precipitated, in somew T hat com- plex compounds nearly insoluble in water. The precipitants are known as The General Reagents for Alkaloids. The most use- ful of these are (1) Iodine in solution of potassium Iodide, (2) Potassium Mercuric Iodide, (3) Phosphomolybdate, (4) Bromine in aqueous hydrobromic acid, (5) Potassium Cadmium Iodide, (6) Potassium Bismuth Iodide, (7) Tungsten compounds, phos- phoantimonic acid, and ferric chloride with hydrochloric acid, (8) Tannic Acid, (9) Picric Acid. In applying a precipitant to a solution of an alkaloid, when it is desired to avoid expenditure of the material under examina- tion, a drop of the solution is to be treated with a drop of the reagent, on a glass slide placed over black paper. A hand- magnifier is serviceable. (1) Iodine in Potassium Iodide Solution (WAGNER, I860). 1 A decinormal solution of the free iodine : 12.66 grams of iodine in a liter of solution of iodide of potassium ; or, 20 grams iodine and 50 grams potassium iodide per liter (WORMLEY). Applied, as it is, in acidified solution, it is in effect iodized hydriodic acid. Brown and flocculent precipitates ; generally with very little solubility in water ; formed more perfectly in acidulous solutions, and in those containing a little free sul- phuric acid. Iodine tincture is a less useful form of the re- agent. The precipitates are more or less soluble in alcohol. A very slight addition of the reagent is sufficient, and it is better not to use enough to give color to the solution. In a liquid liable to contain dissolved substances not alkaloids, the fact of precipitation is not strongly characteristic, while the absence of precipitation is conclusive for ordinary alkaloids. 1 Zeitsch. anal. Chem., 4, 387. GENERAL REAGENTS. 43 On standing, the precipitates in most instances crystallize in somewhat characteristic forms, more perfectly from solutions in alcohol. In composition (HILGEK, 1869 ; BAUER, 1874) the precipitates are addition compounds, of different but related types. When quinine sulphate solution is treated with a little of the reagent, there is formation of C 20 H 24 NoOo.HI.I ; with more of the re- agent, quinine pentiodide, C 20 lf 2 ^ 2 O 2 . HI . I 4 , is formed ; and in presence of excess of alcoholic iodine and sulphuric acid, various iodosulphates are formed, as stated more fully un- der Quinine, d, " Herapathite test." Atropine pentiodide, 17 Ho 3 NO 3 . HI 5 , obtained by excess of the reagent, crystallizes from liot alcoholic solution, in fine blue-green, lustrous needles or plates. A corresponding tri-iodide is obtained by adding less of the iodine. Strychnine tri-iodide crystallizes from alcoholic solution in long, dark-brown prisms, of rhombic shapes, with bluish-metallic lustre. Thrown down as an amorphous preci- pitate it is red-brown. Berberine tri-iodide, Co H 17 NO 4 . HI 3 , crystallizes from hot alcohol in long, red-brown, diamond-lus- trous needles. Piperine tri-iodide, (C 17 II 19 NO 3 ) 2 HI 3 (JOKGEN- SEN, 1877), crystallizes from hot alcoholic solution in long, steel- blue needles of metallic lustre. Recovery of the free alkaloid from the precipitates of hy- periodides may be accomplished as follows : The washed preci- pitate is dissolved in excess of aqueous sulphurous acid, and the solution evaporated on the water-bath, the sulphurous acid being kept in excess until the hydriodic acid is expelled, when the former is also driven off and the alkaloid remains as a sulphate. The hyperiodide precipitates dissolve in solution of thiosulphate, and may be thereby separated from various foreign matters carried down by adding free iodine to organic extracts. If the thiosulphate solution be treated with the iodine solution in ex- cess, the alkaloid is again precipitated. (2) Potassium Mercuric Iodide. Mayer's Solution. 1 The 'F. L. WINCKLER, 1830. A. v. PLANTA-REICHENAU, " Das Verhalten der wichtigsten Alkaloidegegen Reagentien " (S. 41), Heidelberg, 1846. THOMAS B. GROVES, "On some compounds of iodide and bromide of mercury with the alkaloids," 1859: Jour. Cham. Soc.. n, 97, 188 ; Phar. Jour. Trans., 18, 181 ; Am. Jour. PUnr.. 36. 535. FERDINAND F. MAYER, 1862-3: Pro. Am. Pharm., 1862, 238; and Chem. News, 7, 159; 8, 177, 189 ; Am. Jour. Phar., 35, 20 ; Zi'itsch. anal. Chem., 2, 225; Jafir. Chem., 1863, 703. G. DRAGEKDORFF. ' Werthbestimmung," 1874, p. 9 and elsewhere. A. B. PRESCOTT, "Estima- tion of alkaloids by potassium mercuric iodide,'' J880: Am. Chem. Jour., 2, 204: Jour. Chem. Soc., 42, 664: Chem. Newx t 45, 114; Ber. d. Chem. Oes., 14, 1421. 44 ALKALOIDS. solution proposed by Mayer is the one generally used for pur- poses qualitative or quantitative. It is a decinormal solution of (HgCl 2 +6KI) = the hydrogen equivalent of Hg. Of dry, crystallized mercuric chloride, 13.525 grams ; potassium iodide, 49.680 grams ; separately dissolved in water, and the mixed solu- tions made up to one liter. The reactions of the solution appear to correspond with the formula KIHgI 2 .(KI) 3 -|-2KCl, 1 instead of (KI) 2 HgI 2 +2KI+2KCl. Dragendortf prefers to make quan- tities, above specified, to 2 liters instead of 1. Mayer's solution is applied only in acidulous solutions, in testing for alkaloids ; therefore ammonia does not interfere, as the precipitate of mercurammonium iodide is not formed in pre- sence of free acids. The acidulation may be with sulphuric or hydrochloric acid, and may be strong without dissolving the precipitate. The solution tested must not be alcoholic, and must not contain acetic acid. Some organic matters other than alkaloids cause precipitates. With strychnine the precipitate is obtained in dilution of 1 to 150000 ; with quinine, in solutions of about the same dilution ; while with morphine, or with atro : pine, solutions of 1 to 4000 do not give the precipitate. The precipitates are curdy or flocculent, and for the most part of a yellowish-white color. Caffeine and theobromine are not precipitated by potassium mercuric iodide. The composition of some of the alkaloid iodomercurates varies with conditions of concentration, excess of reagent, and acidity ; while the precipitates of other alkaloids are nearly con- stant in composition. With strychnine the precipitate is not far from C 21 H 22 N 2 O 2 HIHgI 2 2 ; with morphine the precipitate cor- responds to a variable mixture of (C 17 Hi 9 NO 3 ) 4 (HI) 4 (IIgI 2 ) 3 and (C 17 H 19 NO 3 ) 4 (HI) 6 (HgI 2 ) 3 ; with quinine the precipitation ap- pears to be most nearly, though not closely, represented by (C 20 H 24 K 2 O 2 ) 2 (HI) 3 (Hgl 2 ) 3 ; and with atropine the gravimetric value of the" precipitate does not correspond to its volumetric factor. In volumetric use the " end-reaction " is denoted only by the J In the proportions for (KI) 2 HgI 2 + 2KCl, the mercuric iodide remains dis- solved only in concentrated or hot solution. The quantity of alkali iodide adopted by Mayer cannot be very much reduced and retain solubility at the decinormal dilution in the cold. A permanent solution with the help of bro- mide can be obtained as follows: HgCl 2 + 4KI + KBr : mercuric chloride, 13.525 ; potassium iodide, 33.12 ; potassium bromide. 5.94; water to 1000 by volume. This solution may be supposed to contain (KI) 2 HgI a + KBr + 2KCl. (The author, 1880: Am. Chem. Jour.. 2, 304.) 2 The author, 1880 : Am. Chem. Jour., 2, 206. GENERAL REAGENTS. 45 completed precipitation. 1 After the last addition from the bu- rette the precipitate is either allowed to subside, or a little por- tion is filtered out and a drop of the reagent added from the bu- rette to the clear solution. Some of tlie precipitates subside readily, strong acidulation usually favoring this result ; with others much time is required, and titration in this way is gene- rally slow. Filtration is the better way : using a minute niter, not over 5 millimeters or J inch in radius, held in a loop of pla- tinum wire or a coil of drawn-out glass tubing, over a glass slide placed upon black paper. A drop or two is taken, with the stir- ring-rod, from the mixture containing the precipitate, filtered through the wet filter, and treated over the black ground with a drop of the reagent from the burette, when the slightest turbid- ity can be seen. Before the end of the titration all the test-por- tions are drained and rinsed with a few drops of water passed through the filter into the mixture containing the precipitate. In volumetric estimation the strength of the alkaloidal solu- tion should usually be 1 of alkaloid to 200 of solution a second estimation being made, if need be, for this graduation. The quantity of alkaloid precipitated by 1 c.c., under given condi- tions of concentration, etc., is stated with the directions for quan- titative work on the several alkaloids described in this work. A quite full list of the volumetric factors for Mayer's solution was given by Mayer, and some of these have been subjected to con- trol analyses by Dragendorff and others ; but the presentation of such a list is here intentionally avoided. It must be understood that the alkaloidal equivalent of one c.c. varies with the condi- tions, especially with that of concentration. Unless the analyst has good authority for an alkaloid equivalent, given with speci- fied conditions, he should standardize his Mayer's solution, with an alkaloid solution of known strength, for himself, holding de- grees of concentration, acidulation, mass, and time the same for the titration of the solution of unknown strength that they are for the solution of known strength of alkaloid. The end of the reaction is the point when further addition of the reagent ceases to cause a precipitate. Before this point is reached, however, in some cases the addition of a drop of the solution of the alkaloid will cause a precipitate the mixture having attained a composi- tion of equilibrium (not very rare among chemical reactions) in which precipitation is caused by a drop of either the iodomercu- rate or the alkaloid solution. When the precautions here re- 1 Trials of various indicators for the end-reaction were reported by the author in Am. Chem. Jour , 2, 304, where also attention is called to the error of Mayer's direction to titrate back with silver nitrate. 46 ALKALOIDS. quired are observed, titration with Mayer's solution becomes a trustworthy means of estimation. The alkaloids can be obtained from their iodomercurate pre- cipitates by triturating the washed precipitate with stannous chloride solution and potassium hydroxide to strong alkaline reaction, and then exhausting with ether or chloroform or ben- zene as a solvent for the alkaloids. Strong alcohol can be used as a solvent if potassium carbonate be taken instead of potassium hydroxide. Also, the mercury can be removed from the precipi- tates by dissolving in alcohol, adding acid if need be, treating with hydrogen sulphide gas, and filtering. The filtrate can be freed from iodine, if this be desired, after expelling the hydrogen sulphide, by adding some excess of silver nitrate solution, filter- ing, adding hydrochloric acid to the filtrate, and filtering again . (3) Pliospliomolybdate? A fixed alkali phosphomolybdate in strong nitric acid solution in effect a solution of phosphomo- lybdic acid. Applicable in acidulous solutions and in absence of ammo- nium salts and free ammonia, which also precipitate it. It is prepared as follows : The yellow precipitate formed on mixing acid solutions of ammonium molybdate and sodium com- mon phosphate the ammonium phosphomolybdate is well washed, suspended in water, and heated with sodium carbonate until completely dissolved. The solution is evaporated to dry- ness, and the residue gently ignited till all ammonia is expelled, sodium being substituted for ammonium. If blackening occurs, from reduction of molybdenum, the residue is moistened with nitric acid and heated again. It is then dissolved with water and nitric acid to strong acidulation ; the solution being made ten parts to one of the residue. It must be kept from contact with vapor of ammonia, both during preparation and while pre- served for use. The precipitates of alkaloids, by adding this reagent to their acidified solutions, are amorphous, and of yellowish colors, some- times orange-yellow, in other cases brown-yellow. In general they have very little solubility, and are obtained in very dilute solutions. Besides ammonia, other bodies not alkaloids are liable to give precipitates with this reagent. A negative result is trust- worthy for the exclusion of more than traces of alkaloids in the solution tested. Most of the precipitates are soluble in ammonia, and those of alkaloids that are strong reducing agents mostly dis- 1 SOXNENSCHEIN. 1857: Ann. Chem. Pliar., 104,45. DE VRIJ: Jour, de P/tann., 26, 219. STRUVE, 1873: Zeitscli. anal. Chem., 12, 170. GENERAL REAGENTS. 47 solve with the blue color of reduced molybdic acid, or with some shade caused by admixture of blue. The ammoniacal solution is blue with aconitine, aniline, atropine, berberine, morphine, nicotine, and physostigmine. Alcohol and ether do not dissolve the precipitates, and acetic acid has but a slight solvent action. The alkaloids can be recovered from the precipitates by add- ing potassium or sodium hydroxide solution, and shaking out with an immiscible solvent for the alkaloid, as ether, chloroform, benzene, or amyl alcohol. Adding potassium carbonate instead of hydroxide, strong alcohol can be added instead of an immis- cible solvent. A gravimetric value of the phosphomolybdate precipitate has been obtained for a few of the alkaloids, but it has not been ascertained what conditions are necessary to secure a constant composition. 1 (4) Bromine in aqueous kydrobromic acid. WORMLEY di- rects the use of aqueous hydrobromic acid saturated with bromine. Applicable to aqueous solutions of the salts of the alkaloids, neutral or slightly acidulous witli a mineral acid, and in absence of acetic acid and of alcohol, which dissolve the precipitates. Besides alkaloids, the phenols and other bodies give precipitates with bromine. (See Phenol.) The limit of precipitation of the alkaloids is at dilution to from 5000 to 100000 parts with mor- phine, 1 to 2500 ; with nicotine or conine, 1 to 10000 ; with aco- nitine, codeine, or brucine, 1 to 25000 ; with strychnine, narco- tine, or veratrine, 1 to 100000 (WORMLEY). In general the pre- cipitates are amorphous ; with atropine, crystalline. (5) Potassium cadmium iodide (MARME, 1866). Prepared by saturating a boiling concentrated solution of potassium iodide with cadmium iodide, and adding an equal volume of cold-satu- rated solution of potassium iodide. In diluted solution, precipi- tation is apt to occur. This reagent precipitates the aqueous so- lutions of alkaloid salts, acidified by sulphuric acid, the precipi- tates being soluble in excess of the precipitant, or in alcohol. Amorphous at first, the precipitates become crystalline. The al- kaloids can be recovered from the precipitates as directed for those formed by potassium mercuric iodide. (6) Potassium bismuth iodide (DRAGENDORFF, 1866). Pre- pared from bismuth iodide, in the way directed for the last- 1 It appears probable that a dilute solution of the phosphomolybdate, standardized by solution of an alkaloid of known strength, could be used to estimate the quantity of the same alkaloid under strictly parallel conditions. The end-reaction can bo found as directed for Maver's solution. 48 ALKALOIDS. \ ir named reagent. Cannot be diluted. Applicable as a precipitant to aqueous solutions of alkaloid salts, strongly acidified with sulphuric acid. (7) Metatungstic acid, Phosphotungstic acid (SCHEIBLER, I860), Silicotungstic acid (GODEFFROY, 1876), and Phospho-anti- monic acid (SCHULTZE, 1859), have been used as general preci- Eitants for the alkaloids. GODEFFROY (1877) uses a solution of 3rric chloride in hydrochloric acid as a precipitant for alkaloids. (8) Tannic acid (BERZELIUS, HENRY, DTJBLANC, HAGER), in solution with 8 parts of water and 1 part of alcohol, gives whitish, grayish-white, or yellowish precipitates with nearly all the alka- loids. In the larger number of instances these precipitates are easily soluble in acids, frequently dissolving in excess of the tannic acid ; on the contrary, some of the alkaloids are precipitated by tannic acid only in strong acid solutions. Ammonia dissolves the tannates of the alkaloids. Dilute acetic acid dissolves the precipitates of tannates- of aconitine, brucine, caffeine, colchicine, morphine, physostigmine, and veratrine ; acetic acid not dilute, the precipitate of quinine. Cold dilute hydrochloric acid does not dissolve the precipitates of tannates of aconitine, berberine, brucine (dissolves sparingly), caffeine, cinchonine, colchicine (dissolves slightly), narcotine, papaverine, thebaine, solanine, strychnine (dissolves slightly), veratrine. Cold dilute sulphuric acid does not dissolve the pre- cipitates of tannates of aconitine, physostigmine, quinine, sola- nine, veratrine. Precipitates are completely formed in solutions strongly acidulated with sulphuric acid, by aconitine, physostig- mine, and veratrine, though none of these alkaloids gives a full precipitate in slightly acidulated solution. Alkaloids are recovered from their tannates by mixing the moist precipitate with lead oxide or carbonate, drying the mixture, and extracting with an immiscible solvent or with alcohol. (9) Picric acid, HC 6 H 2 (NO 2 ) 3 O (WORMLEY, 1869 ; HAGER, 1869). Used in very dilute, saturated aqueous solution, or in a sparing addition of the alcoholic solution. Applied as a preci- pitant of alkaloids in their neutral solutions, or, better, in solu- tions acidulated with sulphuric acid. Many of the precipitates become crystalline, and give characteristic forms under the mi- croscope ; 'in general they have a yellow or yellowish-white color. With morphine the precipitate is formed, in drop-tests, in solu- tion of 1 to 500 ; with aconitine, atropine, or veratrine, in solu- tion of 1 to 5000 ; with brucine or narcotine, in a solution of GENERAL REAGENTS. 49 1 to 20000 ; with strychnine, 1 to 25000 ; with nicottne, in solution of 1 to 4000 (WORMLEY). The alkaloids can be re- covered from their picrate precipitates by adding an alkali solu- tion and exhausting with a solvent immiscible with water, or by evaporating to dryness with a solution of potassium or sodium carbonate, and extracting with alcohol. HAGER has used preci- pitation with picrate in some estimations of alkaloids. For cinchona alkaloids, 1 10 grams of the powdered bark, covered with 130 c.c. water, with 20 drops of caustic potassa solution of s.g. 1.3, are digested at boiling temperature and stirred for a quarter of an hour. Of dilute sulphuric acid, s.g. 1.115, 15 grams are added, and the mixture boiled 15 to 20 minutes. When cold the whole is made up, by the addition of water, to 110 c.c. (" the volume of 110 grams of water "). The mixture is filtered, through a paper filter of 10.5 to 11 centimeters (8J inches) diameter, into a graduated jar, and the volume of the filtrate (about 60 c.c.) noted. To this filtrate (100 c.c. of which represents the 10 grams of bark) picric acid solution saturated in the cold is added, in quantity about 50 c.c., or enough to complete the precipitation (as ascertained by allowing a few drops to flow down the side of the vessel). After half an hour the precipitate is gathered on a weighed filter, washed, and dried between blotting-papers over the water-bath. The dried preci- pitate of picrates of cinchona alkaloids contains (according to Hager) two molecules of picric acid as anhydride, 440 parts, to one molecule of cinchona alkaloid, 308 to 324 parts, without water of crystallization. Or 8.24 parts of the precipitate indi- cate about 3.5 of mixed cinchona alkaloids. Then the noted number of c.c. of decoction taken : 100 : : the indicated quan- tity of mixed alkaloids in the precipitate : x =. quantity mixed alkaloids in the 10 grams of bark. (10) Platinic Chloride. Auric Chloride. Solutions of these salts, hardly to be classed as special reagents for alkaloids, yet give precipitates with the greater number of them. Platinic chloride is often required in establishing distinctions between alkaloids, as noted in this work under the qualitative reactions of the respective compounds. The same may be said of auric chloride. The melting points of the alkaloidal compounds of these metals serve as constants useful for identification, especially in distinguishing the derivatives of alkaloidal radicals. The composition of these metallic precipitates has in most cases been 'I860 : PJiar. Centralh., p. 145 ; Zeitsch. anal. Chem., 8, 477. 50 ALKALOIDS. estimated from the percentages, respectively, of metallic platinum and metallic gold, left after ignition. These percentages were much depended upon in the earlier years of the chemistry of the alkaloids, and are given full and prominent statements in Gme- lin's Hand-book of Chemistry. The platinum precipitates are divisible into those which do and those which do not dissolve in hydrochloric acid cinchonine and quinine, morphine, and strychnine being placed among those not readily soluble in this acid. The platinum precipitates have a yellow or yellowish color. The gold precipitates of a number of the alkaloids blacken by reduction on standing. Color-reactions of the Alkaloids. In general it should be borne in mind that color-reactions are subject to variation (1) by impurities of the alkaloidal material, (2) by impurities of the reagent, and (3) by conditions of concentration, mass preponde- rance, temperature, and time. Also, that the best authority to guide the operator is the result of a control-test upon a known portion of the alkaloid in question, holding all conditions to be the same. Concentrated Sulphuric Acid 1 dropped upon the dry alka- loid, on a white porcelain surface or on glass over a white ground, without heating, reacts as follows : colorless with atro- pine, caffeine, chelidonine, cinchonidine, cinchonine, codeine, nyoscine, hyoscyamine, morphine, nicotine, pilocarpine, quini- dine, quinine, staphisagrme, strychnine, theobromine. Of these, on warming, a purplish to brown color is given by morphine. Yellowish colors are given by colchicine, gnoscopine, and jer- vine ; reddish colors are given (either at once or after a short time) by apomorphine, brucine (pale rose), conine (pale), gelse- niinine, meconidine, narceine (to black), narcotine (yellow-red to violet and blue), nepaline, physostigmine, rhoeadine, sabadilline, sabatrine, solanine, taxine, thebaine, veratrine, and veratroidine ; bluish colors are given by cryptopine, curarine (on standing), and papaverine ; and greenish colors by beberine, berberine, emetine (brown to green), piperiiie, pseudomorphine, and rhoeadine. Of glucosides, reddish colors ^mostly bright) are given by ainygda- lin, colombin, cubebin, elaterin, hesperidin, phloridzin, populin, saliciii, sarsaparillin, senagin, smilacin, syringin, tannic acids. 1 Traces of nitric acid, not infrequent as an impurity in " C. P. sulphuric acid," cause a great difference in the reaction with morphine and other alka- loids colored by nitric acid. See the composition of " Erdmann's reagent," given in the foot-note under Nitric Acid Color Tests. On the Reactions of Alkaloids with Sulphuric Acid, cold, warm, and hot alone, with nitric acid, jind with permanganate see GUY, 1861-2: Phar. Jour. Trans, [2], 2, 558, 662 ; 3. 11, 112 ; Zeitsch. anal. Chem., i, 90. GENERAL REAGENTS. 51 Froelidds Reagent concentrated sulphuric acid containing molybdic acid. 1 A solution of 0.001 grain of molybdic acid or alkali molybdate, in 1 c.c. of concentrated sulphuric acid (DuA- GEXDORFF), freshly prepared by the aid of heat, and used when cold. FROEHDE took 0.005 gram of the molybdate to 1 c.c. of sulphuric acid, and BUCKINGHAM took as much as 1 part of molybdate to 15 of the sulphuric acid ; but the more attenuated proportion of the molybdate (1 to 1840) gives the more dis- tinctive reactions. The reduction of molybdic acid to hydrated molybdic molybdate is attended with a bright blue color. This reduction occurs in concentrated sulphuric acid, by heat alone, at the temperature of incipient vaporization of the sulphuric acid. Numerous inorganic and organic reducing agents cause the reduction and give the color to molybdate. As a character- izing reaction it is applied mostly to alkaloids, when non-alka- loidal matter must be excluded, and the more dilute solution of molybdate is the more trustworthy. Froehde's reagent gives no color with atropine, caffeine, cin- chonidine, cinchonine, conine, delphinine, hyoscine, hyoscya- mine, nicotine, strychnine, theobromine ; yellowish colors with aconitine, colchicine, piperine ; reddish colors with brucine, eme- tine (red changing to green), narceine (changing to blue), saba- dilline (reddish-violet), solanine, thebaine (orange), veratrine (gra- dually, cherry-red) ; bluish colors with codeine (gradually, deep blue), morphine (violet to blue), narceine (yellow-brown* to red and blue), staphysagrine (violet-brown) ; greenish colors with apomorpliine (green to violet), beberine (brown-green), berberine (brown-green), emetine (red changing to green and turned blue by hydrochloric acid), quinine (pale), quinidine (pale). Of glu- cosides, colocynthin gives slowly a cherry-red color ; elaterin, yellow ; phloridzin, slowly, blue ; populin, violet ; salicin, violet to cherry-red ; syringin, blood-red to violet-red colors. Nitric acid, of s.g. 1.40 to 1.42, applied in a drop to the dry alkaloid upon white porcelain, gives a color, frequently reddish, with numerous alkaloids. No color is obtained with atropine, caf- feine, cinchonidine, cinchonine, conine, gelseminine, quinidine, quinine, strychnine, theobromine. Yellowish colors are obtained 1 FROEHDE, 1866: Archiv der Phar., 126, 54; Zeitsch. anal. Chem., 5, 214; Pro. Am. Pharm., 15, 241. ALMEN, 1868: N. Jahr. /. Phar., 30, 87; Zeitsch. anal. Chtm., 8, 77. KAUZMANN, 1869: Zeitsch. anal. Chem., 8, 105. BUCK- INGHAM, 1873: Jour. Chem. Soc., 27, 715; Am. Jour Phar., 45, 179. DRAGEN- DORFF, 1872: " Beitrage zur gericht. Chem. organ. Gifte." A. B. Prescott. 1876: " Froehde's Reagent as a Test for Morphine," Am. Jour. Phar., 48, 59; Jn.hr der Pharm., 1876, 502. On various reactions of the blue oxide of molyb- denum, see MASCUKE, 1878. 52 ALKALOIDS. with aconitine (yellow to brown or red, variable), codeine (orange-yellow), morphine (yellow to red), narceine, narcotine, papaperine (orange), piperine (orange), rhoeadine', sabadilline (yellow), thebaine, veratrine. Red colors are obtained by aconi- tine (red-brown, variable), apomorphine, berberine (red-brown), brucine (blood-red), papaverine (orange-red), pseudomorphine (orange red), physostigmine. A blue color is given by colchi- cine and by solanine (Dragendorff). - Some glucosides give bright colors ; ligustrin and syringin, blue tints. Sulphuric acid (concentrated), followed by a minute addi- tion of nitric acid (s.g. 1.40-1.42), or of solid potassium nitrate. 1 No color is given by atropine, caffeine, cinchonidine, cinchonine, nicotine, pilocarpine, quinidine, quinine, staphysagrine, strych- nine, theobromine. Red colors are given by brucine, curarine, narcotine (red-violet), nepaline, pbysostigmine, sabadilline, the- baine, veratrine (gradually, cherry-red). A violet color is given by morphine (under directions specified for that alkaloid). Co- deine gives a succession of colors, as also does colchicine. Sulphuric Acid and Cane Sugar* The substance to be tested, in the dry state, is mixed with 6 to 8 parts of cane-sugar, and a few milligrams of the mixture are placed upon a drop or two of concentrated sulphuric acid, over a white ground. The gradual browning of the sugar itself is disregarded, and will be covered by the bright colors of characteristic reactions. No colors are given by atropine, brucine, caffeine, cinchonidine, cin- chonine, conine, nicotine, quinidine, quinine, strychnine, and theobromine. Reddish colors are given by codeine, curarine, gelseminine, morphine (purple-red, then blue-violet, dark blue- green, and lastly blackish-yellow limit 0.0001 to 0.00001 gram), nepaline (gradually), sabadilline (red dish- violet). A bluish color by veratrine. Various oils, and albuminoids, give bright colors with sulphuric acid and sugar. Hydrochloric Acid, concentrated, gives colors with only a few alkaloids. Reddish colors are given by physostigmine, sabadilline, and veratrine. 1 ERDMANN, 1861: Ann. Pharm. Chem.. 120; Zeitsch. anal. Chem., I, 224. Erdmann mixed six drops of nitric acid of s.g. 1.25 with 100 c.c. of water, and added ten drops of this mixture to 20 grams of sulphuric acid. Of this " Erdmann's reagent '"8 to 20 drops were added to 1 or 2 milligrams of the solid to be tested, and the color noted after $ to | hour. HUSEMANN, 1863: Ann. Chem. Phar., 128, 308 the well-known test for morphine. DRAGEN- DORFF, 1868: " Ermittelung von Giften." p. 239. * SCHNEIDER, 1872: Ann,. Phys. Chem. Pogg., 147, 128; Zeitsch. anal. Chem., 12, 218. Respecting reactions with substances not alkaloids, SCHULTZE, Ann. Chem. Phar., 71, 266. MICROSCOPICAL CHARACTERISTICS. 53 Other Reagents for alkaloids as a class, or for groups of alka- loids. Iodine in hydriodic acid, gold bromide, sodium gold thiosulphate, potassium gold iodide, lead tetra-cliloride, and manganese perhydroxide in sulphuric acid, were reported upon by F. SELMI in 1877. Perchloric acid, FKAUDE, 1879-1880. Sodium arseniate with sulphuric acid, TATTERSALL, 1879. Cu- piic ammonium hydrate, NADLER, 1874. Ferric chloride and sulphuric acid, How, 1878. Fused antimonious chloride, SMITH, 1879. Nitroferricyanide of sodium, as a precipitant, HORSLEY, 1862. The Microscopical Characteristics of alkaloids, in their various combinations, receive attention to some extent in all chemical literature upon these bodies, and in the description of the several alkaloids in this work. Among the special contri- butions are the following : HELWIG, 1865 : " Das Microscop in Toxicologie." GODEFFROY and LEDERMANN, 1877 : on cinchona alkaloids. WORMLEY, 1885 : " Microchemistry of Poisons," 2d ed., Philadelphia. A. PERCY SMITH, 1886 : identification of alka- loids by crystallization under the microscope, Analyst, II, 81. On MicrosuHimation of Alkaloids : HELWIG, 1864: Zeitsch. anal. Chem., 3, 43; "Das Microscop in Toxicologie," 1865. GUY, 1867 : Phar. Jour. Trans., [2], 8, 718 ; 9, 10, 58, 106, 195, 370; " Forensic Medicine," London, 1875. STODDART, 1867. ELLWOOD, 1868. BLYTH, 1878 : Jour. Chem. Soc., 33, 313. In this work, see under Caffeine. The Subliming Cell of Dr. Guy, improved by Blyth, consists essentially of a ring of glass, about ^ inch in thickness, or from \ to f inch. This glass ring rests on an ordinary " cover-glass " a thin disc used under this name in microscopy. Another cover-glass is placed upon the ring, which is of a diameter to fit the cover- glasses, and with them make a closed cell. The ring can be made of a section of glass tubing by grinding the edges. The cell, so constituted, was heated by Dr. Guy through a brass plate on which it rested. Dr. Blyth prefers to rest the cell upon liquid metal, using mercury for tem- peratures below about 100 C., and fusible metal for tempera- tures above this point. The liquid metal is contained in a porcelain capsule of about 3 inches diameter, supported on the ring of a retort-stand, and heated directly by the flame. A flask of suitable size, from which the bottom has been removed, is placed over the capsule, upon the ring of the retort-stand, and made to carry the thermometer, held in a perforated stopper and with its bulb immersed in the liquid metal by the side of the subliming cell. A minute speck of the article tested is placed 54 ALOINS. on the lower disc of the cell. Blyth's definition of a sublimate is this : " The most minute films, dots, or crystals, which can be observed by a quarter-inch power, and which are obtained by keeping the subliming cell at a definite temperature for sixty seconds." ALOINS. Varieties of a neutral crystalline principle ob- tained from the several kinds of aloes. As first described (T. & H. SMITH, 1851), it was obtained from Barbadoes aloes, and was the body now named barbaloin. There have been described : SOM MA RUG A and Aloes. Yield. 1 EGGER, 1874. Barbaloin Barbadoes 20-25 per cent. , at most, Ci7H 3 o0 7 TILDEN, 1872. Nataloin Natal 16-25 percent., at most, C 16 H 18 7 Socaloin Socotrine 3 per cent, average, CiaHieOr Zanzibar PLEXGE, 1885. TILDEN ascribes to barbaloin the formula C 34 H 36 Oi 4 . IL,O, and to nataloin C^HggO-n ; and FLUCKIGER (1871) obtained for socaloin C 34 H 38 O 15 . 5H 2 O. Aloins are identified by their color-reactions with nitric and sulphuric acids, by which, also, and by production of chrysammic acid, they are distinguished from each other (d). ALOES is found in mixtures by treatment with acids, or by extraction with amyl alcohol and treatment with various reagents (^, p. 55). Chrysammic Acid, p. 56. As to physiological effects, with reference to valuations, &, p. 55. a. Barbaloin, crystallized from a concentrated aqueous solution of Barbadoes aloes, appears in tufts of small yellow prisms, losing 2.69 per cent, of water by drying at 100 C. or in vacuum. Nataloin exists in a crystalline state in Natal aloes, from which it is left on treating with an equal portion of alcohol at 48 C. or under, and when recrystallized forms thin, brittle, rectangular scales with some of their angles truncated. It loses no water at 100 C. Socaloin exists in Socotrine or Zanzibar aloes in prisms of good size ; when recrystallized from methyl alcohol, tufted acicular prisms, which may be obtained 2 to 3 millimeters long. At 100 C. it loses about 12 per cent, of water. J. Aloins are without odor and have the taste of aloes. Their purgative power has been questioned, and while they have 1 Of 18 varieties of aloes, yields of from 2.2 to 31.3 per cent, were ob- tained: DRAGEXDORFF, 1874: " Werthbestimmnng." A LOINS. 55 had some little medicinal use as therapeutic representatives of aloes, more in Great Britain than elsewhere, yet this use has not extended, although aloin is more agreeable for administration than the aloes from which it is extracted. DRAGENDORFF states (1874: " Werthbestimmung "), on experimental data, that (1) the resins of any variety of aloes, separated as insoluble in cold water, in doses of 0.35 gram (5 to 6 grains), prove inactive ; (2) that perfectly pure aloins, in doses of 0.3 to 0.5 gram (5 to 7 grains), prove inactive with many persons ; and (3) that the so- called aloes-bitter, soluble in cold water and containing either amorphous aloin or oxidized products, represents the activity of the drug ; also (4) that the purgative power of an aloes is measured by the quantity of bromaloin precipitated from an aqueous solution of the drug, also by the quantity of precipi- tate by tannic acid. Dragendorff infers that aloin is converted into bodies having the purgative action of aloes. TILDEN (1876) found that all three aloins are decidedly uncertain and variable in their action, and seem to present no advantage over an equal dose of- aloes, except perhaps that griping was rather less com- mon under their use. c. The aloins are soluble in water, barbaloin the most freely of the three, socaloin in about 90 parts, and nataloin very spar- ingly. Alcohol dissolves all the aloins, socaloin requiring about 30 parts, and nataloin about 60 parts (230 parts absolute alcohol). In ether aloins are but slightly soluble, though socaloin dissolves in about 380 parts. Aloin " from the different varieties of aloes " is described in Br. Ph. (1885) as " sparingly soluble in cold water, more so in cold rectified spirit, freely soluble in the hot fluids. Insoluble in ether." d. Nitric acid (s.g. near 1.40 or 1.42), applied to the dry aloin on a porcelain slab, gives a bright red color with barbaloin or nataloin, not with socaloin. The crimson red of barbaloin fades quickly ; the blood red of nataloin does not fade unless heated (HISTED, 1871 ; TILDEN, 1876). Boiling with nitric acid produces chrysammic acid, C 14 H 4 (ITO 2 ) 4 O 2 (tetranitrodioxyan- thraquinone), of intense red color, from both barbaloin ' and nataloin, not from socaloin. Oxalic and picric acids, in addition, are obtained from barbaloin by action of boiling nitric acid (distinction from socaloin or nataloin). If nataloin be wet with concentrated sulphuric acid, and then touched by the vapor of strong nitric acid from a glass rod or by a minute fragment of potassium nitrate, a fine blue color is obtained (distinction from barbaloin or socaloin). Concentrated sulphuric acid, applied to 56 AMYGDALIN. the dry substance, and followed by a minute fragment of potas- sium dichromate (as in the fading purple test for strychnine), causes a green or greenish-purple color, changing to greenish- yellow. Alkalies cause the decomposition of aloins. Solu- tions of aloes, too, lose their bitterness and their purgative power when made alkaline (G. MCDONALD, 1885). CHKYSAMMIC ACID (see above) crystallizes in gold-glittering needles, or in yellow fern-leaves resembling picric acid. It de- tonates on heating. It is acidulous in reaction, and of intensely bitter taste. It is insoluble in cold water, easily soluble in alco- hol and in ether. It forms colored salts with metallic lustre. Potassium chrysammate crystallizes with bright green lustre, or (from acid solutions) as bright crimson needles with a slight golden reflection. ALOES. If a grain of aloes or dry mixture be dissolved in 16 drops of strong sulphuric acid, 4 drops of nitric acid (s.g. 1.42) added, arid the mixture diluted with one ounce of water, a deep orange or crimson color will be obtained. On adding ammonia the color changes to a claret. All substances containing chry- sammic acid behave nearly the same in this test, except that they turn pink on adding ammonia directly to their aqueous solutions, while the solutions of aloes do not (CEIPPS and DY- MOND, 1885). If a fluid containing aloes be extracted with amyl alcohol, the residue left by evaporating this solvent will have a bitter taste, and when this residue is dissolved in water the solu- tion will give precipitates with bromine in potassium bromide solution, basic lead acetate, rnercurous nitrate, and tannic acid, and will reduce gold chloride and Fehling's solution. The dry residue will give a blood-red color with potassium cyanide and hydroxide (DKAGENDOKFF, LENZ, 1882). AMYGDALIN. Co^-NO^ = 457 (LIEBIG and WOHLER, 1837). C 12 H 14 O 4 .(OH) 7 .C 7 H 6 .CN (SCHIFF, 1870). A gluco- side which occurs in the bitter almonds and in numerous other plants which yield hydrocyanic acid by natural fermentation. The bitter almonds, after removal of the oil by pressure, are di- gested twice with hot 95$ alcohol, and allowed to stand for some time. The alcohol is decanted and concentrated to a syrup, from which the amygdalin is precipitated by ether. The precipitated amygdalin is washed with ether and recry stall ized from boiling alcohol. Amygdalin crystallizes from alcohol in colorless scales anhy- drous or with 2H 2 O, from water in transparent prisms, becoming opaque in the air, and containing 3HoO. It becomes anhydrous ARBUTIN. 57 at 110-120 C. It is odorless, of a slightly bitter taste and neutral reaction, and rotates the plane of polarization to the left. It is soluble in any proportion of hot and 12 parts cold water; in 11 parts boiling and 904: parts cold alcohol (s. g. 0.819) ; in 12 parts boiling and 148 parts cold alcohol (s. g. 0.939) ; insoluble in ether. Concentrated sulphuric acid dissolves it with violet-red color, which turns black on warming. The other mineral acids decompose it. In contact with emulsin and water (10 parts amygdalin, 1 part emulsin, and 100 parts water) it is changed into benzoic aldehyde (oil of bitter almonds), hydrocya- nic acid, and glucose, as follows : C 20 H 2T NO n +2H 2 O=:C 7 H 6 O+HC]S"+C 12 H 24 O 12 . Through farther change of the hydrocyanic acid, formic acid also is formed. By boiling with dilute sulphuric acid the same reaction takes place, when formic acid is always formed. 17 parts of anhydrous amygdalin, or about 24 to 25 parts (theoretical- ly, 19 parts) of the ordinary commercial amygdalin, yield, when fermented with emulsin, one part hydrocyanic acid and 8 parts bitter- almond oil. Boiling amygdalin with aqueous alkalies or baryta changes it to ammonia and amygdalic acid (C 20 H 26 O 12 ). ANALYSIS, ELEMENTARY. See ELEMENTARY AN- ALYSIS. ANALYSIS OF PLANTS. See PLANT ANALYSIS. ANALYSIS, ORGANIC. See ORGANIC ANALYSIS. ARBUTIN. C 12 H 16 O 7 = 272. A glucoside found (about 3.5$) in the leaves of the bearberry (Arctostaphylos Uva-ursi] arid in a number of other plants, especially in those belonging to the order Ericaceae. It may be obtained by precipitating the decoction with lead subacetate, freeing the filtrate from lead by hydric sulphide, treating with animal charcoal, and crystallizing. Crystallizes in bunches of silky needles which have the com- position (C 12 H 16 O 7 ) 2 .H 2 O. They become anhydrous at 100 C. and melt at 170, have a bitter taste and neutral reaction. Sparingly soluble in cold water, readily soluble in hot water and in alcohol ; slightly soluble in ether. Boiled with dilute sulphuric acid, or subjected to the action of emulsin or another ferment contained in the bearberry, it is converted into hydro- quinone, C 6 H 6 O 2 ,' and glucose. Treated with manganese diox- ide and sulphuric acid, it is oxidized to quinone, C 6 H 4 O 2 , and formic acid. It does not reduce alkaline cupric solution, and is 58 ASPARAGIN BEBIRINE . not precipitated by salts of the metals. Concentrated sulphuric acid dissolves it without color. Nitric acid turns it black, gradu- ally dissolving it to a yellow solution. If an aqueous solution be rendered alkaline with ammonia and then phosphomolybdic acid added, it becomes blue [one part in 140,000 parts water gives a distinct color JUNGMANN, 1871 : Am. Jour. Phar., 43, 205]. ARICINE. See CINCHONA ALKALOIDS. ASPARAGIN. C4H 8 K 2 3 =132. Amido-succinamic Acid. Exists already formed in asparagus (Asparagus officinalis) and a great many other plants. It crystallizes from the cold water ex- tract of asparagus upon concentration to a thin syrup, and may be purified by treatment with animal charcoal and recrystalliza- tion from hot water. The crystals are hard, brittle, transparent prisms of the tri- metric system having the composition C 4 H 8 N 2 O 3 . H 2 O. They are odorless, have a slight, disagreeable taste, are permanent in the air, and become anhydrous at 100 C., above which temperature they are decomposed. Asparagin is soluble in 58 parts cold and 4.4 parts boiling w^ater ; in 500 parts cold and 40 parts boiling 60$ alcohol ; in 700 parts boiling 98$ alcohol ; insoluble in abso- lute alcohol, chloroform, ether, and benzene ; easily soluble in acids and aqueous alkalies. It forms weak compounds with both acids and alkalies. In contact with the accompanying extractive substances, yeast or casein, etc., it is changed by fermentation into succinate of ammonium (sometimes with the intervening formation of aspartate of ammonium). When boiled with acids or alkalies it is resolved into aspartic acid (C 4 II 7 NO 4 ) or amido- succinic acid, and ammonia. Respecting the quantitative estimation of asparagin, see the current reports of E. SCHULZE, 1881 to 1885. AT RO PINE. See MIDRIATIC ALKALOIDS. BAKING POWDERS. See TARTARIC ACID. BEBIRINE. Bilerine, Ci 8 H 21 NO 3 , dried at 100 C. In Greenhart or Bibirin bark (British Guiana), H. RODIE, 1835 ; as "Buxine" in bark of Buxus sempivirens or Common Box, Faury, 1830, identified with bebirine by Walz in 1860 and Fliickiger in 1869; as Pelosin, in Parei'ra Brava root (Chon- drodendron tomentosum and Cissampelos Pareira),Wiggers, 1839, identified with bebirine by Fliickiger in 1869. BENZOIC ACID. 59 a. A white, amorphous powder, melting at about 145 C., and decomposing at a higher temperature. Its salts of common acids are uncrystallizable, pulverulent or resinous, and white or yellowish- white. &. The alkaloid and its common salts are odorless, with a strong and persistent bitter taste. Its effect is held to resemble that of quinine, and is given in about the same quantities. c'. Very slightly soluble in water (6600 parts cold, 1500 boiling) ; soluble in 5 parts absolute alcohol and 13 parts of ether ; soluble in chloroform, benzene, amyl alcohol, and carbon di sul- phide. Its solutions are strongly alkaline to test-papers. The sulphate^hydrochloride, and acetate are readily soluble in water ; the solutions having a neutral reaction. d. The alkali hydrates and carbonates give precipitates, soluble in excess of the hydrates. Precipitates are caused by potassium mercuric iodide (white), potassium iodide, mercuric chloride, gold chloride (yellow- white), platinic chloride (pale yel- low), and sodium phosphomolybdate (dissolved blue by ammo- nia, decolored by boiling), picric acid (yellow), sulphocyanate (reddish-white). Nitric acid dilute and potassium nitrate give a white precipitate (Fliickiger) ; sodium phosphate, a white precipitate. The pure alkaloid does not reduce iodic acid. e. Bebirine has been. prepared from the different plants in which it occurs, by extraction with acidulated water, and precipi- tation w r ith soda or ammonia, with a precipitate by lead subacetate and extraction therefrom by dilute sulphuric acid (or by digesting the precipitate with magnesia and extracting with alcohol or ether). Purification by animal charcoal is sometimes used instead of, or after, the lead precipitation ; the object in either operation being chiefly removal of resinous matter. f. The precipitated alkaloid loses 8.2 p. c. water (near- ly ifEL,O) at 100 C. Bebirine platinic chloride (C 18 H 01 NO 3 )<> (HdfygPtCL (Bodeker). The Hydrochloride is C 18 H 01 NO 3 . HCL -The" Sulphate (C 18 Ho 1 NO 3 )ol4SO 4 [Maclagen]. BENZOIC ACID. Benzoesaure. Acide Benzoi'que. C~H 6 O 2 =:122 (monobasic). C 6 H 5 .COoH. Carboxyl-benzene. Without isomers. Sources: Benzoic acid is found, nncom- bined, in the proportion of 10 to 19 per cent., in Benzoin, the balsamic resin of Styrax Benzoin, produced in Siarn and Suma- tra ; also in smaller proportions in Balsam of Peru, in Balsam of 60 BEN ZOIC ACID. Tolu ? (Bussj, 1876), in fruit of Vaccinium vitis-idaea (cowberry) (O. Low, 1879), and in the Xanthorrhoea resins. It has been found in certain plums and other fruits. In combination with ethereal bases, forming essential oils, it is found in numerous bal- sams and resins, and in the oils of cinnamon, bergamot, origa- num, and cananga (ylang-ylang). The fragrant oil slightly per- vading the Benzoin is reported to be ethyl benzoate. The benzoates frequently accompany or substitute the compounds of cinnamic acid, and sometimes occur with coumarin. The stiint of sheep's wool contains benzoates (TAYLOR, 1876). Benzoic acid is slowly formed by the atmospheric oxidation of oil of bitter almond (benzoic aldehyde), appears among the oxidation-products of cinnamic acid and various aromatic compounds, and results from certain decompositions of albuminoids. SCHULZE (1885) finds benzoic acid in the heavier (phenol-containing) coal-tar oils. Hippuric acid, in decomposing urine, may change to benzoic acid. Benzoic acid is manufactured (1) from Benzoin, either, as "flowers of benzoin," by direct sublimation, 1 or in the wet way, as "crystallized benzoic acid," by dissolving with lime, precipi- tating from the calcium benzoate solution by adding hydrochloric acid, and recrystallizing from hot w r ater to remove resin. (2) From the Hippuric acid of graminivorous animals, chiefly horses and cows, by concentrating the urine, acidulating with hydro- chloric acid to obtain crystallized hippuric acid, and boiling the latter with crude hydrochloric acid, when benzoic acid and the by-product glycocoll are promptly formed : CH 2 . NHYCO . C 6 H 5 ) . CO 2 H+H O =C 6 H 5 C0 2 H+CH 2 . NH 2 . CO 2 H (3) From the coal-tar product, Naphthalene, C 10 H 8 , which by treatment with nitric acid is converted into phthalic acid. C 6 H 4 (CO 2 H) 2 , when the latter, heated to about 350 C. with its equivalent of calcium hydrate, in absence of air, forms the lime salt of benzoic acid : 2C 6 H 4 (CO 2 ) 2 Ca+Ca(OH) 2 =(C 6 H 5 CO 2 ) 2 Ca+2CaCO 3 . And (4) from Toluene, of the coal-tar distillates, C 6 H-.CH 3 , known as toluol, by formation of trichloro-toluenes (C 6 H 5 .CC1 3 ), and conversion of the latter to benzoic acid. The pharmaco- poeias require the " natural benzoic acid." Of " artificial benzoic 1 LOEWE, 1869, and Rump, 1878, maintain that part of the benzoic acid obtained is not ready formed in the benzoin, but requires to be separated from some combination, or union with another acid. The combination with cinna- mic acid, 2C 7 H 6 02 .C 9 H 8 S , has been reported. BENZOIC ACID. 61 acid " the production from toluol is increasing, and little is made from phthalic acid. (See, further, under Impurities.) BENZOIC ACID may be identified by its behavior in sublima- tion (a), toward solvents and precipitants (c), in reduction to bit- ter-almond oil, and in its reaction with ferric salts (d). From Cinnamic acid it is distinguished by not being oxidized to bitter- almond oil (g) ; from Salicylic acid by the color of the ferric salt. It may be separated (e) by distillation of the free acid (2) or from its salts (1) ; by solution in solvents not miscible with water (3) ; by precipitation as free acid from aqueous solution of its salts (4) ; by sublimation (5) ; from cinnamic acid (7) ; from milk (8) (p. 65). It can be estimated by acidimetry, arid by weight of the free acid, or its lead salt (f). Directions for ex- amination are given (g) as to impurities, accompaniments, and required quality for specific uses, and with regard to the sources of its production. a. Benzoic acid appears in pearly, lustrous, friable, and flexi- ble plates or needles, or in flocculent masses of plate -like or nee- dle-form structure, of hexagonal outline. From dilute alcohol six-sided prisms are obtained. The pure acid is colorless or white ; that sublimed from benzoin is frequently yellowish to yellowish-brown, and this coloration is requisite in the descrip tion of the German pharmacopoeia. The coloration deepens in long keeping. (See g.} The pure acid is permanent in the air. Specific gravity, 1.292, at mean temperature compared with water at 4 C. (SCHRCEDER, 1880). It melts at 121 C. (CAR- NELLY, 1878), and (by same authority) boils at 249 C. (480.2 F.), subliming unchanged. But at 100 C., either dry or with steam, it vaporizes perceptibly, and its vapor irritates the throat and ex- cites coughing. By direct heat, alone, as in a test-tube moved over a flame, it vaporizes without residue, the sublimate, if slowly deposited, crystallizing in needles. The vapors redden litmus paper. From benzoates heated with phosphoric acid, or bisulphate, the same vapors and sublimate may be obtained. Benzoic acid is carried over, to some extent, with vapor of alco- hol, benzene, and other solvents of low boiling points. Boiled with strong alkalies in aqueous solution it suffers change. J. Benzoic acid has a sharp, acid taste, and when pure is without odor. The pharmacoposial acid, from benzoin, has an agreeable aromatic odor, slight in the acid by precipitation, strong in the acid by sublimation, sometimes resembling vanilla, and by authority of the Ph. Germ, somewhat empyreumatic. 62 BENZOIC ACID. That from toluol often has an almond odor; that from hippuric .acid a urinous odor. The medicinal dose of benzole acid does not overgo 20 grains. Locally it sometimes causes mucous irri- tation. In the human body benzoic acid is converted into hip- puric acid, the reaction being the reverse of that given above (p. 60), and excreted in the urine. If large quantities of ben- zoic acid be administered, a portion may be carried into the urine without change. Benzoic acid is an efficient antiseptic and antiferment, more powerful than salicylic acid. ARCHER (1878) used, for infusions, saccharine liquids, etc., about 4 grains to one pound, or near 0.06 per cent. ECCLES (1885) estimates about 0.04 per cent, to be sufficient for hypodermic medicated liquids. c. Benzoic acid dissolves in water as follows (BOURGOIN, 1879) : at 15 C. (59 F.) in 408 parts ; at 20 C. (68 F.) in 345 parts ; in 17 parts of boiling water. In 500 parts water of ordi- nary temperature (Fluckiger*s Phar. Ohem.) In 372 parts water (Phar German.) In 333 parts at 15 C. ; 250 parts at 20 C. (Hager's Commentar., 2d ed.) In 2 to 3 parts of al- cohol of ninety per cent. ; in 2.2 parts absolute alcohol; in 1 part of boiling alcohol. In 2 to 3 parts of ether ; 7 to 8 parts of chloroform ; 8 parts of benzene. Freely in petroleum benzin, amyl alcohol, and dissolves in volatile oils and in fixed oils. Benzoic acid has a decided acid reaction to test-papers, and causes effervescence in aqueous solutions of carbonates. Carbon dioxide decomposes alkali benzoate in alcoholic solution, causing a precipitate of alkali carbonate. The metallic benzoates are normal salts of a good degree of stability. Ferric benzoate be- comes in part basic in water, and mercurous benzoate in hot water forms mercury and mercuric benzoate. Both the normal and basic lead salts are obtained. The normal benzoates are either freely or moderately soluble in water ; those of lead, sil- ver, and mercury being sparingly soluble in hot water, but pre- cipitated by adding solutions of alkali benzoate to the metallic salt solutions in the cold. Alcohol dissolves most benzoates sparingly or freely; it decomposes the benzoates of mercury. BENZOATE OF SODIUM crystallizes, with one aq., in slightly efflo- rescent needles ; from a drop of alcoholic solution, in microsco- pic star-form groups. The salt dissolves, with a neutral reac- tion, in about 2 parts cold water, and in 13 parts of 90# alcohol, not in ether or chloroform. Ammonium benzoate crystallizes anhydrous ; it loses ammonia and acquires free acid when ex- posed to the air. Calcium benzoate crystallizes in feathery nee- BEN ZOIC ACID. 63 dies, with four molecules of water, efflorescent, and soluble in 20 parts of cold water. Cinchonidine benzoate, normal, forms short prisms, anhydrous, soluble in 340 parts of water at 10 C. Benzoates of methyl and ethyl are colorless, oily liquids, sinking in water, of pleasant and balsamic odors, boiling respectively at 199 and 212 C., not more than slightly soluble in water, freely soluble in alcohol. d. Aqueous solutions of benzoates, by addition of hydro- chloric acid or sulphuric acid,' give a voluminous, crystalline, white precipitate of benzoic acid, subject to its solubilities as stated above (c). Ferric chloride solution, in a neutral benzoate solution, gives a flesh-colored, voluminous precipitate of basic ferric benzoate, formed more quickly if the reagent be slightly basic. The precipitate is not readily dissolved by acetic acid. Free benzoic acid, in excess of saturated solution, is slowly pre- cipitated by the normal iron salt. If the solution tested be strongly alkaline in reaction, a misleading brown precipitate of ferric hydrate may occur. The ferric succinate precipitate is red-brown. Silver nitrate, in neutral solution of a benzoate, forms a voluminous white precipitate of silver benzoate, soluble in hot water, then crystallizing on cooling, somewhat more solu- ble in alcohol, dissolved by acetic acid, also by ammonia, not ob- tained with free benzoic acid. Acetate of Lead, in neutral solution of a benzoate, not too dilute, gives a white precipitate of lead benzoate, somewhat soluble in excess of the reagent, soluble in hot water, dissolved by acetate of ammonium, not by ammonia. Treatment with hydric sulphide resolves the pre- cipitate into lead sulphide and free benzoic acid, the latter being separated by hot filtration or by help of alcohol. Also, if the lead benzoate be boiled with a requisite quantity of sodium sul- phate, transposition of the metals is effected, and a filtrate of so- dium benzoate may be obtained. Barium chloride and calcium chloride give precipitates only in concentrated solutions of alkali benzoates, but the precipitation is promoted by free addition of alcohol. Metallic magnesium, or aluminium, or sodium-amalgam, in solution of benzoic acid or benzoate, acidulated with only enough sulphuric acid to cause a moderate evolution of hydrogen, on standing from half an hour to several hours, effects the reduc- tion to benzoic aldehyde (C 6 H 5 . COH), bitter-almond oil, recog- nized by its odor. This distinctive reduction is also obtained by passing the dry vapors of benzoic acid through faintly ignited zinc-dust. Heated, with two or three parts of lime or with so- 64 BENZOIC ACID. dium or potassium hydrate, in a small distilling apparatus, a dis- tillate of benzene is obtained: C 6 H 5 CO 2 H:=CH e +CO 3 . With concentrated sulphuric acid, pure benzoic is not colored, but is dissolved. If glucose be present a blood-red color is obtained, as noted under Salicylic Acid, d. Pure benzoic acid does not discolor the permanganate solution, nor reduce the potassium cupric (Fehling's) solution when heated, nor blacken ammonia- silver nitrate. e. Separation. (1) Water cannot be evaporated from free benzoic acid without its serious waste, and it suffers a slight loss in evaporation of its solutions in alcohol, benzol, etc. For the concentration of its aqueous solution it is to be neutralized by adding just enough sodium carbonate. Ammonia is not re- tained in full combination. (2) Small quantities of free benzoic acid may be distilled over with water, and for this purpose ben- zoates may be decomposed by adding enough sulphuric acid. (3) Free benzoic acid may be obtained from any aqueous liquid by shaking with chloroform, or benzol, or ether, or carbon di- sulphide. The separation is by no means complete by one appli- cation of the solvent, and the more concentrated the aqueous solution the better. The chloroform or ether is caused to evapo- rate from the benzoic acid spontaneously or by a current of air from a bellows. Ether does not give as dry a residue as chloro- form. If the chloroform or ether or benzol solution be shaken with repeated portions of very dilute aqueous alkali, the benzoic acid is brought back into watery solution of benzoate. Also, ether, chloroform, etc., may be used upon dry materials, in sepa- rations of benzoic acid. (4) Precipitation, in a concentrated aqueous solution, by hydrochloric acid, collecting the precipitate after standing and at the coolest practicable temperature, is a convenient method of separation. The mother-liquid, or filtrate, may be shaken with chloroform to recover the acid remaining in aqueous solution. Materials such as benzoin resin may be di- gested with some excess of lime or alkali, and the filtrate of aqueous benzoate precipitated with acid, as in the manufacture of natural benzoic acid in the wet way. (5) The finely divided ma- terial may be heated, dry, for sublimation. In preparing the sublimed medicinal acid, the vapors are made to rise from a wide dish, through a porous paper diaphragm, and are collected upon the inner surface of a cone of sized paper, the edges being fitted or pasted close. The temperature of the sand-bath, or iron plate, should be kept some time at about 145 C. (293 F.), and gradu- ally raised at the close to 200 C. (392 F.), the operation requir- BENZOIC ACID. 65 ing from one to four hours. A second sublimate may be ob- tained after pulverizing the fused material and taking a fresh diaphragm. The Ph. Fran, directs the addition of an equal weight of sand to the powdered benzoin. An analytic sublima- tion, for separation from fixed impurities may be conducted in a pair of clamped watch-glasses with ground edges well fitted, or closed with a narrow ring cut out of thin asbestos cloth. (6) Precipitation with lead acetate, as indicated under J, serves the demands of separation from substances not forming insoluble lead compounds. (7) From cinnamic acid by precipitation of the latter, in a cold neutralized solution, with manganous sul- phate or chloride, avoiding any excess of this reagent. Manga- nous benzoate dissolves in about 20 parts of water ; manganous cinnamate is but slightly soluble in water. Ether or chloroform solution separates free benzoic from hippuric acid. (8) From milk, MEISSL (1882) adds lime to alkaline reaction, evaporates to one-fourth, adds gypsum, and dries on the water-bath. The dry mass, powdered, is extracted with alcohol, after acidulation with sulphuric acid. The alcoholic solution is neutralized with ba ryta, concentrated, acidulated with sulphuric acid, and extracted with ether, from which the benzoic acid crystallizes almost pure. f. Quantitative. Free benzoic acid, in absence of other acids, whether taken in distillates, or residues of separative sol- vents, or in original materials, can be quite closely estimated volumetrically with a standard solution of alkali (BOCKMAN : " Untersuchungsmethoden," 1884), using litmus as the indicator. The weighed material for estimation is treated directly with an excess of the volumetric alkali measured from the burette, stirred to bring all the benzoic acid into solution as benzoate, when the liquid is titrated back with the proper volumetric acid. Each c.c. of normal solution of alkali (after deducting c.c. of normal solution of acid) =0.122 gram of benzoic acid. Taking 1.22 gram of the material, each c.c. of decinormal solution of alkali (after deducting for the acid used in titrating back)i=l per cent, of benzoic acid. Benzoic acid may be weighed, directly, as C 7 H 6 O 2 . For this purpose the best form is that of good crystals, either from a so- lution or by slow sublimation. Tlie residue obtained by spon- taneous evaporation, of chloroform, ether, or other separative solvent of free benzoic acid also a clean precipitate may be weighed. The acid is to be dried over sulphuric acid, any excess of liquid or adhering moisture being first taken up with blotting- paper. 66 BENZOIC ACID. Salts of benzole acid are usually treated to obtain the free acid, as above described (e\ but they may be precipitated, in a neutral solution, by lead acetate, as stated under d. The lead benzoate, Pb(C 7 H 5 O Q ) 2 , is washed with cold alcohol acidulated with one- half per cent, of acetic acid, and dried at 100 C. The weight multiplied by 0.5416 gives the quantity of benzoic acid. g^ Impurities. Chemically pure benzoic acid is precisely the same in all properties, whether manufactured from the bal- samic benzoin or from urine, toluol, or naphthalene ; but a chemically pure acid has not been manufactured, on a commer- cial scale, from any source. The chief uses of benzoic acid are (1) in medicine and (2) in the production of dyes. It is used, also, for the manufacture of food flavors and as an antiseptic. For medicinal purposes the pharmacopoeias designate its source as follows : Ph. Germ. " From benzoin by sublimation . . . yellowish to yellowish-brown . . . with odor of benzoin, somewhat empy- reumatic." Br. Ph. " From benzoin ... by sublimation. Not chemi- cally pure. Nearly colorless." Ph. Fran. " From benzoin " prepared by alternative direc- tions (1) by sublimation, (2) by humid method. U. S. Ph. White scales or needles, " having a slight aroma- tic odor of benzoin." There may be two reasons for requiring medicinal benzoic acid to be sublimed from " the gum " : (1) the essential oil of benzoin obtained with the sublimed acid has a stimulant effect and an agreeable odor ; (2) by outlawing the artificial product the injurious impurities frequently present in it may be avoided. The artificial acid, quoted as " German benzoic acid," has been for several years priced at from one-third to two-thirds the value of the natural acid, quoted as "English benzoic acid." Un- doubtedly chemically pure benzoic acid will be made from hip- puric acid or from toluol (DYMOND, 1883 ; JACOBSEN, 1881), and furnished at prices lower than those for the natural acid. But hitherto, in any production of the artificial acid for medicinal uses, with little encouragement for open statement, there has been more effort to counterfeit the chemical impurities of the natural sublimed acid than to avoid the chemical impurities of the arti- ficial product. A chemically pure benzoic acid, from any source, is acceptable for the preparation of medicinal benzoates. In sensible properties the acid recently sublimed from ben- BEN ZOIC ACID. 67 zoin has a' white or pearl color if sublimed slowly, at tempera- ture of about 125-140 C., with rejection of the last fraction of sublimate, even this, from some varieties of benzoin, being nearly colorless. But a sharp heat, of about 200 C., gives a yellowish sublimate, becoming yellowish-brown in its last por- tions, and in proportion to increase of color is the distinctness of einpyreumatic odor obtained, in addition to the proper ethereal and vanilla-like odor of the benzoin obtained with colorless sub- limates. The acid sublimed from Sumatra or Penang benzoin has only a faint odor, not vanilla-like. Any einpyreumatic oil pervading the crystals darkens gradually by action of air, and colorless samples of sublimed benzoic acid are liable to acquire a yellowish tint on long keeping. Benzoic acid well prepared in -the wet way (p. 60) is in water-white crystals, larger and not so much in flocculent masses as the " flowers of benzoin." It has but a slight ethereal odor of benzoin, without empyreuma. But if it has not been crystallized from the precipitate it will contain much resin of benzoin, with some color, and will not dissolve clear in hot water. Artificial benzoic acid is frequently obtained in distinct prismatic crystals of considerable size. That from hippuric acid is apt to have a horse-stable odor ; that from to- luol, an odor of bitter-almond oil ; and imitated " flowers of benzoin " may have ethereal or empyreumatic odors. Cinnamic acid is occasionally present in all varieties of ben- zoin. In sublimation it requires a higher heat than benzoic acid, and its vapors are denser. Sublimed benzoic acid with einpyreu- matic odor and yellowish-brown color is likely to contain cinna- mic acid, if it were present in the benzoin. Benzoic acid from benzoin by the wet way is by no means likely to be free from cinnamic acid, if this were present in the benzoin. The impurities incidental to sources may be enumerated as follows : In natural benzoic acid by sublimation : Ethereal oil containing more or less styrol (cinnamene, C 8 H 8 ), vanillin (C 8 H 8 O 3 ) if prepared from the true Siamese benzoin (JANNASCH and RUMP, 1878), and sometimes empyreumatic distillate. Also cinnamic acid. In natural benzoic acid by the wet way : Cin- namic acid, resins, calcium chloride, ethereal oil. In the product from hippuric acid : Ammonia or nitrogenous bodies readily yielding it, substances giving the odor of urine or of the perspi- ration of the horse, hydrocyanic acid (a product of hippuric acid by heat), and chlorides. In toluol-benzoic acid : Chloro- toluenes, oil of bitter almond (benzoic aldehyde) which is formed from dichloro-toluene, while benzoic acid results from trichloro- toluene ammonium compounds, chlorides and sulphates. 68 BEN ZOIC ACID. Imitated natural benzole acid is prepared bj subliming from a mixture of (odorless) artificial benzoic acid, and either benzoin or the resinous residue after sublimation of the natural acid. Also, by addition of ethereal oils, etc. Tests. For cinnamic acid, by its oxidation, giving benzoic aldehyde, with odor of bitter-almond oil. One gram of the acid (itself free from almond odor) with half as much permanganate of potassium, rubbed in a mortar with a few drops of water (U. S. Ph.) A mixture of the acid* with equal quantity of the permanganate and ten parts of water is warmed for a short time in a test-tube (Ph. Germ.) The test is delicate and sufficient, but the decoloration of a permanganate solution has no meaning in the quest for cinnamic acid. For the ethereal and e-mpyreu- matic oils peculiar to natural benzoic acid by sublimation (chemi- cal impurities in evidence of medicinal genuineness), their reac- tions as reducing agents upon permanganate, or upon silver in alkaline solution, are resorted to, as follows : Of the saturated water solution, when cold, 10 c.c. are treated with about 10 drops of solution of potassium permanganate (1 to 1000). With the true sublimed acid the color changes to red-brown and brown in from 1 to 2 minutes ; with natural benzoic acid by precipitation and crystallization the color changes in 4 to 8 minutes ; with various samples of artificial acid treated to imitate the natural sublimate, over 2 minutes (Hagers Commentar, 2d ed., 59). 1 IBoil 0.1 gram of the acid with 3 c.c. of water of ammonia ; add about 5 drops of silver nitrate solution, and then drops of diluted hydrochloric acid until a permanent and decided turbidity is just reached (while there is still a very slight excess of ammonia). "With true sublimed benzoic acid the slight precipitate is not white, but yellowish. Concentrated sulphuric acid, with a smaller quantity of the benzoic acid, gives a yellowish color with the sublimed acid, becoming brown at 150 C. ; while at this high temperature the chemically pure acid remains colorless, and traces of hippuric acid give a brown to black color. For am monium or other nitrogenous compounds accompanying an acid made from the urine, dissolve in a wide test-tube with a little alcohol and fixed alkali to strong alkaline reaction, heating to near boiling, and testing the vapor with moistened red litnius-pa- per and by the odor, for ammonia. For chlorides and sulphates, 1 Hager severely criticises the Ph. Germ, direction to give 8 hours for this reaction. Upon this and other tests of genuineness of natural benzoic acid, see LENKEN, 1882; SCHAER, 1882; SCHNEIDER, 1882; SCHICKUM, 1882; SCHACHT, 1881; JACOBSEX, 1881 ; DYMO:,*D, 1883. CINNAMIC ACID. 69 test the saturated aqueous solution with silver nitrate solution, and barium chloride solution. For chloro-toluenes, slowly heat a portion under solid potassium or sodium hydrate (free from chloride) on platinum foil, dissolve the mass in water, filter if necessary, acidulate with nitric acid, and test with silver nitrate solution. Or apply the blow-pipe test for chlorine, with the copper bead, as directed by the TJ. S. Ph. For hippuric acid, and gross organic and inorganic adulterations, heat a portion to vaporization and combustion, on platinum foil or clean porcelain. It should vaporize and burn, with only a residual stain : a coaly mass or incombustible residue indicating gross impurity. Also, apply any of the solvents of benzoic acid, chloroform, ether, benzol, or carbon disulphide. Hippuric acid is but slightly solu- ble in ether or chloroform. For hydrocyanic acid, distil a por- tion with a little water, and test the distillate for conversion into sulphocyanate. If a benzoate be tested, acidulate with sulphuric acid before distilling. The medicinal oenzoates (see c, p. 62) are especially liable to be found with the injurious impurities of artificial benzoic acid. They should be tested, as above indicated, for cyanides, chlorinated compounds, salts of hippuric acid, etc. CINNAMIC ACID. Zimmtssaure. Cinnamylsaure. Acide Cinnamique. C 9 H 8 O 2 =l-8 (monobasic). Phenyl-acrylic acid: CgII 5 .CII.CII.CO 2 H. Sources: As free acid or in combin- ation with ethereal bases, in various balsams and with resins. Balsam of Peru contains often 10 per cent, of the acid free, and a larger quantity as cinnamate of benzyl (C 7 H 7 ) ; tolu bal- sam, 10 or 12 per cent, of cinnamic acid, mostly free ; storax, a variable quantity of the acid, mostly in combination; and some varieties of benzoin contain it. It is found in large crystals in old oil of cinnamon, formed by atmospheric oxida- tion of cinnamic aldehyde, (C 6 H 5 . CH . CH . COH) the cinnamon oil itself. The leaden packages in which oil of cinnamon is im- ported sometimes furnish a deposit of lead cinnamate with free cinnamic acid. It is producible from benzoic aldehyde. Fur- ther, see g. Cinnamic acid is characterized by its crystalline form in a sublimate (a) and its precipitation as free acid (c). It is revealed, \yiien only in traces, by its oxidation to benzaldehyde (d), a dis- tinction from benzoic acid. Its metallic precipitates are not mark- edly characteristic, that with iron resembling benzoate (d}. It is separated by methods used for benzoic acid, and from the latter with some difficulty (e). Estimated gravimetrically as free acid 70 C INN A MIC ACID. (f). Its natural combinations, and sources of production, are described in g. a. Cinnamic acid is a colorless solid, crystallizing (from vapor or solution) in monoclinic prisms or plates. Specific gra- vity (at mean temperature, water at 4 C. as 1.) 1.247 (SCHROZDEK, 1879). It melts at 133 C. (271.4 F.) (MILLER, 1877 ; TIEMANN and HERZFELD, 1877). It boils at 300 to 304 C. (572-579 F.) (E. KOPP, 1849), suffering partial decomposition unless heated gradually, the products containing cinnamene (C 8 Hg), stilbene, carbon dioxide, etc. It vaporizes much below its boiling point. J. Without odor, and of an aromatic, slightly sharp taste. The vapors are pungent and excite coughing. In doses of 5 to 6 grams (80 to 90 grains) it causes a just perceptible irritation of the throat. After its administration the urine contains cinnamic acid with hippuric acid, the latter probably preceded by oxida- tion to benzoic acid (ERDMANN and MARCH AND, 1842). c. Yery sparingly soluble in cold water, moderately soluble in boiling water, freely soluble in alcohol, soluble in ether. With litmus and other indicators it shows an acid reaction. The me- tallic cinnamates are monobasic, stable salts. Those of the alkali metals are soluble in water ; of alkaline-earth metals more soluble in hot water ; most others little soluble in water. Aqueous solu- tions of alkali cinnamates, on adding an acid, give a precipitate of cinnamic acid. By dry distillation they yield, among other pro- ducts, benzaldehyde. Ethyl cinnamate boils at 266 C., is of specific gravity 1.3, nearly insoluble in water, soluble in alcohol and in ether. Methyl cinnamate has a specific gravity of 1.106, boils at 241 C., and is insoluble in water. KRAUT and MERLINO (1881) mention a compound of cinnamic acid with hydrochloric acid. d. Oxidized with permanganate of potassium, or with dichromate of potassium and sulphuric acid, cinnamic acid yields benzaldehyde, or bitter-almond oil, recognized by its odor. The solid material may be treated with half as much solid perman- ganate, rubbing with a little water in a mortar. Or the solu- tion may be charged with permanganate solution, and warmed. C 6 H 5 . CH . CH . COJI+40 = C 6 H 3 . COH + 2CO 2 + H 2 O. The oxidation may continue to the conversion of the benzaldehyde into benzoic acid. Ferric salts with solutions of cinnamates give a yellow precipitate of ferric cinnamate ; manganous salts with excess of cinnamates, a white precipitate (none with ben- zoates) ; lead acetate, a precipitate of lead cinnamate ; and silver BERBER! NE. 71 nitrate, a stable white precipitate of normal silver cinnamate. The barium and calcium precipitates dissolve in hot water. e. Aqueous solutions of free cinnamic acid can be concen- trated, and the residue can be dried on the water-bath, without loss of more than traces of the acid. Sublimation cannot be em- ployed, under ordinary conditions, without waste by decomposi- tion. Precipitation of cinnamic acid, in cold and not dilute solutions of cinnamates, by adding hydrochloric acid, serves well for separation. The free acid may be dissolved from aqueous or dry mixtures by repeated ' portions of ether. Benzoic and salicylic acids are liable, if present, to appear in separates with cinnamic acid. Among solid sublimable acids may be further named succinic and gallic acids, but these are soluble in water. As to separation of cinnamic from benzoic acid, see the latter (e, 7, etc.) f. Cinnamic acid may be weighed, as C 9 H 8 O.,. For this purpose it may be prepared in crystals from alcohol or hot water, or in residue from ether, or in precipitate from cold concentrated solution. g. The appearance of cinnamic acid in analysis raises the question of its production, or liberation, by the operations of the analysis, from an ethereal salt of cinnamic acid, or from its alde- hyde, or alcohol. Cinnamein, benzyl cinnamate, making a large part of Peru balsam and a small part of tolu balsam, is liquid at ordinary temperature, neutral in reaction, of sp. gr. 1.098 at 14 C., boiling with some decomposition at 340-350 C., not soluble in water, soluble in alcohol, ether, or carbon disulphide. Styracin, cinnamyl cinnamate, is found in storax, crystallizing in needles or four-sided prisms, of sp. gr. 1.085 at 16 C., melting at 38 to 44 C., and distilling with steam at 180 C. without de- composition. It is insoluble in water, soluble in hot alcohol and in ether. Both cinnamein and styracin are easily saponified by digestion with fixed alkali or alkali carbonate, when the aqueous solution, by acidulation with hydrochloric acid, yields cinnamic acid. The styrone of storax and Peru balsam is cin namic alcohol (C 6 H 5 . CH . CH . COH 3 ) ; and the cinnamene or styrol, of storax, is the related hydrocarbon, C 6 H 5 . CH . CH 2 . The union of benzoic acid with cinnamic acid, (C 7 H 6 O 2 ) 2 C 9 H 8 O 2 , melts at 95 C. BENZOYL-ECGONINE. See COCA ALKALOIDS. BERBERINE. C 20 H 17 NO 4 = 335. The yellow alkaloid of 72 BERBERINE. Hydrastis canadensis, species of Berberis and Coptis, and other plants. As a hydrochloride, often commercially named hy- drastine. 1 Found as follows : In Hydrastis canadensis, Ranunculaceae, 1.3 to 1.8 per cent. (LLOYD). " Coptis trifoliata, 4$ (Perrins). u " teeta (India), 8.5$ (PERKINS). " Xanthoriza apifolia. " Berberis vulgaris, Berberidacese, 12$ (Perrins). " aquifolinm. " " aristata. " Jeffersonia diphylla. " Caulopliylum tlialictroides (Husem ami's Pfl.) " Jateorrhiza calumba (calumba root), Menispermacese. " Minispermnm canadense. " Coscinium feiiestratum (Ceylon calumba wood). " Coelocline polycarpa, Anonacese. " Xanthoxylum clava Herculis, Rutacese. In several of these sources berberine is accompanied with a colorless alkaloid. Its chemical relation to hydrastine is men- tioned in the description of the latter. Berberine responds to the general tests for alkaloids (<#), among which it is at once distinguished by its color and by the crystalline precipitations of its hydrochloride and nitrate (d). These precipitations, as well as its abundant solubility as a free alkaloid in hot water, serve to separate it from other alkaloids. Its separation from its vegetable sources is outlined, with refe- rences, under e. It is estimated as free alkaloid or crystalline salt, gravimetrically ; by Mayer's solution, volumetrically. a. In brown-red pencils, grouped in irregularly radiate clus- ters ; also in branched, curved, and pointed prolongations ; some- times appearing orange-red to yellow. In amorphous and ob- 1 As first found in different plants, this alkaloid was named as follows: In Geffraya inermis, bark, by Hut tense hm id, in 1824, as je.^ " Xanthoxylum clava H., by Clievallier and P., in 1820, as xanthopicrite. " Hydrastis canadensis, by Bafinesque, in 1828, as hydrastine. " Berberis vulgaris, by Buchner and H., in 18oO, as berberine. "We . . . think it unfortunate that, since the name Hydrastis was ac- cepted by botanists, it was not followed by chemists in the naming of its pro- minent constituent, the yellow alkaloid ": J. U. and C. G. LLOYD, in " Drugs and Medicines of North America," 1884, p. 98. An early paper on this alkaloid was that of J. D. PERRINS, 1862: Jour. Chem. 8oc., 15, 839. BERBERINE. 73 scurely crystalline forms it is yellow. At 120 C. it melts to a red-brown resinous mass. As crystallized from water, it loses 19.26$ water at about 100 C. (FLEITMANN), indicating about 5H 2 O of crystal-water in air-dry crystals. The hydrochloride, Co II 17 NO 4 HCl . 2H 2 O, forms large, lustrous, golden-yellow crys- tals, in pencils, with ends both square and oblique, slightly grouped. The hydrobromide, normal with 1II 2 O, forms bright yellow, fine needles. The hydriodide, normal, forms reddish- yellow needles. The nitrate is a normal salt, in clear yellow needles. Berberine sulphate, (C 20 H 17 NO 4 ) 2 H 2 SO 4 , crystallizes in irregular oblong plates of garnet-red color, or in stellate spangles of lemon-yellow to orange-yellow color. Berberine acid phosphate, C 20 H 17 NO 4 (H 3 PO 4 ) 7 , 1 is a canary-yellow powder. J. Berberine and its salts are inodorous and of a bitter taste. It is given, medicinally, in doses of 2 to 5 grains ; 60 grains having been taken without injury. Small animals are poisoned by it; 1 gram subcutaneously causing the death of dogs in 8 to 40 hours. c. The free alkaloid is soluble in about 500 parts of cold water, freely soluble in boiling water; sparingly soluble in cold, freely soluble in hot, alcohol ; insoluble in ether or in petroleum benzin ; slightly soluble in chloroform or in benzene. Its solu- tions have a neutral reaction. In salts or from acidulated solu- tions it is imperfectly taken up by benzene, chloroform, or amyl alcohol, not by petroleum benzin. It is permanent in the air and in solutions. The solubilities of salts of berberine are in- dicated under d. d. The caustic alkalies color berberine brown, with forma- tion of a resinous mass on boiling. On acidulating an aqueous solution of berberine with hydrochloric or nitric acid the salt of the alkaloid quickly crystallizes in bright-colored crystals, mostly golden yellow, thrown out of solution more perfectly by adding a considerable excess of tho acid. The hydrochlorate is soluble in about 500 parts of water or 250 parts of alcohol (from data of LLOYD) ; the nitrate is very slightly soluble in dilute nitric acid (PERKINS) ; the normal sulphate, in 10 parts of water or 293 parts of alcohol (LLOYD) ; the super acid phos- phate, in 10 parts of water. The general reagents for alkaloids give precipitates of ber- berine, mostly yellow the phosphomolybdate turning blue on 1 PARSONS and WRAMPELMEIER, 1877; COBLENTZ, 1884. 74 BERBERINE. adding ammonia. The red-brown precipitate by iodine in po- tassium iodide solution, when crystallized from hot alcohol, ap- pears in green, iridescent scales. Concentrated sulphuric acid gives a brown to orange color ; turning black to violet by add- ing dichromate, as in the fading-purple test for strychnine. Froehde's reagent gives a green to brown color. Chlorine water added to an aqueous acidulous solution of the hydro- chloride gives a band of bright-red color at the point of contact, visible as a rose tint in a dilution to 250000 parts (KLUGE, 1875). By distillation with milk of lime, or with lead dioxide, quinoline is obtained. e. Berberine is separated from Hydrastis canadensis (or other plant containing it), according to PERKINS (1862), by treat- ing with boiling water to prepare a concentrated extract, extract- ing this with alcohol, adding a little water and distilling off the alcohol, then adding dilute nitric acid (Perrins) or hydrochloric acid in some excess, and leaving several days for the crystalliza- tion of the salt. To obtain the free berberine, add calcium hy- drate or barium carbonate, extract witli hot alcohol, and, after evaporating off the alcohol, crystallize from a hot watery solu- tion, drying the crystals at a temperature not above 25 C. For the preparation of the various salts of berberine, as well as its recovery from the vegetable drugs containing it, see Lloyd's " Drugs of North America," I, 98. From most alkaloids berberine is separated (1) by its greater solubility as free alkaloid in hot water; (2) by its much smaller solubility as hydrochloride in dilute hydrochloric acid. As to se- parations by the solvents immiscible with water, see (c), p. 73. f Quantitative. Berberine may be weighed as free alka- loid, anhydrous, by drying at 100-110 C. - The nitrate, normal, anhydrous, may be dried at 100 C. for weighing (PERKINS). The precipitate by potassium mercuric iodide, washed and dried at 100 C., contains very nearly 50 per cent, of anhy- drous berberine (BEACH, and the author, 1876), corresponding nearly to the composition (C 20 H 17 NO 4 ) 2 (HI) 2 HgI 2 (48.55^). In the volumetric method by Mayer's solution Beach found the val- ue of a c.c. of the solution to be 0.0425 gram of the anhydrous alkaloid. In results reported by the author in 1880 ' the washed iodomercurate was found to contain a mean of 52 10# of the al- kaloid. Perrins weighed the washed and dried precipitate of platinic chloride (C 20 H 17 NO 4 ) 2 (HCl) 2 PtCl 4 . ^'Estimation of Alkaloids by Potassium Mercuric Iodide," Am. Chem. Jour., 2, 303. BUTYRIC ACID. 75 BRUCINE. See STRYCHNOS ALKALOIDS. BUTTER. See FATS and OILS. BUTYRIC ACID. C 4 H 8 O = 88 (monobasic). Normal bu- tyric acid, or prop yl-carboxyl, CII 3 CII 2 CH 2 .COoH.' The bu- tyric acid of glycerides of milk fat, and of the butyrous fermen- tation, following the lactous fermentation, of sugar. Found among the fat acids of cod-liver oil. Normal butyric acid is characterized by its odor when free and by the very different odor 'of its ethyl ester (d). It is sepa- rated by distillation, by solution in ether, and by the solubility of its calcium salt in alcohol (e). It is estimated by the acidi- metry of the free acid (f). Further, see under Butter Fats, Index. a. Normal butyric acid is a colorless, limpid liquid, solidify- ing in tabular forms at 19 C., having a specific gravity of 0.958 atUC., boiling at 162.3 C., distilling completely by itself, better with water, and vaporizing at common temperature. Its oil-spot on paper is not permanent. The buty rates are crystallizable, in tabular or needle-shaped forms, usually with fat-lustrous surfaces. When quickly heated they carbonize abundantly ; when slowly heated they evolve rancid-smelling vapors and carbonize slightly. b. The odor of pure normal butyric acid somewhat resem- bles rancid butter, but is less disagreeable and more pungent, approaching to the acetous odor. The taste is acidulous and biting, and unless diluted it is somewhat caustic to the tongue and irritating to the skin. Its glyceride, conjugated with gly- cerides of non volatile fat acids, is a food constituent especially provided for the young in the order of nature. Ethyl butyrate lias a fragrant odor of the pineapple, in which it is found. c. Solubilities. Normal butyric acid is freely soluble in water, though but little soluble in aqueous solutions of sodium chloride and various other salts. It is freely soluble in alcohol and in ether. The solutions redden litmus, and decolor alkaline phenol- phthalein solution. The metallic butyrates, for the most part, save those of silver and lead, are soluble in water, and some 1 There are two butyric acids, as four-carbon members of the fatty acid series, CnH 2 n0 2 . The other one is Isobutyric acid (CH 3 ) 2 CH.C0 2 H. or di- methyl acetic acid. Isobutyric acid is found among the fat acids of castor oil. 76 BUTYRIC ACID. of them dissolve in alcohol. Alkali butyrates are neutral to litmus. Ethyl butyrate is sparingly soluble in water, soluble in alcohol in all proportions. d. Normal butyric acid is identified by its pungent, rancid odor when free (b), and the pineapple odor of its ethyl ester, while its glyceride and its' alkali salts are nearly odorless. Warming butyric acid or a metallic butyrate with a little alco- hol and about twice as much undiluted sulphuric acid, the ethyl butyrate is readily formed, and odor obtained. If the butyric acid is free, in dilute solution, it should be neutralized with alkali and the solution concentrated for the test. Ethyl butyrate is stable, not readily saponified. Glyceride of butyric acid, butyrin, should be saponified by alcoholic potash before applying the test. Calcium or barium chloride does not precipitate mode- rately dilute solutions of butyric acid or its salts. Silver nitrate gives a precipitate in moderately concentrated solutions. Lead acetate and subacetate, in moderately concentrated solutions, give precipitates which dissolve in alcohol or hot water, and m'elt on heating. Ferric chloride, in solutions of butyrates, gives a brownish-yellow precipitate, as formed in dilute solutions much resembling the benzoate, and not formed by free butyric acid except in concentrated solutions. e. Separation. Normal butyric acid, in alkali salt solutions, can be concentrated on the water-bath without loss. By treating metallic butyrates with phosphoric acid or dilute sulphuric acid, and distilling persistently, all the butyric acid can be obtained. Butyric acid is separated from acetic and other homologous acids by the greater solubility of barium butyrate in alcohol : The free acids are saturated with barium hydrate solution, the mixture concentrated enough to stiffen when cold, then treated with about ten parts of strong alcohol, set aside one or two hours, and filtered, washing with alcohol. The residue will contain the most of the acetate, while the butyrate will mainly be in the solution. Of absolute alcohol, 1000 parts dissolve 11.72 parts of barium butyrate, 0.28 parts of barium acetate, 0.05 parts barium formate, and 2.61 parts of barium propionate (LUCKE, 1872). Butyric acid may be recovered from aqueous mixtures, as a free acid, by saturating with sodium chloride or with calcium chloride, and shaking with ether. From the ethereal solution it is recovered, as alkali salt, by shaking with a slight excess of fixed alkali solution, or as free butyric acid, with only slight waste, by the spontaneous evaporation of the ether. CAFFEINE. 77 f. Quantitative. Butyric acid is estimated with ease, volu- metrically, by standard solutions of alkali, fixing the neutral point either with litmus-papers or, more exactly, with phenol- phthalein. Each c.c. of normal alkali saturates 0.088 gram, and each c.c. of decinormal alkali saturates 0.0088 gram, of absolute butyric acid. Of a mixture containing no other ac^id, if 4,-i grams be taken, c.c. of N alkali X 2 per cent, of free butyric acid, or c.c. of yV alkali X 20 = per cent, of free butyric acid. CAFFEINE. Theine. Guaranine. Coffein or Koifein. Cafeine (French). Methyl-theobromine. C 8 H 1Q ]Sr 4 O 2 =194:. ' (Crystallizes with 1 aq. ; also, anhydrous.) A trimethyl xan- thine : C 5 H(CH 3 ) 3 N 4 O 2 ; a xanthine being producible from gua- nine, or uric acid. In Tea (prepared leaf of Camellia Thea), 2 to 3 per cent. " Coffee (dried seed of Coffea arabica), 1 per cent. " Guarana (cm shed seed of Paulinia sorbilis), 4 per cent. " Mate (leaf of Ilex paraguayensis), 1J per cent. " Cola nut (seed of Sterculia acuminata), 2 per cent. These percentages are given to represent average yields. 3 Caiteine is producible from theobromine and from xanthine (STRECKER, FISCHER) Caffeine is identified by the murexoin test (d), and the form in which it crystallizes under the microscope (a). It shares its most distinctive tests with Theobromine, from which it differs iatly in solubilities. It is distinguished from most other alka- " by non-precipitation with potassium mercuric iodide, by yield- ing cyanide when smelted with soda-lime (^7), and by dissolving in water, and from acidulous mixture dissolving in chloroform, etc. (c and e). It is separated as stated under , and estimated in tea, coffee, guarana, etc., by its weight, as obtained (1) by extract- ing with water and dissolving the residue in ether, (2) by ex- tracting with water (and alcohol) and shaking out with chloro- form, (3) by extracting witli chloroform and dissolving the residue in water, (4) by sublimation (/). Tests for impuri- ties, g. 1 PFAFP and LIEBIG, 1832: Ann. Chem. Phar., i, 17. 2 STRECKER, 1861 : Ann Chem. Phar., 118, 72, 151. E. FISCHER, 1882 : Ann. Chem,. Phar., 215, 253-320: Jour. Chem. Soc., 1883, Abs , 354. E. SCHMIDT. 1883. 3 For tea and coffee and guarana, DRAGENDORFF, 1874 : " Werthbestim- mung." 56 . SQUIBB, 1884 : Ephemeris, 606, 614. 616. For Paraguay tea. BY- ASSON, 1878. For Cola nut, HECKEL and SCHLAGDENHAUFFEX, 1884 : Phar. Jour. Trans., Am. Jour. Phar. Also, ATTFIELD, 1865. E. SCHMIDT And report of J. F. GEISLER in article " TEAS '' in this work. 78 CAFFEINE. a. Caffeine appears in long, slender, flexible white crystals, of silky lustre, forming light, fleecy masses. The crystals have a specific gravity of 1.23 at 19 C. They are permanent in the air. On the spontaneous evaporation of a drop or two of an aqueous or chloroformic solution, dilute enough to crystallize slowly, on a glass slide, characteristic crystals are identified by a magnifying power of 100 to 300 diameters. The forms are chiefly acicular; finely pointed needles of some thickness at their overlapping basal ends making irregularly stellate groups, with a few separate needles. Among these, of later appearance and requiring the higher power above named, are the more characteristic forms, namely : six-sided crystals, dihexagonal pyramids and prisms, with a few rhombohedrons. From the chloroformic solution the stellate groups are found each with a single hexagonal crystal in its centre. Anhydrous crystals are said to be obtained from ether or absolute alcohol. DKAGENDOKFF 1 directs to dry at 100 C. for a constant weight of anhydrous alkaloid ; COMMAILE (1875) gives the same direction. BLYTH (1878) states that at 79J C. minute microscopic crystals in sublimate can be obtained, and a com- plete sublimation in long, silky crystals readily obtained near 120 C. ; also that the high subliming points given by Pelouze and Mulder must have been given from faulty methods. When anhydrous, caffeine melts at 234 C. (STKECKER, 1861), and the melted mass boils at 384 C. with partial decomposition, leaving no residuum. b. Caffeine is without odor and with a bitter taste. The maximum medicinal dose is about 3 grains : Br. Phar. dose 1 to 5 grains ; Ph. Germ, maximum single dose 3 grains.* c. Caffeine is sparingly soluble in cold water; freely soluble in hot water and in chloroform ; moderately soluble in alcohol and in benzene ; slightly soluble in ether ; nearly insoluble in petroleum benzin or carbon disulphide. Combination with acids scarcely hinders its solubility in chloroform or benzene. More particularly, the hydrated crystals dissolve in 68 parts of water at 15 to 17 C. (CoMMAiLE 3 ) ; in 75 parts water at 15 C. (U. S. Ph.) ; in 80 parts cold water (Ph. Germ., Br. Ph.) ; in 9.5 parts of boiling water (U. S. Ph.) ; 10 parts boiling water (Hager's 1 " Werthbestimmung," 1874, p. 57. 2 For physiological assays of tea, coffee, and guarana, in comparison with caffeine, SQUIBB, 1884 : Ephemeris, 2, 603, 610, 615, 617. 3 1875: Compt. rend., 81, 817; Jour. Chem. Soc., 1876, i. 779. CAFFEINE. 79 Commentar) ; 2.01 parts water at 65 C. (COMMAILE) /^Jo^lcohol of about 90 per cent., 35 parts at 15 C. (U. S. Ph.), 50 parts (Ph. Germ.), 40 parts at 15 to 17 (COMMAILE) ; in absolute al- cohol it is less soluble, in 155 parts (Ilager's Commentar). In ordinary ether it dissolves in 476 parts at 15 to 17 C. (COM- MAILE), 600 parts (HAGER). The anhydrous alkaloid dissolves in 75 parts water at 15 to 17 C (COMMAILE) ; in 165 parts absolute alcohol at 15 to 17 C. (COMMAILE) ; in 32 parts boiling absolute alcohol (COMMAILE); in 8 parts chloroform at 15 to 17 C., or 5J parts boiling chloroform (CPMMAILE) ; in 2288 parts of anhy- drous ether at 15 to 17 C. (COMMAILE); in 4000 parts of petroleum benzin at 15 to 17 C. (COMMAILE). Caffeine is neutral to test-papers, notwithstanding its solu- bility in water. It is a very feeble base. Salts of caffeine are formed only by action of concentrated acids upon the alkaloid ; they are all decomposed by water, alcohol, and ether, and those of volatile acids are decomposed by exposure to the air (E. SCHMIDT). 1 Many of the salts crystallize in needles, the hydro- chloride, C 8 H 10 N 4 O 2 . HC1, in monoclinic forms. The caffeate crystallizes as C 8 H 10 N 4 O 2 .C 8 H 8 O 4 .2H 2 O. The sulphate has been obtained, from hot alcoholic solution, in crystals of the composition C 8 H 1(V N" 4 O 2 . H 2 SO 4 (SCHMIDT). The citrate was re- ported by LLOYD (1881) as "a possible definite salt, but so frail that it is decomposed by solvents which dissolve citric acid readily and caffeine sparingly : it is given by the Br. Ph. with the formula C 8 II 10 N 4 O 2 .H 3 C 6 II 5 O 7 (implying that caffeine is here a tri-acid base). The double salts of caffeine are less in- stable (see d, platinum, etc.) d. Caffeine responds promptly to "the murexid test" as follows : A portion of solid material or a residue by evaporating a liquid to be tested, not over a grain or two at most, is taken in a white porcelain evaporating-dish, heated on the water-bath, then covered with from one to five drops of hydrochloric acid, when at once a minute fragment of potassium chlorate is added, the mixture evaporated to dryness and well dried on the water-bath. When cold the residue is slightly moistened with ammonia water applied by the point of a glass rod. In evi- dence of caffeine a purple color (that of mwrexow) is obtained after the action of ammonia ; a reddish-yellow to pinkish color before the action of ammonia. 0.00005 gram of caffeine, in a residue small enough to be covered by one drop of hydrochloric acid, yields decisive evidence by this test. Fuming nitric acid, 1 1881: Ber. d. chem. Ges., 14, 814; Jour. Chem. Soc., 1881, Abs., 746. 8o CAFFEINE. or chlorine water, serves as the oxidizing agent, but less effi- ciently. The products of the oxidation include amalic acid and hydrocyanic acid. 1 By the action of ammonia the murexoin is formed. The amalic acid and murexoin are tetramethylated de- rivatives of the corresponding products obtained in the murexid test of uric acid, thus : By the oxidation By the action of ammonia, (with other products). Uric acid: Alloxantin, C 8 H 4 N 4 O 7 . Murexid, NH 4 .C 8 H 4 N 5 06. Caffeine: Amalic acid, C e (CH 3 ) 4 N 4 7 . Murexoin, NH 4 . C 8 (CH 3 ) 4 N 5 6 . The murexoin purple from caffeine is decolored and not turned blue, by adding potassium hydrate solution, a distinction from the murexid purple from uric acid. The amalic acid stains the skin red (also a characteristic of alloxantin). Tannic acid precipitates caffeine from aqueous solutions not very dilute, the precipitate being somewhat soluble in excess of the reagent. Phosphomolybdate of sodium gives a yellowish precipitate, soluble in warm sodium acetate solution, from which free caffeine separates on cooling (SONNENSCHEIN) Platinum chloride and hydrochloric acid with concentrated solution of caffeine gives an orange-colored precipitate, dissolving when heated, crystallizing on cooling (C 8 H 10 X 4 O 2 .HCl) 2 .PtCl 4 , solu- ble in 20 parts of water (STAHLSCHMIDT). Potassium bismuth iodide gives a precipitate on standing, soluble in 3000 parts water (THRESH, 1880). No precipitates are obtained with po- tassium mercuric iodide, or with iodine in potassium iodide solu- tion (distinction of caffeine, theobromine, and colchicine from nearly all other alkaloids). On heating caffeine with solid po- tassium hydrate, or boiling with strong solution of this reagent, methylamine is evolved and recognized by its strong, ammonia- like odor. Strongly heating a dry mixture of caffeine and soda- lime, ammonia is evolved, as with other alkaloids, while, in dis- tinction from most other alkaloids, a part of the nitrogen is re- tained in cyanogen, as alkali cyanide, revealed by treating the mass with water and testing a filtered portion for cyanides. e. Separations. Caffeine can be separated from the greater number of alkaloids by its greater solubility in water, and by its being dissolved from acidulous mixtures by chloroform, ben- zene, and (sparingly) by ether. From non-volatile matters it is separable by careful sublimation from a well-dried, finely pow- dered mass, at 100 to 150 C. (BLYTH). Separations from tea, coffee, guarana, etc., are presented under f. 1 ROCHLEDER, 1849: Ann. Chem. Phar., 71, 1. SCHWARZENBACH, 1859. CAFFEINE. 8 1 y*. Quantitative. The quantity of caffeine is determined gravhnetrically by weighing the alkaloid. According to BLYTH (1878) dry caffeine begins to sublime at 79.5 C. (175 F.), but the same author states ' that, so far as decided by his experiments, loss of the alkaloid does not occur at 100 C. until the material L quite dry, and there is no testimony to show that loss occurs from concentrating limpid aqueous solutions on the water-bath. At all events this has been done in many assay methods. And in nearly all methods except Blyth's it is directed to dry residues or crystals of caffeine at 100 C. for weight, an exposure to which the author just named demurs. For estimation of the caffeine in tea, coffee, guarana, mate, or cola several processes are serviceable, as follows : a 1. DRAGEN- DORFF'S process requires to exhaust 5 grams of the substance by maceration with boiling water, evaporating the filtrate with 2 grams magnesia and 5 grams of ground glass. 3 The pulverulent residue is transferred to a flask, macerated with 60 c.c. of ether for 24 hours, filtered, and the residue treated three or four times with the same quantity of ether. The ether is evaporated and the residue weighed. A smaller quantity of chloroform may be sub- stituted, but does not give as pure alkaloid. 2. Dr. SQUIBB (1884) takes 10 grams of powdered guarana and 2 grams of calcined magnesia, boiling with 100 c.c. of water for live minutes, adding while hot 50 c.c. of strong alcohol, draining on a filter, and percolating the residue with a mixture of 60 c.c. of water and 40 c.c. of alcohol. Boil the residue again with 100 c.c. of this mixture of alcohol and water, and drain and per- colate until exhausted, or until the total liquid amounts to 300 or 350 c.c. Evaporate this on a water-bath to about 20 c.c., and transfer to a separator, rinsing with a little water. Shake out with three or four portions each of 25 c.c. of chloroform. The chloroform solution is evaporated in a tared beaker for weight. The last chloroform washing may be evaporated in a separate 1 " Foods," 1882, p. 330. 2 DRAGENDORFF, 1874, 1882: " Werthbestimmung," 57: " Plant Analysis," London, 1884, 62, 186. SQUIBB. 1884: Ephemeria, 2 t 606, 614, 616. BLYTH, 1877, 1882: Analyst, 2, 39; "Foods. 1 ' 330. COMMAILE, 1875: Compt. rend., 81, 817; Jour. them. Svc.. 1876, i 779. 3 Those who depend upon the "extraction apparatus" for exhausting drugs in estimation may prefer to apply hot water to the drug by continuous percolation in this apparatus, heated by a sand-bath. Then the smaller quan- tity of solution can be evaporated in the receiver of the apparatus, after adding the magnesia and sand, by aid of a " filter-pump," at temperature not above 78 C. ; and the final residue by evaporation of the ether, dried below 80 C. -A. B. P. 82 CAFFEINE. tared capsule for indication of the completion of the extraction. The caffeine is white and nearly pure. Further purification is done by dissolving in least sufficient quantity of hot water and letting the filtrate spontaneously evaporate to dry ness. For tea the directions are nearly the same, except that a coarse powder is taken, no alcohol is used, and the larger, more dilute portion of the percolate is concentrated by itself. For coffee the method was the same as for tea (exhausting with water), except that when the percolate had been nearly evaporated 60 c.c. of alcohol were added, and the resulting precipitate filtered out and washed with a mixture of alcohol 3 and water 1, when the entire filtrate was evaporated to 20 c.c. This treatment is. adopted to prevent the gelatinizing of the albuminous matter by the chloroform. (3) COMMAILE directs to prepare 5 grams of the material with 1 gram of calcined magnesia in a firm paste, which is to stand 24 hours, and is then dried on the water bath [or in an air-bath be- low 80 C.] and powdered. It is then exhausted with boiling chloroform [applied in an extraction apparatus, from the receiver of which the chloroform is then distilled] and the residue dried [at a gentle heat]. 10 grams of powdered glass, previously washed with dilute hydrochloric acid, are then added, with hot water, which is then boiled, well shaken with the glass and poured on a wet filter. The residue is exhausted by washing with portions of hot water. The united filtrates are evaporated in a tared flask [exhausted by a pump, and dried at temperature not above 78 C.] (4) BLTTH proposes the sublimation of the caffeine from a paste of the aqueous extract mixed with magnesia, thinly spread on a thin iron plate, and covered with a tared glass funnel the heat very gentle at first and very gradually raised to about 200 C., until a fresh funnel will receive no crystals by continuation of the heat for half an hour. But the author prefers to sublime in vacuum, obtained by a mercury pump, the paste being spread on a ground glass plate, fitted with a ground flanged funnel, when very gentle heat by a sand-bath is sufficient. g. Tests for Impurities. Caffeine, gradually heated in a portion of about a grain in a test-tube over the flame, should completely sublime, leaving no residue, and yielding a subli- mate, usually melted nearest the heat and crystalline beyond. Contact with cold concentrated sulphuric acid should not cause coloration, and on heating at 100 C. should darken but slowly. ( Contact with cold (colorless) nitric acid should not give imme- CANTHARIDIN. 83 diate coloration. Caffeine should be colorless, should dissolve in 10 to 15 times its weight of boiling water, the solution remain- ing clear when diluted to 80 or 100 times its weight and cooled, and being neutral to test-papers. Respecting presence of theo- bromine, see under the latter. CAFFETANNIN. See TANNINS. CANTHARIDIN. C 10 H 12 O 4 =196. The highly poison- ous, vesicating principle of tjie Spanish Fly (Lytta vesicatoria\ which contains about 0.4$. It is also found in a great many other coleopterous insects. The powdered insects, after being moistened with acetic acid, are exhausted with chloroform or ether ; the extract evaporated to dryness ; the residue boiled with carbon disulphide (to remove fat), evaporated to dryness with a little caustic alkali, washed with chloroform, acidified, and agi- tated with chloroform, from which the cantharidin crystallizes on concentration. It may be purified by recrystallizing from alco- holic chloroform or from acetic ether. Cantharidin crystallizes in colorless prisms of the dimetric system or in laminae, which become soft at 210 C. and melt and sublime at 218 C. It sublimes, in part, at 180 C., but vola- tilizes at a much lower temperature together with the vapor of water, alcohol, etc. It is soluble in 5000 parts cold and 380 parts boiling water (more readily when just liberated by acids) ; in about 3500 parts cold and readily in hot alcohol ; in 910 parts ether; 84 parts chloroform; 500 parts benzene; 1666 parts carbon disulphide. It is soluble in volatile and fat oils ; very easily in aqueous alkalies. It is extracted from acid solutions by benzene, ether, chloroform, and amyl alcohol. Potassium hydrate solution extracts it completely from its solution in chlo- roform ; and by this means it is easily purified. Cantharidin acts as a weak acid, forming salts which are (especially the combina- tions with the fixed alkalies) easily soluble in water, and which possess the vesicating property. Solvents do not extract the cantharidin from these solutions, but it is precipitated by acids. Potassium cantharidate is crystallizable, very readily soluble in water, soluble in 3300 parts cold and 110 parts boiling alcohol, insoluble in ether and chloroform. In not too dilute solutions, the potassium and sodium salts give precipitates with barium and calcium chloride (white), copper sulphate (green), nickel sulphate (green), cobaltous sulphate (red), palladium chloride (yellow, hair-shaped, afterwards crystalline), lead acetate, and mercuric chloride. Undiluted sulphuric acid dissolves cantha- 84 CHELIDONINE. ridin without decomposing it. Concentrated sulphuric acid and potassium dichromate decompose it with separation of green chromium oxide. 0.0001 gram cantharidin is sufficient to draw a blister. For finding the per cent, of cantharidin in Spanish flies or preparations containing them, DRAGENDOKFF washes about 25 grams of the powder with petroleum ether till all the fat is re- moved (counting 0.0108 gram cantharidin for every 100 c.c. of solvent used), stirs the residue with 5 grains magnesia or soda, and water, evaporates to dryness on the water-bath, powders, adds 25 c.c. chloroform, acidifies with dilute hydrochloric acid, and agi- tates with 30 c.c. ether, repeating this last operation four times with same quantity of ether. He washes the ether solution seve- ral times with water, evaporates to dryness, transfers the residue (with help of a little alcohol) to a small tared filter, washes with alcohol, then with 2 to 3 c.c. water, dries at 100 C., and weighs, adding 0.007T gram for every 10 c.c. alcohol, and 0.0005 gram for every c.c. water used. According to this method he found 0.348$ in a sample of powdered cantharides [" Werthbest," 106]. CAPRIC, CAPROIC, AND CAPRYLIC ACIDS. See FATS AND OILS. CARBOLIC ACID. See PHENOL. CASTOR OIL. See FATS AND OILS. CATECHU-TANNIN. See TANNINS. CHELIDONINE. C 19 H 17 N 3 O 3 =335.--Found with san- guinarine in the herb, unripe seed- capsules, and root of the celandine (Chelidonium majus). The root contains the largest proportion. Crystallizes in colorless, glittering tablets, with two molecules water, which are driven off at 100 C. It melts to a colorless oil at 130 C. and volatilizes with steam ; is odorless and of a bitter, harsh taste; alkalfne in reaction, forming colorless, crystallizable salts which possess an acid reaction. The sulphate and phosphate are readily soluble in water. Chelidonine is insoluble in water, and, when crystallized, soluble in ether and alcohol only after continued boiling; more soluble in chloroform. Fat arid vola- tile oils dissolve it readily, benzene very slightly. Amy lie alco- hol extracts it most readiiy from solutions made alkaline. The alkaline hydrates precipitate the alkaloid in white flakes CITRIC ACID. 85 (becoming crystalline) from solutions of its salts. It gives a pre- cipitate with platinic chloride, not decomposed by water, con- taining 17.42 17.6# Ft. Potassio-mercuric iodide (MASING ') gives a precipitate C 19 II 18 ISr 3 O3l . HgI 2 . One c.c. MAYER'S solution precipitates 0.01075 gram chelidonine (DRAGENDORFF S ). Iodine in alcohol causes precipitation. Concentrated sulphuric acid dissolves it with bright colors, green at first, then brown, edged with red and violet, and, in presence of sugar, with rose- violet color, changing to cherry-red and blue-violet. Froehde's reagent gives a green color, changing to blue, brown, and black. Sulphuric acid and potassium nitrate give a green to blue color (KlJGELGEN, 1885). The alkaloid is obtained from the root by precipitating the acidulated (H 2 SO 4 ) water extract of the root witli ammonia, dis- solving out the sanguinarine by means of ether (the chelidonine is only very slightly soluble), then dissolving the residue in as little as possible acidulated (H 2 SO 4 ) water, and adding twice the volume of concentrated hydrochloric acid, which precipitates the hydrochlorate (soluble in 325 parts water). This is decomposed by dilute ammonia, and, after purification by redissolving in acidu- lated water and repeating the above process as often as may be necessary, is crystallized from boiling alcohol (WITTSTEIN). CITRIC ACID. H 3 C 6 H 5 O 7 =192. Citronensaure. Found in the greater number of the most acidulous fruits ; abundant in tomatoes, currants, gooseberries, raspberries, strawberries, blackberries, bilberries (GRAEGER, 1873), and tamarinds, and common in various parts of plants ; occurring for the most part as free acid, but also as acid salts. Manufactured from lemons and from limes, both which contain about 5 per cent., or 10 per cent, of the juice (STODDARD, 1868), and from sour oranges of Florida and bergamot oranges of southern Europe, no interfer- ing acids being present in these sources. 3 Cranberries contain over 2 per cent., with no other acid ; 4 unripe gooseberries, 1 per cent. ; and the red currant, about 1.3 per cent. 5 Used chiefly in 1 Jour. Chem. Soc., 1877, i. 477. 2 " Werthbestimmung," p. 102. 3 Warington (Jour. Chem. Soc., xxviii. 037) found in lemon-juice, lime- juice, and bergamot-juice formic and acetic, acids, and some non-volatile acid giving soluble calcium salt. 4 L. W. MOODY and the author : Am. Jour. Phar., 50 (1878), 566. 5 Hager's "Pharmaceutische Praxis," I., 52., with directions for manufac- ture. For lists of plants containing citric acid see Hager's "Untersuchungen," II. 109 ; Husemann's Pflanzenstoffe,' ? 555 ; Gmelin-Kraut's "Handbuch," v. 827. SILVESTRI, 1869: Jour, de Phar. et de Chim. [4], x. 305, reports 1 to 1} per cent, citric acid in Cyphomandra betacea, Mexico and South America. 86 CITRIC ACID. articles of food and medicine, but also to some extent to inten- sify certain colors and to remove mordants in dyeing. Citric acid is characterized by its crystallization (a) ; by its reactions with calcium and lead salts, its barium salt in well- marked crystals, and a color reaction with ammonia (d\ also by the limits of its reducing power (d). From Tartaric acid it is distinguished by its crystallization, its failure to give caramel odor when heated (Tartaric acid, a\ and its weaker reducing power with chromate, etc. (d), and is well separated by not pre- cipitating with potassium (Tartaric acid,/*). From ordinary fruit acids it is approximately separated, by treatment of lime salts, in the scheme given under Malic acid, e. Other separations are noted at e, p. 88. Estimation, by volumetric alkali, and from weight of barium precipitate (f, p. 88) ; in fruit juices, by direc- tions under Tartaric acid. Commercial forms and impurities are noted at g, p. 89. a. Citric acid crystallizes, from water solutions in the cold, as C 6 H 8 O 7 . H 2 O=r210, and this is the hy dratioit of the acid of commerce. 1 In very moist air the crystals deliquesce slightly ; at temperatures from 28 to 50 C. they effloresce, and then at 100 C. become anhydrous ; but exposed at once to heat of 100 C. the crystals melt. From boiling and saturated solution anhydrous crystals are obtained. The hydrated crystals are large, water-clear, right rhombic (trimetric) prisms. At about 175 C. citric acid decomposes, giving off pungent vapors, containing Acetone, while Aconitic acid (soluble in ether) is formed in the residue and then decomposed (C 6 H 8 O T =C 6 H 6 O 6 +H 2 O). b. Citric acid is soluble in its weight of water at com- mon temperature, and in half its weight of boiling water ; in about its own weight of ninety per cent, alcohol ; insoluble in absolute ether or chloroform, 3 and but slightly soluble in phar- macopoeial stronger ether or chloroform. Its water solution is inactive to the plane of polarized light. Standing in water solution it decomposes, and then gives misleading reactions of reduction. c. Citric acid, tribasic, forms normal salts, acid salts of one- third and two-thirds basal hydrogen, and basic double salts. The alkali metal salts are freely soluble in water; iron, zinc, and cop- 1 8.57 per cent, of water. Warington (Jour. Chem. Soc., xxviii. [1875], 927) found 8.72 per cent, as the mean of 17 representatives, with 8.46 per cent, and 9.35 per cent, as extreme ranges. 2 Soluble in 44 parts ether, at 15 C. BOURGOIN: Zeitsch. an. Cliemie, 17 (1878), 502, from Bull. Soc. Chim. Paris, 2p, 242. CITRIC ACID. 87 per normal citrates moderately soluble ; other non- alkali normal citrates mostly insoluble. Calcium citrate is somewhat soluble in cold, nearly insoluble in hot water. Citrate precipitates dis- solve in citric and other acids by formation of soluble acid citrates ; and dissolve in alkali hydrate solutions by forming basic double salts, such as the " soluble " citrate of iron and ammonium of pharmacy. Citric acid prevents the alkali preci- pitation of most heavy metals, the soluble double salts being formed. Indeed, numerous precipitations are prevented or hin- dered by presence of alkali citrates, 1 including most carbonates, phosphates (not ammonio magnesium), oxalates, sulphates, lead and barium chromates, ferric ferrocyanide, lead iodide and bro- mide, and arsenious sulphide. On the contrary, zinc and mag- nesium hydrates, lead sulphide, and most silver precipitates are not affected by citrates. Barium sulphate is precipitated in pre- sence of citrates only on boiling. Equal basal proportions of citrate and of the precipitates most favor their solution, which seems to be due to the formation of double salts. Alkali citrates are sparingly soluble in hot alcohol, less soluble in cold alcohol. d. Solution of lime, added to solution of citric acid to alka- line reaction or to citrates, causes no precipitate in the cold (dis- tinction from Tartaric, Racemic, Oxalic acids) ; but on boiling a slight precipitate is formed (distinction from Malic acid). Solu- tion of chloride of calcium does not precipitate solution of free citric acid even on boiling, nor citrates in the cold, but precipi- tates citrates (neutralized citric acid) when the mixture is boiled. The precipitate, Ca 3 (C 6 II 5 O 7 )o . 2H 2 O, is insoluble in cold solution of potassa (which should be not very dilute and nearly free from carbonate), but soluble in solution of cupric chloride (two means of distinction from Tartaric acid) ; also soluble in cold solution of chloride of ammonium and readily soluble in acetic acid. Solution of lead acetate precipitates from solutions of neutral citrates, and from even very dilute alcoholic solution of citric acid, the white citrate of lead, Pb 3 (C 6 H5O 7 ) 2 . iH 2 O, somewhat soluble in free citric acid, soluble in nitric acid, in solutions of all the alkaline citrates and of chloride and nitrate of ammonium, soluble in ammonia (formation of basic ammonium lead citrate). (Malate of lead is not soluble in malate of ammonium). The precipitation with barium is given in d. But if now the solution, with excess of barium acetate (and a little free acetic acid FRESENIUS), be heated about two hours on the water-bath, the 1 J. SPILLER: Jour. Chem. Soc., io ? 110; Phar. Jour. Trans., [3] 17, 282; Jahr. der Chemie, 1857, 569. 83 CITRIC ACID. barium citrate, as Ba 3 (C 6 H 5 O 7 ) 2 .3jHoO, crystallizes in clino- rliombic prisms (Kammerer 1 ). A color-test for citric acid is made by heating with ex- cess of ammonia- water as 5 grams of the acid to 30 c.c. am- monia-water in a sealed tube, at 120 C., for six hours. 3 On exposure to the air and light in an evaporating-dish the solution turns blue, slowly changing to green and becoming colorless. Usually small crystals form in the heated tube and afterward dis- appear. At 150 C. the solution turns green in the tube, but at 160 C. the reaction is not obtained. Tartaric, oxalic, and malic acids do not interfere. The least quantity of citric acid revealed by the test is 0.010 gram. Nitrate of silver precipitates from neutral solutions of ci- trates white normal citrate of silver, not blackened by boiling (distinction from Tartrate). Solution of permanganate of po- tassium is scarcely at all affected by free citric acid in the cold. With free alkali the solution turns green slowly in the cold, readily when boiled, without precipitation of brown binoxide of manganese till after a long time (distinction from Tartrate). Dichromate of potassium solution is not reduced by citric acid (distinction from Malic, etc.) e. Citric acid is separated from acids making soluble lead salts, through precipitation with lead acetate and subsequent treatment with hydrogen sulphide. From tannins and gallic acid, as noted under Gallotannin. Insoluble citrates are con- verted to alkali citrates, as noted under gravimetric estimation, below. f. The acidimetry of citric acid, with litmus as an indicator, can be accurately done only by standardizing the alkali solution with weighed pure crystallized citric acid, using the same litmus- paper and holding the same conditions both in standardizing and in the estimation. 3 Warington states that the litmus color " changes in a perfectly gradual manner," that " the amount of alkali used is a little less than that required by theory to form trisodic citrate," and " the more delicate the litmus-paper the nearer does the experiment approach " a neutral reaction for the normal salt. But with phenol-phthalein as an indicator sharp results are obtained, the end reaction being exactly at formation 1 Zeitsch. anal. Chemie, 8, 298, with cats of the crystals. 2 SABANiN and LASKOWSKY: Zeitsch. anal. Chemie, 17 (1878), 73; Jour. Chem. Soc.j 1878, Abs., 342. The reaction was declared earlier in a Russian Dissertation by Sarandinaki, and in Ber. d. chem. Ges., 5(1872), 1100. 3 WARINGTON: Jour. Chem. Soc., 28 (1875), 929, 927. CITRIC ACID. 89 of K 3 C 6 H 5 O 7 , or the corresponding sodium salt. 1 In production of this normal salt each c.c. of a normal alkali solution represents 0.070 gram crystallized, or 0.064 of anhydrous acid. For gravimetric estimation the precipitation most approved is that of barium citrate, to be weighed as sulphate. 2 It is most complete in solution of alcohol of 0.908 specific gravity. Pre- viously the citric acid is obtained as alkali citrate ; if free, by neutralization with soda; if combined with a non-alkali base, by warm digestion with an excess of sodium hydroxide or potassium hydroxide, filtering and washing the filtrate being neutralized by acetic acid. In either case the carefully neutralized and not very dilute solution is treated with a slight excess of exactly neutral solution of acetate of barium, and a volume of 95 per cent, alcohol, equal to twice that of the whole mixture, is added. The precipitate is washed on the filter with 63 per cent, alcohol, and dried at a moderate heat. The citrate of barium contains a variable quantity of water, and is transformed into sulphate of barium by transferring to a porcelain capsule, burning the filter, and heating with sulphuric acid several times till the weight is constant. 3BaSO 4 : 2H 3 C 6 H 5 O 7 . H 2 O : : 1 : 0.601. Hager di- rects that barium or calcium citrate (washed with alcohol) be dried at 120 to 150 and weighed. Ba 3 (C 6 H 5 O 7 ) 2 : 2H 3 C 6 H 5 O 7 . H 2 O : : 1 : 0.53232. For estimation in Fruit Juices see Tartaric acid,/ 1 (Waring- ton, Fleischer). g. In commerce the first form of citric acid is concentrated lemon-juice, lime-juice, and bergamot-juice, sometimes contain- ing alcohol added for preservation, and liable to contain formic and acetic acids from decomposition. Crude calcium an' mag- nesium citrates are made for transportation. In the citric acid manufacture normal calcium citrate is precipitated, and this is transposed with dilute sulphuric acid. Among impurities tar- taric acid is the most frequent adulteration, being sometimes substituted altogether in some medicinal preparations, especially in dry " citrate of magnesia." Lead may be present from manu- facture or storage, and calcium salt and traces of sulphuric acid may be left from manufacture. The detection of Tartaric acid may be done by its potassium precipitation, applied as described under that acid at d, or by its reduction of dichromate in the way specified under Tartaric acid, d. Phosphoric acid is said to be 1 THOMSON, 1883: Chem. Neics, 47, 135; Jour. Chem. Soc., 44, 826. 2 J. CREUSE: American Chemist, i (1871), 424; Zeitsch. anal. Chemie, n (1872), 446. 90 CINCHONA ALKALOIDS. sometimes present in the citric acid of co.umerce (BARFOED). It is most clearly detected after calcining tiie alkali salt. CHAIRAMIDINE and CHAIRAMINE, CHINOI- DINE, CRINOLINE. See CINCHONA ALKALOIDS. CHRYSAMMIC ACID. See ALOINS. CINCHAMIDINE. See CINCHONA ALKALOIDS. CINCHONA ALKALOIDS. Alkaloids of the bark of species of Cinchona and certain allied genera of the cinchoneae. In the leaf and wood in very small quantities ; most abundant in the bark of the root. CONTENTS: List of alkaloids, with description of those not used; the com- mercial alkaloids; the amorphous alkaloids and chiuoidine; yield of the total and several alkaloids in different barks; chemical constitution; tabular com- parison of characteristics; enumeration of means of analytical distinction ; mi- cro-chemical distinctions; separation and estimation of total alkaloids, (l)the plan of Prollius, (2) by extraction apparatus, (3) by amyl alcohol, Squibb's process, the Br. Ph. process, (4) by ethyl alcohol, the U. S. Ph. process; sepa- ration of the alkaloids from each other, enumeration of methods; quinine sepa- ration as sulphate in detail; separation by ether, Liebig's plan; by ammonia, Kerner's plan; cinchonidine separation, as tartrate, with subsequent removal of quinine ; De Vrij's process; Muter's method ; rotatory power of the alkaloids, in methods of estimation. Quinine, analytical outline; (a) crystals and heat- reactions of the alkaloid and its salts: (&) taste and physiological effects; (c) solubilities of the alkaloid and its salts; (d) qualitative tests and their limits; (e) separations in general, from pills; (/) quantitative methods, gravimetric, volumetric, in herapathite; (g) tests for impurities; Kerner's quantitative method; the pharmacopoaial tests of U. $., Germ., Fran.; ammonia test of salts other than sulphate, and of the free alkaloid and bisulphate ; test of efflo- resced salts; Hesse's test; history of Liebig's test; Br. Ph. tests; water of crys- tallization of sulphate. Qidnid'ine, nomenclature, analytical outline; (a) crys- tals and heat-reactions; (c) solubilities; (d) qualitative tests; (e) separations; (/) quantitative work; (g} tests of puritv. Cinchonidine, analytical outline; (a) crystals and heat-reactions ; (b) effects; (c) solubilities ; (d) qualitative tests ; (e) separation ; (/) estimation; (g) tests of purity. Cinchonine, analytical out- line; (a) crystals and heat-reactions; (c) solubilities; (d) qualitative tests; (e} separations; (/) estimations; (g) tests of purity. Quinoline, production; (a) forms and heat-reactions; (&) effects; (c) solubilities; (d) qualitative tests; tests for impurities. Katrines, constitution and production, description and means of identification. Thftlline, constitution, description. Antipyrine, con- stitution, description, tests, and impurities. (Crystallizable alkaloids in italic ; amorphous alkaloids in Roman.) Quinine, Co H.> 4 X.>Oo. Pelletier and Caventou, 1820. See p. 125. " Quinidine, CooH^N^Oo. Yon TTei jningen , 1 849. ( Conchinine of HESSE.) Seep. 154. CINCHONA ALKALOIDS. 91 Cinchonine, C^HooN*/). 1 Pelletier and Caventou, 1820. See Index. Cinchonidine^ C^EL^NaO. 1 Henry and Delondre, 1833 ; Winckler, 1 844 f HESSE. Diquinicine, C 40 H 46 N 4 O 3 . HESSE, 1878. Diconchinine. Apo- diquinidine. The chief amorphous alkaloid existing in barks and found in chinoidine of commerce (p. 94). Fluo- resces in sulphuric acid solution ; gives the thalleioquin reaction ; rotates to the right ; forms only amorphous salts ; and does not yield quinicine. Its relation to quinine or qui- nidine is shown by the equation: 2C 00 H 04 NoO H O C^H^N^Og. Dicinchonicine. HESSE, 1 878. Dichonchonine. Apo-dicincho nine. Derived from cinchonidine and cinchonine ; found in chinoidine of commerce ; probably existing in amorphous condition in the bark ; has not been completely isolated. (CggH^JS^O ? ) See Amorphous Alkaloids of Cinchona, p. 94. [Quinicine, C 20 H 24 N 2 O 2 . PASTEUR, 1853 ; HOWARD, 1872 ; HESSE, 1878. Formed by melting sulphates or other salts of quinine or quinidine. Also by action of light. Not found in cinchona barks. Not fluorescent. Gives the thal- leioquin reaction. Rotates feebly to the right. Amorphous, but can give rise to certain crystalline salts.] [Cinchonicine, C 19 H 22 N 2 O. PASTEUR, 1853; HOWARD, 1872; HESSE, 1878. Formed by melting sulphates or other salts of cinchonine or cinchonidine. Not contained in cinchona barks. Rotates to the right. Amorphous, but forms some crystalline salts.] Hydroquinine, C 20 H 2 gN 2 O 2 . HESSE, 1882. Fluoresces. Gives thalleioquin reaction. Rotates to the left. Ilydroquinidine, C 20 H 26 N 2 O 2 . HESSE, 1882 ; FORST and BOH- RINGER, 1882. Accompanies the quinidine of commerce. Also formed by action of permanganate on quinidine. Ro- tates to the left. Fluoresces. Gives the thalleioquin reac- tion. Ilydrocinchonidine, C 19 H 24 N 2 O. HESSE, 1882. Found in com- mercial cinchonidine (when this is not in loose needles). Rotates to the left. Not fluorescent. The pure base melts below 100 C. Heated with acids it becomes amorphous. ! SKRAUP, 1877; LAURENT, 1848. The formula C 20 H 24 N 2 O, which has been long accepted, is from RKGNAULT, and supported by Hlasiwetz, 1851. Skraup: Chem. Centr., 1877, 629; Liebig's Annahn, 197, 226. 92 CINCHONA ALKALOIDS. In the bark of Remijia Purdieana and 12. pedunculata (61 cuprea). 1 Quinamine, C 19 H 24 N 2 O 2 . (Found in other barks, though most abundant in "cuprea" bark.) Dextrorotatory. HESSE, 1872, 1877; OUDEMANS, 1879. With sulphuric acid and a trace of nitric acid, colors orange to red. Conquinamine* C 19 H 24 N 2 O 2 . Quinidamine. Accompanies qui- namine. HESSE, OUDEMANS, 1881. Quinainidine and Qninamicine, amorphous isomers of quinamine. Homoquinine. In " cuprea bark/' A compound of Cupreine, C 19 H 22 N 2 O 2 , and quinine, into which two alkaloids it splits and from which it may be synthesized. Levorotatory. PAUL and COWNLEY, 1881, 1885 ; Hesse, 1885. 2 Oiiwhonamine, C 19 H 24 N 2 O. AENAUD, 1881, 1885; HESSE, 1885 ; SEE and KOCHEFONTAINE, 1885. Dextrorotatory. Colored reddish-yellow by sulphuric, yellow by nitric acid. With nitrates forms characteristic insoluble crystals ; hence proposed as a test for nitrates (PTiar. Jour. Trans., [3], 15, 772). Of a strong toxic effect. Cusconine, C 23 H 26 N 2 O 4 . HESSE, 1877, in barks shipped from Cusco, in Peru. Difficult of crystallization. Rotates to the left. Accompanies Aricine. Concusconine, C 23 Ho 6 N 2 O 4 . HESSE, 1883. Dextrorotatory. With sulphuric acid gives a green color. Free alkaloid is tasteless. Chairamine, C 22 H 26 N 2 O 4 . HESSE, 1884. Dextrorotatory. Conchairamine, C 22 H 26 N 2 O 4 . HESSE, 1884. Dextrorotatory. Chairamidine, C 22 H 26 S 2 O 4 . HESSE, 1884. Amorphous. Dex- trorotatory. Oonchairamidine, )0 22 H 26 N 2 O 4 . HESSE, 1884. Levorotatory. Turns green with sulphuric acid. In other barks. Paytine, C 21 H 24 K 2 O. In 1870, from a white Cinchona bark from Payta~. Levorotatory. With chlorinated lime gives a dark red color. See, further, WULFSBERG, 1880. 3 Aricine, C 53 H 28 ]N" 2 O 4 . HESSE, 1879. PELLETIER and CORIOL, in 1829, in* a bark from Arica. Found by HESSE, in 1882, in "cuprea" bark. Levorotatory. Not bitter, astringent taste (Ilusemanrfs "Pflanzenstoffe"). 'Hesse's summary: Jour. Chem. Soc., 1885, Abs., 64. * Phar. Jour. Trans., [3], 15, 221, 401. Liebig's Annalen, 230, 55. *Phar. Jour. Trans., [3], u, 269. CINCHONA ALKALOIDS. 93 Paricine, C 16 H 18 N 2 O. Winckler, 1845. In bark from Para. FLUCKIGER, 1870. Cinchotine, C 19 H 24 lSr 2 O. The Hydrocinchonine of WILLM and CAVENTOU. Accompanies cinchonine. Dextrorotatory. SKRAUP, 1879. FORST and BOHRINGER (1882) find it not an oxidation product, as they had before stated (1881). Cvnehamidine, C 20 H 26 N 2 O. Accompanies cinchonidine. Levo- rotatory. HESSE, 1881. The existence of Homocinchonidine (HESSE, 1877) is denied by SKRAUP (1880). Hesse's Hydrocbnquinine is believed by FORST and BOHRINGER to be identical with hydroquinidine. Hesse (1885) reports that the substance previously (1883) named by him as Concusconidine proves to be a mixture of alkaloids. Pay tarn ine is an amorphous alkaloid accompanying Paytine. Of artificial products, the purpose of this work requires description of only Quinoline, C 9 H 7 N. Produced from cinchonine and other sources. See Index. Kairines, C 10 H 13 NO. Derivatives of quinoline. Thalline, C 10 H 13 JSrO. A methyl kairine. The list of natural cinchona alkaloids above given is designed to include all those whose separate identity remains established, by the evidence published, up to 1886, but some omissions may have been made. The artificial derivatives, oxidation products, etc., are excluded from the list above, and have only a brief general history under Chemical Constitution of Cinchona Alka- loids. It will be observed that the present chemistry of cinchona' alkaloids agrees with the chemistry following the work of Winck- ler in 1847 and Pasteur from 1853, in the fundamental out- lines affecting the alkaloids in use, those most abundant in barks of the cinchona family as a whole. It is stated now, as it was over thirty years ago, that the two isomers quinine and quinidine, with the two isomers cinchonine and cinchonidine, constitute the greater part of the crystallizaUe alkaloids of the cinchonas. All the crystallizable alkaloids in use under pharmacopoeia! authority are carried under these four names. In elementary constituents, cinchonine and cinchonidine have each one atom of oxygen less in the molecule, and, according to recent determina- tions, have each CH less in the molecule than quinine and cin- chonine: C 2? R 24 N 2 2 -C 19 R 22 N 2 0=CE 2 +0. To a limited extent other crystallizable alkaloids of cinchona are certainly carried into use under the names of the four princi- pal alkaloids. It is specifically stated that hydroquinidine ac- 94 CINCHONA ALKALOIDS. companies commercial quinidine ; that hydrocinchonidine and cinchamidine are found with commercial cinchonidine^ and that cinchotine sometimes contaminates cinchonine. Hydroquinine may go with manufactured quinidine or quinine, being found in the mother-liquors of the former. Quinamine, and probably conquinamine, are found in other barks besides " cuprea " bark, and may find their way into manufactured salts, where they should then be detected by reactions with sulphuric and nitric acids. Then the amorphous products quinicine and cinchonicine may be carried into crystalline forms of salts to some extent. And it is always understood that separations of cinchona alka- loids in manufacture are not absolute, so that the quinine salts of the market always contain, under certain limits, cinchonidine and cinchonine, perhaps quinidine, and under narrower limits may contain the amorphous alkaloids in general. The quinidine of commerce, according to Hesse, 1875, consists most often of cinchonidine with a little quinine. Amorphous cinchona alkaloids. The name Chinoidine (Q\\i- noidine) was given by Sertiirner, in 1828, to the amorphous alka- loidal substance left after separating quinine and cinchonine as then known, and which he believed to be a distinct alkaloid. Chinoidine was recognized as an easily fusible base, of strong alkalinity, forming uncrystallizable salts, and of full virtues as a febrifuge. Until about 1855 it was prepared, in connection with the crystallizable alkaloids, by uniform methods, from Calisaya barks of good strength, and therefore possessed a fairly constant character. About 1 847 Winckler stated that chinoidine was in large part an amorphous transformation product of the crystalli- zable alkaloids of cinchona then known. During investigations commencing about 1853 Pasteur made it known that by fusing for some time a salt of one of the crystallizable alkaloids, or, in part, by hot digestion in acidulous solution, an amorphous modi- fication is obtained, without change of elementary composition. The amorphous product of quinine and of quinidine he named Quinicine; and the amorphous product of cinchonine and of cinchonidine he named Cinchonicine ; and it has been generally believed that these are the uncrystallizable alkaloids which exist already formed in the barks, as well as result from chemical treat- ment of the barks. All barks contain amorphous alkaloids; sometimes the larger portion of the alkaloids is amorphous. And the amorphous alkaloidal matter of cinchona has been in e;reat part accounted for according to the nomenclature of Pasteur, almost down to the present time, so that we have had the familiar classification of the leading natural cinchona alkaloids, as follows : CINCHONA ALKALOIDS. 95 C 20 H 24 N 2 O 2 : Quinine, Quinidine, [Quinicine]. C 20 H 24 N 2 O : Cinchonine, Cinchonidine, [Cinchonicine]. Howard, in 1872, found quinicine and cinchonicine, made from quinine and cirichonine, to be capable of crystallizable com- binations, while no salts crystallizable could be produced from natural amorphous alkaloids. And Hesse affirms (1878) that quinicine and cinchonicine, as isomers of quinine and cinchonine, are not present in the barks, are not formed to any great extent by ordinary methods of manufacture, and not found in chinoidine. They would be formed in the manufacturing treatment, the melt- ing of chinoidine, only so far as the crystallizable alkaloids are subjected to this treatment, for it is stated by Hesse that the chief natural amorphous alkaloids, taken from the bark or from chinoidine, are not convertible into quinicine or cinchonicine, which are partly crystallizable. The most prominent natural amorphous alkaloids, those making up the larger part of the by- product chinoidine, according to fiesse, are (with a little liberty in translating Hesse's nomenclature) diquinicine and dicinchoni- cine, amorphous alkaloids having the constitution of anhydrides (apo-derivatives) respectively of quinine and cinchonine (see the equation under Diquinicine, p. 91). In this view the leading natural cinchona alkaloids are to be grouped as follows : Crystallizable. Amorphous. C 20 H 24 N 2 O 2 : Quinine, Quinidine. C 40 H 46 N 4 O 3 : Diquinicine. C 19 H 22 N 2 O : Cinchonine, Cincho- CggH^N^O ( ? ) : Dicincho- nidine. nicine. By heating the chief crystallizable cinchona alkaloids with hydrochloric acid, at 140 to 150 C., in sealed tubes, for 6 to 10 hours, HESSE (1880) * obtained an apo-derivative from each. Apoquinine and apoquinidine each had the formula C 19 H 22 N 2 O 2 , the removal of CH 2 being effected by production of CH 3 C1, and both these new alkaloids were found to be amorphous in all their salts. They gave the thalleioquin reaction, were soluble in ether or alcohol, and showed fluorescence. Apocinchonine and apo- cinchonidine were each C 19 H 22 N 2 O, isomeric with cinchonine, and each was crystallizable. But a diapocinchonine, C 38 H 44 .N 2 O 2 , forming only amorphous salts, was obtained, readily soluble in alcohol, ether, or chloroform, and, Hesse states, distinct from the natural alkaloid dicinchonicine (p. 91), as well as from cinchoni- cine, formed by melting. 1 Ber. deut. cfiem. Ues., 205, 314; Jour. Chem. Soc., 1881, Abs., 615; Am. Jour. Phar., 53, 105, 160. 96 CINCHONA ALKALOIDS. The amorphous alkaloids difficult of separation have been less satisfactorily studied than the crystallizable ones, and it is strongly probable that diquinicine and dicinchonicine very imper- fectly represent the amorphous alkaloids of the barks. Chinoi- dine usually contains quinidine in proportion larger than that of the other crystallizable alkaloids. Further than this it has as yet only been ascertained, that quinamidine and quinamicine are amorphous alkaloids found in some other barks besides those of Remijia ; and that cusconine, chairamidine, and paytamine are amorphous accompaniments of the special crystallizable alkaloids of certain exceptional barks. Elementary analysis has been ob- tained of all these except paytamine. Yield of Cinchona Alkaloids. Of total alkaloids : 1 In barks of different species and localities, from a maximum of about 15 per cent, to entire absence of alkaloids, " Calisaya Ledgeriana, Java, 80 specimens, MOENS, 1879, 12.50 to 1.09 per cent. " Calisaya Javanica, DE VRIJ, 1879, 10.3 to 1.3 per cent. " Cinchona officinalis, BROUGHTON, 1872, 6.9 to 3.1 per cent. " C. succirubra, Java, 1881, 9.8 to 3.2 per cent. " China regia, 1855, 0.99 per cent. In China cuprea, 5.9 to 2 per cent. " "Cinchona" of U. S. Ph., dried at 100 C., at least 3 per cent. " " Eed Cinchona Bark " of Br. Ph., between 5 and 6 per cent. " " Cinchona Barks" of Ph. Germ., at least 3J per cent. " Cinchona barks, Ph. Fran., at least 2J per cent. In Eed barks, at least 3 per cent. Of Quinine : In Cinchona succirubra, Java, harvest of 1881, MOENS, 2.5 to 0.4 per cent. " C. Ledgeriana, Java, 1879, 11.6 to 0.8 per cent. " C. officinalis, India, 1872,, BROUGHTON, 4.18 to 1.6 per cent. " "Bed Cinchona" and in Yellow C.," dried at 100 C., U. S. Ph., at least 2 per cent. " " Red Cinchona bark," Br. Ph., at least 3 per cent, quinine and cinchonidine. 1 For a report of the yield of individual and total alkaloids in 13 Bolivia Cinchona Barks, see STOEDER, 1878: Archiv d. Phar., [3], 13, 243; Am. Jour. Phar.,$i, 22. CONSTITUTION. 97 In Red Cinchona bark, Ph. Fran., at least 2 per cent, quinine as sulphate. Of Cinchonidine : In C. succirubra, Java, harvest of 1881, MOENS, 5.2 to 1.3 per cent. " C. Calisaya, 1873, MOENS, 8 samples, 1.2 to 0.4 per cent. Of Cinchonine : In C. Calisaya, 1873, MOENS, 8 samples, 1.1 to 0.1 per cent " China de Quito rubra, RBICHAKDT, 0.39 per cent. " China Huanuco, Keichardt, 2.24 per cent. Of Quinidine : In C. Calisaya, 1873, MOENS, 8 samples, 0.9 to 0.86 per cent. " China cuprea, in comparative abundance, Gehe & Co., 1884. Constitution of Cinchona Alkaloids. The derivation of cin- chonine and quinine from Quinoline, C 9 H 7 N, inferred by Weidel in 1873, has acquired additional light every year, and promises to become clearly understood. The remarkable interest of the pyridine series and the derived quinoline series, in relation to natural alkaloids, is mentioned under Midriatic Alkaloids, with a statement of the central position of pyridine in the theoreti- cal chemistry of natural alkaloids. Quinoline was obtained by Gerhard t in 1842 by distilling quinine with potash, and is so obtained from certain other alkaloids, cinchonine, strychnine, brucine. It is also found in considerable quantity in the heavier distillates (dead oil) from coal-tar. The hypothetical formulae of pyridine and quinoline, as aromatic compounds analogous to ben- zene and naphthalene, with N in the place of one CH in the benzene ring and naphthalene double ring, was proposed about 1870. The midriatic base tropine is derived from pyridine. The synthesis of quinoline has been effected in several ways; that by Skraup in 1881, from aniline, nitrobenzene, and glycerine, is a practical working method, yielding quinoline identical with that distilled from cinchona alkaloids : 2C 6 H 7 N (aniline) +C 6 H5^O 2 (nitrobenzene) + 3C 3 H 8 O 3 (glycerine) = 3C 9 H 7 K (quinoline) -f- 11H 2 O. Since about 1880 there has been a most active interest in the field of pure chemistry lying between the quinoline series on the one side and the natural cinchona alkaloids on the other side. A vast amount of well-directed experimental work has been done, and great numbers of derivatives, both of the quino- line bodies and of cinchona alkaloids, have been produced and 93 CINCHONA ALKALOIDS. examined. It is an opinion sustained by men acquainted with the methods and difficulties of organic synthesis that quinine will be produced artificially. Meantime artificial quinoline de- rivatives, such as those brought before the world as Kairines, have been found to present physiological effects like those of quinine. ^ As to the commercial production of quinoline itself, as a medicinal material, should its products come into general demand, it would perhaps continue to be made from cinchonine, unless manufacturers should exercise great care, in its production by Skraup's process, to avoid contamination with nitrobenzene (p. 97). It is to be observed that both pyridine and quinoline bases have the characteristic of holding H 2 , H 4 , II 6 in addition com- binations. The hydrogenized members of the quinoline series (hydroquinolines), with various substitutions, take character ap- proaching that of the natural alkaloids. The gradually accumu- lating evidences, to which references are below given, render probable the following rational formulae, with two quinoline nuclei in the alkaloid molecule : Cinchonine : C 9 H 10 N . C 9 H 9 N . (O . CH 3 ) = Quinine : C 9 H 10 K . C 9 H 8 N . (O . CH 3 ) 2 Both quinoline and pyridine tend to form tetra-hydrides ; and tetrahydro-quinoline, C 9 H 7 [H 4 ]N, or CgH n ]S", is fruitful of de- rivatives having resemblances to natural alkaloids. In the hypo- thetical formulae for cinchonine and quinine, the quinoline tetra- hydride molecules drop an atom of hydrogen for union with each other, and another atom of hydrogen for each molecule of meth- oxide (O.CH 3 ) taken. The systematic names, therefore, are respectively methoxy-tetrahydro- cliquinoline and dimethoxy- tetrahydro-diquinoline. 1 J L. HOFFMAN and W. KONTGS, 1883: Ber. deut. chem. Ges., 16, 727; Jour. Chem. Soc., 1883, Abs., 1143. KONIGS, with COMSTOCK and with FEER, 1885, 1884, with G. KORNER, 1884. KONIGS. 1881: Ber. deut chem. Ges., 14, 1852; Jour. Chem. Soc., 1882, Abs., 224: 1880: Ber. deut. chem. Ges., 13, 911. SKRAUP, 1879: Ber. deut. chem. Gea., 12, 1107: Jour. Chem. Soc., 36, 810. WICHNEGRADSKY (structure of cinchonine with both a quinoline and a pyri- dine nucleus), 1881: Bull.S"C. Chim., [2], 34, 339; Jour. Chem. Soc., Abs., 444. DE CONINCK, 1882-83. KN^RR and ANTRICK (positions in the structure of quino- line), 1884: Ber. deut. chem. Ges.. 17. 2870, 2032: Jour. Chem. Soc., 1885, Abs., 273: 1884, Abs., 1378. CLAUS and others. Diquinolines : WILLIAMS, 1881, Chem. Neivs, 43, 145: CLAUS, 1881-82; DEWAR, 1881; TRESSIDER, 1884; FISCH- ER (and Loo), 1 884, 1885 ; OESTERMAYER, 1885. KRAKAU, 1885. BEREND, HARTZ, KAHN, SPADY, EINHORN, 1885-86. MICHAEL. 1885: Am. Chem.. Jour., 7, 182. "Ladenburg's Handworterbuch der Chemie," i. 243-298, ii. 532-595 (63 pages on quinoline). Summaries of progress, 1882-85: Am. Chem. Jour., 4, 64, 157; 5, 60, 72; 7, 200, (182). COMPARATIVE CHARACTERISTICS. 99 s " ^4. -SS o bo c ^ Levorot Sulphates soluble i Normal tartra ll 1 . .2 5 3 Sfi III g a Q &l.| i ' S$S = fl l I qj .S.s "" .5.3.2 . SHI " o ~ " 2. Sl8.,.J J ISg til IP s Give < thalleioqu !!! IS! Ill PI 2^ S-Ct 111 o'C'SS' S|l is I* u*g i 111! IIP S^= o >> 1^1 = s *ilf 35 i* w'S ffil k E,^ ill I -%iii S|l! sSai g-S^* ^isi .S * x oo HS.S ?!if |||s eill loll *--= 'g'c S^ ml ?i=i 5 o s 50 "3 * y> a) ioo CINCHONA ALKALOIDS. CINCHONA ALKALOIDS, DISTINCTIONS between (for test-methods, conditions, etc., see under each alkaloid, d) : I. OF QUININE. A. From Cinchonidine and Cinchonine: 1. Fluorescence, in aqueous solutions of the sulphate and other oxy-salts. 2. The'thalleioquin test with bromine or chlorine followed by ammonia. 3. Sulphate crystallization. 1 p c i nc lK>nine more perfectly 4. Solution in ether. than from dncbonidine. 5. Solution in ammonia. 6. Formation of herapathite, a crystalline iodosulphate. 7. Rotatory difference : from cinchonine, in direction ; from cin- chonidine, in degree. 8. Microchemical examinations (p. 101). B. From Quinidine : 1. Sulphate crystallization. 2. Non-precipitation by potassium iodide. 3. Non-solution of the sulphate in chloroform. 4. Formation of herapathite. 5. Rotatory difference, in direction. II. OF CINCHONIDINE. A. From Quinine (I. A, 1, 2). B. From Cinchonine: 1. Tartrate precipitation. 2. Chloroformic solution of sulphate. 3. Rotatory difference, in direction. 4. Greater solubility in alcohol and in ether. C. From Quinidine: 1. Tartrate precipitation. 2. Non-precipitation by iodide. 3. Non-solution of sulphate in chloroform. 4. Rotatory difference, in direction. III. OF AMORPHOUS ALKALOIDS. A. From the crystallizahle alkaloids: 1. By non-crystallization of the sulphate, and other salts, and the free alkaloid, under ordinary or microscopic observation. B . From Gin ch o nine : 1. By greater solubility in ether, or in dilute alcohol. MICROCHEMICAL DISTINCTIONS. 101 Microchemical distinctions between cinchona alkaloids. SCHRAGE (1874 and 1879), GODEFFROY and LEDERMANN (1877), and HESSE (1878) have made contributions respecting distinc- tions drawn from the crystals formed under the microscope after adding potassium sulphocyanate solution. 1 Godeft'roy and L. used saturated solutions of sulphates of the several alka- loids. Schrage used a solution of the alkaloklal salt in 100 parts of water, converting the sulphate of quinine into hydrochloride for the purpose, fiut Hesse advises to use only saturated solu- tions of the alkaloid sulphates, prepared by dissolving in warm water and leaving in the cold till crystallization stops. Such a solution, by itself, should not exhibit crystals under the micro- scope. The sulphocyanate solution should be very concentrated, 1 part of the salt to 1 part of water. A drop of the alkaloid sulphate solution is placed on a glass slide, and a drop (Hesse), or a third to a fourth of drop (Schrage), of the reagent is placed on one side of the alkaloid solution, a cover-glass is put over, and the slide is placed, in level, under a power of about 110 diameters. With Schrage's proportions the crystal forms were completed in from a half-hour to several hours ; with Hesse's proportions, in a few minutes to half an hour. In first contact with the reagent amorphous precipitation frequently occurs, followed by crystallization. The authors above cited differ from each other in certain important particulars. Thus, with quinine, Godeffroy and Ledermann assert that the sulphocyanate, so far as formed, is in amorphous globules as a final form, and that any stellate groups of crystals are those of unchanged quinine sul- phate. Schrage, later, states that the amorphous globules are resolved into stellate clusters of crystals. And Hesse states that Godeffroy's appearances, with quinine, were due to presence of cinchonidine. The analyst who would undertake the identification of impu- rities in cinchona alkaloids by the sulphocyanate reaction, or other test, in crystalline forms under the microscope, should govern his conclusions by the results of strictly parallel tests, made at the same time with alkaloids of known purity. The concentration of the alkaloidal salt solution and of the reagent, and the proportion of the one liquid to the other, must be held 1 SCHRAGE, Archiv d. Phnr., [3], 5, 504: 13, 25; Pro. Am. Pharm., 23, 409; 27, 488. GODEFFROY and L., Archiv d. PJiar., [3], II, 515: New Remedies, 7, 107 (April, 1878): Am. Jour. Phar., 50, 158; Pro. Am. Phorm., 26, 569. O. HESSE, Archiv d. Phar., [3]. 13, 481; Pr>. Am. Pfiarm., 27, 492. The pub- lications above cited are illustrated with cuts. On the Identification of Alka- loids in general by Crystallization under the Microscope, a full report is made by A. PERCY SMITH, 1886: Analyst, n, 81 (illustrated). 102 CINCHONA ALKALOIDS. without variation, and the disturbing influence of evaporation must be prevented by the cover-glass at once. It is not prudent to base conclusions upon a resemblance to forms figured by other operators. Even slight differences in the purity of the reagent or in the atmospheric temperature may cause differences in the form or the rate of crystallization. The quinidine sulphocya- nate crystals are more characteristic than those of the other alka- loids, and the reaction with potassium iodide is likewise a favor- able one for microscopic recognition of quinidine. SEPARATION AND ESTIMATION OF CINCHONA ALKALOIDS. Se- paration of the total Alkaloids from Cinchona Barks. Cin- chona alkaloids exist in the barks in combination with the tannin known as cinchotannic acid (DE YRIJ, 1878). Kinic (quinic) acid is also present in the bark, and, under action of certain solvents, unites with a part of the alkaloids. The cinchotan nates of the alkaloids are almost insoluble, while the kinates are solu- ble, in cold water. Acidulated water readily dissolves the en- tire alkaloids. In methods of analysis, with a few exceptions, the alkaloids, are liberated by lime or other alkali, and - dissolved from the powdered bark, in a free state, by alcohol, ether, or other solvent of the free alkaloids. But a removal of the alkaloids as hydro- chlorides is sometimes resorted to. The most favorable opera- tions *for removal of the alkaloids from the bark may be clas- sified as follows : 1. The powdered bark is macerated in a mixture of chloro- form or ether, with alcohol and ammonia, and an aliquot part of the total liquid is taken (without washing) for the analysis (PROLLIUS, 1882; DE YRIJ, 1882; Ph. Germ.) 2. The powder mixed with lime is exhausted with ether in an extraction apparatus, Tollens's or other. 3. The powder mixed with lime is exhausted by digesting with a mixture of amyl alcohol and ether f SQUIBB, 1882), or ainyl alcohol and benzene (Br. Phar., 1885). 4. The powder mixed with lime is exhausted by digesting and washing with alcohol (DE YRIJ, 1873; U. S. Ph., 1880, p. 78). 5. The acidulous decoction, in a part of the filtrate taken as a fraction of the total solution, is precipitated by picric acid, and the dried precipitate weighed (HAGER, 1869 ; given in this work under Alkaloids, p. 49). The use of an extraction apparatus, best adapted to ether as a SEPARATION AND ESTIMATION. 103 solvent, is a most rigidly exact and generally satisfactory way in this as in most solvent operations upon plants. But it loads the solution with more coloring and other extraneous matters, and takes longer, than the method placed first above. An aliquot part of the liquid, taken with due precautions, gives the operator quick and trustworthy results, and for ordinary uses this plan is here given the preference. Other operators prefer percolation or hot digestion, or both. The plans above enumerated have been carried out, in many cases with separation of the alkaloids from each other, or of the quinine from the other alkaloids, by different chemists, as follows : 1. Methods on the Plan of Prollius. 1 The directions of the German Pharmacopoeia of 1882 are in effect as follows: Pre- 1 PROLLIUS, 1881: Arch. d. Phar., 209, 85, 572; Am. Jour. Phar., 54, 59; New Bern., u, 22. J. BIEL, 1882: Phar. Zeitschr. Ruasland, 21, 250. DE VRIJ, 1882: Jour, de Phar. et deChim.; New Rem., n, 258; Am. Jour. Phar., 54, 59. KISSEL, 1882: Arch. d. Phar., 220, 120. Ph. Germ., 1882, 63. FLL'CK- IGER. 1883: Phar. Zeit., vol. 28 ; New Rem., 12, 274. A. PETTIT, 1884. Ci- tations from above-named authorities: Zeit. anal. Chem., 22, 132; Proc. Am. Pharm., 30, 204; 31, 133, 134. Prollius proposed the ethereal solvent mixture (making it by weight of ether 88 per cent., of ammonia-water 4 per cent., of 92 to 96 per cent alcohol 8 per cent.) for assays of the ether-soluble alkaloids only, and directed a chloroform mixture for assays of the total cinchona alkaloids. But Biel, and Kissel, and I)e Vrij agree in the statement that Prollius's ethereal solvent removes all the alkaloids. Prollius, however, used only half as much of the solvent as is* here directed, according to De Vrij. De Vrij emphasizes the required fineness of the powder. He would prefer a less aqueous solvent, made by saturating the alcohol with ammonia, and adding the ether. Biel says the time of maceration should be four hours, neither more nor less, while 'De Vrij found one hour enough as shown by control experiment. Kissel obtains the quantity of the pure alkaloids by subtracting from the quantity of crude alkaloid the weight of resins, wax, etc., left on a tared filter, in filtration of a solution of the crude alkaloidal residue in diluted sulphuric acid. The chloroformic solvent of Prol- lius, above referred to, consisted of 76 percent, alcohol, 20 percent, chloroform, and 4 per cent, ammonia-water. The solution was wine-red, and to decolorize it a quantity of finely powdered calcium hydrate equal to the quantity of the bark is agitated with the decanted solution, which is then filtered, and this fil- trate is weighed to obtain an aliquot part of the entire solvent taken. The weighed filtrate is evaporated, and the dried residue weighed as total alkaloid, not purified further. In the use of the ethereal solvent Prollius decanted the clear solution (as in the directions above), and then supersaturated the ethereal solution with diluted sulphuric acid, when the alkaloidal salts were found in a dense aqueous layer. The ethereal layer was removed and washed, once with 2 c.c., then with 1 c.c. of water, the washings being added to the alkaloid solu- tion. Prom the latter the alcohol is evaporated, when ammonia is added just to alkaline reaction, and the precipitate dried in a tared capsule and weighed. The ethereal solution, if not distilled, should be evaporated in a flask or beaker of some depth to avoid creeping. The purification of the crude alkaloids is a matter distinct from the removal from the bark, and may be varied at will of the operator. The separation by shaking out with chloroform (p. 33) will gene- rally be preferred to precipitation by the Ph Germ. 104 CINCHONA ALKALOIDS. pare the solvent mixture by taking together 85 parts by weight of ether (s.g. 0.724 to 0.728), 10 parts of alcohol (0.830 to 0.834), and 5 parts of ammonia-water (s.g. 0.960), making 100 parts by weight. Treat 20 grams of the powdered cinchona with 200 grams of the solvent mixture, agitating thoroughly and repeat- edly, macerate one day, and pour off 120 grams of the clear liquid. Add 30 c.c. of decinormal ' solution of hydrochloric acid, remove the ether and alcohol by distillation or evaporation, concentrating the volume to 30 c.c., and, if necessary, add more hydrochloric acid until the solution has an acid reaction. Then filter, and when cold add 3.5 c.c. of normal solution of potassa. After the alkaloids have separated add to the clear supernatent liquid enough potassa solution to complete the precipitation. Collect the whole precipitate upon a filter, and wash with small portions of water, successively poured on, until drops of the washings, when allowed to glide over the surface of a 'cold-satu- rated aqueous solution of quinine sulphate, no longer produce a cloudiness. After allowing the alkaloids to drain press them gently between bibulous papers, and dry them by exposure to the air until they can be perfectly removed to a glass capsule. Then dry them over sulphuric acid, and finally to a constant weight on the water-bath. Of 200 grams total liquid, 120 grams were decanted, and 3:5:: weight obtained : a?= weight of mixed alkaloids in the 20 grams of bark. Then a?x5= per cent, of alkaloids in the bark. Directions in detail for precautions against error, contri- buted by De Vrij and others for the method of Prollius, are presented as follows (observe last two foot-notes) : The bark is to be very finely powdered. If of over 4$ total alkaloids, take 10 grams, otherwise 20 grams for an assay. Place the weighed portion of the powdered bark in a glass-stoppered bottle pre- viously tared, add of the ethereal solvent (above) 20 times the weight of the powder, take the exact total w r eight of bottle and contents, and agitate from time to time for four hours (BiEL. One hour, DE VKIJ. One day, Ph. Germ.) If any loss of weight is found, add of the solvent to restore it, and agitate and weigh again. Decant carefully so much of the solution as can be obtained per- fectly clear (into a flask from which ether can be distilled), and by weighing the stoppered bottle find the exact weight of the decanted liquid. Distil (or evaporate) off the ether avoiding 1 The Ph. Germ, directs to add 3 c.c. of normal solution of hydrochloric acid. Fliickiger, finding the resulting volume of liquid too small for the filtra- tion, advised the 30 c.c. of decinormal solution. Also advised the concentra- tion to a definite volume of 30 c.c., not in the official directions. SEPARATION AND ESTIMATION. 105 its taking fire then transfer the residual liquid to a small cap- sule tared with a short glass rod (rinsing with a little of the sol- vent), and evaporate and dry the residue on the water-bath. Weight of alkaloidal solution decanted from the bottle : weight of total solvent taken in the bottle : : weight of residue : x = quantity of crude alkaloids in the amount of bark taken. To obtain the pure alkaloids, the residue of the crude alkaloids is dissolved in diluted hydrochloric acid, the solution filtered and the filter washed, the nitrate made alkaline with sodium hydrate and repeatedly shaken out with chloroform, the chloroformic solution evaporated (or distilled) in a tared dish, and the residue dried at 100 C. and weighed/ De Yrij found the pure alkaloids so obtained to be 16.5$ less than the crude in the case of a red Java bark. 2. Removal of the Alkaloids from the Bark l>y use of an Extraction Apparatus. For the use of an extraction apparatus upon cinchona bark, with ether as a solvent, the following ex- cellent directions of Professor FLUCKIGER are given : 1 Of a well- selected average specimen of the bark 20 grams are very finely powdered, moistened with ammonia-water, and, after standing for an hour, mixed with 80 grams of hot water ; it is then al- lowed to cool, subsequently mixed with milk of lime (prepared by triturating 5 grams of dry caustic lime with 50 grants of water), and the mixture evaporated on a water-bath until it is uniformly converted into small, somewhat moist, crumb like par- ticles. This is then transferred to a cylindrical glass tube about 2.5 centimeters (1 inch) wide and 16 centimeters (6.4 inches) long, the tube being fitted as the percolator of an extraction apparatus. The neck of this percolator is fitted with a rest of wire cloth, on which a disk of filtering-paper is held by a loose plug of cotton. The powder is packed quite compactly, and covered, at the top, with a plug of cotton which has been used to clean away the last traces of the bark. The percolator is put in place, under a condenser, in the extraction apparatus, into the receiver of which about 100 c.c. of ether is introduced, and the extraction is conducted, in the usual manner, over a water-bath for nearly a day, and until completed as shown by testing a little of the percolate. This may be tested, in the 1 " The Cinchona Barks," Power's translation, Phila., 1884, p. 69. Other solvents have been used on cinchona with an extraction apparatus. Chloroform is used in Carles's process (1873 : Zeitsch. anal. Chem., 9, 497). Methylated Ether, and doubtless alcohol or Methylated Alcohol, can be well used in a form of ex- traction apparatus that would "carry over the vapor with desirable rapidity. 106 CINCHONA ALKALOIDS. ethereal solution, by about an equal volume of potassium mer- curic iodide solution. 1 When the extraction is completed, 36 c.c. of decinormal solution of hydrochloric acid (3.64 grams in 1 liter) are added to the ethereal solution in the receiver, when the ether is distilled off, and enough hydrochloric acid then added to give an acid reaction. When cold the liquid is filtered, the filter washed, and 40 c. c. of decinormal solution of soda (4 grams in 1 liter) are added. The precipitate is left at rest till the liquid above it is clear. Sodium hydrate solution (preferably of spec. grav. 1.3) is then added to complete the precipitation, the precipitate is col- lected on a filter, and gradually washed with a little cold water until a few drops of the washings, when allowed to flow on the surface of a cold-saturated neutral aqueous solution of quinine sulphate, cease to produce a turbidity. The drained precipitate contained on the filter is then gently pressed between bibulous paper, and dried by exposure to the air. It may afterward be readily removed from the paper without loss, and, after tho- rough drying upon a watch-glass over sulphuric acid, is finally, dried at 100 C. and weighed. The weight of the precipitate, multiplied by 5, will give the total percentage of mixed alkaloids in the bark. 3. The use of ethereal or ~benzolated mixture of Amyl Alcohol to dissolve the free cinchona alkaloids, which are then trans- ferred to aqueous solution of the salts of these alkaloids. A. Squibtfs Process:* "Take of the powdered cinchona 5 grams ; lime, well burnt, 1.25 grams ; amyl alcohol, stronger ether, puri- fied chloroform, normal solution of oxalic acid, normal solution of soda, and water, each a sufficient quantity or double all the quantities throughout, as well as the size of the vessels, etc., if 1 The ethereal solution may be treated according to the following direc- tions of FLUCKIGER, or by any desired method for purifying the alkaloids from resins, etc. 2 E. R. SQUIBB, 1882: Ephemeris, i, 106; BR. PH., 1885, 111. Squibb digests first with amyl alcohol alone, then adds ether in larger volume "to facilitate percolation and evaporation." The Br. Ph. digests with a mixture of amyl alcohol with thrice its volume of benzene. Squibb takes the alkaloids out of the amylic liquid by aqueous oxalic acid ; the Br. Ph. , by aqueous hydrochloric acid. Squibb purifies the total free alkaloids by shaking out with chloroform in alkaline mixture. The Br. Ph. undertakes the separation of the quinine with cinchonidine by precipitation as tartrates. then precipitating the remainder of the alkaloids from the filtrate as free alkaloids, these separations serving also to purify. The method of Dr. Squibb, in his unrivalled explicitness of detail, provides with great care against inefficient treatment. The approxi- mate separation with tart-rate by theBr. Ph. corresponds very nearly to Squibb's approximate division into ether-soluble and ether-insoluble alkaloids, p. 117. SEPARATION AND ESTIMATION. 107 the barks be poor, or if it be desired to divide the errors of mani- pulation. "Add to the lime contained in a 10 c.m. = 4-inch capsule 30 c.c. of hot water, and when the lime is slaked stir the mix- ture and add the powdered cinchona, stir very thoroughly, and digest in a warm place for a few hours or over night. Then dry the mixture at alow temperature on a water-bath, rub it to powder in the capsule, and transfer it to a flask of 100 c.c. capacity and add to it 25 c.c. of amyl alcohol. Cork the flask and digest in a water-bath at a boiling temperature and with vigorous shaking for four hours. Then cool and add 60 c.c. of stronger ether, of sp. gr. 0.728, and again shake vigorously and frequently during an hour or more. Filter off the liquid through a double filter of 10 c.m. =z 4: inches diameter into a flask of 150 c.c. capacity, and transfer the residue to the filter. Rinse out the flask on to the filter with a mixture of 10 volumes of amyl alcohol and 40 of stronger ether, and then percolate the residue on the filter with 15 c.c. of the same mixture added drop by drop from a pipette to the edges of the filter and surface of the residue. Eeturn the residue to the flask from whence it came, add 30 c.c. of the amyl alcohol and ether mixture, shake vigorously for five minutes or more, and return the whole to the filter. Again percolate the residue with 15 c.c. of the menstruum applied drop by drop from a pipette as before. Then put the filter and residue aside, that it may be afterward tested in regard to the degree of ex- haustion. " Boil off the ether from the filtrate in the flask by means of a water-bath, taking great care to avoid igniting the ether vapor, and also to avoid explosive boiling, by having a long wire in the flask. When boiled down as far as practicable in the flask transfer the remainder to a tared capsule of 10c.rn. = 4 inches diameter, and continue the evaporation on a water-bath until the contents are reduced to about 6 grams. 1 Transfer this to a flask of 100 c.c. capacity, rinsing the capsule into the flask with not more than 4 c.c. of amyl alcohol. Then add 6 c.c. of water and 4 c.c. of normal solution of oxalic acid, and shake vigorously and frequently during half an hour. Pour the mix- ture while intimately mixed on to a well-wetted double filter of 12 c.m. 4f inches diameter, and filter off the watery solution from the amyl alcohol into a tared capsule of 10 c.m. = 4 inches 1 If only a very rough estimate of the total alkaloids be needed, tin's may be obtained by continuing the evaporation of the amyl alcohol solution to a constant weight, and subtracting from the result a half of 1 per cent, of the weight of bark taken (SQUIBB). io8 CINCHONA ALKALOIDS. diameter. Wash the filter and contents with 5 c.c. of water ap- plied drop by drop from a pipette to the edges of the filter and surface of the amyl alcohol. Then pour the amyl alcohol back into the flask over the edge of the filter and funnel, rinsing the last portion in with a few drops of water. Add 10 c.c. of water and 1 c. c. of normal solution of oxalic acid ; again shake vigo- rously for a minute or two, and return the whole to the wetted filter "and filter off the watery portion into the capsule with the first portion. Return the amyl alcohol again to the flask, and repeat the washing with the same quantities of water and normal oxalic acid solution. When this has drained through, wash the filter and contents with 5 c. c. of water applied drop by drop from a pipette. Evaporate the total filtrate in the capsule on a water- bath at a low temperature until it is reduced to about 15 grams, and return this to a flask of 10(1 c.c. capacity, rinsing the cap- sule into the flask with 5 c.c. of water. Add 20 c.c. of puri- fied chloroform, and then 6.1 c.c. of normal solution of soda, and shake vigorously for five minutes or more. While still inti- mately mixed by the shaking pour the mixture upon a filter 12 c.rn. = 4f inches diameter, well wetted with water. When the watery solution has passed through, leaving the chloroform on the filter, wash the filter and chloroform with 5 c.c. of water applied drop by drop. Then transfer the chloroform solution, by making a pin-hole in the point of the filter, to another filter of 10 c.m. = 4 inches diameter, well wetted with chloroform, and placed over a tared flask of 1 00 c.c. capacity. Wash the watery filter through into the chloroform- wet filter with 5 c.c. of the purified chloroform, and, when this has passed through into the flask, wash the chloroform-wet filter also with 5 c.c. of chloro- form applied drop by drop to the edges of the filter. When the whole chloroform solution of alkaloids is collected in the flask, boil off the chloroform to dryness in a water-bath, when the alka- loids will be left in warty groups of radiating crystals adhering over the bottom and sides of the flask. Place the flask on its side in a drying-stove, and dry at 100 C. to a constant weight. The weight of the contents multiplied by 20 gives the percentage of the total alkaloids of the cinchona in an anhydrous condition, to within 0.1 or 0.2 of a per cent, if the process has been well managed." l B. Br. Ph. Process. (1) For Quinine and Cinchonidine : " Mix 200 grains [or 12.5 grams] of the (red) cinchona bark, in 1 For an " Estimation of the Quinine," as represented by an ether-soluble division of the alkaloids, following the above method, by the same author, see p. 117. SEPARATION AND ESTIMATION. 109 . No. 60 powder, with 60 grains [or 4 grams] of Irfsi^ate J^f cal- cium ; slightly moisten the powder with \ oz. [14 c.c.] of water ; mix the whole intimately in a small porcelain dish or mortar ; allow the mixture to stand for an hour or two, when it will present the characters of a moist, dark-brown powder, in which there should be no lumps or visible white particles. Transfer this powder to a six-ounce flask [one of about 170 c.c. capacity], add 3 fluid ounces [85 c c.] of benzolated amyl alcohol [amyl alcohol, 1 volume ; benzene of sp. gr. about 0.850, 3 vols.], boil them together for about half an hour, decant and drain oif the liquid on to a filter, leaving 'the powder in the flask ; add more of the benzolated amyl alcohol to the powder, and boil and de- cant as before ; repeat this operation a third time ; then turn the contents of the flask on to the filter, and wash by percolation with the benzolated amyl alcohol until the bark is exhausted. If during the boiling a funnel be placed in the mouth of the flask, and another flask filled with cold water be placed in the funnel, this will form a convenient condenser which will prevent the loss of more than a small quantity of the boiling liquid. Introduce the collected filtrate, while still warm, into a stoppered glass separator ; add to it 20 minims [1.1 c.c.] of diluted hydro- chloric acid [of 10.58$ real acid] mixed with 2 fluid-drachms [7 c.c.] of water; shake them well together, and when the acid liquid has separated this may be drawn off, and the process repeated with distilled water slightly acidulated with hydrochlo- ric acid, until the whole of the alkaloids have been removed. The acid liquid thus obtained will contain the alkaloids as hy- drochlorates, with excess of hydrochloric acid. It is to becare- fully and exactly neutralized with ammonia while warm, and then concentrated to the bulk of 3 fluid-drachms [about 10 c.c.] If now about 15 grains [0.972 gram] of tartarated soda [potas- sium sodium normal tartrate], dissolved in twice its weight of water, be added to the neutral hydrochlorates, and the mixture stirred with a glass rod, insoluble tartrates of quinine and cin- ch onidine will separate completely in about an hour ; and these collected on a filter, washed, and dried, will contain eight-tenths of their weight of the alkaloids, quinine and cinchonidine, which [in grains] divided by 2 [or in grams multiplied by 8] repre- sents the percentage of those alkaloids. The other alkaloids will be left in the mother-liquor." (2) For total alkaloids: "To the mother-liquor from the preceding process add solution of ammonia in slight excess. Collect, wash, and dry the precipi- tate, which will contain the other alkaloids. The weight of this precipitate [in grains] divided by 2 [or, in use of the mefcric no CINCHONA ALKALOIDS. quantities, its weight in grams multiplied by 8], and added to the percentage weight of the quinine and cinchonidine, gives the percentage of total alkaloids." 4. The use of alcohol to dissolve the free cinchona alkaloids, then obtained by precipitation from aqueous solution. 1 The di- rections of the U. S. Ph. are as follows : " for total alkaloids : Cinchona, in No. 80 powder, and fully dried at 100 C., 20 grams ; lime, 5 grains ; diluted sulphuric acid, solution of soda, alcohol, distilled water, each a sufficient quantity. Make the lime into a milk with 50 c.c. of distilled water, thoroughly mix therewith the cinchona, and dry the mixture completely at a temperature not above 80 C. (176 F.) Digest the dried mix- ture with 200 c.c. of alcohol, in a flask, near the temperature of boiling, for an hour. When cool pour the mixture upon a filter of about six inches (15 centimeters) diameter. Rinse the flask and wash the filter with 200 c.c. of alcohol, used in several portions, letting the filter drain after use of each portion. To the filtered liquid add enough diluted sulphuric acid to render the liquid acid to test-paper. Let any resulting precipitate (sulphate of calcium) subside ; then decant the liquid, in portions, upon a very small filter, and wash the residue and filter with small por- tions of alcohol. Distil or evaporate the filtrate to expel all the alcohol, cool, pass through a small filter, and wash the latter with distilled water slightly acidulated with diluted sulphuric acid, until the washings are no longer made turbid by solution of soda. [Alternative directions, from this point, given below '.] To the filtered liquid, concentrated to the volume of about 50 c.c., when nearly cool, add enough solution of soda to render it strongly alkaline. Collect the precipitate on a wetted filter, let it drain, and wash it with small portions of distilled water (using as little ~DE VBIJ, 1873: Phar. Jour Trans., [3], 4, 241; Proc. Am. Phar., 22, 268. U. S. Ph., 1880, p. 78. A. B. Prescott in "Report on the Revision of the U. S. Ph.," New York, 1880, p. 26. This is a direct and simple method, in common use and giving good results. The precipitation and washing is open to the objection, elsewhere noted, that quinine thereby suffers a little loss. This is avoided in the alternative, modifica- tion by shaking out the total alkaloids with chloroform, given here from the Report on Revision." &CEBEL (1884: Proc. Am. Phar., 32, 474) proposes, very properly, the adap- tation of the process to the plan of taking an aliquot part of the alcoholic solu- tion, as in Prollius's method, as follows: " Place 15 grams of cinchona treated with milk of lime and perfectly dried in a flask, add 150 c.c. of alcohol, weigh the whole, digest the loosely stoppered flask and contents for about two hours at 150 to 160 F., cool, replace the slight loss of weight by alcohol, filter, through a covered filter, 100 c.c. equivalent to 10 grams of the bark, and proceed with this extraction practically as directed by the Pharmacopoeia." SEPARATION AND ESTIMATION. in as possible) until the washings give but a slight turbidity with test-solution of chloride of barium. Drain the filter by laying it upon blotting or filter papers until it is nearly dry. " Detach the precipitate carefully from the filter and transfer it to a weighed capsule, wash the filter with distilled water aci- dulated with diluted sulphuric acid, make the filtrate alka- line by solution of soda, and, if a precipitate result, wash it on a very small filter, let it drain well, and transfer it to the capsule. Dry the contents of the latter at 100 C. (212 F.) to a con- stant weight, cool it in a desiccator, and weigh. The number of grams multiplied by five ,(5) equals the percentage of total alkaloids in the cinchona." Alternative directions from point above noted : Concentrate the filtrate to the volume of 50 c.c. or less. Transfer, rinsing with a little water, to a glass separator of 100 to 150 c.c. ca- pacity. Add solution of soda in decided excess, then at once add 30 to 40 c.c. of chloroform, stopper, agitate for a few minutes, set aside for an hour or two, and draw off the clear chloroform layer. In the same way extract with three smaller portions of the chloroform, using in all at least 120 to 130 c.c. of this solvent. The chloroform is then recovered by distilla- tion or is slowly evaporated, the concentrated liquid is trans- ferred, with chloroform rinsing, to a weighed dish, and the re- sidue dried on the water-bath to a constant weight. The grams multiplied by 5 express the percentage of total alkaloids in the bark. 1 SEPARATION OF CINCHONA ALKALOIDS FROM EACH OTHER. I. SEPARATION OF QUININE. A. From other cinchona alkaloids in general* 1. By crystallization of the sulphate in aqueous solution (p. 113). 2. " crystallization of herapathite (under Quinine, /, "Hera- pathite " ). 3. " solution in ether (p. 116). 4. " solution in ammonia (see under Quinine, g, "Kerner's Test"). 1 "This I find," shaking out with 50 c.c. and then with three successive portions, each of 25 c.c. of chloroform, "will bring back invariably 5.99 out of 6.00 grams of pure mixed alkaloids, and is decidedly the most accurate method, given practice in the way of shaking, etc., so as to get the chloroform to settle quickly." J. MUTER, 1880: The Analyst, London, 5, 223. 2 There may be added, for trial, (5) separation by precipitation as Oxalate-^ Shimoyama, 1885: Arcfiiv d. Pliar., [8], 23, 209. Ii2 CINCHONA ALKALOIDS. B. From Cinchonidine. 1. By recrystallizations of the sulphate (p. 113). 2. " solution in ammonia, in filtrate from saturated sulphate (p. 117). C. From Quinidine. 1. By non-precipitation with potassium iodide (see Quinidine, /*). 2. " non-solution of the sulphate in chloroform. 1 3. " precipitation as normal tartrate. D. From Cinchonine. 1. By non-solution of the sulphate in chloroform. 1 2. " precipitation as neutral tartrate (compare " Separation of Cinchonidine," p. 118). E. From Amorphous Alkaloids. 1. By crystallization of the sulphate. II. SEPARATION OF CINCHONIDINE. A. From other cinchona alkaloids in general. 1. After removal of Quinine, by precipitation with normal tar- trate (p. 118). 2. By precipitation as tartrate, followed by removal from Qui- nine by I. A. 1, 2, 3, or 4. B. From Cinchonine and Quinidine. 1. By non- solution of the sulphate in chloroform. 2. " precipitation as neutral tartrate (p. 118). C. From Quinine. 1. By non-crystallization as sulphate, repeated (p. 113). 2. " solution in excess of ammonia after filtration of sulphate (p. 117). D. From Amorphous Alkaloids. 1. By crystallization as normal tartrate (p. 119). 1 Taken separately, quinine sulphate and Cinchonidine sulphate each re- quires about 1000 parts of chloroform for solution, while quinidine sulphate dissolves in 20 parts, and cinchonme sulphate in 60 parts, of this solvent. Taken in mixtures of quinine or Cinchonidine with quinidine or cinchonine, these differences of solubility are seriously diminished (the author with Mr. Thum, 1878: Proc. Am. Pharm., 26, 831). SEPARATION OF QUININE, n 3 III. SEPARATION OF CINCHONINE. A. From other cinchona alkaloids in general. 1. By non-solution in ether (p. 116). 2. " more sparing solution in alcohol. B. From Quinine. 1. By not crystallizing as sulphate (see below). 2. " solution of the sulphate in chloroform (see note on p. 11 2). C. From Cinchonidine. 1. By solution of the sulphate in chloroform. 2. " non-precipitation as neutral tartrate (p. 119). D. From Quinidine. 1. By non-precipitation with potassium iodide (Quinidine, e). E. From Amorphous Alkaloids. 1. By dilute alcohol. 2. " ether. SEPARATION OP QUININE (I. A, 1) from other cinchona alka- loids in general, by crystallization oj the sulphate in aqueous solution The solubilities of the sulphates of the four alkaloids in water at 15 C. (59 F.) is, respectively, quinine, 740 parts ; quinidine and cinchonidine, each 100 parts ; cinchonine, 70 parts. The comparative insolubility of quinine sulphate in cold water is the most trusty factor in Kerner's test for quinine, offi- cial in U. S. Ph., in Ph. Germ, since 1872, and in the Ph. Fran., 1884. 1 Sulphate insolubility also enters into the Br. Ph. test The insolubility of quinine sulphate is not materially affected by the presence of other cinchona alkaloidal sulphates, 8 which is, unfortunately, not true of the solubility of quinine in ether, or of the insolubility of quinine sulphate in chloroform. To effect complete separations, however, several recrystalliza- tions are necessary. Cinchonidine certainly opposes some resist ance to separation from quinine. HESSE has recently reaffirmed 3 that quinine sulphate is fully freed from as much as 2 per cent, of cinchonidine sulphate by two crystallizations from boiling water. 'KERNER, 1862: Zeitsch. anal. Chem., 1, 150; Phar. Jour. Trans., [2], 4, 19; Am. Jour. Phar., 34, 417. 1880: Archiv d. Phar., [3], 16, 186; 17,438; Jour. Chem. Soc., 40, 63. Kerner rests the separation in good part upon the action of ammonia in the filtrate. 2 The author and Mr. Thum, 1878: Proc. Am,. Pharm., 26, 834. " Report on 'Revision U. S. Ph.," 1880, pp. 29, 116. 3 HESSE, 1886: Phar. Jour. Trans., [3], 16, 818; (1885) [3], 15, 869. ii4 CINCHONA ALKALOIDS. DAVIES (1885) l found numerous recrjstallizations necessary to obtain a salt with constant rotatory power. KEENER (1880) a found that three to six crystallizations of commercial quinine sul- phate suffice to give a perfectly pure salt, as shown by a constant behavior in his ammonia titration. KERNEK (1880) further states that in crystallizing from hot watery solution a slightly basic salt is crystallized. In this case the cleaned crystals become slightly alkaline to test-paper, while the filtrate becomes acidu- lous to a corresponding degree. To effect the utmost separation by one crystallization it is in- dispensable to hold the reaction of the initial solution exactly neutral, as a slight acidity increases the solubility of quinine sul- phate. In separations for estimation, therefore, the reaction should be neutral. But in separation to prepare absolutely pure quinine salt, though at expense of partial loss, crystallization from acidulous solution is more efficient. DE YRIJ has advised to convert to the definite acid sulphate [by adding as much more sulphuric acid as the quantity required to convert the free alka- loids into neutral salts] ; then crystallize the acid salt, recrystal- lizing as necessary ; and finally form the normal salt by precipi- tating one-half as the hydrate, and dissolving the washed precipi- tate in solution of the remaining acid salt. The following directions for separation of quinine as sul- phate are in effect those of the II. S. Ph., 1880 (p. 79), a but with provision for better regulation of the use of acid and alkali, an increase of temperature in the digestion before crystallizing, and the drying to anhydrous instead of effloresced sulphate. The unchanged pharmacopoeial text is enclosed in quotation-marks. " To the total alkaloids from 20 grams of cinchona, previously weighed," or to a weighed quantity (0.5 to 5.0 grams) of any ordinary mixture of free cinchona alkaloids, taken in a weighed beaker of capacity of about 120 fluid parts for 1 part of alka- loids, add from a burette decinormal solution of sulphuric acid until the liquid is " just distinctly acid to litmus-paper " and re- tains this degree of acidity after 15 to 30 minutes' digestion on 'DAVIES, 1885: Phar. Jour. Trans., [3J, 16, 358. To same effect, OUDE- MANS, Jahr. Chem., 1876. It is surmised that a double sulphate of cinchoni- dine and quinine crystallizes, according to KOPPESCHAAR (1885) with 6H 2 0. See, also, YUNGFLEISCH, 1887: Phar. Jour. Trans. [3] 17, 585 2 KEENER, 1880: Archiv d. Phar., [3], 16, 191. As to the ammonia test, see under Quinine, g, "Kerner's test." Kerner found that heating the solution before the crystallizing at 15 C. had little influence on the result. 3 Given first in the author's contribution to "Report on Revision U. S. Ph.," 1880, p. 26. Data taken from the report of Prescott and Thum, 1878: Proc. Am. Pharm. , 26, 834. SEP A RA TION OF Q UININE. 1 1 5 the water-bath. 1 Add now decinormal solution of soda from the burette until after stirring the reaction is "exactly neutral to the test-paper." Note the number of c.c. of acid and of alkali which have been added. 3 Add water " to make the whole weigh seventy times 3 the weight of the alkaloids." Heat to near boil- ing for five or ten minutes, " then cool to 15 C. (59 F.) and maintain at this temperature for half an hour. If crystals do not appear the total alkaloids do not contain quinine in quantity over eight per cent, of their weight (corresponding to nine per cent, of sulphate of quinine, crystallized). If crystals appear in the liquid pass the latter through' a filter not larger than necessary, prepared by drying two filter-papers of two to three and a half inches (5 to 9 centimeters) diameter, trimming them to an equal weight, folding them separately, and placing one within the other so as to make a plain filter fourfold on each side. When the liquid has drained away wash the filter and contents with distilled water of a temperature of 15 C. (59 F.), added in small portions, until the entire filtered liquid weighs ninety times 4 the weight of the alkaloids taken. Dry the filter, with- out separating its folds," at 100 C., 6 " to a constant weight, cool, and weigh the inner filter and contents, taking the outer filter for a counter- weight. To the weight of" anhydrous sulphate of quinine so obtained add 16.89 per cent, of its amount for water of crystallization. 8 "And add 0.12 per cent, of the weight 7 of J If the alkaloids be contaminated with resin and kinic acid, add enough more of the volumetric acid to surely dissolve all the alkaloids, avoiding excess of acid, and filter through a filter as small as possible, washing with the least quantity of hot water and a few drops of acid from the burette, until a drop or two of the washings cease to react for quinine when tested with a drop of May- er's solution. To the filtrate add of decinormal solution of soda as many c.c. as have been added of the acid beyond the point of just perceptible acidity, bring- ing back the reaction to this point. 2 Then (c.c. of decinormal acid c.c. of alkali) X 0.03 [0.0324 to 0.0294]= nearly the quantity of total cinchona alkaloids present, in grams. But observe that if the alkaloids have been precipitated with soda, incomplete washing may have left behind sufficient alkali to affect the result. 3 Or to make the whole measure of c.c. a number equal to 2.1 X (c.c. of decinormal acid u.c. of alkali). 4 Or until the liquid measures, in c c., 2.7 times (c.c. of decinormal acid c.c. of alkali). 6 The U. S. Ph. directs to dry at 60 C. (140 F.) to a constant weight as effloresced sulphate (2H 2 0). Of this weight 11.5 per cent, is added to give the quantity of crystallized salt (7H 2 0). 6 To represent seven molecules, or 14.45 per cent, crystallization water. See under Quinine ( f). 7 That is, add 0'.0012 of weight of crystals for each c.c. of total filtrate. This correction presumes that the saturated solution (|- of the filtrate) shall carry in solution 0.135 per cent, of crystallized salt (1 to 740), and that the washings (f of the filtrate) shall hold 0.067 per cent, of cryst. salt, which is n6 CINCHONA ALKALOIDS. the entire filtered liquid (for solubility of the crystals at 15 C.) " The sum equals the quantity of quinine as crystallized sulphate in the mixed alkaloids taken. If from 20 grams of the bark, multiply by 5 to convert to percentage. Of the crystallized sul- phate (7H 2 O), 74.31 per cent, is anhydrous quinine. Separation of Quinine (I. A, 3) from other cinchona alka- loids by ether. The ether solubilities of the alkaloids taken- sepa- rately are for good ether very nearly as follows, at 15 C. : quinine in 25 parts of the ether, quinidine in 30 parts, ciiichonidine in 188 parts, and cinchonine in 371 parts of ether. The amorphous alkaloids of cinchona have in general a very considerable solu- bility in ether. Quinidine occurs in so small quantities that its solubility is not regarded. But the different factors of solubility above stated are not available for separation, because, as every analyst experiences, they do not hold true in mixtures of the alkaloids. Thus in a mixture of quinine and cinchonidine, qui- nine is less soluble and cinchonidine is more soluble in ether than when these alkaloids are taken separately. 1 Nevertheless, sepa- ration by ether has been in use by quinologists more than any other separation. An analyst of bark learns by the manufac- turer's results so to adjust the application of the ether that, for example, about as much of quinine will remain undissolved as there is of cinchonidine in solution. The use of ether in testing quinine for presence of cinchonine is credited to LIEBIG 2 in the test which bears his name. For use of ether in the assay of the mixed alkaloids for quinine, or for ether-soluble alkaloids, the author prefers the very practical directions of Dr. SQUIBB, w r ho prefaces the following instructions 3 by the statement that " it half saturation. The degree of partial saturation of the washings (if held at 15 C.) is subject to the rate of application of the wash-water and its retention in the filter. Six experiments of the author with Mr. Thum (1878: Proc. Am. Pharm., 26, 834) gave a mean result equivalent to 0.00095 of crystallized sul- phate for each c.c. of filtrate (stated as O.C0085 of effloresced sulphate for each c.c.) The exact average figures as 0.00081 of effloresced salt for each c.c J. MUTER (1880: Analyst. 5, 224) adds 0.000817 of crystallized sulphate for each c.c. of total filtrate,' a filtrate which is about 80 per cent, saturated solution and 20 per cent, washings. Further evidence on the rate of this correction is desira- ble. The 0.12 per cent, correction may be too large. It is stated by CARLES (1872) that the solubility of the quinine sulphate is diminished by presence of ammonium sulphate; by SCHLICKUM (1885) that it is greatly diminished by pre- sence of sodium sulphate. But these facts seem to afford no aid in separation of clean sulphate of quinine for weight, unless by a resort to washing with saturated solution of quinine sulphate and a correction proportional to the drying-loss. Experimental results are given by PAUL, 1877. KOPPESCHAAR (1885: Zeits. anal. Chem., 24, 362) infers that quinine and cinchonidine unite in a compound which is readily soluble in ether. 2 A note on the history of the test is given under Quinine, g. '1882: Ephemeris, i* 111. SEPARATION OF QUININE. 117 seems only practicable, in a general way, to reach near approxi- mations by some method which is simple and easy of applica- tion " : " Into the flask containing the total alkaloids [from 5 grams bark, or 10 grams if poor in alkaloids], after these have been weighed, put first 5 grams of glass which has been ground up in a mortar to a mixture of coarse and fine powder, and then 5 c.c. of stronger ether (sp. gr. not above 0.725 at 15 C.) Cork the flask and shake it vigorously until by means of the glass all the alkaloids have been detached from the flask and ground up in the presence of the ether into fine particles. In this way the definite quantity of ether, which is large enough to dissolve all the quinine that could possibly be present, becomes entirely saturated with alkaloids in the proportion of their solubility, and the solution will necessarily embrace all the soluble ones as the quinine. Next mark two test-tubes at the capacity of 10 c.c. each, and place a funnel and a filter of 7 centimeters.(2.8 inches) diameter over one of them. Wet the filter well with ether, and then pour on to it the mixture of alkaloids, ether, and glass from the flask. Rinse the flask out two or three times on to the filter with fresh ether, and then wash the filter, and percolate the glass, with fresh ether, applied drop by drop from a pipette, until the liquid in the test-tube reaches the 10 c.c. mark. Then change the funnel to the other test-tube, and continue the washing and percolation with ether until the mark on the second test-tube is reached by the filtrate. Pour the contents of the two test-tubes into two small tared capsules, evaporate to a constant weight, and weigh them. The first capsule will contain what may be called the ether-soluble alkaloids. Subtract from the weight of these the weight of the residue in the second capsule, and the re- mainder will be the approximate weight of the quinine extracted from the 5 grams of bark." These weights multiplied by 20 will give the percentage of ether-soluble alkaloids and of quinine." It is here understood that the terms " ether-soluble alkaloids " and u quinine " have a conventional meaning. And the conclusion is adopted that the quinine is all or nearly all obtained in the first 10 c.c. of filtrate, while of the less soluble alkaloids nearly equal quantities are obtained in the first and the second 10 c.c. of nitrates. Therefore the subtraction of the weight of the second residue from the weight of the first will give an approxima- tion to the weight of the quinine. Separation of Quinine (I. A, 4) from other cinchona alka- loids by solution in excess of ammonia, after crystallization of the sulphate. An (uhtptation of Kernels volumetric method. ii8 CINCHONA ALKALOIDS. More fully studied for Cinchonidine than for quinidine or cin- chonine. 1 Application to a Precipitate or Residue of Qui- nine with small proportions of Cinchonidine (I. B, 2). The precipitate or residue is dried finally on the water-bath to a constant weight, and a weighed quantity, from 3 to 5 grams, of the dried alkaloids is taken. The alkaloids are treated with warm dilute sulphuric acid added with a little hot water to make the reaction just distinctly acidulous to litmus-paper, and retain this reaction after the alkaloids have been thoroughly saturated, when the mixture is exactly neutralized by adding dilute am- monia-water, and made up at temperature near 100 C. to a number of c.c. equal to 14.5 times the number of grains of dried alkaloid taken. The container is now placed in a bucket of water at about 15 C., along with a bottle of Standard Quinine Sulphate Solution (see Index) and a bottle of ammonia- water of sp. gr. 0.920, and the same temperature maintained for an hour or more, and adjusted at 15 C. near the close of this time. The two alkaloidal solutions are now filtered through dry filters, and the filtrates received in portions of 10 c.c. each, in test-tubes the standard quinine filtrates on one side, and the filtrates from the alkaloids to be estimated on the other side. The filtrates are titrated, in repeated trials, by adding ammonia from a burette (registering ^ c c.), until, on gently inclining or rotating the test- tube while it is closed by the finger, the precipitate at first formed is just redissolved. Should the first 10 c.c. of filtrate under estimation require more than about 4.8 c.c. of the ammonia (0.920), after deducting the c.c. taken for 10 c.c. of the standard quinine, then a 10 c.c. filtrate under estimation should be diluted, by addition of the standard quinine filtrate, to 2, 3, or 4 times the 10 c.c. volume (20, 30, or 40 c.c.), and portions of 10 c.c. of this di- luted filtrate tested. The results of these tests, after deducting the average c.c. of ammonia for 10 c.c. of standard quinine filtrate, are multiplied by 2, 3, or 4, to give the proper quantity of am- monia for 10 c.c. of the filtrate under estimation Taking now the mean of the several titrations for 10 c.c. filtrate under esti- mation, after deducting the mean of titrations of standard qui- nine filtrate, each 0.32 c.c. = 0.1 per cent, cinchonidine in the mixed alkaloids estimated. SEPARATION OF CINCHONIDINE (II. A, 1) from other cinchona alkaloids in general, after removal of quinine, ly precipitation 1 KEENER, 1862. Improved in 1880: Zeitsch. anal. Chem., 20, 150; Archie d. Phar., [8], 16, 186-285; 17. 488-454; Jour. Chem. Soc., 40, 63. Discussion, in this work, under Quinine, g. " Kerner's Test." SEPARATION OF CINCHONIDINE. 119 with normal tartrate. The quinine may be removed (1) by crystallization as a sulphate (p. 114), or (2) by solution in ether (p. 116). For the purpose of an estimation, a deduction of the quantity of quinine from the quantity of both quinine and cin- chonidine is quite sufficient. To this end the following direc- tions of MUTER, 1 here slightly varied, serve well: The quinine is separated and estimated as crystalline sulphate (p. 114), A weighed portion of the mixed cinchona alkaloids is dissolved with hydrochloric acid enough to make the solution only slightly acid 2 to test-paper, and as concentrated as compa- tible with solution at 38 C. (or 100 F.) 3 The solution is made exactly neutral by adding sodium hydrate dilute solution, an ex- cess of the precipitant, a saturated solution of tartrate of potas- sium and sodium (Rochelle salt) is added, and the mixture kept at 15 C. (59 F.) for an hour, stirring frequently with a glass rod. The precipitate is collected on a pair of niters as small as practicable and previously (dried and) counterbalanced with each other, and is washed with, say, 100 c.c. of water at 15 C., the iiltrate and wash- ings being received in a graduated measure. The precipitate is dried at 104 C. (or at 220 F.) and weighed, using the outer filter as a tare. For each c.c. of the total filtrate 0.00083 is added (MUTER) to the weight of the precipitate. The weight of anhydrous quinine sulphate is multiplied by 0.9151, or the weight of anhydrous quinine is multiplied by 1.231, to obtain the weight of anhydrous quinine tartrate, which is deducted from the weight of the precipitate. The remainder is the weight of anhydrous cinchonidine tartrate (C 19 H 22 N 2 ()) 2 C 4 H 6 O 6 , which, multiplied by 0.7967, gives the weight of cinchonidine. (For following separation of remaining' alkaloids see p. 120). /Separation of Cinchonidine (II. A, 2) by precipitation as tartrate, followed by removal from Quinine. This plan differs from the preceding only in the order of the successive steps. - In precipitating first as tartrate, in case of Commercial Quinine Sulphate, DE V KIJ (1884) directs to take 5 grams of the salt, in 200 c.c. boiling water, and add 5 grams of Rochelle salt previously dissolved in very little boiling water. After 24 hours collect on a filter, wash with the smallest quantity of water, and dry in the '1880: Analyst, 5, 224. 2 Muter dissolves the mixed alkaloids in absolute alcohol, divides in two equal portions, taking one portion for quinine as a sulphate. The portion for cinchonidine is made just acid with hydrochloric acid, the alcohol evaporated off, and the residue dissolved in least quantity of water at 100 F. 3 If the total alkaloids contain resins, kinic acid, etc , filter through a small filter, wash with as little dilution as possible, and if necessary concen- trate. 120 CINCHONA ALKALOIDS. air. KOPP states that a double normal tartrate of quinine and cinchonidine crystallizes with 1 molecule of water. HEILBIG (1880), following De Vrij, separates cinchona alkaloids in gene- ral, by initial precipitation of tartrates, as follows : 2 grams of the mixed alkaloids are dissolved as acetates in 30 c.c. of water, and the solution mixed with 1 gram Rochelle salt and well stirred. The precipitate is washed with care to avoid its solution, and dissolved in 90 per cent, alcohol acidulated with 1.6 per cent, of sulphuric acid, and herapathite is formed (as directed under Quinine, /'). The filtrate is treated with potassium iodide for precipitation of quinidine. The filtrate from the latter is treated with soda, and the resulting precipitate, dried, is exhausted by absolute ether for removal of amorphous alkaloids, the remainder being cinchonine. For separation of Cinchonidine, Quinidine, Cinchonine, and Amorphous Alkaloids from each other, after the estima- tion of Quinine, the directions of DE VKIJ are as follows : " Two Srams of the pulverized mixed alkaloids are dissolved in weak ydrochloric acid to obtain a slightly alkaline solution measur- ing TO c.c. By adding 1 gram of Rochelle salt to this solution," heating, cooling, stirring, and setting aside, as above indicated, " the tartrates of quinine and cinchonidine are separated ; these are collected on a filter, washed with a little water, and dried on a water-bath. One part of these tartrates represents 0.80844 of quinine and cinchonidine : from the amount of these alkaloids thus found the amount of quinine already ascertained is sub- tracted, the remainder representing the cinchonidine present." " In the filtrates from the tartrates, quinidine, if present, is pre- cipitated by a concentrated solution of potassium iodide [compare under Quinidine, d and f] ; one part of the dried hydriodide re- presents 0.86504 part of crystallized quinidine [0.7175 part of anhydrous quinidine]." " The remaining solution is treated with caustic soda, and the precipitate (if any) washed with ether. The residue represents the amount of cinchonine (compare under Cin- chonine, /")." " Finally, by distilling the ether from the wash- ings can be ascertained the amount of amorphous alkaloid, which often, in the case of analysis of Indian barks, contains traces of quinamine." The directions of J. MUTER/ for separation of Quinidine, Cinchonine, and Amorphous Alkaloid, taking the filtrate from Cinchonidine and Quinine tartrates (see p. 119), are as follows: " The filtrate from the tartrate is concentrated to its original 1 1880 : Analyst, 5, 224. ROTATORY POWER. 121 volume [that before the washing of the precipitate is probably intended], cooled, rendered just faintly acid by a drop of dilute acetic acid, and excess of saturated solution of potassium iodide is added with constant stirring. After an hour or so at 15 C. [compare under Quinidine, f] it is collected like the cinchoni- dine, and treated in every respect the same, and weighed, and the weight, having had 0.00077 added for each c c. of liltrate and washings, is multiplied by [0.7175], and result is quinidine" " The filtrate from the quinidine is made distinctly alkaline by sodium hydrate, and the precipitated cinchonine and amorphous alkaloid are filtered out in a similar manner, washed, dried, and weighed. The precipitate is then treated with alcohol of 40 per cent, to dissolve out the amorphous alkaloid, and again dried and weighed, and the difference is amorphous alkaloid, while the last weighing is cinchonine." But u the weight of the cincho- nine and amorphous alkaloid together must have deducted from it 0.00052 for each c.c. of the filtrate from the quinidine hydrio- dide, and 0.00066 for each c.c. of the filtrate from the cinchoni- dine tartrate, and the balance is then the true weight, which, minus the amorphous alkaloid, gives the cinchonine." ROTATORY POWER OF CINCHONA ALKALOIDS. The plane of polarized light is deviated to the left by quinine and cinchonidine, to the right by quinidine and cinchonine. Further, the dextrorotatory alkaloids include diquinicine, quini- ] D=-(107.48 0.297C) " Cinchonidine sulphate, 6 aq., in water, (c=1.06), 15 C., [a] D= 106.77 " Cinchonidine sulphate, anhyd., in 2.156$ sol. in alcohol, [a] D= 153.95 " "With 0.40 gram of the salt, with 3 c.c. normal solution hy- drochloric acid, and water to make a volume of 20 c.c (" Con- centration A " of Oudemans) : Quinine tartrate, cryst., [a] D= 215.8 OUDEMANS. Anhyd.= 220, 07 KOPPESCHAAR. Cinchonidine tart., cryst., [a] D= 131.3. . . . OUDEMANS. Anhyd. =137.67 KOPPESCHAAR. Take 0.40 of mixed tartrates of quinine and Cinchonidine (see under Separation of Cinchona Alkaloids by Tartrate, p. 119), dry at 125 to 130 C., dissolve as stated above for " Concentra- tion A," observe rotatory power (a), then, to find x =. per cent, of quinine tartrate in the mixed tartrates : 220. 07 a* + 137.67 (100-0?) = 100 a. 100 (a 137.67) , And ^220.07-137.67' For the estimation of cinchonidine in commercial quinine KOPPESCHAAR, 1885: Zeits"h. anal. Chem., 24, 362; Jour. Chem. /Sloe., 49, 182. OUDEMANS, 1875: Arch, neerland. des Sci., 10, 193; Jahr. Chem., 1875, 140. Further, 1877 and 1884. RO TA TOR Y PO WER. 123 sulphate HESSE l directs as follows : 2 grams of anhydrous com- mercial quinine sulphate, or an equivalent quantity of crystallized salts, are weighed in a flask of 25 c.c. capacity, mixed with 10 c.c. of normal solution of hydrochloric acid, the flask filled up to the graduation-mark with water, and, after the contents are thoroughly mixed by shaking, the solution is poured through a filter into the observation -tube, which is 220 millimeters long and is provided with a water-jacket for maintaining a constant temperature. From 12 to 20 observations are made with this solution, at 15 C., and' the mean of the different readings is taken. Let c = the observed deviation at the D line, and y == the cinchonidine sulphate. 3 Then, if the observation-tube be 220 m.m., y= (40.309 G) X 8.25. For other lengths of the observation-tube let C = the observed rotatory power, when y = (229.03 C) X 1.452. Quinidine, deviation diminishes with elevation of temperature. Quinidine hydrate, in alcohol of 97$ vol., at 15 C., [a] D=+(236.77-3.01c) HESSE. Quinidine anhyd., in alcohol of 97$ vol., at 15 C., [a] D =+(269.57-3.428c) Quinidine hydrochloride, in alcohol of 97$, at 15 C., [a] D=+(212-2.562c) Cinchonine, in alcohol, c=0.455, [a] D=+214r.8 c=0.535, = 213.3 c=0.560, = 209.6 OUDEMANS. Cinchonine sulphate, in water, c = 0.855, [a] D= +170 HESSE. Cinchonine sulphate, in 97$ alcohol, c = 0.374, [a] D = +193.29 Cinchonine hydrochloride, [a] D=+(165 2.425c).. " Quinicine, in 97$ alcohol with chloroform, [a] D +(10.68 1.14c). Cinchonicine, in chloroform, at 15 C., [a] D=+46.5. 1 1880: LieUg's Annalen. 205, 217; Jour. Chem. Soc., 40, 315. Also, 1885: Phar. Jour. Trans., [3]. 15, 869. 2 If a be the angle of rotation of dry quinine sulphate, b tht angle of anhy- drous cinchonidine sulphate, and c the angle of the mixture, then if x be the quantity of quinine sulphate, and y the quantity of cinchonidine sulphate, the relative percentage of the last-named salt is expressed by the formula y = ?. For a and b Hesse has found the numbers 40.309 and 26.598; there- 40 309 c fore y = ^ , or, taking y as percentage, y = (40.309 c) 7.293. On ac- count of the common efflorescence of cinchonidine sulphate, Hesse modifies the formula to ?/ = (40.309 c) 8.25. 124 CINCHONA ALKALOIDS. A single determination in a given solvent obviously cannot be used for estimation when more than two alkaloids of cinchona are present. But by use of different solvents, or different tem- peratures and concentrations, it has been proposed to undertake estimation in mixtures of three alkaloids. OUDEMANS has stated that optical estimation is practicable in the following-named mix- tures : quinine and cinchonidine ; quinine and quinidine ; quini- dine and cinchonidine ; quinine and cinchonine ; cinchonidine and cinchonine ; quinine, quinidine, and cinchonidine ; quinine, quinidine, and cinchonine ; quinidine, cinchonidine. and cinclio- nine ; quinine, cinchonidine, and cinchonine ; and tartrate of quinine, and cinchonidine. KOPPESCHAAR * has advocated the su- perior efficiency of the optical way of estimating cinchona alka- loids, and DAviES, 2 in report of the extended research already cited, expresses confidence in the optical estimation of cinchoni dine in commercial quinine sulphate. HESSE, who engaged ex- tensively in optical researches upon the cinchona alkaloids in 1875, 3 and published an optical method of valuation of quinine sulphate in 1880, 4 in 1886 5 admits a diminished confidence in the optical method for exact estimations, and says that " up to the present moment we are not in possession of any optical test by which we would be able to determine the amount of cinchoni- dine in commercial quinine sulphate and other quinine salts with any satisfactory degree of accuracy." And '' while constant rota- tory power in two successive recrystallizations of the same mate- rial [quinine sulphate] is satisfactory evidence of absence of cin- chonidine in that particular material, it is not by any means the case that the rotatory power of similar materials of different ori- gin is always the same." PATTI/ has stated "that the results by the polariscope are much less trustworthy than those by other methods." KERNER T holds it to be manifestly impracticable to determine proportions of 1 and \\ per cent, of cinchonidine sul- phate, in mixtures of quinine sulphate, with even minute propor- tions of cinchouine and quinidine sulphates. The influence of hydroquinine salt, in the optical valuation of quinine sulphate, is emphasized by HESSE in the communication '1885: Phar. Jour. Trans., [3], 15, 809. 8 1885: Phar. Jour. Trans., [3], 16, 358. *Liebig's Annalen, 176, 203-233. . 4 Liebitfs Annalen, 205 , 21 7-222 6 Phar. Jour. Trans., [3], 16, 818, March 27, 1886. Further, same journal, June 5, 1886. 8 1885: Phar. Jour. Trans., [3], 16, 361. 7 1880: Archiv d. Phar., [3], 16, 449. QUININE. 125, last above cited from this author. 1 He places the rotatory power of the three alkaloids chiefly concerned in. the estimation of com- mercial quinine sulphate as follows. The conditions of OCDE- MANS (p. 122) are adopted : For concentration A : Quinine tartrate (a) D = 216.6 Cinchonidine tartrate 134.6 For concentration B : Quinine tartrate 212.5 Hydroquinine tartrate 176.9 Cinchonidine tartrate 132.0 Oudemans's own results w.ere (see p. 122) : For concentration A : Quinine tartrate (a) D = 215.8 Cinchonidine tartrate 131.3 For concentration B : Quinine tartrate 211.5 Cinchonidine tartrate 129.6 QUININE. Chinin. C 20 H 24 :N" 2 O 2 =324. Crystals of full hy- dration, C 20 H 24 N 2 O 3 .3H 2 O=:378. ~ Kational Formula, p. 98. Proportion in Cinchona Barks, p. 96. Accompanying Natural Alkaloids, p. 90. Methods of quantitative separation from Cin- chona Bark, p. 102 ; from other Cinchona Alkaloids, p. 113. Means of Distinction from other Cinchona Alkaloids, schedule, p. 100. Microscopic identification, p. 101. Optical Rotation^ p. 121. Crystallization and Heat-Reactions of the free alkaloid and its salts, p. 126. Solubilities of the alkaloid and of its salts,, p. 128. Physiological effects, p. 127. Quinine is recognized by the fluorescence of its sulphate solu- tion (d\ its bitterness (J), and the sparing solubility of its sul- phate in water (c). It is identified, further, by the thalleioquin test, the agreement of various reactions, and 'the formation of herapathite (d). The separation of quinine from other cinchona alkaloids is indexed at p. Ill ; from the bark, given on pp. 102 to 111 ; from impurities of its commercial salts, and from various common alkaloids, also from Citrate of Iron, and from Coated Pills, page 134. Means of separation are noted under e. Quinine is estimated, as stated under g, by weight of the free alkaloid, by weight of the sulphate, by weight of the iodomer- curate, by titration with Mayer's solution, and by weight of crys- tallized herapathite. The impurities and deficiencies of quinine 1 For a brief summary of the claims of De Vrij and Hesse see Am. Jour. Phar., 1886, Aug., 58, 38J9, editorial. Respecting optical estimations of qui- nine, treating the tart-rates of the alkaloids, a paper is presented by D. HOOPER Ootacumund, India, 1886: Phar. Jour. Trans., [3], 17, 61. 126 CINCHONA ALKALOIDS. salts (under g) are chiefly the other cinchona alkaloids, and varied quantities of water. The other cinchona alkaloids are subject to test by Kerner's method, qualitative or quantitative, and given for salts other than sulphate, the free alkaloid, the bisulphate, and for effloresced salts. Tests are given by Hesse's method, and by the directions of the pharmacopoeias of the dif- ferent nations. Concerning Liebig's test, and standards of water of crystallization, a full discussion is included under g. a. Free quinine usually appears in an amorphous or curdy or minutely crystalline white powder, or in crystals slightly efflo- resced. The trihydrate (3H 2 O) forms needles, sometimes long and silky. Crystallizing under the microscope, four- sided prisms are obtained. The precipitate by alkalies from aqueous solution of quinine salts is at first amorphous and anhydrous, but gradu- ally assumes crystallization as the trihydrate. From warm, dilute alcoholic solution anhydrous crystals have been obtained (HESSE, 18TT). From ether, and most solvents other than water and alco- hol, crystals are never obtained. A dihydrate (2H 2 O) and a crys- tallizable monohydrate (H 2 O) have been reported ; also an amor- phous hydrate with 9H 2 O. The precipitate by ammonia, dried in the air at ordinary temperature, and the residue from solution in ether dried in the same way or over sulphuric acid, retain one molecule of water (FLETCHER, 1886). The trihydrate, nearly permanent in the air, loses all but about one molecule of the water slowly in the desiccator, quickly on the water-bath. All hydrates lose water gradually in warm temperatures, and on the water-bath quickly lose all but four or five per cent, (about one molecule) of the water, which is very slowly expelled (A. N. PALMER, 1876). At about 120 C. (248 F.) a constant weight of anhydrous alkaloid is promptly obtained. The trihydrate melts at 57 C. (134.6 F.) ; the anhydrous alkaloid melts, without loss, at 177 C. (350.6 F.) (HESSE, 1877), cooling to an opaque, crystalline mass permanent in the air. Strongly heated above the melting point, an amorphous, not crystalline sublimate is obtained. Crystallization and heat-reactions of salts of quinine. 1 Quinine sulphate forms fragile, filiform crystals on the mono- clinic system, with 7H O (KERNER, 1880) or 8H 2 O (HESSE, 1880). (See " Water of Crystallization," etc., under g.) The crystals are efflorescent. The hydration is reduced, slowly in ordinary air, promptly at 50 to 60 C., to 2H 2 O. The remain- ing water is expelled slowly at 100 C., or, by three hours' dry- 'For chemical formulae see " Solubilities," p. 129. QUININE. 127 ing in a water-oven (H. B. PARSONS, 1884), more quickly at 112 to 115 C. The anhydrous salt recovers the 2H 2 O by exposure to the air. At or above 100 C. the salt soon begins to suffer alteration ; at about 160 C. it exhibits a greenish phosphor- escence, and above this temperature it melts, with conversion into quinicihe sulphate, but without loss of weight. The salt is very slowly affected by the light. On ignition it burns very slowly, leaving no residue after complete combustion. Quinine bisulphate forms orthorhombic four- sided prisms, or needles, sometimes nodular crystals (7H 2 O), efflorescing in the air, more rapidly in warm air, to 1H 2 O, and becoming anhydrous at 100 C. It melts in a glass tube at 80 C. (Ph. Germ.) When anhydrous it melts at or below 100 C. "At 135 C. (275 F.) it is con- verted into bisulphate of quinicine " (U. S. Ph.), this conversion beginning at the melting point, also by exposure to sunlight, and being attended with a yellowish tinge. There is a doubly acid salt, crystallizable, with 7H 2 O, in prisms. Quinine liydrobro- mide crystallizes in lustrous needles (H 2 O), " permanent in the air but readily efflorescing at a gentle~heat" (IT. S. Ph.), and becomes anhydrous on the water-bath. Quinine hydriodide, normal, is crystallizable in light yellow needles, instable, easily altered to a soft, resinous mass. Quinine nitrate crystallizes with difficulty in very oblique prisms (H 2 O), easily melted to an oily mass, and becoming anhydrous at 100 C. Quinine val- erianate crystallizes in pearly, triclinic crystals (H 2 O), perma- nent in the air, melting at about 90 C., becoming anhydrous at 100 C., at which temperature it also begins to lose valerianic acid. Quinine normal tartrate, H 2 O, becomes anhydrous at 100 C. Quinine oxalate, normal, crystallizes with 6H 2 O, in very fine needles. J. Quinine is odorless, and has a pure bitter taste of much intensity. The persistence and intensity of the bitter taste of quinine salts is in proportion to their solubility as brought in contact with the tongue. Of ordinary forms administered the tannate is the least and the free alkaloid next least bitter, the sulphate being less bitter than the bisulphate, hydrobromide, or hydrochloride. Quinine is poisonous to the lower forms of ani- inal life, in this effect being surpassed among vegetable poisons only by such as strychnine and morphine (BiNz). For frogs the fatal dose is 0.05 to 0.1 gram (f to 1| grain) internally, or about 0.0025 (| grain) subcutaneously. For dogs about "0.12 gram per kilogram (-J grain per pound) of body-weight proves fatal 1867). Infusoria and bacteria are destroyed with 128 CINCHONA ALKALOIDS. somewhat concentrated solutions of quinine salts, quite variable strengths being required for different infusoria. Quinine is antiseptic, hindering or stopping the alcoholic, lactous, butyrous, amygdalous, and salicylous fermentations (BiNZ, u Husemann's Pflanzenstoffe," 1884), not the digestive action of pepsin. Qui- nine is excreted in the urine to the extent of 70 to 96 per cent, of the amount taken. It appears in the urine as early, fre- quently, as one hour, and usually disappears as soon as forty- eight hours, after ingestion (KEENER, JURGENSEN, and FRAU). Quinine is found in the liver. In some small part, also, it suf- fers conversion in the system into amorphous quinine [di- quinicine?], and an oxidation product, Dihydroxyl-quinine (C 20 H 24 N 2 O 4 ) (KERNER), or, according to SKRAUP, Chitenine (C 19 H 22 N 2 O 4 ). Kerner states that the physiological action of the oxidized product is much weaker than that of quinine. Chi- tenine is formed by action of permanganate on quinine, is insolu- ble in ether, fluoresces, and gives the thalleioquin reaction. c. Solubilities. Quinine is sparingly soluble in water ; quite freely soluble in alcohol, ether, chloroform, amyl alcohol ; mode- rately soluble in water of ammonia, benzene, glycerine ; and sparingly soluble in petroleum benzin. The alkaloid trihydrate is soluble in 1670 parts water at 15 C. (HESSE), in 1428 parts water at 20 C. (SESTINI, 1867), in 760 parts boiling water (REG- NAULD, 1875), in 902 parts boiling water (SESTINI), in six parts of ordinary alcohol at 15 C., in ly 1 ^ parts absolute alcohol (REG- NAULD), in 2 parts boiling alcohol of 90$, in " about 25 parts of ether" (U. S. Ph.), in 22 parts of ether at 15 C. (REGNAULD), in u about 5 parts of chloroform" (U. S. Ph.) The anhydrous alkaloid is soluble in 1960 parts of water at 15 C. (HESSE), in about the same proportion of ether required for the hydrate (HESSE), in (near) 2 parts chloroform (PETTENKOFER, 1858), in 200 parts benzene at 15 C. or 30 parts boiling benzene (OuDE- MANS, 1874). Crystals, mostly needle-form, can be obtained from nearly all solutions. From benzene, crystals of C 20 H 24 N 2 O 2 +C 6 H 6 are obtained (OUDEMANS). Solubility in ether is diminished by pre- sence of other cinchona alkaloids (PAUL, 1877). Quinine has a decided alkaline reaction, promptly shown upon test-papers in the aqueous solution. The normal salts of the stronger acids are neutral to litmus, the sulphate of manufacture not'infrequently alkaline in the least perceptible degree. Quinine salts of ordinary acids are soluble or moderately soluble in water and in alcohol, except the sulphate, which is only sparingly soluble QUININE. 129 in water. The proportion of water required for the free alkaloid at 100 C. is about that required for the sulphate at 15 C. Solubilities of quinine salts. Quinine sulphate, (C 00 H 24 :N^O 2 ) 9 H Q SO 4 .7H 2 O:=S72, is soluble " in 740 parts of water and in 65 parts of alcohol at 15 C. (59 F.) ; in about 30 parts of boiling water, in about 3 parts of boiling alcohol, in small proportions of acidulated water, in 40 parts of glycerine, in 1000 parts of chloroform, and very slightly soluble in ether " (U. S. Ph.) Its solubility in water is decreased by presence of am- monium sulphate (CABLES) or sodium sulphate (SCHLICKUM, 1885) ; in chloroform is increased by presence of cinchonine or quinidine sulphate. From acidulous aqueous solution it is sparingly dis- solved by amyl alcohol (BAKFOED). In alcoholic solution it is pre- cipitated by adding ether. Quinine bisulphate, C 20 H 24 N 2 O 2 H 2 SO 4 .7H 2 O=i548, is soluble "in about 10 parts of water (with vivid blue fluorescence) and in 32 parts of alcohol, at 15 C. (59 F. ) ; very soluble in boiling water and in boiling alcohol ?> (U. S. Ph.) It has a strongly acid reaction. The doubly acid sulphate, C 20 H 24 N 2 O 2 (H 2 SO 4 ) 2 7H 2 O, is freely soluble in water and in alcohol. Quinine hydrobromide, C 20 H 24 N 2 O 2 HBr . H 2 O =422.8, is soluble " in about 16 parts of water and in 3 parts of alcohol, at 15 C. (59 F.) ; in 1 part of boiling water and less than 1 part of boiling alcohol ; in 6 parts of ether, in 12 parts of chloroform, and moderately soluble in glycerine" (U. 8. Ph.) Quinine hydrochloride (muriate), C 22 H 24 N 2 O 2 HC1.H 2 O=378.4, is soluble " in 34 parts of water, and in 3 parts of alcohol, at 15 C. (59 F.) ; in 1 part of boiling water and very soluble in boiling alcohol ; when rendered anhydrous it is soluble in 1 part of chloroform " (U. S. Ph.) In 9 parts of chloroform (Hager's " Commentar " ). Normal quinine hydriodide, in stable, is more soluble than the sulphate. Quinine valerianate, C 20 H 24 N 2 O 2 C 5 H 10 O 2 . H 2 O=444, is soluble in about 100 parts of ~water and in 5 parts of alcohol, at 15 C. (59 F.), ... and slightly soluble in ether " (U. S. Ph.) Quinine tannate* amorphous, is but very little soluble in cold water (nearly tasteless), but is soluble in alcohol and slightly soluble in ether, and by long digestion with water is converted into soluble quinine gallate (LINTNER). Qui- nine tartrate, normal (C 20 H 24 N 2 O 2 ) 2 C 4 H 6 O 6 . H 2 O, is soluble in 910 parts of water at 10 C., much more soluble in hot water and in alcohol (HESSE, 1865). Quinine oxalate, (C 20 H 22 ]S" 2 O 2 ) 2 1 JOBST, 1878. Fluckiger's " Phar. Chemie," 425. Hager's " Phar. Praxis," iii. 291 . Produced of very variable composition and properties. A scribed formula, CaoH24N Q 02(Ui4Hio09J3=25 per cent, quinine. Jobst prepared it, 31 percent, quinine; and found it in commerce from 7 per cent, to 22 per cent, quinine. 130 CINCHONA ALKALOIDS. H 2 C 2 O 4 .6H O, requires 898 parts of water at 10 C. for solu- tion ; 1446 parts at 18 C. (SHIMOYAMA, 1885). d. Fluorescence. In general, quinine salts with inorganic acids containing oxygen exhibit blue fluorescence in their aqueous solutions. The hydracids of chlorine, bromine, etc. , the cyanogen hydracids, and thiosulphuric acid, in union with quinine, do not give fluorescence. By adding sulphuric acid the fluorescence is obtained with all the salts in aqueous solution. But the hydra- cids, if present, in proportion to their quantity diminish the reac- tion. Alcoholic solutions show little fluorescence ; solutions in ether, chloroform, etc., none at all. The bisulphate fluoresces much more strongly than the normal sulphate, in solutions of equal strength, and the fluorescence of a neutral solution of the sulphate is much intensified by acidulating with sulphuric acid. To obtain the full delicacy of the reaction, put the solution in a test-tube or beaker of such width that a depth of at least two inches is obtained. Place over a black ground, in a strong light falling horizontally from one direction, observing from above, comparing with a like column of distilled water, and, if neces- sary, shading the eye from the direct light and shading the liquid from the lateral light. Greater intensity is attained by throwing the light from a lens in a pencil upon the liquid. 1 So observed, 0.00005 gram quinine, in 5 c.c. acidulous solution, gives distinct fluorescence, and this (1 in 100000) is not the limit of dilution (BARFOED, 1881). The fluorescence of quinine is shared by qui- nidine, and by diquinicine, hydroquinine, hydroquinidine ; not by cinchonidine nor by quinicine. Thalleioquin test. Treated in a w^hite porcelain dish with fresh chlorine-water or bromine-water, not in too great excess, or well diluted, and then with ammonia to just effect an alka- line reaction, a solution of quinine gives a green precipitate, thalleioquin, dissolving to a green solution by adding a further excess of ammonia. In more dilute solutions a precipitate is not obtained at all, but a green liquid. Bromine gives with dilute solutions a better result than chlorine (ZELLER, 1880) ; an exces- sive action of either is to be avoided. According to BARFOED a fine reaction is given by 0.001 gram of quinine, in 5 c.c. of water acidulated with sulphuric acid, treated with 10 drops of very weak bromine- water or of fresh chlorine- water, and then with 2 drops of ammonia-water; but with 0.0005 gram, in 5 c.c., 2 drops 'For more minute examination see STOKES, 1853; H. Morton, 1871; " Watts's Diet.," 3, 634; 8, 1193. QUININE. 131 weak bromine -water and 1 drop ammonia- water, the limit is reached. TRIMBLE (1877) has used the reaction for a colorome- tric method, and prepared a standard green solution by propor- tions of 0.01 quinine or quinine salt in 5 c.c. of fresh chlorine - water, adding 10 c.c. of ammonia-water and diluting to 100 c.c. If the green ammoniacal solution be just neutralized with acid a blue tint is obtained, and, by acidulating, a violet to red color, returning to green again when ammonia is added in excess. If ferricyanide of potassium be added after the chlorine or bro- mine addition as above, and then ammonia barely enough for an alkaline reaction, a red color is obtained. Frcehde's reagent, with dry quinine, gives a slight green color (DRAGENDORFF). The thalleioquin test of quinine is shared by quinidine, diquini- cine, and quinicine, also by hydroquinine and hydroquinidine, but not by cinchonidine nor cinchonine. The alkali hydrates precipitate quinine from solutions of its salts, the precipitate becoming slowly crystalline (see #), and being quite readily soluble in excess of ammonia, and somewhat soluble in excess of ammonium carbonate, not of the fixed alkali hydrates, or only very slightly by potassa. Tartaric acid pre- vents the precipitation in solutions more dilute than about 1 to 300 ; and ammonium chloride increases the solubility of the pre- cipitate. In free ammonia the quinidine and cinchonidine pre- cipitates are less soluble than that of quinine, and the cinchonine precipitate is but very slightly soluble. The alkali carbonates, and, more slowly, the bicarbonates, precipitate quinine, insoluble or, with bicarbonates, but slightly soluble in excess. Herapathite test. Herapathite (HERAPATH, 1852) is one of the iodosulphates of quinine. Its formula (JORGENSEN, 1876) is (C ?0 H 24 lSr 2 2 ) 4 (H 2 S0 4 ) 3 (HI) 2 I 4 . (K 2 0\. Dried at 100 C., it contains 55.055 per cent, anhydrous quinine. It crystallizes in plates, either rectangular or rhombic, of six or eight sides. By reflected light the crystals are very lustrous, or iridescent emerald- green ; by transmitted light they are dichroic, in the direction of one axis nearly transparent, but when certain axes are super- imposed they are nearly opaque. A play of dark and light shades is obtained with crystals of microscopic size floating in a drop of liquid undeir the cover-glass. The large crystals have the optical powers of tourmalines, but in greater intensity. Herapathite is at first nearly insoluble in cold water and soluble in 1000 parts hot water, but is decomposed by water with formation of quinine bisulphate and hydriodide. It dissolves in 50 parts boiling alco- hol of 85$ by weight ; in 650 parts of cold alcohol of same 132 CINCHONA ALKALOIDS. strength. In 800 parts of 90$ alcohol at 16 C. (JORGENSEN). In 751 parts of 92$ alcohol at 245 C. (76.1 F.) (!)E YRIJ, 1875). It is always crystallized from alcohol, usually acidulated. The large crystals of herapathite can be mechanically separated from amorphous precipitate of other cinchona alkaloids. DE YRIJ states (1882) that the best reagent for the quali- tative recognition of crystallizable quinine, when in a mixture of cinchona alkaloids, is the iodosulphate of chinoidine, pre- pared as directed (under f) for quantitative uses. This is added to a solution of 1 part of cinchona alkaloids dissolved in 20 parts of 92-95$ alcohol acidulated with 1.5$ of sulphuric acid, this solution being then diluted with 50 parts of alcohol. The iodosulphate reagent is added (before heating) so long as a dark brown-red precipitate is formed, when, with slight excess of reagent, the liquid acquires a yellow color. The mixture is now heated to boiling, to dissolve the precipitate, then set aside for crystallization of the herapathite. BARFOED (1881) dissolves alka- loid supposed to contain 0.01 gram quinine in 20 drops, or 0.01 gram quinine sulphate in 10 drops, of a mixture of 25 drops of alcohol, 30 drops of acetic acid, and 1 drop of diluted sulphuric acid, heating to boiling, and then adding 2 drops of alcoholic solution of iodine (1 to 200) and setting aside. Crystallization may begin in 15 *to 30 minutes. Excess of iodine tends to produce other iodosulphates of quinine. JORGENSEN (1876) describes three classes of these : C 20 H 04 N 2 ) Q (H 2 S0 4 ) Olive-gray, bronze, brown, blue, and black colors are found, as well as green shades; and needles, as well as plates. The results are governed mainly by the proportions of quinine, io- dine, and sulphuric acid taken. The other cinchona alkaloids form iodosulphate precipitates, somewhat more soluble in alco- hol, and less crystallizable, than quinine iodosulphate. CHRISTEN- SEN (1881) states that cinchonidine, if present in at all large quantity, may be precipitated even by De Yrij's method with chinoidine. See also Cinchonine, d. Further citations from DE YRIJ are given under f, " Quantitative" p. 136. General reagents for alkaloids. Potassium mercuric iodide, or Mayer's solution, precipitates quinine in white flakes, appear- ing in acidulous solutions containing less than 1 part of the alka- loid in 100000 (f, p. 136). Phosphomolybdate throws down quinine from acidulous solutions, the yellow-white, curdy preci- QUININE. 133 pitate being almost absolutely insoluble. 1 Iodine in potassium iodide solution causes a reddish-brown precipitate. In solutions other than that of the sulphate the precipitate is at h'rst soft or amorphous ; in presence of sulphuric acid the precipitate ap- proaches to the composition and appearance of herapathite. See Cinchonine, d. Platinic chloride, in solutions not very dilute, a bright yellow precipitate, C 20 H 24 N 2 O 2 (HCl) 2 PtCl 4 , soluble in 1 500 parts of cold water or in 2000 parts of boiling alcohol. Tannic acid, a yellow- white amorphous precipitate (see p. 48), easily soluble in warm hydrochloric acid. Picric acid, in satu- rated aqueous solution, a yellow amorphous precipitate, soluble in alcohol, from which it crystallizes. Potassium sulphocyanate, in concentrated solutions, a white precipitate, more soluble than the sulphate (HESSE), used in microchemical examination, p. 101. Sulphates give a precipitate in neutral solutions of hydro- chloride and hydrobromide of quinine, if not diluted to the ex- tent of the solubility of quinine sulphate. Concentrated sul- phuric acid causes no color; Froehde's reagent a greenish color. Potassium iodide, in neutral solutions moderately dilute, does not precipitate quinine salts (separation from quinidine). A saturated solution of quinine sulphate is not affected. The slightest acidulation, such as may take place in the stomach, may result in the liberation of iodine and the formation of insoluble quinine iodides resembling herapathite. Normal tartrates, as potassium sodium tartrate, precipitate moderately concentrated solutions of quinine salts, the normal tartrate of quinine being a little more soluble (c) than that of cinchonidine, and much less soluble than those of quinidine and cinchonine (to be observed in cinchonidine separation by tartrate). e. Separations. All the cinchona alkaloids, in aqueous solu- tions of their salts, or other solutions of free alkaloid, are evapo- rated to dryness at 100-125 C C. without loss. From substances insoluble in ether, chloroform, or amyl alcohol, quinine is sepa- rated by action of these solvents, none of which dissolves salts of quinine, except chloroform very slightly. Benzene in sufficient quantity dissolves quinine, as does aqueous ammonia. Methods of separation of quinine from Cinchona Bark are given, pp. 102 to 111; from other Cinchona Alkaloids, index at p 111. From Morphine and from Strychnine quinine is pretty nearly sepa- rated by its solubility in ether, less fully separated by its solu- bility in ammonia. In the sulphates quinine is approximately 'Tho author, 1*7; : Ain. Jour. Phar., 49, 483. 134 CINCHONA ALKALOIDS. separated from Morphine and from Atropine by the differences of solubility in water. From Salicin it is well separated, as free alkaloid, by its insolubility in water. From Citrate of Iron and Quinine. The assay method of the U. S. Ph. is as follows : " The salt contains 12 per cent, of dry quinine. It may be assayed as follows : Dissolve 4 grams of the scales in 30 c.c. of water, in a capsule, with the aid of heat. Cool, and transfer the solution to a glass separator, rinsing the capsule; add an aqueous solution of 0.5 gram of tartaric acid, and then solution of soda in decided excess. Extract the alka- loid by agitating the mixture with four successive portions of chloroform, each of 15 c.c. Separate the chloroformic layers, mix them, evaporate them in a weighed capsule, on the water- bath, and dry the residue at a temperature of 100 C. (212 F.) It should weigh 0.48 gram." The Br. Ph. process is as follows : " Fifty grains [or 4 grams] dissolved in a fluid-ounce [or 35 c.c.] of water and treated with a slight excess of ammonia gives a white precipitate, which, when dissolved out by successive treat- ments of the fluid with ether or chloroform, and the latter evapo- rated, and the residue dried until it ceases to lose weight, weighs eight grains [or 0.639 gram]." Mr. J. C. FALK' adv r ises to add 1 gram of tartaric acid in the U. S. Ph. process, as he found the 0.5 gram insufficient to keep the iron in perfect solution. The four portions of chloroform are often insufficient. The solvent should be applied till a portion ceases to give test for quinine. Analysts often find it difficult to recover the entire quantity added. The use of a continuous extraction-apparatus for liquid's is desirable. Mr. Falk recovered 11.925 from the addition of 12. The recovered alkaloid is tested most readily by solubility in ether, more certainly by the application of the Ammonia Test to free alkaloid (p. 139). Where the ammonia test is the official standard for quinine hydrate and its several salts, it is the just and -indisputable stan- dard for the alkaloid obtained from all preparations of quinine, such as pills, scales, elixirs, etc. Of 34 samples of citrate of iron and quinine assayed by Dr. DAVENPORT, State Analyst of Drugs in Massachusetts, 2 by the U. S. Ph. method, 85 per cent, fell below the pharmacopoeial requirement, though the greater proportion were not in the phar- macopoeial form of the preparation. From Coated Pills of Quinine Salts. The following method 1 1884: Am. Jour. Phar., 56, 316. 2 "Fifth Annual Report State Board of Health," etc., Mass., 1884, p. 162. QUININE. 135 contributed by HENRY B. PARSONS, ' and verified by use in his constant practice, is confidently recommended : Take a sufficient number of pills to represent 20 or 40 grains of sulphate of qui- nine ; a treat, in a very small Wedgewood mortar, with 5 c.c. cold water until the coating dissolves and a smooth and uniform paste is obtained ; add 2 grams (31 grains) of freshly slaked lime in powder ; mix thoroughly and dry the mixture slowly in the mor- tar by a steam or water bath. The dry mass is to be finely pow- dered and transferred 3 to a Tollens apparatus for continuous percolation, 4 and thoroughly extracted with stronger ether. Eva- porate the ethereal solution jn a weighed flask, dry for one hour at 125 C., and weigh as anhydrous quinine. Grams of anhy- drous quinine X 20.7673 = grains of quinine sulphate (7H 2 O). f. Quantitative. Gravimetric estimation as free alkaloid. Quinine is frequently estimated by weighing the residue from a solution of the separated alkaloid in ether, chloroform, or amyl alcohol a method without objection (see , p. 134). The residue is preferably dried first at a very moderate heat or over sulphuric acid to avoid melting (), and finally at about 120 C., and cooled in a desiccator. The objection to precipitation for weight is the loss by solubility in water. Sodium hydrate is without ob- jection as a precipitant. In precipitating quinine sulphate aci- dulate solution with, sodium hydrate, and washing on the filter until the washings gave no cloudiness with barium chloride, a loss of 11.6 per cent, of the quinine was sustained. The solu- bility in sodium sulphate solution is about the same as that in pure water. Dry quinine, washed on the filter, ordinarily loses about 0.0002 gram per c.c. of wash- water; but a watery filtrate fully saturated with quinine will contain about 0.0006 1 1883: New Rem., 12, 67; Proc. Am. Pharm., 31, 270. 2 The smaller number is sufficient if manipulations are made with care and the balance is sensitive to tenths-milligram. 3 By use of a small steel spatula. The mortar then rinsed with a little of the ether. 4 In absence of a Tollens apparatus good results may be obtained by a very careful operation on an aliquot part of the solution as follows : Transfer the dry mass to a small, flat-bottomed flask ; measure in an exactly taken volume of stronger ether, [stopper, and weigh] and agitate the stoppered vessel, occasion- ally, while it stands for 12 hours or more. [Weigh again and add ether to restore the loss if any has occurred.] By use of a pipette measuring accurately [and agreeing with the measure by which the ether was taken], take off from the clear ethereal solution an aliquot part by volume of the ether taken, and evaporate as directed for the percolate. Chloroform does not work as well as ether as a solvent. With a faithful execution of the process the loss is not over % per cent. In answer to the opi- nion of MASSE (1885) that quinine suffers loss by action of lime at 100 C., see PASSMORE (1885). 136 CINCHONA ALKALOIDS. gram per c.c. of the liquid (c). 1 The precipitate is preferably dried tirst at a gentle heat, and at last at about 120 C. (248 F.), as the last molecule of water is difficult to expel at 100 C. Heat to about 170 C. is borne without loss of alkaloid. The dried alkaloid must be cooled in a good desiccator, as it readily acquires water from the air. Gravimetric determination as crystallized sulphate, dried at 100 C. (or 115 C.) to anhydrous sulphate, or at 60 C. to effloresced sulphate (2H 2 O), is directed under Separation of Cin- chona Alkaloids, p. 113. Gravimetric determination as quinine mercuric iodide by precipitation of the acidulated solution of the sulphate, with Mayer's solution, gives fair results. The precipitate is washed, and dried at 100 C., when 2.900 grams indicate 1.000 gram of quinine (as dried at 100 C.) 2 The composition of the precipitate is per- haps liable to variation by action of solvents, bat it is almost in- soluble in water. The precipitate hy phosphomolybdate, in acid- ulated solution, may be washed, dried below 70 C.. and weighed, when 1 gram of quinine is represented by about 3.665 grams of, the precipitate, 3 the result being properly controlled by a par- allel operation upon a known quantity of pure quinine. Volumetric estimation ~by Mayer's Solution. The precipitate, as stated under d (p. 132), has very little solubility, but its com- position is probably varied by conditions of temperature, etc. According to Mayer, in dilution of 1 to 800, 1 c.c. of the re- agent = 0.0108 gram of anhydrous quinine. 4 It is advisable to control the results by a parallel titration of a solution of quinine of known strength. Estimation in herapathite (DE YRIJ, 1882). Preparation of the Reagent, lodosulphate of Chinoidine. Of commercial chinoidine 1 part is heated on the water-bath with two parts of benzene, whereby the chinoidine is partly dissolved. The clear, cold benzene solution is shaken with an excess of weak sulphuric acid, whereby a watery solution of acid sulphate of chinoidine is obtained. After ascertaining in a small part of this solution the amount of amorphous alkaloid contained in it, so that its whole 1 "Laboratory Notes," by the author, 1877: Am. Jour. Phar., 49, 481; Jour. Chem. Soc., 32, 933; Jahr. Phar., 1877, 419. 2 "Laboratory Notes," by the author, 1877 (where last cited). 3 Last citation. *BLYTH, 1881: The Analyst, 6, 161; New Rem., u, 34; Proc. Am. Phar., 30, 410; Jour. Chem. Soc., 40, 1176. The factor 0.0108=f of ^-^ of the mo- lecular weight, and indicates the formula (CaoH^NQOa^lHI)*, (HgI 2 )s for the precipitate, but this is not supported by the gravimetric results (A. H. PRESE YEIJ, 1875), is soluble in 200 parts of water at 14 C. Quinidine oxalate, (C 00 H 22 IS" 2 O Q ) H 2 C 2 O 4 .H 2 O, dissolves in 150 parts of water at 15 C. d. In solutions of the sulphates, and especially in solutions acidulated with sulphuric acid, quinidine exhibits strong blue fluorescence. (See Quinine, d.) The chloroformic solution of the sulphate has a green fluorescence (HESSE, 1879). Quinidine responds to the thalleioquin test (p. 130). Sulphuric acid gives no color ; Froehde's reagent, a greenish color. Iodide of po- tassium causes in neutral solutions of quinidine salts a crystal- line precipitate of quinidine hydriodide, C 20 H 24 N 2 O 2 HI, soluble in 1250 parts of water at 15 C. (DE YKIJ)? Immediate precipi- tation is obtained only in somewhat concentrated solution, and is incomplete. Full crystallization within the limit of solubility is obtained by warming the mixture and stirring it with a glass rod from time to time as it cools, then leaving some hours at a low temperature, stirring at intervals. The reagent should be neutral, and added in such proportion that the quantity of solid potassium iodide shall nearly equal the quantity of alkaloid in solution. The crystals slowly formed in dilute solutions are leaf-form. In acidulous mixtures of sufficient concentration bihydriodide of quinidine is formed, in golden crystals, soluble in 90 parts of water at 15 C. (DE YRIJ). With the alkalies and alkali carbo- nates quinidine gives nearly the same reactions as quinine, the precipitate being very much less soluble in excess of ammonia. In presence of quinine the quinidine precipitate requires a good excess of ammonia to dissolve it, and the precipitate is apt to re- appear, crystalline on standing. With the general reagents for alkaloids quinidine reacts nearly the same as quinine, so far as the reactions have been examined. The dextrorotatory power of quinidine is given on p. 123. e. Separations of quinidine are obtained chiefly (1) by its crystallization as hydriodide (d, /*), and (2), except from cincho- nine, by solution of the sulphate in chloroform (c). See Separation of Cinchona Alkaloids, p. 112, for an index of methods of separa- tion. Also compare the special separations of Quinine (/*), p. 141. CINCHONIDINE. 1 5 7 f. Quantitative. In estimating quinidine as hydriodide, crys- tallization is secured, as indicated under d, giving twenty-four hours for the crystals to form. The drained crystals, sparingly washed, are dried in a warm place, and weighed as C 20 H 24 N 2 O 2 HI, adding y^-g- of the weight of the crystallizing liquid and wash- ings. The anhydrous quinidine constitutes 71.75 per cent, of the total hydriodide. g. Tests for impurities. "The salt [sulphate] should not be more than very slightly colored by undiluted sulphuric acid (absence of [more than very slight proportions of] foreign organic matters). . . . If 0.5 gram each of sulphate of quinidine and of iodide of potassium (not alkaline to test-paper) be agitated with 10 c.c. of water at about 60 C. (140 F.), the mixture then mace- rated at 15 C. (59 F.) for half an hour, with frequent stirring, and filtered, the addition to the nitrate of a drop or two of water of ammonia should not cause more than a slight turbidity (absence of more than small proportions of conchonine, cinchonidine, or qui- nine)" (U. S. Ph., 1880). One part quinidine sulphate dissolved in 10 parts hot water is digested at 60 C. with 1 part potassium iodide, the mixture cooled, with agitation, and the filtrate tested with 1 or 2 drops of ammonia- water (Ph. Fran., 1884). CINCHONIDINE. The Quinidine of HENRY and DELONDRE (1833). 1 Isomeric with cinchonine, C 19 H 22 N 2 O=294. a Crystal- lizes anhydrous. The free alkaloid is little known in commerce, but the sulphate since about 1876 has been used quite largely, and to a much greater extent than any other distinct cinchona alkaloid except quinine. Cinchonidine is the chief general impu- rity in quinine salts in use. The Rational Formula is indicated at p. 98. Proportion in Cinchona Bark, p. 97. Separation from the Bark, in total alka- loids, pp. 102-111. Separation from other Cinchona Alkaloids, index of methods at p. 112. Distinction from other Cinchona Alkaloids, index of methods at p. 100. Microscopic identifica- tion, p. 101. Eotatory Power, p. 123. The crystalline forms and heat-reactions of cinchonidine and its salts are given under &, and their solubilities under c (p. 158). Cinchonidine is characterized by chemical reactions stated under 1 Also of WINCKLER, 1844. See foot-note under Quinidine (p. 154). This alkaloid, isomeric with cinchonine or a mixture containing it, was named cin- chonidine by PASTEUR in 1853, and by WITTSTEIN in 1856. At present all au- thorities agree in this name. * SKRAUP, 1878. PASTEUR, C 2 oHa 4 NaO, 1853. See foot-note under Cincho- nine. 158 CINCHONA ALKALOIDS. d (p. 159), t?he tartrate precipitate with concurring qualitative re- actions being the chief dependence for identification. The alka- loid is estimated by weight of the tartrate or of the free alkaloid {/*). The tests for impurities and the amount of water of crys- tallization of the sulphate are discussed under g, p. 160. a. Crystallization and heat reactions. Cinchonidine crystal- lizes, anhydrous, in distinct, lustrous forms ; from alcohol in short prisms ; from dilute alcohol in fine, thin plates. It melts at 200-201 C. (HESSE, GLAUS, 1881). Cinchonidine sulphate crys- tallizes in white, silky, lustrous needles or in thin, quadratic prisms. " In colorless silky crystals, usually acicular " (Br. Ph., 1885). 41 Ordinarily from aqueous solution little concentrated, in bril- liant needles, with 6H 2 O. From concentrated [hot] aqueous so- lution, in [hard] prisms, with 3H 2 O. And from alcohol in fine prisms, with 2H 2 O. The salt with 6H 2 O is officinal" (Ph. Fran., 1884). The crystals containing 6H 2 O effloresce to some extent in the air, losing either one or four of the 6H 2 O, as determined by the mode of production of the crystals (Ladenburg's " Handwor- terbuch"). In moist air the anhydrous salt gains 2H 2 O. All water of crystallization is expelled on the water-bath. Cinchoni- dine sulphate with quinine sulphate crystallizes with 6H 2 O (Kop- PESCHAAR, 1885). Cinchonidine hydrochloride, with 1 molecule of H 2 O, forms characteristic crystals, double pyramids, octahe- drons (HESSE). From supersaturated solution silky, prismatic needles are sometimes obtained, with 2H 2 O. A bihydrochloride is also obtained, forming large, lustrous, monoclinic crystals with 1 molecule of water. Cinchonidine hydrobromide crystallizes, with H 2 O, in long, colorless needles (Ph. Fran.) The dihydro- bromide, with 2H 2 O, crystallizes in very slightly yellowish pro- longed prisms (Ph. Fran.) Cinchonidine tartrate, normal, with 2H 2 O. is a white crystalline precipitate, becoming anhydrous at 100 C. Cinchonidine oxalate, normal, crystallizes, with 2 or 6 H 2 O, in prisms or a crystalline powder. o. Cinchonidine has a very bitter taste, and is administered in doses not far from those of quinine. In excess it is liable to prove poisonous, with action resembling that of picrotoxine (SEE and BOCHEFONTAINE, 1885). Death has resulted from taking 160 grains (WILLIAMS, 1884). c. Solubilities. Cinchonidine is soluble in 1680 parts of water at 10 C., in 20 parts of 80$ alcohol, in 76 parts of ether of sp. gr. 0.729, and easily soluble in chloroform (HESSE, 1865). In 1.6.3 parts of alcohol of 97# at 13 C., and in 188 parts ether CINCHONIDINE. 159 of sp. gr. 0.72 at 15 C. (HESSE, 1880). Readily soluble inamyl alcohol. Slightly soluble in ammonia. In presence of quinine its solubility in ether is increased. The normal salts of cinchoni- dine, with ordinary acids, are neutral. Cinchonidine sulphate, (C 19 H 22 N 2 O) 2 H 2 SO 4 . 6H 2 O = 794 (see a\ is soluble "in 100 parts of water and in 71 parts of alcohol at 15 C. (59 F.), in 4 parts of boiling water, in 12 parts of boiling alcohol, freely in acidulated water, and in 1000 parts of chloro- form (the un dissolved portions becoming gelatinous) ; very spar- ingly soluble in ether or benzene " (IT. S. Ph.) In 300 parts boiling chloroform. Mixed with quinine sulphate it becomes somewhat soluble in ether (PAUL, 1877). In presence of cincho- nine or quinidine sulphate its solubility in chloroform is increased (Prescott and Thum, 1878). Cinchonidine hydrochloride, C 19 H 22 lSr 2 O HC1.H 2 O= 348.4 (see a), is soluble in 30 parts of water at 15 C., freely soluble in boiling water, in alcohol, and in chloroform, and soluble in 325 parts of ether at 10 C. (CABLES, 1874). From the chloroformic solution, in long standing, there are formed prismatic crystals of an instable compound with chloroform (HESSE, 1875). Cinchonidine hydrobromide, C 19 H 22 K 2 OHBr.H 2 O^393 (Br=80), is soluble in 40 parts of cold water, and freely soluble in hot water (Ph. Fran.) Cincho- nidine tartrate, (C 19 H 22 N 2 O) 2 C 4 H 6 O 6 .2H 2 O, is soluble in 1265 parts of water at 10 C., less soluble in solution of rochelle salt. The normal oxalate, (C 19 H 22 N 2 O) 2 H 2 C 2 O 4 . 6H 2 O, is soluble in 252 parts of water at 12 C. for 1 part of the anhydrous salt. d. Cinchonidine does not form fluorescent solutions nor give the thalleioquin reaction. Potassium sodium tartrate and other normal tartrates precipitate Cinchonidine, as normal tar- trate (see above, c\ crystallizing from hot solution in fine nee- dles. An excess of the reagent renders the test the more delicate. A separation from cinchonine, and to some extent from quini- dine, hardly at all from quinine. Cinchonidine is precipitated from solutions of its salts by the alkalies and alkali carbonates, the precipitate appearing at first amorphous, slowly becoming crystalline, and being somewhat soluble in excess of ammonia (see Quinine, g, " Kerner's Test "). The general reagents for alkaloids give customary reactions with cinchonidine. In the test for iodosulphate (see Quinine, d, Herapathite, p. 131) green crystals of golden lustre are obtained. Respecting the microche- rnical test with sulphocyanate, see under Cinchona Alkaloids, p. 101; the levorotatory power, p. 122. e. Separations of cinchonidine are indexed under Cinchona 160 CINCHONA ALKALOIDS. Alkaloids, Separation of, p. 112. Compare also with special methods for the separation of Quinine, p. 139. f. Cinchonidine can be estimated, gravimetrically, as anhy- drous alkaloid by drying the precipitate obtained with sodium hydrate on the water-bath (a). More often it is estimated (ac- cording to directions given under Cinchona Alkaloids, Separa- tion) by weight of the anhydrous tartrate (C 19 Ho 2 N 2 O) 2 C 4 H 6 O 6 738 (79.67$ cinchonidine). The precipitate is dried on the water-bath. As to optical estimation, see p. 124 under Cin- chona Alkaloids. For estimation in mixture with quinine, both as sulphates, by action of ammonia, see under Quinine, g y " Kerner's Test." g. Tests for impurities. "If 0.5 gram of the salt [sul- phate] be digested with 20 c.c. of cold distilled water, 0.5 gram of tartrate of potassium and sodium added, the mixture mace- rated, with frequent agitation, for one hour at 15 C. (59 F.), then filtered and a drop of water of ammonia added to the fil- trate, not more than a slight turbidity should appear (absence of more than 0.5 per cent, of sulphate of cinchonine, or of more than 1.5 per cent, of sulphate of quinidine) " (U. S. Ph., 1880). 1 The test originated with HESSE (1875), who directed to digest 0.5 gram of the salt with 20 c.c. water at about 60 C., add 1.5 grams of the tartrate, and after an hour filter and test with am- monia. The Ph. Fran. (1884) directs digestion with boiling water, 40 parts, and an excess of the tartrate, then setting aside 24 hours before testing. The three parts of tartrate directed by Hesse give a little closer results than are obtained with addition of one part (c, p. 159). The test does not reveal quinine, tartrate of which takes 910 parts water at 10 C. to dissolve it, but shows either cinchonine or quinidine. To test for presence of quiui- dine, add to the filtrate from tartrate precipitation potassium iodide equal to quantity of cinchonidine salt taken, and stir from time to time, when quinidine will be revealed by precipitation, and the second filtrate can be tested, with a drop of ammonia- water, for cinchonine. Either quinine or quinidine will be re- vealed by fluorescence (Quinine, d). The sulphate u should not be colored by addition of sulphuric acid (absence of foreign or ganic matters) " (U. S. Ph., 1880) ; should not suffer " more than a faint yellow coloration" (Br. Ph., 1885). As to amount of crystallization-water in cinchonidine sul- phate, see a. The loss by drying at 100 C. is limited by the 1 TEETER, Univ. Mich., 1880: New Rem., 9, 258. CINCHONINE. 161 U. S. Ph. and Br. Ph. to the amount of 3H 3 O, or 7.3 per cent.; by the Ph. Fran, to the proportion of 6H 3 O, 13.60 per cent. Five ordinary commercial samples, dried at 100 C. and cooled in a desiccator, gave a loss of from 6.36 per cent, to 7.04 per cent. 1 CINCHONINE. C 19 Ho 2 N 2 O:=294. a Crystallizes anhydrous. See Cinchona Alkaloids, p. 97, for yield in cinchona barks, and p. 98 for chemical constitution. Methods of Separation from the Bark, in the total alkaloids, are given pp. 102 to 111. From the other cinchona alkaloids the methods of separation* are indexed at p. 113, the means of distinction are indexed at p. 100. Methods of microscopic in- quiry, p. 101. Rotatory Power, p. 123. Crystallization and Heat-Reactions for the alkaloid and its salts, below. Solubili- ties of the alkaloid and its salts, p. 162. Physiological effects, p. 162. Cinchonine is identified by the agreement of a number of al- kaloidal reactions and solubilities, and, after separation, by nega- tive results excluding other alkaloids (d) ; the reaction with fer- ricyanide, carefully obtained under the magnifier, is somewhat characteristic, as likewise is the iodine reaction. For separations, references are noted, in addition to those above, at 0, p. 164. The alkaloid is estimated by its weight in the free state, anhy- drous (/*), and has been estimated by Mayer's solution (p. 164). Tests for purity are given (g) at p. 164. a. Crystallization and Heat- Reactions. Cinchonine ap- pears in white prisms or needles, anhydrous, in the monoclinic system, obtained by crystallization from alcohol. In watery so- lution of its salts ammonia gives a flocculent, crystalline precipi- tate ; in solution of its salts in dilute alcohol needles are obtained by action of ammonia. It melts at 268.8 C. (SKRAUP, 1878). Quickly heated, at 248-252 C. ; slowly heated, at 236 C. (HESSE, 1880). Heated, not quite to the melting point, in a stream of hydrogen or ammonia, a sublimate is obtained, of undecomposed Cinchonine, in prismatic needles, with products of partial decom- 1 Taking cinchonidine at Ci 9 H 2 2 . . ., 6H 2 0=13.60 per cent, of the sulphate. atC 20 H 24 ..., 6H 2 0=13.13 " " at C 19 H 22 . . ., 3H 2 0= 7.30 atC 20 H 2 4 . . ., 3H 2 O= 7.03 " " 2 SKRAUP, 1878. PASTEUR, 1853, C 20 H 24 N 2 O. Skraup found it necessary to separate Cinchotine, Ci 9 H 24 N 2 O (p. 93), to obtain pure cinclionine for analysis. His figures support the new formula better than they do the old. Hesse ac- cepts Skraup's formula; and it is taken as the basis of'hypotheses of the consti- tution of cinchona alkaloids (p. 98). Pasteur's formula is retained in the Br. .Ph. of 1885; Skraup's is adopted in the Ph. Fran, of 1884. 1 62 CINCHONA ALKALOIDS. position (HLASIWETZ, 1851). In melting it turns brown and sub- limes slowly. Cinchonine sulphate* with 2H 2 O, crystallizes in short, hard, monoclinic prisms, transparent, of a vitreous lustre, permanent in the air, parting with all the crystallization- water at 100 C. Triturated at 100 C. it glows with greenish light. It melts at about 240 C. Cinchonine hydrochloride, with 2H 2 O, forms four-sided rhombic prisms or fine, silky needles, permanent in the air, efflorescent in a desiccator, becoming anhydrous at 100 C., and melting at about 130 C. The hydrobromide forms long, lustrous prismatic needles (LATOUR, 1870 ; BULLOCK, 1875). Tlie hydriodide, normal, crystallizes, with H 2 O, from a hot-satu- rated solution, in hard, colorless, monoclinic prisms. The tar- irate, normal, with 2H 2 O, crystallizes from a hot solution in clusters of needles. Cinchonine oxalate, normal, with 2H 2 O, appears in crystalline powder, or from dilute hoi solution in ]arge prisms, becoming anhydrous at 130 C. 5. Free cinchonine is nearly tasteless at first, with an in- creasing bitter after-taste. The soluble salts of cinchonine are very bitter. The dose of the sulphate is 1 to 10 grains (Br. Ph.) c. /Solubilities. " Almost insoluble in hot or cold water, soluble in 110 parts of alcohol at 15 C. (59 F.), in 28 parts of boiling alcohol, 371 parts of ether, 350 parts of chloroform, and readily soluble in diluted acids " (U. S. Ph.) In 3670 parts water at 20 C. ; in 371 parts of ether of sp. gr. 0.73 at 20 C. ; in 125.7 parts of alcohol of sp. gr. 0.852 at 20 b C. (HESSE, 1862). In 356 parts of chloroform strictly alcohol-free, at 17 C., but more freely soluble in mixtures of chloroform and alcohol than in alcohol alone (OUDEMANS, 1873). In 40 parts of "chloro- form" (PETTENKOFEK) ; in 35 parts of "chloroform" (HAGER). Moderately soluble in amyl alcohol ; sparingly soluble in hot benzene ; scarcely at all soluble in cold benzene. 1 [Nearly inso- *In 1875 the writer made determinations of solubilities of cinchonine in su- persaturation with certain water-washed solvents, with the results which follow. The " nascent" state was that of liberation from sulphate solution by ammonia, while in contact with the hot solvent, all the solvents being applied at their boiling points: Cinchonine. Ether. Chloroform. Amyl ale. Benzene. At 15 C.: sp.gr. 0.7290. sp. gr. 1.4953. sp. gr. 0.8316. sp. gr. 0.8766. Crystallized 719 828 Amorphous 563 ... 40 531 Nascent 526 178 22 376 From "Comparative Determinations of the Solubilities of Alkaloids in Crystal- line, Amorphous, and Nascent Conditions: Water- washed Solvents being used." A. A. A. S., 1875, 24, i. 114; Jour. Chem. Soc., 29, 403; Am. Chem., 6, 84. CINCHONINE. 163 luble in petroleum benzin (DRAGENDORFF). But slightly soluble in ammonia-water. Cinchonine neutralizes the strong mineral acids, its sulphate having " a neutral or faintly alkaline reaction " (U. S. Ph.) Cinchonine sulphate, (C 19 H 22 N" 2 O) H SO 4 . 2H 9 O, is soluble "in about 70 parts of water and in 6 "parts of alcohol at 15C. (59 F.), in 14 parts of boiling water, 1.5 parts of boiling alcohol, 60 parts of chloroform, and easily soluble in diluted acids ; in- soluble in ether or benzene " (U. S. Ph.) In 65.5 parts water at 13 C. (HESSE). Cinchonine hydrochloride, C 19 R 22 N 2 O HC1.2H 2 O, is soluble in 24 parts of water at lu C. ; iii 1.3 parts of alcohol of sp. gr. 0.85 at 16 C. ; in 273 parts of ether of sp. gr. 0.7305 at 15 C. (HESSE). The hydrobromide dissolves in 18 parts of water at 21 C. (BULLOCK, 1875), and is freely soluble in alcohol. The hy- driodide, C 19 H 22 N 2 O HI.H 2 O, is freely soluble in water, in al- cohol, and in chloroform, and somewhat soluble in ether. The normal tartrate, (C 19 H 22 N 2 O) 2 C 4 H 6 O 6 . 2H O, is soluble in 33 parts of water at 16 C, (HESSE), the solution having a slightly alkaline reaction. The tannate is very slightly soluble in water, and is not soluble in all proportions of cold hydrochloric acid. Normal oxalate, (C 19 H 22 N 2 O) 2 H 2 C 2 O 4 .2H 2 O, dissolves in 104 parts of water at 10 C. d. In qualitative reactions cinchonine is characterized by negative results. It does not respond to the thalleioquin test ; its solutions do not fluoresce ; its hydriodide and its tartrate are freely soluble in water. Its periodides and iodosulphates are distinguished from those of quinine only by a careful observance of conditions. Potassium ferrocyanide solution not in excess, with slightly acidulated solutions of cinchonine salts, gives a yellowish-white precipitate of cinchonine ferrocyanide, at first amorphous, becoming crystalline on standing or while cooling, in radiate or fan-like clusters or rhombic plates, as seen under the microscope. The crystals are golden-yellow. The precipitate is soluble in excess of the reagent, more readily before crystallizing. The solution made by dissolving the amorphous precipitate in just enough excess of the reagent soon yields crystals again (a difference from the reaction with quinine, BARFOED). Quinine gives a precipitate more permanently soluble in excess of the re- agent. If a warm-saturated alcoholic solution of cinchonine be neutralized with hydrochloric or very slightly acidified with acetic acid, then to each c.c. about 10 drops of a one per cent, so- lution of iodine with potassium iodide be added, and water added 1 64 CINCHONA ALKALOIDS. to incipient precipitation, fine, lustrous red-brown to brown-yel- low crystals of superiodide are gradually formed in the cooling of the liquid. The forms are four-sided rhombic plates. Under just these conditions, and in absence of sulphates, quinine gives a precipitate of tarry consistence (BARFOED, 1881). Treated as a sulphate, as directed under Quinine, <$, for herapathite, cincho- nine gives nearly black crystals, brown to brown-yellow when in thin layers under the microscope. The general reagents for alkaloids precipitate cinchonine, in most cases quite perfectly. Tannic acid gives a precipitate not easily dissolved by hydrochloric acid. The alkali hydrates and carbonates give a quite complete precipitate of cinchonine (see #), not at all soluble in excess of sodium hydrate, and (in absence of other cinchona alkaloids) almost insoluble in excess of ammonia. (See under Quinine, g, " Kerner's Test "). In dilute solutions, and more favorably with excess of ammonia, the precipitate becomes crystalline on standing a short time, and is seen under the microscope in radiating tufts of needles. e. Separations of cinchonine are indexed under Cinchona Alkaloids, Separation of, p. 113. Compare also special modes of separation of Quinine, p. 139. f. Quantitative. Cinchonine is estimated, gravimetrically, as free alkaloid, anhydrous. From aqueous solution of its salts it is precipitated by solution of sodium hydrate, washed with water, and dried at 100 C. It may be estimated by alkalimetry, with tenth or hundredth normal sulphuric acid solution. With Mayer's solution the equivalent of 1 c.c. was given by Mayer (1862) at 0.0102 gram, and the composition of the precipitate was indi- cated to be C^HggNgO HI HgI 2 by Groves (1859), but further data are needful as to the value of the precipitation, and the action of the reagent is greatly affected by conditions. g. Tests for distinctions and impurities. " A solution of the alkaloid in dilute sulphuric acid should not exhibit more than a faint blue fluorescence (absence of more than traces of quinine or quinidine). On precipitating the alkaloid from this solution by water of ammonia it is very sparingly dissolved by the latter (difference from and absence of quinine), and requires at least 300 parts of ether for solution (difference from quinine, quinidine, and cinchonidine)." If the sulphate " be macerated for half an hour, with frequent agitation, with 70 times its weight of chloroform at 15 C. (59 F.), it should wholly, or almost wholly, dissolve (any more than traces of sulphate of cinchoni- QUINOLINE. 165 dine or sulphate of quinine remaining undissolved). It should not be colored by contact with sulphuric acid (absence of foreign organic matters)." "If 1 grain [of the sulphate] be dried at 100 C. until it ceases to lose weight, the residue, cooled in a desicca- tor, should weigh not less than 0.952 l gram" (U. S. Ph.. 1880). " Twenty-five grains of the salt should lose 1.26 grains of mois- ture when dried at 212 F. (100 C.), and should then almost wholly dissolve in four ounces by weight of chloroform " (Br. Ph., 1885). QUINOLINE. Chinoline. , Leucoline. CgH 7 N 129. The structure of naphthalene with N in the place of one CH (Korner, 1870). (See under Constitution of Cinchona Alkaloids, p. 97). An artificial volatile alkaloid obtained as follows : (1) By distilling cinchonine or quinine, strychnine or brucine, with fixed alkali. In presence of copper oxide the quinoline is obtained nearly free from lepidine (C 10 H 9 N) and dispoline (C U H 1:1 N"), next homologous members of the quinoline series (C n H 2n _5N). (2) The later distillate of coal-tar, the " dead-oil," contains qui- noline. For some years this product was held not identical but only isomeric with the quinoline from cinchonine, and it was named leucoline, C 9 H 7 K. In 1883 HOOGEWERFF and v. DORP obtained cinchonine-quinoline free from previous impurities, whereby its identity with the quinoline of coal-tar or bone-oil is believed to be established. The same investigators, however, find an isomer of quinoline in bone-oil. (3) From bone-oil. (4) By synthesis in several ways, best from nitrobenzene, with ani- line, according to the equation on p. 97. As obtained from these several sources quinoline is itself one body. But as manufactured, either for coloring matters or for me- dicinal purposes, quinoline is likely to retain some degree of impurities derived from its sources. Cincho-quinoline is ac- companied by lepidine. Artificial quinoline is sometimes inter- mixed with nitrobenzene. Certainly for medicinal uses, at pre- sent, quinoline offered for sale should be presented with the name of its source. a. Quinoline is a colorless, mobile liquid, transparent when pure, very refractive, and turning brown by exposure in the air and light. Specific gravity, at 15 C., 1.084; at 20 C., com- pared with water at same temperature, 1.094 (SKRAUP, 1881). Boiling point, 231. 5 C. (SFALTEHOLTZ) to 241. 3 C. (KRETSCHY, 1 If cinchonine be C, 9 H 22 . . ., 2H 2 0=r4.99 per cent, of the sulphate. C 20 H 24 . . ., 2H 2 0=4.80 1 66 CINCHONA ALKALOIDS. 1881). It evaporates slowly but completely, on exposure, so that the oil-spot it forms on paper disappears on standing. Crys- tallizes in a freezing mixture of carbon dioxide and ether. The hydrochloride crystallizes in small white nodules ; the tar- trate in rhombic needles, forming under the microscope in colum- nar needles of good length ; the salicylate appears in a reddish- gray powder. b. Quinoline has a pungent, aromatic taste, slightly resem- bling peppermint- oil in its after-taste, without bitterness. It has a slight aromatic odor like bitter-almond oil. It is administered in doses as high as 1 gram (15 grains) or 2 grams (30 grains) in twenty-four hours (DONATH, 1881). In overdoses, to animals, it promptly causes death by asphyxia. 1 It is strongly antiseptic and antizymotic. It coagulates albumen and myosin (BERENS). It prevents the lactic, not the alcoholic, fermentation (DONATH). It is not found in the urine after administration. c. Soluble in water, sparingly when cold, freely when hot. Soluble in all proportions in alcohol, ether, and carbon disul- phide, and soluble in chloroform, benzene, amyl alcohol, carbon disulphide, and in fixed and volatile oils. The salts of quinoline are soluble in water. The tartratc, (C 7 H 9 N) 3 (C 4 H 6 O 6 ) 4 (FRIESE, BERNTHSEN, 1881), is soluble in 80 parts of water at 16 C.; in 150 parts of 90$ alcohol at 16 C.; in 350 parts of ether. It melts at about 125 C. The hydrochloride, C 9 H 7 N.HC1 (OECHSNER, 1883), is soluble in water, alcohol, chloroform, ether, and benzene, in the last two solvents sparingly in the cold. Melts at 94 C., and vola- tilizes. d. Quinoline is indicated by its odor, obtained from its salts on addition of a fixed alkali. Alkali hydrates precipitate it, in solutions not dilute ; the precipitate being soluble in ex- cess of ammonia, and easily taken into solution by ether, chlo- roform, and other solvents of the base. Solutions of quinoline salts are precipitated by the general reagents for alkaloids. According to Donath, the limits of precipitation, in certain favo- rable proportions of reagents, were as follows : For iodine in iodide of potassium, 1 to 25000 parts ; phosphomolybdate, 1 to 25000 parts ; mercuric chloride, 1 to 5000 parts ; potassium mercuric iodide, 1 to 3500 parts. The precipitate w r ith phosphomolybdate, yellow-white, dissolves colorless in ammonia ; with mercuric chloride, white. The precipitate by potassium mercuric iodide, 1885: Ther. Gazette, 9, 433. KAIRINES. 167 on adding hydrochloric acid, crystallizes in amber-colored needles. No color is caused by sulphuric or nitric acid (DONATH). By long heating with excess of sulphuric acid quinoline sulphonic acid is formed. Tests for impurities. In artificial quinoline by Skraup's process, nitrobenzene has been found as an impurity (0. EKIN, 1882). The salts should be completely soluble in water, the free base in water with sufficient acid. There should be no bitter taste (impurity from cinchonine). Alkali hydrates should not cause a colored precipitate. Cinchonine-quinoline, as prepared for use, and unless repeatedly distilled and recrystallized, con- tains lepidine (HOOGEWERFF and v. D ) ; and therefore when treated with amyl iodide, and then with caustic alkali, gives a bine color, formation of a cyanine (WILLIAMS), C 9 PI 7 NC 5 H 1;L . C 10 H 9 NC 5 H 11 I. Aqueous solution of pure quinoline salt [not alkaline] does not sensibly change the color of permanganate so- lution in the first eight or ten minutes (HAGER). KAIRINES. Methyl or ethyl substitutions in oxy-quinoline- tetrahydride, C 9 H 10 (OH)K. The methyl compound is C 9 H 9 (CH 3 )(OH)N=C 1 pH 13 NO ; the ethyl compound, C 9 H 9 (C 2 H 5 ) (OH)N=C n H 15 NO. The name kairine is used for the hydro- chloride. Oxyhydro-methylquinoline is termed Kairine M, and oxyhydro-ethylqumoline Kairine E or Kairoline. Derivatives of quinoline (E. FISCHER, 1883) of medicinal interest. The free bases are not stable in the air. a, c. The methyl base crystallizes in rhombic forms ; is spar- ingly soluble in water, soluble in alcohol, ether, and benzene, and acts as a strong base in forming salts. It boils at 114 C. The hydrochloride, C 10 H 13 NO . HCl-)-II 2 O, forms lustrous, monocli- nic crystals, generally found in a slightly colored crystalline pow- der, easily soluble in water. At 110 C. it loses its water of crys- tallization and turns violet. The sulphate, (C 10 H 13 N~O) 2 H 2 SO 4 , forms lustrous prisms. The ethyl base crystallizes in scales or plates, melting at 76 C., slightly soluble in water, freely soluble in alcohol, ether, and ben- zene ; hardly soluble in petroleum benzin. The hydrochloride, C 11 H 15 NO . HC1, forms white prisms, generally appearing in grayish-yellow crystalline powder, freely soluble in water, spar- ingly soluble in hydrochloric acid. b. The kairines have a bitter and saline, disagreeable taste and a penetrating odor. Ordinary doses are one-half to one gram 1 68 CINCHONA ALKALOIDS. (7 to 15 grains), and doses of 25 to 50 grains cause disturbance. 1 It is in part excreted unchanged in the urine (MERING, 1884). The ethyl compound differs from the methyl compound only in a somewhat longer duration of effect (Filehne). d. Kairines are indicated by the penetrating, characteristic odor of the free base, obtained in full from the salts on adding a fixed alkali, and by the bitter taste. In aqueous or alcoholic so- lution, treated with oxidizing agents, as dichromate and an acid, they give rosaniline colors, violet-blue to violet-red, in some reactions greenish tints being obtained. Ferric chloride gives a brown color in solutions, with gradual precipitation. Sodium nitrite in sulphuric acid solution gives orange to red colors. Po- tassium ferrocyanide gives an abundant precipitate ; phospho- tungstic acid a pale yellow precipitate. When the base is libe- rated, as in alkaline solutions, the kairines rapidly oxidize in the air, with deposition of brown, humus- like bodies. THALLINE. C 10 Hi 3 lTO. Tetrahydroparaquinanisoil. A de- rivative of paraquinanisoil. 2 One of the methyl kairines, isomeric with " kairine M." Thai line appears in pale yellow crystals, melting at about 42 C., boiling at 282 C. without decomposition. Its salts are given in doses of 0.25 to O.T5 gram. It is sparingly soluble in cold, more freely in hot water, and soluble in alcohol, ether, and petroleum ether. It makes stable salts ; but in all forms it is easy to suffer change, and the light affects it injuriously. The sulphate and tartrate are obtained in nearly white crystals or crys- talline powder, melting at 100 C., with browning. The sulphate is freely soluble in water, nearly insoluble in ether, but is some- what soluble in chloroform. Oxidizing agents produce an intense green color with tlialline, hence its name. Ferric chloride is a favorable oxidizing agent for the purpose, giving a deep emerald- green color, not changed by acidulatlon with sulphuric acid, but changed by reducing agents. In physiological effect tlialline resembles the kairines. 3 ANTIPYRINE. C n H 10 N O. A proposed commercial name for Dimethyl-oxy-quinizine,~ C 9 H 6 (N.CH 3 )(CH 3 )(O)K, the hypo- thetical base quinizine having the general formula C 9 H 9 (NH)N 'On use of kairine as an antipyretic, FILEHNE, 1882-1883. American uses summarized in Ttier Gazette, 9, 122 (Feb., 1885). 2 VuLPius. 1883: ArcUv d. Phar., [81. 22, 840; Jour. Chem. Soc., 1885, Abs.,398, 1022. 3 BEYER, 1886: Am. Jour. Phar., 58, 196. JAKSCH, 1884. ANTIPYRINE. 169 (L. KNORR, 1884 1 ). Of interest for medicinal uses as an anti- pyretic. a. Antipyrine crystallizes in needles, melting at 113 C. In commerce it appears as a white, crystalline powder, sometimes slightly colored. #. Of a very mild bitter taste, not disagreeable, and a barely perceptible odor. Dose, 1 to 2 grams (15 to 30 grains). 2 Double that of quinine (BUTLER, 1885). 40 to 50 grains have caused se- rious effects. It appears in the urine in about two hours after its administration, and can be detected by applying the ferric chloride test to the entire urine (CARUSO, 1885). c. Dimethyloxyquinizine is very freely soluble in water, al- cohol, or chloroform ; in about 50 parts of ether. The aqueous solution is neutral to test-papers. Antipyrine is a base of some strength, uniting with acids to form salts, from which it is set free by the alkali hydrates. d. Ferric chloride solution gives a decided red coloration, intense in solutions of 1 to 1000 parts ; the color being changed to yellow by strong acidulation with sulphuric acid. 8 Nitrous acid, as obtained by adding a little potassium nitrite and acidu- lating with dilute sulphuric acid, gives a bluish-green color in dilute, a green crystalline precipitate in concentrated, solutions characteristic of all the quinizines (KNORR). Two drops of fuming nitric acid, added to 2 c.c. of a 1 per cent, solution of antipyrine, cause a green color, and, after heating to boiling, another drop of the reagent gives a red color (Germ. rh. Commission). Tannic acid gives a white precipitate in a 1 per cent, solution. Tests for impurities The solution in two parts of water should be neutral, and colorless or faintly yellowish, free from sharp taste, and not changed by solution of hydrosulphuric acid (Germ. Ph. Commission). CINCHONICINE. See CINCHONA ALKALOIDS, pp. 91, 94. CINCHONIDINE. See CINCHONA ALKALOIDS, pp. 157-161. 1 The quinizines are derived from quinoline by the introduction of (NH), with additional 2H, into the quinoline molecule. The (NH) is attached to the N in the ring, this N being united to carbon by only two bonds, instead of three as in quinoline. KNORR: Ber. deut. chem. Ges. t 17, 546, 2032; Jour. 193. 3 Pharmacopoeia Commission of Germ. Apoth. Association. i;o COCA ALKALOIDS. CINCHONINE. See CINCHONA ALKALOIDS, pp. 161-165. CINCHOTANNIN. See TANNINS. CINCHOTINE. See p. 93. CINNAMIC ACID. See p. 69. COCA ALKALOIDS. Alkaloids of Erythroxylon Coca leaf. Cocaine, C 17 H 21 I^O 4 . The crystallizable natural alkaloid of fresh coca. Ecgonine, C 9 Hj 5 ^N"O 3 , crjstallizable. A product of cocaine by saponification, and liable, also, to be present in the leaf. Benzoyl- Ecgonine, C 16 H 19 NO 4 , crystallizable. A by-product of manufacture of cocaine from coca. (Present in the leaf ? ) Anhydride of ecgonine, C 9 H 13 NO 3 , crystallizable. Producible from ecgonine by moderately strong sulphuric acid with heat. Hygrine, a liquid volatile alkaloid (LossEN, 1865) little known, reported to form crystallizable salts. The existence of this alkaloid is not established. Amorphous alkaloids of coca. (" Cocainoidine, Cocaicine".) Said to be obtained in preparation of cocaine. Probably present in the leaf in some conditions of this article. Not studied. Chemical constitution. Cocaine, as an easily saponifiable body, prone to split, by hydratiori, into ecgonine^ benzole acid, and methyl alcohol, clearly has the immediate structure of me- thyl benzoyl ecgonine: C 9 H 13 (CH 3 )(C 7 H 5 O)NO 3 =C 17 H 21 NO 4 . The saponification of cocaine is accomplished by an acid^ which takes ecgonine into combination, or by an alkali which takes both benzoic acid and ecgonine into union, or even, it is pro- bable, by digestion with water, whereby benzoyl and methyl slowly become hydroxides. But whenever the necessary condi- tions are fulfilled with any saponifying agent, the change is shown by the equation : C 9 H 13 (CH 3 ) (C 7 H 5 0)N0 3 +2H 8 =C 9 H 15 N0 3 +C 7 H.O . OH+CH,. OIL Ecgonine, by loss of CO 2 , gives the constituents of a tropine. This change, effected by distilling the barium compound of ecgonine, shows a not distant chemical relationship between COCA ALKALOIDS. 171 cocaine and the atropine group of alkaloids. And, like atro- pine, cocaine in decompositions is liable to form quite simple pyridine compounds, showing a direct relation to the pyridine series. The saponifieations of certain other well-known alkaloids, by digestion with alkali, or with acid, or with water, as stated in each instance, may be compared by the following equations. When the change is effected by acids the produced alkaloid is left in a salt ; but when by an alkali, the produced acid is left in a salt. Ecgonine unites both with acid and with alkali. C 17 H 23 NO 3 (atropine) + H 2 O=C 8 H 15 NO (tropine) + C 9 H 10 O 3 (tropic acid). C 33 H 43 NO 12 (acpnitine)+H 2 O:=C 26 H 39 ]TO 1]L (aconine)+C 7 H 6 O 2 (benzoic acid). C 17 H 01 NO 4 (cocaine) + 2H 2 0=C 9 H 15 NO 3 (ecgonine) + C 7 H 6 O 2 +CH 4 O (meth. ale.) C 22 H 23 NO 7 (narcotine) -(- H 2 O=C 12 H 15 lSrO 3 (hydrocotarnine) -j-C 10 H 10 O 5 (meconine). C 32 H 49 NO 9 (cevadine) + H 2 O=C 27 H 43 ]S"O 8 (cevin) + C 5 H 8 O 2 (methylcrotonic acid). OwHesNO^ (veratrine) + H s O=C 88 H 45 N0 8 (verin) + C 8 H 10 O 4 (veratric acid). C 17 H 19 NO ? (piperine) +H 2 O=C 5 H U N (piperidine) +C 12 H 10 O 4 (piperic acid). Except narcotine (and possibly piperine) the saponifiable alka- loids here given are the representative medicinal constituents of the plants wherein they are found : cevadine being the most active constituent of veratrum veride, as veratrine is of cevadilla. The acids formed in the saponifications are aromatic compounds easily reduced to benzoic acid, with the exception of methylcro- tonic acid. Yield of alkaloids from coca leaf. By the process given following, Dr. Squibb obtains from well preserved lots of the dried leaves, shipped in bales, from 0.5 to 0.8 per cent, of alkaloid. Dr. Lyons obtained from the dried leaves, shipped in bales, 0.65 to 6.75, and even 0.80, per cent, of alkaloid. The alkaloidal product of these assays consists, when good leaves are taken, in the greater part of cry stall! zable alkaloid, though in some part of amorphous coca alkaloids. The crystallizable alka- loid is probably nearly all cocaine ; at least both ecgonine and benzoyl-ecgonine must be pretty surely left behind in each meth- od of assay, by the free solubility in water and the very slight solubility in ether of both of these alkaloids. 172 COCA ALKALOIDS. It is noteworthy that all the coca alkaloids, natural or pro- duced, so far as reported, are readily soluble in water as free al- kaloids, save only cocaine itself. Also that ecgonine and ben- zoyl-ecgonine are nearly insoluble in ether, which dissolves cocaine abundantly. The solubilities are further shown here: THE FREE ALKALOID. THE HYDB1 iCHLORIDE. Water. Ether. Water. Ether. CrystallizaUe : Cocaine "Very slight Soluble Soluble Insoluble Ecgonine Soluble Near in sol Soluble Benzoyl-ecgonine. . . . Amorphous : "Amorph. alkaloids." Hygrine Soluble. Not freely. Soluble * Near insol. Soluble. Soluble Soluble. Soluble. Soluble Insoluble. AMORPHOUS COCAINE. Cocainoidine. Cocaicine. The qua- litative reactions and properties of the amorphous alkaloid ob- tained with cocaine in its preparation are designated by A. B. LYONS 1 as follows : The compounds are very difficult to crystal- lize. The precipitate produced in the hydrochlorate by alkalies did not crystallize at all (compare 'below under Cocaine, d), neither that by picric acid. In very dilute solutions (1 to 5000) gold chloride produced after some time minute prismatic crys- tals, wholly unlike in general appearance the fern-like forms from the crystallizable salt. Platinum chloride produced a few rosette- like aggregations. On evaporation the amorphous alkaloid (pro- bably not free from non-alkaloid al matter) invariably turned dark, and 'if the salt was evaporated quite to dryness it was found to be imperfectly soluble in water. ECGONINE. C 9 H 15 NO 3 =il85 (LossEN, 1865). Crystallizes with 1H 2 O. A pyridine derivative nearly related to the tro- pines. The alkaloidal body obtained by saponification of Cocaine. It crystallizes from absolute alcohol in monoclinic prisms. Melts at 198 C., with browning, and decomposes at higher tempe- ratures. Has a slight bitter-sweet taste. It is freely soluble in water, soluble in alcohol, sparingly soluble in absolute alcohol, and insoluble in ether. In reaction it is neutral. It forms slightly crystallizable salts with hydrochloric and other acids, 1885: Am. Jour Phar., 57, 475. ECGONINE.HYGRINE. 1 73 gummy compounds with alkalies, and a crystallizable salt with barium. The hydrochloride of ecgonine appears in a yellowish, crystalline mass, freely soluble in water and (Calmels and Gros- sin) in alcohol. Slightly soluble in alcohol (Lossen). Ecgonine platinochloride, (C 9 H 15 NO 3 . HCl) 2 PtCl 4 , is soluble in water; less soluble in alcohol. The aurochloride is soluble in water and in alcohol. Barium salt of ecgonine (CALMELS and GOSSIN, 1885) forms slender, prismatic crystals, freely soluble in water and in alcohol, slightly soluble in ether. When the barium salt of ecgonine, as obtained, with barium benzoate, by saponifying cocaine with baryta, is distilled, an isotropine (C 8 H 15 NO) is obtained (Calmels and G.) It will be observed that ecgonine, by loss of CO 2 , presents the elements of a tropine. BENZOYL-ECGONINE. C 16 H 19 NO 4 =: 289. Crystallizes with 4H 2 O. Union of ecgonine with benzoic acid, the elements of H 2 O being eliminated: C 9 H 14 E"O 3 . C 7 H 5 O. (W. MERCK, 1885. 1 Z. H. SKRAUP, 1885. a ) Found as a by-product of cocaine man- ufacture from coca leaves. Crystallizes in transparent flat prisms. When quickly heated melts [hydrated ?] at 90 to 92 C., solidifies again and then melts [anhydrous?] at about 192 C. (Skraup). Melts, with browning, at 188.5 to 189 C. (Merck). Soluble freely in water, sparingly in alcohol, nearly insoluble in ether. It forms salts : the sulphate and acetate crystallize in prisms. The aurochloride, C 1 gH 19 ^N"O 4 . HC1 . AuCl 3 , forms yel- low scales, sparingly soluble in water, soluble in alcohol. On heating benzoyl-ecgonine with methyl iodide and an equal volume of methyl alcohol, the synthesis of cocaine is obtained : C 18 H 19 N0 4 +CH 3 I = C 17 H 21 N0 4 . HI. AN ANHYDRIDE OF ECGONINE. C 9 H 13 NO 2 . (CALMELS and GoS- SIN, 1885.) When ecgonine is heated with moderately strong sulphuric acid, an alkaloid is obtained which forms readily crys- tallizable salts both with acids and with alkalies, less soluble than corresponding ecgonine salts the barium salt having the compo- sition BaO . (C 9 H 13 NO 2 ) 2 , and its hydrochloride forming stellate groups of prismatic needles. The platinochloride forms feathery groups of crystals, very soluble in water and in alcohol. HYGRINE. A volatile alkaloid found with cocaine in coca leaves (LOSSEN, 1865 3 ). A thick, oily liquid of a pale yellowish 1 Ber. d. chem. Ges., 18, 1594; Jour. Chem. Soc., Abs., 997. *Monatsch. Chem., 6, 556; Jour. Chem. Soc., Abs., 1249. Also see PAUL, 1885: Phar. Jour. Trans., [3], 16, 325. 3 W6HLEB and LOSSEN: Ann. Chem. Phar., 121, 374; 133, 352. LOSSEN: "Dissertation." 174 COCAINE. color. Distils slowly with water ; distils alone between 140 C. and 230 C. It has an odor resembling trimethylamine, and a burning taste. Had no poisonous effect on rabbits. It is solu- ble in water (not in all proportions) ; freely soluble in alcohol and in ether. It unites with acids, forming salts. The hydrochloride forms deliquescent crystals. It is precipitated by iodine in po- tassium iodide solution, mercuric chloride, silver nitrate, and stannous chloride. COCAINE. C 17 H 21 NO 4 =303 (LossEN, 1865). Chief alka- loid of the Erythroxylon coca leaf (NnatAKH, 1860). For the yield from the leaf, and for chemical constitution and relations of the alkaloid, see above under COCA ALKALOIDS. Cocaine is identified by its effect on the tongue or eye (J), and the agreement of its precipitations (d). It is distinguished from ecgonine or benzoyl-ecgonine by solubilities of the free al- kaloid in water and in ether (g). Its separations are effected by use of ether, etc., vxAfrom coca leaf by several assay methods (e). ^stimation^ gravimetrically or volumetrically (f) ; also by ob- taining limits of precipitations (d). Tests for impurities (g). a. Cocaine crystallizes in monoclinic prisms, obtained from concentrated alcoholic solution. It appears either in colorless, distinct crystals or in a white, crystalline or granular powder. The alkaloid imperfectly purified from the leaf, or that from in- jured leaves, is more or less dark colored, and contains amorphous coca alkaloid, partly liquid. Cocaine, free alkaloid, is often pre- sented as an amorphous powder, cohering like magnesia (SQUIBB), and not quite white. The salts are more crystallizable than the free alkaloid. The hydrochloride crystallizes with a general ap- pearance like that of the free alkaloid ; from concentrated alco- holic solution in short, rough prisms, among which rhombic plates may be found under the microscope ; from dilute alcoholic solu- tion long, brittle needles are obtainable ; from aqueous solution, silky-lustrous needles. The hydrobromide crystallizes in color- less, radiating needles. The hydrochloride is the chief form of the alkaloid in general use. It is furnished in different styles, including hydrated crystals of good size, minute anhydrous crys- tals, granules of obscurely crystalline powder, and amorphous powder. Cocaine melts at 98 C. (LOSSEN). More strongly heated it vaporizes with decomposition of the greater portion. The hydro- chloride parts with its water of crystallization (2 aq.) at or below 100C. COCAINE. 175 1). Cocaine lias a bitter taste, and is without odor. Its de- composition products in mould y coca leaves are said sometimes to present a tobacco-like odor. Cocaine is distinguished by an intense local anaesthetic and blanching effect upon the mucous membrane, giving on the tongue a characteristic insensibility, a sudden cessation of feeling, lasting but a few minutes (NIEMANN, 1860). One drop of a four per cent, solution (about 0.04 grain) suffices to blanch the conjunctiva of the eye; 1 and by the" same application to the tongue (previously rinsed clean) lirst the slight bitterness and then a decided numbness are perceived. These effects are evanescent, unless 'the application be repeated. The anaesthesia of an eye, for surgical operations, can be accomplished by the application of " 5 drops of a 4 per cent, solution in two installations ten minutes apart" (E. E. SQUIBB, 1885). Dilatation of the pupil of the eye is a general effect of cocaine, either ap- plied to the eye or administered to the system. This effect is said not to be invariable ; certainly the midriasis from cocaine is very far from reaching the intensity obtained by the atropine group of alkaloids. NIKOLSKY obtained with warm-blooded ani- mals a constant widening of the pupil when under the action of cocaine. Dilatation was also observed with frogs. The fatal dose of cocaine was found for dogs, by DANINI (1873), 0.15 to 0.30 gram (2J- to 4f grains). In rabbits the hy- podermic administration of 0.1 gram (1J grain) per kilogram of body- weight caused death in a few hours, sometimes in a few minutes (v. ANREP, 1880). The hypodermic introduction of about -gV grain caused dangerous symptoms in a girl of 12 years (Ther. Gazette, Feb., 1886, p. 88). c. Cocaine is very slightly soluble in water, soluble in alco- hol, ether, chloroform, benzene, petroleum benzin, disulphide of carbon, and in fixed and volatile oils. The salts of cocaine are soluble in water and in alcohol. The hydrochloride dissolves in less than its own weight of water ; is freely soluble in alcohol, less readily in absolute alcohol and in chloroform, and is practi- cally insoluble in ether, in petroleum benzin, and in fixed and volatile oils. Cocaine solutions have a strongly alkaline reaction with litmus (not affecting phenol-phthalein), and form definite salts. The hydrochloride and hydrobromide are neutral in reac- tion. Hydrochloride crystals are permanent in the air ; obtained 1 This specific use of cocaine was first announced by Dr. Carl Roller, of Vienna, at Heidelberg, in September, 1884 (London Lancet, 1884, p. 990). (v. ANREP, 1880; SCHROFF, 1862.) The extensive use of cocaine as a local anaes- thetic rapidly followed the announcement of Dr. Roller. 176 COCAINE. in presence of water they have two molecules (9.6 per cent.) of water of crystallization, but anhydrous crystals can be obtained from alcohol. Hydrobromide crystals also contain two molecules (8.57 per cent.) of water of crystallization. Cocaine citrate is hygroscopic and does not easily crystallize. The oleate of cocaine readily crystallizes, and dissolves in oleic acid or in oils (LYONS). Aqueous solutions of cocaine salts after a few days suffer decom- position of the alkaloid, with vegetable cell growths, unless pre- served by an antiseptic (SQUIBB, 1885). Neutral solution of the hydrochloride in freshly prepared distilled water, when secluded from the air in glass-stoppered bottles, keeps unchanged several months (POLENSKI, 1885). d. The local physiological test upon the tongue, and then upon the eye, for the (evanescent) effects above detailed, may be resorted to for identification. If the material tested be known only as alkaloidal matter, safety requires that the substance should be obtained in neutral solution of definite strength, the prelimi- .nary trials being made with such attenuations as would be harm- less in case of the presence of aconitine or atropine, or other agent of most intense action. In the experiments of DR. SQUIBB (1887) a distinct impression, just short of numbness, was ob- tained by three out of four persons by holding one minute in the mouth 3-^5- grain (0.00063 gram) of cocaine in solution in one minim of water, the mouth having been previously rinsed. When the solution of alkaloid was dried on filter-paper, the limit of re- cognition was found to lie at -f^ of a grain of the alkaloid, held in the mouth one minute (Ephemeris, 3, 918). Mayer's solution gives a precipitate with cocaine hydrochlo- ride. According to LYONS (1885) 1 the precipitate is visibly pro- duced in one drop of a solution of the salt in 12500 parts of water. Precipitates in very dilute solutions are formed by iodine in potassium iodide solution, by phosphomolybdate, and by tannin. Mercuric chloride causes a precipitate in quite concentrated solutions, with a resulting red color like that of atropine (FLUCKIGER, 1886). . Caustic alkalies, including ammo- nia, added to moderately dilute solutions, cause a precipitation of the free alkaloid. The precipitate has a crystalline structure, either from the first or after standing a short time. Excess of ammonia does not dissolve the precipitate, but any considerable excess of fixed alkali will soon bring about saponification of the alkaloid, with partial solution. The alkali carbonates and l>i- 1 Am. Jour. Phar., 57, 473. COCAINE. 177 carbonates cause precipitation. Platinum chloride and Gold chloride produce crystalline precipitates, the former reaction re- quiring moderate concentration. Cocaine has a good degree of reducing power. Ferricya- nide paper, prepared by wetting blotting-paper with a drop or t\vo of a fresh mixture of equal volumes of potassium ferricya- nide and feme chloride solutions, on adding a drop or two of the alkaloid solution and shading from the light, gives reduction to the blue in the following ratio (CURTMAN, 1885 ') : With mor- phine in \ minute ; cocaine, 1 J minute ; brucine, 6 m. ; quinine, 7 m. ; cinchonine, 10 m. ; strychnine, veratrine, each 15 minutes. Permanganate of potassium is but slightly reduced at once, fully on standing or on boiling, and in concentrated cocaine solu- tions decinormal solution of permanganate produces a crystalline precipitate of cocaine permanganate, appearing under the mi- croscope when fresh in beautiful violet-red crystals, rhombic nearly rectangular plates, frequently grouped in rosettes. (F. GIESEL, 1886; A. B. LYONS, 1886). A brown residue of man- ganic hydrate is soon formed (see g). Saponification of cocaine was accomplished by LOSSEN (1865) with hydrochloric acid in hot digestion (100 C.), best in sealed tubes, continuing the digestion as long as the precipitation of benzoic acid is seen to increase. MACLAGEN (1885 *) caused a saponification with alcoholic potash, or the cocaine " was dis- solved in alcohol and strong solution of soda or potassa added," when " the odor of benzoic acid is quickly perceptible," soon disappearing. After a short time, if a little water be added, -the alcohol driven off by a gentle heat, and the liquid acidulated, a precipitate of benzoic acid is obtained. Ammonia appeared to effect no saponification. CALMELS and GOSSIN (1885) effected the saponification by barium hydrate, in sealed tubes, at 120 C. The products are ECGONINE, Benzoic Acid, and Methyl Alcohol : C 17 H 21 NO 4 +2H 2 O=:C 9 H 15 KO 3 -|-C 7 H 6 O 2 +CH 4 O. By boiling in water, especially by long hot digestion, cocaine suffers saponi- fication, and its solutions redden litmus (PAUL, 1886; FLUCK- IGER, 1886). e. Separations. Cocaine is removed from aqueous solu- tions of its salts by adding ammonia to liberate the alkaloid, avoiding an excess, and shaking out with ether, chloroform, ben- zene, or petroleum benzin. From ethereal solutions the alkaloid is taken up by slightly acidulated water, upon agitation. 1 Phar. Rundschau, 3, 252. 2 The American Druggist, 14, 23 (Feb., 1885). 1 78 COCAINE. Prom the coca leaves, the following process is used by LYONS :' Take 10 grams of No. 30 powdered coca leaves, or so much of this powder as will represent 10 grams of a sample of leaves carefully selected from toward the centre of the package. Place in a bottle of capacity of about 120 c.c., add 100 c.c. of a mix- ture of 95 volumes stronger ether and 5 volumes of a spirit of ammonia made by mixing 1 volume ammonia-water of sp. gr 0.9094 with 19 volumes absolute alcohol, stopper securely, and agitate well at intervals of half an hour for a day. Allow as nearly as possible 24 hours for the maceration : a perceptible loss of the alkaloid, doubtless due to the free alkali, results from ma- cerating over 48 hours. Take out quickly 50 c.c. of the clear ethereal liquid into a separator. If there are floating particles, filter through a small filter, and wash with least sufficient quan- tity of ether. Add in the separator 5 c.c. of acidulous water containing ^ by volume of sulphuric acid. Agitate well, allow the acid liquid to separate, draw the aqueous layer off into a bot- tle of the capacity of 30 c.c. ; add again in the separator 2-J c.c. of water slightly acidulated with sulphuric acid, shake out, leave to separate, and draw off ; and repeat this washing once or twice more, receiving all the aqueous portions together. To the whole aqueous liquid, in the bottle, add 10 c.c. of ether, agitate, leave at rest, pour off the ethereal wash-liquid, add in the bottle 10 c.c. of fresh ether, then gradually add a slight excess of dry carbonate of sodium, with care to avoid loss by effervescence, cork securely, agitate well but not so violently as to cause emul- sification, set at rest, and with a rubber- bulb pipette draw off the clear ethereal layer into a small tared beaker, to be now set in a warm place (about 45 C., 113 F.) While the ether is evaporat- ing wash with a second and third portion of ether, and wash with ether until a drop of the aqueous fluid, acidulated, and treated with a minute drop of Mayer's solution, gives not more than a slight milkiness. The residue left by evaporation of the ether is inspected, and dried at 100 C. to a constant weight. The al- kaloid obtained represents 5 grams of coca leaves. The percen- tage is obtained by dividing the milligrams of weight by 50. The assay of coca leaves is conducted by Dr. E. R. SQUIBB 2 as follows : Of the coarsely powdered leaves 100 grams are mois- tened with 100 c.c. of water containing 5$ of sulphuric acid, and packed moderately close in a cylindrical percolator. Using the same acid solvent, 500 c.c. of percolate are obtained, better by the help of a pump. The percolate is well mixed in a large 1 1885: Chicag Pharmacist, Sept. 2 Ephemeris, 3, 912 (Jan., 1887). COCAINE. 179 beaker with 50 c.c. of kerosene, when enough well-crystallized carbonate of sodium to saturate 500 c.c. of acid- water is gra- dually added, the requisite quantity having been previously de- termined by a trial upon 100 c.c. of the acidulated water. 1 Dur- ing four or five hours of digestion the mixture is repeatedly stirred. The kerosene is. drawn off by a separator or a small siphon. The extraction is continued with two additional por- tions each of 25 c.c. of kerosene. If a layer of emulsion appears it is drawn off separately, and stirred with asbestos, or sand, or dry filter- paper pulp, and the separated kerosene added to the larger portion. If the mixture have been shaken instead of stirred, the most of the kerosene will be found in emulsion. 2 The kerosene solution of alkaloid (100 c.c.) is shaken vigo- rously, in a separator, with two portions of 10 c.c. of the acid- water, and one portion of 5 c.c. of the same. Now to the 25 c.c. of cocaine sulphate solution 10 c.c. of stronger ether are added, in a separator, and well shaken, then a moderate excess of sodium carbonate crystals is added. After the effervescence the mix- ture is shaken, the ether separated, and two more washings are made, each with 10 c.c. of the ether. The collected ether, per- fectly free from aqueous solution, is evaporated in a weighed beaker of at least three times the capacity of the ether. The alkaloid will be in form of a light amber- colored varnish. As soon as the ether is wholly evaporated the beaker is cooled and weighed, and the tare subtracted. The highest yield obtained by Dr. Squibb has been 0.892$. On standing 24 to 48 hours the varnish-coat of alkaloid is converted into a white, crystal- line crust, withou t change of weight. TKUPHEME (1885) recommends an assay plan as follows : The coca leaves are exhausted with ether ; after recovering the ether by distillation, the residual extract is treated with boiling water, mixed with magnesia, and dried. The dried mass is exhausted with amyl alcohol. In all assay operations the continued action of hot acids, or hot fixed alkalies, or even of hot water, is to be avoided, as liable to cause saponification or other alterations. f. Quantitative. Cocaine is estimated gravimetrically by 1 Excess of alkali is required, and sufficient excess is obtained by following the direction. 2 Further assurance of the complete separation of the alkaloid is obtained by adding a little more sodinm carbonate and shaking out with ether (25 c.c.), when the residue by evaporation of the ether may be tested on the tongue for i8o COCAINE. drying at near 100 C., and weighing as anhydrous alkaloid (see a). Volumetrically, cocaine may be estimated with Mayer's solution, standardizing the reagent by a known solution of the alkaloid, and correcting the result by parallel titrations of the known solution and that under estimation, concentration being the same in each (p. 45). g. Tests for purity. For the next revision of Ph Germ, the following requirements for cocaine hydrochloride are pro- posed : ' A white, crystalline powder of faintly acid reaction, somewhat bitter taste, and causing a very characteristic insensi- bility of the tongue, intense but transient. . . . Concentrated sulphuric acid dissolves it with some foaming but without colora- tion, and no color is caused by solution in nitric or hydrochloric acid. The salt should dissolve in twice its weight of cold water ; and when heated on platinum foil should leave no residue. The Br. Ph. designates that the salt " dissolves without color in cold concentrated acids, but chars with hot sulphuric acid." Also, " the solution yields little or no cloudiness with chloride of barium or oxalate of ammonium." Some incidental impuri- ties give yellow to red and rose-red colors with the cold sul- phuric acid, which is said to be a severe but quite general test of purity. Tests by solubilities (see table under Coca Alkaloids) of the free alkaloid. May be applied to cocaine salts by treating with dilute ammonia, avoiding much excess, draining, and washing with a very little water, when the precipitate may be dried at a gentle .heat and used for the tests. The free cocaine should require not less than 1200 to 1800 times its weight of cold water to dissolve it (absence of any considerable proportions of ecgonine or ben- zoyl-ecgonine). Should also be completely soluble in ether. But for this test cocaine salts and any ammonium salt should be well removed. According to the excellent investigation of DK. SQUIBB (1887, Ephemeris, 3, 906), the cocaine of commerce consists mainly of a larger portion of readily crystallizable salt with smaller varying proportions of difficultly crystallizable salt. The latter portion was found not to be inferior in physiological power. Further, solubility in chloroform was found a trusty indication of the pro- portion of the less crystallizable part, this requiring less chloro- form to dissolve it. 0.4 gram of perfectly crystallizable hydro- chloride takes 9 c.c. of chloroform of not less than 1.47 sp. gr. to dissolve it. The salt is precipitated from chloroformic solutions 1 The pharmacopoeial commission of the Deutschen Apotheker-verein, 1885. COLORING MATERIALS. 181 by adding ether. The same investigator reports the " perman- ganate test of Giesel to be hypercritical and often fallacious." CODAMINE. See OPIUM ALKALOIDS. CODEINE. See OPIUM ALKALOIDS. COLORING MATERIALS. The scope of this work does not permit giving the descriptive chemistry l of the dye-stuffs and pigments in use at present. Several systematic methods of analy- sis of coloring matters, recently contributed by color chemists, are presented in the following pages. To these schemes for qualita- tive analysis some notes of description or of definition of color compounds are added, and references to convenient sources of descriptive literature are given. A list of published schemes of analysis of coloring matters is here offered, with the assurance that it is by no means a complete bibliography of methods of qualitative work upon colors. THE CHEMICAL DETERMINATION OF COMMERCIAL COLORING MATERIALS. By treatment of the dye-stuffs alone, or of tissues colored by them. For Blue coloring matters: vegetable blues, coal-tar blues, and prussian blue. W. STEIN, 1869: Polyt. Centralbl, p. 1023; Zeitsch. anal. Chem,, 9, 128. For Red coloring materials, mainly those of vegetable origin. W. STEIN, 1870. Given on pages 188 to 192 of this work, with addition of notes and refer- ences. A ready method. For Violet colors, both those of vegetable origin and coal-tar derivatives. W. STEIN, 1870: Polyt. Centralbl., p. 1504; Zeitsch. anal. Chem., 10, 375. 1 The following references may be of some service to those in search of literature upon the descriptive chemistry of color substances: POST'S " Chernisch-Technische Analyse," Braunschweig, 1882. Pages 963 to 997: " Farbstoffe und zugehorige Industrieen." Natural organic colors; ar- tificial colors, both mineral and organic. BOCKMANN'S " Chemisch-Technische Untersuchungs-Methoden," Berlin, 1 884. Pages 245 to 336 : ' ' Theerf arben , " von Dr. R. NIETZKI. Pages 337 to 343 : " Ultramarin," von Dr. E. BUCHNER. HAGER'S "Pharra. Praxis," Erganzungsband, 1883. Pages 951 to 987: "Pigmenta." SLATER'S "Colors and Dye- Wares," London, 1879, pp. 217. Serviceable only for commercial definitions. CROOKES, 1882: "Dyeing and Tissue Printing," London. ''Bleaching, Dyeing, and Calico Printing." Published by J. and A. Churchill, London, 1883. With an account of Dye-Wares. ROSTER, 1882: " The Hygiene of Coal-Tar Colors," Heidelberg. A full re- view in Chem. News, 48, 20. WITZ, Relation of Colors to Cellulose, 1884: Ding. pol. Jour., 250, 271; Jour. Soe. Chem. 2nd., 3, 206. 1 82 COLORING MATERIALS. For Greens and Yellows, from vegetable sources and from coal-tar. W. STEIN, 1870: Polyt. Centralbl., p. 1055; Zeitsch. anal. Chem., 10, 115. For all the Colors, mainly those of coal-tar production. OTTO N. WITT, 1886. In the next following pages, with addition of brief definitions of commer- cial names. A quite elaborate scheme, presented by a chemist well known for important contributions on the chemistry of coal-tar dyes. for Colors in general, mostly of vegetable origin. F. FOL, 1874. Given in the following pages. For the Coal-Tar Colors, as fixed upon Silk, Wool, and Cotton. N. BIBANOW, 1875: Monit. scie ntif., [3], 4, 509; Zeitsch. anal. Chem., 14, 106. For Coal-Tar Colors and Vegetable Colors, as fixed upon fabrics. J. JOFFBE, 1882: Monit. scientif., [81 12, 959; Zeitsch. anal. Chem., 22, 610; Chem. News, 46, 217 (in full); Jour. Soc. Chem. Ind., I, 447 (in full). For Coal- Tar Ztye-S/M/s. BOCKMANN'S ' Chemisch-Technische Untersuchungs- Methoden," 1884, pp. 328-333. For the Principal Colors, taken as free dye-stuffs or in solutions. DRAGEN- DORFF, in "Gerichtl. Chem. Organ. G'ifte," 1872. Given in this work in pages following. Presents a method of separation by the immiscible sol- vents. For Colors in General, fixed upon dyed and printed fabrics. CROOKES'S "Dye- ing and Tissue Printing," 1882,' p. 399. For Coal-Tar Colors. J. SPILLER, 1880: Chem. News, 42, 191. WITT'S PLAN OF QUALITATIVE ANALYSIS OF COMMERCIAL COLOR- ING MATTERS/ chiefly Coal- Tar Dyes. A. Red Coloring Matters. I. The color is insoluble in cold, and with difficulty soluble in hot water, but it is easily dissolved by alcohol. 1. The alcoholic solution is salmon-colored, without fluorescence. The so- lution in strong sulphuric acid is reddish-violet. Naphthalene-Carmine (Kar- min-naphte) 2. The alcoholic solution is reddish blue, and shows an intense orange-red fluorescence. Examined with the spectroscope, it shows a wide absorption- band, which completely extinguishes the yellow and green portions of the spec- trum. 2 The solution in sulphuric acid is greenish-gray. On diluting, the solu- tion first turns red, and then a reddish-violet precipitate is formed. Magdala- Red (Naphthalene- Red. Rosenaphthalene). 3. Insoluble in cold water, slightly soluble in hot. The behavior of the al- coholic solution is precisely similar to magdala-red, only the absorption-band is more to the right, so that a portion of the yellow remains visible. The solu- tion in sulphuric acid is colorless; on diluting, each drop of water as it enters the liquid causes a deep red color. By the further addition of water the whole liquid is colored a deep magenta-red. This reaction is different from that of magdala-red. Quinoline-Red. 4. The alcoholic solution fluoresces in a similar manner, but the fluores- cence is greener. The solution in concentrated sulphuric acid is lemon-colored to orange, and shows no striking change of color on the addition of water. 'Otto N. Witt, 1886: The Analyst, n, 111 (translated by J. T. Leon). Not including anthracene products. 2 A good pocket spectroscope, which, with ordinary adjustment, will show Fraunhofer's lines, is sufficient for the examinations in this scheme. WITTS PLAN OF ANALYSIS. 183 Eosins (tetrabromfluoresceins, C2oH 8 Br 4 5 ), soluble in alcohol (to be distin- guished from each other by the difference in tint of dyed specimens). 5. The alcoholic solution is a dull bluish-red. The solution in strong sul- phuric acid is green, on dilution becoming bluish-red. Rhodidine (Induline of the naphthalene group). II. The coloring matter is more or less soluble in cold water, easily soluble in boiling water. a. The solution is precipitated by soda. Basal coloring matters. 1. The solution in water is bluish-red, changing on the addition of hydro- chloric or sulphuric acid to a yellowish- brown. The red color is restored by the addition of sodium acetate. By "boiling wool in a dilute ammoniacal solu- tion which has only a slight red color, it is dved a deep red. Zinc-dust per- manently decolorizes the aqueous solution. The solid is either in the form of green crystals or has the appearance of a green metallic powder, which dis- solves in sulphuric acid to a yellowish-brown solution. Magenta (Fuchsin, Ro- saniline monacid salts, p. 191). 2 The solution is bluish-red. Ammonia gives an orange-colored, flocculent precipitate, which dissolves in ether to a red solution with a red fluorescence. The solution in sulphuric acid is green; on diluting with water the color changes to blue or violet, and finally to red. Toluylene-Red (CislJieN^ (known in commerce as neutral red, generally very impure, and therefore not giving pure colors in the above reactions). b. The solution is not precipitated by soda. Acid coloring matters, or basal colors of the Saffranin class of compounds (type C 18 H 14 N 4 ). 1. On the addition of soda to the aqueous solution a change of color takes place, the solution becoming colored an intense blue. The solution in sulphuric acid is a brownish-yellow, becoming somewhat redder on dilution. Oallein (Pyrogallol-phthaleiti, C 3 o H , 7 ). 2. By the addition of alcohol to the aqueous solution a distinct yellowish fluorescence is produced. The addition of acid produces no precipitate. Zinc- dust decolors the solution, but on contact with air the original color is imme- diately restored. The solution in sulphuric acid is green, and, on diluting, first becomes blue and finally red. Saffranin and Saffranisol (to be distinguished from each other by the difference in tint of dyed specimens). 3. The aqueous solution is a pure red and shows a greenish-yellow fluores- cence, which becomes more distinct the more it is diluted. The addition of acid gives an orange-yellow precipitate, which is soluble in ether. The ethereal solution is a pure yellow, without fluorescence. The solution in sulphuric acid is yellow. Eosin (tetrabromfluorescein). 4. The aqueous solution is more of a bluish-red and shows no fluorescence. Acids give a straw-colored precipitate, soluble in ether to a liquid of the same color. Concentrated sulphuric acid gives a golden-yellow solution. Zinc-dust decolors the ammoniacal solution. If the colorless solution be dropped on blot- ting-paper, it acquires an intense bluish-red color by contact with the air. Eosin- Scarlet , bromo-nitro-fluorescein, C2oH 8 Br 2 (N02J 2 05. 5. The solution is bluish-red, without fluorescence. Acids give an orange- yellow precipitate soluble in ether. Strong sulphuric acid gives an orange- yellow solution. Zinc-dust and ammonia decolor the solution, and the color is not restored by contact with air. Phloxin. Bengal-Red. (Eosins, to be distin- 1 84 COLORING MATERIALS. guished from each other by the difference in tint. Bengal-red bears more to the blue.) 6. The hot-concentrated aqueous solution solidifies, on cooling, to a jelly. The addition of acids causes a brown, flocculent precipitate. On warming with zinc-dust and ammonia the solution first becomes a bright yellow and then colorless. Concentrated sulphuric acid dissolves it to a grass-green solution. On dilution the liquid first acquires a bluish tint, and then a dirty brown pre- cipitate comes down. Biebrich-Scarlet (Double Scarlet. From amido-azo- benzene sul phonic acids with naphthols). 7. Barium chloride gives in an aqueous solution a flocculent red precipi- tate, which, on boiling, suddenly becomes crystalline and acquires a deep violet-black color. The solution is indigo-blue, turning violet and red on the addition of water. Crocein-ticarlet, 3B (Ber. d. chem. Ges., 15, 1352). 8. t The aqueous solution is colored a bright blue on the addition of a minute quantity of acid. Cotton-wool boiled in an aqueous solution, either with or without the addition of soap, is dyed a fast red. The solution in sulphuric acid is slate-colored, and this tint does not change on diluting. Congo-Red. 9. The hot aqueous solution solidifies on cooling, when there appears a sepa- ration of shining, bronze-colored crystals. The solution in strong sulphuric acid is violet, and diluting it with water causes a brown precipitate. Xylidine- ponceau (Xylidine-red, from alpha-naphthol-sulphonic acid, D. P. 26012). [Kichter's Organic Chemistry, Philadelphia, 1886, p. 453.] 10. The concentrated aqueous solution, mixed with magnesium sulphate, deposits, on cooling, long, shining crystals of the magnesium salt. The solution in sulphuric acid is violet. Wool is dyed by it a brilliant scarlet. Orocein- Scarlet, IB Extra (formed by the action of diazo-naphthionic acid on crocein- beta-naphthol-sulphonic acid). 11 The aqueous solution gives, with chloride of calcium or barium, an amorphous, flocculent precipitate. The solution in concentrated sulphuric acid is rose-red or carmine, and on diluting it a brownish-red precipitate comes down. Coloring matters from beta-naphthol-disulphonic acid, to be distin- guished from each other by the difference in tint of dyed samples: Ponceau R y 2R, 3R. Anisol-Red, coccin. (D. R P. 3229). [Ridker's Organic Chemistry, Smith's edition, p. 469.] 12. Wool is dyed magenta-red. Chloride of calcium gives, in an aqueous solution, a crystalline precipitate. The solution in concentrated sulphuric acid is bluish-violet, becoming red on diluting. Acid Azo-Kubin (D. R. P. 26012). 13. The color of the soliltion is a deep brownish-red. Wool is dyed the same color. The solution in sulphuric acid is blue; the addition of water gives a yellowish- brown precipitate. The hot-concentrated aqueous solution gives, on the addition of a drop of saturated soda solution, a precipitate of the sodium salt in the form of brown, pearly plates. Roccellin (Echtroth). [Post's " Chem. Tech. Anal.," p. 983.] 14. Chlorides of calcium and of barium give a flocculent, amorphous pre- cipitate. The solution in concentrated sulphuric acid is of an indigo-blue. Bordeaux-Blue (D. R. P. 3229). [Diazonaphthalin-beta-naphtholdisulpho- nate.j 15. The aqueous solution has a fine bluish -red color, which is completely removed by caustic soda, and is again restored by acetic acid. Acid Magenta [sodium rosaniline sulphonate]. B. Yellow and Orange Coloring Matters. I. The coloring matter is insoluble in cold water, and either totally or very nearly insoluble in hot water. On the other hand, it is soluble in alcohol. WITTS PLAN OF ANALYSIS. 185 1. The solution is lemon-colored. The color is either unaltered or slightly deepened by the addition of acids or alkalies. Chinophtalon. [Chimaphilin.] 2. The color of the solution is golden yellow. It is unaffected by acids. It is turned a deep brownish-red by alkalies and by boracic acid. Curcumin dye (Turmeric). 3. The color of the solution is golden-yellow. The addition of hydrochloric acid produces a red color. Amyl nitrite added to the hydrochloric acid solution produces no change of color on boiling, nor is nitrogen gas given off. Dime- thylamido-azubenzol (formerly used for coloring artificial wax from ozokerite). 4. Reactions similar to 3, except that arayl nitrite produces a change of color and a small quantity of nitrogen is given off. Amido-azobenzol, CiaH,N 2 .NH 2 . II. The coloring matter is soluble in boiling water. Strong sulphuric acid dissolves it without any great change of color. a. Caustic soda produces no precipitate. ACID COLORING MATTERS. 1. The solution is greenish yellow, having a very bitter taste. Alkalies color it a dark yellow. Unaffected by acids. Picric Acid ( Trinitrophenic Acid). 2. The solution is golden-yellow. Acids cause a white precipitate. Mar- tins- Yellow [Naphthalene- Yellow, C 10 H 5 (NO 2 ) 2 . ONa+H 2 0]. 3. The solution is golden-yellow; not precipitated by acids. On the addi- tion of chloride of potassium fine, needle-shaped crystals are precipitated. Acid Naphthol Yellow. 4. The solution is brownish-yellow, and shows a magnificent green fluores- cence, disappearing on the addition of hydrochloric acid, which also gives a precipitate. Fluorexcein (Uranin), Benzyl Fluorescein (Chrysolin). These two dyes can only be distinguished by a careful examination of the separated color- ing acids. [" Watts's Diet.," viii. 1606. Richter's Chemistry, Organic, Smith's edition, p. 629.] 5. The solution is golden-yellow, and not precipitated by acids. It is not decolored either oy zinc-dust and ammonia or by tin-salt and hydrochloric acid. Quinoline- Yellow. b. Caustic Soda gives a precipitate. BASIC DYES. 1. The precipitate with alkalies is yellow and is soluble in ether to a bright yellow solution, with a beautiful green fluorescence. Phosphine. [Chrysani- line, Ci 9 HiiN(NH 2 ) 2 , with a little magenta ] (This delicate ether test can also be used to detect phosphine in mixtures, as, for example, with grenadine, ma- roon, etc.) 2. The precipitate with alkalies is milk-white ; soluble in ether to a color- less solution with a greenish-blue fluorescence. Flavanttin, Ci 8 Hi 4 N 2 . 3. The precipitate with alkalies is milk-white. Ethereal solution colorless, without fluorescence. The yellow solution, when boiled with hydrochloric acid, gradually loses its color, and finally becomes colorless. Auramin. III. The coloring matter is soluble in water. The solution in concentrated sulphuric acid has a deep color. Azo-CoLoaiNG MATTERS. a. Soda produces a precipitate. 1 86 COLORING MATERIALS. 1. The color to wool is yellow. The aqueous solution solidifies, on cooling, to a bluish-red jelly. The sulphuric acid solution is brownish-yellow. C/try- soidin [diamido-azobenzene. BOCKMANN'S "Chem. Tech. Untersuch.," p: 308]. 2. The color given to wool is orange-brown. The solution does not soli- dify on cooling. The solution in sulphuric acid is brown. Vesnvin (Bis- marck-Brown, Manchester-Brown, or Phenylene-Brown). [Triamido-azoben- zene.] 5. Soda does not produce a precipitate. 1. The solution in sulphuric acid is yellow, becoming salmon-colored on diluting. The aqueous solution is yellow. Tropoeoline- Yellow. ! 2. The solution in sulphuric acid is yellow, changing to carmine-red on diluting. The aqueous solution is yellow, and the substance crystallizes out, on cooling, in glittering, golden scales. Dilute acids produce a reddish-violet pre- cipitate. Methyl-Orange. Ethyl-Orange. 3. The solution in sulphuric acid is violet, becoming on diluting reddish- violet, and at the same time forming a steel-gray precipitate. The aqueous so- lution is yellow, crystallizing out on cooling. Calcium and barium chlorides give a completely insoluble precipitate. Trop&olin 00. Diphenylamine-Yel- low. [SO,C 12 H 9 N a .NHCH 6 .] 4. The solution in sulphuric acid is bluish-green, becoming violet on dilut- ing, and forming a steel-blue precipitate. The aqueous solution is yellow; a crystalline precipitate separates from it on cooling. Barium chloride gives a yellow precipitate, which can be crystallized from a large quantity of water in shining plates. Jaune N (Yellow N). [BOCKMANN, p. 310.] 5. The solution in sulphuric acid is yellowish-green, becoming violet on diluting, and forming a gray precipitate. The aqueous solution is yellow, de- positing crystals on cooling. Calcium chloride gives an orange precipitate, which becomes red and crystalline on boiling. Luteolin. [C 2 oHi 8 . From protocatechuic acid.] 6. The solution in sulphuric acid is carmine, turning yellow on diluting. The aqueous solution is yellow, often cloudy, and becoming a deep red or violet on the addition of alcoholic soda. Citronin (Indian- Yellow. Curcumin. Pur- ree). [Buxanthin, Ci 9 H,60 10 .] 7. The sulphuric acid solution is a deep orange. On diluting no change of color takes place. The aqueous solution is orange ; on adding calcium chloride fine crystals of the calcium salt separate out. Orange G (D. R. P. No. 3229). 8. The sulphuric acid solution is a brown orange. No change of color oc- curs on diluting. The aqueous solution is yellow. A small addition of hydro- chloric acid causes a crystalline precipitate; excess of hydrochloric acid causes a separation of the free acid in gray needles. Tropmdlin (Chrysoin) [Resor- cin-azo-benzene sul phonic acid]. 9. The solution in sulphuric acid is carmine-red, becoming orange on dilut- ing. The aqueous solution is a reddish-orange ; chloride of calcium precipitates the fine red calcium salt, which crystallizes from a large proportion of boiling water in needles. Orange II. (Mandarin). [Tropceolin 000, No. II.] 10. The sulphuric acid solution is violet, becoming orange on diluting. The aqueous solution is orange-red, becoming carmine on the addition of caus- tic soda. Tropceolin 000 [No. I.] (Orange 1). GREEN COLORING MATTERS. 1. Soluble in water to an olive-brown solution. It easily dissolves in alka- lies to a grass-green solution. Concentrated sulphuric acid dissolves it to 1 On Tropoeolines in general see 0. N. WITT, 1879 : Jour. Chem. Soc., 35, 179. WITT'S PLAN OF ANALYSIS. 187 a dirty brown solution. CoruJein, C 2 oH 6 6 . [Post's "Chem. Tech. Anal.," p. 991.'] 2. Easily soluble in water, forming a bright green solution. Alkalies give it a rose-colored or gray precipitate. Strong acids color it yellow. Victoria- Green [Malachite-Gne-. C 19 H 13 N 2 (CH 3 ) 4 .OH. E. and O. FISCHER, 1878-79: Ber. d. chem. ties., n, 2095; 12, 79U; Jt.ur. Chem. >'oc., 36, 286. 787]. 3. Readily soluble in waier, forming a fine blue-green solution. Acids color it yellow. Alkalies decolor the solution without producing any precipi- tate. A specimen of stuff dyed turns violet when healed above 100 C. Iodine and methyl-green. [Hexamethyl rosaniline compounds. Bockmann's " Chem. Tech. Uritersuch ," p. 298.] 4. Easily soluble in water to a correspondingly pale green solution. Acids first deepen the color, and then change it to yellow. Alkalies completely de- color the solution. Silk and wool can only be dyed in an acid-bath (distinction from methyl-green, which will dye in a neutral bath). Dyed samples can be heated with safety for a short time to 150 C. Helvetia-Green. [Alkali-Green.] [Post's "Chem. Tech. Anal.," p. 987. Sodium sulphonate of malachite green.] BLUE COLORING MATTERS. 1. Quite insoluble in water, soluble in alcohol to blue solutions of various shades. Hydrochloric acid at first causes no change, but on standing minute, sparkling green crystals are precipitated. Caustic soda produces a brownish- red coloration. Concentrated sulphuric acid dissolves it, forming a brown so- lution. Rosaniline- Blue. 1 Diphenylamine-Blue." 1 (To be distinguished from each other by the difference in tint of dyed silk, especially with an artificial light ) 2. Insoluble in water. The alcoholic solution is colored red by the addi- tion of hydrochloric acid. Unaltered by alkalies. lodophcnin. [Derivative of Isatin, containing sulphur.] 3. Easily soluble in water. Hydrochloric acid gives a greenish precipi- tate. Caustic soda gives a violet-red precipitate. Zinc-dust reduces it, but the color is restored on contact with the air. It contains zinc. Mtthylene-Blue [Ci 6 Hi 9 N 3 S. Bockmann's " Untersuchungs-Methoden," p. 306] 4. Tolerably soluble in water. Acids color the solution yellowish-brown. Alkalies give a red-brown precipitate. Victoria-Blue. 5. Readily soluble in water. The solution is almost completely decolored by acids. Wool abstracts the coloring matter from the alkaline solution, and becomes colored a deep blue after washing with water and treating with dilute acids. Alkali-Blue E, and QB. 3 (Distinguished from each other by the dif- ference in tint.) 6. Easily soluble in water. Wool can only be dyed in an acid-bath. The aqueous solution is not precipitated by alkalies. Zinc-dust decolors permanently. Water-Blue (Wasserblau) R, QB. 4 1 " Aniline- Blue." "Insoluble Aniline-Blue." Spritblau. Triphenyl- rosaniline hydrochloride. Insoluble in water, sparingly soluble in alcohol, soluble in acetic acid or in aniline oil. The alkali sulphonates of triphenyl- rosaniline constitute "soluble blues," known as "alkali-blue" and "water blue," from the name of the solvent they require. 2 Diphenylamine-Blue is inferred to beatriphenyl-para-rosaniline. It forms a sulphonic acid soluble with alkalies. 3 "Alkali- Blue " is the mono sulphonic acid of triphenyl-rosaniline. It is not easily soluble in water alone, but on adding alkalies solution is readily ob- tained through formation of a sulphonate. " Water- Blue " consists of poly sulphonic acids of triphenyl-rosaniline, with (S0 3 H) 2 to (S0 3 H) 4 in the molecule. These sulphonic acids dissolve in water without the help of an alkali. 1 88 COLORING MATERIALS. 7. Easily soluble in water. Dyes only in an acid-bath. Zinc-dust and am- monia form a vat; that is, the color is restored on contact with air. The solu- tion is permanently decolored by boiling with dilute nitric acid. Indigo car- mine,. [Alkali salts of indigotin-disulphonic acid, as CieHeNaOa (SOsK) a ] 8. Insoluble in water, soluble in alcohol. Alkalies color the alcoholic solu- tion brownish-red to violet. Strong sulphuric acid dissolves it to a blue solu- tion. Induline R, QB. [Azo-diphenyl Blue.] (The more soluble the dye the redder the color.) 9. Soluble in water. Acids give a blue precipitate. The solution is colored red to violet by alkalies. Zinc-dust and ammonia form a vat. Dilute nitric acid does not decolor the solution, even on heating. Indulines soluble in water. (Distinguished from each other by difference in tints.) [Bockmann's " Unter- such.," p. 321.] 10. The commercial product is in the form of a gray paste. Soda solution gives a blue color on exposure to the air. Leukindophenol. 11. The commercial substance is a gray paste, which dissolves in soda with- out any blue coloration. On adding glucose, and boiling, crystals of indigo- blue separate out. Ortho-nitroplienylpropiolic Acid. VIOLET COLORING MATTERS. 1. With difficulty soluble in water; soluble in alcohol. Sulphuric acid forms a cinnamon-colored solution. Regina~Purple(Diplienyl-rosaniline). 2. Easily soluble in water. Alkalies give a precipitate. Hydrochloric acid colors the solution first green and then yellow. Methyl -Violet, R, 6B. Hof- mann's Violet. (Distinguished from each other by the difference in tint.) [Methyl-Violet is pentamethyl-rosaniline hydrochloride. It is the same as 4 ' Paris Violet." Hofmann's Violet is triethyl-rosaniline hydrochloride or hy- driodide. For description see Bockmann's " Untersuch.," p. 296.] 3. Not readily soluble in water. Alkalies give a violet precipitate. Con- centrated sulphuric acid dissolves it to a gray solution. On dilution the solution becomes successively grayish-green, sky-blue, bluish-violet, reddish-violet. Mauvein. (Parkin's Violet. Rosolane.} [C 2 7H 24 N4. By oxidation of aniline oil with dichromate and sulphuric acid. Perkin, 1856.] 4. Soluble in water. Acids give a blue precipitate; alkalies a reddish- violet precipitate. With zinc-dust and an acid, as well as in an ammoniacal solution, it forms an excellent vat. The solution in strong sulphuric acid is emerald-green, becoming sky-blue on diluting. Laufs Violet (Thionin). 5. Only soluble in boiling water. Hydrochloric acid colors the solution carmine-red. Sulphuric acid dissolves it to a blue solution, becoming red on diluting. Gallo-cyanin. 6 Soluble in water to a reddish-violet solution. The addition of alcohol causes a red fluorescence. Strong sulphuric acid dissolves it to an emerald- green solution; on diluting the color changes to blue or violet. Amethyst, Fuchsia, Oiroflee (Violet Saffranin Dyes}. [Saffranines are of the type C 18 Hi4N 4 . For a brief description of the group see Richter's Chemistry, Organic, Smith's ed., p. 469; Bockmann's "Untersuch.," p. 302.] Chemical Determination of Red Dye-Stuffs, according to Stein. 1 With fabrics, a small portion, of about one-fourth inch square surface, is treated in a test- tube with a few c.c. of the reagents directed. The resulting color solutions are subjected to the tests. I. The dye-stuff is warmed with ammonium sulphide. It turns more or less blue to greenish. "Aloes Dye" a mixture of Chrysammic and Aloetic acids used upon wool and silk. 'W. STEIN, 1870: Polyt. Centralbl.p. 616; Zeitsch.anal. Chem.,g, 520. STAIN'S SCHEME. 189 II. The dye-stuff is boiled with aluminium sulphate [filtered, cooled, and filtered again, GOPPELSRODER, 1878]. A. The solution turns red with a golden-green reflex. Madder colors (Note 1, following). B. The solution turns red without any reflex. On diluting it with an equal volume of sodium sulphite solution, it is (1) Bleached. Aniline reds, Sandal, Brazil-wood, Corallin, and Safflower. Add alcohol to 80 per cent, and boil. The solution (a) Colors decidedly (a) bluish- red Aniline-reds (Note 2, p. 191). (b) yellowish-red Sandal (Note 3, p. 191). (b) Does not color at all, or noticeably (Safflower, Brazil-wood, Corallin). Warmed with lime solution it assumes (a) no color Safflower (Carthamus) (Note 4, p. 191), (b) a red color (Brazil-woo'd and Corallin). Warmed with dilute sulphuric acid it becomes (a) orange-red Brazil-wood (Fernambuc}, (b) yellow and discolored Corallin (Note 5, p. 191). (2) Not bleached (by the sulphite). Archil, Lac dye, Kermes, Cochineal. Add alcohol to 80 per cent, and boil. It becomes (a) decidedly red Archil (Orseille) (Note 6, p. 192), (b) not red, or but slightly (Lac, Kermes, Cochineal). It is warmed by baryta solution. It takes (a) no color .Lac Dye, (b) colors (Kermes, Cochineal). It is warmed with lime solution ; colors (aa) brown-red Kermes (Coccus ilicis), (bb) violet Cochineal 1 (Coccus cacti). Note 1, upon Stein's scheme (above). The golden-green fluorescence, after hot treatment with aluminum sulphate, accord- ing to STEIN and others, is a distinction of natural madder-red from other reds, but is wholly due to the purpurin of the mad- der, and is not obtained with the alizarin. Since Stein's report artificial alizarin has gradually supplanted madder, and the latter is not now in extensive use. A brief description of alizarin and purpurin is here appended. Alizarin. C 14 H 8 O 4 = 240. Di-hvdroxy-aiithraquinone. C 6 H 4 : C 2 O 2 : C 6 H 2 (OH) 2 [OH : OH=l": 2]. "Madder-Red^ ^Alizarin-Red^ A product of anthracene, Ci 4 H 10 , of coal-tar, from which it is now chiefly obtained, by reactions of oxidation. Before 1869 it was wholly obtained from the root of the madder plant, Ru~bia tinctorum (Krapp* in the German). Natural and artificial alizarin are identical when each is perfectly purified. The natural alizarin comes from a glucoside of the plant, rube- rithric acid, C 26 H 28 O 14 . By boiling with dilute acids, also by a ferment in the madder root, two molecules of water are taken in, and a molecule of alizarin formed, with two of glucose. In orange-colored or yellow prisms, or in a brown paste. Melting 1 Upon the distinction between cochineal, kermes, and lac, three colors alike in most reactions, see Stein's report, Zeitsch. anal. Chem., 9, 522. COLORING MATERIALS. point, 282 C. (SCHUNCK). Insoluble in cold, slightly soluble in boiling water ; soluble in alcohol, ether, methyl alcohol, benzene (more readily on warming), or carbon disulphide. Alkalies and alkali carbonates dissolve it in water, the solution being violet by transmitted, purple by reflected light. Concentrated sulphuric acid does not decompose it. From the alkaline solutions acids precipitate it in reddish flakes ; and alum precipitates it with a red color. Alcoholic solution of alizarin, with acetate of copper or of iron, gives a purple precipitate ; with barium hydrate solu- tion, a blue precipitate. Sublimation is a serviceable means of examining alizarin. Natural alizarin contains Purpurin, and artificial alizarin con- tains Anthraquinone, as impurities. Alizarin itself begins to sublime at 110 C.; the two purpurins at 160-170 C. (SCHUNCK and ROEMER, 1880). The first sublimate from artificial alizarin, at temperatures below 140 C., will contain crystals of anthra- quinone with the long orange crystals of alizarin (GOPPELSRODER, 1877-78). In natural alizarin that is, when anthraquinone, hy- dro xy an thraquinone, and the anthraflavic acids are absent con- tinued sublimation at 140 C. removes the alizarin, which may thus be estimated by the loss. 1 The name alizarine, in commerce, has been sometimes applied to an extract of madder flowers ; and to Gerancin, a product of the action of strong sulphuric acid upon madder dye. Alizarin-Blue. C 17 H 19 1TO 4 . Formed from Alizarin-Orange by heating with sulphuric acid and glycerin. A bluish-violet paste, of about 10$ solid content. Soluble in alkalies with greenish-blue color, an excess of the alkali causing a precipitate. Colored red-brown by sulphuric or hydrochloric acid. Alizarin- Orange. Nitro- Alizarin. C 6 H 4 : C 2 O : C 6 H (NO 2 )(OH)o pTO 2 : OH : OH = 1 : 2 : 3]. In commerce as a yellow paste. Dissolves in sodium carbonate solution with yel- low-red ; in sodium hydrate solution with a red color; an excess of the caustic alkali precipitating the solution. Purpurin. C 14 H 8 O 5 =256. Tri-hydroxy- an thraquinone. C 6 H 4 : C 2 O 2 : C 6 H(OH) 3 [OH : OH . : OH=1 : 2 : 4]. Can be produced from anthracene. The isomerides Isopurpurin or anthrapurpurin, and Flavopurpurin or " yellow alizarin," have a limited employment in dyeing. Purpurin crystallizes in orange-red needles, with one molecule of crystallization-water. 1 SCHUNCK and ROEMER, 1880: Ber. d. c7>em. Ges., 13, 41; Jour. Chem. Soc., 38, 424. The same, 1877: Jour. Chem. Soc., 31, 665. Also, GOPPELSRO- DER, 1877: Ding, polyt. Journ., 226, 30; ZeitscJi. anal. Chem., 17, 510. STEIN'S SCHEME. 191 It is more soluble than alizarin, either in boiling water, al- cohol, or ether. The solution in alkali is red, in thin layers purple. A dilute alkaline solution soon bleaches in the air and light. With lime or baryta, in hot water, it forms a per- fectly insoluble lake. Boiling alum solution takes up purpurin abundantly, forming a yellow-red solution of strong fluorescence, whereby madder-red is distinguished in the scheme of Stein (p. 188). Note 2, upon the scheme of STEIN (p. 189). Aniline-reds. Salts of Hosaniline, C 20 II 19 N 3 = 301 (monobasic). The hydro- chloride and acetate, as mon.acid salts, constitute " Magenta," "Fuchsin," and u Roseine." The nitrate is prepared as " Aza- leine " and " Rubiiie." Kosanilines are triamido-toluyl-diphenyl methanes, the hydrated base having the structure (C 6 H 4 . NH )<> (C 6 H 3 CH 3 . NH 2 )C . OHi=C 20 H 21 ]S" 3 O. The base forms monacid salts of red color, triacid salts of a yellow color, and diacid salts of little stability. Commercial magenta or fuchsin appears in crystals of green metallic lustre. It is non- volatile, decomposing at about 220 C. It has a bitter taste. Rosaniline base is very slightly soluble in water, but melts in boiling water. The ordi- nary salts of rosaniline, the aniline-reds, are soluble in hot water and in alcohol, the solutions having a crimson-red color, and only impurities being left in insoluble residue. Addition of acids changes the color toward yellow, with formation of triacid rosaniline salts. Alkalies precipitate free rosaniline and destroy the color of the solution. Warmed with cupric chloride, aniline- reds show a blue color. They dye silk and wool a crimson-red, without a mordant. Rosaniline picrate forms fine red needles nearly insoluble in water. The tannate is insoluble in water, but soluble in alcohol, methyl alcohol, or acetic acid. Tannic acid precipitates rosaniline from aqueous solutions of its ordinary salts. Note 3. Sandal-red is turned brown by hot lime solution ; but its red color is intensified and finally changed toward blue by hot diluted sulphuric, hydrochloric, or acetic acid. Note . Saffiower-red (African Saffron, False Saffron). The action of the lime solution is to decolor through a change to yellow. Ammonium sulphide decolors it, more readily by addition of ammonium hydrate. The red color is restored by acetic acid. Note 5. Coraltin-red. Peonin. Prepared from Aurin or .Rosolic Acid. In violet powder or brown needles, soluble in water as a red solution having an alkaline reaction. With cupric 192 COLORING MATERIALS. chloride it is decolored to gray a distinction from aniline-red, which is turned blue in this test. Note 6. Archil. Orseille. Persio. The coloring matter derived from lichens of the genera Eoccella and Leconora. Vege- table acids in these lichens are converted into orcin, or orcinol. C 6 H3(CH 3 )(OH) 2 ^ [1 : 3 : 5], a di-hydroxy-toluene. With am- monia this gives rise to orcein, or " lichen-red," C 7 H 7 NO 3 , the chief constituent of archil dyes. Litmus and Cudbear also con- tain color derivatives of orcin, obtained from the lichens. Orcin is manufactured from toluene, as a source of orcein, for dyeing. Orcin is colorless when pure, but becomes reddish-brown by ex- posure to the air. Its crystals, with one molecule of water, melt at 58 C., and becoming anhydrous the mass distils at about 290 C. It is soluble in boiling water, alcohol, ether, or boiling benzene. It is capable of decomposing alkali carbonates with effervescence. Hypochlorites give, with even a trace of orcin, a transient, intense purple red color. Ammonia, with exposure to air, quickly converts orcin into orcein, with its deep purple-red color. Orcein dissolves sparingly in water, to which it gives its fed color, dissolves freely in alcohol, and freely in aqueous alka- lies with violet-red tint. Acids precipitate it, in part, from the alkaline solution, and water precipitates it from the alcoholic solution. It is bleached by ammonium sulphide ; also by zinc added to an ammoniacal solution previously acidulated. Reactions of Coloring Materials, according to Fol. 1 Slues. Solution of citric acid or dilute hydrochloric acid is added. (a) Color changes to red or orange. Logwood-Hue. (b) Color does not change. Solution of calcium chloride is added to a fresh portion of the dye-stuff. (a) Color remains unchanged. Prussian Hue. (o) Color changes. Solution of caustic soda is added to a fresh portion. (a) The substance is decolorized. Aniline-Hue. (b) It remains unchanged. Indigo-Hue. Yellows. A portion is tested for ferric oxide by means of potassium ferrocyanide ; another part is tested for picric acid by means of 1 F. FOL, 1874 : Ding. pol. Jour., 212, 520. FOL'S METHOD. 193 potassium cyanide solution. The production of a blood-red color indicates picric acid. If the colors do not appear, another portion is treated with a boiling solution of 1 part of soap in 200 parts of water. (a) The color changes to brown, but becomes yellow again with an acid. Turmeric. (b) The color becomes very dark. Fustic. (, p*9 JS &5 8 e) II to f-l " c2 D *rt s o ^ Qg s 11 1" I 11 1 1 1 p p , ti d M ii . - 3 '53 c 8"S C c ^ i c 8 E II 1 1 fl ll ll 11 | OD 1 l! ll 1 ^2 s o g p o> O s 5 g 1 i 1 1 J33 a a r2T) Srg | 1 1 1 2| si 1 M 1 K 2 1 i P P .2 P ll o 1 1 | i - d lorless. .. s i p J 15 o V JQ RM fc o 1 1 -j T - .. Is 1. : Z 1 i g 2 a 2 2 I J d ^ "o & ^i- i 1 IQ i 5 B e oT " S if B-? c '? 1 I I 1 !l "3 H 1 g c "S | a a 1 'S 1 '5 G I 5 c <5 5 3 e 1 1 a REACTIONS OF DYES. 197 d s 2 s d d a ^ "^ ,O ^ cd 5 ,0 [2 ^ ig 1> ^ .Q ^ 3 3 ^ri | 5 I 'ft S.2" _= cs'ft a ^ "1 -g 3 g - | C 1 g 'o g is ^ 2 oS fc ft ft * ft * a S 1 2 d S d 2 w X ^ * S 5 si j ,3 j 3 m 3 3 j 3 Q . . 3 o'ft S 'S, M .' +- 1 * *-* rO -r-t ^^ P i O * P5 o o f " o * * S fc ft ft ft * J S ^ ^ j ^ "s a i 5^ 3 g 1 3 3 g 1 g S 5 5 o ft 3 n 3 5 2 *j "o ^ ffl a; - S g 3 ^ O | 3 * ft ^ K g L S.3 O -^ .= - !I 4 it _>. o d ^ K fcC _j OJ K C Alizarin. p 31 o ^s '5.S lit |!l Vesuvin-Bro a H i Aniline- Vfo soluble. Aniline-Viol insoluble Aniline-Yell Chrysamm Acid. Corallin. 198 ELEMENTARY ANAL YSIS. CONCHAIRAMINE, CONCUSCONINE. See CINCHONA ALKALOIDS, p. 92. COTTON-SEED OIL. See FATS AND OILS. CREAM OF TARTAR. See TARTARIC Acm CUPREINE. See pp. 92 and 153. CRYPTOPINE. See OPIUM ALKALOIDS. DYES. See COLORING MATERIALS, p. 181. ; . '. * ECGONINE. See p. 172. ELEMENTARY ANALYSIS OF CARBON COMPOUNDS. A. qualitative analysis for the organic elements, C, H, and N, is only made for the purpose of determining whether a carbon compound be present or not, or whether a given or- ganic compound be nitrogenous or not. In the case of bodies not rapidly volatile, (1) ignition in the open air, either on platinum foil or in a glass tube open at both ends, will show carbonization in case a carbon compound be present. The fact of carbonization is shown first by the appearance of a black resi- due, and then by its gradually burning away. In the case of volatile bodies, or when for any reason the result of simply ignit- ing the body by itself proves uncertain, a resort is had to (2) igni- tion with copper oxide in a small combustion-tube, with tests of the gas evolved. The dry substance is mixed with an excess of copper oxide (previously ignited and cooled), the mixture intro- duced into a small. tube of hard glass, the tube being closed at one end and fitted at the other with a tubulated cork carrying a small glass tube bent at right angles. On applying heat, very gradually, to the combustion- tube, the resulting gas is passed into lime solution or baryta solution. If a precipitate be formed this is to be gathered in sufficient abundance, and its solubility in acetic acid with effervescence is tried, for the identification of carbon dioxide. Meantime it is observed whether there be con- densation of liquid in the bent tube or not, and droplets so ob- tained may be tested, with anhydrous cupric sulphate, for water, as evidence of hydrogen. But this evidence is dependent upon the absence of moisture or hydrates in the contents of the com- bustion-tube. Unless the result of the simple test just men- tioned be clearly conclusive, it is better to use the safeguards ELEMENTARY ANALYSIS. 199 against moisture directed for Quantitative estimation of carbon and hydrogen. That is, the substance and the copper oxide are properly dried and secured from the moisture of the air, and the air in the tilled combustion tube is replaced by dried air, before the combustion. Then the combustion is conducted very slowly, and the small conducting tube is kept cold. To be certain that carbon dioxide obtained by ignition does not come from carbon- ates that is, from non-alkali carbonates or alkali bicarbonates the material is first to be tested for carbonates. If these are present, enough of hydrochloric or sulphuric dilute acid is add- ed, and the material dried again. If it be found that a carbon compound be present, to tind whether it be a nitrogenous compound or not, it is sufficient, in the greater number of cases, (3) to heat the dry substance, well mixed with dry soda-lime, when the nitrogen is given off in the form of ammonia. The heating must be to redness, and thorough drying of the material, as well as previous ignition of the soda- lime, render the operation much more convenient. An ordinary test-tube may be used for this combustion ; but a section of com- bustion-tubing, of hard glass, with one end closed, serves better. The tube may be wrapped in a strip of copper gauze near the open end, and held by the forceps, while the heat of the flame is very gradually applied. The test for ammonia is made by moist- ened red litmus-paper, also by the odor, and the color given a drop of dilute solution of copper sulphate held on a loop of pla- tinum wire. Bodies rich in nitrogen give the odor of singed hair when merely burned in the air. Heating with fixed alka- lies does not cause the production of ammonia from the nitrogen of all organic bodies. Some bodies so treated yield vaporous alkaloidal compounds, mostly showing the alkaline reaction to litmus, but not exhibiting other characteristics of ammonia. Other bodies, as many of the nitro-compounds, when treated by combustion with fixed alkali, give no indication of the presence of nitrogen. For these it is necessary, and for all it is sufficient, to (4) heat the substance with a fragment of metallic potassium for some time (SPICA, 1880), and then test the mass for cyanides. The fused mass is digested with hot water and a ferrous salt, acidulated, and a drop or two of ferric salt solution added. The blue color of ferric ferrocyanide gives evidence of nitrogen in the material taken. Also the test may be made for production of sulphocyanate by digesting the mass (after fusing with the potassium) with ammonium sulphide, and then acidu- lating. A qualitative examination for sulphur y pliosphorus, sele- 200 ELEMENT A RY A NA L YSIS. nium, and arsenic may be made by applying a strong oxidizing agent, and then testing for sulphuric, phosphoric, selenic, and arsenic acids. The material (free from the acids last named) is either digested with strong nitric acid (sp. gr. 1.42) or smelted with potassium nitrate, afterward treated with water, and the fil- trate tested for the acids. For arsenic the material may be treated, as in the examination of animal tissues for arsenic, by drying, digesting with concentrated sulphuric acid and repeated small additions of nitric acid until the carbon compounds are oxidized, and the nitric acid then wholly expelled, afterward neu- tralizing with magnesia, and subjecting the filtrate to Marsh's test for the arsenical mirror. Arsenic will sometimes be found by igniting with sodium acetate, when cacodyl compounds are revealed by their odor. Phosphorus may usually be found by heating the carbonized material with powdered magnesium, inti- mately mixed, in the bulb of a reduction-tube, after which phos- phorescence appears in the dark. For chlorine, bromine, and iodine, as elements in an organic compound, it is necessary to effect such a decomposition as will- bring the chlorine^ etc., into union as chlorides, etc., or into the elementary form. Thus chloral, chloroform, and other similar compounds do not react with silver nitrate to form silver chlo- ride, etc. The necessary liberation of the haloid elements is ob- tained in some cases by digesting with strong potassium hydrate solution, in other cases by igniting in mixture with an excess of lime (each of known purity), after which the aqueous filtrate may be acidified with dilute nitric acid, and treated with silver nitrate solution for precipitates. See further upon the quantitative de- termination of the halogens. To remove organic substances, in preparation for a search for inorganic bodies in general, methods of ignition, use of oxidizing agents, application of solvents, and dialysis are described in the author's " Qualitative Chemical Analysis," third edition, para- graphs 773-778. Finally, in qualitative analysis for the elements in a portion of organic matter, instead of the direct examination for these elements, above described, the analyst will most often determine at once what organic compounds known in chemistry he has in hand, recognizing their likeness by their sensible qualities, fixing their identity by well-tried qualitative reactions, resorting to ap- proved means for their separation, and proving their purity by authorized tests for this purpose. A constant boiling point and prescribed melting and congealing points are sought. The qualitative determination of a known organic compound carries ELEMENTARY ANALYSIS. 201 with it the evidence of the constituent elements of the compound. Just as qualitative tests for ortho-phosphoric acid, and for its purity, prove the presence of phosphorus and hydrogen and oxy- gen in combination as H 3 PO 4 ; so qualitative tests for benzoic acid, and for its purity, suffice to show that only carbon and hy- drogen and oxygen are present, and that these elements are united as CgHgCC^H. The means of separating organic compounds, and purifying them, have much in common with like means for inorganic bodies. Solvents are applied, precipitations are made, crystallization is instituted, fractional distillation is performed, chemical reactions are applied ; and these and other means, as given throughout this work, are persevered in until, in all quali- ties, constants are reached. But when in the course of research a new organic compound is obtained, and separated in purity, as shown by constant properties, it becomes necessary to find what elements it contains and in what proportion they stand. Quali- tatively, in most cases it is evident from the origin and proper- ties of the new body what elements it contains ; so that the inves- tigator may proceed at once to establish quantitatively, by the methods of organic combustion next to be described, in what proportions the elements are united, and then what molecular weight it has and under what chemical formula it is to find a place in science. Further upon the scope of qualitative and quantitative organic analysis, often termed " proximate organic analysis," and to what extent it depends upon elementary or " ultimate " organic analysis, see the article upon ORGANIC ANALY- SIS in this work. ELEMENTARY ORGANIC ANALYSIS, in the Quantitative Deter- mination of the Elements of an Organic Compound often termed " Ultimate Organic Analysis" rests upon the principles already outlined for the Qualitative Determination of the Organic Ele- ments. For the carbon and hydrogen a complete combustion is instituted in such a way that the combustion-products, carbon dioxide and water, are obtained as measures of these two funda- mental elements. And this simple application of the chemistry of combustion has been the means of obtaining the quantitative composition of organic bodies, from the first establishment of chemical science to the present time. 1 For nitrogen, either an 1 LAVOISIER, 1781-1784: burning of the substance with a measured volume of oxygen, and measurement of the volume of carbon dioxide produced, for cal- culation of weight : Mem. A cad. Sci., 1784-87. BERTHOLLET, 1810: Mem.de I'lnstitut National, u, 121. SAUSSURE, 1807-1814: Ann. Chim. Phys.. 62, 225; 78, 57; 89, 273. GrAY-LussAc and THEXARU, 1810-1810: use of chlorate 202 ELEMENTAR Y ANAL YSIS. ignition with fixed alkali is made to yield ammonia for determi- nation, or, more often, combustion with its products carried over heated metallic copper is made to furnish free nitrogen for measurement. The oxygen is obtained by difference. Methods for direct estimation of the oxygen have been proposed from time to time, as briefly indicated in succeeding pages, but none of them has come into actual use. The supply of oxygen for combustion is obtained as follows : (1) From copper oxide. This is either granular or in powder, coarse or fine. It is made by heating copper turnings or copper scale with nitric acid, finally to ignition, or by igniting copper nitrate prepared for the purpose. "The granular form is obtained by incipient fusion. Both granulated and coarsely powdered copper oxide is to be of uniform size, by sifting, free from dusty oxide. For most uses in the combustion- tubes, the granular form moderately coarse, or that from the turnings, or the coarse powder is to be chosen, in .preference to fine powder. That is, the column is to be sufficiently permeable by gases, so that it will not be necessary to have a channel over the oxide, in the tube. To intermix with the substance under analysis finely pul- verized oxide is sometimes employed, or obtained by trituration of the granular form during the intermixing. Oxide of copper, when heated, must evolve no nitrous fumes nor carbon dioxide. It is hygroscopic to a considerable extent, and in combustion for carbon and hydrogen it must be absolutely dry. For nitrogen determinations it is desirable to have it dry. It may be ignited, in a hessian crucible, short of incipient fusion, and \vhen still warm put up in a flask with a neck a very little wider than the combustion-tube, and closed by a perforated stopper bearing a dry ing- tube of chloride of calcium. Also, it may, with advan- tage, be dried by ignition in the combustion-tube, in a current of dried air. This may be done when the oxide is to be after- ward removed from the tube to the flask in preparing the sub- stance for combustion, and it may with still greater advantage be done when the substance is burned in a boat. In use copper oxide is reduced to cuprous oxide or to metallic copper. With as source of oxygen and introduction of copper oxide, also the determination of nitrogen: Ann. Chim. Phys., 74, 47; Schweiger's Journal, 16, 16. DOBEREI- NER, 1816: Schweiger's Journal, 18. 379. BERZELIUS, from 1814: the use of horizontal combustion-tubes of glass. LIEBIG, 1831 : combustion with copper oxide, in detail nearly the same as " Liebig's method" sometimes employed at present: Ann. Phys. Ckem. Pogg., 21, 1 (application to cinchona alkaloids). BRUNNER, 1838: oxygen gas supplied for combustion: Ann. Phys. Cfiem. Pogg., 44, 138. BUNSEN: intermixture with copper oxide in the combustion- tube. ELEMENTA RY ANAL YSIS. 203 the supply of oxygen gas at the close of combustion, the reduced copper is restored to oxide. Otherwise it may be restored by adding nitric acid, heating, and igniting. (2) From.' lead chro- mate. This must contain nothing soluble in water, and yield no carbon dioxide when heated. It fuses at a red heat. It is pre- pared by melting in a hessian crucible and pouring out upon a stone slab, when it is pulverized moderately tine, sieved, and bottled for use. Or the melted chromate may be poured into water in a copper vessel, and the granulated mass collected, dried, and pulverized. It is not hygroscopic. In melting it adheres to the combustion-tube. In use it is reduced to the green chromic oxide with lead oxide. To use it a second time it is roasted, fused, and pulverized. After the second time it requires oxidation, by digesting the powder with nitric acid, drying, fusing again, and powdering. Lead chromate is em- ployed instead of copper oxide when sulphur, or selenium or tellurium, is present ; also, when very difficultly oxidizable sub- stances are in hand. Its greater efficiency as an oxidizing agent lies chiefly in its being fusible during the combustion. MAYER (1855) introduced into the powdered lead chromate one- tenth its weight of potassium dichromate previously fused and pul- verized. This mixture serves to expel from alkalies or alkaline earths, if these be present, the carbon dioxide they may have absorbed from the products of combustion. (3) A stream of oxygen gas is employed. This is supplied most evenly and satis- factorily from a pair of gas-holders, the one tilled with oxygen, and the other with atmospheric air, the stream from each being purified by passing through at least two U -tubes, one filled with pumice-stone and sulphuric acid, to dry the gas, and the other tilled with fragments of potassium hydrate to remove carbon dioxide. Also, without a gas-holder, a stream of oxy- gen is obtained by generating this element, in the further end of the combustion-tube itself, from lead dioxide, heated in an air-bath to. 180-200 C., or by heating mercuric oxide or po- tassium chlorate by the flame. Oxygen is sometimes generated in the combustion- tube from chlorate of potassium placed in a pla tinum boat and subjected to heat. In the preparation of oxygen for the gas-holder, chlorate of potassium, well mixed by tritura- tion with one-thousandth of its weight of ferric oxide (FRESE- NIUS), is heated over the flame in a plain glass retort not over , half filled. The heat is applied very gradually, and as soon as the salt begins to fuse the retort is gently shaken. When the air is expelled the connection is made with the gas-holder. If the proportion of ferric oxide be exactly adhered to, the evolu- 204 ELEMENT A RY A NA L YSIS. tion of gas will not be impetuous. 100 grams of the chlorate will yield about 27 liters of oxygen. Oxygen gas is tested for chlorine by passing it through silyer nitrate solution, and for carbon dioxide by passing through lime solution. A splinter of wood which has been kindled and blown out should burst into a flame when introduced into a stream of oxygen gas. The soda-lime used as the fixed alkali, for the conversion of organic nitrogen into ammonia in the combustion -tube, 1 is a mixture of two parts of calcium hydrate with one part of sodium hydrate. It is usually made by the evaporation of a solution of sodium hydrate with the proportional quantity of slaked lime. S. W. JOHNSON (1872 a ) recommends, as more convenient and even better, a mixture of equal parts of crystallized sodium car bonate and slaked lime, prepared by evaporating the mixture. 8 Soda-lime is obtained in granular form, more convenient for the greater part of its uses than the powdered form. It should not evolve any trace of ammonia when heated with sugar; it should not be more than slightly moist ; and (unless prepared upon Johnson's direction) should not effervesce very much upon the addition of acids. It is made ready for use by igniting in a hessian crucible at a gentle heat, and while warm it is put up in a well-corked bottle, or a bottle with a tubulated stopper carrying a drying tube containing both calcium chloride and a little gran- ulated soda-lime. Metallic copper is used, while heated, to reduce oxides of nitrogen in the combustion-tube, this being necessary, first, to prevent error in estimating carbon by the absorption of carbon dioxide ; second, to avoid loss of nitrogen in estimating this ele- ment by its volume when free. Coils of copper gauze or foil, or spirals of copper wire, are heated to redness in the air long enough to oxidize the surface, and then heated in a stream of hydrogen to reduce the oxide formed. For the reduction the coils are introduced into a combustion-tube having a tubulated stopper at each end, and a current of hydrogen passed throng] i 1 VARRENTRAPP and WILL, 1841: Ann. Chem. Phar., 39, 257. 2 Am. Chemist, 3, 161; 1879: Am. Chem. Jour., i, 77. 3 " Equal weights of sal-soda, in clean (washed) large crystals, and of good white and promptly-slaking quicklime, are separately so far pulverized as to pass holes of T V inch, then well mixed together, placed in an iron pot, which should not be more than half filled, and gently heated, at first without stirring. The lime soon begins to combine with the crystal water of the sodium carbonate, the whole mass heats strongly, swells up, and in a short time yields a fine pow- der, which may be stirred to effect intimate mixture and to dry off the excess of water, so far that the mass is not perceptibly moist,' and yet short of the point at which it rises in dust on handling. When cold it is secured in well- closed bottles or fruit-jars, and is ready for use" (>t'/iere last above cited). ELEMENTARY ANALYSIS. 205 until the air is expelled, when heat is applied as the stream of hydrogen continues. Coarsely franulated copper oxide, reduced y ignition in a current of hydro- gen, is employed to some extent instead of the spiral coils, and is more efficient than they. All copper reduced by ignition in a stream of hydrogen is liable to contain traces of occluded hydro- gen, from which error may arise unless precaution be taken. 1 At ordinary temperature it quickly absorbs moisture from the air. Copper gauze and wire are also used in the combustion -tube in methods of combustion of non-nitrogenous bodies, requir- ing only to be cleaned by a mo- mentary ignition in the clear flame before use. Solution of Potassium Hy- drate. To absorb carbon dioxide in potash bulbs, good potassium hydrate nearly free from carbo- nate is dissolved in an equal weight of water. Some chemists use a solution in 2 parts of water ; others a solution in | part of water. The solution dropped into diluted mineral acid should not effervesce. It should be strictly free from nitrite. It is sometimes used a second time. Solid hydrate of potassium is also employed for absorption in elementary organic analysis, taken either in stick or in lump, the drier the better. Chloride of Calcium. For absorption of the water resulting from combustion, dried calcium chloride strictly free from alka- 1 G. S. JOHNSON, 1876: Jour. Chem. Soc., 29, 178. 206 ELEMENTARY ANALYSIS. line reaction is employed. In preparation the solution is stirred while evaporating, to granulate, and the residue dried at about 200 C. It consists of CaCl 2 .2H 2 O. The granulated form is much preferable. It may be tested, in concentrated solution, with litmus-papers. It may be prepared from crude fused cal- cium chloride by dissolving in lime solution, filtering, neutraliz- ing with hydrochloric acid, evaporating to dryness, and heating ms above directed. But to be well assured that the calcium chlo- ride is free from uncombined bases, the operator should take the precaution to pass dried carbon dioxide through the filled chlo- ride of calcium tube for an hour or two, and then a current of dried air to restore the normal weight of the tube. For drying gases the crude, fused calcium chloride, in broken masses, is all that is required. It usually has an alkaline reaction. Combustion-tubing is to be of hard potash-glass, mostly of 12 to 14 millimeters ( T \ to inch) inner diameter, and about 2 millimeters (not quite J inch) thickness of glass. It is best obtained in lengths sufficient for two tubes that is, in pieces mostly 5J to 6J feet long. For many purposes the combustion- tube is drawn out at one end, and preferably in bayonet form, as in Fig. 9. A section of tubing long enough for two combustion- 6 Fig. 9 c <* tubes is readily so drawn and bent that when severed in the cen- tre the two finished tubes are obtained. The edires are to be rounded in the flame. A combustion-tube is cleaned with a piece of muslin or paper attached to a stiff wire, and is dried by heating over a flame or on a water-oven, while from time to time the air is drawn out through a small tube carried in to the closed end, when it is well stoppered. Combustion -tubing of glass not sufficiently infusible may be used by wrapping it with copper gauze. Iron tubes are some- times used, with special precautions, especially for nitrogen de- terminations by ignition with the soda-lime (CLOEZ, 1863 ; JOHN- SON, 1879). A hard-glass tube may be used repeatedly for combustion in a stream of oxygen gas, and sometimes more than once for combustion with admixture of the substance with oxide of copper, not more than once for combustion with chromate of lead. Chloride of Calcium Tubes, for the absorption of the water of combustion and for drying gases, are used of various patterns. ELEMENTARY ANALYSIS. 207 including the one-bulb and two-bulb straight tube, and the U-tube with and without a bulb : Fig. 10, and in position in Figs. 8 and 16. The tubulated stoppers should be of rubber, or cork waxed over. An empty bulb in the horizontal part of the chloride of calcium tube has the advantage that it serves as a cup for a por- tion of the water which condenses in it, and the chloride of calcium the longer retains its power of absorption. A tuft of cotton-wool is drawn into the tube, so as to rest firmly against and within the narrow part of the tube through which the current enters, when the fragments of calcium chloride are filled in, and at the other end a cover of cotton-wool or muslin is placed. Concentrated Sul- phuric Acid has been variously used, instead of calcium chloride, to absorb the water. 1 Potash bulbs are of the two principal patterns, GEISLER'S, Fig. 11, which are to be preferred, and LIEBIG'S, Fig. 12, which have long been used. When in use the larger bulb is placed next the combustion-tube. In being filled, the end which is nearest the combustion the one into which the stream of gas is Fig. 11 to enter is inserted into the solution of potassa, and a sufficient amount of the liquid is drawn into the apparatus. The proper quantities of potash solution are shown in the figures. Instead of a bulb apparatus for potash solution a large bulbed U-tube, filled with sodarlime, is sometimes used as an absorbent of the carbon dioxide of combustion. A potash tube, either straight or 'DIBBITS, 1876: Zeitsch. anal. Chem., 15, 122; MORLEY, 1885: Am. Jour. Set'.. [3]. 30, 140; Chem. Neivs, 54, 33. 208 ELEMENTARY ANALYSIS. ll-form, filled with fragments of dry potassium hydrate or with granulated soda-lime, is used beyond the potash bulbs, and weighed with it. It guards against loss of water-vapor and of traces of carbon dioxide. The Combustion- Furnace of ERLENMEYER is shown in Fig. 8, p. 205. It requires a good supply of gas. The combustion- furnace of GLASER, preferable for some combustions, is shown in Fig. 16. In the use of a gas combustion-furnace the supply of air must be regulated with that of gas to each burner. The furnace should be placed where it will be secure against currents of air or the access of acidulous or ammoniacal gases. THE CONDITIONS OF SUCCESS in organic elementary analysis are attained by a watchful attention to details, with a faithful study of the sources of error, throughout the operation and in the preparation for it. The sources of error are so many that even an experienced operator, when commencing work with newly collect- ed appliances, is quite liable to failure. When the work is well in hand, and operations upon material of known composition are made to succSed each other with almost invariable success, an important estimation may be undertaken with confidence in the result, but this is to be obtained as the mean of several nearly coinciding determinations. ESTIMATION OF CARBON AND HYDROGEN IN BODIES NOT CON- TAINING NITROGEN. Oxygen supplied by Copper Oxide. Analy- sis of Solids. The substance to be analyzed, obtained of exactly constant composition, in respect to hydration and freedom from all foreign matters, and (if pulverizable) in very fine powder, is introduced into a small weighing-tube a light cylindrical con- tainer, with a caoutchouc or fine cork stopper, and of 3 to 6 c.c. capacity. For each elementary estimation from 0.3 to 0.4 gram is usually taken, and estimations may require repetition ; therefore it is better to take from 2 to 4 grams of the sample at once in the weighing- tube, so that all the desired estimations can be made upon material of constant composition, without danger of loss or gain of moisture or other constituents. When it is desired closely to regulate the quantity of substance for each combus- tion, it is well to employ in addition a smaller weighing-tube to receive enough for one combustion, which is transferred from the larger weighing-tube. The management of liquids, soft solids, arid very volatile matters is given hereafter (p. 213). The charging of the combustion- tube, under whatever order of arrangements, is to be so effected that the entire contents of the tube including the substance under analysis, the material ESTIMA TION OF CARBON AND HYDROGEN. 209 supplying oxygen, oxygen gas, and atmospheric air shall be strictly free from moisture before the combustion begins. To remove moisture and exclude it from the materials and the air entering into the combustion-tube, different orders of operation are adopted in different laboratories and directed by different authorities. When the substance is not burned in a boat of platinum or porcelain, and when the oxygen is supplied by copper oxide, the work may be conducted as follows : The filled potash bulbs, dried with filter-paper at the ends and wiped clean, with the attached potash tube (if this be employed), are weighed, and both openings are afterward closed with sections of clean rubber tubing stopped with a bit of glass rod. The chloride of calcium tube is weighed, and its ends afterward closed. The weighing-tube, narrow and of considerable length, containing the substance for analysis, is weighed without opening it. There is provided granulated oxide of copper, which has been taken after ignition, and while warm, into a filling-flask. 1 as described on p. 202. The dry combustion- tube, with its drawn-out end sealed, is rinsed with some oxide of copper. About four inches (10 centimeters) of the body of the combustion-tube is filled with the oxide of copper, taken from the flask by the mouth of the tube. The substance is added, upon the layer of copper oxide, from the weighing-tube, which is in- troduced into the combustion-tube, avoiding the adhering of the substance to the inner surface. The weighing-tube is closed and put aside to weigh again. Another layer of oxide of cop- per equal to the first is taken into the combustion-tube, add- ing at first in such a way as to rinse the latter. With a stiff iron wire as long as the combustion-tube, bent in a single cork- screw turn at one end and in a ring at the other (Fig. 8), the substance is well mixed with the oxide of copper, leaving undis- turbed about 4 centimeters (l inches) of the layer of oxide next to the bent end. Oxide of copper is added to fill to within about 6 centimeters (2J inches) of the mouth. A porous plug of as- bestos is added, leaving a good free space, to be kept clear of condensed water, between the asbestos and the tubulated caout- chouc stopper. If a cork stopper be used less space is required. Another method of charging the tube, when copper oxide is the sole source of oxygen for combustion, provides for mixing 1 The copper oxide may be dried by ignition in the tube with advantage in this method as in others. The. tube "is filled with the oxide, then the open drawn-out end is connected with a set of drying-tubes, and dried air is either sent by a gasometer or drawn by an aspirator through the drying-tubes and the oxide of copper, while the latter is ignited. 210 ELEMENTARY ANALYSIS. the substance with some of the oxide of copper in a mortar of glass or unglazed porcelain. The warmed mortar is placed 'on a sheet of glazed paper on the table, and the oxide of copper is taken warm. Both the tube and the mortar are rinsed with some of the oxide of copper, and the rinsings put aside to be ignited again. After a layer of about an inch (2 centimeters) of the oxide of copper next to the bayonet-end of the tube, a mix- ture of the substance with oxide of copper is made by gentle tri- turation in the mortar, and added in such quantity with the mortar rinsings as will fill the tube to or a little beyond the mid- dle of its body. The remainder of the tube is filled with the copper oxide to within about 2J- inches (or 6 centimeters) of the mouth, covering with a porous plug of recently ignited asbestos. When the contents of the tube are in fine powder a channel for the easy passage of gases is made by tapping the tube upon the table as it lies in horizontal position. With granulated cop- per oxide, or that in coarse powder, a channel is usually to be avoided. The removal of atmospheric moisture from the filled com- bustion-tube, when a gaseous supply of oxygen is not used, may be accomplished by attaching a drying-tube of chloride of calcium, and repeatedly pumping out the air, which is each time permit- ted to flow back through the drying-tube. A small exhausting- syringe may be used, or a filter-pump acting through a flask provided for the admission of air at will. But it is a more satis- factory way to pass a current of dried air, drawn by an aspirator or sent by a gasometer, through the tube from the drawn-out end, as directed further on to be done for another purpose after the combustion (p. 212). When the contents are dried the com- bustion-tube is kept closed by a caoutchouc stopper until con- nected with the weighed chloride of calcium tube and potash apparatus for the combustion. Chr ornate of lead (p. 203) is used instead of oxide of copper for substances difficultly oxidizable, as well as when sulphur is present. In the charging of the tul)e it is used in the same man- ner as oxide of copper. Having a higher oxidizing power than copper oxide, a smaller quantity is required, and a narrower tube may be used. The contents of the tube should be dried the same as when oxide of copper is used. Bichromate of Potassium, with Oxide of Copper, may be used as follows (GINTL, 1868): The combustion-tube is charged, first, with about 2^ inches (6 centimeters) length of granulated copper oxide ; then with about 1J inches (3 centimeters) length of acid chromate of potassium which has been fused, pulverized, and ESTIMA TfON OF CARBON AND HYDROGEN. 211 kept dry ; then the substance added from the weighing-tube, and again oxide of copper to make about 1^ inches (3 centimeters). with the mixing wire (p. 205) the substance is well mixed, leaving undisturbed about half of the layer of copper oxide next the bayonet-end. The tube is filled with copper oxide ; an as- bestos support is placed, providing an open space next the tubu- lated stopper ; and the contents of the tube are deprived of moisture, as before directed. In makiny the combustion with oxide of copper, the com- bustion-tube is placed in the furnace with the end next the chlo- ride of calcium tube projecting as far as the asbestos plug. A disc of copper foil may be employed as a shield over the tube to protect the stoppered end from too great heat. The tightness of the apparatus can be assured by expelling a little air, by heat- ing the bulb of the potash apparatus nearest the combustion-tube until a few bubbles of air have escaped, when the liquid rises on the side heated and should then remain stationary. If the rubber connecting tubes are not snug they are bound with wire. The oxide of copper next the chloride of calcium tube is heated first, very gradually, to dull redness, and the heat is steadily carried toward the substance, not rapidly enough to cause a tumultuous escape of expanded air through the potash bulbs. At the end near the mouth the combustion-tube is maintained uniformly at a temperature high enough to prevent the condensation of water- vapor within, but not high enough to endanger melting the tubulated stopper if of caoutchouc, or charring it if of cork. The column of copper oxide, back to where the combustible substance begins to be intermixed, is held at dull red heat, not high enough to endanger blowing-out of the glass, while now the heat is carried very gradually back through the substance itself so gradually that not more than one or two bubbles a second will pass the liquid in the potash bulbs. Certainly the bubbling should not at any time be too rapid to be counted. There should not be empyreumatic odor in the escaping air. When the air has been nearly all expelled, and the gas which passes out of the chloride of calcium tube consists mainly of carbon dioxide, the bubbles will pass through the last potash bulb only at conside- rable intervals, and these intervals will be longer if that portion of unmixed oxide of copper back of the substance be heated, as it may be in part and with caution, before the substance begins to burn. At the end of the operation all the contents of the tube are held at full heat. As the current of carbon dioxide ceases the liquid in the potash bulb next to the combustion-tube rises. Slight suction may now be applied to the potash tube. 212 ELEMENTARY ANALYSIS. At this time, or in anticipation of the time when the combustion with the copper oxide is completed, the heat is turned off under the rear end of the coinbustion-tube so that the drawn-out extre- mity is cooled, and this is then connected by a rubber tube with a set of tubes for thoroughly depriving air or oxygen of moisture and carbon dioxide. Such a set of tubes is described, together with the means of supplying oxygen and air, in the directions for combustion in a current of oxygen gas, following. The pot- ash tube is connected with an aspirator, either the bell jar form shown in Fig. 16, or a bottle aspirator, serving not only as a pump but as means of regulating the flow of gases supplied, and of preventing recession of the current. To remove now the carbon dioxide and water-vapor in the combustion-tube, and at the same time insure the absolute com- pletion of the combustion, if oxygen gas has been provided, it is better to pass purified oxygen gas from the connection at the bayonet-end (Fig. 13) through the combustion-tube while it is U JJJJ JJ JJ JJ JJ _U JJ JJ JJ JJ JJ JJ JJ U U Fig. 13 heated. The connection is opened by breaking the point of the combustion-tube, in the rubber-tube, with a pair of pliers, and a sufficient stream of oxygen is passed. Now, as oxygen has a higher specific gravity than air, the former is to be removed from the absorption-tubes to be weighed, by washing it out with a stream of purified air. This is done by changing the connection from the oxygen gasometer to an air gasometer (the position of which is shown in Fig. 13), taking air through the same tubes for depriving it of carbon dioxide and moisture. Or, without a gasometer for air, the previous connection with the oxygen sup- ply may be opened for the admission of air, purified as just stated, and drawn througli by the aspirator, long enough to' re- move the oxygen. As soon as the stream of air is applied the heat may be diminished, turning it down very gradually to avoid the breaking of the combustion-tube. Without oxygen gas, air ESTIMA TION OF CARBON AND HYDROGEN. 213 dried and purified as above directed may be drawn through the combustion-tube while it is maintained at full heat, until the carbon dioxide is removed from the apparatus. The combustion of a substance mixed with copper oxide and with a stream of oxygen throughout the operation, as sometimes done, can be readily understood from the directions foregoing, together with those * given in the following pages upon Combustion in a Pla- tinum Boat with gaseous oxygen. Again, some operators, with the benefit of experience, merely break the point of the com- bustion-tube in the open air, and draw through, by the aspirator or by the mouth, sufficient air to displace the gaseous content of the apparatus, as indicated by the bubbles no longer diminishing in size as they pass the potash bulbs. The chloride of calcium tubes, and the potash bulbs with the potash tube, are at once closed with the caoutchouc caps, and are weighed without these additions. With lead chromate the combustion is conducted so that the chromate between the substance and the mouth of the tube is not fused, but remains porous. The lead chromate intermixed with the substance is not fused at first, nor until the substance has all been heated ; but it should be wholly fused at last, because it is a much more powerful oxidizing agent in the liquefied state. The errors to be guarded against in combustion with oxide of copper or chromate of lead are those of too high figures for hydrogen and too low figures for carbon. With dry potash in the end tube, the use of an aspirator, and a stream of dry air to recover the carbon dioxide left in the apparatus at the close of the combustion, the loss of carbon may be avoided. To prevent an excess of hydrogen requires vigilance, its accomplishment lying mainly in the absolute removal of moisture before combus- tion. It lias been stated ' that without the potash tube the carbon averages about 0.1 % too low, while with the potash tube it averages near 0.05^ too high ; and that [without the substitution of dried air in the filled combustion-tube] the hydrogen averages 0. 1 to 0.2$ too high. Liquids are weighed and introduced into the combustion-tube in glass bulbs. For volatile liquids these may be made by draw- ing out wide tubing, Fig. 14, the drawn-out portion being about 5 millimeters (^- inch) in external diameter, and in the wider portion about 3 centimeters (1J inches) long. For either volatile or non- volatile liquids bulbs of the shape shown in Fig. 15 1 KEKULE'S " Organische Chemie." 1867, i. 22. 2 14 ELEMENTAR Y ANAL YSIS. may be employed. Bulbs are filled by passing through the flame to heat the air they contain, and then immersing the open end in the liquid, which presently rises to fill part of the tube. If the liquid be volatile, it may now be made to boil in the tube, when, the open end being inserted in the liquid, an additional quantity is obtained. If an open bulb be placed with its mouth under the surface of a liquid, and the whole put under an air-pump, on drawing out the air the liquid rises afterward in its place. Non- vola- tile and slightly volatile liquids are weighed and introduced into the com- bustion-tube in open bulbs ; freely Jiff 14 v l a til e liquids are weighed in sealed bulbs. In any case the weight of the empty bulb . is taken before filling ; and the capillary neck of the bulb is drained as fully as possible after filling. To seal the mouth it is held a moment in the flame, and when cool it is ready to be weighed. The combustion of non-volatile liquids, and soft solids is much better done with a stream of oxygen gas, in a platinum boat. The products of destructive distillation are burned almost as fast as formed, the substance itself being heated very gradually. On the other hand, when freely volatile bodies are burned in oxygen gas, care is required, owing to some liabi- lity of explosion in the combustion-tube. The use of oxygen gas to complete the combustion of the carbonaceous residues of volatile substances is, however, always desirable. And WARREN 1 has presented a method of burning volatile bodies with oxygen gas, by means of a combustion-tube packed with asbestos, the heat being applied and the combustion effected only in the an- terior end of the tube, while the substance is vaporized in the posterior end. A long combustion- tube is used, and the column of porous asbestos packing acts like the gauze of Davy's safety- lamp. In filling the combustion-tube, when liquid or volatile bodies are to be burned with copper oxide, the coarsely granular oxide is taken, a layer of about two inches of the same is placed at the posterior end, the substance contained in two bulbs is in- troduced with some copper oxide between them, while the com- bustion-tube is upright, and the tube is filled up with copper oxide. If the bulbs have been sealed, a file-mark is made upon the neck, which is broken as the bulbs are dropped into the tube. Very volatile substances are sometimes introduced in small por- J 1864: Chem. News. Zeitsch. anal. Chem,. 3, 272. ESTIMA TION OF CARBON AND HYDROGEN. 215 tions, in several very thin bulbs, which, by holding a hot clay shield near, are made to burst in the filled combustion- tube, either while only copper oxide in the front is heated, or before heating 2 1 6 ELEMENTA RY ANAL YSIS. at all. Less volatile liquids, introduced in open tubes, may be intermixed with the oxide of copper by applying a single stroke of the exhausting syringe to the tilled combustion-tube, causing the liquids to boil. Combustion-tubes of good length and width are required, with evenly coarse granular copper oxide filling the tube without a channel. Care is exercised to avoid explo- sions and the escape of unburned vapor. It is desirable to shield the combustion-tube under a firm cover of copper gauze. Gaseous bodies are subjected to the special methods of Gas Analysis for elementary estimations. These methods depend most- ly upon volume measures of the gases, with measures of the residues after their absorption, and the products of their combustion. Such a volume measure of the residue after absorption is made in the chief method of the analysis of solids for nitrogen, as described in the pages following. In the first elementary analysis of fixed bodies, by Lavoisier, the products of the combustion were mea- sured in volume for the calculation of weight. Methods of or- ganic analysis for carbon, founded on gas measurements, have been reported upon by SCHULZ (1866) and others. Gases may be subjected to the method employed for the relative determination of the carbon and nitrogen of fixed substances, by volume mea- surement after combustion, as devised by Liebig, Bunsen, Mar- chand, and others. The combustion in a platinum boat, with gaseous oxygen and copper oxide, may be conducted, for a non-volatile substance, as follows : The furnace should have a secure, level, concave support for the combustion-tube. The furnace of GLASER (Fig. 16) has gutter-shaped iron supports, which may be placed together to form a continuous canal. The combustion-tube, of 12 or 14 mil- limeters (near \ inch) internal diameter, and preferably 4 or 5 centimeters (1J or 2 inches) longer than the furnace, is open at both ends, with fused edges and" tubulated rubber stoppers. The platinum boat is of size to easily enter the tube. The oxide of copper, granulated, is taken cold. Copper gauze and wire are provided, the gauze in pieces about 2 centimeters (} inch) wide, rolled in plugs large enough to fit with easy friction in the com- bustion-tube, and cleaned by momentary ignition in a Bnnsen flame. One of these plugs is pushed about 25 centimeters (10 inches) into the tube ; from the other end the coarsely granular copper oxide is filled to within 6 to 8 centimeters (2 to 3 inches) of the opening, settling it by very slight tapping, following which is inserted another plug of the copper gauze of sufficient length, leaving a free space between it and the rubber stopper. 1 1 A spiral of copper wire is used, forward of the plug, by some them- ESTIMATION OF CARBON AND HYDROGEN. 217 A shield of copper foil is put over this end (Fig. 16). A piece of copper gauze about 10 centimeters (or 4 inches) wide is rolled about a stiff copper wire of sufficient length, doubling a bit of the wire down firmly upon the first turn of gauze, and rolling the gauze to make a plug to fit the tube easily, when the free end of the wire is bent, forming a ring which will enter the tube, in which it is placed after igniting it for a moment. The gasome- ters for oxygen and for air are filled, and connected with an apparatus for removing moisture and carbon dioxide. Each gasometer may be connected with a separate bottle of potassium hydrate solution, from which" both connections may lead to a single deep U-tube filled with coarsely granular soda-lime, and then successively to three deep U -tubes filled with small lumps of dry fused calcium chloride. A U-tube containing pumice-stones wet with concentrated sulphuric acid may also be interposed at any point after the soda- lime. See Fig. 16. A mercury- valve (Fig. 17) ffi Fig. 17 is sometimes interposed between the combustion- tube and the purifying apparatus to prevent dif- fusion of products of combustion backward. A good chloride of calcium U-tube, with bulb on the horizontal part next the combustion, is filled ; also the Geisler potash bulbs (Fig. 11) with the potash tube ; and a bell-jar as- pirator (Fig. 16) is provided, carrying a chloride of calcium tube. The apparatus being put in place with the combustion-tube over the furnace, without the platinum boat, the tube is heated up throughout, and a slow current of the dry air is transmitted through the combustion-tube alone. Meanwhile the calcium chloride tube and the potash bulbs and tube are weighed with- out their caps, and then closed. When the column of copper oxide has been heated for ten or fifteen minutes the heat is turned down, the platinum boat is ignited and then cooled in a desiccator and weighed, and from 0.3 to 0.5 gram of the substance is trans- ists. All the metallic copper becomes coated with copper oxide during the heat- ing in the stream of oxygen or air, and the copper oxide so formed makes an efficient oxidizing agent for the gaseous products of incomplete combustion. However this anterior end of the tube be filled, it is advisory to have a free space of 2 or 3 centimeters (an inch or more) next the caoutchouc stopper. 218 ELEMENTAR Y ANAL YSIS. ferred to the boat. The weight may be taken in the boat, or, if the substance be affected in any way by exposure, the substance is added from a stoppered tube, weighed before and after it is taken (p. 208). The air-current is stopped ; the chloride of cal- cium tube and the potash bulbs and tube are securely connected by caoutchouc tubes of clean inner surface, and the aspirator is connected in place. The stopper at the posterior end of the combustion-tube is taken out and the copper-gauze cylinder with- drawn, the platinum boat is inserted in its place near the short copper-gauze plug, the cylinder and posterior stopper replaced , and the connections made with the purifying apparatus and gasometers. The aspirator- valve is opened a little, a few burners nearest the chloride of calcium tube lighted and gradually turned up, and the heat increased to dull redness, not sufficient to distort the tube, and extended back to a safe distance from the gauze plug governing the aspirator to take out the expanded air. The diminished gaseous tension within the apparatus tightens the connections. A difference of 12 to 15 centimeters (about 5 inches) in water level of the bell-jar aspirator is usually main- tained. The gauze cylinder is now gently heated, and at about this point the stream of air may be exchanged for one of oxygen, running at first not faster than a bubble every two seconds. The space next the anterior stopper is kept dry without softening the rubber, and the heat is brought back to within 4 or 5 centimeters (1 or 2 inches) of the platinum boat, when a gentle heat is turned up directly underneath the substance. The progress of the combustion is observed, and the heat so regulated by the changes in the substance and the bubbling in the potash bulbs as to obtain a gradual and even progress. When the substance is completely charred, and the bubbling through the potash solution abates, the heat under the boat is increased and the How of oxygen quickened to about one bubble per second. The exchange of oxy- gen for air may be delayed till the substance is charred. When the carbonaceous matter in the boat has disappeared, the heat underneath it is lessened and the stream of oxygen quickened ; soon after which the heat is partly turned down all along the tube, and the stream of oxygen exchanged for one of air. In a few minutes now the gasometer and aspirator may be shut oft', and the potash bulbs and tube and the chloride of calcium tube at once detached, closed at their openings, wiped, and weighed (without their caps). The platinum boat may be weighed for estimation of ash. The combustion-tube is cooled very gradually, and is at once ready for another combustion, with the same copper oxide, free from moisture. The water in the bulb of the chloride ESTIMA TION OF CARBON AND HYDROGEN. 219 of calcium tube is examined as to its purity, freedom from empy- reuma, etc. Liquid substances are weighed in bulbs or small tubes, as described on p. 213, placed upon the platinum boat, and subjected to combustion as above directed. Volatile substances are expelled from the bulbs containing them before the posterior portion of the copper oxide is heated, a hot clay shield being held over the boat for that purpose. The relations of these substances to elementary analysis have been stated further on p. 214. ESTIMATION OF CARBON AND HYDROGEN IN NITROGENOUS COM- POUNDS. The presence of nitrogen requires only such a change in the conditions of the combustion as shall prevent acidulous oxides of nitrogen being formed and carried into the potash bulbs to increase their weight. This is done by passing the products of combustion over metallic copper at red heat. The preparation of copper for this purpose is described on p. 204. In combustion of nitrogenous compounds with copper oxide, as directed on pp. 208, 211, the combustion-tube is to be 12 to 15 centimeters (about 5 inches) longer than required for a non- nitrogenous body. A roll of copper foil about 12 centimeters (near 5 inches) long is prepared as directed on p. 217, heated in hydrogen gas (p. 204), and placed in a drying-oven at 100 C. The combustion-tube is iilled in the ordinary way, leaving room for the gauze roll, which is introduced while warm from the drying-oven. Before the mixture of substance and copper oxide is heated in the tube the metallic copper is brought to a bright red heat, and so maintained during the combustion. If gaseous oxygen be supplied at the close of the operation, it is supplied sparingly, so as not to oxidize all the metallic copper until, near the close of the combustion, the nitrogen shall have been expelled, and only carbon remain to be burned. In combustion of nitrogenous bodies, for carbon and hydro- gen, in a stream of oxygen gas, the gauze copper roll of about 12 cm. length, as above described, is Inserted in a space left for it in the anterior end of the combustion-tube (p. 216), chosen longer on this account. The copper oxide is first dried, in the heated tube, in a stream of dry air (p. 202) ; then the air is turned off, the roll of metallic copper warm from the drying-oven intro- duced into its place, the platinum boat with the substance inserted, the connections made, and the combustion commenced. The stream of air is not changed for one of oxygen until the continu- ance of the combustion demands it ; and neither is used in such excess that the metallic copper becomes oxidized before the nitro- 220 ELEMENTARY ANAL YSIS. gen has all passed out. To burn out the last traces of carbona- ceous residue the stream of oxygen may be used freely. The roll of metallic copper is used but once. ESTIMATION OF NITROGEN IN CARBON COMPOUNDS. Absolute determination ~by volume of the gas. Of various serviceable methods for this estimation, the following are here presented : Method of JOHNSON and JENKINS/ based in good part upon Dumas's Method. The substance is burned in mixture with copper oxide, and, by help of oxygen generated from potassium chlorate, put in the rear of the combustion-tube, the gaseous pro- ducts being all carried through a porous column of heated metal- lic copper of length sufficient not only to deoxidize nitrogen oxides but to absorb all the excess of oxygen. A short layer of heated copper oxide, front of the metallic copper, oxidizes any hydrogen held occluded by the metallic copper, also traces of carbon monoxide formed by the metal. The gases are received in a measuring-tube (azotometer), over potash solution, which they pass through, and which absorbs all carbon dioxide, nitrogen being left alone as a permanent gas, measured for quantity. Between the combustion-tube and the azotometer is introduced a mercurial air-pump, by which the combustion-tube is first fully exhausted of air before the combustion, and by which the gaseous products left in the tube after combustion are drawn out and delivered to the azotometer. 2 During the combustion the gases pass through the pump to the azotometer. After the initial ex- haustion of the combustion-tube, carbon dioxide is generated in it by heating a short column of sodium bicarbonate placed in the very front of the tube, this carbon dioxide, like that formed in 1 S. W. JOHNSON and E. H. JENKINS, 1880: Am. Chem. Jour., 2, 27; Zeitsch. anal. Chem., 21, 274; Chem. News, 47, 146. A valuable report on Prof. John- son's method is given from continued experience in its use, in comparison with the Ruffle Method, by C. S. DABNEY, JR., and B. voi: HERFF, 1885: Am. Chem. Jour., 6, 234. Also, valuable improvements in the pump, and a modification of the charging of the combustion-tube by T. S. GLADDING, 1882: Am. Chem. Jour., 4, 42 (illustrated). The "Official Methods of the Association of Agri- cultural Chemists for 1886-7" are given in Bulletin No. 12, Department of Ag- riculture, Washington, 1886, p. 52. Modifications of Dumas's Method are also given by G. S. JOHNSON, 1884: Chem. News, 50, 191; Jour. Chem. 8oc., 48, 189; and by ILINSKI (with ordinary laboratory apparatus), 1884: Ber. d. chem. Cres., 17, 1347; Zeitsch. anal. Chem. ,24, 76. 2 DABNEY (see last foot-note) says: "For getting the air, before combustion, and the nitrogen afterward, out of the tube, we have used carbon dioxide with- out a pump and have obtained excellent results. . . . Magnesite or manganese carbonate, put in the back end of the tube, are the best sources for this pur- pose. [See, following, SIMPSON'S Method.] But more time is consumed in this way than with a good, fast-working, tight pump." ESTIMA TION OF NITROGEN. 221 combustion, being taken up in the azotometer by the potash solution. The copper oxide is directed to be made by heating copper scale with 10 per cent, of potassium chlorate and enough water to make a thin paste, stirring till dry. and igniting until the mass does not glow when stirred. The potassium chloride is to be washed out by decantation, and the copper oxide dried and mode- rately ignited. Metallic copper is used as fine copper gauze in rolls to fit the combustion-tube, or as granular oxide of copper reduced and cooled in a stream of hydrogen (p. 205). Potassium chlorate is prepared by fus- ing the commercial article in a porce- lain dish and pulverizing when cold. Sodium bicarbonate is used, and must be free from organic matter. /Solution of potassa is made by dissolving com- mercial potash in sticks in less than its weight of water, and permitting the excess to crystallize out when cold. The same solution may be used a num- ber of times. The combustion-tube, of best hard glass, should be about 28 inches (71 centimeters) long. The rear end is bent and sealed as in Fig. 20. It is best to protect the horizontal part with thin sheet copper or copper gauze, as directed further on. . The azotometer, Fig. 18, is a modi- fication of SCHIFF'S/ The gas is mea- sured in an accurately calibrated bu- rette, A, of 120 c.c. capacity, graduated to fifths c.c., and closed at the upper end by a glass stop-cock. The lower end is connected, by a perforated stopper about 1} inches (4.5 centimeters) long and 1J inches (3.8 centimeters) in diameter, with another tube, which has two arms, one, D, to receive the delivery-tube from the pump, the other to connect by a rubber tube with the bulb, F, of 200 c.c. capacity, for the supply of potash solution. The burette is enclosed in a water- jacket of about 1} inches (4.5 centimeters) external diameter. Its lower end is closed by the rubber stopper that connects the burette with the two-armed tube below. The upper end of the 1 1868: Zeitsch. anal. Chem., 7, 430. See also ibid , 1881 : 20, 257. 222 ELEMENTAR Y ANAL YSIS. jacket is closed by a thin rubber disk slit radially and having four perforations : one in the centre admitting the neck of the burette, and three others near the circumference. Through one of the latter a glass tube, L, bent as in the fig- ure, reaches to the bottom of the jacket, another short tube passes through the disk (these tubes conveying water to and from the jacket), and the third hole supports the thermometer. The azotometer is held upright and firm on a stand by rings fitted with cork wedges around it. The bulb for the potash solution rests in a slotted sliding ring. The air-pump* used by Prof. Johnson is a Sprengel mercury-pump, modified so as to be easily constructed and durable. It is shown in outline, with some parts enlarged, in Fig. 19. Through a rubber stopper wired into the nozzle of the mercury reservoir, A, passes a glass tube, B, 4 inches (10.2 centimeters) long, and this connects by a stout rubber tube, C, with the straight tube, D, 3 feet (91.4 centimeters) long. The stout rubber tube, E, 6 inches (15.2 centimeters) long, connects D with a straight glass tube, F, of about tlfe same length as D. G is a piece of combustion-tubing, 1 J inches (3. 8 centimeters) long, closed below by a doubly Kg, 19 perforated soft rubber stopper admitting the tubes F and H, and above by the singly perfo- rated rubber stopper into which the tube I is fitted. The tube H has a length of 45 inches (114.3 centimeters). At the bottom it is con- nected by a fine black rubber tube (previously soaked in melted tallow) with a straight tube of 3 inches (about 7 centimeters), and this again in the same way with the tube K, of 7 inches (about 18 centimeters) length. The tubes H and K should have an internal diameter of 1.5 millimeters, F may be 2 millimeters, and D still larger. For H and F may be used slender Bohemian glass tubes of 4 millimeters external diameter. Their elasticity compensates for their slenderness. If heavy barometer tubes be used the stoppers and G must be of correspondingly larger dimensions. The joints at G must 2 A mercurial pump for nitrogen is also figured and described by DABNEY, 1885: Am. Chem. Jour., 6. 236. ESTIMA TION OF NITROGEN. 223 be made with the greatest care. It is best to insert the lower stopper for half its length into G, and F and H should fit so snugly as to be inserted with effort when oiled. The tube I must be of stout glass, about a centimeter (0.4 inch) in diameter, and drawn at both ends to a gradual taper, the outer end bent to connect with the combustion-tube, the inner end when oiled turned into a perforation of about 0.5 centimeter (0.2 inch) in the upper stopper. The joints entering G are the only ones having to resist pressure into vacuum, and they must be made with the utmost care. If not secure without, they are to be trapped with glycerine. To do this pass F and H through a stopper of J inch (or 13 millimeters) greater diameter than G and placed below it, when, before inserting I, a jacket-tube 4 inches (10 centimeters) long is fitted upon this stopper, surrounding G. After I is in- serted the trap is ready, to be filled with concentrated glycerine, which is preserved from dilution by adding a stopper to the outer tube, around I, split in halves for adjustment. The two rubber tubes are both provided with efficient screw-clamps to govern the flow of mercury. The tubes D, F, H, and I are secured by cork clamps and wires, or otherwise, to an upright plank, which is framed below into a heavy horizontal wooden foot on which rests the mercury-trough. The plank carries above a horizontal shelf for the support of the reservoir, A, the neck of which rests in a perforation in the shelf. At the' fastenings of the tubes upon the upright support thick rubber tubes are interposed as elastic rests. The rubber tube joints should be wound with waxed silk. A glass funnel is used in A to prevent spattering of the mercury. JKCI0 3 j MIXTURE 'RINSINGS! Cu. jCuOj c % a I ASBESTOS j idem.! 30 cm. Idem. 12 cm.J5cm.j3cmi 10 cm. J rig. 20 The combustion -tube is charged as follows : Of the potas- sium chlorate from 3 to 4 grams, according to the amount of carbon to be burned, are placed in the tail of the tube, Fig. 20, followed by a plug of ignited asbestos just at the bend. Of the substance under analysis 0.6 to 0.8, gram, from the weighing- tube, is well mixed in a mortar (previously rinsed with the copper oxide) with dry (recently ignited) oxide of copper enough to fill 11 or 12 inches (28-30 centimeters) of the tube, and the mixture introduced through a funnel. The rinsings of the mor- 224 ELEMENTAR Y ANAL YSIS. tar with oxide of copper are added to fill about 3 inches (7. 6 centimeters) of the tube, and a second asbestos plug placed. On this is placed the reduced copper for 4 or 5 inches (10 or 12 centimeters), then a third asbestos plug, then 2 inches (5 centi- meters) of the copper oxide, and a fourth plug of asbestos, fol- lowed by 0.8 to 1.0 gram of the sodium bicarbonate. 1 The re- maining space is loosely filled with asbestos to take the water of combustion and prevent it from flowing back upon the heated glass. The anterior part of the tube is wound with copper foil, leaving the rear of the metallic copper visible. The filled com- bustion-tube is placed in the furnace, on a level with the tube, I, of the pump (Fig. 19), and carefully connected with the latter by a close-fitting rubber stopper moistened with glycerine. The azotometer is prepared and tested as follows : The bottom is fill- ed with mercury to about the level indicated by the dotted line Gr (Fig. 18). The arm D is securely closed by a rubber stopper. The stop-cock H is greased, the plug inserted, and the cock left open* The potash solution is poured into F until A is nearly full, and some solution remains in the bulb F, which is now raised care- fully in one hand, while the other hand is upon the stop-cock H. When the solution has risen in A very nearly to the glass cock, the latter is closed, avoiding contact of the alkali with the ground glass bearings, when the bulb is replaced in the ring and lowered as far as may be. If the level of the solution in the azotometer does not fall in 10 or 15 minutes, it is tight. The pump is set in operation by putting its delivery-tube K in a trough of mercury, supplying the reservoir, A, with at least 500 c.c. of mercury, and cautiously opening the clamps C and E. If the mercury does not start at once, repeatedly pinch the rub- ber at E. It should flow nearly as fast as it can be discharged at K, and without filling the cylinder G. A complete exhaustion 1 GLADDING (1882: Am. Chem. Jour., 4, 45) dispenses with chlorate of pot- ash, and puts about 0.6 gram bicarbonate of soda in the tail of the tube (1). The space 2 is filled with about two inches of ignited asbestos. The substance at 3 is mixed with copper oxide, as fine as sea-sand, without dust. At space 4 is another 0.6 gram of the bicarbonate; then is placed a layer of copper shot, and again a layer of coarsely granulated copper oxide (6). The analysis is begun by drawing the potash solution nearly to the top of the azotometer, then turning up lamps under 6, and at the same time starting the pump. When a perfect vacuum has been obtained and the copper oxide (6) is red hot, the lamp just beyond 1 is turned up, and a gentle heat, just sufficient to drive off the carbon dioxide from it and not to heat space 3, is applied. When the tube is full of carbon dioxide this lamp is turned off and the tube again exhausted. By this process of washing out the tube several tenths of a c.c. of additional gas are obtained and almost the last traces of air removed. On running the heat back the bicarbonate at 4 gives off carbon dioxide, and refills the tube before the combustion of the substance at 3 begins. ESTIMA TION OF NITROGEN. 225 of the combustion-tube can generally be obtained in 5 to 10 minutes' working of the pump. If the mercury becomes ex- pended before the desired exhaustion is obtained, the clamp C is closed and the mercury returned to A. Complete exhaustion is denoted by a clanking or rattling sound of the falling mercury, and a half a minute after this is heard the clamp C may be closed. If the mercury column in H remains stationary for some minutes, the connections are tight. The mercury trough is closed and the tube K placed in a capsule. Before connecting the azoto- meter, heat is applied to the part of the combustion- tube contain- ing the bicarbonate of sodium. Water-vapor and carbon dioxide are evolved, filling the vacuum in the pump and displacing the mercury in the tube H. The azotometer is placed at hand, its bulb F is taken from the ring and supported in a box near the level of the tube D, the stopper of which is now removed with- out greatly changing the level of the mercury (G). The tube D is filled half full or more with water. As soon as the mercury lias fully escaped from the pump-tube K, this is inserted in the azotometer-tube D. A few bubbles are allowed to escape through the water, and then the tube K is passed down so that the gas escaping from the pump enters the azotometer. It w T ill facilitate the delivery of the gas if the extremity of the pump- tube just touches the inside of the azotometer-tube, as near as possible to the surface of the mercury. The carbon dioxide is absorbed in passing through the caustic potash solution, and no permanent gas should be obtained. In spite of all precautions very minute bubbles of permanent gas will occasionally ascend, but, as will be seen on observing the amount of potash solu- tion so displaced, the error thereby occasioned is extremely small. In the combustion the anterior cupric oxide is first heated to full redness, and then the metallic copper. Then the com- bustion of the substance is steadily carried on, so that the flow of gas into the azotometer is about one bubble a second, or a little faster. When the horizontal part of the tube has all been heated, and the evolution of gas has nearly ceased, the potas- sium chlorate is heated so as to boil vigorously with genera- tion of oxygen. Any remaining carbon of the substance now burns rapidly, and the reduced copper oxide is promptly reox- idized. When the layer of metallic copper in the anterior part of the tube begins to be oxidized, the generation of oxygen is stopped and the heat lowered all along the tube, keeping the metallic copper still at faint red heat. After a few minutes now the pump is started, slowly at first, having some vessel 226 ELEMENTAR Y ANAL YSIS. under the azotometer-tube D to receive the mercury. A few minutes' pumping suffices to clear the tube, full exhaustion be- ing indicated as stated on p. 225. l The azotometer is now removed from the pump, the azoto- meter-tube D is closed by its rubber stopper, the bulb (F) is raised in its ring to such a height that the potash solution in it is nearly on a level with that in the burette, the filling-tube L is connected with water-supply, a thermometer is inserted in the top of the water jacket, and the water allowed to run until the temperature and the volume of the gas are constant. The level of the solution in the bulb is now accurately adjusted to that in the burette, and the temperature and the volume of the gas are read, as also the height of the barometer. "When 50 per cent, potash solution is used no correction for tension of aqueous vapor is used by Prof. Johnson, following the authority of SCHIFF.* The volume read off is reduced to volume at C. by divid- ing by 1 + (degrees temperature C. observed X 0.003665). That c.c of observed volume 1S ' 1 + (observed temp. C. X 0.003665) = C ' C ' V lume at " The volume at observed barometric pressure is reduced to volume at 760 millimeters barometric pressure by the (inverse) proportion, 760 : mm. of observed pressure :: c.c. observed vol. : x = c.c. at 760 mm. At C., and 760 mm. bar., 1000 c.c. of (dry) nitrogen weigh 1.25616 grams. The corrections, therefore, may be stated: mm. bar. X 0.0012562 -u 4. , -, t : A (1+ 0.00367 T) 760 = &"* Wei ^ ht f * C ' C * at T tem Pemture. The value of this fraction is given in a table for T to 30, by J. T. BKOWN: Jour. Chem. Soc., [2], 3, 211; Wattes Diet. Chem., vi. 147. Correction for temperature, pressure, and water-vapor tension is made by the formula : 1 See GLADDIIS'G, under p. 224. 9 HUGO SCHIFF, 1868: Zeitsch. anal. Chem., 7, 432. This author found in several determinations that air dried by passing through a 50 per cent, potash solution, at 24 C., still contained only 108 to 113 milligrams water in 19 liters. This would give to nitrogen a reading about 0.007 of its volume too high. His determinations of nitrogen, by his procedure in the absolute method, were uniformly a little too low, thus: 12.9 instead of 13.2; 31. 4 instead of 31.8; 9.0 to 9.1 instead of 9.1; 3.8 to 3.9 instead of 3.9. The deficiency he ascribed to retention of traces of nitrogen oxides. And the author advises to neglect the correction for aqueous vapor, in compensation for the margin of loss. ESTIMA TION OF NITROGEN. 227 P = 0.0012562 X V X . o 367 ^ Wherein P = the grams weight of the nitrogen measured. V = c.c. of observed volume. T = temperature of the azotometer-jacket in de- grees C. B millimeters of barometric reading. f = tension of water-vapor, at T, found in milli- meters. Of the tables convenient for consultation, to shorten calcula- tions for nitrogen, are those of BATTLE and DANCY, for use in Analysis of Commercial Fertilizers, 1885 : North Carolina Ex- periment Station, Raleigh, N. C. Also, for general uses, KOHL- MAN und FRERICHS, " Rechentafeln," 1882 : Leipzig. The correction for water -vapor tension is purposely neg- lected by some chemists, on the ground (already mentioned) that strong potash solution leaves the gas nearly dry. 1 On the other hand, the results by Johnson's procedure in absolute method for nitrogen are more apt to be over than under the true quantity (see the citation from DABNEY, under Ruffle's Method). When the correction is required it is made as follows : Consult a table of Tension of aqueous vapor at various temperatures (this tension being irrespective of pressure), and find the tension, in height of mercury, for the observed temperature. Subtract this tension from the barometer reading in the operation in hand, as in the formula above. Method of Maxwell Simpson (1855). Combustion by a mix- ture of copper oxide with mercury oxide, the tube having been cleaned of air by a current of carbon dioxide liberated by heat- ing a carbonate. The excess of oxygen is taken up by a good quantity of heated metallic copper in the combustion-tube; the carbon dioxide by potash solution in a receiver ; and the nitrogen is measured over mercury for the calculation of its weight. The mercuric oxide is to be prepared by precipitation with fixed al- kali, washing with water and then with dilute phosphoric acid, and drying at 100 C. The combustion-tube, about 80 centi- meters (31.5 inches) long, is closed in a rounded end by fusion. 1 Owing to the fact that the strength of the potash solution varies, and the water-vapor tension is therefore uncertain, GALTERMAN (1885) collects the ni- trogen over potash solution in a non-calibrated tube, thence transferring it to a measuring-tube over distilled water. The full tension of the water-vapor is deducted. 228 ELEMENTAR Y ANAL YSIS. A mixture of 12 grams of manganese carbonate or of magnesite, previously dried at 100 C., with 2 grams of the mercuric oxide, is introduced into the tube. A plug of recently ignited as- bestos is inserted, pushing it down to within 3 centimeters (about 1 inch) of the mixture, and next is added 1 gram of the mer- curic oxide. Of the substance under analysis about 0.6 gram is taken, from a weighing-tube, for intermixture in a mortar with 45 times its weight of a prepared mixture of 4 parts of finely pow- dered and recently ignited copper oxide, with 5 parts of the dried mercuric oxide. The whole is transferred to the combustion- tube, the mortar is rinsed with some more of the mixed oxides, and the rinsings added. A second plug of ignited asbestos is pushed down to within about 30 centimeters (near 12 inches) of the first, leaving the mixture of oxides loose ; a layer of 6 to 9 centimeters (2J-3J inches) of the copper oxide is added and a third plug of asbestos placed ; and lastly a layer of as much as 20 centimeters (near 8 inches) of metallic copper, prepared by reducing granular copper oxide in a stream of hydrogen at low temperature (or in a stream of carbon monoxide). The com- bustion-tube is now drawn out and turned down, and connect- ed by a section of rubber tubing with a delivery-tube adapted to reach beneath the surface of mer- cury in the trough. The combustion-tube is tapped on the table to form a channel for the escape of the gases, and placed in the furnace. A receiver is provided, as shown, with the trough of mercury, in Fig. 21. The receiver has about 200 c.c. capacity ; the glass stop-cock should enable it to hold mercury when filled with it and set up in place ; a delivery-tube is firmly connected with its neck, and it is tubulated on the side near its base. This tubule carries an upright filling-tube, with contrac- tion near the tubule. It is filled with mercury, placed in the trough with the tubule under the mercury, and about 20 c.c. of strong solution of potassium hydroxide passed into it. A meas- uring-tube for the nitrogen gas is represented in Fig. 22. But instead of both the receiver and measuring-tube here described, the azotometer figured on p. 221 may be used. About half of the carbonate in the posterior end of the com- ESTIMA TION OF NITROGEN. 229 bustion tube is heated, so that the air is driven out by a current of carbon dioxide ; and at the same time a part of the tube oc- cupied by the metallic copper and the copper oxide is heated. The escaping gas is tested for air, from time to time, by receiv- ing a few bubbles in an inverted test-tube containing solution of potash ; and when the bubbles are completely taken up by the solution, and the anterior part of the tube is well heated, the delivery-tube from the combustion is inserted in the lateral tubule of the receiver. The substance in mixture with the oxides is now gradually heated, beginning next the clear copper oxide, until the whole tube, except that occupied by carbonate in the rear, has been at full heat, and no further delivery of gas is ob- served. Next, the remain- der of the carbonate is heated, so as to sweep out the nitrogen remain- ing in the tube. The delivery-tube is now withdrawn from the re- ceiver, which is left for an hour for the absorp- tion of the last traces of carbon dioxide. The nitrogen gas is transferred to the measur- ing-tube, Fig. 22. The stopper inserted into the lateral tubule of the receiver is moistened with mercuric chloride solution to prevent its carrying in air. A drop of water is placed in the measuring-tube before it is filled with mercury and inverted in the cistern. The stop-cock in the neck of the receiver is care- fully governed to obtain a very gradual delivery of the gas, and is closed each time that the mercury is poured into the filling- tube, below the contraction in which the mercury is not permit- ted to fall in the beginning of the transfer. Close the stop-cock as soon as it is reached by the potash solution, leaving the ni- trogen in the delivery-tube to compensate for the air it contained to begin with. For calculation of weight from volume, with corrections for temperature and pressure, see p. 226. A VERY SIMPLE METHOD FOR ABSOLUTE DETERMINATION OF NITROGEN, when carefully conducted, will give good results. 230 ELEMENTAR Y ANAL YSIS. An operation as follows, with copper oxide as the sole supply of oxygen, with SchifFs azotometer, and without a pump, will give true results, though requiring more time than the method of Johnson or that of Simpson. The copper oxide is dried by ignition in a current of dry air in a combustion-tube with bayo- net-end. In a combustion-tube of good length, closed (with round end) at the rear, a layer of manganese or magnesium carbonate is placed first, as stated on p. 228, then a plug of as- bestos, then a short layer of copper oxide, then the substance mixed with copper oxide, mixing in a mortar or in the tube. About two-thirds of the tube should remain for the layers of copper oxide and metallic copper. The latter may be a roll of ignited copper gauze or a layer of reduced granular oxide, and should be 5 to 8 inches long. Anterior to this may be, as pro- posed by Professor Johnson, a short layer of copper oxide to oxidize any occluded hydrogen. In the combustion the air is first expelled by liberating car- bon dioxide from a part of the carbonate in the rear ; the ante- rior layers of metallic copper and copper oxide are kept at full red heat ; the substance is burned very slowly, and much time is taken in oxidizing the last of the carbonaceous residue ; and finally the tube is swept out by ignition of the remaining car- bonate in the posterior end. The gases from the tube are re- ceived directly into a SchifFs azotometer, over strong potash solution. In measuring the nitrogen, the room and apparatus being of uniform temperature, a thermometric reading is ob- tained. ESTIMATION OF ORGANIC NITROGEN BY ITS CONVERSION INTO Ammonia. The So da- Lime process of Varentrapp and Will. The nitrogen of nitrates is not included in this estimation. The substance is heated in a combustion-tube in mixture with soda- lime, the products being carried through a. layer of red-hot soda-lime of at least half the length of the tube, and received in a solution of acid. The ammonia remaining in the tube after the combustion is swept out by burning a short layer of oxalic acid in the rear, also by aspiration. If the substance be rich in nitro- gen it is diluted with cane-sugar. The gaseous ammonia from the combustion-tube is received in a known volume of a standard solution of oxalic or sulphuric acid, which is afterward titrated (PELIGOT'S modification) ; or is received in hydrochloric acid for gravimetric estimation with platinic chloride. Using Peligot's modification, Prof. S. W. JOHNSON found 1 that, with various '1879: Am. Chem. Jour., I, 75; 1872: Am. Chemist, 3, 161. ESTIMA TION OF NITROGEN. 231 substances, under a series of determinations, " the soda-lime pro- cess is, to say the least, equal in accuracy with the absolute determination," by volume of free nitrogen. At bright red heat r with soda-lime, ammonia is not decomposed. A combustion-tube of 14 to 30 inches (35 to 75 centimeters) length, and near J inch (10 to 12 millimeters) width, is sealed round at one end (Fig. 23). The Erlemneyer's gas-furnace is the most convenient. The best bulbed U- tube is that shown in the figure. The acid is of about normal strength, titrated with an alkali solution of about half -normal, the latter being exactly valued with a standard acid solution prepared with care. Prof. S. W. Johnson uses standardized hydrochloric acid and standard solution of ammonia, and titrates with cochineal tincture as an indicator. The same indicator should be used in all titrations ; and if the acid solution become colored from the combustion, litmus tincture is not applicable. Litmus-papers, blue and red, serve very well. The soda-lime, preferably granulated, otherwise coarsely powdered, is heated to remove all moisture, which is strictly excluded until the article is used. It may be used warm if the substance is stable enough to suffer no change therefrom. Oxalic acid should be heated on the water-bath to remove all water of crystallization. Asbestos^ recently ignited, is required. In the charging of the combustion-tube a layer of about 1 inches (3 centimeters) of the dried oxalic acid is intro- duced into the rear of the tube, followed by about the same length of soda-lime. The substance under analysis is added from the weighing- tube, in quantity about 0.5 gram, to some of the soda-lime in a mortar (previously rinsed with the soda-lime), and a mixture made which, with the rinsings of the mortar, will fill the tube to a point from two-fifths to one-half its length from the closed end. Or the mixture of the substance with the soda-lime is made in the tube by means of a stirring- wire (Fig. 8), so as to form a layer of near the length just stated. In either case, if the substance be very rich in nitrogen, about an equal quantity of dried cane-sugar may be taken with it in the mixture. The remainder of the tube is filled with the soda-lime to within about 2 inches (5 centimeters) of the rubber stopper, placing a loosely porous plug of the asbestos, nearly an inch (or 2 centimeters) in length, as a secure guard against the carrying forward of alkaline 232 ELEMENTAR Y ANAL YSIS. dust or spray, and leaving a free space next the stopper. A shield may be put over the end of the tube (Fig. 16). The U-tube is filled and connected as shown in Fig. 23. The more that moisture has been excluded from the soda-lime, the easier will be the combustion. But the use of warm soda- lime in intermixture with the substance must not be adopted without assurance that no traces of ammonia are generated in such mixture. If the soda-lime be well granulated, or even coarsely powdered, with fine particles sifted out, it is better not to triturate in making the mixture of the substance, and to do without a channel formed by tapping the horizontal tube on the table, favoring the more intimate contact of empyreumatic gases with the hot soda lime. But if there are layers of fine powder in the tube, a channel must be provided. In the combustion the layer of unmixed soda-lime is first heated, beginning at the anterior end, and increasing and extend- ing the heat at such a moderate rate that the air-bubbles shall not pass out faster than about two to each second. The heat at the anterior end is so graduated as to prevent condensation of water- vapor in the tube, and not to soften the rubber stopper. When the mixture of substance is reached the layer of clear soda-lime must be at full red heat, and so preserved while the fiarnes are advanced backward more gradually than before, delivering only about one bubble every second. The carbonized substance is at last burned out with a full red heat, and when the delivery of fas has nearly or quite ceased the oxalic acid is very gradually eated, so that the carbon dioxide shall not be tumultuously evolved. The carbon dioxide is generated only long enough to sweep out the combustion-tube, when the U-tube may be de- tached. The acid liquid should be as little colored and empy- reumatic as possible. The anterior end of the combustion-tube, in the space in front of the asbestos plug, should not change moistened red litmus-paper. In titrating the acid for the amount of ammonia it has re- ceived, the volumetric alkali is added from the burette directly to the U-tube until the neutral point is very nearly obtained, with litmus-papers or other indicator, not phenol-phthalein. The acid is now transferred to a beaker, with very little rinsing- water, and the titration completed. The value of the alkali solution is found by a volumetric acid of absolute stand- ard. 17 : 14 :: quantity of ammonia : x = quantity of nitrogen. Combustion-tubes with the posterior end drawn out are some- times used, and the residual ammonia obtained by aspiration, or by sending through a current of carbon dioxide. ESTIMA TION OF NITROGEN. 233 The gravimetric determination of the ammonia, as ammo- nium platinic chloride, is done by the ordinary method, as found in works on inorganic analysis, washing the precipitate with alco- hol or ether- alcohol, and igniting in a weighed crucible. 194.4: parts of Pt represent 14 parts of N. Combustion with soda-lime in an iron tube may be done with good results, 1 as the writer has verified. The tube should be about a third longer, and a little wider, than a glass tube for the same combustion. Special precaution is necessary to avoid burn- ing or melting the stoppers. Combustion with soda-lime, sulphur, and thiosulphate. KUFFLE'S METHOD, 1881. Eeduction by a powerful deoxidizer in presence of a strong alkali. Obtains the nitrogen of organic, ammoniacal, and nitric combinations. Carried out in the same way as the Yarentrapp -Will method in Peligot's modification. The method has been well sustained. DABNEY (1885, already cited) found this method, in application to fertilizers containing small amounts of nitrogen, to give results as close as those by Johnson's process for free nitrogen, the latter method giving often a little too high, the former a little too low figures for the nitrogen. Greater precautions are required for bodies rich in nitrogen. Details are presented in the Official Methods of the Association of Agricultural Chemists for 1886-7, Bulletin No. 12, Department of Agriculture, Washington, 1886. RELATIVE DETERMINATION OF THE NITROGEN AND CARBON. Applicable when the proportional quantity of nitrogen is not small, or not less than N to 4 C = 14 of nitrogen to 48 of car- bon. The substance is burned, with copper oxide, and the products passed over hot metallic copper, in a combustion- tube, so as to deliver in a graduated tube the nitrogen and the carbon dioxide. After taking the volume measure of the gases the carbon dioxide is taken up by alkali and measurement taken again. Methods of Liebig, Bunsen, and Gottlieb are employed. THE DETERMINATION OF CARBON, HYDROGEN, AND NITROGEN, in one operation, is described by C. G. WHEELER, 1866 : Am. Jour. Sci., [2], 41, 33. Also by W. HEMPEL, 1878 : Zeitsch. anal. Chem., 17, 409; Jour. Chem. Soc., 36, 278. Eecently by P. JANNISCH and V. MEYER, 1886: Ber. d. chem. Gesel., 19, 949 (preliminary notice). ! See also JOHNSON, 1879: Am. Chem. Jour., I, 82. 234 ELEMENTAR Y ANAL YSIS. THE DIRECT ESTIMATION OF OXYGEN lias been reported upon as follows : BAUMHAUER, 1866 ; MAUMENE, 1862 ; MITSCHERLICH, 1867, 1868; LADENBURG, 1865; CRETIER, 1874. ESTIMATION OF NITROGEN BY COMBUSTION IN THE MOIST WAY. The well-known process published by Prof. WANKLYN in 1877 depends on the conversion of the nitrogen of organic compounds into ammonia by the action of permanganate in a very dilute solution of alkaline. reaction, the ammonia already contained in the substance being previously distilled off. Its value, in water analysis, is relative rather than absolute, and depends upon its applicability to nitrogenous organic compounds in an extremely dilute solution, so that the changes likely to occur in a concen- tration of the water are avoided. For the analysis of pure ni- trogenous compounds various plans of moist combustion have been proposed of late years. Of these the following method has received general commendation from chemists who have reported trials of it a method in which oxidation by adding dry perman- ganate to a concentrated acid solution is preceded by the altera- tive action of hot sulphuric acid of full strength : Moist Method of KJELDAHL.* For bodies moderately rich in nitrogen 0.250 gram is taken ; for bodies with only about 1.5$ of nitrogen 0.7 gram is taken. The substance is placed in a boil- ing-flask of about 100 c.c. capacity, with a long and narrow neck, and of glass capable of resisting the strongest acids. The flask is placed upon asbestos cloth or copper gauze over a lamp supplying a strong heat, 10 c.c. of pure sulphuric acid of full strength is added, and digestion instituted (under a hood) at a temperature only a little below the boiling point of the sulphuric acid. Sulphurous acid vapors escape. To prevent loss by spirting, the flask is somewhat inclined during the effervescence. After the liquid comes to rest the digestion is continued (still near the boiling point, as shown by occasional bumping) until the liquid becomes gradually of light color, and finally entirely clear. To 1 J. KJELDAHL, Carlsberg Laboratory of Copenhagen, 1883: Zeitsch. . Chem., 22, 366; Chem. News, 48, 101; Am. Chem. Jour., 5, 456. FRESENIUS, 1884: Zeitsch. anal. Chem., 23, 553. CZECZETKA, 1886: Monatsch Chem , 6, 63; Jour. Chem. fioc., 48, 688. WILFARTH, 1885: Chem. Cent., 1885, 17; Jour. Chem. Soc., 48, 837. BOSSHARU, 1886: Zeitsch. anal. Chem., 24, 199; Jour. Chem. Soc., 48, 837. C. ARNOLD, 1886: Archiv d. Pharm., [8], 23, 177; Jour. Chem. Soc., 48, 688. Details are defined in the " Official Methods of the Association of Agricultural Chemists," Department of Agriculture, Bulletin No. 12, Washington, 1886. The use of phenolsulphonic acid is introduced into the process by JODLBAUER, 1886: Chem. Cent., p. 433; Jour. Chem. Soc., 49, 834. ESTIMA TION OF NITROGEN. 235 liasten this result a little fuming sulphuric acid or phosphoric anhydride is added. With these additions a digestion of about two hours is usually sufficient. But at 100 to 150 C. the for- mation of ammonia is imperfect and the object not attained. The lamp is now removed, and, while the liquid is hot, finely pulverized potassium permanganate is carefully added, either in very small portions or in a very fine stream, which may be car- ried through a deli very- tube. The reaction is violent, even ac- companied by small names, and it is made as gradually as it can be without interrupting it. When the oxidation is complete a green color appears, and the addition of the permanganate is dis- continued. The liquid may now be warmed for a few minutes, but not on any account strongly heated. The liquid is cooled, and diluted with water, when the green color changes to brown. When again cool the liquid is introduced into a distillatory apparatus, the generating flask holding about f liter, and con- nected with an upward-sloping top-piece to prevent liquid being carried over by spirting, and through the condenser into a re- ceiver containing an accurately measured quantity of acid of known strength. About 40 c.c. of solution of sodium hydrate of sp. gr. 1.30 are quickly introduced into the distilling flask. [A Welter's safety tube may be provided for this purpose.] And to prevent bumping a little metallic zinc is introduced, the hydrogen from which secures an even action. The completed distillate is titrated for the ammonia it has received (as in the estimation of Yarentrapp and Will). Kjeldahl found his method inapplicable to certain alkaloids, cyanides, volatile acids, and nitrogen oxides. It reduces nitrates in presence of organic matter to ammonia, but incompletely (com- pare WARINGTON, 1885 : Ohem. News, 52, 162). Upon the Determination of Total Nitrogen, organic, am- moniacal, and nitrous, see BULLETIN No. 12, Chemical Division, DEPARTMENT OF AGRICULTURE, Washington, 1886, pp. 34, 52. Also, GERMAN MANURE MANUFACTURERS' ASSOCIATION, 1884: H. H. B. Shepherd, translator. Also, HOUZEAU, 1885. RUF- FLE'S method to this effect is referred to on p. 233. BODIES CONTAINING SULPHUR, in estimation of carbon and hydrogen, are subjected to combustion with lead cliromate in- stead of copper oxide, and the front of the column of lead cliro- mate is not heated to full redness. WHEN CHLORINE, BROMINE, or IODINE is present, in combustion to estimate carbon and hy- drogen, a coil of silver wire is placed in the front of the combus- tion-tube to retain the halogens, which otherwise may interfere 236 ELEMENTARY ANALYSIS. with the result. Chlorine forms cuprous chloride, which will condense in the calcium chloride tube. Copper holds chlorine but imperfectly, and the same is true of lead. THE ESTIMATION OF SULPHUR, in organic analysis of com- pounds not volatile, may be done by fusing with potassium hy- drate and nitrate, in a silver dish, until the^mass will be white on cooling. The mass is dissolved in water, acidified by nitric acid, and the quantity of sulphuric acid determined by precipita- tion with barium chloride in the manner required in quantitative work. Volatile compounds can be oxidized with a mixture of sodium carbonate and potassium nitrate in a combustion-tube. Potassium dichromate is also employed as an oxidizing agent in the same way. CHLORINE, BROMINE, and IODINE are estimated by igniting the substance with an excess of pure quicklime, in a narrow combus- tion-tube. The tube is filled with the lime mixed with the sub- stance, followed by a short column of lime alone, and a channel made by tapping the tube on the table. After the ignition the contents of the tube, when cold, are carefully transferred to a flask containing water, and treated with dilute nitric acid, rinsing the tube with the water and then with the acid. The solution is filtered, the residue and filter washed, and the halogens precipi- tated by silver nitrate solution. With iodine it is better to ex- haust first with water, and add silver nitrate solution to the filtrate, then treat the residue with dilute nitric acid and add the acidulous filtrate to the one containing the silver. By this means the liberation of iodine by action of nitric acid is avoided. The silver precipitate is treated as in ordinary quantitative work for the halogens. ESTIMATION OF SULPHUR OR OF HALOGENS is effected by the method of CARIUS * From 0.15 to 0.40 gram of the substance is treated with a calculated quantity of nitric acid sufficient to furnish 4 times the required amount of available oxygen, or of acid of sp. gr. from 20 to 60 times the weight of the substance. The digestion is done in a closed tube, sealed, at 120 to 140 C., for some hours. For estimation of chlorine, silver nitrate is added with the nitric acid before digesting. Details may be found in the original papers and in manuals of quantitative analysis. 1 1860-65: Ann. Chem. Phar., 116, 11; 136, 129; Zeitsch. anal. Chem., i. 217,240; 4,451; 10, 103. DEDUCTION OF CHEMICAL FORMULAE. 237 DEDUCTION or CHEMICAL FORMULAE. In the first place, the molecular weight of the substance is to be ascertained, if possible. (1) If the compound be sufficiently vaporizable its Vapor Density 1 is to be determined and accepted as evidence of the molecular weight. With the weight of air as the unit of gravi- ties, vapor density -X 28. 86 = molecular weight. With hydrogen as the unit, vapor density X 2 = molecular weight. (2) If the substance have a definite capacity of combining, as a base or an acid, its combining number can be determined by its proportions in formation of salts. If an acid, it is needful to ascertain whether it be monobasic, bibasic, or tribasic in its capacities of combination. Certain classes of bases are subject to the corresponding question, whether nionacid or not, but the natural nitrogenous"bases are mostly monacid. (3) If the substance be found to hold a definite relation to other substances, as shown by its formation, its decomposition, or by chemical resemblance to members of homologous series, its molecular weight may be inferred from such relations. If now m be the molecular weight of a compound ; JP, the percentage of a constituent element ; a?, the combining number of this element ; a, its atomic weight, and y, the number of its atoms in the molec^le^ 100 \p\\m\ x. And x + a y. Whether the molecular weight be obtainable or not, an empi- rical statement of atomic numbers can be derived at once from the centesimal figures of the analysis by dividing the percentage number of each element by its atomic weight. The provisional formula so obtained is reduced, by common divisors, to lower terms, and to such terms as best accord with its probable molecu- lar weight, in its apparent classification among compounds of known molecular formulae. Allowances must be made for the real limits of error in analysis, and consideration must be had to the liability of weigh- 1 For ordinary purposes the most ready and satisfactory method of obtain- ing Vapor Density is that of VICTOR and CARL MEYER, 1878: Ber. d. chem. Ges., 10, 2253; Zeitsch. anal. Chem., 19, 214; "Watts's Diet. Chem," 8, 2094. See also reports by V. MEYER, 1876-7: Ber. d. chem. Ges., 9, 1216; 10, 2067; u, 1867; Zeitsch. anal. Chem., 18, 294; 17,373. HOFM ANN'S Method was given in 1868: Ber. d. chem. Ges., I, 198; Zeitsch. anal. Chem.,S, 83. BUNSEN'S Method, 1867: Ann. Chem. Phar., 141, 273: Zeitsch. anal. Chem., 6, 1. Method of TROOST and DEVILLE, 1860: Ann. Chim. Phys., [3], 58, 257. A good summary of the literature of vapor-density determination is given in "Roscoe and Schorlemmer's Chemistry," vol. 3, part 1, p. 84 and after. Also see " Beilstein's Organische Cheraie," 2d ed., p. 17. 238 FA TS AND OILS. able impurities, including moisture, in the article taken for com- bustion. Probable limits of error are represented in general by a comparison of published results of analyses by authorities of credit, and, more definitely, by the experience, of the analyst himself with substances of known composition. Even in empirical formulae the well-known law of conjugate atomic numbers of carbon compounds should be respected, namely, the numbers of the atoms of uneven valence (the perissads, H and N) should together make an even number. Thus in the molecule of morphine, with ^ we have H 19 ; in the molecule of quinine, with !N" 2 we have H 24 . That is, in ordinary non-nitro- genous organic molecules, those containing C, H, and O, or those containing C and H, there is always an even number of atoms of hydrogen. But in nitrogenous molecules (of C, H, N", O, or O, H, JS~) the atomic number of hydrogen is even only when nitrogen presents an even atomic number. The law applies to haloid elements and to phosphorus, when these elements of un- even valence are present. The low atomic weight of hydrogen gives low centesimal dif- ferences for one atom of this element, so that its atomic number is taken as the number which, under the rule, lies nearest the atomic number calculated from centesimals. The establishment of a rational formula for a compound is a work of investigation, both synthetic arid analytic, as obtained by reactions of formation and of decomposition. It requires studies of all chemical relations, led on by analogies from every point of view. An understanding of the chemical structure of the molecule is gained step by step in the investigation. A de- rived chemical formula can be made " rational" only to the extent that the chemical forces of the constituent elements have been revealed in their proportional power. In the study of isome- rides, for the " position " of atoms in molecules, the atomic posi- tion is to be defined as a mode of statement of the chemical functions of the elements. At the same time it may be said that the evidence gained for relative " position " of atoms in a mole- cule is of the same character as the evidence upon which we predicate the existence of the molecule as a whole. FATS AND OILS. 1 Glycerides, and bodies related thereto 1 A good general summary of the chemistry and technology of the neutral fats is presented in the article "Chemical and Analytical Examination of Fixed Oils," A. H. ALLEN, 1883: Jour. Soc. Ohem. Indus., 2, 49. A compact technical summary of the analytical chemistry of fats is presented in BENE- IHKT'S " Analyse der Fette und'Wachsarten," Berlin, 1886, pp. 296. FATTY SERIES OF ACIDS. 239 either by physical properties and uses or by production, are treat- ed in the following pages under the heads here given : Fatty Series, C n H an 2 : Stearic Acid; Palmitic Acid; Myristic, Laurie, Capric, Caprylic, Cajproic acids. Fatty Series, C n H 2ll _ 2 2 : Oleic Acid. Ricinoleic Acid ; Linoleic Acid ; Hypogaic and Physetoleic acids. Fat Acids and Fats, Quantitative Determination of: (1) Hehner's num- ber; (2) Reichert's number; (3) Kottstorfer's number, or capacity of saturation; Tables of Hehner's and Kottstorfer's numbers ; (4) Iodine number of Hiibl ; (5) Mean Molecular Weight; (6) Specific Gravities; (7) Melting and Congealing points; (8) Calculation of Acid and Neutral Fats. Distinctions of Fat Oils by Solubility in Glacial Acetic Acid; Table. Separation of Mineral Oils from. Fats: descriptive list; method by saponi- fication; extraction after saponification, in solution, in dry mass, with Soxlet's apparatus, estimation by Kottstorfer's numbers ; examination of the liquid and solid non-saponifiable bodies. Separation of Fat Acids from Fats. Separation of Resins from Fat Acids. Rosin Oils. Drying and Non-Drying Oils. Linseed Oil; Olive Oil; Cotton-seed Oil ; Castor Oil; Lard; Tallow; Oleo- margarin. Butter: bibliography; constituents; estimation of constituents, of artificial color, or rancidity (acidity); detection of foreign fats by solvents; Scheffer's method ; odor test ; soap viscosity ; microscopical examinations ; butter fat, properties: butter substitutes ; methods of chemical estimation of butter fat Hehner's, Reichert's, Kottstorfer's; interpretation of Hehner's number, of Reichert's, of Kottstorfer's; specific gravity as a means of distinguishing from substitutes; iodine number of Hiibl; scope of butter analysis and forms of certificates, in Massachusetts, in New York, in Pennsylvania, at Agricul- tural Department at Washington; what is a sufficient chemical analysis of butter. FATTY SERIES OF ACIDS, CnH^Og. The folio wing- named members of the C n H2n^2 series are described in this work, and will be found under their respective names. Formic, Acetic, and Valeric Acids are not constituents of Fats. The others are described in the next following pages. For Butyric Acid see p. Y5. ./- Volatile. Formic Acid CH O 2 or H.CO 2 H Acetic Acid C<>H 4 O 2 " CH 3 .CO 2 H Butyric Acid normal. . C 4 H 8 O 2 " CH 3 CH 2 CH 2 .C0 2 H Valeric Acid iso valeric. C 5 H 10 O 2 (CH 3 ) 2 CHCH 2 .CO 2 H Caproic Acid isobutyl- acetic ;. . C 6 H 12 Oo " (CH 3 ) CH(CH 2 ) 2 . CO 3 H Caprylic Acid normal. C 8 H 16 O 2 " CH 3 (CH 2 ) 6 . CO 2 H Capric Acid C 10 H 20 O 2 " CH 3 (CH 2 ) 8 . CO 2 H ? Laurie Acid C 12 Ho 4 O 2 240 FATS AND OILS. Non- Volatile. Myristic Acid C 14 H 28 O 2 Palmitic Acid C 16 H 32 O 3 Stearic Acid C 18 H 36 O 3 STEAKIC ACID. C 18 H 36 O 2 = 284 (monobasic). Found as a normal glyceride in common vegetable and animal fats, in which it is the ordinary constituent of highest melting point. #. Crystallizable from alcohol in white, lustrous tables, or needles ; or congealing from a melted portion in crystalline, translucent masses of considerable hardness. It melts at 69.2 C. At about 360 C. it begins to boil with decomposition of a con- siderable part. Under reduced pressure, at 100 millimeters, it boils at 291 C. With superheated steam it distils with but lit- tle decomposition. Its specific gravity as a solid at 11 C. is that of water at the same temperature, but at higher tempera- tures it floats upon water, and the melted acid just above 69.2 C. has the specific gravity of 0.8454. The melting point can be found, quickly, by immersing the bulb of the thermometer for a moment in the melted stearic acid (free from water), then suspending the coated bulb in the middle of a beaker of water, to which heat is applied, and noting the tem- perature at which the fatty coat melts from the bulb. To purify stearic acid from salts, preparatory to this test, it may be repeat- edly dissolved in alcohol, filtered, and evaporated to dryness. (Further, see Determination of the Melting and Congealing Points of Fatty Bodies, Index.) The normal glyceride, stearin, or " tristearin," C 3 H 5 (C 18 H 35 O 2 ) 3 , is crystallizable, and, when pure, of pearly- white lustre. It melts, according to modification due to previous heat- ing, at a temperature from 55 C. to 71.6 C. Stearin crystal- lized from ether melts at 71.6 C., and then congeals to a crys- talline mass at 70 C. ; but heated only 4 C. above the melting point, it does not then congeal until reduced to the temperature of about 52 C., when it appears as a wax-like mass and will melt again at 55 C. A sample of stearin (not entirely pure), melting at 65.5 C., at this temperature had the specific gravity 0.9245 (BENEDIKT J ). The metallic stearates are fusible bodies, in some instances crystallizable, more often amorphous, and of plaster- like or soap- like consistence. b . Stearic acid and stearins are odorless and tasteless. 1 " Analyse der Fette," Berlin, 1886. STEARIC ACID. 241 c >. Stearic acid is insoluble in water. It is soluble in about 40 parts of absolute alcohol at ordinary temperatures, moderate- ly soluble in 90$ alcohol when hot, very sparingly when cold. On cooling the hot alcoholic solution abundant crystals are ob- tained. It is readily soluble in ether. The solutions redden lit- mus-paper, and decolor the alkaline phenol-phthalein. At 23 C. it dissolves in 4.5 parts of benzene or in 3.3 parts of carbon di- sulphide. Stearin, the neutral glyceride, is insoluble in water, some- what soluble in boiling alcohol, from which it crystallizes out almost wholly when cold. It dissolves in about 200 parts of ether a solubility more sparing than that of the softer neutral fats and dissolves in chloroform, benzene, petroleum benzin, and carbon disulphide. The alkali stearates are somewhat dif- ficultly and imperfectly soluble in water. They dissolve in hot water, with slight turbidity, the solution gelatinizing when cold. On agitating the gelatinized mass with much water in the cold, a turbid mixture is obtained, with formation of difficultly soluble acid stearate along with free alkali. In hot alcohol the alkali stearates are easily soluble, the greater part congealing in the cold, so that only a dilute solution is permanently obtained. The non-alkali metallic stearates are insoluble in water, and for the most part insoluble in alcohol or ether. In some instances, however, they yield free stearic acid to the action of ether. In general they are gradually decomposed by action of water, yield- ing hydrate of the metal and free stearic acid. d. The aqueous solutions of alkali stearates, dilute and turbid, on addition of solution of barium or calcium chloride, or other non-alkali salt, show an abundant precipitate of metallic stearate. An alcoholic solution of stearic acid, with a solution of barium or calcium acetate to which a little alcohol has been added, gives a precipitate of stearate of the metal. The barium precipitate is gelatinous and bulky ; the magnesium precipitate, crystalline and pulverulent. To the action of water these pre- cipitates yield hydrates of barium, etc., while free fat remains behind. The precipitates are to some extent dissolved by boil- ing alcohol, and on cooling the solution crystalline precipitates are obtained. Solutions of alkali stearates are precipitated by addition of dilute acids, the resulting stearic acid appearing in a milky subdivision with curdy clumps. By heating the mixture a clear, oily layer slowly rises, and on cooling solidifies to a crust. Or the precipitate while cold may be filtered out, washed with hot water, drained dry, and dissolved from the filter with hot 242 FA TS AND OILS. alcohol or with cold ether. On evaporation the stearic acid is obtained, crystalline or congealed, as preferred. Also the crude precipitate of stearic acid may be dissolved by shaking out with several portions of ether. e. Separation. Stearic acid is obtained from its glyceride, stearin, by first saponifying with potash, and then decomposing the soap with acid. The saponification is done by boiling gently with alcoholic solution of potassa until a clear solution is ob- tained. Ten parts of the fat are treated with 8 to 10 parts of 70 to 85$ alcohol, and 4 to 6 parts solid potassa. The most of the alcohol is evaporated off, and the cold liquid treated with dilute acid for liberation of the stearic acid, as directed above (d). From non-alkali stearates, acidulating with an acid that does not precipitate the metal, and shaking out with ether, is usually the most expeditious method of separating the stearic acid. from oleic acid stearic acid (with other solid fat acids) is separated by insolubility of lead stearate in ether , as follows. The free fat acids are to be perfectly saponified with potassa or soda ; the neutral solution of the alkali soap, with some alco- hol, is precipitated with lead acetate, and the precipitate washed, dried, and exhausted with ether in repeated portions, when the lead salts of the solid fat acids will be left undissolved, and the lead oleate can be obtained by evaporating the ethereal solution. The details may be governed as follows (KEEMEL '). Of the free fat acids 2 to 3 grams are exactly weighed into a flask of 100 to 150 c.c. capacity, treated with about an equal quantity of dry caustic potash and 10 c.c. of alcohol of 95 per cent, strength, on the water-bath, to complete saponification. The mass is di- luted with a little water, neutralized with acetic acid, using phenol-phthalein as an indicator, the alcohol evaporated off on the water-bath, the residue dissolved in 80 c.c. hot water, and the liquid precipitated with lead acetate solution. When cold the free precipitate is poured upon a filter of 10 cm. (near 4 inches) diameter, and the whole precipitate is washed several times with hot water. The precipitate adhering to the flask is melted on the water-bath, cooled, drained, and dried at a gentle heat, as is also the precipitate in the filter. The contents of the flask are now treated with ether, poured through the same filter, in repeated portions, until the whole precipitate is exhausted of ether-soluble substance. On vaporizing the ether in the filter the lead stearate can be detached, and added to that in the 1 Consult also MUTER: Analyst, 2. 73. STEARIC ACID. 243 flask, where the whole is treated with diluted hydrochloric acid, and exhausted with ether. The filtered ethereal solution is eva- porated in a tared beaker and the residue weighed as stearic acid (including all solid fat acids). For the oleic acid (the total of liquid fat acids) the ethereal solution of lead salt is evaporated to dry ness, and the residue treated with diluted hydrochloric acid and then with ether, as directed for the solid fat acids. Stearic acid (with palmitic acid) is separated from oleic acid by the solvent action of a mixture of alcohol and glacial acetic acid (DAVID, 1878 '). In the proportion of 300 c.c. of alcohol of 95 per cent, strength with 220 c.c. of glacial acetic acid, at 15 C., the oleic acid is just soluble, while the solid fat acids are insoluble. A greater proportion of the acetic acid precipitates oleic acid from its alcoholic solution ; a smaller proportion per- mits the solution of stearic and palmitic acids. A weighed portion of one or two grams of the fat acids under examination, in a flask provided with a tight stopper, is treated with the sol- vent mixture, in twenty-four hours' digestion at about 15 C., with occasional shaking. The mixture is then filtered, washed first with the solvent mixture, then with cold water, gathered into a weighed dish, melted, drained of water, dried in a desic- cator or at 100 C., and weighed as stearic acid. f. Quantitative. Free stearic acid, in absence of other acids, or a total of fat acids to be estimated as stearic acid, may be de- termined in quantity by acidimetry, using phenol-phthalein or litmus as an indicator, and taking the fat acid in alcoholic solu- tion. Each c.c. of normal solution of alkali represents 0.284 gram of stearic acid. Taking 2.84 gram of the material under estimation, each c.c. of decinormal solution of alkali equals 1 per cent, of free stearic acid. Free stearic acid, as obtained by precipitating an alkali stear- ate in aqueous solution with a diluted acid, washing with water, melting to separate water, and drying, may be weighed as C 18 H 36 O 2 . Also the residue of its ethereal solution may be melted, brought to a constant weight, and weighed in the same way. From Oleic acid stearic acid is separated as directed under 0, p. 242 ; in mixture with Palmitic acid stearic acid is estimated by methods given under Fat Acids, Quantitative Determinations of, (5) and (7), p. 250. g. Stearic acid is the " stearin " of the candle industry. 1 Ding. poL Jour., 231, 64; Zeitsch anal. Chem., 18, 622; Benedikt's "Analyse der Fette " (1886), p. 81; Am. Jour. Phar., 55, 356. 244 FATS AND OILS. For determinations of commercial value see under reference last given, especially methods (4) to (8). PALMITIC Aero. C 16 H 32 O 3 == 256 (monobasic). Margaric Acid. 1 Found as a normal glyceride in ordinary vegetable and animal fats. a. As free acid, crystallizable from alcoholic solution in fine needles, sometimes grouped in sheaves, or congealing from a melted mass in partly crystalline forms of pearly lustre. Melts* at 62 C., at which temperature the liquid has the sp. gr. 0.8527. At about 350 C. it distils with partial decomposition. It leaves a permanent oil stain on paper. Under the reduced pressure of 100 millimeters it distils at 268.5 C. The glyceride, Palinitin, C 3 H 5 (C 16 H 31 Oo) 3 , is crystallizable, in pearly lustrous forms. It melts at temperatures from 50.5 to 66.5 C., according to its previous exposure to heat. Strongly heated it carbonizes abundantly. &. Palmitic acid, as well as palmitin, is odorless and of a bland, oily taste. c. Palmitic acid is insoluble in water, and but sparingly and slowly soluble in cold alcohol, requiring 10.7 parts of absolute alcohol for solution, but hot alcohol dissolves it more freely, yielding crystals as the solution cools. It dissolves freely in ether. The alcoholic solution has an acid reaction. The normal glyceride, palmitin, is but slightly soluble in cold alcohol, moderately soluble in hot alcohol, and soluble in ether, chloroform, benzene, petroleum benzin, and in carbon disulphide. Alkali palmitates (soaps of palmitin) are soluble in water, with tendency to turbidity from slight decomposition, increased by dilution ; more permanently soluble in alcohol, scarcely at all soluble in ether. Non-alkali metallic palmitates are insoluble in water or ether. Lead palmitate is insoluble in alcohol. Barium and calcium palmitates are slightly soluble in alcohol. d. In qualitative reactions palmitic acid does not sensibly differ from stearic acid. Its distinction from stearic acid re- quires quantitative work. e. Separations of palmitic acid are made with stearic acid, or, if this be absent, by the same methods given for stearic acid sep- aration (Stearic Acid, e). 1 This synonym is used by some French chemists. VARIOUS ACIDS. 245 f. Quantitative determinations of palmitic acid alone are done by the methods given for Stearic acid. When in mixture with stearic acid, methods of indirect determination are resorted to, as given under Fatty Acids, Quantitative Estimation of, (5) and (7). g. Palmitic acid enters into the stearic acid known in com- merce and in candle manufacture as " Stearin," and into " Oleo- margarin." See under these heads (Index). MYEISTIC ACID, C 14 H 28 O 2 . The fourteen-carbon member of the CnHjjnOg series of fat acids. Closely resembles Laurie acid. A solid, melting at 53.8 C., at which temperature the liquid has sp. gr. 0.8622. It is insoluble in water, sparingly soluble in cold alcohol and in ether. LAUEIC ACID. The C 1Q H 24 O 2 acid obtained from fats is a solid, fusible at 48.6 C., and of sp. gr. 0.883 at 20 C. It crys- tallizes from alcohol in needles. It does not vaporize, alone and tinder ordinary pressure, without being mostly decomposed, but distils with steam. In large quantities of boiling water sensible traces are dissolved. CAPEIC ACID, C 10 H 20 O 2 . The capric acid obtained from fats is solid at ordinary temperatures, forming small tabular crystals, melting at 31.3 to 31.4 C., boiling at 268-270 C., and of sp. gr. 0.93 at 37 C. It is soluble in about 1000 parts of water ; its calcium salt, very slightly soluble in water. CAPEYLIC ACID, C 8 II 16 O 2 . The caprylic acid obtained from fats congeals at 12 C. to a crystalline mass, melting at 16.5 C. Boils at 236-237 C. At 20 C. has sp. gr. 0.914. Of a sweet taste. Soluble in 400 parts of water. The calcium salt dissolves in 200 parts of water. CAPEOIC ACID, C 6 II 12 O 2 . Isobutyl-acetic acid. Found as a glyceride in fats. Congeals at 18 C., boils at 199.7 C., is scarcely ^ at all soluble in water. At 20 C., sp. gr. 0.925. Of a sweetish taste. The calcium salt dissolves in 37 parts of water. FATTY SEEIES OF ACIDS, C n H 2n _ 2 O 2 . Oleic acid series. The following members of this and other immediately related series are found in fats : 246 FATS AND OILS. Oleic Acid ...... . C 18 H 34 = C 17 H 33 .CO 3 H. SERIES C n H 2n _ 2 O 3 : Ricinoleic Acid. . . C 18 H 34 O 3 . SERIES Cnll^.^g : Linoleic Acid.... C 16 H 28 O 2 = C 15 H 27 .C0 2 H. OLEIC ACID, C 18 H 34 O 2 = 282. The members of the fatty series C n H 2n _ 2 O 2 contain two atoms of hydrogen less than cor- responding members of the fatty series Cnli^C^ , and by action of reducing agents the former are in general convertible into the latter. The normal glyceride of oleic acid, olein, C 3 H 5 (C 18 H 33 O 2 ) 3 = 884, is found in greater or smaller proportion in most vegeta- ble and animal fats, and in non-drying oils. a. Pure oleic acid is a colorless oil, congealing at 4 C. ? melt- ing at 14 C., at which temperature the liquid has sp.gr. 0.898. Under ordinary pressure it does not distil alone undecomposed, but is carried over with superheated steam at about 250 C. The triglyceride, olein, is a liquid which congeals at low atmos- pheric temperatures, and in vacuum distils slowly without de- composition. b. Oleic acid is a bland, tasteless, when pure nearly or quite odorless liquid, indifferent in physiological action. c. Oleic acid is insoluble in water, soluble in alcohol not very dilute, and separated from the solid fat acids by its greater solubility in a mixture of acetic acid and alcohol. It is soluble in chloroform, benzol, petroleum benzin, and in the fixed oils. The triglyceride, olein, is somewhat soluble in absolute alcohol, in fact much more so than are stearin and palmitin, but is inso- luble in dilute alcohol. Pure oleic acid is neutral to litmus-pa- per, but it gives the acid reaction with phenol-phthalein, decolor- ing the alkaline mixture of this indicator at formation of normal alkali oleates. By exposure to air for a short time oleic acid suffers such changes as impart to it an acid reaction, and it soon becomes rancid and of a yellowish color. The alkali oleates are soluble in water, the solution becoming somewhat turbid by de- composition when diluted with water, though bearing dilution better than stearate or palmitate. The oleates of non-alkali me- tals are insoluble in water, but more or less freely soluble in al- cohol, and in some instances (including the lead salt) soluble in OLE 1C ACID. 247 ether. The silver oleate is not soluble in ether. The alkali oleates are precipitated from their aqueous solutions by sodium chloride, and to some extent by excess of alkalies. Sodium oleate is soluble in 10 parts of water at 12 C., in 20.6 parts of alcohol of 0.821 applied at 13 C., or in 100 parts of boiling ether. From absolute alcohol it is crystallizable. Potassium oleate, in ordi- nary moist condition, is soft or gelatinous, and is much more so- luble in water or alcohol or ether than is the sodium salt. Ba- rium oleate is insoluble in water, and but very slightly soluble in alcohol. Magnesium-alkali oleate possesses a capacity of slight and transient foaming in aqueous solution, perhaps due to a tardy precipitation, and distinguishing it from calcium oleate in the soap test of hard waters. d. Oleic acid is characterized by its consistence as a liquid non-volatile fatty body, and by the action of oxidizing agents upon it. Nitric acid with metallic copper, fuming nitric acid, mercury nitrates, or other form of nitrous acid, in digestion with oleic acid, produces its isomer elaidic acid, as in digestion with olein it forms elaidin, glyceride of elaidic acid. Elaidic acid is a solid, and its formation is indicated first by a soft waxy, and finally by a resinous consistence. Elaidic acid dissolves in alco- hol, from which it crystallizes in tabular forms, melting at 45 C. Bromine acts readily, and iodine or chlorine quite easily, on oleic acid, producing dibrom-stearic acid, an addition product of oleic acid, C 17 H 33 Br 2 . CO 2 H, on the type of the C n H 2n Oo series. To 7 parts of the oleic acid 4 parts of bromine are added, drop by drop, stirring after each addition. The product is yellowish, of an oily consistence. To form the di-iod-stearic acid, molecular proportions of the oleic acid and of the iodine are taken, each being dissolved in alcohol, when the iodine solution is gradually added, this being the reaction of Hubl's estimation, giving the iodine number. e. Separations. In manufacture oleic acid is separated from the solid fat acids by filtration under pressure at low tempera- tures above the congealing point of the oleic acid. For methods of separation from the solid fat acids by sol- vents, etc., see Stearic acid, e. Directions for separation (pro- duction) from olein by saponification are essentially those given under Hehner's method. f. Quantitative. Oleic acid is estimated volumetrically by standard solution of potassa or soda, using phenol-phthalein as an indicator. Each c.c. of normal solution of alkali represents 248 FATS AND OILS. 282 gram of oleic acid. Taking 2.82 grams of material, each c.c. of decinormal solution of alkali counts 1 per cent, of oleic acid. Taking 14.1 gram of material, c.c. of normal solution of alkali X 2 == per cent, oleic acid. Gravimetric estimation of free oleic acid is effected by adding to the free acid, in a layer over an aqueous liquid, a weighed portion of recently fused beeswax or paraffin, heating to melt the solid, and when cold detaching the oily mass, drying in a tared capsule, and weighing, when the weight of the wax is subtracted. Also free oleic acid, dissolved in ether, may be freed from the latter by evaporation in a tared beaker or flask, avoiding oxidation by exposure to the air, and the weight of the oleic acid may be obtained. g. The U. S. Ph. gives the following specifications for oleic acid : " At 14 C. (57 F.) it becomes semi-solid, and remains so until cooled to 4 C. (39 F.), at which temperature it becomes a whitish mass of crystals. At a gentle heat the acid is completely saponified by carbonate of potassium. If the resulting soap be dissolved in water and exactly neutralized with acetic acid, the liquid will form a white precipitate with test solution of acetate of lead. This precipitate, after being twice washed with boiling water [drained and dried], should be almost entirely soluble in ether (absence of more than traces of palmitic and stearic acids). Equal volumes of the acid and alcohol, heated to 25 C. (77 F.), should give a clear solution, without separating oily drops upon the surface (fixed oils)." The specifications of the Br. Ph. are as follows : " A straw-colored liquid, nearly odorless and tasteless, and with not more than a very faint acid reaction. Unduly ex- posed to air it becomes brown and decidedly acid. Specific gravity 0.860 to 0.899. At 40 to 41 F. (4.5 to 5.0 C.) it be- comes semi-solid, melting again at 56 to 60 F. (13.3 to 15.5 C.) It should be completely saponified when warmed with carbonate of potassium, and an aqueous solution of this salt neutralized by acetic acid and treated with acetate of lead should yield a preci- pitate which, after washing with boiling water, is almost entirely soluble in ether." EICINOLEIC ACID, C 18 H 34 O3=298. The fat acid constituting, in its normal glyceride, the principal part of castor oil. In com- position an oxy-oleic acid of the proportions C n H2n_ 2 O 3 . a. A thick oil, of sp. gr. 0.940 at 15 C., congealing at 6 to 10 C., and does not vaporize un decomposed. The lead salt melts at 100 C. b. The glyceride, as obtained in castor oil, is odorless, with a LINOLEIC ACID.HYPOGAIC ACID. 249 mild taste and slightly acrid after-taste, and exerting a cathartic effect. c. Ricinoleic acid is insoluble in water ; soluble in all pro- portions in alcohol and in ether. The lead salt is soluble in ether. Castor oil is soluble, at 15 C., in 2 parts of 90$ alcohol or 4 parts of 84$ alcohol. It is but slightly soluble in petroleum benzin, paraffin oil, or kerosene, though it takes up about its own volume of petroleum benzin. d. Ricinoleic ,acid is but very slightly oxidized by exposure to air. Treated with bromine i,t takes two atoms of bromine in the molecule of the acid, forming C 18 H 34 Br 2 O 3 , corresponding to the reaction of oleic acid. In the elaidin reaction, by action of nitric acid, ricinelaidic acid is formed, isomeric with ricinoleic acid, and fusible at 50 C. LINOLEIC ACID, Ci 6 H 28 O 2 =252. The only well-known mem- ber of the series of fat acids C n H 2n _ 4 O 2 . In the normal glyce- ride forms the principal portion of linseed oil, representative of the drying oils. In oxidation, or " drying," it forms addition products, such as C 16 Ho 8 Br 4 O 2 , corresponding in composition to C n H 2n O 2 . Therefore in reaction with oxidizing agents it has twice the saturating power per molecule possessed by oleic acid. a. Linoleic acid is a permanent liquid of a pale yellow color and sp. gr. 0.9206 at 14 C. The glyceride, as obtained in linseed oil, congeals at 16 C. (GussEKOw), 27 C. (AKCHBUTT and AL- LEN), and melts at 16 to 20 C. (GLASSNER). b. Linseed oil has a characteristic odor and taste. c. Insoluble in water, readily soluble in alcohol and in ether. Of u feeble acid reaction, and capable of neutralizing alkalies to phenol-phthalein and other indicators. The barium and calcium salts dissolve in hot alcohol. Ether dissolves the linoleates of lead, zinc, copper, and calcium. d. Linoleic acid is easily oxidized by exposure to the air. In thin layers in a few days it forms a solid, resin-like body known as Oxylinoleic acid, and afterward takes on the character of a neutral body, insoluble in ether, and sometimes termed Linoxyn. HYPOGAIC ACID, C 16 H 30 O 2 . A white solid, crystallizing in needles, melting at 33 C., not readily vaporizing in ordinary conditions without decomposition. By exposure to air soon be- 250 FATS AND OILS. comes rancid, acquiring a brown color, and giving origin to vola- tile acids. In the elaidin test it is changed to its isomer gaidic acid, fusible at 39 C. PHYSETOLEIC ACID, isomeric with Hypogaic acid, C 16 H 30 O 2 , melts at 30 C., and is not affected by the elaidin test. FAT ACIDS, QUANTITATIVE DETERMINATIONS OF. Besides the methods of volumetric and gravimetric estimation of separate fat acids, or of total fat acids in terms of stearic acid, by equivalence of saturation, certain special determinations have been made, upon stated authorities, as indices of composition, related to as- certained limits, representing values for given uses. (1) The number of parts of insoluble fat acids obtainable from 100 parts of clear neutral fat (HEHNER'S number). (2) The number of c.c. of decinormal alkali solution saturated by the volatile fat acids distilled from 2. 5 grams of the fat (REICHERT'S number). (3) The number of milligrams (thousandths) of potassium hydrate saturated by saponifying 1 gram (one part) of the fat (KOTTSTORFER'S number). The saponifi cation number. The methods above named have been devised to distinguish butter from its substitutes. (4) The percentage of iodine which the oleins of the fat will take into combination by a defined procedure (HUBL'S iodine numberX (5) The molecular weight, as obtained by acidimetry. (The quantity saturated by 1000 c.c. normal solution of alkali.) For mixtures of palmitic and stearic acids. (6) The specific gravity, as a limited indication. (7) The melting and congealing points. (8) Calculation of constituent Fat Acids and Neutral Fats. (1) Estimation of tfie insoluble fat acids : HEHNER'S Method. 1 To obtain the butter fat from butter melt a portion on the water-bath, leave the liquid to settle while melted, decant the clear liquid only upon a dried filter in a hot funnel, and take the filtrate. It must be perfectly clear and not lose weight on '0. HEHNER, 1877: Zeitsch. anal. Chem., 16, 145. HEHNER and ANGELL, 1877: "Butter, its Analysis and Adulterations." London, second edition. MU- TER, 1876: Analyst, I, 7. DUPRE, 1876: Phar. Jour. Trans., [3], 7, 131. JONES, 1877: Analyst, 2, 20. FLEISCHMANN and VIETH. 1878: Zeitsch. anal. Chem., 17, 287. Manipulation at the Depart, of Agriculture, Washington, REPORT DEPT. AGR., 1884, Prof. WILEY, Chemist, p. 60. Further, see citations under Butter Pat. DE TERM IN A TION OF FAT A CIDS. 2 5 1 the water-bath. Keep in a light beaker, and take out for an analysis from 3 to 4 grams of the clear fat into an evaporating- dish of about 5 inches (13 centimeters) diameter, using a glass rod to be left in the evaporating-dish, and weighing the beaker before and after the removal to obtain the exact weight of fat taken. Add 50 c.c. of alcohol of about 85$, and. 1 to 2 grams of pure (alcoholic) potassium hydrate, and warm and stir the mix- ture until a clear solution is obtained. After five minutes' fur- ther warm digestion add a few drops of distilled water, and if a turbidity is caused continue the digestion until the addition of water produces no turbidity. If this satisfactory saponih'cation is not attained the failure is probably due to a too great dilution of the potash with alcohol, and the operation is to be commenced anew. If the alcohol be too strong, saponification is prevented. The clear saponified solution is now evaporated over the water- bath to a syrupy consistence, and the residue dissolved in 100 to 150 c.c. of water. To the clear liquid add diluted sulphuric or hydrochloric acid to a strongly acid reaction. The creamy sepa- rate of the insoluble fat acids rises for the most part to the sur- face. Heat of a bath of water below boiling is now applied to melt the precipitate, and continued for half an hour and until the layer of fat acids above is perfectly clear and the aqueous liquid below is nearly clear. Meantime a filter of 4 to 5 inches (10 to 13 centimeters) diameter, of the closest filter-paper (Swe- dish), is dried in the water-box. The filter should be close enough to transmit hot water only by drops. A small beaker is weighed, also a filter weighing-tube and this tube with the filter, to give the weight of the latter. The weighed filter is placed in a funnel wetted and half -filled with water. The watery liquid and melted fat are then poured from the dish upon the filter, which is not to be at any time more than two- thirds filled ; the dish and rod are rinsed with boiling water, and washing with boiling water is to be continued until the washings cease to redden litmus-paper, about J liter (TOO to 1000 c.c.) of filtrate being usually obtained. 1 (The rins- ing of the dish seldom leaves behind more than a milligram of fat, but this is saved by taking it up with a little ether and the solution added to the fat acids in the beaker afterward.) The 1 FLETSCHMANN and VIETH (1878) advise care to avoid imperfect solution of lauric acid (abounding in cocoanut oil), washing until 5 c.c. of the filtrate ceases to change the color of one drop of litmus tincture added thereto. E. WALLER and his associates (1886: Report N. Y. State Dairy Commissioner) wash with six or seven instalments of hot water (about 100 c.c. each), rinsing off between each with about 25 c.c. of cold water. 252 FATS AND OILS. drained funnel is set well down in a beaker of cold water, and when the fat acids have hardened the filter is detached, drained, and placed in the weighed beaker. 1 This is heated on the water- bath to a (nearly) constant weight. Weigh after about two hours' drying, and after a half-hour's further drying weigh again. If any drops of water collect below the fat add a drop or two of alcohol. In this drying there may be slight increase by oxida- tion of oleic acid, and slight decrease by vaporization of fat acids. If the filter have been close enough no fat globules will have passed, and none will be revealed by microscopic examination of the filtrate. The weight of the beaker and contents, minus the weights or tares of the beaker and the filter, leaves the weight of the fat acids, which is to be divided by the weight of purified fat taken, to obtain the proportion ( X 100 = $) of insoluble fat acids. If 87.5 be accepted .as the full per cent, of insoluble fat acids in butter, and 95.5 as the per cent, of insoluble fat acids in " meat fats," then 95 5 87. 5 = 8, and 8 : found percentage minus 87.5 :: 100 : a? = per cent, of " meat fats" present in the clear fat examined. For the calculation of percentage in entire but- ter see under Butter, Interpretation of Results. DALICAN modifies Hehner's process by taking 10 grams of the clear butter fat in a flask of 250 to 300 c.c. capacity, and adding 80 c.c. of 85$ alcohol, and 6 grams of sodium hydrate dissolved in 6 to 8 c.c. water, when by 30 to 40 minutes of warming and stirring the saponification is ended. The alcohol is evaporated off, 150 c.c. of water added, and 25 c.c. of hydrochloric acid diluted with four parts of water are added in small portions at a time, rotating the flask after each addition. The mixture is now heated over the water-bath for 25 to 30 minutes, until the fat layer separates with perfect clearness and white points are no longer seen. The flask is set aside for 30 minutes, and then cooled with water. After two hours the fat layer is broken with a glass rod, the water poured on a wetted filter, about 250 c.c. of boiling water added in two portions to the flask, shaking after adding the first portion. The flask is then set aside 40 minutes, cooled by immersion in water, and the water decanted on the filter as before. This washing by decantation, as above, is repeated until the decanted liquid ceases to redden litmus- paper on 20 minutes' contact, 8 or 10 washings being necessary. 1 "The insoluble acids are brought into a tared dish, any in the filter or flask being dissolved in ether, dried at 100 C. with stirring with absolute alco- hol to remove water, and weighed." H. W. WILEY, Chemist Dept. Agricul- ture, Washington, Report of 1884. DE TERMINA TION OF FAT A CIDS. 2 5 3 The insoluble fat acids are finally gathered in a tared porcelain capsule or evaporating- dish, the flask being washed with hot water, and all washings passed through the filter. The filter must be kept wet, and the slight portion of fat acids upon it can easily be detached. The drying is done at 100 to 110 C., at first for an hour, and a second weight is taken in 15 or 20 minutes. For results with vegetable and animal fats see tables following; also Butter Fat. (2) REICHERT'S method 1 embraces the estimation of the vola- tile fat acids, separated by distillation. " Reichert's number " is the number of c c. of decinormal solution of alkali taken to neu- tralize the distilled fat acids from 2.5 grams of fat. Sometimes, however, results are specified for 5 grams or for 10 grams of the fat. Of the clear filtered fat 2.5 grams are taken in 'an Erlen- meyer's flask of about 150 c.c. capacity, with 1 gram potassium hydrate and 20 c.c. of 80$ alcohol, and the whole digested on the water-bath, with shaking by circular motion until saponification is complete and no more pasty masses remain. Now 50 c.c. of water are added, then 20 c.c. of diluted (1 to 10) sulphuric acid, and the mixture distilled. To avoid bumping a slight stream of air may be introduced. The distillate is received in a 50 c.c. flask, into which is set a funnel carrying a wetted filter, receiving the distillate, so that any insoluble fat acid otherwise possible in the distillate may be rejected. The first 10 or 20 c.c. of distillate are returned to the flask ; then 50 c.c. are distilled. The volume of the distilled liquid should always bear the same proportion to that of the distillate. This distillate is charged with a few drops of phenol-phthalein solution, and titrated with the decinormal solution of alkali, until the color of the alkali reaction becomes constant. The required number of c.c. (2.5 grams of fat having been taken) is Reichert's number. MEISSL'S modification of Reichert's process 3 undertakes a more complete distillation of the volatile fat acids, and the use of weaker alcohol in saponification to avoid etherizing the acids, as follows : 5 grams of the clear filtered fat are treated in a flask of 200 c.c. capacity with 2 grams of solid potash and 50 c c. of 70$ alcohol (free from acidity or aldehyde), over the water-bath, . J E. REICHERT, 1879: Zeitsch. anal. Chem., 18, 68; Jour. Chem. Soc., 36, 406. ALLEN, 1885: Analyst, 10, 103. R. W. MOORE, 1885: Jour. Am. Chem. Soc., 7, 188; Analyst, 10, 224; Am. Chem. Jour., 6, 417: Chem. News. 50, 268; Jour. Chem. Soc., 48, 300, 1014. E. REICHARDT, 1884: Zeitsch. anal. Chem,., 23, 565; Jour. Chem. Soc., 46, 1219. 2 E. MEISSL, 1880: Bied. Cent., 1880, 471; Jour. Chem. Soc., 38, 828. 254 FATS AND OILS. with stirring, until saponified perfectly. The alcohol is evapo- rated, and the thick soap is dissolved in 100 c.c. of water, pre- cipitated with 4 c.c. of diluted (1 to 10) sulphuric acid, and, after the addition of a few pieces of pumice-stone, distilled with use of a Liebig's condenser. Of distillate 110 c.c. are received in a flask marked at this capacity, this quantity being obtained in about an hour. The distillate is filtered into a flask marked at 100 c.c., and this volume of the filtrate is titrated, after addition of phe- nol-phthalein or litmus, with decinormal solution of alkali. The number of c.c. required is increased by its one-tenth, and for Reichert's number (on 2.5 of fat) the result of this operation is divided by two. To exclude all interferences a control analysis without fat may be conducted parallel with the assay. The Reichert's numbers of fats are given under Butter Fat. (3) Kottstorfer* s method. 1 Determination of the number of milligrams of potassium hydroxide necessary to saponify 1 gram of the fat the " Yerseif ungszahl," or saponification number. The operation requires (1) solution of hydrochloric acid, and (2) alcoholic solution of potassa, both of about half-normal strength. Also (3) a decinormal solution of alkali, exactly standardized. The potassa solution is made of caustic potassa purified by alco- hol, dissolved in the least sufficient proportion of water and di- luted to standard with alcohol free from fusel oil. It may be prepared by filtration through animal charcoal. If the alcohol be pure a solution of the designated strength will not become darker than yellowish. Of the purified fat 1 to 2 grams are digested in a covered beaker or flask of about 70 c.c. capacity, with just 25 c.c. of the alcoholic potassa solution, on the water-bath, at near boiling of the liquid, stirring with a glass rod, to perfect saponification. It is believed to be necessary to take precautions against the escape of ethyl butyrate. One c.c. of phenol-phthalein solution is added, and the liquid titrated with the standard hydrochloric acid to the neutral point. Another 25 c.c. of the potash solution alone is titrated with the hydrochloric acid solution, and the latter titrated with the deci- normal alkali. The number of c.c. of the standard alkali taken for the 1 gram of fat, minus the hydrochloric acid in the titra- tion, converted, according to the comparisons made, into milli- 1 J. KOTTSTORFER, 1879: ZeitscJi. anal. Chem., 18, 199, 431; Jour. Chem. Soc., 36, 983, 1069; Analyst, 4, 106. MOORE, 1885: Jour. Amer. Chem. Soc., 7, 188; Analyst, 10, 224; Chem. News, 50, 268; Am. Chem. Jour., 6, 417; Jour. Chem. tioc., 48, 300, 1014. DETERMINATION OF FAT ACIDS. 255 grams of potassium hydroxide, gives the saponification number sought. The details are carried out upon fats of butter and its substitutes by Prof. WILEY (1884) as follows: The dried and filtered butter-fat is weighed in a small beaker with a 2 c.c. pipette. Five stout hali'-pint beer-bottles of clear glass, with rubber stoppers secured by a spring, are provided. Three portions, of 2 c.c. each, of the fat melted at about 35 C. are introduced severally into three of the bottles, weighing the beaker and pipette after each addition, and noting the exact weight of fat taken in each of the three bottles. Of the alco- holic potash solution just 25 c.c. is now run into each of the five bottles. The bottles are stoppered and placed on the same steam or water-bath, and shaken every five minutes until the fat is sa- ponified. Then the bottles are cooled, opened, and 1 c.c. phenol- phthalein solution added to each. Each of the five portions is now titrated with the half-normal hydrochloric acid to the neu- tral point. The two blanks give an average for the strength of the alcoholic potash, and the three portions of fats give an ave- rage for the amount of potash neutralized in saponification. That is, the mean number of c.c. of hydrochloric acid for one of the two blank portions, minus the mean of c.c. of the same acid calculated for 1 gram of fat in one of the three fat-portions, equals the no. c.c. of the hydrochloric acid neutralized by the total fat acids in 1 gram of the fat. This last no. of c.c. of hydrochloric acid is to be titrated with the exactly standardized decinormal al- kali, and the required no. of c.c. of the latter is multiplied by 5.6 to obtain the milligrams KOH for the fat acids of 1 ram of fat. Kottstorfer's Number, the milligrams of KOH to saponify 1 gram of fat, is to be distinguished from the " Saturation- Equi- valent " of fats. The latter term is defined as the number of milligrams of fat saponifiable by 1 c.c. of normal alkali solution. For the triglycerides it is the third of their molecular weight ; or it is the hydrogen-equivalent number of the fat. 56000 -T- Kottstorfer's number = " saturation-equivalent "; and 56000 -r- u saturation equivalent " = Kottstorfer's number. PEEKINS' combines the methods of Hehner, Keichert, and Kottstorfer, as follows : Of the clear fat 1 to 2 grams is saponified ; an excess of a cold-saturated solution of oxalic acid is added, and the fat acids separated in the cold, and then washed on the filter with hot water. The filtrate is made up to 200 c.c., and distilled 1 F. P. PERKINS, 1878: Analyst, 3, 241; Zeitsch. anal. Chem., 19, 237. 2 5 6 FATS AND OILS. to give 100 c.c. of distillate (according to Reichert), this being titrated with alkali and the result stated in milligrams of potas- sium hydroxide to saturate the volatile acids from 1 gram of pu- rified fat. The insoluble fat acids, as washed, are dissolved in 100 c.c. of hot alcohol, and this solution, or an aliquot part of it, titrated with decinormal alkali, calculating the result into milli- grams of potassium hydroxide for the insoluble fat acids of 1 gram of fat. The former number plus the latter number gives the milligrams of potassium hydroxide to saturate all the fat acids of the 1 gram of purified fat. Percentages of Insoluble Fat Acids. Hehner^s Numbers. Olein Palmitin Stearin Butyrin Oleomargarin. . Cotton- seed oil Cotton stearin . Lard . . Olive oil Peanut oil .... Palm oil Sesame oil. . . . Theobroma oil Seal oil Rape oil Cocoanut oil . . Butter fat, lowest . . highest.. " common mum . maxi- 95.75 95.28 95.73 87.41 95.56 j 95.75 ( 94.29 95.5 96.15 95.43 95.09 95.00 95.6 95.48 94.59 90.68 95.10 86.43 80.78 86.6 88.5 87.5 Theoretical quantity. HEHNER'S determinations. (BENSEMANN). (E. WALLER, 1886). (MUTER). (WEST-KNIGHTS). u (E. WALLER). a (HEHNER). (E. WALLER). (BENSEMANN). (E. WALLER). (BENSEMANN). (MOORE). E. WALLER). HEHNER and ANGELL). Butter fat, lowest of nine . . . " highest " ... From 26 genuine ( lowest. American butters, j highest From 25 butters, ) lowest. Pennsylvania .... j highest }oiq I WILEY, Washington, 1884. 86.40 ) E. WALLER, 90.24 | New York, 1886. 86.7 87.7 C. B. COCHRAN, 1886. DETERMINATION OF FAT ACIDS. 257 KOTTSTOKFER. a Sapotiification Coefficients : Kottstorfer* s Numbers (p. 254). (Milligrams of KOH neutralized in saponifying 1 gram of Fat.) Stearin 188. 8 By calculation. Olein 190.0 " Palmitin 208.0 Butyrin 557.3 Beef Tallow 196.5 u " commercial.... 196.8 Mutton Tallow 197.0 Lard 195.7 Olive oil , 191.8 Eape " 178.7 ( mean. . . 227.0 Butter Fat \ lowest. . 221.5 ( highest. 233.0 Fat of Rancid Butter about 1.5 lower than when fresh. " Cocoanut oil 250.3 (MooKE, 1884). " " washed 246.2 " " " 49.3^, Oleomar- garin 50.70 220.0 " Cocoanut oil 70.2$, Oleomar- garin 29.80 234.9 " Almond oil, sweet 194.7-196.1 (VALENTA, 1883). Apricot oil 192.9 194.5 181.0 " . 176-178 (ALLEN, 1884). Cotton-seed oil 195 (VALENTA). Lard oil 191-196 (ALLEN). Bitter Almond, fixed oil. Castor oil. 191-196 ( 189-195 \ 195.2 (MOORE). ( 191.7 (YALENTA). Olive oil \ 191-196 (ALLEN). ( 185.2 (MOORE). j 191.3 (VALENTA). \ 196.6 (MOORE). Sesame oil 190.0 (VALENTA). Sperm oil 130.0-134.4 (ALLEN). Theobroma oil 199. 8 (MOORE). Train oil 190-191 (ALLEN). Messrs. WALLER -and MARTIN (1886 : Report of the Dairy Linseed oil Peanut oil , 258 FATS AND OILS. Commissioner of the State of New York) obtained, from 25 genu- ine American butters, Kottstorfer's numbers from 220.6 to 230.1 (extremes) ; a rancid butter, 223.0 ; the same deodorized, 219.45 ; and from the insoluble fat acids of a butter, 214.25. From oleo- margarin 188.65; another, 191.6. From mutton suet, 203.25 ; beef suet, 199.2; lard, 195.85. From cottonseed oil, 162.0 to 193.05 ; average of five, 183.47. (4) Determination of Fat Acids ly their capacity of combi- nation with iodine. The fat acids, whether free or in their glycerides, form combinations with iodine, bromine, or chlorine. One molecule of oleic acid or ricinoleic acid takes two atoms of iodine ; one molecule of linoleic acid, four atoms of iodine ; ad- dition products being formed. The directions of HUBL 1 for finding the percentage of iodine taken into combination (the iodine number) are as follows, com- mencing with preparation of the needful reagents : (1) Iodine solution. Of iodine 25 grams are dissolved in 500 c.c. of alcohol (free from fusel oil) ; of mercuric chloride 30 grams are dissolved in 500 c.c. of the alcohol, and this solution filtered if necessary; when the two solutions are united, and, after 6 to 12 hours 1 standing, titrated with the standardized thiosulphate solution, and the standard noted. (2) Thiosulphate solution. A solution of about 24 grams of sodium thiosulphate in the liter is made, and its iodine value accurately determined with a weighed quan- tity of freshly sublimed iodine. About 0.2 gram of resublimed iodine is placed in a small glass tube closed at one end and pro- vided with a similar tube enough larger to serve as a cover, both tubes being previously dried and weighed. The iodine is heated in the inner tube, on a sand-bath, until it melts, then covered with the outer tube, cooled in a desiccator, and weighed. The cover is now removed and both tubes are placed in a stoppered flask con- taining 1 gram of potassium iodide (neutral and free from iodine) dissolved in 10 c.c. of water. When the iodine has dissolved, the solution of thiosulphate of sodium is added from a burette until the iodine color is reduced to a faint yellow, a little starch solu- tion is added, and the titration completed to the extinction of the blue color. The iodine value of the thiosulphate solution is now written. (3) Chloroform. The purity of chloroform is as- sured for this assay by digesting 10 c.c. of it with 10 c.c. of the iodine solution at ordinary temperature for two or three hours' and titrating to the extinction of the iodine with the thiosul- 1 1884: Ding. pol. Jour., 253, 281; Jour. Chem. Soc., 46, 1435; Am. Chem. Jour., 6, 285. DETERMINATION OF FAT ACIDS. 259 phate solution, the stated quantity of which should be consumed. (4) Potassium iodide solution. One part of pure iodide of potas- sium in 10 parts of water. It should be neutral in reaction, and should not contain any free iodine. For the assay, 0.2 to 0.3 gram of a drying oil, or 0.3 to 0.4 gram of a non-drying oil, or 0.8 to 1.0 gram of a solid fat, is taken in a close-stoppered Hask of about 200 c.c., and 10 c.c. of the chloroform are added for solution. Of the iodine solution 20 c.c. are added in exact measure, and, if the mixture does not become clear after shaking, a little more chloroform is added. The quantity of iodine should be sufficient to leave a dark brown color after one and a half or two hours' standing, the time to be taken for the reaction. In titrating the remaining excess of the iodine, 10 to 15 c.c. of the potassium iodide solution and, after shaking, 150 c.c. of water are added, when the thiosulphate solu- tion is added, with shaking, until the color of both the aqueous layer and the chloroform layer is reduced to a pale yellow, when starch solution is introduced and the extinction of the iodiu 3 completed. For close results the iodine and thiosulphate solu- tions should be standardized just before or after the assay. The number of parts of iodine taken by 100 parts of the fat is known as its iodine number. Using a sufficient excess of iodine in the reaction, quite constant results are promised. Iodine Numbers. c\-\ -A n TT r* S 90.07 By calculation. Okie acid, C,H,A | 89 g to 90 g ^ experiment Kicinoleic acid, C 18 H 34 O 3 . . . 85.24 By calculation. Linoleic acid, C 16 H 28 O 2 201.59 " u Linseed oil 158 (HtJBL). 155.2 (MooKE). 1 Hempseed oil 143 " Walnut oil 143 " Poppy oil 136 " 134 " Cotton seed oil 106 108.7 " Sesame oil 106 102.7 " Eape and Eubsen oils 100 " 103.6 " Olive oil 82.8 83.0 " Olive-seed oil 81.8 Castor oil 84.4 " Almond oil (sweet) 98.4 " 98.1 " Mustard oil (fixed) 96.0 1 R. W. MOORE, 1885: Am. Chem. Jour., 6, 416. ,- 260 FATS AND OILS. Bone oil. . ^ 68.0 (HUBL). Cod-liver oil 123 to 141 (KKEMEL). Lard 59.0 (HtiBL). 61.9 (MOORE). Oleomargarin 55.3 " 50.0 " Palm oil 55.5 " 50.3 " Tallow 40.0 " Wool fat 36.0 Cacao butter (theobroma oil) 34.0 " Mace oil (nutmeg butter). . 31.0 " Butter fat 31.0 " 32.8 to 38.0 " " " very old 19.5 " Cocoanut oil 8.9 " 8.9 " Japan wax 4.2 " Fat acids of bone oil 57.4 (MORAWSKI and DEMSKI). Fat acids of tallow of beef. 25.9 to 32.8 " " Fat acids of cocoanut oil. . 8.4 to 8.8 " " Fat acids of linseed oil 155.2 to 155.9 " " Fat acids of olive oil 86.1 " " Fat acids of cotton seed oil. 110.9 to 111.4 " " Fat acids of castor oil 86.6 to 88.3 " Mineral oils (petroleum, shale) Seldom above 14 VALENTA (1884). Eosin oils 43 to 48 " Messrs. WALLER and MARTIN (1886 : Eeport of N. Y. State Dairy Commissioner) found Htibl's numbers as follows : Ayrshire butter 34.7 Jersey " sweet cream 36.7 " " sour cream 30.5 Native " 30.5 Devon " sour cream 37.0 Eancid " 40.5 Oleomargarin 50.9 to 54.9 Cotton-seed oil 108.4 Linseed oil (average of 2) 165.4 Cocoanut oil (average of 2) 7.8 Commercial Stearin.. 1.7 DETERMINATION OF FAT ACIDS. 261 (5) Estimation of Stearic and Palmitic Acids separately in mixtures of the two, by the mean molecular weight of the mix- ture. The molecular weights of stearic and oleic acids, 284 and 282, do not differ from each other enough to give any value to this method applied to mixtures of these two acids. It is appli- cable to tallows from which the olein has been removed by pres- sure. About 50 grams are treated for the separation of the fat acids, by digesting with 40 c.c. potassium hydrate solution of- sp. gr. 1.4, and 40 c.c. of alcohol. After boiling to full saponiiication, one liter of water is added and the liquid boil- ed about three-fourths of an hour to remove the alcohol, diluted sulphuric acid is added to complete precipitation, the precipitate is well washed with water, melted until clear of water, drained and dried. An accurately weighed portion of about 5 grams of the clean fat acids is dissolved in alcohol, and titrated, by add- ing normal or other standard solution of alkali in some excess, using phenol-phthalein as an indicator, and bringing back the neu- tral point by a corresponding solution of acid, when the number (n) of c.c. of normal solution of alkali for saturation of 1 gram of the fat acids is found. Then 1000 -r- n = mean molecular weight. Now let x be the desired per cent, of the one fat acid, and b its molecular weight ; y the desired per cent, of the other acid, and c its molecular weight while a is the mean molecu- lar weight as found from titration. Then x 100 ~ , and o c y = 100 x. With stearic and palmitic acids x = 100 a ~ . .28 (6) Determination of Specific Gravity of the Fats. The determination of the liquid fats is made at customary standard temperatures, as of other liquids, by weight in a specific-gravity bottle, or a Spreiigel's tube, or by" a hydrometer. The specific gravity of the waxes and very hard fats is usually taken in the solid state, at customary temperatures, and so stated. In case of many fats, however, the density of the solid state is measurably dependent upon the conditions of solidification. And the speci- fic gravity of the softer solid fats is more often taken in the liquid state, at some stated temperature well above the melting point by Stoddart at 100 C., by Muter at 37.8 C. (100 R)- and usually taking water at the same temperature as the stand- ard. In adjusting the temperature of a specific-gravity bottle or a Sprengel's tube, immersion in water is employed. The water is warmed in a beaker, or other convenient vessel, in which the 262 FATS AND OILS. gravity bottle or tube is securely suspended, the filling up of the exact volume of the liquid fat being adjusted at the noted tem- perature. Then the operation is repeated with water instead of fat, to obtain the divisor representing the unit of density. The Westphal balance is conveniently employed, the counter- poise being suspended and weighed in the oil, contained in a vessel surrounded by water in a larger vessel to which heat is applied. To take the specific gravity of a melted fat by the hydro- meter, a small hydrometer is most convenient, and the oil is contained in a corresponding small cylinder which can easily be immersed in a hot water-bath. A constant water-bath of constant temperature is convenient for habitual use in this operation. Methods by dropping into liquids of known and adjusted density have been proposed by chemists. HAGER (1880) drops melted fat into alcohol, keeping the drops separate, then transfers them to mixtures of alcohol, water, and glycerine, until an equi- librium is found. A list of densities of fats and resins, so deter- mined, is published. 1 A similar method was proposed for butter fat, using methylated spirit, by CASSAMAJOR (1881), and further described under Butter. The counterpart principle, of employ- ing specific-gravity beads of graded density, has been developed by Mr. WIGNER (1876 9 ), especially for melted fats. BLYTH recommends taking the specific gravity of butter fat, clarified and filtered, as a solid at 15 C., by weight in suspension in water, with a weighted tube, on the general plan of solids lighter than water. 3 The ratio of expansion of butter fat, lard, etc., on increase of temperature, has been reported on by WIGNER (1879 4 ). SPECIFIC GRAVITIES OF FAT OILS classified by BENEDIKT, tak- ing figures of ALLEN (1884), and others, at 15 C. : A. Sp. gr. under 0.883. . 1. Liquid waxes from ma- rine animals : Sperm oil 0.875-0.883 2. Oils of unknown com- position : Shark oil 0.865-0.867 African fish-oil 0. 867 l Zeitsch. anal. Chem., 19, 239; Jour. Chem Soc., 38, 70; Phar. Jour. Trans., [3], 10, 287. 2 Analysf, I, 145. 3 1880: Analyst, 5, 76. 4 Analyst, 4, 183. DETERMINATION OF FAT ACIDS. 263 B. 0.883 to 0.912 ...... Oil from cranial cavities : Liquid waxes with glycerides ...... 0.908 C. 0.912 to 0.920 ...... 1. Non-drying oils : Almond oil ........ 0.917-0.920 Peanut oil ......... 0.916-0.920 Olive oil .......... 0.914-0.917 Mustard oil ........ 0.914-0.920 2. Oils of marine animals. none. 3. Oils of land animals : Lard oil ........... 0.915 Tallow oil ......... 0.916 Neat-foot oil ....... 0.914-0.916 Bone oil ........... 0.914-0 D. 0.920 to 0.937 ...... 1. Vegetable oils : (a) Feebly drying, sp. gr. less than 0.930: Cotton-seed oil.. . 0.922-0.930 Sesame oil ....... 0.923-0.924 Sunflower oil ..... 0.924-0.926 (b) Strongly drying oils: Hempseed oil ____ 0.925-0.931 Linseed oil ...... 0.930-0.935 Poppy oil ....... 0.924-0.937 Walnut oil ....... 0.925-0.926 2. Oils of marine animals : Cod-liver oil ....... 0.923-0.930 3. Oils of land animals. . none. E. Sp. gr. above 0.937. . 1. Vegetable oils. Of ca- thartic effect: Croton oil ......... 0.942-0.943 Castor oil .......... 0.960 (Boiled linseed oil.) 2. Oils of land animals . . none. SPECIFIC GEAVITIES OF FAT OILS at 15 C. (MUNICIPAL LA- BOEATOEY OF PAEIS, 1884) : Almond oil ........... 0.917 Olive oil. . .- .......... 0.9163 Peanut oil. . 0.917 " "common.. . 0.9163 264 FATS AND OILS. Colza oil 0.9154 Cotton-seed oil (white) . 0.9254 " " " (brown). 0.930 Beechnut oil 0.922 Linseed oil 0.9325 Cameline oil 0.9252 Walnut oil 0.926 Poppy oil 925 Tallow oil. . Sesame oil 0.9226 Norwegian whale oil.. . 0.9257 South Sea " " . American " " . Cod- liver oil (pale). . " " " (brown) Neat-foot oil 0.9142 Sheep-foot oil 0.9187 . 0.9029. 0.927 0.925 0.928 0.9254 To compare the specific gravity of one oil with that of an- other oil (DONNY, 1864) : Color the one oil with alkanet or other tinctorial matter, and, while both oils are at same tempera- ture, let fall a few drops of the colored oil into a portion of the other in a test-tube. SPECIFIC GRAVITIES OF SOLID FATS at 15 C. (DIETEEICH, 1882) : Wax, white 0.973 Common Eesin, ' yellow 0.963-0.964 American 1.108 " Japan 0.975 Common Resin, Ceresin, white ... 0.918 French 1.104-1.105 " half white. 0.920 Theobroma oil . . . 0.980-0.981 - " yellow... 0.922 Paraffin, medium. 0.913-0.914 Ozokerite, crude . 0.952 Tallow, beef 0.952-0.953 Spermaceti 0.960 " sheep 0.961 " Stearin " 0.971-0.972. SPECIFIC GRAVITIES OF SOLID FATS at 15 C. HAGER (1879) : Butter Fat, clarified 0.938-0.940 several months old 0.936-0.937 Artificial butter 0.925-0.930 Lard, fresh 0.931-0.932 Tallow, beef 0.925-0.929 " sheep 0.937-0.940 Cocoanut oil, fresh 0.950-0.952 " very old 0.945-0.946 Stearic acid, melted 0.946 " " crystallized 0.967-0.969 Beeswax, yellow 0.959-0.962 Ceresin, yellow 0.925-0.928 white 0.923-0.924 " very pure white 0.905-0.908 Common resin. . 1.100 DE TERMINA TION OF FAT A CIDS. 265 SPECIFIC GRAVITIES OF SOLID FATS. At 100 <7., compared with water at 15 G. BENEDIKT (1886), from ALLEN (1884) and KONIGS (1883) : A. Fats not containing glycerides of lower fat acids : 1. Vegetable : Theobroma oil 0.857 Palm oil 0.857 Japan wax 0.873 2. Animal : Lard 0.861 Tallow (beef, or mutton) 0.860 Horse fat 861 Oleomargarin 0.859 B. Fats containing glycerides of lower (volatile) fat acids : 1. Vegetable : Cocoanut oil 0.863 Palm-kernel oil 0.866 2. Animal : Butter fat 0.865-0.868 (7) Determination of the Melting and Congealing Points of Fats. A simple method of finding the melting point is that of the inspection of the fat, taken congealed on the bulb of a ther- mometer, in a beaker of water to which heat is applied, as de- scribed under Stearic acid, a. Sometimes a few drops of the melted fat are taken up in a glass tube of 1 to 3 millimeters internal diameter, bound against .the bulb of a thermometer, congealed, and immersed in a beaker of water or other liquid to which heat is gradually applied. The capillarity of the tube influences the movement of the fat, so that the melting point obtained in this way is somewhat higher than that obtained by observation of the fat taken as a coating of the thermometer bulb. Some observers have wider tubes taking a " funnel-tube " of about 2 centimeters diameter in the upper portion and 7 millimeters diameter in the lower portion a few drops of the melted fat being taken and congealed on the side of the wider part, just above the narrowing" of the tube. Some authors designate the " beginning of the melting point " as the temperature at which the fat begins to flow down the side of the tube, and " end of the melting point " as that at which it becomes wholly liquid. The sinking point of HEHNER and ANGELL is the temperature at which a glass bulb of 3.4 sp. gr. and 1 c.c. in volume will sink in the melted fat. The bulb is blown from a piece of glass tub- ing of } inch diameter, and is drawn off pear-shaped with a very 266 FA TS AND OILS. tapering end. The bulb should displace as nearly as possible 1 c.c. of water, and should be so weighted by the introduction of mercury as to weigh 3.4 grams. Differences of 0.005 to 0.01 weight have little effect on the results. The following directions for taking " the sinking point " of butter will indicate the method of application to any fat. Of the butter 20 to 30 grams are melted in a beaker over the water-bath, then poured into a test-tube J inch wide and 6 inches long, filling to within two inches of the top. The tube is kept warm until the fat is clarified by the settling of the water, curd, and salt, when the fat is solidified at 15 C. by immersing the tube in water of this temperature. (The cone of depression on the top of the fat serves to indicate its relative fusing point. Pure butter fat shows only a slight depression, while admixtures with fats of high melting points show a considerable hollow cone.) The tube is now placed in about one liter of cold water, in a beaker, the test-tube being se- cured so that the top of the fat is about 1 inches below the sur- face of the water. Heat is now applied to the beaker by a sand- bath or by asbestos felt, over a lamp. The surface of the fat is made level, and the weighted bulb placed thereon. The water is stirred from time to time. A thermometer is placed in the water, with the bulb near the surface of the fat, and the temperature read off just as the globular part of the bulb has sunk beneath the fat. Hehner and Angel 1 found the average sinking point of the fat of 24 genuine butters to be 35.5 C. (96 F.), with extremes of 34.3 to 36.3 C. (93.7-97.3F.) Of the fatty acids of but- ter fat, 40.5 to 42.1 C. Of beef tallow, average, 50.6 C. (48.3 ' to 53.0 C.); of mutton tallow, 50.9 C. average (50.1 to 51.6 C.) ; of lard, 41.1 to 45.3 C. ; of stearin, 62. 8 C.; of cacao but- ter, 34.9 C. ; of palm oil, 39.2 C. To calculate the mean sinking point of a mixture of two fats of known composition, having their respective sinking points (S x and S 2 ), and percentages in the mixture (F x and F s ) : ^ = sinking point of the mixture. Kesults of admixture are compared with calculated averages, as follows : 66.7$ butter and 33.3$ tallow, 43.1 C. found, 42.08 C. calculated. 73.0 27.0 " 42.3 " ' 40.2 " 10.0 " 90.0 " 48.8 " 49.6 85.0 " 15.0 " 38.1 38.1 " H ASS ALL uses a light bulb, weighing 0.18 gram, and of the volume of about 0.5 c c., sunken in the solidified fat in a test- DE TERM IN A TION OF FAT A CIDS. 267 tube \ inch wide and 4 inches high. " The rising point " is taken at the temperature when the bulb rises, during the gradual application of heat, by the softening of the fat. Hassall also re- cords "the point of clearance" when the fat becomes clear, this point being usually 1 or 2 C. above the rising point. The congealing point is more often inconstant than the melt- ing point. It is sometimes taken as the point of commencing turbidity in a mass of melted fat, and sometimes as the point of formation of a coherent solid. DALICAN made determination of the congealing point by use of a test-glass 10 or 12 centimeters (4 or 5 inches) long and 1.5 ( or 2 centimeters (0.4 or 0.5 inch) wide. The tube is" two-thirds filled with the fat, warmed, and the fat stirred with a glass rod. to liquefy the contents. A ther- mometer, graduated in fifths, is suspended in the fat, loosely ad- justed by a perforated cork at the mouth of the tube, the bulb resting in the centre of the fat. When crystallization commences on the edge the mass is stirred with the bulb of the thermometer, by which the temperature is caused to fall a little, after which it soon rises to near the point before noted, and when it stands constant for two minutes the temperature is taken as the con- gealing point. Some fats, in congealing, show a rise of tem- perature after the solidification has fairly set in, and the maximum of this rise is sometimes taken as the congealing point (see the table at p. 271). MELTING AND CONGEALING POINTS of mixtures of Stearic and Palmitic acids (HEINTZ) : Stearic acid. Palmitic acid. Melting point. Congealing point. 100^ 0^ 69.2 C. .- C. 90 10 67.2 62.5 80 20 65.3 60.3 TO 30 62.9 59.3 60 40 60.3 56.5 50 50 56.6 55 40 60 56.3 54.5 32.5 67.5 55.2 54 30 70 55.1 54 20 80 57.5 53.8 10 90 60.1 54.5 100 62.0 268 FA TS AND OILS. CONGEALING POINT of mixtures of Solid fat acids (' * Stearic acid ") and Liquid fat acid (" Oleic acid ") as obtained from Tallow (DALICAN, 1880) : Congealing point. u C. ' ' Stearic acid " in 100 parts of Tallow. " Oleic acid " in lift parts of Tallow. 35 25.20 parts. 69.80 parts. 35.5 2640 68.60 36 27.30 67.70 36.5 28.75 66.25 37 29.80 65.20 37.5 30.60 64.40 38 31.25 63.75 38.5 32.15 62.85 39 33.45 61.55 39.5 34.20 60.80 40 35.15 59.85 40.5 36.10 58.90 41 38.00 57.00 41.5 38.95 56.05 42 39.90 55.10 42.5 42.75 52.27 43 43.70 51.30 43.5 44.65 50.35 44 47.50 47.50 44.5 49.40 45.60 45 51.30 43.70 45.5 52.25 42.75 46 53.20 41.80 46.5 55.10 39.90 47 57.95 37.05 47.5 58.90 36.10 48 61.75 33.25 48.5 66.50 28.50 49 71.25 23.75 49.5 72.20 22.80 ' 50 75.05 19.95 50.5 77.10 17.90 51 79.50 15.50 51.5 81.90 13.10 52 84.00 11.00 52.5 88.30 6.70 53 92.10 2.90 DETERMINA TION OF FAT A CIDS. 269 MELTING AND CONGEALING POINTS of the Acids of Solid Fats (HiJBL). Fat acids of Melting. Congealing. Oleomargarin 42.0 C. 39.8 C. Palm oil 47.8 42.7 ' Tallow 45.0 43.0 Wool fat 41.8 40.0 Cacao butter 52.0 51.0 Mace oil (nutmeg oil) 42.5 40.0 Butter fat 38.0 35.8 Cocoanut oil 24.6 20.4 MELTING AND CONGEALING POINTS of the Fat Acids of Oils (BACH). Fat acids of Melting. Congealing. Olive oil 26.5-28.5 C. Not under 22 C Cotton-seed oil 38.0 35.0 Sesame oil 35.0 32.5 Peanut oil 33.0 31 Sunflower-seed oil 23.0 17.0 Rape oil 20.7 15.0 Castor oil 13.0 2.0 2/0 FATS AND OILS. CONGEALING POINT of mixtures of certain proportions of com- mercial Stearic acid of stated melting points, as obtained from Tallow (SCHEPPER and GEITEL, 1882). Congealing point of the tallow -fat acids. The tallow-fat acids containing in per cent, of "Stearic acid " of congealing point of 48 C. 50 C. 52 C. 54.8 C. 10 C. 3.2 2.7 2.3 2.1 15 7.5 6.6 5.7 4.8 20 13.0 11.4 9.7 8.2 25 19.2 17.0 14.8 12.6 30 27.9 23.2 21.4 18.3 35 39.5 34.5 30.2 25.8 36 42.5 36.9 32.5 27.6 37 46.0 40.0 34.9 29.6 38 49.5 42.6 37.5 32.0 39 53.2 458 40.3 34.3 40 57.8 49.6 43.5 37.0 41 62.2 53.5 47.0 40.0 42 66.6 57.6 50.5 42.9 43 71.8 62.0 54.0 46.0 44 77.0 66.2 58.4 49.8 45 81.8 71.0 62.6 53.0 46 87.5 75.8 67.0 56.8 47 93.3 80.9 71.5 60.8 48 100.0 87.2 76.6 65.0 49 93.0 81.7 69.5 50 100.0 87.0 74.5 51 93.5 79.8 52 100.0 84.8 53 .... 90.1 54 .... 95.3 54.8 100.0 CONGEALING POINTS of Oils (MUNICIPAL LABORATORY OF PARIS). Beechnut oil 17.5 C. Cameline oil 18 Poppy oil 18 Linseed oil 27.5 Hempseed oil 27.5 Olive oil . _i_ 2C. Cod-liver oil Rape oil , .... 3.75 Colza oil ... 6.25 Peanut oil... . 7 Almond oil. . . 10 DETERMINA TION OF FA T ACIDS. 71 MELTING AND CONGEALING POINTS of Solid Fats, WIMMEL (1868). Melting point. In congealing be- come turbid at In congealing, temp, rises to Tallow, beef, fresh. . . . " " old . 43 C. 42.5 47 50.5 41.5-42 31-31.5 32.5 52.5-54.5 33.5-34 24.5 30 36 42 43.5-44 62-62.5 | c 44-44.5 f 33 C. 34 36 39.5 30 19 20 36-37 C. 38 40-41 44-45 32 19.5-20.5 25.5 45.5-46 27-29.5 22-'.'3 21.5 35 39.5 41.5-42 3low the melt- ithout devel- r armth. " sheep, fresh.. . " " old. . . . Lard Butter fat fresh Firkin butter 24 40.5-41 205 20-20.5 21 24 38 33 ,ongeal just b< ing point w opment of \\ Japan wax Cacao butter Cocoanut oil. Palm oil, fresh, soft.. " " hard . old Mace oil (nutmeg oil). Beeswax, yellow Spermaceti.. . Other Authorities Cholesterin 145-146 Isocholesterin 137-138 Ceresin (ozokerite). . . . Cetyl alcohol 58-84 50 Ceryl alcohol Myricyl alcohol 79 85 2/2 FA TS AND OILS. STEARIN PERCENTAGE IN OLEOMARGARIN, ACCORDING TO CONGEAL- ING POINTS. 1 Congealing at C. Per cent, of Stearic ac. o/48(7. 2 Congealing at C. Per cent, of Stearic ac. of 48 C. Congealing atC. Per cent, of Stearic ac. of8C. 5.4 20 12.1 35 39.5 6 6.3 21 13.2 36 43.0 7 0.8 22 14.5 37 46.9 8 1.2 23 15.7 38 50.5 9 1.7 24 17.0 39 54.5 10 2.5 25 18.5 40 58.9 11 3.2 26 20.0 41 636 12 3.8 27 21.7 42 68.5 13 4.7 28 23.3 43 73.5 14 5.6 29 25.2 44 78.9 15 6.6 30 27.2 45 83.5 16 7.7 31 29.2 46 89.0 17 8.8 32 31.5 47 94.1, 18 9.8 33 33.8 48 100.0 19 11.1 34 36.6 KUDORFF (1872). Melting point. Congealing point. In congealing, tem- perature rises to Yellow wax. . . . White wax .... Paraffin 63.4 61.8 49.6 61.5, 62.6, 62.3 61.6 49.6 M 52 5 54 53 U 53 52 9 it 52 7, 53 2 52.7 Spermaceti Stearic acid, commercial Japan wax 43.5 44.1, 44.3 ( 55.3 < 56.2, 56.6 ( 56.0, 56.4 50 4, 51 43.4 44.2 55.2 55.8 55.7 50.8 Cacao butter. . . Mace oil (nut- meg) 33.5 70, 80 27.3 41.7, 41.8 Tallow, sheep. . u a 46.5, 47.4 43.5, 45.0 32, 36 27, 35 j a few de- ( grees. 'BENEDIKT'S "Analyse der Fette,"p. 131. 2 Congealing point. DE TERMINA TION OF FAT A CIDS. 273 (8) Calculation of the constituent Fat Acids and Neutral Fats, and the value for production of Fat Acids and Gly- cerin. Let n equal the number of c.c. of standard solution required to saturate the free fat acids of 1 gram of the material, taken up in alcoholic solution, using phenol-phthalein as an indicator, and titrating with alkali at once. Let m be the number of c.c. of the standard alkali of the value of 1 c.c. of normal alkali. In normal solution, m = 1 ; in decinorrnal solution, m 10, etc. Let c be the number of c.c. of normal alkali taken to saturate both the free and combined a,cids in 1 gram of fat, as directed under Determination of Mean Molecular Weight (p. 261). Let a be the mean molecular weight of the fat, found from c, as di- rected on p. 261. Then per cent, of free fat acids = 1Q ^. Per cent, of neutral fat = 100 per cent, of free fat acids. (9) Distinction of Fat Oils by Solubility in Glacial Acetic Acid (VALENTA/ 1884). When the oil, and glacial acetic acid of sp. gr. 1.05662, in equal volumes, are mixed in a test-tube, and if solution does not occur at ordinary temperatures, the mix- ture warmed, it will be found that 1. At ordinary temperatures (15-20 C.) Castor oil and Olive oil are perfectly dissolved. 2. At temperatures from 23 C. to the boiling of the acid, solution is obtained with Palm oil, Mace oil, Cocoanut oil, Palm- kernel oil, Olive oil, Theobroma oil, Sesame oil, Almond oil, Cotton-seed oil, Peanut oil, Beef Tallow, American Bone oil, Cod-liver oil, Press Tallow. See table below. 3. Imperfectly dissolved at boiling of the acetic acid Rape oils. For distinctions between members of the 2d class the mix- ture is heated in the test-tube until solution is effected, when a thermometer is introduced, and, as the mixture cools, the tempe- rature of commencing turbidity is noted: l Ding. pol. Jour., 252, 296; Zeitsch. anal. Chem., 24, 295; Jour. Chem. Soc., 48, 93; 46, 1078. 274 FA TS AND OILS. Name of the Fat. Sp. Gr. of the fat. Turbid at Remarks, Palm oil 23 C. Fresh fat. Mace oil 27 Cocoanut oil 40 Palm-kernel oil 48 Old rancid fat. Olive oil, green 0.9173 85 Second pressed, Theobroma oil 105 probably con- taining olive- kernel oil. Sesame oil 0.9213 107 Almond oil 0.9186 110 From sweet al- Cotton seed oil 0.9228 110 monds. Olive oil, vellow 0.9149 111 Oil first pressed. Peanut oil 0.9193 112 Apricot oil 0.9191 114 Beef Tallow 95 Very fine hard Bone Fat (American) . Cod-liver oil 90-95 101 tallow. Press Tallow. . . 114 Melt. 55.8 C. Hard, fine. Solubilities of Oils in Glacial Acetic Acid, BARNES (1876). 1 volume of glacial acetic acid dissolves of fixed oil of almonds, 7 vols. ; olive oil, 8 vols. ; cod-liver oil, 7 vols. ; linseed oil, 7 vols.; turpentine oil, J vol.; copaiba oil, ^V vol.; lemon oil, 2 vols. ; juniper oil, 1 vol. ; all proportions of castor oil and cro- ton oil. SEPARATION OF MINERAL OILS AND OTHER NON SAPONIFIABLE BODIES FROM THE FAT OILS OR GLYCERiDES. 1 The determination, in qualitative or quantitative result, of mixtures of the FAT OILS or glycerides with mineral oils (petroleum and shale oils), tar oils (neutral coal oils), paraffins, rosin oils, resins, and waxes. Excluding the few instances in which a volatile hydrocarbon or *E. GEISSLER, H. EAGER, 1880: Summary in Zeitsrh. anal. Chem., 19, 114. Lux, mS'.Zeitsch. anal. Chem., 24, 357. A. H. ALLEN, 1881: Chem. News, 44, 161; 43, 267. Benedikt: " Analyse der Fette," 1886, pp. 102-126: " Nachweis und quantitative Bestimmung solcher fremder Beimengungen, welche in der Fettsubstanz gelost oder mit ihr zusammengeschmolzen sind." SEPARA TION OF MINERAL OILS. 275 mineral oil can be separated from fixed oils by distillation, either with or without steam, the analysis requires first the sapo- nification of the saponifiable substances. Of the bodies named above with the mineral oils, only the resins are fully saponifiable, besides which only the waxes saponify at all. The waxes give the acids to alkalies in production of soap-like compounds, while the base, unlike glycerin, remains undissolved after the saponifi- cation. When the fat is readily saponifiable, and especially when the non-saponifiable substance is not much soluble in aqueous soap solution, simple saponificatien, with dilution of the mixture, serves for the separation, more satisfactorily with large quantities: 50 grams material in a 300 c.c. flask, with 50 c.c. alcohol and 40 grams caustic soda (which will dissolve clear in alcohol), digested with stirring at about 90 C. until dissolved, then boiled for 40 minutes, 150 c.c. water added (while boiling), boiled 50 minutes longer, and poured into a cylindrical separator. When the non- saponifiable oil has risen to a clear layer, this is poured off into a tared dish, the surfaces of the separator and the liquid washed with a few portions of ether, the ether evaporated, and the weight taken. But in general the mineral oils and resin oil dissolve in soap solution to an extent preventing full recovery by the above-given method. The solubility is diminished by largely diluting the soap solution, but this is quite impracticable because it decom- poses the soap itself, giving a mixture turbid with free fat acids. Therefore it is necessary to employ a solvent not miscible with aqueous solutions as ether or petroleum benzin by which the paraffin oil or like unsaponified matter may be " extracted " from the solution. This may be done by " shaking out " in the ordi- nary way. Ether is almost always the best solvent, giving least difficulty in emulsification, though often troublesome in this respect. To avoid permanent emulsification the agitation may be done by gently elevating alternate ends of the separator. The details are given by ALLEN and THOMPSON (1881) in effect as follows : Of the material 5 grains are taken, digested with 25 c,c. of an alcoholic soda solution (80 grams caustic soda per liter) until saponification is complete and the alcohol evaporated, treated with 50 c.c. of hot water to dissolve the soap, and the liquid in- troduced into a separator of about 200 c.c. capacity. 20 or 30 c.c. of water are added, and when cold the liquid is shaken with 30 to 50 c.c. of ether. Separation can be promoted by addition of a little alcohol. From three to four successive portions of 276 FA TS AND OILS. ether are usually required. The residue obtained in a .tared beaker or flask by evaporation of the ethereal solution is weighed. With use of petroleum benzin upon a dried saponified mass of the material under examination, the authors last quoted pro- ceed as follows : 10 grams of the material, in an evaporating- di^h of five inches diameter, are digested with 50 c.c. of an eight- per-cent. alcoholic solution of caustic soda, stirring and gently boiling, adding 15 c.c. of methyl alcohol, and boiling again. About 5 grams of sodium carbonate are now stirred in, and then 50 to 70 grams of ignited clean sand, the mixture dried for 20 minutes on the water-bath, transferred to an extraction apparatus, exhausted with petroleum benzin (wholly volatile at 80 C.), and the residue, after evaporation of this solvent, weighed as non- saponifiable matters. Ignited, these should leave only a trace of ash. In presence of much mineral oil or resin oil a portion of soap is taken up by the benzin, and the extraction of the solu- tion by ether is more trustworthy. Extraction of the dried soap with benzin is carried out by DONATH (18T3), in analysis of stearin candles for paraffin, as fol- lows : 6 grams are saponified by digestion with alcoholic potash, the alcohol evaporated, the residue dissolved in water, and the solution precipitated with calcium or barium chloride. If much paraffin be probably present, some sodium carbonate is added, to give earthy carbonate to the precipitate. The precipitate holds the paraffin completely, and is washed on the filter with hot water, drained and dried at 100 C., and exhausted with petro- leum benzin in an extraction apparatus. The error does not overgo 0.3$ of the paraffin. BENEDIKT (1886) recommends the use of a liquid extraction apparatus in treating the aqueous soap solution with ether or petroleum benzin. ^ See under " Extraction Apparatus For Liquids," p. 38. Estimation of non-saponiftdble admixture may be made by calculation of the Kottstorfers number (factor of saponification) (p. 254) of the mixture (<%) compared with that of the pure saponifiable fat, as known (a). Then the per cent, of non-saponi- fiable matter (1ST) = 100 iA a Small percentages of fat in mixture with hydrocarbons may be estimated by a quantitative determination of the glycerin re- sulting from saponification, using the permanganate- oxidation method. (See Glycerin, /*). Examination of the non-saponifiable matters. Of these the ordinary articles are as follows: Liquid petroleum oils, shale oils, ESTIMA TION OF FREE FA TTY A CWS. 277 tar oils, resin oils ; Solid paraffin, ceresin, solid fat alcohols, eholesterin, isocholesterin. Of the liquids, the Mineral Oils from petroleum and from shale are distilled over at 250-300 C., and of sp. gr. 0.855 to 0.900 ; vaselin oil at 250-350 C., and of sp. gr. 0.900 to 0.930. The Tar Oils distilled from coal-tar as " dead oils," from 240 C. to 350 C., 1 purified by soda -lye, are used as lubricating oils, and have sp. gr. above 1, indeed above 1.010. As to Rosin Oils, see page 280. Of the solids. Paraffins are white, odorless, of sp. gr. 0.869 to 0.943, distil without change, are graded by congealing points 38 to 82 C., and dissolve in alcohol. Ceresin or Ozokerite is not distilled, is purified by sul- phuric acid, and agrees in general with paraffin in specific gra- vities and congealing points. In the elaidin test the mineral oils remain nearly or quite unchanged. Iodine numbers (p. 258) distinguish mineral oils from rosin oils. Glacial acetic acid, 100 grams, at 50 C., dis- solves 2.6 to 6.5 grams of various mineral oils; about 17 grams rosin oils. In determining these solubilities 2 c.c. of the oil to be tested may be treated in a stoppered test-tube with 10 c.c. glacial acetic acid, warming in a water-bath at 50 C. and agitat- ing, filtering through a filter just moistened with the glacial acid, and determining the quantity of acetic acid in a weighed portion of filtrate by titrating with standard alkali. Acetone is used for separation of mineral oils from rosin oils, as specified under Rosin Oils. For the solid non-saponifiable matters the melting points are observed (see Melting and Congealing Points of Solid Fats, p. 271). Treated with an equal weight of anhydrous glacial acetic acid, boiling some time with a return-condenser, the fat alcohols (cetyl alcohol, etc.) dissolve completely, cholesterin crystallizes on cooling, and paraffins or ceresins swim undis- solved while hot and congeal on cooling. Non sa2^onifiable matters (hydrocarbons or other bodies') in the Fats and Waxes. (ALLEN and THOMPSON, 1881.) By sapo- nificatioii and extraction with petroleum benzin there were found of unsaponifiable matter in Lard, 0.23$ ; Cotton-seed oil, 1.64$; Olive oil, 0.75$; Rape oil, 1.000; Cod-liver oil, 1.32$; Japan wax, 1.14$ ; Spermaceti, 40.64$ ; Beeswax, 52.38$ ; Rosin oil, 98.72$ ; Mineral oils, 99.90$. ESTIMATION OF FREE FATTY ACIDS IN FATS.* The plan of 1 A summary of the fractions of coal-tar distillation is given under Phenol. 2 GEissLER, 1878: Ding. poL Jour., 227, 92; Zeitsch. anal. Chem., 17, 393; Jour. Chem. Soc., 34, 534. BURSTYN, 1872. HAGER, 1877. WIEDERHOLD, 278 FA TS AND OILS. Geissler, an ethereal solution of the oil being titrated with stan- dard alcoholic alkali, to the neutral reaction of phenol- phthalein, is generally applicable, and capable of variation to meet techni- cal demands. As a solvent for the fats and oils, ether or alcohol- ether may be employed, or (GROGER) 5 to 10 parts of hot alcohol may be used. The solvent must be free from acidity. Ether is neutralized for this purpose by adding to a portion a drop or two of phenol-phthalein solution, and then drops of alcoholic al- kali, until the color of the indicator begins to appear after shak- ing. For one part of the oil, weighed for estimation, 2 or 3 parts of ether are usually sufficient. The alcoholic alkali solution may be made with good alcoholic potassa, and alcohol free from fusel oil (if need be, filtered through animal charcoal), and in most cases should be very dilute, approximately 20th normal, or weaker. After titrating the ethereal solution of the weighed quantity of the oil, with the alcoholic alkali, just the required quantity of this is again taken and titrated with standard acid. Generally decinormal acid may be used, or a solution of acid in which 1 c.c. corresponds to 0.001 gram of the fat acid under estimation. It is better to express the results in percentages of fatty acids in the fats examined, provided a representative acid can be taken as n per cent, of free acid as oleic acid. BURSTYN'S numbers, or degrees of acidity in fats, are the c.c. of normal al- kali solution neutralized by 100 c.c. of fat ; or (KOTTSTORFER) 100 grams of the fat. ARCHBUTT distils a mixture of the oil with purified methyl alcohol, repeating once, and titrates the distillate. Separation of Common Resin from Fats and Soaps. A satisfactory method, trustworthy for either Quantitative or Quali- tative purposes, is that of GLADDING/ dependent on ether-solu- bility of the silver salt, and corresponding to the separation of oleic acid by ether-solubility of its lead salt. Fatty salts of silver are insoluble, resin salt of silver soluble in ether. The free fat acids are to be obtained, with the rosin, neutral fats being first saponified, soaps being treated with acid, and the total free fatty acids washed with water and dried if need be. For quantitative separation the directions are as follows : About 0.5 of the fat acids is accurately weighed into a small flask, and 20 c.c. of 95 per cent, alcohol added for solution. A 1877. KOTTSTORFER, rancid butters, 1879: Zeitsch. anal. Chem., 18, 436. GROGER, 1882: Ding. pol. Jour., 244, 307. ARCHBUTT: Repert. /. anal. Chem., 4, 330. 1 1882: Am. Chem. Jour., 3, 416; Jour. Chem. Soc., 42, 663; Chem. News, 45, 169; Zeitsch. anal. Chem., 21, 585. SEPARA TION OF RESIN. 279 drop of phenol-phthalein is added, then a saturated alcohol solu- tion of caustic potash is added by drops until the color of an alka- line reaction is obtained after agitation, when one or two drops of the alcoholic potash are added in excess. The liquid is now held at the temperature of boiling alcohol for ten minutes, while the flask is loosely corked. When cold the contents of the flask are transferred to a 100 c.c. graduated cylinder, rinsing with con- centrated ether, and diluting with this solvent just to the 100 c.c. mark. The cylinder is well corked and shaken for a mo- ment, and about 1 gram of pure silver nitrate, neutral in reaction, rubbed to an impalpable powder, is added to the solution, and the whole shaken vigorously for 10 or 15 minutes until the pre- cipitate will settle clear. The volume is restored, if need be, to 100 c.c. by adding ether and shaking, and of the supernatent liquid 50 to 70 c.c., as an aliquot part (in c.c.) of the whole 100 c.c., is siphoned off by means of a slender siphon (previously fllled with ether) into a second stoppered 100 c.c. cylinder, pass- ing the liquid through a small filter if not perfectly clear. The siphon and filter are rinsed with a little ether into the second cylinder. To make certain that the silver precipitation is com- plete, a little pulverized silver nitrate is shaken up with the clear liquid. JS"ow a mixture of 7 c.c. of hydrochloric acid (sp. gr. about 1.12) and 14 c.c. of water are added, and the whole sha- ken vigorously until the silver is wholly converted to chloride. When the precipitate has settled perfectly, the volume (n c.c.) of the ethereal liquid is read, and an aliquot part (o c. c. ) of this ethereal solution is siphoned off into a tared beaker, rinsing the siphon into the beaker with a little ether, and the ether eva- porated gently, to obtain the weight of the residue. The re- sidue is the resin, representing, through both the aliquot divi- sions, the entire resin in the fat taken. A small but nearly constant proportion of oleic acid is taken up as silver salt by the ether, and left with the resin in the final residue ; therefore a correction is made as follows: for every 10 c.c. of the ethereal solution of silver salt siphoned off, 0.00235 gram is deducted Then having w as the number of grams of residue obtained in the analysis, and a as the number of grams of fat taken for analysis, to find x the per cent, of resin in the fat acids, the cal- culation is as follows : 10000 n w 2.35 x = . a mo a For qualitative purposes the same operation, performed in good, strong stoppered cylinders or test-glasses, without weigh- 280 FA TS AND OILS. ing or measuring portions, will give trustworthy results. The iinal residue is to be examined, when cold, as to brittleness, solubilities, etc., for identification of resin of turpentine or com- mon rosin. ROSIN OILS. Eesin Oils. Harzdle. 1 Of complex and va- riable composition, consisting of polymeric terpenes and other hydrocarbons, and oxidized bodies. It is obtained as a product of the destructive distillation of common resin (resin of turpen- tine). Rosin oils are known by specific gravity and distillation (&), by sensible properties (&), and by reactions (d). Separated, in most cases, best by saponification and ether- solution (e). Found with other oils (g). a. A liquid of a brownish-yellow color, and a violet to blue fluorescence. Sp. gr. 0.96 to 0.99. When distilled a portion passes over below 250 C., considerable below 300 C., and al- most all below 360 C. (REMONT). The lightest fractional distil- lates, when obtained, boil at 103 to 106 C., and from light resin oil distillates boiling at 80 C. have been obtained. Strong dextro-rotatory powers are possessed by some rosin oils ; others are inactive, still others levo-rotatory. 5. Rosin oil has a characteristic taste, and an odor of com- mon rosin, the odor of refined rosin oil obtained only after heating. G. Insoluble in water, slightly soluble in alcohol, soluble in all proportions in ether, chloroform, carbon disulphide, pe- troleum benzin, acetone, petroleum lubricating oils, essential oils, and glyceride oils. d. Not saponifiable (see e). Shaken with dry stannous chloride, or better, stannous bromide (ALLEN, 1884), a violet color is slowly obtained. Nitric acid, chlorine, bromine act as oxidizing agents, w^th uncertain force, sometimes with vio- lence. With sulphuric acid, blackening occurs. The vapor burns with a smoky flame. 1 History and description: REMONT, 1880-81: Bull. Soc. Chim., |2], 33, 461, 525; Jour. Chem. Soc., 38, 683; 40, 202. SCHAEDLER: "Die Technologic der Fette und Oele der Fossillien, sowie der Harzole und Schmeirmittel," 1885-86, Kapitel xvi. Composition: TILDEN, 1880: Ber. d. chem. (res., 13, 1604; J',ur. Chem. Soc., 40, 101. KELBE and WORTH, 1882: Ber. d. chem. Ges., is,308. RENARD, 1882: Bull. Soc. Chim., [2], 36. 215: Jour. Chem. Soc, 42. 64. Analysis: DEMSKI and MORAWSKI, 1885: Ding. pol. Jour., 258, 82', Analyst, 10, 231. ROSIN OILS. 281 e. Separation of rosin oils from fixed oils by distillation is slow and imperfect, but may yield a distillate of rosin oil suf- ficient for identification by odor and other properties. Separa- tion from glycerides by saponification of the latter is more satis- factory, but, as with mineral oils, the result is not well attained by simple aqueous dilution of the soap solution. Rosin oils are somewhat soluble in strong solutions of soap, and dilution of the solution separates fat acid from the soap. Saponifying with alkali in alcoholic solution, expelling the alcohol, and diluting with water short of turbidity of the soap solution alone, the liquid is shaken out with portions of ether, the ether evapo- rated from the ethereal separate, and the residue tested by odor when hot, by taste, by stannous chloride, and by gravity, for rosin oil. Separation from Mineral Oils by acetone as a solvent is done as follows (DEMSKI and MORAWSKI, where cited). Rosin oils dis- solve in all proportions of acetone. 50 c.c. of the sample of oil are shaken up several times with 25 c.c. of acetone in a 100 c.c. graduated cylinder, and then left at rest for some time. If the liquid separates into two layers, 10 c.c. of the upper are drawn off, and the amount of oil in it determined after evapora- tion of the acetone. The density of this residue is judged by adding water to a few drops of it, and then alcohol until the oil just begins to sink. Finally it is required to determine the amount of rosin oil which it is necessary to add to the sample of oil under examination to enable it to dissolve in half its volume of acetone. As soon as perfect solution is effected the liquid gives a fairly permanent froth when shaken. With American mineral oils 35^ of rosin oil is at once detected by its solubility in acetone ; with Caucasian and Wallachian oils 50$ is at once detected. g. Rosin oils are used legitimately for lubricating purposes. As adulterants they have a wide distribution, in lubricating oils, in linseed oil, olive oil, and even in castor oil and the essen- tial oils. Rosin Grease is a saponaceous paste made by mixing slaked lime with rosin oil. DRYING AND NON-DRYING OILS, DISTINCTIONS BETWEEN. (1) Elaidin Test. The action of fuming nitric acid, or of nitric acid with metallic copper or metallic mercury, or the action of a concentrated solution of mercuric nitrate, in warm digestion, noting the result each quarter of an hour, and later each hour. Non-drying oils are converted into a solid mass, termed elaidin, 282 FATS AND OILS. a glyceride of elaidic acid (p. 247), which is isomeric with oleic acid. The reaction, therefore, is not an oxidation, though ef- fected by an oxidizing agent. (2) Warming effect of Sulphuric Acid (MAUMENE, 1881 ; AL- LEN, 1881 '). The sulphuric acid should be anhydrous. It may be prepared by heating to 320 C., and cooling to the tempera- ture of the oil. Of the concentrated acid 10 c.c. are taken in a beaker, and 50 grams of the oil are added, when the mixture is slowly stirred with the thermometer bulb until, after rising, the thermometer begins to fall, when the degree is noted, the initial temperature of the oil and acid is subtracted, and the elevation of temperature obtained. ELEVATION O! 1 TEMPERATURE. Maumene. Paris City Laboratory. Non-drying : Olive oil 42 C. 51-55.5 C. Peanut oil. . . 62 Cotton-seed oil 69.5 Sweet-almond oil. . 53.5 Beechnut oil 65 Castor oil 47 Sheep-foot oil. 51.5 Olein (oleic acid) of saponification. . Drying : Poppv. . 70.5 47.5 73 rtv' Hemp 98 Walnut 101 Linseed 133 114.5 Train oils : Cod-liver oil 103 " " brown 89.5 Sperm oil #3.5-73 (3) Iodine numbers. The fat acids of the drying oils have a A. H. ALLEN, Analyst, 6, 102. DRYING AND NON-DRYING OILS. 283 greater capacity for iodine combination than the non-drying oils. See pp. 258, 259. (4) Oxygen-absorption. The greater the u drying " capacity of an oil, the more oxygen it absorbs on a given exposure to air. Precipitated metallic lead is added to favor oxidation and enable a measure of the oxidation to be made (LivACHE, 1883 '). The lead is prepared by precipitating lead acetate solution with zinc, at once washing the precipitate with a little water, then with al- cohol, then with ether, and drying in a vacuum. In a large tared watch-glass one gram of the lead is taken, and from 0.6 to 0.7 gram of the oil is dropped slowly upon the lead, and the weight of all taken, giving the weight' of oil. The test is set aside, at medium temperature, in a place free from vapors or dust, and the weight taken after 18 hours, to 4 or 5 days, or longer. INCREASE < 5F WEIGHT. OF THE FAT ACIDS. After 2 days. After 7 days. After 8 days. Linseed oil 14.3$ IK Walnut oil 7.9 6 Poppy oil . 6.8 3.7 Cotton-seed oil 5.9 0.8 Beechnut oil 4.3 2.6 Colza oil 0.0 29$ 2.6 Rape oil 0.0 2.9 0.9 Olive oil 0.0 1.7 0.7 Oxygen-absorption has been studied by W. Fox, a who de- termines the oxygen absorbed by direct estimation. About 1 fram of the oil is sealed in a tube of 100 c.c. capacity, or 5 or drops of the oil (weighed) are placed m a well-ground, stop- pered flask of 200 c. c. capacity ; the whole heated in an oil-bath at 104. 5 C. (22'0F.) for about four hours; the tube or flask opened under water, the remaining gas measured in a eudio- meter, also the remaining oxygen estimated by pyrogallol and potash, using the precautions and corrections of gas analysis, for estimation of the quantity of oxygen gas taken up by the weighed quantity of oil. The author finds that avidity for oxy- Compt. rend., 97, 1311; Jour. Chrm Sor., 46, 532. 2 1883: Analyst, 8, 116; New Sem., 12, 367. 284 FATS AND OILS. gen is influenced largely by presence of fat acids formed by standing open to the air, and that the differences thus due to age and exposure are removed by heating the oil to 204 C. (400 F.) The author holds the value of lubricating oils to be largely dependent on- their non-absorption of oxygen. Also, he claims that his method gives the surest detection of cotton-seed oil in admixture with olive oil. He gives the following results in c.c. of oxygen absorbed : Linseed oils Baltic Sea, 191 ; Black Sea, 186 ; Calcutta, 126 ; Bombay, 130 ; American, 156. Cotton- seed oil, refined, 24.6; rape-seed oil, brown, 20; rape-seed oil, colza, 17.6. Olive oil, highest, 8.7; lowest, 8.2. LINSEED OiL. 1 Leinol. Huile de lin. Flachsol. Chiefly the triglyceride of Linoleic Acid (p. 249),C 3 H 5 (C 16 H 27 O 2 ) 3 =794.-- A lixed oil expressed from flaxseed, the seed of Linum usitatis- simum, of which it should form as much as 25 per cent. See Drying and Non-drying Oils, under Fats, p. 281. a. A yellowish or yellow oily liquid, of the sp. gr. about 0.936 (U. S. Ph.), at 15 C. 0.9347 (SCHUBLER), 0.9325 (Sou- CHERE), 0.930-0.935 (ALLEN). Specific gravity of the total fat acids, at 100 C., 0.8599 (ARCHBUTT and ALLEN). Congeals at 16 C. after a few days (GUSSEROW) ; 27 C. (CHATEAU). Melts at 16 to 20 (GLASSNER). The total fat acids con geal at 13.3 C. (HUBL) ; melt at 17.0 (HUBL). Itoiled Linseed Oil has sp. gr. 0.940-0.941. J. Linseed oil has a slight peculiar odor and a bland taste. G. Insoluble in water; soluble in 5 parts absolute alcohol, in 1.5 parts ether. d. Linseed oil, treated with nitrous acid, does not yield elaidin. Mixed with concentrated sulphuric acid, as directed under Drying and Non-drying Oils, Distinctions between, p. 282, very high numbers are obtained. Treated with iodine, large ab- sorption capacity is found (pp. 258 and 259). For oxygen-ab- sorption see Drying Oils, etc., p. 283. , /. For Separation and Valuation of Linseed oil, see Dry- ing Oils, p. 281, and Linoleic Acid, p. 249. g. Linseed oil is adulterated with cotton-seed oil, mineral 1 Schaedler: "Technologic der Fette und Oele," 1883, p. 494. Benedikt, " Analyse der Fette," 1886, p. 215. OLIVE OIL. 285 oils, rosin oil, niger-seed oil, rape-seed oil, hemp-seed oil, and fish oils. Mustard, rape, and hemp seeds are gathered with flax-seed. Specific gravity of mineral oils is lighter than of linseed oil, usu- ally from 0.880 to 0.905 ; while resin oil is heavier, 0.96 to 0.99. Non- drying oils are indicated by the elaidin test, by not generat- ing the full quota of heat with sulphuric acid, by not absorbing the proper amount of oxygen, and by lower iodine numbers, ac- cording to directions given under Drying Oils, p. 281. Presence of hydrocarbon or mineral oils is shown by their non-saponifi ca- tion, sometimes revealed by fluorescence, and sometimes by distil- lation, as specified under Separation of Mineral Oils from Fat Oils, p. 274. Examination for Rosin Oil is directed under the latter, p. 281. Boiled Limeed Oil is prepared by exposure to a high tempe- rature, by which it undergoes oxidation and acquires increased readiness for oxidation. Dryers are added, also, in the " boiling,"' to promote oxidation by the atmosphere. Manganese and lead oxide, used as dryers, leave traces of these metals in the oil, so that they may be detected in the ash. Boiled linseed oil is frequently adulterated with a very little rosin and with rosin oil. OLIVE OIL. The fixed oil expressed from the fruit of Olea europoei. Olivenol, Baumol. " Sweet oil." Among the best are Provence oil and Florence oil. Lucca and Gallipoli oils are good brands. Sicily oil is seldom of best quality. Olive oil is adulterated and substituted by cotton-seed oil, rape oil, poppy oil, sesame oil, peanut oil. a. A pale yellow, or light greenish-yellow, oily liquid, of sp. gr. 0.915 to 0.918 (U.-S. Ph. and Ph. Germ.) At 15 C. r best 0.9178 ; Gallipoli, 0.9196 (CLARK) ; 0.914 to 0.917 (ALLEN). At 18 C., yellow-green 0.9144, dark 0.9199 (STILTJRELL). Spe- cific gravity of the fat acids, at 100 C., 0.8429-0.8444 (ARCH- BUTT). Congealing point, turbid at 2 C , solid at 6 C. Of the fat acids, congealing point 21.2 C., melting point 26 C. (HiiBL) ; congealing point not under 22 C., melting "point 26.5 to 28.5 C. (BACH). b. Of a nutty, oleaginous, and faintly acrid taste, and nearly without odor. c. Sparingly soluble in alcohol, readily soluble in ether. g. Tests for purity." If 1 part of olive oil be agitated in a test-tube with 2 parts of a cold mixture prepared from equal 286 FA TS AND OILS. volumes of strong sulphuric acid and of nitric acid of sp. gr. 1.185, and the mixture be set aside for half an hour, the super- natent, oily layer should not have a darker tint than yellowish (a dark color indicating the presence of other fixed oils). If 12 parts of the oil be shaken frequently during two hours with 1 part of a freshly-prepared solution of 6 grams of mercury in 7.5 grams of nitric acid (sp. gr. 1.40), a perfectly solid mass of a pale straw color should result ; and if 1 gram of the oil be shaken for a few seconds with 1 gram of a cold mixture of sulphuric acid (sp. gr. 1.830) and nitric acid (sp. gr. 1.250), and 1 gram of di sulphide of carbon, no green or red layer should separate on standing. If 5 drops of the oil are let fall upon a thin layer of sulphuric acid in a flat-bottomed capsule, no brown-red or dark zone should be developed within three minutes at the line of contact of the two liquids (absence of appreciable quantities of other fixed oils of similar properties)." U. S. Ph. " At about 10 C. it begins to grow turbid by crystallization, at C. acquires a salve-like thickness. When 5 grams of the oil are shaken with 15 drops of nitric acid of sp. gr. 1.38, neither the acid nor masses swimming upon it should take a red color. Fifteen parts of olive oil which have been strongly shaken with a mixture of 2 parts water and 3 parts of fuming nitric acid should form a whitish mass, not red nor brown, separating in 1 or 2 hours in a solid mass, while the liquid is scarcely colored." Ph. Germ. " Pale yellow or greenish-yellow, with a very faint, agreeable odor, and a bland, oleaginous taste ; congeals partially at about 36 F. (2.2 C.) " Br. Ph. Specific gravity of mixtures of Olive oil with stated percentages of other oils, at 15 C. (SOUCHEKE, 1881, using Lefebre's Oleometer) : Name of the oil. Sp. gr. of the oil admixed. 10 per ct. 20perct. SOperct. 40 per ct. SQper ct. Olive 0.9153 Colza. 09142 0.91519 91508 91497 0.91486 0.91475 Sesame Cotton-seed. . Walnut 0.9225 0.9230 0.9170 0.91602 0.91607 0.91547 0.91674 0.91684 0.91564 0.91741 0.91761 0.91581 0.91818 0.91838 0.9159S 0.91890 0.91915 0.91615 TURKEY-RED OIL. COTTON-SEED OIL. 287 Congealing and Melting points of Fat Acids of Olive oil with stated percentages of fat acids of other oils (BACH, 1 1883) : Fat acids from Congealing at Melting at Pure olive oil Above 22 C. 26,5-28.5 C. Olive oil with 20$ cotton-seed oil 28 31.5 Olive oil with 20$ sunflower- 18 24 Olive oil with 33$ rape-seed oil 16 5 23 5 Cotton-seed oil, alone 35.0 38.0 Castor oil, alone 2.0 13 TURKEY-RED OIL. A thoroughly non-drying oil suitable for technical use in dyeing cotton turkey-red. Grades of olive oil have generally been used. Partly unripe olives, macerated in boiling water before being pressed, yield an oil rich in extractive matter and favorable for this use. In the elaidin test a solid and firm elaidin, of white color, should be obtained. OLIVE-KERNEL OIL. From the kernel or nut of the olive, by pressure, or extraction with carbon disulphide. Distinguished from olive oil by its dark greenish-brown color and a quite free solubility in alcohol or glacial acetic acid. COTTON-SEED OIL.* Baumwollensamenol or Baumwollenol. Huile de Coton. Oleum gossypii seminis. A fixed oil ex- pressed from the seed of species of Gossypium. The crude oil contains as much as 15 pounds of color substance per ton (LONG- MORE). The color substance, termed gossypin, is soluble in alka- lies, and from alkaline solution precipitated by acids. Treatment with soda lye of five or six per cent, at 60 F. is adopted in puri- fication of the oil, only a small part of which saponifies. The soapy mixture containing the color, when digested with strong soda lye and then neutralized with sulphuric acid, yields a pre- cipitate of the gossypin. 1 Chemiker-Zeitunq, 7, 356; ZeitscTi. anal. Chem., 23, 259; Am. Jour. Phar., 55, 354. 2 Production, Uses, and Properties, C S. Munroe, 1885: Am. Chem. Review, 5, 26. Purification, J. Longmore, 1886: Jour. Soc. Chem. Industry. 238 FA TS AND OILS. a. The crude oil is a thick, brownish, turbid liquid, which deposits a slimy residue. The clarified oil is clear orange yel- low ; better purified grades light yellow. Fully refined cotton- seed oil is of a very pale straw color. Sp. gr., at 15 C., 0.922-0.930 (ALLEN); 0.9228 (YALENTA); at 17 C., 0.923 (SCHEIBE); at 18 C., crude oil 0.9221, refined oil 0.9230, white oil 0.9288 (STILURELL). Sp. gr. of the fat acids at 100 C., 0.849 (ARCHBUTT). Congeals to deposit stearin at 12 C. ; solidifies fully at to 1 C. The fat acids congeal at 30.5 C. (HiiBL), at 35.0 C. (BACH), at 35.5 C. (YALENTA); melt at 35.2 C. (ALLEN) ; begin to melt at 39-40 C., melt wholly at 42-43 C. (BENSEMAN). 1. The well-refined oil has only a slight earthy odor, and a bland, perceptibly nutty taste. c. Solubility in glacial acetic acid, according to Yalenta, is stated at p. 273, and furnishes a distinction from olive oil. d. Stirred with potassium hydrate solution, crude cotton- seed oil colors blue in the upper layer, becoming violet on expo- sure to the air. The same colors are developed on saponifying with alcoholic potassa, but are -hardly made -perceptible with the most fully refined oil. When a drop of sulphuric acid is added to a larger quantity of unrefined oil, bright red to brown colora- tion is produced. The test is better made with near equal quan- tities of oil and sulphuric acid of sp.gr. 1.76, gently warming the mixture after observing the first effect. The refined oil re- sponds very slightly to this test. In the elaidin test cotton-seed oil gives elaidin, with reddish-yellow to brownish-yellow colors, these tints being obtained also with nitric acid of sp. gr. 1.42 added in equal volume. Silver nitrate in ether-alcoholic solu- tion is gradually reduced, with dark colors, but t.iis is in a de- gree common to seed oils and olive oil. BECHI (1885) uses a \% solution of silver nitrate in strong alcohol, adding 5 c.c. of this solution to a mixture of 25 c.c. alcohol and 5 c.c. of the oil, and warming to 84 C., when olive oil, he states, does not color if cotton- seed oil be absent. Cotton-seed oil contains about 1.64$ of non- saponifiable matter (ALLEN and THOMPSON, RODIGER). By full saponification and extraction of the dry soap with petroleum benzin (p. 275) a distinction from olive oil is obtained. Cotton-seed oil is a very feebly drying oil. For its identifi- cation, and distinction from olive oil, by this property, tests are made by oxygen-absorption (p. 283), warming effect of sulphuric acid (p. 282), and the iodine numbers (p. 258). Its separate fat REE fy, COTTONSEED STEARIN. CASTOR $$2$$ acids, in the oxygen-absorption test, unlike the entire oil, with wholly non-drying oik, The high melting and congealing points of the fat acids of cotton-seed oil distinguish it from most other similar oils (a, and pp. 265, 269). Distinctions between cotton-seed oil and olive oil are further given under the head of the latter, p. 285. The saponification numbers of olive oil and cotton-seed oil are too near each other .to furnish a means of distinction. COTTON SEED STEARIN. Baumwollenstearin. Vegetable Mar- garin. Vegetable Stearin. The residue of cold-pressed cotton- seed oil. A sample examined by MUTER had sp. gr. 0.9.115-0.912 at 37.7 C. (100 F.), and gave 95.5$ insoluble fat acids, perfectly soluble in hot absolute alcohol as well as in ether.' The melting point was 32.2 C., the melted liquid having a yellow color and odor of cotton-seed oil. It concealed again at about 1 C. A sample examined by Mayer melted at 39 C. CASTOR OIL. Oleum Ricimv Rieinusol. IluiJe de ricin, de castor. A fixed oil expressed from the seed^of the Ricinus communis. See Ricinoleic Acid, of which it is in chief paft the . glyceride, p. 248. Eicinoleiri is C 3 H 5 (C 18 H 33 O 3 ) 3 = 931.': a. " Ail -almost colorless, transparent, viscid liquid ; of sp. gr,, 0.950-^0.^70." U. S. Ph. Sp. gr. at 15 C., 0.9613-0.9736 (VALENTA)"; ;lfta,8.C., 0.9667 (ST^LURELL) ; at 23 C., 0.9B4 (DIETE$ICH). Conceals, at 10 to -18 C. Fat acids congeal at 3 C, ; .melt at 13 C. (HiiBLJ. " When cooled it becomes thicker, generally depositing white granules, and at about 18 C. (0.4 1\) it congeals -to, a yellowish mass." U. S. Ph. &. "Of a blarixj-f "afterwards slightly acrid and 'generally of- fensive taste, and .a faint, wM odor." IT. S. Ph. 0." Soluble inlin equal weight of alcohol [0.820 at 15 6 C.] and in all proportions of absolute alcohol or glacial acetic acid." U. S. Ph. At 15 p. in 2 parts 90$,and in 4 parts 84$ alcohol. Not soluble in petroleum benzin, kerosene, or paraffin oil, but dissolves about one and a half volumes of kero- sene or paraffin oil. The solubility in alcohol is much varied by temperature. d. Castor oil is to a very slight extent a drying oil. Expo- sure to air causes it to become perceptibly thicker. In the heat- ing effect of sulphuric acid (p. 282), and in the iodine number of 290 FA TS AND OILS. the oil or its acid (p. 258), castor oil stands not far from olive oil. It gives the elaidin reaction. Its saponification number is comparatively low (p. 257). g. Impurities and substitutions. The solubilities in alco- hol and in glacial acetic acid, quoted under c from the U. S. Ph., furnish a generally satisfactory means of revealing impurities. The absorption of a little petroleum benzin has been used by llager for detection of adulterations as follows : One volume of the oil is agitated in a test-tube with 2 volumes of the benzin, and set aside. The lower layer should be increased to from 1.6 to 1.75 of the original volume of the castor oil. In case of adul- teration the lower layer will be proportionally deficient. Under direction of the New York State Board of Health, in 1881, Prof. G. C. Caldwell 1 examined 16 samples, of which 9 were considered adulterated, 1 w r ith sesame oil, 4 with cotton-seed oil, 2 with peanut oil, and 2 with cotton-seed oil or peanut oil or both. While giving a caution against dependence upon single tests (not thoroughly subjected to control analyses), Prof. Cald- well advises the legal adoption of test limits. LAED. Adeps. Schweinschmalz. Graisse de pore. " The prepared internal fat of the abdomen of Sus scrofa, purified by washing with water, melting, and straining." a. A soft, white, unctuous solid, of sp. gr. about 0.938 (U. S. Ph.) at 15 C. ; at 100 C. (water at 15 = 1) 0.861 (Ko- NIGS). Melts at or near 35 C. (U. S. Ph.), 42-48 C. (KdNiGs). At 26 C. melted lard begins to congeal, and during congelation the temperature rises to 30 C. (SCHAEDLER). The fat acids melt at 35 C., and congeal again at 34 C. (MAYER). When rancid, lard acquires a yellowish color. . Lard when fresh and good has a faint odor free from rancidity, a bland taste, and a neutral reaction. In the air it soon becomes rancid and of an acid reaction. c. It is entirely soluble in ether, petroleum benzin, and disulphide of carbon. ^ ee first-named is found ready formed in opium. These 'C. R. A. WRIGHT and co-workers, 1872-1877: Proc. Roy. Soc.. 20; Jour. Chem. Soc., 25 1032; on narcotine and narceine, 29, 461; 28, 573; 32, 525; on morphine and codeine, 25, 150, 504. 0. HESSE, 1872: Ann. Chem. Phar., Suppl. Bd., 8, 261; Jour. Chem. Soc., 25, 721; 1884: Liebig's Amialen, 222, 203; Jour. Chem. Soc., 46. 613. E.v. GERICHTEN, 1881-83: Ber.d. chem. Ges., 13, 1635; 14, 310: 15, 2179; Jour. Chem. &>c., 40, 110, 445; 44, 221. GRI- MAUX, 1881-83: Ann. Chim. Phys. [5] 27, 273; Jour. Chem. Soc., 44, 358. CHASTAING, 1881: Compt. rend., 94, 44: Jour. Chem. Soc., 42, 413. A list of opium alkaloids, with a few derivatives, arranged in order of the number of car- bon atoms, is given in the Pharmacographia of F. & H., 2d ed., p. 59. 362 OPIUM ALKALOIDS. three bodies are related in structure, as benzene derivatives, as follows : ( (OCH 3 ) 2 ( (OCH 3 ) 2 ( (OCH 3 ) 2 C 6 H 2 \ CO . O C 6 H 2 \ CO ,H C 6 H \ CO 2 H ( CH 2 ( COI1 ~ ( C0 2 H Meconin. Opianic acid. Hemepic acid. Hesse (1872) presented a practical division of the opium al- kaloids into groups, according to their deportment with pure sulphuric acid, as follows : 1. a. Dirty dark-green. Morphine, pseudomorphine, codeine. J Dirty red- violet. Laudanine, codamine, laudanosine. 2. Dirty green to brown-green. Thebaine [?], cryptopine, pro- topine. 3. a. Dark- violet. Papaverine. b. Black-brown to dark-brown. Narceine, lanthopine. 4. Dirty red-violet (of shade different from that of 1 &). Kar- cotine, hydrocotarnine. MORPHINE. C 17 H 19 NO 3 1 = 285. Crystallized, C 17 H 19 NO 3 . H 2 O = 303. (For structure see p. 361.) In opium, as sulphate and meconate. In all parts of the Papaver somniferum, more particularly in the leaves, stems, and seeds just before maturity. In other species of Papaver. Of dried opium crystallized mor- phine forms from 3 to 20 per cent. : by the U. S'. Ph. (1880) 12 to 16, average 14, per cent. ; by the Br. Ph. (1885) 10 per cent, (or 9.5 to 10.5 per cent.); by the Ph. Germ. (1882) at least 10 per cent. ; by the Ph. Fran. (1884) 10 to 12 per cent. ; these pharmacopoeial standards being further defined according to methods of assay given in each. The U. S. Ph. of 1870 specified for dried opium at least 10 per cent, morphine; the U. S. Ph. of 1860, for opium not dried, at least 7 per cent, morphine. Since 1848 the U. S. customs' service has required of opium imported at least 9 per cent, of morphine on the moist basis equal to 11J-12 per cent, on a dry basis. And so well has the standard of importation been maintained that, for years before the pharmacopoeia of 1880 came into effect, very little opium in reputable hands in this country contained less than about 12 per cent, of morphine on a dry basis. In 1882, before the present pharmacopoeia was issued, Dr. Squibb reported from 230 cases of opium an average of 12.45 per cent, in the dry state, and from * ' LAURENT, 1847: Ann. Cfiim. Phys. [31 10, 361. WRIGHT, 1877, C, 4 H M N,0., MORPHINE. 363 191 cases an average equal to 12.35 per cent, in the dry state ; and in the same year Mr. C. W. Parsons reported the assay of 21 Turk- ish opiums with an average of 15.2 per cent, of morphine in the dried opium. In fact, although opium was much stronger than the national pharmacopoeia required it to be, the pharmacopoeia gave no authority for diluting it. Opium, not powdered, could be diluted only by the grossest sophistication. Additions to powdered opium, if made by reputable persons, were made in accordance with an assay and then declared in the brand of the article as containing a specified percentage of morphine. If made by persons without repute or scruple, the limit of the phar- macopoeia would be little regarded. 1 Morphine is recognized under the microscope by its form as free alkaloid crystallizing from solution (a) ; is identified by chemical tests with ferric chloride, sulphuric and nitric acids, Froehde's reagent, phosphomolybdate solution, etc. (d, p. 365) ; is separated by action of amyl alcohol on alkali solutions, and by other means (e) ; and from viscera, in cases of suspected poisoning, and with reference to the recovery of Meconic acid, as directed. Morphine is usually estimated gravimetrically as free alkaloid (f) ; sometimes volumetrically by Mayer's solution (p. 43), or coiorometrically by iodic acid. The estimation of morphine in opium is indexed under f. The yield of mor- phine in opiums is stated on p. 362. The tests of purity of the alkaloid and its salts are given under g. a. Morphine crystallizes, with one molecule of water, in short, translucent, hexihedral prisms of the rhombic (trimetric) system, or in white, lustrous needles. If a few drops of a warm saturated aqueous solution, or a dilute alcoholic solution, be al- lowed to evaporate spontaneously on a glass slide, characteristic crystalline forms are obtained, to be recognized in analysis by comparison with forms from a known portion of morphine treated in the same way. Too rapid evaporation gives an amor- phous residue. Morphine is permanent in the air and below 100 C., and becomes anhydrous at 120 C. (248 F.), losing 5.94 per cent, of the weight of the crystals. According to TAUSCH (1880) the water is expelled at 100 C., though slowly. At 150 C., in the "subliming cell" (BLYTH, 1878), morphine "clouds the upper disc with nebulae ; the nebulae are resolved by high mag- 1 Further, an article by the author " On the Strength of Opium and its Preparations in this Country, as compared with the standards of the Pharma- copoeias of 1870 and 1880," 1883: Proc. Mich. State Pharm., i, 48. 364 OPIUM ALKALOIDS. nifying powers into minute dots ; these dots gradually get coarser, and are generally converted into crystals at 188 G. ; the alkaloid browns at or about 200 C." Heated on platinum foil the crystals melt, then char, and slowly burn completely away. The crystals are of sp. gr. 1.317-1.326 (SCHRODER, 1880). Morphine solutions are levorotatory : [a] r = 88.04 (Bou- CHARDAT; HESSE, 1875). Crystallization and heat reactions of Morphine Salts. The sulphate, (C 1 7P1 19 NO 3 ) 2 H 2 SO 4 .5H 2 O = 758, crystallizes easily in colorless, feathery needles of silky lustre, permanent in the air, losing its water of crystallization '(11.87$) at 130 C. (at 100 C., Ph. Germ.) The hydrochloride, C 17 H 19 NO 3 HC1 . 3H 2 O = 375.4, forms colorless, feathery needles of silky lustre, or minute white, cubical crystals, permanent in the air, parting with the water (14.38$) at 100 C. (TAUSCH, 1880, Ph. Germ.), at 130 C. (FLUCKIGER, " Phar. Chem.") Morphine acetate holds 3H 2 O, with the molec. weight 399, in a white or faintly yellowish- white, crystalline or amorphous powder, slowly losing acetous vapor in the air. Morphine hydrohromide, with 2H 2 O, crys- tallizes in needles, becoming anhydrous at 100 C. (SCHMIDT, 1877). Morphine hydriodide, 2H 2 O, forms needles and rosettes, and parts with its water at 100 C. (BAUER, 1874 ; SCHMIDT, 1877). ~b. Morphine is without odor, and of a bitter taste, more promptly obtained from its soluble salts. It is narcotic, hyp- notic, causing contraction of the pupils, and on animals often producing convulsions and paralysis. The fatal dose is not at all uniform for different species of animals of the same size. The alkaloid undergoes change, in part, while passing through the animal body. 1 Further respecting its deposition in the vari- ous organs and recovery therefrom by analysis, see statements under e. c. Solubilities of the free alkaloid. Morphine, crystallized, is very slightly soluble in cold water (1 to 5000-10000, CHAS- TAING, 1882); soluble in 500 parts of boiling water ; in about 100 parts of ordinary alcohol at 15 C., or 36 parts of boiling ordinary alcohol, or 13 parts of boiling absolute alcohol. The saturated solution in cold absolute alcohol contains one part in 60, and is not precipitated by adding water (Fliickiger's " Phar. Chem.") In different conditions, different quantities of solvent are required, as follows the " nascent" condition being that of liberation from 'Husemann's "Pflanzenstoffe," 1S83, p. 706 ELIASSOR. 1884. MORPHINE. 365 salt in aqueous solution: the ether, chloroform, and amyl alcohol, water-washed : 1 Ether. Chloro- form. Amyl. Ale. Benzene. Crystallized 6148 4379 91 8930 Amorphous powder 2112 1977 Nascent state. . . 1062 861 91 1997 Morphine is not dissolved by petroleum ether. The solvents above-named, immiscible with water, do not take morphine from acidified solutions. Morphine is dissolved somewhat freely by aqueous fixed alkalies, and by 117 parts of water of ammonia of sp. gr. 0.97. It is a decided base, and neutralizes strong acids. Solubilities of Morphine Salts. Morphine sulphate is solu- ble in 23 parts of water at 15.6 C. (DoTT, 1882) ; in an average of 21 parts of water at 15 C. (COBLENTZ, 1882) ; in 24 parts water at 15 C. (U. S. Ph.) ; in 0.75 part boiling water (IT. S. Ph.); in 702 parts of alcohol at 15 C., or 144 parts of boiling alcohol (U. S. Ph.) Morphine hydrochloride is soluble in 24 parts of water at 15.6 C. (DoTT, 1882), or 0.5 part of boiling water; in 63 parts of alcohol at 15 C., or 31 parts of boiling alcohol ; not soluble in ether (U. S. Ph.) Morphine acetate is soluble in 2J parts of water at 15. 6 C. (Doir, method of digestion, 1882); when freshly prepared in 12 parts of water at 15 C., or 68 parts of al- cohol at same temperature (U. S. Ph.) ; in 60 parts of chloroform (U. S. Ph.) It is decomposed by boiling alcohol, so that, on adding water, free morphine is precipitated (Fliickiger, " Phar. Chem.") Morphine tartrate (normal, 3H 2 O) is soluble in 9.7 parts of water at 15.6 C. (DoTT, 1882) ; morphine meconate (5II 2 O), in 33.9 parts water at 15.6 C. (the same). The hydro- bromide is soluble, the hydriodide slightly soluble, in cold water. d. The color tests for morphine, when the alkaloid is per- fectly separated, are not extremely delicate, as compared with tests for other alkaloids, and are more than usually liable to error from admixture of non-alkaloidal matters. The test with nitric and sulphuric acids ranks first as a means of distinction. Sulphuric acid itself (strictly free from 'The author. 1875: Am. Chem, 6, 84; Jour. Chem. Soc., 29, 405. 366 OPIUM ALKALOIDS. nitric acid) does not color dry morphine (free from narcotine, papaverine, p. 359), or causes only the slightest reddish colora- tion, unless heat be applied. On the water-bath some shade of purple to brown occurs, later deepening to a brown. Sulphuric acid and cane sugar color morphine purple-red. Minute traces of nitric acid cause a violet to purple color in the cold or on slight warming, and this application of morphine constitutes a very delicate though not distinctive test for nitric acid as an impurity in sulphuric acid. Also the sulphuric acid alone is a delicate test for certain other opium alkaloids as impurities in morphine. Nitric acid alone colors morphine red to orange or reddish-yellow the coloration not being intense. Concentrated sulphuric acid with a very little nitric acid gives a violet color. ERDMANN (1861) employed sulphuric acid with intermixture of one per cent, of nitric acid, sp. gr. 1.25 adding 8 to 20 drops to 1 or 2 milligrams of alkaloidal solid for a violet color. HUSEMANN ' treated the solid alkaloidal matter with a little sulphuric acid, heated the solution above 100 C., but not as high as 150 C., and then touched with a drop or two of nitric acid of sp. gr. 1.2, for a dark violet color. BARFOED (1881) dissolves the solid alkaloid in concentrated sulphuric acid, two drops for each milligram, and heats above 100 C. for a second or two, and then adds, to a thin layer on the porcelain surface, a minute fragment of potassium nitrate, a red color giving evidence of morphine, a violet-red obtained with a good quantity, and a rose-red when but a little is present. Instead of nitric acid, other oxidizing agents, potassium chlorate, or chlorine water may be used. Of the forms of the test above mentioned the last given one is preferred. But the test without heat can be recommended as follows : To a quantity not over a few milligrams of the dry residue to be tested, on a white porcelain surface, add a drop of pure sul- phuric acid, and rub with a narrow glass rod for a few minutes, not spreading the acid more than is unavoidable. The point of the glass rod is now touched to nitric acid of sp. gr. 1.42, and drawn across the dissolved residue. A red color, violet if in- tense, rose-red if less distinct, and soon paling, is the evidence of morphine. The limit of quantity revealed with a good color by this form of the test is about 0.0005 gram of morphine. 2 Huse- inann gave, as the extreme limit, with heat, 0.00001 gram. 1 1863-1876: Arch. d. Phar., 206, 231: Zeitsch. anal. Chem., 15, 103. 2 "Control Analyses and Limits of Recovery," by the author, 1885: Proc. Am. Assoc. Advanc. Sci., 34, 111 ; Chem. News, 53, 78 : et seq. Respecting the color reactions of nitric acid, see further a note by the author, 1876: Am. Jnur. Phar., 48, 62. . MORPHINE. 367 Without heat there is less danger of error due to extraneous matters. Froehde's reagent 0.001 gram of molybdic acid or mo- lybdate of soda freshly dissolved by aid of heat in 1 c.c. of con- centrated sulphuric acid (Dragendorff), and the solution cooled gives a bright color reaction for morphine, quite delicate, but not very distinctive. A drop of the reagent is applied to the dry alkaloidal residue, not over a few milligrams, on a white porce- lain surface. Morphine gives a blue color, simply that of a cer- tain lower oxide of molybdenum, obtained by deoxidation violet- blue when pale, and changing, through shades of greenish-blue, finally to dark blue. 1 Kauzmann placed the limit of quantity of morphine responding to this test at 0.00005 gram ; Wormley, for blue color, at 0.00007 gram. Unless other reducing agents can be excluded it is unsafe to depend upon this test alone as evi- dence for morphine. The iodic acid test is another application of the reducing power of morphine, which promptly liberates iodine from iodic acid, and in presence of starch gives the blue color of iodized starch. It is generally applied to the aqueous solution of a salt of morphine, a single drop of which is enough. DUPEE (1863) directs to evaporate the morphine with a drop of starch solution to dryness, and when cold to moisten with a solution of iodic acid. WOEMLEY states that 0.00007 gram of the alkaloid will give a blue color. With very dilute solutions in considerable quantities, liberated iodine may be sought for by shaking, in a test-tube, with carbon disulphide or chloroform. The reaction has been used for a volumetric method of estimation. This test, carefully applied, is scarcely exceeded in delicacy by any other, and it furnishes a confirmation to affirmative results by other tests, but the presence of morphine should never be declared upon the evidence of this test alone. The chemist should clearly understand that a multitude of reducing agents, inorganic and organic, will liberate iodine from iodic acid. The two tests last above given depend upon the reducing power of morphine. Compared with other non-volatile natural alkaloids, it is a strong deoxidizing agent. To give these two tests any value, non-alkaloidal reducing agents, such as tissue substances, must be strictly removed. In any doubt as to their removal, a control analysis may be instituted, in which like tis- 'FROEHDE, 1866; ALM&N, 1868; KAUZMANN, 1869; NEUBAUER, 1870; DRA- GENDORFF, 1872. " Note on Froehde's Reagent as a test for Morphia," the au- thor, 1876: Am. Jour. Phar., 48, 59. WORMLEY directs a 3 per cent, solution of molybdic acid in sulphuric acid; BUCKINGHAM, a 7 per cent, solution. 368 OPIUM ALKALOIDS. sues or other matters are treated with the same solvents, in the same conditions, and the product subjected to these final color tests, in comparison with the residues liable to contain mor- phine. The capacity of morphine for combination with oxygen renders the alkaloid somewhat instable, though in other respects it is a quite stable alkaloid. Among the oxidation products known are Oxymorphine, C 17 H 19 NO 4 (perhaps Pseudomorphine, HESSE), and Oxydimorphine, C 34 H 36 N 2 O 6 , formed by action of silver nitrite, potassium permanganate, or ferricyanide ; and a body of the composition C 10 H 9 NO 9 (CHASTAING, 1882). By hot sul- phuric acid, at 150-160 C., " Sulphomorphid," C 34 H 36 ]N" 2 O 8 S, is formed, a body probably closely related to Apomorphine sulphate. As obtained it is a white, amorphous mass. Nitric acid converts morphine into a resinous body, which, treated with potash, yields methylamine (ANDERSON). Gold and silver are reduced from so- lutions of their salts by morphine. Another application of the reducing power of morphine has been made in a test by a drop of ferric chloride followed by a drop of very dilute solution of potassium ferricyanide, when' a blue color results from the formation of ferrous salt. It is said that a solution of morphine salt in 10000 parts of water gives a blue color by this operation. According to WORMLEY, narcotine and brucine give this reduction. The reaction is also a test for Ptomaines (which see). LONG (1878 ') observed a reaction of mor- phine with ammonio-cupric sulphate, giving a green color, per- haps due to reduction. When morphine is treated with concen- trated sulphuric acid (p. 365), and then with potassium chromate, a green color is obtained, due to the reduction of the chromium. Therefore, in the fading purple test for strychnine, morphine, if present in sufficient quantity, gives a green color (not fading). Ferric chloride, as a normal salt, with no free hydrochloric acid, in solution of ordinary reagent strength, gives a blue color with morphine or its salts. The solid residue, while cold, on a white porcelain surface, is moistened with a drop of the reagent, or by touching with a narrow glass rod wet with the reagent. According to WORMLEY, a good deep color can be obtained with 0.0007 gram (0.001 grain) of alkaloid in solid residue. A solu- tion of morphine must be as concentrated as 1 : 600 in order to give the color. Less delicate than the tests previously given, this test is quite as characteristic as any other." It is necessary, 1 Chem. News, 38; Am. Jour. Phar., 50, 490. 2 A comparison of the tests by iodic acid. Froehde's reagent, and ferric chloride, applied to morphine, grape-juice, orange-juice, and saliva, was reported by I). BROWN, 1878: Phar. Jour. Trans. [3] 8, 70; Proc. Am.Pharm., 27, 485. MORPHINE. 369 however, to exclude various organic acids of aromatic composi- tion, including the tannins, phenols, salicylic acid, etc., as enu- merated under Phenol, d 1 According to SELMI (1876) certain cadaver alkaloids give the blue color to ferric salts, as well as- reduce iodic acid. But these cadaveric alkaloids did not give the violet color obtained by morphine on treatment with a solution of lead dioxide in glacial acetic acid, evaporating at a gentle heat. The general qualitative reagents for alkaloids all respond to morphine. Phosphomolybdate gives a very nearly complete precipitate of a yellowish -white color, dissolving in ammonia with a blue color. Potassium mercuric iodide, or Mayer's solution, gives a less perfect precipitate, not appearing at all in solutions of 1 to 4000. The precipitate approximates to the com- position (Ci 7 H 19 lS T O 3 HI) 4 (HgI 2 ) 3 . 5 ' Iodine in iodide of potas- sium solution gives a reddish-brown precipitate, immediately visible in one drop of a solution of the alkaloid in 10000 parts of water (WORMLEY) ; under the microscope in a 1 to 100000 solution (SELMI, 1876). On standing, reddish-brown crystals form. The precipitate dissolves in alcohol, in alkalies, slowly in acetic acid. Its distinction, under the microscope, from other opium alkaloids, is given by SELMI, 1876. Potassium iodide gives a formation of needle-shaped crystals, somewhat character- istic, obtained only in quite concentrated solutions. Tannic acid and picric acid give precipitates in solutions not very dilute. Alkali carbonates and bicarbonates precipitate morphine, not soluble in excess of the precipitant. Alkali hydrates give a crystalline precipitate, dissolved by excess of fixed alkalies, and by lime solution, sparingly soluble in excess of ammonia. Crystals of free morphine, obtained by precipitation with a little excess of ammonia, or by spontaneous evaporation of a dilute alcoholic or warm aqueous solution, examined under the microscope (in comparison with known morphine under like treatment), give valuable confirmatory evidence of the identity of the alkaloid (p. 363). e. Separations. Aqueous solutions of morphine are con- centrated on the water-bath without marked loss, but if the concentration ^ require long time, or if the solution be complex, in a quantitative separation, it is better to evaporate under dimin- ished pressure at temperature not above 60 to 75 C. From 1 CHASTAING (1881) claims, from the chemical proportions in which mor- phine unites with fixed alkalies, and other considerations, that this alkaloid is in fact a phenol. 2 The author, 1880: Am. Chem. Jour., 2, 294. 370 OPIUM ALKALOIDS. substances insoluble in acidified water or alcohol these solvents remove morphine in its salts, and hot alcohol may be used to dis- solve out the free alkaloid. Of solvents not miscible with water, amyl alcohol is the most satisfactory for morphine. The acidified aqueous solution may be purified, or freed from other alkaloids, by shaking out with benzene, or chloroform, or ether, and finally with amyl alcohol itself. Then the liquid is made alkaline by adding ammonia, and exhausted of morphine by repeated por- tions of amyl alcohol, or by a continuous liquid-extraction appa- ratus supplied with this solvent. It is to be remembered that arnyl alcohol carries with it a little of the aqueous solution, so that the amyl alcohol solution requires water- washing, and a little waste occurs. In separation from the tissues and contents of the stomach, or other matters, in analysis for poisons} the solids are finely divided, in a good-sized evaporating-dish, by playing upon the material with a pair of bright, sharp shears. The divided ma- terial may then be treated as directed under Atropine, p. 354, substituting amyl alcohol for chloroform as a solvent of morphine. Tartaric acid may be used for acidulation instead of sulphuric, to favor the rejection of ptomaines (GUARESCHI and Mosso, 1883). If it be analysis for opium constituents, it is to be understood that Narcotine is dissolved sparingly by amyl alcohol applied to acidulous solutions, also sparingly dissolved by benzene applied to alkaline solutions, morphine remaining undissolved in both these cases. Unless morphine be found in more than traces, narcotine is not likely to be recovered with identification. Evidence of opium, in distinction from morphine alone, is more confidently sought through tests for Meconic acid. This acid may be separated from the aqueous liquid, in the course for morphine, if acetic acid be added instead of tartaric acid, for acidulation. The filtered aqueous liquid is treated with lead acetate solution, just sufficient to complete a precipitate formed, and filtered. The filtrate is treated with enough hydrogen sulphide gas to throw down all the lead, then filtered, and the filtrate treated in the course of analysis for the morphine The precipitate first formed on adding the lead acetate is washed on the filter with a little water, carried through the filter-point with a thin jet of water, the lead meconate decomposed by hydrogen sulphide gas, the mixture filtered, the filtrate evaporated, the 1 Toxicology: Taylor on Poisons; Blyth's Poisons; Wharton and Stille. vol. 2, 1884; Dragendorff's "Ermittelung von Giften" and " Organ ischer Gifte"; Worraley's " Microchemistry of Poisons," 3d edition, 1885. STRUVE, 1873: Zeitsch. anal. Chem., 12, 168. MORPHINE. 371 residue taken up with strong alcohol, this solution filtered and evaporated, the residue taken up with warm water, and tested, with ferric chloride and other reagents, for Meconic acid (which see). The residue from .the careful final evaporation of the aniyl alcohol solution of morphine which may be divided in several dishes for the tests and for weight as directed in analysis for atropine is examined for its deportment in tests by (1) sulphuric and nitric acids, (2) sulphuric and molybdic acids, (3) ferric chloride, (4) iodic acid, and (5) with phosphomolybdate, as direct- ed for each under d. Also, (6) a drop of the warm aqueous, or dilute alcoholic, solution is allowed to evaporate very slowly, under the microscope, for crystals of free morphine, to be recog- nized as stated under a. Other tests may be added. The amyl alcohol used should be examined by evaporating a quantity as large as that used in the analysis, and if any fixed residue be obtained, or if a solution of a supposed residue in acidulated water give reactions with general reagents for alka- loids, then the portion of this solvent to be used must be redis- tilled, after adding a little tartaric acid. To decide any question as to results, a control analysis should be carried in a parallel operation upon tissue material as nearly as possible the same as that under examination for poisons. If the tissue material taken be very troublesome, or if the operator prefer, the first solution from the tissues may be an alcoholic acidulous solution, and the residue from the evaporation of this solution may be taken up by water (and a very little acid). If acetic acid be used, care must be taken that acid reaction with litmus be main- tained. It is better that the temperature of evaporations be kept below 80 C., and that concentrations be hastened by a re- duced air-pressure. The recovery of morphine from the body in cases of fatal poisoning by it is by no means always possible. There are numerous recorded cases of failure of competent chemists to find this alkaloid. In the living body morphine is constantly undergoing decomposition. In the dead body it may suffer de- composition at a very slow rate, though it has been found after standing fourteen months in putrefactive liquids (TAYLOR). It is highly probable that morphine undergoes waste by decom- position during a prolonged analytical separation from tissues. On the other hand, when an analysis is commenced immediately after the introduction of morphine into tissue material, ic can be recovered with less waste than attends some much more stable alkaloids, probably because it interposes a less degree of adhesion 372 OPIUM ALKALOIDS. than they. In experiments instituted by the author l it was found that the loss in the immediate separation of morphine, in its smallest recoverable quantities, from an avoirdupois pound of tissues, was not over one hundred times the quantity needed for recognition by the test of Husemann. In further experiments in the progress of the same investiga- tion, 2 when 0.32 gram of morphine was administered to a cat, an analysis commenced 40 minutes afterward, the alkaloid was re- covered for identification from the stomach, the kidneys, the urine, and from the blood, but not from the liver. In four ex- periments for quantitative recovery, using estimation by Mayer's solution, results were obtained as follows : In each instance 0.32 gram in solution was introduced directly into the stomach by a stomach-tube ; and in each instance the stomach, liver, heart, and kidneys were analyzed together. In No. 4, when the animal was killed 30 minutes after the administration, and the analysis be- gun at once, the volumetric result indicated the recovery of 0.25 gram of alkaloid. When the animal was killed 4 minutes after the introduction into an empty stomach, symptoms having mean- time occurred, and the body then left for two days, the final ti- tration indicated the recovery of 0.208 gram. When the animal was allowed to survive the administration for 14 hours, and the analysis then at once commenced, the four organs gave only 0.05 gram of alkaloid. On the repetition of the last experiment, but with a delay of 2 days between the death and the analysis, 0. 0485 gram was recovered. f. Quantitative. Morphine is usually dried on the water- bath for weight as hydrate, C 17 H 19 NO 3 . H 2 O = 303, 5.94$ water. 1 " Control Analyses and Limits of Recovery," 1885: Proc. Am. Asso. Adv. >Sc*,34, 111; Chem. News, 53, 78, et seq. Prom series, each of four graded trials, by the method of separation substantially as given in the text, and by the qualitative test with sulphuric and nitric acids, the following limits of recovery were fixed for a good color test: From 64 grams of bread, 1 part morphine in 185185 parts. " 64 " tissues, 1 " " 142857 " " 64 " liver, 1 " " 142857 " These " tissues" were membranous, as the coats of the stomach, and con- taining much less fat than the liver. Trial of the volumetric estimation of the recovered morphine, when larger proportions of the alkaloid were taken, indi- cated a much greater and much less consistent loss, as follows: From 128 grams of tissues, 1 part morphine in 19608 parts. " 128 " liver, 1 " " 10870 " The experiments were performed by Mr. S. G. Steiner, at the request of the author. 2 Mr. Steiner, with the author, in 1885, unpublished. MORPHINE. 373 (See a.) But it is recommended to dry at a temperature not above 85 C. for the weight of the hydrate, or at near 120 C. for the weight of the anhydrous alkaloid. The last-named tem- perature is sustained by the anhydrous alkaloid without loss of weight. The washing of finely crystallized morphine with satu- rated morphine solutions has been resorted to by Teschemacher and others, as specified further on. Stillwell (1886) proposes to estimate the meconate of lime left as an impurity in the crys- tallized morphine of an opium assay by dissolving and washing with hot alcohol, on a balanced filter, weighing the dried resi- due, and deducting this weight. Besides this gravimetric determination of the free alkaloid there is no well-established method of estimating morphine. The method next to be named, however, is the volumetric estima- tion with Mayer's solution (see Alkaloids, Volumetric Estima- tion of). The solution is adjusted, if necessary by a preliminary assay, to be of the strength of 1 part alkaloid to 200 parts of the solution, and well acidified with hydrochloric or sulphuric acid (alcohol and acetic acid being always absent in this estimation). Undoubtedly the composition of the precipitate is varied some- what by conditions of concentration and preponderance of mass, as occurs with other alkaloids, but when holding the concentra- tion uniform by a preliminary assay (or more than one) the main conditions are fixed. Degrees of acidulation have little effect (DRAGENDORFF). The end-reaction is found by the completion of th.e precipitate. A filtered drop is tested on glass slide over black paper, with a drop of the reagent ; and several of these test-portions rinsed from time to time, with a drop or two of water, into the solution under titration. According to Mayer (1862), and Dragendorff and Kubly (1874), 1 c.c. of Mayer's "so- lution indicates 0.020 gram morphine hydrate or 0.019 gram anhydrous morphine. The author has obtained results usually a little too low by use of this factor, and recommends standardiz- ing the Mayer's solution with a solution of pure morphine in acidulated water, in conditions of concentration and temperature fixed for the estimation. 1 The composition of the precipitate is given under d, p. 369. An estimation of morphine, in the volumetric and coloro- metric way, by iodic acid, was given by STEIN (1871), by MIL- 1 DRAGENDORFF, 1874: " Werthbestiramung," p. 87. A. B. PRESCOTT, 1878: Pro. Am. Pharm., 26, 812; Jour. Chem. tioc., 38, 192. And 1880: Am. Chem. Jour., 2, 301; Jour. Chem. Soc., 42. 664. The aqueous extract of opium, deprived of morphine, yields to amyl alcohol bodies giving a conside- rable precipitate with Mayer's solution. 374 OPIUM ALKALOIDS. LER (1872), 1 and by SCHNEIDER (1881), and applied to the assay of opium. Aqueous iodic acid is added to a known weight of (opium) solution, and after the lapse of a few minutes the libe- rated iodine is washed out by shaking with carbon disulphide. The sample color thus produced is then compared with a stan- dard color obtained in the same manner from a solution of mor- phine of known strength, and their intensity equalized by add- ing carbon disulphide to the deeper. This method may prove useful in certain exigencies, as where estimations are habitual and there is nothing present besides morphine to reduce iodic acid. The details of the method as improved by Schneider are given where cited. KIEFFER'S a volumetric estimation of morphine consists in a measure of its reduction of potassium ferricyanide. YENTUKINI (1886 3 ) finds this to be the most exact of the volumetric methods. Estimation of Morphine in Opium. Processes of Mprphio- metric Assay. 4 The following is the process of the U. S. Ph., adopted in the Revision of 1880 : u Opium, in any condition to be valued, seven grams (7) ; lime, freshly slaked, three grams (3) ; chloride of ammonium, three grams (3); alcohol [sp. gr. 0.820J, stronger ether [sp. 1 Archiv d. Phar. [2] 148, 150; Phar. Jour. Trans. [3] 2, 465: Jour. Chem. Soc., 25, 180. SCHNEIDER, 1881: Archiv d. Phar. [3J 19,8?; Proc. Am. Pharm., 30, 232. 2 L. KIEFFER, 1857: Ann. Chem. Phar., 103, 271. 3 V. VENTURINI, Oazzetta chim. ital., 16, 239; Jour. Chem. Soc., 50, 1086. 4 In the text following are given the processes of the pharmacopeias of the United States, England, and Germany, with commentary upon their pro- visions, in comparison with each other. Also, the detailed process of Dr. Squibb, the directions of Prof. Fliickiger respecting modifications of the method of the Ph. Germ., and the experimental criticisms of Mr. Conroy, Mr. H. Lloyd, Mr. Still well, and of Messrs. Wrampelmeicr and Meinert, with cita- tions from Portes and Langlois, Prollius, and the Soc. de Phar. of Paris. Of further literature a few references are here added: PERGER, 1884: Jour, prakt. Chem. [2] 29, 97; Jour. Chem. Soc., 46, 1217; Pro. Am. Pharm., 33, 298. PROCTER. 1871: Am. Jour. Phar., 43, 65. ALESSANDRA, 1882: Phar. Jour. Trans. [3] n, 994; Pro. Am. Pharm., 30, 231. A. B. PKESCOTT, 1878: with STECHER, Pro. Am. Pharm., 26, 807; Jour. ("hem. Soc., 38, 191; in 1880. "Report on Revision U. S. Ph.," p. 102; with Moss, 1875: Am. Jour. Phar., -M. /tw.* . -tj.uoviy. t j. < -x\j , _t /ft/ j^-/ Lti^tytoi/j w, -i. .LM t; i< n v u. v/J. -L Ji.ov^jj.n*iu^iv>iixjj.Vj .LV^ i i Chem. News, 35, 47. Report of T. J. WRAMPELMEIER and G. MEINERT, Mich. State Phar. Asso., Oct. 14, 1-886; Am. Druggist, New York, 15, 203. Report of CHARLES M. STILLWELL, 1886: Am. Chem. Jour., 8, 295. A "Bibliography of the Opium Assay" is in preparation by Mr. A. Van Zwaluwenberg, Ann Arbor, and its publication is promised at an early date. MORPHINE. 375 gr. 0.725], distilled water, each a sufficient quantity. Triturate together the opium, lime, and 20 c.c. of distilled water, in a mortar, until a uniform mixture results ; then add 50 c.c. of distilled water, and stir occasionally during half an hour. Filter the mixture through a plaited filter, three to three and one-half inches (75 to 90 millimeters) in diameter, into a wide-mouthed bottle or stoppered flask (having the capacity of about 120 c.c. and marked at exactly 50 c.c.), until the filtrate reaches this mark. To the filtered liquid (representing 5 grams of opium) add 5 c.c. of alcohol and 25 c.c. of stronger ether, and shake the mixture ; then add the chloride of ammonium, shake well and frequently during half ah hour, and set it aside for twelve hours. Counterbalance two small filters, place one within the other in a small funnel, and decant the ethereal layer as com- pletely as practicable upon the filter. Add 10 ^ c.c." of stronger ether to the contents of the bottle and rotate it ; again decant the ethereal layer upon the filter, and afterward wash the latter with 5 c.c. of stronger ether, added slowly and in portions. Now let the filter dry in the air, and pour upon it the liquid in the bottle, in portions, in such a way as to transfer the greater portion of the crystals to the filter. Wash the bottle, and trans- fer the remaining crystals to the filter, with several small por- tions of distilled water, using not much more than 10 c.c. in all, and distributing the portions evenly upon the filter. Al- low the filter to drain, and dry it, first by pressing it between sheets of bibulous paper, and afterward at a temperature be- tween 55 and 60 C. (131 to 140 F.) Weigh the crystals in the inner filter, counterbalancing by the outer filter. The weight of the crystals in grams, multiplied by twenty (20), equals the percentage of morphine in the opium taken." The Br. Ph., in the Revision of 1885, adopted the following process of opium assay: " Take of powdered opium, dried at 100 C., 140 grains [9.072 grams]; lime, freshly slaked, 60 grains [or 3.9 grams] ; chloride of ammonium, 40 grains [2.592 grams] ; rectified spirit (sp. gr. 0.838), ether (sp. gr. 0.735), distilled water, of each a sufficiency. Triturate together the opium, lime, and 400 grain-measures [25.9 c.c.] of distilled water in a mortar until a uniform mixture results ; then add 1000 grain- measures [64.8 c.c.] of distilled water, and stir occasionally dur- ing half an hour. Filter the mixture through a plaited filter, about three inches in diameter, into a wide-mouthed bottle or stoppered flask ^having the capacity of about six fluid-ounces [Imp. meas., or 170 c.c.] and marked at exactly 1040 grain- measures [or 67.4 c.c.]), until the filtrate reaches this mark. To 3/6 OPIUM ALKALOIDS. the filtered liquid (representing 100 grains [6.48 grams] of opium) add 110 grain-measures [7.1 c.c.] of rectified spirit and 500 grain-measures [32.4 c.c.] of ether, and shake the mixture ; then add the chloride of ammonium, shake well and frequently during half an hour, and set it aside for twelve hours. Counter- balance two small filters ; place one within the other in a small funnel, and decant the ethereal layer as completely as practicable upon the inner filter. Add 200 grain-measures [or 13 c.c.] of ether to the contents of the bottle and rotate it ; again decant the ethereal layer upon the filter, and afterwards wash the latter with 100 ^rain-measures of ether added slowly and in portions. Now let tTie filter dry in the air, and pour upon it the liquid in the bottle in portions, in such a way as to transfer the greater portion of the crystals to the filter. When the fluid has passed through the filter, wash the bottle and transfer the remaining crystals to the filter, with several small portions of distilled water, using not much more than 200 grain-measures [or 13 c.c.] in all, and distributing the portions evenly upon the filter. Al- low the filter to drain, and dry it, first by pressing between sheets of bibulous paper, and afterward at a temperature between 55 and 60 C. (131-140 F.), and finally at 96 to 100 C. (194 to 212 F.) Weigh the crystals in the inner filter, counterbalanc- ing by the outer filter." The weight represents the quantity of morphine in 100 grains [6.480 grams] of the opium. The process of the Ph. Germ., adopted in the revision of 1882, is as follows : Opium is to be dried at a temperature not above 60 C. Of opium powder 8 grams are to be agitated with 80 grams of water, and after half a day the mixture nltered. Of the filtrate 42.5 grams are treated with 12 grams of alcohol (sp. gr. 0.834-0.830), 10 grains ether (sp. gr. 0.728-0.724), and 1 gram of ammonia water (sp. gr. 0.960), and the mixture set aside, in a stoppered flask, with frequent shaking, for 24 hours, at a tem- perature of 10-15 C. The contents of the flask are then brought upon a small filter, of 80 millimeters (3^ inches), previously dried and weighed. The crystals recovered from the filtered liquid are washed on the filter with a mixture of 2 grams diluted alcohol (59.8$ to 61.5$ by weight) with 2 grains of water and 2 grams of ether, applying this mixture in two portions. The filter and contents are dried at 100 C. Deducting the weight of the filter, the weight of the alkaloid gives the quantity of morphine in 4 grams of opium. Tlie three pharmacopoeial processes of opium assay agree in taking a stated quantity of the filtrate to represent a stated frac- tion of the opium taken, thereby avoiding the washing of the MORPHINE. 377 undissolved residue of opium, and without concentration obtain- ing a solution of a strength desired for crystallization. The quantity of filtrate used, in proportion to the total quantity of liquid taken with dried opium for the mixture filtered, is pro- vided in each of these respective processes, and by the authors of similar processes, as follows : U S Ph. ...For f of the opium, a vol. of filtrate = f$ vol. of liquids taken. Br.Ph " f " = f oc. Phar. Paris*.... " ^ " " =m " FORTES and LANGLOIS. 2 " f " " " = $ " CONROY 3 ... . " f " " " = ft " " WRAMPEL- MEIER and MEINERT, 1 SS(5 4 5 tt <* _ 50 Ph. Germ.'.'. "' \ " weight " =*2 weight " " PROLLIUS, ~] 1877 5 ... [ t t 4 (( ( t _ . 43.5 < " FLUCKIGER, f so.o 1885 6 ...J The U. S. and Br. pharmacopoeias, and, earlier, the Pharma- ceutical Society of Paris, take out of the filtrate an aliquot por- tion of the total volume of liquid introduced into the solution subjected to filtration, making no allowance for the volume of solvents being increased by taking solids into solution. Still earlier Portes and Langlois seem to have made such an allow- ance by the increase of 50 c.c. to 53 c.c. Mr. Conroy (1884) assumes that the " 50 c.c. contain the extractive of 5 grams of opium, equal to about 3 grams in the moist state [italics added] in which it exists in opium. This, from experiments that I have tried, increases the bulk to 52 c.c." Recently Messrs. Wrampelmeier and Meinert have given (Loc. cit.) report of direct experimentation on the question "whether the total liquid that is, the 70 c.c. of water plus the J Societe de Phaniiacie, Paris adoption of a modification of the process of Portes and Langlois, 1882: Phar. Zeitung, No. 6, from Jour, de Phann. d y Al- sace-Lorraine ; Am. Jour. Phar., 54, 598. 2 PORTES and LANGLOIS, 1881: Jour, de Pharm. et de Chim., 1881, 399; New Rem., n,64: Chem. News, 45, 67. 3 CONROY, 1884: Phar. Jour. Trans. [3] 15, 473. 4 Proceedings Mi<*Ji. State Phar. Asso., 4, 127; Am. Druggist, New York, 15, 203. 5 PROLLius, 1877: Schweiz. Wochenschr. f. Phar., 1877, 381; Proc. Am. Pharm., 26, 276. 6 FLUCKIGER, 1885: Archiv der Phar. [3] 26 ; Am. Druggist, 14, 149. The Ph. Germ, process was contributed by Fliickiger, who presents, later, a slight modification, noticed in the text further on. 373 OPIUM ALKALOIDS. extractive matter dissolved thereby is really more in volume than 70 c.c. or not." These experiments 1 obtained an average total volume of liquid of but 70.29 c.c., and, so far as they ex- tend, go to support the rate adopted by the U. S. Ph. The method of the Ph. Germ, and of Professor Fliickiger, in which for A of the opium a weight of filtrate is taken equal to |ff the 1 Following is the original report of the experiments of Messrs. Wrampel- meier and Meinert (loc. cit.): 7 grams of powdered opium were taken, dried at 100 C., and transferred to a flask. A flask was used instead of a mortar, in order to avoid loss by evaporation. Three grams of freshly slaked lime and 70 c.c . of water were added, the whole thoroughly mixed and allowed to stand for half an hour. The mixture was then placed upon a filter and (instead of 50 c.c.} the liquid was drained off as much as possible by means of an aspirator. The filtrate was weighed, and its specific gravity taken. In order to determine how much liquid there was left in the opium on the filter, the filter was weighed with the funnel, dried at 100 C. to constant weight, and again weighed. By multiplying the loss in weight by the specific gravity of the filtrate, the weight of the liquid left in the opium was found. In the same manner the weight of the liquid left in the macerating flask which could not be brought upon the filter was determined. The weight of total liquid was then found by adding to the weight of the filtrate the weight of liquid left in the opium on the filter, and that of the liquid left in the flask, and from this the total volume i.e., the 70 c.c. plus the extractive matter dissolved thereby was calculated by di- viding by the specific gravity. On working two samples of powdered opium in this way, the volume was found to be in the one case 70.83 c.c., and in the other it was 70.85 c.c. ; where- as, according to Conroy, the volume should be 72.8 c.c. Since the U. S. Ph. directs to take opium in any form, it seemed possible that, if lump opium which contains some moisture be used, the volume of liquid might be increased. A sample of lump opium was taken which contained 11 per cent, of moisture. Seven grams were weighed off, cut into small pieces, and transferred to a flask. Then the lime and 70 c.c. of water were added, the whole thoroughly mixed s obtained. by means of a stirring rod until a uniform mixture was obtained. The mixture was then allowed to stand for half an hour and finally placed upon a filter. The filtrate was weighed and its specific gravity taken, and the weight of the liquids left in the opium on the filter, and that of the liquid left in the flask, were calculated in the above-described manner. Experiments made with two samples gave the following results: Specific gravity of Per cent, of morphine' Total liquid. Experiment I 1.01270 1.01265 UM 8.3 per cent. 9.04 " 70.39 c.c. 70. 19 c.c. Experiment II Aver 70.29 c.c. This gave an average increase of 0.29 c.c. Then a very moist lump opium containing 20.7 per cent, moisture was used, and the volume of liquid was found to be, in this case, 70.61 c.c. These experiments, therefore, would seem to prove that the volume of filtrate directed to be taken by the Pharmacopoeia (50 c.c.) is nearly correct. MORPHINE. 379 weight of the liquids used with the dry opium, depends upon dry opium containing | of its weight (62 5$) of soluble mat- ter. The proportion of soluble matter in opium is, at all events, quite variable. HERBERT LLOYD ! found that when morphine itself is sub- jected to the U. S. Ph. process of assay, it suffers a loss equal to from 0.060 to 0.089 gram on the yield of the 50 c.c., greater or less according to the taking of greater or smaller quantities of morphine. Of course it should be understood that an alka- loid cannot be obtained by a single crystallization, as in all established methods of the morphiometric assay of opium, with- out some loss; nevertheless the result becomes practically a true one when the quantity of the loss is made to equal an average balance of the quantity of impurity remaining in the crystals weighed. It appears from all evidences to be not improbable that, by the U. S. Ph. or Br. Ph. process, the loss of weight of real morphine, whatever its sources, exceeds the weight of impurity with the morphine. The quantity of ammonium chloride introduced into the filtrate is to the quantity of dried opium represented in the filtrate, by the directions of the U. S. Ph. as well as by the process of Portes and Langlois, in the proportion of 3 : 5 ; by the Br. Ph. it is 2 : 5. Mr. Conroy (where cited) reports ex- periments showing that excess of ammonium chloride causes proportional diminution of yield. The truth of this conclusion has been confirmed by Messrs. Wrampelrneier and Meinert (1886, loo. cit.) From these observations and those of Lloyd (loc. cit.) it appears that morphine and lime exert a mutual sol- vent action on each other, and that other constituents of opium help to dissolve lime. The more lime the more free ammonia. And both free ammonia and remaining ammonium chloride help to dissolve the morphine. 8 It appears, therefore, that the pro- '1885: Am. Druggist, New York, 14, 221. 2 " In order to find out whether the morphine is held in solution by the excess of ammonia liberated or by the excess of ammonium chloride, the fol- lowing experiments were made. By calculation it was found that, when 202 gram of calcium oxide is in solution, 0.399 gram of ammonium chloride is decomposed. Subtracting this from 3 grams, we find that in this case there is an excess of 2.61 grams of ammonium chloride present in the assay liquor. This amount of ammonium chloride was then dissolved in 50 c.c. of pure water and 0.500 gram of morphine added, and the solution allowed to stand for 12 hours, after which time 0.500 gram of morphine had lost 0.135 gram. The amount of ammonia which would be set free in such assay was also calculated, and a solution of 50 c.c. of pure water containing that amount of ammonia was found to dissolve, after 12 hours' standing, 110 gram of mor- phine. Thus it was shown that both ammonium chloride and free ammonia in 38o OPIUM ALKALOIDS. portion of ammonium chloride directed by the Br. Ph. is advis- able. The quantity of free ammonia liberated from the ammo- nium chloride in the filtrate is limited by the slight but vary- ing solubility of the lime. The excess of lime in the primary maceration serves to improve the consistence of the inucila- finous matters of the opium, favoring solution and filtration, his use of lime in excess, which first holds the alkaloid mor- phine in an alkaline solution, and afterward, in the filtrate, be- comes exchanged for free ammonia, (2NH 4 C1 -f Ca(OH) 2 = 2NH 3 + CaCl 2 + 2IT 2 O), is credited to the plan of MOHE. Whether liberated by lime from ammonium chloride, or added in water of ammonia (as by the Ph. Germ.), at all events free ammonia is employed in separating morphine from its com- pounds, to crystallize on standing, in all methods of morphio- metric assay so far well established in use. The crystallization of the alkaloid requires time. In the Hager-Jacobsen processes crystallization was promoted, and the crystals purified, by the addition of small quantities of ether and benzene, not too much to be taken into solution in the crystallizing liquid. The use of an excess of ether, much beyond ether-saturation, so as to cause an ether layer to rise above the crystallizing liquid, along with the frequent shaking up of the ether with the aqueous liquid in the closed flask during crystallization, marks an important prac- tical advance in opium assay. This use of ether, introduced about 1881, has been adopted in each of the three pharmaco- poeial processes above given, also in the processes on individual authority, as hereafter presented. By this use of immiscible ether in forcible contact by agitation with the aqueous solution, crystallization is greatly quickened, and purer crystals are ob- tained. The effect of stirring was emphasized in 1877 by Tesche- macher, who says : " The rapid and continuous stirring is most important, as the precipitation of the whole morphine in fine powder is thereby effected, instead of the granular or manimil- lated condition so frequently met with." This effect on crystal- line precipitates, in numerous analytical operations, is well under- stood at present. The addition of alcohol, in the crystallizing liquid, is well understood to cause whiter and finer crystals to be obtained, but, unless counteracted with ether or by greater solution exert a distinct solvent action upon the alkaloid. It is therefore probable that by using about 1.000 gram of ammonium chloride instead of 3.000 grams, the amount of morphine held in solution will be greatly re- duced." WKAMPELMEIER and MEINERT, 1886: Am. Druqqist, New York, 15, 203. MORPHINE. concentration, alcohol in proportion to its quantity tends to di- minish the yield of crystals. By the processes of the Ph. Germ, and Professor Fliickiger, alcohol, ether, and aqueous liquid hold the proportions by weight 12 : 10 : 43.5 in the crystallizing liquid. By the Br. Ph. process these proportions are by volume nearly as 4 : 2 ) : 41 ; and by the U. S. Ph. process, as 5 : 25 : 50. Thetis, for 100 parts ly weight of aqueous solution, the crys- tallizing liquid contains, in parts by weight, nearly as follows : U. S. Ph. Br. Ph. Ph. Germ. Of Alcohol Of Ether 8 (sp. gr. 0.820) 35 (sp. gr. 0.725) 9 (sp. gr. 0.838) 35 (sp. gr. 0.735) 28 (sp. gr. 0.832) 23 (sp. gr. 0.720) The directions given by Prof. Fliickiger. in 1885, 1 slightly modified from those of the Ph. Germ., are as follows : u Place 8 grams of powdered opium upon a filter of 80 millimeters (3i inches) diameter, and wash it gradually with 18 grains (or 25 c.c.) of ether, the funnel being kept well covered ; force out the last drops of filtrate by tapping the funnel, dry the opium on a water-bath, transfer it to a small flask containing 80 grams of water at 25 C., and shake well repeatedly. After 12 hours pour the mixture on the previously used filter, and collect 42.5 grams of the filtrate in a small flask, to which add 12 grams of alcohol [sp. gr. 0.832], 10 grams of ether [sp. gr. 0.726], and 1 gram of ammonia-water [sp. gr. 0.960], stopper well, set aside at a temperature of 12 to 15 C., and shake repeatedly. After 24 hours moisten a new tared filter of 80 millimeters [3 inches] diameter with ether, pour upon it the ethereal layer in the flask, add 10 more grams [14 c.c.] of ether to the latter, and shake well. Again pour the ethereal layer upon the filter. When this has passed, pour the whole contents of the flask upon the filter, and wash the crystals of morphine twice with a mixture of 2 grams of diluted alcohol (sp. gr. 0.892), 2 grams of water, and 2 grams of ether. Dry at a gentle heat, finally at 100C., and weigh, adding the morphine which may still adhere to the inside of the flask. Prof. Fliickiger prefers to weigh the morphine in the flask instead of on the filter. The concentration of the (aqueous) solution set for the crys- tallisation of the morphine in an opium assay is very nearly 1 to 10, the same in each of the four processes which have been given -those of the Ph. Germ., Br. Ph., U. S. Ph , and Professor 1 See foot-note on p. 377. 382 OPIUM ALKALOIDS. Fliickiger. In these processes 10 c.c. of water are taken for each 1 gram of opium, with little addition to alter this proportion, which is nearly retained in the crystallizing liquid. 1 In the pro- cess next to be given, that of Dr. Squibb, the plan of using an aliquot part of the digestive solution is rejected. The undis- solved residue of opium is to be exhausted and washed clean, the total filtrates reaching near 20 c.c. for each 1 gram of opium. The entire solution is to be reduced in volume by evaporation, the washings separately, until brought to about 2 c.c., increased, by transfer rinsing and by ammonia-water, to about 3 c.c. of crystallizing liquid for 1 gram of the opium taken. The ether, of course, is not to be counted as solvent, since it serves as an anti-solvent in all the processes. This greater concentration of volume undoubtedly diminishes the loss a due to morphine left in the mother-solution, and increases the gain due to impurities held in the morphine crystals. 3 The relation between this loss and this gain,, in opium assay, was mentioned on p. 379. The process of Dr. E. R. Squibb* published in 1882, is as follows : " Take of opium in its commercial condition 5 10 grains 1 Wrampelmeier and Meinert (loc. cit.) object to the U. S. Ph. direction to triturate and digest in an open mortar, and to measure in a wide-mouthed bot- tle or flask, as liable to cause some concentration by evaporating. Such con- centration of volume interferes with the principle of taking an aliquot part, and tends toward too high results. 2 "About 10 per cent, of the morphine in the opium is retained in the mother-liquor after crystallizing the morphine according to the U. S Ph." " In order to determine how much of the alkaloid is dissolved in the mother- liquor after crystallizing the morphine, a solution was made to correspond as nearly as possible to the assay liquor, and then a certain amount of morphine was used. The amount of lime (CaO) found to be present in the mother-liquor of the lump opium was 0.202 gram. This amount of lime was taken, slaked with a little water, transferred to the flask, and 50 c.c. of distilled water were added. On adding then 0.500 gram of pure morphine it was found that some of the lime was left undissolved. Therefore, in another trial, a little less calcium ox- ide was used, the 50 c.c. of water and 0.500 gram of morphine added. Then, as in the U. S. Ph. process, 5 c.c. of alcohol, and 25 c.c. of ether, and 3 grams of ammonium chloride were added, and the mixture allowed to stand for 12 hours. The amount of morphine obtained was 0.442 gram, showing that of the 0.500 gram taken 0.058 gram was retained in solution in the mother-liquor." WRAMPELMEIER and MEINERT, Am. Druggist, New York, 15, 203. 3 " The precipitate of morphine obtained by Dr. Squibb's process contains insoluble matter, resinous and other organic matters soluble in alcohol, and meconate of lime, the latter constituting about 25 per cent, of the impurities present. The average amount of the impurities present in the crystals obtained by his process is 8 per cent, of the weight of the crystals." CHARLES M. STILL- WELL, Am. Chem. Jour., 8, 306. 4 1882: Ephemeris, i, 14; Jour. Chem. Soc., 42, 666. Further, see WAIN- WRIGHT, 1885: Jour. Am. Chem. Soc., 7, 45. 8 " If of lump opium, every tenth lump of a case should be sampled by cut- ting out a cone-shaped piece from the middle of the lump. Then from the side MORPHINE. 383 (154.32 grains). Put the weighed portion in a flask, or common wide-mouthed vial of 120 c.c. (4 f. oz.) capacity, tared and fitted with a good cork. Add 100 c.c. (3.3 f. oz.) of water, and shake well. Allow it to macerate over-night, or for about 12 hours, with occasional shaking, and then shake well and transfer the magma to a filter, of about 10 centimeters (4 inches) diameter, which has been placed in a funnel and well wetted. 1 Filter off the solution into a tared or marked vessel, then percolate the residue on the filter with water dropped on the edges of the fil- ter and on the residue, until the filtrate measures about 120 c.c. (4 f. oz.), and set this strong" solution aside. Then return the residue to the bottle by means of a very small spatula, without breaking or disturbing the filter in the funnel, add 30 c.c. (1 f. oz.) water and shake well, and return the magma to the. filter. When drained rinse the bottle twice, each time with 10 c.c. (^ f. oz.) water, and' pour the rinsings upon the residue. When this has passed through, wash the filter and residue with 20 c.c. (| f . oz.) of water, applied drop by drop around the edges of the filter and upon the contents. When the filter has drained there should be about 70 c.c, (2f f. oz.) of the weaker solution. 8 The filter and residue are now to be dried until they cease to lose weight at 100 C. If any residue remains in the bottle, the bot- tle is also to be dried in an inverted position and weighed. [The weights show the quantity of insoluble matter in the opium.] Evaporate the weaker solution in a tared capsule of about 200 c.c. (6f f. oz.) capacity, without a stirrer, on a water-bath until of the cone a small strip is taken from point to base, not exceeding say half a gram from cones which would average 10 to 15 grams. The little strips are then worked into a homogeneous mass by the fingers, and the mass is then wrapped in tin-foil to prevent drying, until it can be weighed off for assay. When opened to be weighed off it is best to weigh off at once three portions of 10 grams each. In one portion the moisture is determined by drying it on a tared capsule until it ceases to lose weight at 100 0. Another portion is used for the immediate assay, and the third is reserved for a check assay if desira- ble." . . . Opium "should not be dried, but should be weighed for the assay in the condition in which it is found in the market, and in which it is to be dis- pensed." 1 "If the shaking be frequent and active," "the time of maceration can easily be shortened even to three hours." The author of the process states that exceptional opiums give a magma which will not filter, and advises to treat such with ether before the assay, washing in a bottle with 30 c.c. ether, shak- ing well, and washing further with 10 c.c. ether and drying on a filter. 2 "This (120 + 70 = ) 190 c.c. (6 f. oz.) of total solution will practically ex- haust almost any sample of opium. But occasionally a particularly rich opium, or one in coarse powder, or an originally moist opium which has by slow drying become hard and flinty, will require further exhaustion. In all such cases, or cases of doubt, the residue should be again removed from the filter and shaken with 30 c.c. (1 f. oz.) of water, and returned, and be again washed as before." 384 OPIUM ALKALOIDS. reduced to about 20 grams (309 grains). Now add the 120 c.c. of stronger solution, and evaporate the whole again to about 20 grams (309 grains). "When cool add 5 c.c. (0.17 f. oz.)of alcohol (sp. gr. 0.820), and stir until a uniform solution is obtained and there is no ex- tract adhering undissolved on the capsule. 1 Pour the concen- trated solution from the capsule into a tared flask of about 100 c.c. (3| f . oz.) capacity, and rinse the capsule into the flask with about 5 c.c. of water used in successive portions. Then 2 add 30 c.c. (1 f. oz.) of ether, and shake well. Add now 4 c.c. (0.133 f . oz.) of water of ammonia of ten per cent. (sp. gr. 0.960), and shake the flask vigorously until the crystals begin to separate. Then set the flask aside in a cool place for 12 hours, that the crystalli- zation may be completed. 3 Pour off the ethereal stratum from the flask, as nearly as possible, on to a tared filter of about 10 centimeters (4 inches) diameter, well wetted with ether. Add 20 c.c. (f f. oz.) of ether to the contents of the flask, rinse round without shaking, and again pour off the ethereal stratum as closely as possible on to the filter, keeping the funnel covered. Whe^n the ethereal solution is nearly all through, wash down the edges and sides of the filter with 5 c.c. (0. 17 f . oz.) of ether, and allow the filter to drain with the cover off. Then pour on the remain- ing contents of the flask and cover the funnel. When the liquid has nearly all passed through, rinse the flask twice with 5 c.c. (0.17 f. oz.) of water each time, pouring the rinsings with all the crystals that can be loosened on to the filter, and dry the flask in an inverted or horizontal position, and, when thoroughly dry, weigh it. Wash the crystals with 10 c.c. (-J- f. oz.) of water applied drop by drop to the edges of the filter. When drained, remove the filter and contents from the funnel, close the edges of the filter together, and compress it gently between many folds of bibulous paper. Then dry it at 100 C. and weigh it. Remove the crystals of morphine from the filter, brush it off, and re- weigh it to get the tare to be subtracted. The remainder, added to the weight of the crystals in the flask, will give the total yield of morphine in clean, distinct, small light-brown crystals." 1 " If this solution should contain an appreciable precipitate, as from rare specimens of opium it will, it must be filtered, and the filter be carefully wash- ed through. Then the filtrate must be evaporated to 25 or 30 grams.*' 2 "If it has been filtered and evaporated, add 10 c.c. (\ f. oz.) of alcohol and shake well." 3 " If the shaking be frequent and vigorous, 2 or 3 hours' time will be suf- ficient to complete the crystallization; or if it be continuous, half an hour will be sufficient, but as a rule it is better to allow the flask to stand over-night." MORPHINE. 335 As to the tests for purity of the recovered morphine, see g, p. 386. To effect a complete washing of the crystallized morphine without loss, TESCHEMACHER, in 187T, 1 resorted to the use of a saturated aqueous solution of morphine and a saturated alcoholic solution of morphine as washing liquids. The " inorphiated water " was simply a saturated solution, and contained 0.01 per cent, of the alkaloid. The " inorphiated spirit " was prepared by mixing 1 part of ammonia-water, sp. gr. 0.880, with 20 parts of (methylated) alcohol, and digesting a large excess of morphine in this mixture for several days. It contained 0. 33 per cent, of morphine. STILLWELL, 1886," adopts this way of washing the crystallized morphine obtained by Squibb's process. He col- lects the crystals on balanced filter-papers of 4J inches diameter. The ethereal stratum of the crystallizing liquid is poured through the filter, washing out several times with 10 c.c. of ether, rinsing the flask around without shaking it, letting settle for a few minutes, and decanting upon the filter. If the aqueous solution pass on to the filter it is of no importance. The washing with ether is followed, first, by a thorough washing with the " inorphiated spirit," then by a thorough washing with the " morphiated water," and, after draining, by two more washings of 10 c.c. each of " morphiated spirit." After draining a few minutes, while the funnel is covered with a watch-glass, two additional washings, each with 10 c.c. of ether, are made. " This will re- move any narcotine which may have been left from the evapora- tion of the ethereal solution at the beginning of the operation. The paper and contents are thus left in a condition to be rapidly dried. Let the filter and its contents stand exposed for a few minutes, and then dry at 100 C. and weigh. Twenty minutes' or half an hour's drying is usually sufficient." The purification of the crystals from meconate of lime and any other matters insoluble in hot alcohol, as used by Stillwell, was stated on page 373. The Estimation of Morphine in Tincture of Opium. The following are the directions of Mr. H. B. PARSONS in application of the U. S. Ph. process of morphine estimation to laudanum. 8 Of the laudanum 75 c.c. are evaporated to dryness on the water- 1 E. F. TESCHEMACHER, Chem. News, 35, 47; Jour. Chem. Soc., 32, 231- 232. 2 CHARLES M. STILLWELL, Am. Chem. Jour., 8, 295. 3 " The Composition of the Laudanum generally dispensed in the State of New York," with report of forty-eight samples, 1883: New York State Phar. Asso., New Rem., 12, 194. 3 86 OPIUM ALKALOIDS. bath. When cool, 75 c.c. of water are added, together with 3 grams of water-slaked lime. Thorough admixture is attained by trituration at intervals during half an hour. The liquid is fil- tered (from calcium meconate and other insoluble matters), and 50 c.c. of the filtrate (representing 50 c c. of laudanum) is placed in an assay-flask for treatment. Now add alcohol (sp. gr. 0.820), 5 c.c. ; ether (sp. gr. 0.725 or lower), 25 c.c. ; ammonium chlo- ride, 3 grams. Shake the mixture in the corked flask several times during the first half-hour, and occasionally afterward. After 12 or more hours' standing the crystals are gathered on a small balanced filter, slightly washed with cold water, dried at 60 C. (140 F.), and weighed. The grams of this weight, multiplied by 2 (for 100 c.c. of the laudanum) and by the specific gravity of the laudanum, equal the per cent, of morphine in the sample assayed. Tincture of opium of the U. S. Ph., 1880, is required to be made from one-tenth its weight of dry opium (powdered opium, U. S. Ph.) g. Impurities. " On adding 20 parts of colorless solution of soda or potassa to 1 part of morphine, a clear, colorless solu- tion should result, without residue (absence of other alkaloids) " (U. S. Ph.) "The watery solution of morphine salt is readily made turbid by addition of potassium carbonate. Ammonia gives a precipitate not sensibly soluble in excess of ammonia or in ether, but soluble both in lime solution and in soda solution " (Ph. Germ.) " Take a small portion of the crystals [free morphine from the opium assay], rub them into very fine powder, and weigh off 0.1 gram. Put this in a large test-tube fitted with a good cork, and add 10 c.c. of officinal lime-water. Shake occasionally, when the whole of the powder should dissolve (absence of nar- cotine) " (FLUCKIOER, SQUIBB). " The lime-water test for the narcotine in the results of the assay is quite sufficient, since no- thing, except coloring matter, is so likely or so liable to be present as narcotine. The only difficulty is to know when the lime water has surely dissolved all it will dissolve. This is facilitated by having a very fine powder, and then good judgment is re- quired to know the value or significance of undissolved residues when they are small" (E K. SQUIBB, 1882). " Morphine yields a colorless solution with cold concentrated sulphuric acid, which should not acquire more than a reddish tint by standing some time" (U. S. Ph.) This test, applied with care, gives good comparative indications of the proportions of narcotine. NARCOTINE. 387 If 0.5 gram of morphine sulphate be dissolved in 15 c.c. of water, with the addition of 5 drops of sulphuric acid, and the solution washed with four or five portions each of 25 c.c. of stronger ether, and the united ethereal solutions be evaporated, the narcotine, if any, will be found in the residue. The amount of this residue, and the intensity of its color under action of concentrated sulphuric acid, furnish comparative evidences of the quantity, or comparative quantities, of narcotine as an im- purity in the morphine salt. NARCOTINE. C 22 H 23 N0 7 = 413. (For structure see p. 361.) Occurs in opium, in very variable proportions, from 1.3$ to 10.9$. Some samples of French opium do not contain any re- coverable by ordinary methods. T. and H. SMITH found an al- kaloid, aeonelline, in the roots of Aconitwni Napellus, which they thought was identical with narcotine. Narcotine is characterized by its deportment with pure sul- phuric acid, and with sulphuric and nitric acids (d) ; distin- guished and separated from morphine by its solubility in ether (c., 3 (1885), 158. Results of plant analyses by Mr. Parsons himself are extant as follows: Analysis of "damiana" (Turnera aphrodisiaca), 1880: New Remedies, 9, 261; Phar. Jour. Trans. [3] u, 271. Of " Eupatoriura perfoliatum," 1879: Am. Jour. Phar., 51, 342; Archiv der Phar. [3] 15, 557. Of "Berberis aquifo- lium (var. repens)," 1880: New Remedies, n, 83; Phar. Jour. Trans. [3j 13. 46; Ber. d. chem. Ges , 15, 2745. Of "Ustilago maidis (corn smut)," 1880: New Remedies, n, 80; Phar. Jour. Trans. [3] 12, 810. Plant analyses in the Reports of the Department of Agriculture at Washington, for 1880, 1881, 1882, as accredited to Mr. Parsons by the chemist, Dr. Collier. See also an excellent article by Mr. Parsons on "Some Constituents of Plants," 1879: New Reme- dies, 8, 168. PAKSONS'S METHOD FOR THE CHEMICAL ANALYSIS OF PLANTS/ Prefatory. It must be premised that no one method is applicable in all cases, and that the operator will so modify and adapt the proposed processes as to best attain the truths he seeks. If the present scheme shall serve merely as an example, to be improved upon as discoveries multiply, it will at least have served to stimulate to the more thorough study of a much-neglected yet very important branch of analysis. The student, when first entering upon the study of plant analysis, is perplexed and disheartened, owing to the lack ,of any elementary treatise in which he may find directions for the quantitative estimation of the various plant constituents. The works of Rochleder and Wittstein, while giving most valuable assistance in the investigation of special constituents and their separation from large quantities of the crude herb, still fail to give clear and practicable directions for the quantitative estimation of each constituent. Von Mueller's latest enlarged edition of Wittstein's " Plant Analysis " gives a scheme, most excellent in many respects, yet cumbered with tiresome methods of extraction and manipulation, which serve to unnecessarily lengthen the time required for making the analyses, without increasing the accuracy of results obtained. Too many American analyses of plants have been summarized thus: "The plant contains gum, resin, tannin, a volatile oil, and a peculiar bitter principle, to which may be ascribed its medicinal activity." The foreign journals bring occasionally most excellent examples of accurate examinations of vegetable sub- stances; as instances may be cited the examination of ginger, by J. C. THRF.SH, 2 and of ergot, 6 aloes, 4 and other articles by Prof. DRAGENDORFF. To these sources the student must look for his best models (p. 407 and above). 1 The publications of this method are cited above, p. 407. Mr. Parsons disclaimed any aim to originality, in the resources used in the scheme (presented at request of the author of this work), but submitted the plan as an outgrowth of his own experience, in a varied practice of chemical analysis of plants and vegetable tissues. 2 Phar. Jour. Trans. [3] 10, 81, Aug., 1879; Am. Jour. Phar., 1879, 51, '*Phar. Jour. Trans. [3] 6, 1001, June 17, 1876; Am. Jour. Phar , 1876, p. 413; 1878, p. 335. 4 " Werthbestimmung," 1874, p. 110. PARSONS' 'S METHOD. 409 In following the plan now presented, the use of the apparatus for con- tinuous percolation is strongly urged for the extractions with benzene, alcohol, and other volatile solvents. A very simple and inexpensive " extraction appa- ratus " has been described by various American and foreign chemists. 1 "In any convenient water-tight vessel is a worm of block-tin pipe, having an internal diameter of 9 mm. and a length of about 2.5 meters. The lower (external) part of this worm is fitted by an ether-soaked velvet cork to a glass percolator having a diameter of 4 cm., a length of 20 cm. to the constriction, and 5 cm. below. Within this percolator is a smaller tube, flanged at the top and bottom, and suspended by fine platinum or copper wires. This tube has a diameter of 2.5 to 2.8 cm. and a length of 14 cm. ; the bottom is covered by filter-paper and fine washed linen, 2 tied on by linen thread. The weighed sam- ple of the finely powdered herb is placed within this tube for extraction. A light glass flask, weighing about 30 grams, is fitted by an ether-soaked cork to the outer percolator." Having introduced the solvent into this glass flask, the connections are made secure, and heat is applied by a water-bath to the flask. If the liquid is too slowly volatilized the addition of a little common salt to the water in the bath serves to remove the trouble. Next in importance is the use of a good tared filter. The form originally presented by F. A. GOOCH 3 leaves little to be desired. It may be made by per- forating with fine holes the bottom of an ordinary platinum crucible, and fit- ting it accurately to a perforation made in a large rubber cork ; this cork con- nects it with a receiving vessel, which in turn is connected with a Bunsen's pump. Fine asbestos suspended in water is poured into the crucible, the air exhausted from the receiving vessel, and thus a firm, thin layer of asbestos is deposited on the bottom of the crucible. After ignition and weighing, the cru- cible is ready for the reception of any precipitate which it is desired to separate and weigh. The use of these two pieces of apparatus will eliminate two grave sources of error, viz., incomplete extraction of soluble matters, and inaccuracies intro- duced by the use of tared paper filters. The other necessary apparatus is simple, and includes one or more plati- num crucibles and evaporating dishes, accurate burettes and graduated cylin- *B. TOLLENS: Zeitsch. anal. Chem., 17, 320 (1878): New Remedies, 7, 335, Nov., 1878. W. 0. ATTWATER: Proc. Am. (hem. Sw., 2, 85 (illustrat- ed). S. W. JOHNSON: Am. Jour. Sd., 13, 196. H. B. PARSONS: New Remedies, 8, 293 (illustrated), Oct., 1879. F. SOXHLET, 1879: Ding, polyt. Jour., 232, 461; Zeitsch. anal. Chem.. 19, 365. MEDICUS, 1880: Zeitsch. anal. Chem., 19, 168; New Remedies, 9, 167 (illustrated). 2 In place of the linen and filter-paper may be substituted fine brass or plati- num wire gauze. Asbestos suspended in water may then be poured in to form a fine felt. The tube can then be dried and weighed, and the amounts ex- tracted may be found by the loss of weight of the tube and substance. A little experimentation will show the operator how to prepare and use the tube. It is but an adaptation of the Gooch's Filter here recommended. 3 P/-oc. Am. Acnd. Sci., 13,342 (1878); New Remedies, 7, 200 (Oct., 1878); Am. Chem. Jour., i, 317 (illustrated). 4 io PLANT ANALYSIS. ders, a good balance sensitive to at most 0.0005 gram, and the ordinary glass and porcelain-ware found in all laboratories. It is assumed that whoever attempts the analysis of a plant is informed as to the normal constituents to be sought, and that he has had considerable expe- rience in inorganic analysis and in the identification of the principal classes of proximate constituents which he now undertakes to estimate quantitatively. ,Accordingly, tests for identification will not be here presented ; they should, however, never be omitted. The necessity of recording in detail all physical and chemical peculiarities with every weight that is taken is self-evident. I. Preparation of Sample. The air-dry specimen should be carefully examined, and all extraneous substances removed. The entire sample should then be ground, or beaten in an iron mortar, until it will all pass through a sieve having from 40 to 60 meshes to the linear inch. After thoroughly mixing this sample, take of it about 100 grams, which should be further pulverized until it will all pass through a sieve having from 80 to 100 meshes to the linear inch. From this smaller portion remove all iron, derived from mill or mortar, by use of a magnet. Then place in a clean, dry bottle, which should be labelled and securely corked. This small sample is for the analysis ; the larger portion should be reserved for the sepa- ration of those proximate principles which seem, from the analy- sis, to be worthy of more extended investigation. II. Estimation of Moisture. Dry rapidly, at 100 to 1 20 C., two or more grams of the sample ; the loss of weight equals moisture and occasionally a little volatile oil. In some cases it is best to dry at a lower tem- perature, and at other times the drying should be conducted in a stream of hydrogen or carbonic anhydride. 1 III. Estimation of Ash. In a weighed crucible gently ignite two or more grams of the sample until nearly or quite free from carbonaceous matter ; the heat should not be permitted to rise above faint redness, or loss of alkaline chlorides may occur. Weigh this residue as crude ash, and in it determine : a. Amount Soluble in Water. This portion may contain chlorides, sulphates, phosphates, and carbonates of potassium and sodium ; also slight amounts of chlorides and sulphates of cal- cium and magnesium. see 1 On treatment of fresh plants for drying, and on methods of powdering, DragendorfFs " Plant Analysis," London edition, p. 6. PARSONS' S METHOD. 411 b. Insoluble in water; Soluble in Dilute Hydrochloric Acid. The residue from a should be treated with a slight ex- cess of hydrochloric acid, and evaporated in a porcelain dish over a water bath until all free acid has been expelled ; it should then be again moistened with hydrochloric acid, water added, and be filtered from any remaining insoluble substances. This treatment removes carbonates (with decomposition) and phos- phates of calcium and magnesium, sulphate of calcium, and ox- ides of iron and manganese. c. Insoluble in Water; Insoluble in Dilute Hydrochloric Acid ; Soluble in concentrated Sodium Hydrate. Boil the resi- due from b with a solution containing about 20 per cent, of sodium hydrate. This treatment removes combined silica of the ash. The residue still insoluble is sand and clay which adhered to the specimen ; this residue should be separated, washed tho- roughly, and weighed. Always determine the amounts removed by the above treat- ment by weighing the dried, undissolved residues. The ash, as thus estimated, usually includes a little unconsumed carbon, to- gether with more or less carbonic anhydride, most or all of which was not originally present in the plant, but was produced by the combustion of the organic matter. For most purposes it is unnecessary to estimate and exclude from the ash this carbonic anhydride ; where great accuracy is desired, a complete quantita- tive analysis should be made, the amount of each base and acid being determined, and in the statement of results only those should be included which existed originally in the plant. For this purpose it is necessary to burn from 20 to 100 grams of the sample ; for further directions consult text books on agricultural and inorganic analysis. \, IY. Estimation of Total Nitrogen. In half a gram or more of the sample determine total nitro- gen by combustion [p. 230 or 229]. If later in the analysis no other nitrogenous substances are discovered, calculate the total amount of nitrogen to albuminoids by multiplying by 6. 25 [or 6.33]. When other nitrogenous compounds are present, their content of nitrogen should be determined directly or by diffe- rence ; after proper deductions have been made, the remaining nitrogen should be calculated to albuminoids. ^4- Y. Estimation of Benzene Extract. In a suitable extraction apparatus completely exhaust 5 grams of the sample with pure coal-tar benzene (sp. gr. 85-88, boil- 412 PLANT ANAL YSIS. ing at 80 to 85 C., leaving no residue when evaporated). The extraction requires from four to six hours' continued action of the solvent. Carefully evaporate this liquid to dryness in a weighed dish, and record its weight as total benzene extract. This extract may contain volatile oils and other aromatic com- pounds, resins, camphors, volatile or non-volatile organic acids, wax, solid fats, fixed oils, chlorophyll, other colors, volatile or fixed alkaloids, glucosides, almost no ash. To the weighed extract add water, again evaporate on the water-bath, and complete the drying in an air-bath at 110 C. In absence of other vaporizable substances the loss of weight approximates the amount of volatile oil. If the presence of a volatile alkaloid is suspected (from a characteristic odor or an alkaline reaction), add a drop of hydrochloric acid to prevent its volatilization. Camphors are partially dissipated by this treat- ment ; hence, when they are present, this evaporation should be dispensed with. Treat now the residue with a moderate amount of warm water, allow to stand until cool, then filter through fine paper by aid of a Bunsen's pump. In half of the aqueous filtrate de- termine total organic matter and ash; test the remaining half for alkaloids, glucosides, and organic acids by salts of lead, sil- ver, barium, and calcium. Care must be taken not to mistake a slight amount of suspended matter, frequently resinous, for other substances actually soluble in water. The still undissolved residue should be again removed from filters and dishes by solution in benzene, the benzene solution being again evaporated to dryness. Treat this residue with warm, very dilute hydrochloric acid, allow to cool, and filter through paper. The filtrate should be tested for alkaloids and glucosides. The amount extracted by acid, if any, may be deter- mined by weighing the still undissolved residue. Treat this re- sidue with several considerable portions of 80 per cent, alcohol (sp. gr. 0.8483 at 15.6 C.), allowing at least an hour for each treatment. Filter througn paper and determine by evaporation the matter dissolved ; this usually consists of chlorophyll with one or more resins, which may sometimes be separated by use of petroleum benzin, chloroform or similar solvents. Purified animal charcoal removes chlorophyll and some resins from alco- holic solution, while certain other resins are not removed. If camphors were present in the plant, the greater portion will be found in the alcoholic liquid. The substances undissolved by 80 per cent, alcohol may be fixed oil, solid fat, wax, and very rarely a resin; their separa- PARSONS'S METHOD. 413 tion may be attempted by refrigeration and pressure, or by use of ether, chloroform, etc. Recapitulation {portion soluble in benzene or chloroform}. 1. Loss by evaporation, with precautions : volatile oil. 2. Soluble in water : alkaloids, glucosides, organic acids. 4. f Insoluble in water. J Insoluble in acids. , 1 Soluble in 80 per cent. [ alcohol. ( Removed by animal char- a. < coal : chlorophyll, some resins. j Not removed by animal ( charcoal : some resins. ( Insoluble in water : 5. < Insoluble in dilute acids : \ Wax, fats, fixed oils. ( Insoluble in 80 per cent, alcohol : ) It is frequently advantageous to extract the plant with petro- leum benzin (sp. gr. 0.66 to 0.70, boiling at about 50 C., wholly volatile) before treatment with benzene ; by reference to the ac- companying table of comparative solubilities (p. 422) it will be seen that this treatment may serve to separate fixed and volatile oils, and some resins and colors, from certain solid fats, wax, other resins and colors. Where benzene of sufficient purity cannot be had, pure chlo- roform is the best substitute. The use of ether is objectionable in this place, as its solvent properties are less distinctly marked than are those of benzin, chloroform, and benzene; in other words, more plant constituents are sparingly soluble in ether than in the above-mentioned solvents. Consequently many sub- stances which should properly be extracted by 80 per cent, alco- hol will be sparingly dissolved if ether were used, while ben- zene, chloroform, and benzin would have no perceptible solvent action upon them; tannic acids may be cited as instances illus- trating this point. v VI. Estimation of 80 per cent. Alcohol Extract. That part of the plant not dissolved by benzene should be dried at 100 C., and then completely exhausted by 80 per cent, alcohol (sp. gr. 0.8483 at 15.6 C.) This requires from 12 to 14 hours' continuous treatment with the solvent. Remove, dry, and weigh any crystals or powder that may separate upon concentrat- ing and cooling the alcoholic percolate. Make the clear liquid 4H PLANT ANAL YSIS. to a definite volume (say 200 c.c.) by adding more 80 percent, alcohol. AN ALIQUOT PART (usually 20 c.c.) of this volume of liquid is evaporated to dryness for weight (r/i) of organic matter with ash, the residue then ignited for weight (ri) of ash, to find by difference (m n) the amount (p) of organic matter in VI. ANOTHER EQUAL ALIQUOT PART (20 c.c.) is evaporated to remove all alcohol, treated with water, filtered, and the filtrate and wash- ings evaporated to dryness to find the weight (p) of organic matter and ash that are soluble in water, the residue then ignited for weight (q) of ash that is soluble in water. Then p q = r, the amount of organic matter (in VI.) soluble in water. If the plant contain much sugar or much tannin, it will be desirable to proceed now, in separation by water, as directed further on for " the second way." Otherwise proceed in sepa- ration by absolute alcohol, in " the first way" as follows : THE REMAINING ALIQUOT PART (160 c.c.) of the clear alcoholic liquid should be evaporated carefully to dryness, the residue pulverized and treated with several considerable portions of absolute alco- hol (sp. gr. 0.7938 at 15.6 C.) A. Soluble in Absolute Alcohol (from the portion by 80$ alcohol). a. Soluble in water. a! . Precipitated by subacetate of lead. Tannin and most organic acids ; some extractives ; some inorganic acids of the ash. Weigh in Gooch's filter, ignite cautiously, and again weigh ; loss equals organic matter precipitated. a". Not precipitated by subacetate of lead. Alkaloids, glucosides, some extractives and colors. Determine weight by difference between a and a'. b. Insoluble in water. b'. Soluble in dilute hydrochloric acid. Alkaloids, glucosides (rarely), some extractives. De- termine weight by difference between b and b". b f> '. Insoluble in dilute hydrochloric acid. 1)'" . Soluble in dilute ammonium hydrate. Most acid resins, some colors. Determine weight by difference between b" and b"". 1}"" . Insoluble in dilute ammonium hydrate. Neutral resins, some colors, albuminoids (in some seeds). Eedissolve in alcohol, evaporate, and weigh. PARSONS'S METHOD. 415 B. Insoluble in Absolute Alcohol (from portion by 80$ alcohol). c. Soluble in water. c'. Precipitated ly subacetate of lead. Some colors, extractives, albuminoids (rarely), organic acids, and inorganic acids of the ash. Weigh in Gooch's filter, ignite cautiously, and again weigh ; loss equals organic matter precipitated. c". Not precipitated oy subacetate of lead. Alkaloids, glucosides, glucose, sucrose, some extrac- tives. Determine by difference between c and c'. Remove Pb by H 3 S, H 2 SO 4 , Na 2 CO 3 , or other means, and titrate for sucrose and glucose. d. Insoluble in water. d'. Soluble in dilute hydrochloric acid. Some alkaloids and glucosides. Determine by differ- ence between d and d". d". Insoluble in dilute hydrochloric acid. Few resins, some extractives and color substances. Dissolve in alcohol, evaporate, and weigh in a tared dish. " The second way": primary division of constituents in VI., by solubility in water. In some cases it may be preferable to use the following method for analysis of the 80 per cent, alcohol extract ; it is more desirable when the plant examined contains a considerable amount of sugars, tannic acid, etc. Alcohol Extract, dilute to 200 c.c. with 80 per cent, alcohol. 1. In 20 c.c. determine total organic matter and ash. Then, 2, in 20 c.c. determine total organic matter and ash that are soluble in water, and, by difference, total or- ganic matter insoluble in water, as directed in " the first way." 3. Evaporate the remaining 160 c.c. to dryness, treat with water, filter, and make the filtrate measure 160 c.c. Reserve the insoluble matter on the filter for examination (10). 4. In 20 c.c. of the aqueous solution estimate the tannin. 1 5. Precipitate 20 c.c. by normal acetate of lead, and determine, as before described, the amount of organic matter after drying at 100 to 120 C. This precipitate will contain, if the substances are present in the plant, tannic, gal- lic, and most other organic acids, some colors, rarely albuminous substances, some extractives, and most inorganic acids of the ash. Determine, by differ- ence, the amount not precipitated by this treatment. 6. In 20 c.c. determine in like manner the amount precipitated by basic acetate (" subacetate ") of lead. This reagent precipitates a greater number of acids, colors, and extractives than are precipitated by the normal acetate, hence it is frequently possible to estimate such substances by subtracting the amount precipitated by one reagent from the amount precipitated by the other. To the nitrate add a slight excess of dilute hydrochloric acid, boil gently for half an hour, and determine in the liquid total glucose by use of Fehling's solution. i For this estimation methods are given in the article on Tannins in this work. Mr. Parsons advised the gravimetric method of CABPENI (1875: Jahr. der Chem., 9^9; Chem. News, 31, 282). Precipitate by ammoniacal acetate of zinc, use a Gooch's filter, wash the precipitate with very weak ammonia, dry at 120 C., weigh, ignite cautiously, again weigh. The loss by ignition equals tannic acid, in absence of certain interfering substances. 416 PLANT ANAL YSIS. 7. Precipitate 20 c.c. by subacetate, exactly as in 6, and use the precipitate as a duplicate to check the amount there estimated. To the filtrate add a very slight excess of solution of carbonate of sodium, filter from the carbonate of lead, wash well with water containing a little alcohol, and in the filtrate esti- mate actual glucose. If the glucose thus found is appreciably less than that in 6, subtract it from that amount; this glucose maybe due to the presence in the plant of sucrose or some gluconide. If due to sucrose, the amount of the latter may be found by multiplying this residual glucose by 0.95; if to a glucoside, a fit subject for an extended investigation is presented. The properties, formula, and decomposition products of the newly found glucoside should be carefully studied. 8. Precipitate 20 c.c. with subacetate of lead, as in 6 and 7, employing the Erecipitate as material from which to separate organic acids, after removal of jad by sulphuretted hydrogen. Acidulate the filtrate with sulphuric acid, add an equal volume of alcohol, allow to stand two hours, filter, wash the precipi- tate with 50 per cent, alcohol, and evaporate the filtrate until all alcohol has been dissipated. Test the acid solution for alkaloids, glucosides, sugars, ex- tractives. 9. Reserve the remaining 40 c.c. for duplicating any unsatisfactory deter- minations. 10. The residue mentioned in 3 as insoluble in water may contain resins, albuminoids (especially from seeds), colors, alkaloids, glucosides. Dilute acids remove alkaloids and some glucosides; dilute ammonia water will remove some resins, colors, and glucosides. Any still insoluble residue probably con- tains albuminous or resinous substances. VII. Estimation of Cold Water Extract. That part of the plant remaining insoluble after treatment with alcohol should be dried at 110 C. and completely extract- ed by cold water. When the plant contains considerable mu- cilaginous matter this is best removed by placing the sub- stance in a flask or graduated cylinder, and then adding a mea- sured volume of cold water. Allow to macerate, with frequent agitation, for from 6 to 12 hours, then filter through fine washed linen, and evaporate an aliquot portion of the solution. In this residue determine total organic matter and ash. This residue usually contains little but gum ; in analysis of fruits and fleshy roots, pectin bodies, salts of organic acids, rarely a substance re- sembling dextrin, and small amounts of albuminous substances and coloring matter. Usually the separation of these substances is very difficult. The unevaporated liquid should be used for such qualitative reactions as are necessary to show the nature of the substances extracted. The insoluble residue should be well washed with water, transferred to a crucible, and completely dried at 110 C. This residue should then be weighed. VIII. Estimation of Acid Extracts. The dried residue insoluble in cold water should be trans- ferred to a beaker containing 500 c.c. of water and 5 c.c. of con- centrated sulphuric acid (sp. gr. 1.84). Boil for 6 hours on a PARSONS'S METHOD. 417 gauze support, adding water to keep the volume of liquid un- changed ; if the substance be very starchy a longer boiling may be necessary. This treatment will convert starch and its amor- phous isomers to dextro-glucose, and will occasionally remove some salt of an organic acid, with usually traces of albuminous and indeterminate substances. The total amount extracted may be found by washing, drying at 110 0., and weighing the yet insoluble residue, and subtract- ing the weight from the one taken after extracting with cold water. The amount of starch and isomers may be found by determining in a given volume of the acid filtrate the amount of glucose, using Fehling's solution ; the glucose thus found multi- plied by 0.9 equals starch and isomers. The total extract minus starch and isomers equals acid extract not starch. This includes a small amount of ash, which may be approximately determined by evaporating and igniting a known volume of the solution. Where it is wished to separate the extracted matter from the sulphuric acid, boil the liquid with an excess of powdered barium carbonate until no acid reaction remains. Filter and evaporate to dryness. The residue consists chiefly of hydrated dextro- glucose (C 6 H 13 O 6 .H 2 O), with some ash. IX. Estimation of Alkali Extract. Wash well and dry at 110 C. the residue from treatment with acid, and record its weight. Boil this residue for two hours with 500 c.c. of a solution containing 20 grams of sodium hydrate to the liter. Filter through fine washed linen, and wash the residue thoroughly with hot water, alcohol, and ether. Transfer it to a weighed crucible, dry at 110 to 120 C., and weigh the residue as crude fibre and ash ; this weight subtracted from ^the previous one shows the total alkali extract. This ex- tract ^ is largely albuminous matter and various modifications of pectic acid, Fremy's " cutose" and various coloring, humus, and decomposition compounds, in small amounts. Most of the ex- tracted substances may be precipitated by excess of an acid with or without the presence of alcohol. X. Cellulose. The crude fibre from IX. should be treated with from 50 to 100 c.c. of U. S. Ph. solution of chlorinated soda and allowed to stand twenty-four hours. If not then bleached white, slightly acidulate with hydrochloric acid and set aside for another day. Filter through fine linen or Gooch's filter, wash with hot water, 4i8 PLANT ANALYSIS. dry at 110 to 120 C., and weigh, ash-free, as cellulose. The loss of weight by this treatment state as lignose and color. Recapitulation of Parsons '$ Method. I. Sampling, pulverization, and preservation of an air-dry portion in constant condition for an analysis. II. Estimation of moisture by loss at 100-120 C. III. Estimation of Ash. a. Portion of the ash soluble in water. . Insoluble in water; soluble in dilute hydrochloric acid. c. Insoluble in water or in the acid ; soluble in sodium hydrate solution. IV. Estimation of the total nitrogen. For check on results ; for calculation of albuminoids after estimation of alkaloids, etc. V. ESTIMATION OF PORTION SOLUBLE IN BENZENE (OR CHLORO- FORM). 1. Portion of benzene extract vaporized with benzene : volatile oils (camphors). 2. Portion of benzene extract soluble in water : alka- loids, glucosides, organic acids. o j Not soluble in water, [ Alkaloids, possibly glu- ' \ soluble in dilute acid : f , co sides. Removed by animal ( Not soluble in water 4. resins. JNot soluble in water or the acid, or in al- \- Waxes, fats, fixed oils. x cohol of 80^ : ) VI. ESTIMATION OF PORTION SOLUBLE IN ALCOHOL OF 80$ (after removal of V.) The solution is made up to a defi- nite volume (200 c.c.) IN TWO EQUAL ALIQUOT PARTS (20 c.c. each) residues are obtained to furnish (1) the amount of organic matter, (2) the amount of organic matter soluble in water, thence the amount of or- ganic matter insoluble in water. IN " THE FIRST WAY " the constituents of VI., in the re- maining 160 c.c., are primarily divided according to their solubility in absolute alcohol, then by further treatment, as follows : PAXSOMS'S METHOD. 419 A. Soluble in absolute alcohol. a. Soluble in water. Weight obtained. of. Precipitated by subacetate of lead. Tannin and most organic acids; some ex- tractives; some inorganic acids of the ash. Weight of all obtained. a,". Not precipitated by subacetate of lead. Alkalouh, glucosides, extractives, colors. a a' = a". l>. Insoluble in water. Weight obtained. I' '. Soluble in dilute hydrochloric acid. Alkaloids, rarely glucosides, extractives. I -I" = V. "b" . Insoluble in dilute hydrochloric. Weight taken. ~b'" . Soluble in dilute ammonium hydrate. Most acid resins, some colors. I" _ I"" - l">. I)"" . Insoluble in the ammonia. Weight taken. Neutral resins, some colors, albuminoids. B. Insoluble in absolute alcohol. c. Soluble in water. c'. Precipitated by subacetate of lead. Colors, extractives, rarely albuminoids, organic and inorganic acids. Weigh. c". Not precipitated by subacetate of lead. Alkaloids, glucosides, glucose, sucrose, extrac- tives. c c' = c" . Estimate sugars. d. Insoluble in water. d f . Soluble in dilute hydrochloric acid. Alkaloids, glucosides. d d" =. d 1 . d" . Insoluble in dilute hydrochloric acid. Few resins, extractives, colors. Weigh. IN " THE SECOND WAY" the constituents of VI., taken in the remaining 160 c.c. of 80$ alcohol solution, are pri- marily divided according to their solubility in water, then by other treatment, as follows : (3) Evaporate to dry ness, add water, reserve the residue (10), and make the filtrate up to 160 c.c. (4) In 20 c.c. estimate tannin. (5) In 20 c.c. estimate total precipitate by lead normal acetate. Tannins, odds (inorganic and organic), colors, extractives. 420 PLANT ANAL YSIS. (6) In 20 c.c. estimate total precipitate by lead basic acetate. Compare precipitate with that in (5). In filtrate estimate the total glucose of sugars and glucosides. (7) In 20 c.c. duplicate the precipitation of (6). In filtrate estimate the actual glucose. Compare with total glucose. (8) In 20 c.c. triplicate the precipitation of (6). Ex- amine the precipitate for alkaloids, glucosides, sugars, extractives. (9) Use the remaining 40 c.c. for additional exami- nations. (10) The residue left in operation 3 may be tested for resins, albuminoids, colors, alkaloids, gluco- VII. ESTIMATION OF THE PORTION SOLUBLE IN COLD WATER (after removal of V. and VI.) Examine as directed in the text, making up the filtrate to a definite volume, and taking aliquot parts (1, 2, 3, 4, etc.) for determina- tions and tests. In (1) determine total solids, and then the ash, to find the total organic substances. Gums, pectous substances, salts of organic acids, dextrins, soluble starches, albumens, colors. Examine by solubilities, iodine test, estimation of nitrogen, etc. The residue from solution VII., dried at 110 C., is weighed. VIII. ESTIMATION OF PORTION SOLUBLE IN BOILING DILUTE ACID (after removal of V.,VL, and VII.) The weight of the washed residue obtained for estimation of the total solids of VIII. Starches estimated by determination of glucose with Fehling's solution, first examining for interfering extractives of a reduc- ing power. An aliquot portion of the liquid, freed from the sulphuric acid, is tested in portions quali- tatively. Small amounts of albuminoids may be found. IX. ESTIMATION OF PORTION SOLUBLE IN ALKALI-WATER (after removal of portions V. to VIII.) Take weight of insoluble washed residue, for estimation of total sol- ids. Album,ens, forms of pectin, humus, decomposi- tion products, colors. X. ESTIMATION OF THE RESIDUE LEFT BY SOLVENTS V. to IX. Cellulose, lignose, colors, ash. Estimate from sepa- ration by chlorinated soda solution. PARSONS'S METHOD. 421 Remarks. 1 It is advisable to determine always, in addition to what has already been directed, the amounts extracted directly from the sample by water, ether, alcohol of various percentages, methyl alcohol, benzin, chloroform, carbon disulphide, etc. In each extract estimate total organic matter and ash, and determine qualitatively, and quantitatively when possible, its constituents, by treating with such solvents and reagents as are indicated. Each extract being com- posed of certain distinct substances, it is necessary to account for them in every case. The amounts present of some constituents may be found by subtracting the weight extracted by some one solvent from the weight extracted by some other. It will be seen that this is a'method of limited applicability, which can only be applied in those cases where the difference between the solvent action of the two liquids is very sharply defined. Certain special methods for the esti- mation of single constituents may be used, care being taken that all interfering substances be first removed. The methods of preparation of known substances as given in HUSEMAXX'S " Pflanzenstoffe," and to a considerable extent in 4 ' Watts's Dictionary," may serve as suggestions for work. Treatment with ben- zene, 80 per cent, alcohol, and water, removes from nearly all plants the con- stituents of greatest chemical and medicinal interest, but in analyses of grains, fodder, and food materials, those compounds extracted by dilute acids and alka- lies have great value. There are substances in plants, seemingly isomers of starch and cellulose, which have properties more or less resembling those of cellulose, and are changed by boiling with dilute acids to glucose. In absence of an established nomenclature it has seemed best to use the terms "starch isomers" or "amylaceous cellulose" for these substances, 2 while those consti- tuents, not albuminous which are removed by dilute alkali have been termed "alkali extract." These substances have been investigated by various chemists, but no definite and authoritative nomenclature has yet been adopted. THOM- SEN gives the name " holz-gummi," 3 wood-gum, to a white substance extracted from plants by dilute sodium hydrate, while FREMY regarded these various com- pounds as modifications of pectic acid, pectin, and "cellulose bodies." 4 Starch also may exist in some seeds (as of sweet corn) in a form soluble in water. 5 It will be seen that the field for investigation is limitless, and that there is great need for improved methods for proximate analysis. The analyst will find that a study of any common plant will require of him much more than unthinking, mechanical habits of manipulation, while every careful investi- gation will reveal to him some constituents deserving more full and accurate study. 1 By Henry B. Parsons. 3 U. S. Dept. of Agric. Report, 1878, p. 189. z Jour. prak. Cbcm., IQ, 146. 4 Compt. rend.. 83. 1136: Jour. Mem. Soc.. 31, 229(1877). 5 U. S. Dept, of Agric. Report, 1878, pp. 153-155. 422 PLANT ANALYSIS. i^*8 s. : ; : : . : :'^-^ r ^ r ^ ."o' .o T3 1 O I i */'*" : : : _ : : ' rr; ; r i ""I ^~ . .~..... nidne :::::::::::::::::: i* e * * :: * -omoMtttfp #JW0M#^ ^MOUMOI D ^^"^ fit' "5 W ce3 ^.5 > 5 co^j-^'&owa'tftcoyJsoGOi/itoGOcoco pC i~ r c'o 2** " _ rii r- ra _ _ r _ __ _ i'SajS ci c.'S "3 'S "S 2 ?2 JS'S'S 2" S S g'6'd .S^- , I'll^ s'1.1 ev. c'5 g g iifl 111! *cJ 'B ' o C . o ^_ '^oa-i-^w.SaQop j a ca'S Oja 3 fjct C ? DRA GENDORFF'S ME THOD. 423 OUTLINE OF DRAGENDORFF' s METHOD OF PLANT ANALYSIS.' For the systematic analysis 30 to 50 grams may usually be taken. From 2 to 5 grams are dried at 100-110 for total moisture ; and usually another portion, not above 30 C., for amount of loss. The material for the systematic analysis to be powdered, sampled, mixed, and very finely pulverized for sol- vents. Very hard bodies are dried at 100 to 110 C. before pulverizing Fatty bodies may be first treated with the petroleum benzin. For ignition pulverize very fine, and if need be, after partial ignition, pulverize again. To promote combustion am- monium nitrate may be added,, or ignited and weighed ferric ox- ide may be introduced. Powdered glass or washed sand may be intermixed. The carbon dioxide of the ash is to be determined. Special methods are used for the full quantitative estimations of distinct substances. I. SOLUTION BY PETROLEUM BENZIN (petroleum-ether, petrole- um spirit). This solvent to boil to the last at 45 C. and leave no residue. Use 10 c.c. for each grain of the dry plant pow- der. Macerate eight days, shaking daily. Aromatic fresh plants may be treated, without previous drying, by fine division, and by percolation with the solvent. Receive in a graduated separator, and take off aliquot volumes for examination and for weight of total dissolved substances. To evaporate the solvent from essential oils and other vola- tile matters, almost without waste of the latter, place 2 the solu- tion in a small, shallow dish, which is to be set within a wide- mouthed jar, this being so connected that a current of dried air is drawn over the surface of the solution. The air is drawn through chloride of calcium tubes, one of which is placed before and one beyond the jar containing the solution, so that there can be no backward diffusion of moist air. The jar is closed air- tight by a stopper admitting entrance and discharge tubes, the entrance tube reaching nearly to the surface of the benzin solu- tion. The air is drawn at the desired rate by an aspirator, one acting by the discharge of water from a large closed bottle or jar. ' References to publication of Dragendorff 's work are given on p. 407. This outline is by no means a substitute for Dr. Dragendorff s book on the chemistry and analysis of plants. But the outline of his plan of separations is presented for the convenience of a compact form, and as suggestion for instituting various analytical operations on vegetable tissues. 2 This method of evaporation in a current of dry air was used by OSSE, who reports control-analyses by it, 1876: Archiv d. Phar. [3] 7, 104; Jour, Chem. Soc., 29, 759; Dragendorff's " Plant Anal.," by Greenish, p. 21. 424 PLANT ANALYSIS. Fats may be treated with alcohol and observed with the microscope. 1 Glycerides may be saponified for separation [see pp. 274, 265, etc.] Alkaloids subjected to general tests [pp. 33, 42, 53]. Ethereal oils tested by solubilities, sensible properties, re- actions. Volatile acids recognized by acidity or by forming salts. Chlorophyll, by optical examination. 3 II. SOLUTION BY ETHEK. This solvent to be prepared as nearly as possible free from alcohol and from water (so as not to take up tannin). It is applied to the drug or vegetable matter previously exhausted by petroleum benzin, washed with the lat- ter, and dried. For 1 gram use 5 to 10 c.c. of the ether. Ma- cerate in a graduated cylinder seven or eight days. Take off aliquot volumes for examination. Evaporate the ether by a current of dried air, as directed for the benzin. Test portions by solubilities in (a) water, (b) alcohol (absolute), (c) alkali. The ether-soluble portion may contain bensoic, salicylic, and gal- lic acids, salicin and other glucosides, alkaloids, resins, hema- toxylin, etc. For estimation of total ether-soluble fixed sub- stances an aliquot part is evaporated and dried at 110 C. [Fur- ther see the articles Alkaloids, Benzoic Acid, etc. Resins are found in the part insoluble in water. Compare p. 278.] III. SOLUTION BY ABSOLUTE ALCOHOL (following solvents I., II.) For 1 gram of the material 10 c.c. of the sol vent. Macerate five to seven days, restoring loss, then filtering through paper wet with alcohol. Evaporate an aliquot volume, arid dry at 110 C. for weight. Evaporate other portions, without heat, in vacuum, and dry over sulphuric acid. A residue, obtained as last directed, is to be treated with water, in measured proportion, filtered, the filtrate evaporated to constant weight at 110 C., for weight of all water-soluble matters in III. Other portions of the aqueous solution are taken for the estimation of tannins and for sugars. A portion of the residue (III.), undissolved by water, is gently dried and treated with ammonia water dilute (1 : 50), the ammonia solution acidulated with acetic acid, and the precipitate, if any, after concentration, examined fer phlobaphene, which may be estimated in this way [see Phlobaphene, under Tannins]. Por- tion III. may contain resins, alkaloids, glucosides, bitter prin- ciples. 1 See HEINTZ: Ann. Phys. Chem. (Pogg.), 92, 588; Phar. Jour. Trans. [1] 15, 425. GREENISH: Phar. Jour. Trans. \3] 10, 909. This work, p. 297. 8 Dragendorff, English ed., p. 19. DRAGENDORFFS METHOD. 425 The water-soluble portions of II. (the ether -extract) and of III. (the alcohol-extract) may be treated by immiscible solvents, applied first to the watery liquids made acidulous with sulphuric acid, and then applied to the same liquids made ammoniacal with ammonia. [See this work, pages 33 and after ; and the author's " Outlines of Proximate Organic Analysis," p. 136.] As immis- cible solvents, petroleum benzin, benzene (boiling constant at 81 C.), and chloroform are recommended. The following re- sults are indicated : By petroleum benzin from acid solution Absinthin, Capsicum, Hop bitter, Piperin, Salicylic acid. By benzene from acid solution - Absinthin, Berberine, Caffeine, Caryophyllin, Cascarillin, Colchicine, Colocynthin, Cubebin, Daphnin, Elaterin, Ericolin, Gratiolin, Menyanthin, Populin, Quassin, Santonin. By chloroform from acid solution ^Es- culin, Benzoic acid, Cinchonine, Colchicine, Convallamarin, Di- gitalein, Helleborin, Narceine, Physalin, Picrotoxin, Quinidine, Theobromine, Saponiu, Senegin, Solanidin, Syringin. (Before making alkaline, the dissolved chloroform is washed out with a little petroleum benzin.) By petroleum benzin from alkaline aqueous solution Brucine, Capsicum, Conine, Emetine, Lobe- line, Morphine, Nicotine, Sabadilline, Sabatrine, Sparteine, Strychnine (traces), Trimethylamine. By benzene from alka- line solution Aconitine, Atropine, Cinchonine (traces), Co- deine, Delphinine, Gelsemine, Hyoscyamine, Physostigmine, Pilocarpine, Narcotine, Quinidine, Taxine. By chloroform from alkaline solution Cinchonine, Morphine (traces), Papa- verine, Narceine. By amyl alcohol from alkaline aqueous so- lution (following previous solvents) Morphine, Salicin, Sola- nine. [Tests for a glucoside, by fermentation, are indicated in the article Tannins in this work. Estimation of alkaloids, p. 44, and under the several alkaloids.] IV. SOLUTION IN WATER. The residue insoluble in absolute alcohol (III.) is dried and treated with 10 parts of water, by 48 hours' digestion, then filtered through the filter previously used. The filter should be washed with water, and the washings exam- ined separately. An aliquot volume (10 to 20 c.c.) of the fil- trate is evaporated, and dried at 110 C., for weight of total sub- stances in IV. To another aliquot portion, 10 to 20 c.c., add 2 c.c. absolute alcohol, leave 24 hours in a cool place, filter on a tared filter, wash with 66$ alcohol, dry, and weigh. Find the weight of ash in each of the two portions last weighed. In IV. may be found pectous substances, albumens, inulin, dextrines, sugars, acids, saponin. A precipitate by lend acetate will 426 PTOMAINES. contain the acids, with mineral acids. Sugars here are to be estimated. A portion, before and after obtaining IV., may be subjected to estimation of nitrogen, when consideration is given to the presence of ammoniacal salts, amides, alkaloids, nitrates, etc. (Dragendorff, paragraph 97). Albumen is estimated by pre- cipitation with tannin or from the amount of nitrogen. Y. SOLUTION IN ALKALI WATER. For 1 part residue not dis- solved in IY. take 10 parts of a 0.1 to 0.2$ solution of sodium hydrate. Macerate 24 hours. Filter an aliquot volume, satu- rate* with acetic acid, add alcohol of 90$, leave 24 hours in the cold. Collect the precipitate on a tared filter, wash with 75$ alcohol, dry, and weigh. Ignite and weigh the ash. Al- bumens and pectous substances are contained. The residue insoluble in alkali is apt still to retain traces of nitrogen com- pounds. YI. SOLUTION IN ACIDULATED WATER (after removal of I. to Y.) The residue not soluble in Y., washed, is treated with a 1$ solution of hydrochloric acid. It is found by a microscopic examination of the original material, whether it contains starch or not. Oxalate of calcium may be separated and estimated, digesting with the acid for 24 hours at 30 C. In a measured quantity of the liquid, neutralize with ammonia, add acetate of sodium to react with all the hydrochloric acid, and set aside for the calcium oxalate to form, for gravimetric determination (as calcium carbonate). VII. THE INSOLUBLE RESIDUE from VI. is washed, dried, and weighed. Treated with chlorine, and weight of residue found, the difference represents lignin and incrusting substances ; the remainder contains the cellulose, which is examined microsco- pically, and the ash. PROTOPINE. See OPIUM ALKALOIDS, p. 360. PSEUDACONITINE. See ACONITE ALKALOIDS, p. 19. PSEUDOMORPHINE. See p. 359. PTOMAINES. Cadaveric Alkaloids. Ptomaine. Alka- loid-like bodies formed in the putrefactive decomposition of animal tissues. The formation may commence shortly after death. It may be caused or promoted by digestion with acids (COPPOLA, 1885), especially when the mixtures are acidulated with sulphuric acid. BRIEGER (1885) enumerates the following products of the putrefaction of the human body : PTOMAINES. 427 Choline, C 5 H 15 NO 2 . Neuridine, C 5 H 14 N 2 . Cadaverine, C 5 H 16 N 2 , boiling at 115-120 C., with water at 100 C. Putrescine, C 4 H 1Q N 2 , boiling at about 135 Og Saprine, C 5 H 16 N 2 . Trimethyla 5 mme,C 3 H 9 N. Mydalein. A ptomaine boiling at 284 C. Of the above, only Choline is poisonous. From putrefactive albumen and gelatine Brieger (1885) had obtained : Neurine, C 5 H 13 NO. Muscarine, C 5 H 15 NO 3 . An ethylenediamine, C 2 H 4 (H 2 N) 2 . Neuridine, C 5 H 14 N 2 . Gadiiiine, C 7 H 17 KO 2 . Triethylamine, dimethylamine, and trimethylamine. Of these the first three named are extremely poisonous. The greater number of cadaveric ptomaines are non-poisonous. Concerning their chemical constitution, Brieger (1885) calls attention to the fact that most of the characteristic ptomaines are diamines ; that they are chemically more simple in composition than are the vegetable alkaloids ; that many of the ptomaines are derivatives of hydrocarbons of the ethylene series, and are in distinction from true alkaloids representing the pyridine group. Ptomaines are for the most part obtained from tissues in the operations of separation by the immiscible solvents. In evapo- rations they are liable, in part, to be vaporized. They are easily decomposed and are affected by atmospheric oxidation. They respond to the greater number of the general reagents for preci- pitation of alkaloids. Cadaverine hydrochloride, C 5 H 16 N 2 .2HC], gives reactions as follows (BRIEGER, 1885): With phosphomolybdic acid, a white crystalline precipitate. With iodide of potassium, or with iodine in iodide solution, brown needles ; with potassium bismuth iodide, reddish needles; with picric acid, yellow needles; with potas- sium chromate and concentrated sulphuric acid, a red-brown pre- cipitate, soon vanishing. Free cadaverine gives with potassium mercuric iodide a resinous precipitate ; with potassium iodide, a brown precipitate ; with tannic acid, a white precipitate. Free or in salt it promptly reduces a mixture of ferric chloride and potassium ferri cyanide, giving a blue color. 428 PTOMAINES. Putrescine hydrochloride, C 4 H 12 N 2 . 2HC1, with phosphomo- lybdic acid gives a yellow precipitate ; with potassium mercuric iodide, an amorphous precipitate soon crystallizing in needles ; with iodide of potassium, or iodine in iodide solution, a brown crystalline precipitate. Ptomaines are mostly quite strong reducing agents, and the reaction of ptomaine sulphates with ferric chloride and potas- sium ferricyanide (BROUARDEL and BOUTMY, 1881) has been an nounced as characteristic of the animal alkaloids, but this is not admitted by Brieger. The latter states that the reduction of the ferricyanide mixture, with formation of a blue color, is obtained by cadaverine, saprine, mydaleine, and some other ptomaines, not by choline, neuridine, or putrescine. Brieger further states that he has not found a distinctive reaction for ptomaines. They are all precipitated by phosphomolybdic acid, a reaction they share with ammonia, as well as with the vegetable alkaloids (p. 46). The reduction of ferricyanide with ferric salt, forming prussian blue, is not given promptly by many vegetable alka- loids, but is given at once by morphine and veratrine (Brouardel and Boutmy), at once by colchicine (Beckurts, 1882), and is given slowly and feebly by aconitine, brucine, conine, digitaline, nicotine, strychnine, papaverine, narceine, codeine (Beckurts). LEUCOMAINES. Animal alkaloids, more or less septic, formed in tissues and organs of the living body : Xanthocreatinine, CgH-^lN^O. From muscular tissue. Ee- sembles creatinine. Cruscocreatinine, C 5 H 8 1S" 4 O . . Eesembles creatinine. Amphicreatinine, C 9 H 19 N 7 O 4 . Pseudoxanthine, C 4 H 5 N 5 O . . . Eesembles xanthine. Mytilbtoxine, C 6 H 15 NO 2 From mussels ; poisonous. Betaine, C 5 H n NO 2 From mussels; non-poisonous. The first four above given were found by GAUTIER (1886) ; the last two by BRIEGER (1886). Neurine was obtained by MARINO-ZUCO (1885) from fresh eggs, blood, brains, liver, etc., by the method of Stas, and more abundantly by the method of Dragendorff, and formed from the lecithin of the tissues by action of acids on them, not formed from the albuminoids. These leucomaines mask the reactions for the vegetable alkaloids. By repeatedly extracting (shaking out) from alkaline solution, with ether or chloroform, it was found that the neurine was left behind. From the liver and spleen, in addition to neurine, a violet fluorescent base was obtained. PTOMAINES. 429 Respecting cheese-poison, reported upon by VICTOR C. YAUGHAN in 1884 as a poisonous ptomaine, and now announced by him as diazobenzene salts, see Tyrotoxicon, in this work. The literature of ptomaines and leucomaines is mainly embraced in that of physiological and pathological chemistry. Among the publications of interest in analytical chemistry and toxicology, an index is here made of the following : DUPRE and BENCE JONES, 1866 : Respecting a frail alkaloid-like body found in the organs and liquids of the bodies of man and of animals, Zeitsch. Chem. und Phar., 1866 ; Phar. Centralh., 16 ; Ber. d. chem. Ges., 7, 1491. SONNENSCHEIN and ZULZER, 1869 : On bases obtained from mus- cular tissue, Berlin klin. Wochenschr., 1869, 123. RORSCH and FASSBANDER, 1871 : On a body giving reactions for alkaloids, found in analyses of liver, etc., for poisons, Ber. d. chem. Ges., 7, 1064. SELMI, chiefly about 1878 : On toxicology, 1876, Gazzetta chim. ital., 4, 1 ; Jour. Chem. Soc., 27, 607. On alkaloids of cada- veric putrefactions, 1873 to 1880 : Ber. d. chem. Ges., 6, 142; 8, 1198; 9, 195; II, 808, 1838; 12, 279; 13, 206. 4 ' Sulle Ptomaine ad alkaloidi cadaverici," Bologna, 1878. On alkaloids in the cadaver, 1879, Gazzetta chim. ital., 9, 35 ; Jour. Chem. Soc., 36, 734. On a poisonous alkaloid from a cadaver containing arsenic, 1 879 : Gazzetta chim. ital., 9, 33; Jour. Chem. Soc., 36, 734. On an alkaloid found in the brain and liver, and in the wild poppy, 1876, Gazzetta chim. ital., 5, 398 ; Jour. Chem. Soc., 29, 938. On pathological bases, 1881, Gazzetta chitn. ital., 1881, 546; Jour. Chem. Soc., 42, 741. TH. HUSEMANN, 1881 : The ptomaines in toxicology, Archiv der Phar. [3] 16, 415 ; Am. Jour. Phar., 54, 152. H. BECKURTS, 1882 : Distinctions between cadaver and plant al- kaloids, Archiv der Phar. [3] 17, 104 ; Am. Jour. Phar., 54, 221. Zeitsch. anal. Chem., 24, 485. BROUARDEL and BOUTMY, 1881: Distinctive reactions of pto- maines, Ber. d. chem. Ges., 14, 1293; Compt. rend., 92, 1056. MARINO-ZUCO, 1884 : Ptomaines in toxicology, Gazzetta chim. ital., 13, 431, 441 ; Jour. Chem. Soc., 46, 342, 343. ARNOLD, 1884 : Ptomaines in toxicology, Archiv der Phar. [3] 21, 435 ; Jour. Chem. Soc., 46, 469. GARNIER, 1883 : Ptomaines in toxicology, Jour, de Phar., 7> 377 ; Am. Jour. Phar., 55, 404. L. BRIEGER, Berlin, 1884-87 : " Ueber Ptomaine," Berlin, 1885. 430 PYROGALLOL. Zieitsch. physiolog. Chem., 3, 135 ; 9, 1. " Weitere Unter- suchungen iiber Ptomaine," Berlin, 1885-86. Ber. d. chem. Ges., 17, 2741 ; Zeitsch. anal. Chem., 24, 484. A new pto- maine producing tetanus, Ber. d. chem. Ges., 19, 3119 ; Jour. Chem. Soc., 52, 284. MAAS and others, 1884: Ptomaines in boiled meat, Chem. Cent., 1884, 975 ; Jour. Chem. Soc., 48, 676. Y. C. YAUGHAN, 1884-85 : A ptomaine from poisonous cheese, Zeitsch. physiolog. Chem., 10, 146; Jour. Chem. Soc., 50, 373. Michigan State Board of Health Reports. (See " Ty- rotoxicon," in this work.) COPPOLI, 1885 : Ptomaines formed by processes of analysis of tissues for poisons, Gazzetta chim. ital., 14, 124, 571; Jour. Chem. Soc., 48, 278, 913. GAUTIER, 1885-86 : Leucomaines, Bull. Soc. Chim., 43, 158 ; Jour. Chem. Soc., 48, 676. On alkaloids of bacterial origin, etc., Paris, 1886. Ptomaines and Leucomaines, 1886, Jour. Phar. [5] 13, 354; Jour. Chem. Soc.,50, 634. LADENBURG, 1885 : Ber. d. chem. Ges., 18, 2956, 3100. OLIVERI, 1886 : Supposed ptomaines of cholera, Gazzetta chim. ital., 16, 256 ; Jour. Chem. Soc., 50, 1049. PURPURINE. See COLORING MATERIALS, p. 190. PURPUROGALLIN. See p. 431. PYROGALLOL. C 6 H 6 O 3 = C 6 H 3 (OH) 3 = 126. Pyro- gallic Acid. Manufactured from gallic acid or from gallo tan- nin by sublimation. One part of gallic acid with two parts of powdered pumice stone may be heated to 210-220C. in a stream of carbon dioxide. To obtain colorless, sublimed in a vacuum at 210 C. Used as a reducing agent in photography ; also to a limited extent in hair dyes, either by itself or to reduce silver. Pyrogallol is identified by its reactions with alkalies and iron salts, and its formation of purpurogallin. It is separated from tannic acid by its not precipitating with gelatin. It may be estimated in a lead compound. Pyrogallol crystallizes in lustrous plates or needles of white or yellowish- white color, a very bitter taste, without odor, and a neutral or very feebly acidulous reaction. It gives a brown color to the skin. The crystals are changeless in dry, pure air, dark- ening in ammoniacal air. It melts at 115 C., boils at 210 C., PYROGALLOL. 431 and at about 250 C. blackens- with production of metagallic acid. (See Gallic Acid, p. 321.) It dissolves in three parts of water, freely in alcohol and in ether, not in absolute chloroform. The watery solution darkens on standing, sooner if heated, quickly coloring by addition of alkalies, with formation of alkali carbonate and acetate, absorption of oxygen taking place to an extent pro- portional to the coloration, which is destroyed by oxalic acid. The alkalies cause reddish-yellow to red-brown tints ; lime solu- tion, a violet to purple color ; all becoming gradually brown to black. Ferroso- ferric salts, slightly oxidized ferrous salts the better, give a clear blue color. If there be much ferric salt the color soon turns to red, and with ferric salt alone the color is reddish at first. If the very dilute solution of ferric salt and pyrogallol be gradually treated with ammonia, the color changes first from red to blue, and then back to bright red. (The reaction is like that of purpurogallin, given below.) By gradually adding then acetic acid or other organic acid, the blue is first restored, then a red color again appears. Hydrochloric acid and most inorganic acids give at once a red color. The blue color is produced by bicarbonates as well as by ammonia, 1 also by free alkaloids (SCHLAGDENHAUFFEN). In presence of gum arable, blood, saliva, and various other organic substances, pyrogallol, in solution, exposed to the air, gradually forms PUKPUKOGALLIN, C 20 H 16 O 9 (STRUVE). The same product is obtained at once by adding a strong solution of permanganate acidulated with sulphuric acid. Purpurogallin has a red color of much intensity, imparted to solutions, from which it crystallizes in yellow to red needles, and by sublimation is obtained in garnet-red crystals. It is sparingly soluble in water, and its solution, with an alkali, gives a transient blue color of great intensity. 8 Pyrogallol is a most forcible reducing agent, promptly re- ducing salts of silver and mercury, and Fehling's solution, and reducing ferric salts in the iron reactions above given. It is 'JACQUEMiN, 1874 and 1876-77: Ann. CMm. Phys. [4] 30, 566; Jour. Chem. Soc., 27, 1016; Jour. Chem. Soc., 31, 340. A very dilute solution of ferric chloride and pyrogallol is used as an indicator, more delicate than litmus, for the estimation of ammonia or of bicarbonates (as in mineral waters). The solution is made of equal volumes of a solution of 5 grams pyrogallol to the liter, and a solution of 2 grams ferric chloride to the liter. It deposits purpu- rogallin, and needs to be filtered from time to time. Of the solution 10 c.c. are added to 250 c.c. of water for alkalimetry. 5 As to ethers of pyrogallol, and their color products, see " Watts's Diet.," viii. 1710. Pyrogalloquinone, ibid. 1713. Reaction with mercuric chloride and alkaloids, ibid. 1709. 432 RACE MIC ACID. attacked by nitric acid, with red products. Its dry mixtures with many oxidizing agents are explosive. In aqueous solution, with alkali, it removes nearly all the oxygen from a confined portion of air. A gravimetric estimation may be made by adding to an alcoholic solution of pyrogallol an alcoholic solution of lead acetate, faintly acidulated with acetic acid, quickly washing the precipitate with alcohol, drying on a water-bath, and weighing. Pb(C 6 H 5 3 ) 2 : 2C 6 H 6 3 :: 457 : 252 :: 1 : 0.5514. QUINAMINE. See CINCHONA ALKALOIDS, p. 92. QUINICINE. See p. 94. QUINIDINE. See p. 154. QUININE. See p. 125. QUINOIDINE. See p. 94. QUINOLINE. See p. 165. QUINOLINE RED. See COLORING MATERIALS, p. 182. RACEMIC ACID. H 2 C 4 H 4 O 6 i=150. Paratartaric Acid. Traubensaure. Separable Inactive Tartaric Acid. An isomer of tartaric acid, found in some varieties of grapes, and differing from dextrotartaric acid in the form of crystallization, in optical powers, and in its solubilities as free acid and as calcium salt. It crystallizes in the triclinic system, with one molecule of water, becoming anhydrous at 100 C. It is soluble in about 5 parts of cold water and in 48 parts alcohol of 0. 809 specific gravity. Its solution is optically inactive, not rotating the plane of polarized light, but it is separable into dextrotartaric and levotartaric acids, as follows : When the racemates of two bases, as sodium and ammonium, in molecular proportions, are crystallized from solu- tion together, crystals of a double salt, as S~aNH 4 C 4 H 4 O 6 , are obtained, and these crystals, rectangular prisms, have certain hemihedral faces, and are divided into pairs, right and left, by the position of the hemihedral faces. The one crystal of a pair coincides with the reflection of the other from a mirror. When the two kinds of crystals are separated by hand-picking, the one kind is found to be the salt of dextrotartaric acid, identical with ordinary tartaric acid, while the other kind is a salt of another SALICYLIC ACID. 455 tartaric acid isomer, whose solution rotates the light plane to the left, and is termed Levotartaric Acid, or anti tartaric acid. Racemic acid, free, forms a precipitate with calcium sulphate solution on standing, and a precipitate with calcium chloride solution quite readily ; also, the calcium precipitate, dissolved by hydrochloric acid, is precipitated again by ammonia (distinc- tions from dextro tartaric acid). RHOEADINE. See OPIUM ALKALOIDS, p. 360. RICINOLEIC ACID. See FATS AND OILS, pp. 246, 248, 289. RESIN, COMMON, SEPARATION OF. See FATS AND OILS, p. 2T8. ROSIN OILS. See p. 280. SAFFLOWER RED. See COLORING MATERIALS, p. 191. SAFFRANINS. See p. 183. SALICYLIC ACID. Salicylsaure. Acide Salicylique. C 7 H 6 O 3 = 138 (monobasic and with alkalies feebly dibasic). In structure, C 6 F1 4 .CO 2 H.OH, in which CO 2 H : OH = 1 : 2, or- tho-hydroxybenzoic acid. There is but one salicylic acid, but it is one of three isomeric hydroxybenzoic acids (or phenol- car- boxylic acids), namely -the ortho, meta, and para compounds, with the respective positions of 1:2, 1:3, and 1 : 4, for CO 2 H : OH. Sources. Free salicylic acid occurs very sparingly in nature, having been found in the flowers of Spiraea ulmaria, in Yiola tricolor and other species of viola, and in the Gloriosa superba of the East Indies. The ethereal salt, salicylate of methyl, C 6 H 4 .CO 2 (CH 3 ).OH, is known as "wintergreen oil." Methyl salicylate forms the larger part (over 99 per cent., PETTIGREW, 1884; 90 per cent., CAHOURS, 1843) of the oil of gaultheria, U. S. Ph. ; according to Pettigrew the whole of the " oil of birch," from Betula lenta bark, commonly sold as " wintergreen oil " ; and nearly or quite the whole of the oil of Andromeda Leschenaultii, of abundant growth in Hindostan, and the volatile oil of Mono- tropa Hypopitys of northern Europe. It is also found in the oils of several species of Gaultheria and in oil of Polygala pauci- flora ; sometimes in oil of cloves, and in oil from buchu leaves. 434 SALICYLIC ACID. Salicylic acid may be prepared from methyl salicylate by boiling with potassium hydrate solution until the oil is dissolved, and as long as methyl alcohol is given off, and then acidulating with hydrochloric acid, when the salicylic acid precipitates. Since 1874 salicylic acid has been extensively manufactured from carbolic acid by Kolbe's method. 1 Dry sodium phenol, C 6 IT 5 ONa, is treated with dry CO 2 , at a temperature increased to!80C. and finally to about 225 C., whereby disodium sali- cylate, C 6 H 4 . CO ? Na . ONa, is formed in the retort, and half the phenol taken is distilled over. Small portions of para-hy- droxybenzoic acid and traces of a phenol-dicarboxylic acid are formed (Osx, 1879). If potash be used instead of soda the pro- duct is the para-hydroxybenzoic acid. But impurities of greater proportion in salicylic acid made from carbolic acid probably result from the impurities in the latter, namely, from the cresols homologous with phenol (the " cresylic acid " ) present in carbo- lic acid (see Phenol). Each of the three cresols, C 7 H 8 O, treated with sodium and carbon dioxide, forms a cresotic acid, C 8 H 8 O 3 . The cresotic acids so formed are sometimes termed the homo- salicylic acids, and are direct homologues of salicylic acid, hav- ing the rational formula, C 6 H 3 (CH 3 ).CO 2 H.OH, with the posi- tions CO 2 H : OH : CH 3 = respectively 1 : 2 : 3, and 1 : 2 : 4, and 1 : 2~: 5. a 1 Concerning recent manufacture of salicylic acid through formation of diphenyl carbonate, at the works of Aktien (late Schering) in Berlin, see Jahr. chem. 'Tech., 1884, 504; HENTSCHELL, Jour, prakt. Chem., 27, 39, and Jour. Soc. Chem. Ind., 3, 115, 646. 2 These three cresotic acids are but three isomers among ten known isome- ric hydroxytoluic acids (or cresol-carboxylic acids) obtained from various sources. BeilxteiiiS Organisch. Chemie. 1883, p. 1457. In part in " Watts's Diet.," viii. 2023. Concerning certain of these acids and xylene products, Am. Chem. Jour., 3, 424; 4, 186. Concerning three hydroxyxylenic acids, GUNTER, 1884: Brr. d. chem. Ge*., 17, 1608; Jour. Chem. Soc.\ 1884, Abs.. 1347. It will be observed that the occurrence of homologues in salicylic acid from coal- tar corresponds to the existence of homologues in carbolic acid and in the benzoles, as follows: 1. Benzene C 6 H 8 . Toluene C 7 H 8 . Xylenes C 8 Hi . 2. Phenol C 6 H 6 0. Cresols (see p. 394) C 7 H 8 0. Xylenols . C 8 H 10 0. Benzoic acid C 7 H 6 Oa . Toluic acids. C 8 H 8 O a . Xylenic acids C 9 H 10 O a . 4. Salicylic and two other hydroxybenzoic acids . C 7 H 6 3 . Cresotic and other hy- droxytoluic acids C 8 H 8 3 . Hydroxyxylenic acids. . . C 9 Hi 3 . SALICYLIC ACID. 435 The question of the occurrence of the homologues and iso- mers of true salicylic acid, in the article made from carbolic acid, is further treated under Impurities (g\ At all events, the crude sodium salicylate of Kolbe's process is acidulated with hy- drochloric acid, and the resulting crude salicylic acid is purified in various ways, by crystallizations from dilute alcohol or hot water, by dialysis of the sodium salt, and by filtration through purified animal charcoal. Dr. Squibb (1877) employed sublima- tion of the acid by heat from steam. For some years the " natu- ral salicylic acid " has been manufactured from " wintergreen oil " in this country, for medicinal purposes, with claims for supe- rior purity. The essential oil 'of the flowers of Spiraea ulmaria, Salicylol, is the aldehyd of salicylic acid. The glucoside Sali- cin, the active principle of Salix, readily liberates the correspond- ing alcohol, saligenin. From all these substances, from indigo, and from coumaric acid, salicylic acid can be obtained by heat- ing with potassium hydrate under suitable conditions, and by other chemical treatment. SALICYLIC ACID is identified by its crystalline form and physi- cal deportment (), its reaction with ferric salt and with nitric acid, and the odor of its methyl ester (d). From Benzoic acid it is distinguished by the odor of the respective products with so- dium amalgam in presence of water, and with lime by heating when dry (d) ; from Cinnamic acid by the permanganate oxida- tion of the latter to benzoic aldehyde. It can be separated and its valuation secured (e) by distillation from its salts (1), or of the free acid (3) ; by solvents not miscible with water (2) ; by dialy- sis (4) ; and in special methods from Wine and Beer (p. 440), Canned Fruits, Milk (p. 440), and the Urine (p. 441). Quantita- tively it is estimated (/*) by the colorometric method, or weighed as free acid. It is examined respecting impurities and require- ments of quality (g) witli regard to its modes of manufacture (p. 434) and its chemical isomers (p. 443), by application of re- cognized special tests (p. 444). For Salicyluric Acid see p. 445; Salicylate of Sodium, p. 445 ; other salicylates, p. 437. a. Salicylic acid is furnished, according to its grade, in fine, needle-shaped crystals, or in a loose or granular powder, obscure- ly crystalline or nearly amorphous. White when pure, it is fre- quently blemished with a yellowish, or pinkish, or brownish tinge. The dialyzed acid is said to keep perfectly white. The " recrystallized " acid is a good pharmacopoeial brand ; the "pre- cipitated " acid is of a lower grade ; the " sublimed '' acid is said 436 SALICYLIC ACID. to acquire color and carbolic odor. The crystals are monoclinic (MARIGNAC, 1855). From moderately warm aqueous solution it is obtained in four-sided prisms, from hot aqueous solution in needles, from alcoholic solution by spontaneous evaporation in large four-sided columns, from a drop of ether-solution evapo- rated on a glass slide in star form or feathery groups of radiate needles requiring to be magnified 50 to 100 diameters (HAGER). Sp. gr. 1.483 at medium temp., taking water at 4 C. as 1 (ScHROEDEK, 1879). Permanent in the air. Melts at 156 C. (312 F.) (HtiBNER, 1872 ; KOHLER, 1879). Sublimes unaltered by heat from steam at 60 to 80 Ibs. pressure, not above 145 C. (293 F.), the product having no carbolic odor (SQUIBB, 1883). Suddenly heated, at 220-230 C. (428-446 F.), it is resolved into phenol and carbon dioxide, leaving no residue, and when sublimed without care the sublimate is contaminated with phe- nol and gives a carbolic odor. In boiling its aqueous solution it vaporizes unaltered with the steam. Heated with concentrated hydrochloric or dilute sulphuric acid, under pressure, at 140- 150 C., it is dissociated into phenol and carbon dioxide. Alkali salicylates oxidize readily. b. Pure salicylic acid is odorless and has a sweetish, acidu- lous, acrid taste. The acid of commerce sometimes has the odor of phenol or of cinnamic acid. Salicylic acid is not caustic, but is somewhat irritant to mucous surfaces, the more so by inhala- tion in dust. It is medicinal in ordinary doses of 10 to 60 grains. If more than 150 grains be given within twenty-four hours some disturbance usually follows. The alkali salicylates have the effect of the acid, as does also methyl salicylate (Gaultheria oil) (H C. WOOD and H., 1886). In hypodermic injections about 0.2 per cent., or the strength of a cold saturated aqueous solution of the acid, is employed. For external application 1 to 10 per cent, solutions are used. Salicylic acid is removed from the system with moderate rapidity, most largely by the urine, in part by the bile, and in traces by the saliva. Gaultheria oil becomes free salicylic acid in the living body (WooD, 1886 : Ther. Ga- zette, 10, 73). In the urine salicylic acid is excreted as salicyluric acid, with unchanged salicylic acid. Other reported excretory products are phenol, salicin, and indican. Salicylic acid, in proportion of about 0.1 per cent. (J- grain to the fluid- ounce), preserves ordinary vegetable infusions. For fruit juices, cider, etc., 0.05 to 0.3 per cent, is requisite, but 0.01 to 0.02 per cent, exerts a degree of conserving power. To preserve hypodermic and alkaloidal solutions Dr. Squibb uses the full or half strength SALICYLIC ACID. 437 of a cold water saturated solution (0.2 or 0.3#) . 1 As an antizymotic, or antiseptic, the salicylates have much less power than the free acid, and a sufficient quantity of bisulphate of potassium may be added to complex liquids, with salicylic acid, to prevent its com- bination with the bases of acetates, etc. The use of salicylic acid in foods has been forbidden in some countries. c. Salicylic acid is sparingly soluble in water: at 15 C. (59 F.) it requires 444 parts; at 20 C. (68 F.). 3TO parts; at 30 C. (86 F.), 256 parts; at 100 C. (212 F.), 13 parts (BouR- GOIN, 1879). Heated with water under pressure, the acid dis- solves water and liquefies (ALEXEJEFF, 1883). In alcohol of 90$ it dissolves in 2.4 parts at 15 C. (59 F.) ; in absolute alcohol, in 2 parts at 15 C. It dissolves, at 15 C. (59 F. ), in 2 parts of ether, in 3.5 parts of amyl alcohol, freely in methyl alcohol, in 80 parts of benzene, in 80 parts of chloroform, in 60 parts of glycerin, and in about 60 parts of ordinary fixed oils. It dissolves in carbon disulphide and in volatile oils. 3 Salicylic acid has an acid reaction ; it causes effervescence from carbonates ; it forms moderately stable monobasic or normal salts (as C 6 H 4 .CO 2 Na. OH), those of the alkali metals being neutral to litmus (when pure), and instable dibasic salts (as C 6 Il4 . CO 2 Na . OKa) of alkaline reaction. For conserving certain alkaloids the salicylate is a very favorable salt. Of the normal salts, those of alkalies, calcium, barium, magnesium, zinc, and copper dissolve in water, the lead salt in hot water, but the silver salt does not readily dissolve. The basic salts of non- alkali metals are not soluble in water. Salicylate of quinine, C 20 H 24 X 2 O 2 .C 7 H 6 O 3 4(H 2 O), is neutral and soluble in 900 parts of cold water or 20 parts of alcohol ; salicylate of atropine is neutral and very soluble in water. With the alkali salts of the weaker acids salicylic acid dissolves freely in water, making comparatively concentrated solutions, which, however, are really solutions of salicylates. Borax, acetate of potassium, and acetate of ammonium are used, also alkali phosphates and citrates, with water, as solvents. With borax a crystallizable union is obtained, IS T aC 7 H 5 O 3 + C 7 H 5 (BO)O 3 , of acid reaction. With half its 'ROBINET and PELLET, 1882: Compt. rend., 94, 1322; Jour. Chem. Soc., 42.1010. BERSCH, 1882: " Biedermann's Centralblatt," p. 340; Jour. Chem. Soc., 42, 1010. HEINZELMANN, 1884: "Biedermann's Centraiblatt," p. 503; Jour. Chem. Soc., 46, 764. " Hager's Phar. Praxis," Erganzungsband, 43. SQUIBB'S Ephemeris, 1882-85: i, 414; 2, 833. 2 LANGBECK (1884) reports widely varying solubilities of salicylic acid in different essential oils, and uses this difference to distinguish volatile oils from each other: Reptrt. anal. Chem., 12, 177; Jour. Soc. Chem. Ind., 3, 547. 438 SALICYLIC ACID. weight of borax, and 2J times its weight of glycerin, a 25 per cent, solution of salicylic acid may be obtained. The combina- tion with boric acid, borosalicylic acid, C 7 H 5 (BO)O 3 . C ? H 6 O 3 , is soluble in 200 parts of cold water (HAGER). Glycerin sali- cylate can be formed (GoiriG, 1877). Solutions of salicylic acid and its salts are not easily preserved, and acquire color by standing. d The stronger acids precipitate salicylic acid from solu- tions of its salts in less than 200 to 400 parts of water. Silver nitrate solution, with solutions of saiicylates, not with solution of salicylic acid, forms a white precipitate of silver salicylate, C 7 H 5 AgO 3 , dissolved by boiling water, also by nitric acid and alcohol. Ferric chloride solution, with solutions of salicylic acid or its salts, gives (according to dilution) a violet-blue to violet-red color of great intensity. The alcoholic solution of free acid is most favorable. A little less delicate than the sul- phocyanide reaction (E. F. SMITH, 1880), it reveals salicylic acid diluted to 100000 parts (ALMEN, 1878). The reaction is pre- vented by alkalies, and hindered by alkali acetates, phosphates, borates, potassium iodide, and by oxalic, tartaric, citric, phos- phoric, and arsenic acids, not by dilute acetic, boracic, sulphuric, or nitric acid, nor by glycerin, alcohol, ether, common salt, or nitre (HAGER, 1880). The ferric violet reaction is given by sali- cyluric acid and oil of spiraea, not by para or by meta oxy ben- zoic acid; and red to blue ferric colors are given by brorno and nitro salicylic acids and salicyl-sulphonic acid. (See Car- bolic acid, ferric reaction.) Bromine water gives a crystalline precipitate, 7 H 4 Br 2 O 3 , very slightly soluble in water, freely soluble in alcohol. Solution in 40000 parts of water gives crystals seen under the microscope (ALMEN, 1878). Nitric acid, if concentrated, in the cold, and if dilute, by warming, forms nitro-salicylic acids, then by more intense action forms nitro- phenic (picric) acids, the latter recognized by its intense red- brown color. The reaction is most promptly obtained by Mil- Ion's reagent, fuming acid mercuric nitrate, and gives color in dilution with 1000000 parts of water (ALMEN, 1878). Copper sulphate, with neutral solution of salicylate, gives a green color. Glucose with from two to three times its weight of salicylic acid, the mixture warmed with excess of sulphuric acid (concen- trated), gives a fine blood-red color. Nearly the same color is fiven by benzoic acid in this test ; a brown to blood-red color by ippuric acid (PHIPSON, 1873). Sodium amalgam, warmed in a slightly acidulated solution, gradually reduces salicylic acid to SALICYLIC ACID. 439 its aldehyde, oil of spiraea, C 6 H 4 .COH.OH, recognized by its odor (compare with Benzoic acid). A mixture of equal volumes of sulphuric acid and methyl alcohol, distilled from a small portion of residue containing salicylic acid or salicylate, yields a distillate odorous of wintergreen oil, methyl salicylate, CH 3 .C 7 H 5 O 3 . Ethyl salicylate, formed in a corresponding way, has a similar odor. Heated with lime, salicylic acid gives the odor of phenol, obtained also by heating salicylates alone (see a). Salicylic acid reduces permanganate of potassium solution, but does not reduce potassium 'cupric tartrate. Sulphuric acid, not diluted, in contact with salicylic acid at a gentle heat, pro- duces salicyl-sulphonic oeuf (1&EM8KN, 1875), C 6 H 3 (SO 3 H) . OH . CO 2 H = C 7 H 6 SO 6 , a quite stable acid, forming both monobasic and dibasic metallic salts, all soluble in water, mostly insoluble in alcohol. e . Separation. (1) Evaporation on the common water-bath carries away free salicylic acid, and is inapplicable to its aqueous solutions. To prevent waste by evaporation, either bicarbonate of sodium or ammonia- water is added to obtain a permanent neutral or very slightly alkaline reaction during the concentra- tion. Long evaporation now endangers loss by decomposition. If a dry residue be desired, the choice of ammonia for saturation of the acid has this advantage : if the evaporation be concluded and the residue dried at a gentle heat, the excess of ammonia is expelled. After acidulating the residue the salicylic acid may be separated by suitable solvents, or dissolved to estimate by the colorimetric method. Alcohol, ether, chloroform, benzene, etc., may be evaporated or distilled from salicylic acid without its waste. (2) Shaking with chloroform, ether, amyl alcohol, or benzene is very generally employed to remove salicylic acid from watery solutions. If the acid be not wholly free from combination with all bases, it must be liberated by addition of sufficient acid, preferably dilute sulphuric or phosphoric. The solvent must be applied, in successive portions, as long as a portion, evaporated, responds to the ferric chloride test for salicylic acid. Ether has been much used ; chloroform is preferred by MALENFENT (1885) ; chloroform or benzene by DRAGENDORFF (1878). When the sol- vent emulsifies and fails to separate from the watery layer, as may occur, the concentrated aqueous solution (not acidulous) may be acidified and mixed with about twice its weight of ground gypsum, enough to take up the liquid, the stiffened mass dried at a low heat, pulverized, the powder shaken with ether or other 440 SALICYLIC ACID. solvent, the mixture filtered and the residue washed (CAZENEUVE, 1879). After evaporation of the solvent, the residue, if free from other solids, may be weighed as salicylic acid, or, whether pure or not, dissolved in water and estimated by the colorimetric method. (3) Distillation with water, from acidulous watery solutions, by boiling, has been much used to obtain the salicylic acid in the distillate, for colorimetric estimation. 1 DENNY found this method ineffective in examination of foods. 9 (4:) Dialysis of salicylic acid has been resorted to for its esti- mation in wine and beer, milk, and animal fluids (MUTER, 1876; AUBRY, 1880). Muter recovered from milk 90$ by dialysis. Animal membrane is the best dialytic septum for this pur- pose. In separation from wine, cider, and l)eer the alcohol may first be removed by evaporation to one-third volume, at 70-80 C. (REMONT, 1881). After extraction with chloroform or ben- zene, in repeated portions, the residue from evaporation of the solvent may be dissolved in another solvent (as with benzene if chloroform were first used), this solution evaporated, and the residue taken up in hot water to a definite volume in ratio to that of the wine, for colorimetric estimation. Dialysis is some- times used in preliminary treatment. A simple test may be readily made by shaking 50 c.c. of wine with 5 c.c. of amyl al- cohol ; after standing the layer of solvent is taken oft' and diluted with an equal volume of alcohol, then tested with a few drops of ferric chloride solution for the violet color (JWEIGERT, 1880). In examination of canned fruits Mr. Denny used the fol- lowing method : 3 The expressed liquids, with sparing washings, were boiled and filtered through glass wool. To 50 c.c. of the filtrate, acidulated, 5 to 8 c.c of amyl alcohol were added, the whole shaken, the amyl alcohol drawn off, diluted with an equal volume of ethyl alcohol, and this liquid tested with ferric chlo- ride. In examination of milk for salicylic acid REMONT (1883) takes 20 c.c. of the milk, adds two or three drops of sulphuric acid, and agitates to break up the coagulum, when the mass is shaken with 20 c.c. of ether and set aside in a stoppered tube. 10 c.c. of the ether layer are taken in a test-tube marked at 10 c.c., the ether evaporated, and the residue of butter is boiled with alcohol of 40$ strength, and the liquid, when cold, made 1 Archiv der Pharm. [31 21, 296; Jour. Chem. Soc., 1884, Abs., 372. a Contributions Chem. Lab. Univ. Mich., 1883, 2 81. 3 Contributions Chemical Laboratory, Univ. Mich., 1883, p. 80. SALICYLIC ACID. 441 up to 10 c.c. and assumed to contain nearly the salicylic acid in 10 c.c. of the milk. 5 c.c. of the solution are then filtered into a graduated tube for colorimetric estimation. But the colorime- tric standard recommended is one obtained by adding a known quantity of salicylic acid to pure milk 0.1 to 0.2 gram to the 20 c.c. in a parallel operation. PELLET (1882) takes 200 c.c. of milk, with 200 c.c. of water, and at 60 C. adds 1 c.c. acetic acid and an excess of mercuric oxide (|- c.c. each of acetic acid and mercuric nitrate solution Girard, 1883). When cold, the whey is filtered out, agitated twice with 100 c.c. of ether, the ether solution washed, passed through a dry filter, and evapo- rated. The residue is taken up in dilute alcohol for colorimetric estimation. In examination of ~butter, 10 to 50 grams may be boiled with alcohol diluted to 40 or 50 per cent, strength, and the fil- tered solution, concentrated to a definite volume, titrated in the colorimetric way. For the detection of salicylic acid in the urine, unless highly colored, it may be tested directly by adding the ferric chloride, in a deep test-tube observed from above. Salicyluric Acid (see p. 445) gives the same ferric reaction as salicylic acid. The precipitate of ferric phosphate may be filtered out and more of the reagent added to the filtrate for better result. And if the urine be high-colored, it is to be made alkaline with alkali car- bonate, treated with an excess of lead nitrate solution, shaken strongly, filtered, and the filtrate tested with the ferric chloride. But in most cases the direct test gives the best result (SIEBOLD and BRADBURY, 1881). In 1878 Robinet recommended prepar- ing the urine by precipitation with sufficient lead acetate solu- tion, adding ferric chloride to the filtrate, and then (PAGLIANI, 1879) adding dilute sulphuric acid, drop by drop, till the red color of ferric acetate just disappears, when the violet test-color will be seen, with least interference from the sulphuric and ace- tic acids. If the filtrate be too dark, basic acetate of lead solu- tion may be used instead of the normal acetate, otherwise re- sults are closer after use of normal acetate. 1 With 0.002 per cent, of salicylic acid in urine a distinct reaction can just be reached ; with 0.005 per cent, a very distinct color is obtained (Borntrager). f. Quantitative. Salicylic acid in crystals may be weighed 1 BORNTRAGER, 1881: Zeit. anal. Chem.. 20, 87; Jour. Chem. Soc., 40, 472. (In the Chem. Soc. Abstract, Bleiessigis given as "impure acetate " of lead in distinction from Bleizucker, "pure lead acetate.") 442 SALICYLIC ACID. as C 7 H 6 O 3 . Neither the free acid nor any of its salts is insolu- ble enough to be precipitated for estimation. The sublimate by carefully limited heat (see a) could be weighed, instead of the crystals. But a colorimetric method by ferric chloride, in com- parison with depth of color from known solution of salicylic acid, was given by DR. MUTER, in 1877, as follows : 1 The solutions required are . (1) of pure salicylic acid (by dia- lysis and recrystallization) 1 gram in water to make 1000 c.c. ; (2) of ferric chloride such a dilute solution that 1 c.c., treated with 50 c.c. of the standard solution of salicylic acid, just cease to give increase of intensity of color before the last drop or two of last-named solution is added. If commercial salicylic acid is to be valued, dissolve 1 gram in water to make 1 liter, and take 50 c.c. in a Nessler tube (or a seven or eight inch test-tube). Of any solution recovered by separation, take 50 c.c., or a quantity to dilute to 50 c.c., in the tube mentioned. Add 1 c.c. of the ferric chloride solution to the 50 c.c. of the solution to be esti- mated. In one or more tubes of same width take now, in each, 1 c.c. of ferric chloride solution and as many c.c. of the standard solution of salicylic acid as deemed necessary, and dilute to 51 c.c. After five minutes, or if acetic acid be present after ten minutes, compare the color in the tubes. Repeat the trial with the standard solution until a depth of tint is obtained the same as that from the solution under estimation. Then, in the trial giving equality of tint, the c.c. of the standard salicylic acid so- lution X 0.001 = grams of salicylic acid in the portion taken for estimation. And if the solution under estimation be that of 1 of commercial acid made up to 1000, then c.c. of standard acid X 2 = per cent, desired. Salicylic acid, with ferric chloride, has been proposed (WEISKE, 1876) as an indicator in acidimetry. It is much less definite than litmus (MOHR, " Titrirmethode "). The violet color deepens in intensity as the neutral point is approached, but as soon as this point is passed the color pales to reddish-yellow. Apparently the titration of salicylic acid, with volumetric solu- tions of soda, using ferric chloride as an indicator, should give fairly good results, more trustworthy if the volumetric alkali be standardized by a known solution of pure salicylic acid an r ^ solution = 1.38 gram salicylic acid in a liter. Each c.c. of al- kali normal solution = 0.1 38 gram of salicylic acid. g. Impurities, and tests of purity. Color may be due to coal-tar compounds, or to iron as ferric salicylate. Carbolic 1 Analyst, I, 193. SALICYLIC ACID. 443 add is for medicinal purposes a quite dangerous impurity, but so obvious that it is not likely to be neglected by the manu- facturer or tolerated by the purchaser, and it is more liable to arise in minute quantities from decomposition of an article not pure enough to be stable. The cresotic acids (see Sources, p. 34) are probably the most abundant, and it may be feared the most serious, impurities in the salicylic acid made from car- bolic acid. In 1878 Mr. Williams, 1 by investigations not com- pleted, reported from 15 to 25 per cent, of " secondary " or al- lied acids, much more soluble than true salicylic acid but less soluble than para- hydroxybenzoic acid, in " the best " artificial salicylic acid of the market. In 1883 Dr. Squibb 2 said that the better grades of well- crystallized acid of the market con- tained 4 to 5 per cent. u of something which is not salicylic acid " but is inferred to be homologous acid, and " not present in so large a proportion as when Mr. Williams wrote." The homosalicylic or cresotic acids are described as " deceptively like salicylic acid, " and ' ' behaving with solvents and reagents almost exactly like salicylic acid." * On the contrary, the two isomeric hydroxybenzoic acids are so much more soluble in water than true salicylic acid that they must be well removed from the recrystallized acid. 4 Williams and others remove sali- l Phar. -Jour. Trans. [3] 8, 785; Pro. Am. Pharm., 26, 536. 2 Ephemeris, I, 412. 3 " Watts's Diet.," 3d sup., pp. 584, 2024. 4 The following table gives properties, so far as found, for (1) the two isomers of salicylic acid ; (2) those of the next homologues of salicylic acid which are found to be formed from cresols by Kolbe's method, and have been termed cresotic acids; and (3) three reported homologues removed two places from salicylic acid, or xylenol products. (See the foot-note under Sources.) Melting, c. Vaporizing. Solubility in water (parts). In alcohol. In chloro- form. ferric reac- tion. 1. By droxy 'benzole acids: Salicylic acid (ortho) . Metahydroxybenzoic. Parahydroxybenzc'c . 2. Hy droxy toluic acids : C0 2 H : OH : CH 3 = (Cresotic or " hoiuo- salicyhc acids ") 1 :2: 3... 156 200 210 160 With steam. Not with steam. With steam 444 108 at 18 C. 126 at 15 C. 2.4 Freely. 80 Little. Freely. Violet. No color. Yellow pre. Violet. 1 :2 :4 173 * 1:2:5 151 *i Easily Easily ii 3. IJydroxyxylenic acids: E. Gunt'er, 1884. (1). (2) (3). 170.5 144 153 Not with steam. With steam. No color. Blue. No color 444 SALICYLIC ACID. cylic acid from its homologous acids, in a purification of the arti- ficial salicylic acid of the market, by the comparative insolubi- lity of the calcium salicylate, as follows : The acid is treated in boiling water solution with carbonate of calcium in excess, the solution of salicylate crystallized by cooling of the filtrate, the salt recrystallized repeatedly, and finally acidified with hydro- chloric acid, to obtain true salicylic acid. The mother-liquors from the calcium salicylate, acidified with hydrochloric acid, gave the homosalicylic acids, not fully examined. Hydrochlo- ric acid and chlorides are obviously incidental impurities. The pharmacopoeia of France (1884) places glycerin among the im- purities, and as falsifications names sugar, starch, silica, calcium sulphate, potassium disulphate, etc. Carbolic acid is likely to be revealed by the odor on opening a bottle. Closer examination may be made by warming about a gram (15 grains) in a (dry) test-tube immersed for a quarter of an hour in water a little below boiling temperature, when no odor of carbolic acid should be obtained. Carbolic acid may be separated and concentrated by making a solution w T ith excess 'of sodium carbonate and water, shaking with ether, and evaporating the ethereal solution (Ph. Germ., 1882). A test by the chlo- rate of potassium and hydrochloric acid reaction for phenol, adopted in the U. S. Ph., 1880, has been said to give a pinkish coloration with the best obtainable medicinal grades of acid (SQUIBB, 1883). ALMEN (1877) employs chlorinated soda solu- tion and ammonia, avoiding an excess of the chlorinated solution, and adding, last, ammonia to an alkaline reaction a blue color, red in acidulous and blue in alkaline reaction, reveals l-5000th of phenol at once, l-50000th after twenty-four hours. For organic matters, indeterminate, treatment with sulphuric acid, without heat, is official in the U. S. and German pharma- copoeias. 1 One part of the salicylic acid (0.2 to 0.3 gram) (3 to 5 grains), with 15 parts concentrated sulphuric acid (U. S. Ph.), 6 parts (Ph. Germ.), 6 to 10 parts (Ilager), the mixture stand- ing 15 minutes (IT. S. Ph.), without specification of time (Ph. Germ.), should give no color (U. S. Ph.), should be nearly with- out color (Ph. Gerrn.), with the 6 to 10 parts of sulphuric acid should give a colorless or pale yellow solution, brown colors indicating insufficient purity (Hager, in " Commentar ''). For or- ganic matters and iron an evaporation of the alcoholic solution has been prescribed by Kolbe (1876, and von Heyden, 1879), and 'This test was advised by HAGER in 1876: Phar. Centralh , 17, 434; and with additional confidence in 1883: "Commentar." 194. SALIC YLURIC ACID. 445 is official in the pharmacopoeias, U. S., Br., Germ. "A satu- rated solution in absolute alcohol, when allowed to evaporate spontaneously in an atmosphere free from dust, should leave a perfectly white crystalline residue, without a trace of color at the points of the crystals (absence of [certain] organic impuri- ties ; also of iron) " (U. S. Ph.) Prof. Kolbe directs to dissolve 3 to 5 grams (50 to 75 grains) of the acid in the smallest possible quantity of absolute alcohol, and pour the clear solution on a watch-glass over a white surface. Mechanical impurities will be perceptible at once. The solution is left to evaporate in an atmosphere free from dust, especially from iron, and crystals in efflorescence are obtained. li points of crystal- borders are brown, resinous, or phenol-like, impurity is indicated ; if light yellow, organic dye ; if violet or pink, iron. Hager insists that this test is much less trustworthy than that with concentrated sulphuric acid. For hydrochloric acid and chlorides, "a solu- tion in 10 parts of alcohol, mixed with a few drops of nitric acid, should not become turbid on addition of a few drops of test so- lution of nitrate of silver." For non-volatile matters test is readily made by vaporization, which should leave no residue. Hager directs to heat 0.15 to 0.2 gram (2 to 3 grains) in a test- tube } inch wide, by moving it through the flame, when at last no stain should be left. In the vaporization odor of phenol is usually developed. SALICYLURIC ACID C 9 H ? ]TO 4 ==C 6 H 4 . CO. NH. CH 2 . CO 2 H. OH. Occurs in the urine after administration of salicylic acid (J, p. 436). Crystallizes in fine needles. Melts at 160 C., and de- composes at 170 C. , with vaporization of salicylic acid. Sparingly soluble in cold water, easily soluble in alcohol, soluble in ether, less soluble in a mixture of ether and benzene than salicylic acid is (BECK, 1876), and thereby separated. Forms stable salts. With ferric chloride gives deep violet color. SALICYLATE OF SODIUM. C 6 H 4 .CO 2 ]S r a.ONa4(H 2 O)= 338. For description and tests of purity see U. S. Ph., 1880. Its re- action is not acidulous if it be wholly free from uncombined salicylic acid. Even when kept in tight bottles, as required, the salt is liable to acquire color by storing. According to Hager, this is due to formation of phenol. Both the ammonia and the carbon dioxide of the air induce decomposition to the extent of giving color. In operating with the salt, traces of iron in filter- paper and in waters must be avoided. The aqueous solution is instable, and darkens on standing. Mr. Martin (1883) states 446 STRYCHNOS ALKALOIDS. that the addition of thiosulphate (hyposulphite) of sodium, 1 part to 128 parts of the salicylate, prevents the coloration of the latter in aqueous solution. Carbolic acid as an impurity may be recognized by its odor, the better on warming, not above about 90 C. It may be separated for identification by shaking the aqueous solution, exactly neutralized, with ether, and evaporat- ing the latter at ordinary temperature. SALICYLURIC ACID. See p. 445. SANDAL RED. See COLORING MATTERS, pp. 189, 191. STEARIC ACID. See FATS AND OILS, p. 240. STRYCHNOS ALKALOIDS.-The alkaloids found in the Strychnos nux-vomica, S. Ignatii, S. colubrina, and Upas Tieute, of the natural order Loganiaceae. Strychnine, C 21 H 22 N 2 O 2 . PELLETIER and CAVENTOU, 1818, p. 447. Brucine, C 23 H 26 N 2 O 4 . PELLETIER and CAVENTOU, 1819, p. 463. Igasurine. DESNOIX, 1853 ; existence called in question by SCHUT- ZENBERGER, 1858 i Ann. Chim. Phys. [3] 54, 65. SHEN- STONE, 1881 : Jour. Chem. Soc , 39, 453. Constitution of Strychnine and Brucine. Brucine has the elements of dimethoxy-strychnine, C 21 I1 20 (OCH 3 ) 2 N 2 2 . SHEN- STONE/ and later HANSSEN, 3 have shown it well-nigh certain that brucine actually is dimethoxy-strychnine, and are working upon the problem of artificial conversion of the one into the other. HANSSEN finds the body C 16 H 18 N 2 O 2 to be common to both strychnine and brucine, and to be changed by oxidation with sulphuric and chromic acids into C 16 H 18 N 2 O 4 . The announce- ment of SoNNENSCHEiN, 8 in 1ST5, that brucine is converted into strychnine by treatment with nitric acid, carbon dioxide being evolved, has not been confirmed, and this conversion is denied by HANRIOT (1884).* The physiological relations of brucine and strychnine have been investigated by BRUNTON,* with comparison, also, with methyl-strychnine, a product under trial as to its effects. 1 1883-85: Jour. Chem. Soc., 43, 101; 47, 139; Ber. d. chem. Ges , 17, 2849. 3 1884-86: Ber. d. chem. Ges., 17, 2849; 18, 777, 1917; 19, 520; Jour. Chem. Soc., 48, 276, 819, 1146; 50, 564. 3 F. L. SONNENSCHEIN: Ber. d. chem. Ges., 8, 212; Jour. Chem. Soc., 28, 771. 4 Compt. rend., 97, 267; Jour. Chem. Soc., 46, 88. 6 1885: Jour. Chem. Soc., 47, 143. STRYCHNINE. 447 Yield of Strychnos Alkaloids. Total alkaloids : 1.65 to 2.88 per cent. (DRAGENDORFF, 1874 '). More than is generally supposed, the richest specimens reaching nearly 4 per cent. (DUNSTAN and SHORT, 1883-85, by their own method 2 ). Dr. A. B. LYONS, in 1885, 3 stated the results of twelve specimens, from 2.68 to 4.89 per cent., giving a mean of 3.16 per cent. Of strychnine alone, 0.96 to 1.39 per cent, in the results of a few lots (DRAGENDORFF, 1874). As a generally accredited statement, from analyses older than the recent methods, strychnine is found in Ignatius bean as high as 1.5 per cent. ; in nux-vomica seeds with an average of 0.5 per cent. The statements of Dunstan and Short are given in foot-note below. Methods of analytical separation of strychnine from brucine, in use, are not well assured. Constituents of Nux-vomica, other than the Alkaloids. In combination with the alkaloids, Strychnic or Igasuric Acid, so named, is in fact an iron- greening tannic acid (HoHN, Arch, der Phar., 202, 137). A glucoside, Loganin, 03511.340^, was discovered in nux-vomica by DUNSTAN and SHORT in 1884. 4 In the seeds of Strychnos nux-vomica, and in pharmaceutical prepa- rations made therefrom, it is present in small proportion : in the pulp of the fruit of Strychnos nux-vomica it was found to the extent of 4 or 5 per cent. Loganin, warmed with sulphuric acid, gives a fine red color, which on standing develops into a purple a color-result not unusual to glucosides. By boiling with dilute sulphuric acid a glucose and a body named logane- tin were formed. STRYCHNINE. C 21 H 23 1SI" 2 O 3 = 334. Crystallizes anhydrous. Constitution, p. 446 ; Yield in nux-vomica, given above. Strychnine is identified by the chemical tests of the fading purple, and the crystallization of the dichromate and free al- kaloid, and by the physiological tests of tetanic effect and bit- terness (b and d). Microscopic recognition, a and d. Its limits of quantity are indicated by the limit of response in the fading- purple test (d) and in the physiological tests (b). Solubilities, 1 " Werthbestimmung," p. 64. 2 Phar. Jour. Trans. [3] 12, 1055; 15. 157; Am. Jour. Phar., 55, 467. In the seeds of Ceylon nux-vomica these authors report as follows (Phar. Jour. Trans. [3] 15, 1): No. 1, 1.52 per cent, strychnine, 2.95 per cent, brucine, 4.47 per cent, total. " 2, 1.78 " " 3.16 " " 4.94 " " " 3, 1.71 " " 3.63 " " 5.31 " " " 4, 1.68 " " 2.86 " " 4.54 " " *Proc. Mich. State Phar. Assoc., 2, 173. 4 Pha>: Jour. Trans. [3] 14, 1025; Am. Jour. Phar., 56, 431. 448 STRYCHNOS ALKALOIDS. 0). Limits of recovery from tissues, etc., p. 461. In what organs found in cases of poisoning, 5; how long after death recoverable, e (p. 461). Estimated gravimetri- cally and volumetrically, /. Tests for impurities, g. a. Colorless or transparent octahedra, or needles, or prismat- ic crystals; or a crystalline white or dull white powder. By spontaneous evaporation of a few drops of an alcoholic solution, on a glass slide, a characteristic microscopic field is obtained, and recognized by comparison with a field from known strych- nine under parallel treatment. The crystals may also be ob- tained on diluting a few drops of the alcoholic solution with particles of water applied to the slide by a pointed glass rod. Strychnine melts at about 300 C. In the " subliming cell " at 221 C. (BLYTH, 1878). A microscopic sublimate of needles is obtained at 169 C. (BLYTH, 1878). Sublimes in part un- changed, giving a sublimate recognized under the microscope (HELWIG, 1864). 1 Strychnine Sulphate, (C 2 JI 22 N 2 O 2 ) 2 H 2 SO 4 . 6H 2 O = 874 (COLEMAN, 1883), is efflorescent in dry air; at about 135 C. melts and (near 200 C., RAMMELSBERG, 1881) parts with its water of crystallization (12.36$). Crystallizes in prisms. Crys- tals with 7H 2 O have been reported, and crystals with 5H 2 O are obtained from alcoholic solution. An acid sulphate, C 21 H 22 N 2 O 2 .H 2 SO 4 .2H 2 O, crystallizes in fine needles. The nitrate, normal, crystallizes anhydrous, in groups of silky nee- dles. The hydrochloride, normal, with 1^H 2 O, crystallizes in soft needles or in prisms, and readily effloresces. ~b. The bitterness of strychnine is stated to be perceptible in a solution diluted to 600000 or 700000 parts. The bitter taste is followed by some degree of metallic after-taste. In effect, strychnine is a tetanic poison, to animals as well as man. Locally it has a very slight degree of irritation. Its tetanic ef- fects are due to its action on the gray nerve-tissue of the spinal cord. It is in some part antagonized by chloral hydrate, aconite, hydrocyanic acid, and nicotine, but these do not serve as anti- dotes to its poisonous action. 1 BLYTH: Jour. Chem. Soc., 33, 31-6. HELWIG: Zeitsch. anal. Chem., 3- 46. STRYCHNINE. 449 The smallest known fatal dose for an adult person is half a grain. With adults in ordinary varying degrees of susceptibi- lity, the administration of from J to 2 grains (0.03 to 0.13 gram) is likely to cause death, unless this result be prevented by special conditions or by treatment. Recovery has occurred in cases of poisoning by doses of from 3 to 20 grains, and may occur irre- spective of the quantity taken. The Ph. Germ, places the maxi- mum single medicinal dose of the nitrate at 0.01 gram (^ grain) ; the maximum daily quantity, 0.02 gram. With frogs Marshall Hall found distinctive effects from the immersion of the animal in a solution of strychnine at a limit of 0.0002 grain (0.000013 gram) ; Harley, by injection into the lungs of very small frogs, obtained spasms from as little as 0.00006 grain (0.000004 gram). By carrying the solution, about 2 grains in amount, into the stomach of a frog (Rana Halecina) fresh from the pond, and of from 15 to 50 grains weight, Wormley obtained, from 0.0002 grain (0.000013 gram) of strych- nine, distinctive symptoms in from 10 to 30 minutes ; from 0.002 frain (0.00013 gram), symptoms in 3 or 4 minutes, and death in 5 to 30 minutes ; from 0.02 grain (0.0013 gram) of strychnine, immediate spasms and death in about 8 minutes. With 0.00007 grain (0.000005 gram) of strychnine, symptoms were obtained in some of the very small animals in 50 minutes ; in other ani- mals no symptoms were obtained. No chemical change of strychnine, in its course through the living body, has as yet been demonstrated. In some part, or at some rate, it may suffer oxidation or conversion in the body, as Plugge and others have believed. In a considerable part, at least, it is in many cases excreted, unchanged, in the urine. In other cases of poisoning, analysis of the urine has failed to reveal it. KRATTER (1882) found strychnine in the urine in half an hour after the administration of -^ grain (0.0075 gram) of strych- nine nitrate ; and it continued to be so excreted for 24 hours. When administered several times in succession, it was 3 days after the last ingestion before the alkaloid disappeared from the urine. HAMILTON (New York, 1867) reported the finding of strychnine in the urine on the morning after the patient was poisoned. RAUTENFELD (1884, Dorpat) repeatedly obtained strychnine, in crystalline form, from the urine. McAoAM found it in the urine of a dog nine minutes after the administration of half a grain, and before symptoms of poisoning appeared. Usually, however, it is not to be found in the urine of animals quickly killed by it. In two cases of dogs, with death after, respectively, 40 and 100 minutes, WORMLEY failed to find the 450 STRYCHNOS ALKALOIDS. poison in the urine. In the liver it is retained to an extent greater than has been found in any other organ (DRAGENDORFF and MASING, HUSEMANN, ANDERSON). In other organs and in the tissues of poisoned animals its recovery by analysis is very uncertain. "When death of the animal very shortly follows the administration, it is in many cases to be found in the blood. DRAGENDORFF concludes from experiments under his direction that strychnine very quickly leaves the blood and becomes re- tained in the liver. 1 G. A. KIRCHMAIER, in experiments made under the observation of the author, found that strychnine was by no means uniformly recovered, even to a qualitative extent, from the blood of animals quickly poisoned with the alkaloid, nor from any of their organs remote from the point of introduc- tion. 3 (As to limits of analysis, in recovery of the alkaloid, see under Separations, e.) 1 "Meine Erfahrung iiber diesen Gegenstand lasst vermuthen, dass das Strychnin sehr schnell dem Blute entzogen und in der Leber zuruckgehalten werde, von wo aus es nur sehr langsam wieder in die allgemeine Saftcircula- tion gelangt, um mit dem Harn aus der Korper entfernt zu werden. Es lasst sich wenigstens bei Hunden und Katzen nicht dafiir einstehen, dass man, selbst wenn der Tod bald nach Darreichung das Giftes erfolgt, im Blute oder den blutreichen Organen (ausschliesslich der Leber) das Gift nachweisen konne. Bei Versuchen, die unter meiner Leitung angestellt wurden, erhielt G. P. Masing bald ein positives, bald ein negatives Resultat, ohne Anhaltspunkte fiir eine Erklarung dieser Verschiedenheiten zu gewinnen " (' Ermittelung von Giften," p. 249). * Experiments by administration to cats, with dissection and analysis beginning not later than 12 hours after death occurred from the action of the poison: G. A. KIRCHMAIER, 1883: Contributions Chem. Lab. Univ. Mich. ,2, p. 91. Strychnine given. How administered. Time before death. Dissection. No. 1. . One-fourth grain. Injection into the back. 2 minutes. In ^ hour. " 2. ... " 3. ... " 4. ... " 5. ... One-sixth grain. One-eighth grain. One thirty -second grain. " " breast. In saphenous vein. By the stomach. 2* S* 11 InX " In 12 hours. " 6. ... One-sixtieth grain. 20 " At once. In cases Nos. 3 and 4 chloroform was administered before the poison was given. Liver. Kidneys. Blood. Heart. Muscle. Muscle near puncture. Stomach. No. 1. " 2. " 3. " 4. 44 5. 44 6. Not found. Found. Not found. n it Not found. Not found. Found. Not found. Found. Not found. Not found. Found. Not found. Found. Not found. STRYCHNINE. 451 Gt Strychnine is soluble in 67000 parts of water at 15 C. ; in 8333 parts at ordinary temperature (WORMLEY) ; in 2500 parts of boiling water ; in 110 parts of alcohol at 15 C. ; in 207 parts of absolute alcohol or 400 parts of common whiskey (WOKMLEY) ; in 12 parts of boiling alcohol ; in about 500 parts diluted alcohol of sp. gr. 0.941 and in 2617 parts of sp. gr. 0.970 (PREScorrand SMITH, 1878) ; in 1400 parts of absolute ether at ordinary tempe- rature (WORMLEY), or in 1250 parts of commercial ether (DRA- GENDORFF) ; in 6 to 8 parts of chloroform ; in 140 parts of benzene (sp. gr. 0.878) ; slightly soluble in petroleum benzin (DRAGENDORFF), requires 1250t) parts (WORMLEY) ; soluble in 122 parts of amyl alcohol; in 300 parts of glycerin (CASS and GARST) ; somewhat soluble in certain essential oils ; sparingly soluble in ammonia-water, not soluble in solutions of fixed alka- lies. Fine octahedral crystals are obtained from the benzene so- lution. Strychnine in alcoholic solution gives a decided alkaline reac- tion to test-papers ; and it forms stable salts, mostly of a neutral reaction. Strychnine sulphate (a, p. 448) is soluble in 42.7 parts of water at 15 C. (COLEMAN, 1883) ; very freely soluble in boil- ing water ; in 60 parts of alcohol at ordinary temperature, or 2 parts boiling alcohol ; insoluble in ether, or chloroform, or ben- zene, or amyl alcohol ; soluble in 26 parts of glycerin. Strych^ nine nitrate is soluble (Ph. Germ.) in 90 parts of cold or 3 parts of boiling water, and in 70 parts of cold or 5 parts of boiling alco- hol. The hydrochloride is soluble in 50 parts of cold water. d. Qualitative tests. The fading purple : If strychnine or one of its ordinary salts, purified from non-alkaloidal matter, in a film of dry residue or a particle of dry mass, on a white porce- lain surface, be moistened with pure concentrated sulphuric acid, in the cold, no coloration occurs. If now a just visible fragment of crystallized potassium dichromate, taken on the end of a nar- row glass rod, be placed for a moment in the moistened film of the test material, and then drawn out through it, a distinct purple to blue color appears, soon changing to reddish- yellow tints, and fading away into the slight colors due to the dichromate itself. The area of moistened film, taken at first, need not be over a fourth of an inch in diameter, and the liquid is drawn in one direction only, toward the side of the dish, as the dichromate is carried through it, in repetition of the trial. The reaction is obtained by the sulphuric acid and an oxidizing agent, and lead peroxide, ceroso-ceric oxide, manganic hydroxide, potassium per- manganate, and potassium ferricyanide have severally been used 452 STRYCHNOS ALKALOIDS. for this purpose. 1 The permanganate, cerium oxide, and ferri- cyanide are usually mixed with the sulphuric acid before the test : one part of permanganate in 2000 parts of the acid, etc. But if this be done the film must be separately tested with sulphuric acid alone. The proportion of oxidizing agent must be minute in testing for minute quantities of the alkaloid. The color given by the oxidizing agent itself, in the sulphuric acid, must be observed. If traces of iion-alkaloidal matters are present, a portion of similar matters is subjected to the same test, and any shades of color developed are to be taken into the account. Bichromate in sulphuric acid has a slight color, from the yellowish-red of the dichromate itself to the chromic sulphate formed by reduction. Permanganate presently becomes green in sulphuric acid. These tints do not resemble the fading pur- ple, and in use of the proper minute quantities of the oxidizing agent they do not obscure the strychnine reaction, or not until the extreme limit of recognition of the latter is reached.' It is to be remembered that the evidence of strychnine depends upon the joining of three results : (1) no coloration by the sulphuric acid, (2) a blue or purple color when the oxidizing agent takes effect, (3) the fading of the blue or purple color. The use of a good hand -magnifier adds efficiency to the test, but all the re- sults should be unmistakable to the eye without special aids. By the manipulation with the dichromate as above given in detail, and applied to a residue from 1 c.c. of solution, a good and strong color can be obtained from 0.0000025 gram (0.000037 grain) of strychnine. 8 1 As to special effects of vanadic acid in this test, MANDELIN, 1883. As to a certain product of this oxidation, see p. 446. *In detailed experiments the following results were obtained (O. A. KIRCHMAIER, 1883: Contributions Chem. Laboratory Univ. of Mich., 2, 89; A. B. PRESCOTT, 1885: "Control Analyses and Limits of Recovery," Chem. News, 53, 78): Experiment. C.c. strychnine solution evaporated. Strychnine sulphate in grams. The fading purple. No 1 5.0 0000125 Distinct. 2 4.0 0.00001 < < 3 3 0000075 ii 4 2.0 000005 14 5 1.0 0.0000025 Good. Play of colors 6 0.8 0.000002 less marked. Faint. 7, 0.6 0.0000015 Uncertain. The solution was evaporated in a common evaporating-dish. Doubtless STRYCHNINE. 453 WORMLEY ' obtained very satisfactory evidence, by the use of the dichromate, from 0.0000013 gram (0.00002 grain) of strych- nine ; 0.000007 gram giving evidence as satisfactory as could be obtained from any larger quantity, and 0.0000007 gram, when deposited within a narrow compass, giving a distinct coloration. S. J. HINSDALE (1885) prefers the ceroso eerie oxide as an oxi- dizing agent, and reports a good play of colors from the 0.0000007 gram (0.00001 grain) of the alkaloid. It is to be understood that the limit of delicacy of the color test is wholly dependent upon the concentration of the alkaloid. A barely visible fragment of crystal of strychnine gives a good play of colors, but if dissolved in a few c.c. of alcohol, and the solution evaporated in a common dish, the residue would give probably a negative, possibly an uncertain, result. These statements of the smallest quantity of pure and unmixed alkaloid capable of iden- tification give no answer whatever to the question as to the smallest quantity of the poison, existing in a stomach or a por- tion of food or a plant, capable of recovery and identification. The limits of recovery receive attention, with methods of Sepa- ration, under 0, p. 461. Interferences with the color test (1) Substances diminishing the delicacy of the reaction. Brucine in equal quantity with strychnine prevents the coloration, unless the quantity of each be very minute, less than 0.001 grain, but a mixture of 0001 grain of each gives satisfactory evidence of strychnine (WORM- LEY). " The 0.01 grain of strychnine with 0.001 grain of brucine yields a very marked reaction, although somewhat masked" (Ibid.) Morphine is nearly as influential as brucine in dimin- ishing or preventing the color test. A residue from a solution of 01 grain each of strychnine and morphine gave WORMLEY a little indication of the presence of strychnine ; but a similar mix- ture of 0.001 grain of each of these alkaloids gave good evidence of strychnine ; while even a minute quantity of a mixture of three parts morphine to one part of strychnine gave a negative result. The absence of both these alkaloids, therefore, should be assured, if need be, by use of separative solvents, as directed un- der Separations (e). Of inorganic salts, nitrates- and chlorides have been named as diminishing the reaction. Organic matters had the residue from the 0.8 c.c. of No. 6, or even that from the 0.6 c.c. of No. 7, been brought within an area of two or three millimeters diameter, and moist- ened with much less than a drop of sulphuric acid, a good play of colors would have been obtained in trials 6 and 7. 1 ' Micro-chemistry of Poisons, 1 ' 1885, p. 5G4. I860: Chem News, i, 243. 454 STRYCHNOS ALKALOIDS. acting as reducing agents undoubtedly hinder or prevent the reaction, and sugar is especially influential in this regard. "While it is the rule that the test is to be applied in the absence of sub- stances not alkaloids, in practice it is sometimes difficult to be certain whether these matters are present or not. This question can be decided by a control-test as follows : Obtain by itself a narrow film of residue, equal to that tested for the result of analysis, by evaporation of a little of the recovered solution in a porcelain dish by itself. Add thereto (aside from the portions under analysis) say 1 c.c. of a solution containing in each c.c. from 0.0000025 to 0.000005 gram of strychnine sulphate (p. 452), and evaporate again. Or evaporate the 1 c.c. with the small portion of solution under analysis. This residue, with the added known quantity of strychnine, should give a distinct fading-blue coloration, as distinct as can be obtained by a test upon a residue from 1 c.c. of the strychnine solution unmixed. (2) Substances giving, in part, the same results obtained from strychnine in the fading-purple test, and presenting the so-called "fallacies" of this test. The greater number of these substances give a color with. sulphuric acid alone, and therefore their results are at once excluded from all indication of strychnine. Among these sub- stances may be named papaverine, thebaine, cryptopine, ber- berine, amygdalin, veratrine, and cod-liver oil. Aloin gives a greenish color, fading to yellow. Aniline, colorless with sulphu- ric acid alone, on adding the oxidizing agent presents yellowish or greenish tints slowly deepening to blue, which deepens, and (instead of fading) finally becomes blue-black to black. Gelse- mine, colorless alone with sulphuric acid, on adding dichrornate or other oxidizing agent gives a reddish-purple to cherry-red color, somewhat resembling that of strychnine. Hydrastine, but faintly yellowish with sulphuric acid, on adding the dichromate gives red to green color (LYONS, 1886). Curarine, the non-cry s- tallizable principle of worara, obtained from botanical sources allied to those of strychnine, is the only substance besides strych- nine which has been found to give the threefold result of the fading-purple test (WOEMLEY). The use of the permanganate, as an oxidizing agent, is more exposed to fallacy than the other oxidizing agents. If the oxidizing agent be mixed with the sul- phuric acid, and no parallel trial be made with sulphuric acid alone, the reaction of cod- liver oil may well be assumed as an indication of strychnine. The physiological test is to be placed second in order of the value of evidence. The data for this test with the frog, and the limits of quantity revealed by it, are given under b, p. 449. For STRYCHNINE. 455 the test the alkaloid is obtained in a neutral aqueous solution of a salt, as the sulphate. The taste of a graded dilute solution gives corroborative proof as to the presence and limit of quantity of strychnine (&, p. 448). According to WOKMLEY, a grain of a l-50000th solution of the alkaloid unmixed with other matters has a quite perceptible bitter taste ; and a drop of a l-10000th solution, even in mixture with a very notable quantity of foreign matter, usually has a decided bitter taste. Potassium dichromate solution, added to solutions of strych- nine salts not very dilute, gives a crystalline yellow precipi- tate of strychnine dichromate, (C 21 H 22 N 2 O 2 ) 2 H 2 C 2 O 7 (DITZLER, 1886), its slow formation being promoted by stirring. The crys- tals include octahedra and often bush-like groups. A drop of the solution, on a glass slide, may be treated with a drop of the dilute reagent, the mixture stirred with a fine pointed glass rod, and from time to time examined under a microscope with a low power. The precipitate is not soluble in excess of the reagent or in quite dilute acids. Solutions of strychnine salts in 1000 parts water do not yield an immediate precipitate, but from this and much more dilute solutions crystals can be obtained as di- rected above. The general reagents for alkaloids give precipitates of strych- nine. The precipitate with Mayer's solution, potassium mer- curic iodide, appears in a solution of a salt of the alkaloid in 150000 parts of water. The precipitate by phosphomolyb- date dissolves in ammonia without coloration. The precipitate by iodine in potassium iodide solution is obtained in very di- lute aqueous solutions (1 : 100000), reddish-brown, and soluble in alcohol. From the alcoholic solution somewhat characteristic crystals can be obtained. Alkali hydrates give crystallizable precipitates, soluble in excess only in the instance of ammonia. The ammoniacal solution gives fine crystals of the free alkaloid (a, p. 448). f Strychnine is noted, among alkaloids, for its stability under ordinary influences of decomposition. By action of chlorine or bromine, monochlorstrychnine or bromstrychnine is readily formed, as a substitution compound : by action of iodine, iodated hydriodides are formed, as addition compounds. By treatment with methyl iodide, the salt of methyl-strychnine, C 21 H 21 (CH 3 ) N 2 O 2 .HI, is easily obtained, as also is ethyl-strychnine by the same means. The conversion of strychnine into brucine remains under investigation. See Constitution of strychnos alkaloids, p. 446. 456 STRYCHNOS ALKALOIDS. e. Separations. Strychnine may be concentrated by evapo- ration of its solutions at 100 C., without loss or decomposition. In separation by solvents immiscible with water, chloroform and benzene take it up most abundantly as a free alkaloid (from al- kaline aqueous solutions). According to Dragendorff, petroleum benzin, though dissolving strychnine but very sparingly, may be profitably used to take it up from alkaline solutions as a means of [qualitative] separation from alkaloids soluble in chloroform or benzene and not soluble in petroleum benzin. 1 From acidu- lous solutions strychnine is not taken by any of the ordinary sol- vents immiscible with water (except as traces of the aqueous solution itself may be carried in solution with ether, chloroform, and amyl alcohol). From the Nux-vomica, in total alkaloids. The method of Messrs. DUNSTAN and SnoRT, 2 which has met with general appro- val, is as follows : Of the finely powdered nux-vomica seeds 5 grams are packed in the percolator of a continuous extraction apparatus, and treated actively with 40 c.c. of alcoholic chloro- form containing 25 per cent, of alcohol, until exhausted, which is usually accomplished in two hours or less. The chloroformic solution is agitated (in a separator) with 25 c.c. of a ten per cent, diluted sulphuric acid, the layer of chloroform drawn off and shaken again with 15 c.c. of the diluted acid, and the chloro- form layer drawn off. The formation of the chloroform layer is much facilitated by irently warming the mixture. The mixed acid solutions should be quite free from undissolved chloroform, and entirely clear. Chloroformic turbidity may be removed by adding a little chloroform and agitating slowly by gradually in- verting the separator. If need" be, the mixed acid solutions should be filtered, through a filter wet with the dilute acid, and the filter washed with a very little of the dilute acid. The total acidulous watery solution is now made alkaline with ammonia, and shaken out, in the separator, with 25 c.c. of chloroform. The clear chloroformic layer is slowly drawn off into a weighed or balanced beaker. If not readily obtained clear by subsiding, the chloroformic solution may be run through a small double filter wet with chloroform, washing the filter with a little chloro- form. The chloroform is gently evaporated, a constant weight 1 Wormley states that strychnine requires 12500 parts petroleum benzin for solution. Even if this hold good for the alkaloid freshly liberated, it still would require only 0.1 c.c. of the solvent to carry a quantity of the alkaloid easily identified by the color test. * 1883: Phar. Jour. Trans. [3] 12, 665. Given here with very slight addi- tions in details. STRYCHNINE. 457 of residue is obtained at 100 C. or on the water-bath, for which one hour is usually enough, and the weight of residue taken, for the quantity of total alkaloids. Prom preparations of Nux-vomica, in total alkaloids. DUNSTAN and SHORT present directions substantially as follows for standardizing an alcoholic percolate of nux-vomica in prepa- ration of a fluid extract of uniform alkaloidal strength. 1 The operation may be applied to the medicinal tincture or fluid extract. Take of the liquid 25 c.c., or one fluid-ounce, or other suitable quantity by weight or volume, according to the purpose. Eva- porate nearly to dryness over the water-bath. Treat the residue with water acidulated with sulphuric acid, in the proportion of 30 c.c. of a 7.5 per cent, sulphuric acid for each 6 to 7 grams of nux-vomica represented (1 f. oz. for each 100 grains), adding at the same time, for same quantities, about 7 c.c. (2 fluid - drachms) of chloroform. Agitate and warm gently. When the chloroformic layer has separated draw it off, add to the aqueous liquid ammonia to cause an alkaline reaction, and agitate with 15 c.c. (or \ f. oz.) of chloroform, warming as before. Draw off the chloroformic solution into a weighed dish, evaporate, dry over a water-bath for one hour, cool, and weigh for total alka- loids. For the Solid Extract the same authors dissolve 10 grains (or 0.6 gram) in \ f.- oz. (15 c.c.) of water, with the aid of heat, add 60 grains (4 grams) of sodium carbonate previously dissolv- ed in \ f. oz. (15 c.c.) of water, and agitate with \ f. oz. (15 c.c.) of chloroform, warming to obtain a separation. The chlorofor- mic solution of alkaloids is carefully drawn off, and agitated with \ f. oz. each of diluted sulphuric acid and water (or 30 c.c. of 5 to 7 per cent, sulphuric acid). The clear acidulous watery solution is made alkaline by adding ammonia, and agi- tated with \ f. oz. (15 c.c.) of chloroform. When the liquids have separated the chloroform is evaporated off in a weighed dish, the residue dried for an hour over the water-bath and weighed as total alkaloids. In applying this process to the resi- due from (say 25 c.c. of) the alcoholic preparations, Dr. A. B. LYONS 2 directs to shake out the acidulous liquid, first, with two successive portions of ether (25 c.c.), then with one portion of a mixture of one volume of chloroform with three volumes of ether, the shaking not to be too violent. The aqueous liquid made alkaline is extracted by the same ether- cliloro- 1 1884: Phar. Jour. Trans. [3] 13. 2 1885: Proc. Mich. State P/tar. Asso., 2, 183. 458 STRYCHNOS ALKALOIDS. form mixture, applying it in two successive portions ,(30 and 20 c.c.) Separation of Strychnine from Brucine. (1) By dilute al- cohol of sp. gr. 0.970 (about 21$ weight, 26$ vol.) In 1878 ' the author communicated results as follows : Solution requires For strychnine, 2617 parts of 21$ (weight) alcohol, 500 parts of 89$ alcohol. For brucine, 38 parts of 21$ (weight) alcohol, 22 parts of 39$ alcohol. When one part each of strychnine and brucine were digested one hour at ordinary temperature with 100 parts of alcohol of sp. gr. 0.970, filtered, and the undissolved alkaloid washed with 100 parts of the same alcohol, the residue of strychnine gave no qualitative test for brucine, but the brucine left on evaporating the filtrate gave a slight color test for strychnine (even in pre- sence of the excess of the brucine). (2) By precipitation with ferrocyanicle (DUNSTAN and SHOKT, 1883). The sulphates of the alkaloids in aqueous solu- tion acidified with sulphuric acid are precipitated with potas- sium ferrocyanide. The strychnine is entirely precipitated, boih when alone and when in the presence of brucine, while the bi u- cine is not precipitated unless in concentrated solution. ScHWEit- SINGER (1885) did not obtain good results by this method. Separation from Tissues and Foods in analysis for poi- sons. A weighed quantity (one part) of the material is placed in an evaporating-dish or wide beaker, finely divided under the points of a pair of sharp, bright shears, with moistening if need be to bring to a soft and homogeneous pulp, about an equal quantity of water containing about one per cent, of sulphuric acid is added, and the mass digested, with stirring, on the water- bath for 15 minutes. Four or five parts of well-rectified 90$ al- cohol are added, and the whole digested, with frequent stirring, at a little below the boiling temperature of the alcohol, for about an hour. The edges are to be kept free from dried residue. It is then cooled and strained through close muslin, or filtered through open filter-paper by the help of a filter-pump. The residue is digested, successively, with two smaller portions of alcohol, keeping the reaction of the mass constantly acid, the filtrates from all being received together in a wide mouthed flask, and the strainers or filters well washed with the alcohol. The filtered liquids are concentrated to a syrupy consistence, with 'Pro. Am. Pharm., 26, 806; Year-look of Phar., 1879, 97. STRYCHNINE. 459 occasional gentle rotation of the flask, preventing dried residues on the edges. Four or live parts of absolute or nearly abso- lute alcohol are added, the mixture shaken by rotating the flask, and, when cold, filtered into another flask, and the filter well washed with the absolute alcohol. The entire filtrate is evaporated on the water-bath to remove all the alcohol, when about two parts of water are added. If the reaction be not sharply acid to litmus, it is made so by adding a drop or two of diluted sulphuric acid. The mixture is filtered, and the resi- due and filter well washed with small portions of water, re- ceiving the entire filtrate in a small separator, or strong tube having a good cork. It is now shaken out with chloroform, in one or more portions, or as long as this solvent continues to ex- tract anything. The clear chloroform layer is drawn off by the separator, or forced out of the tube as water is delivered from a wash-bottle, the tubulated stopper fitted for that purpose having an adjustable delivery tube brought to the conical bottom of the container. The chloroform solution is washed once or twice with a little faintly acidulous water, and the washings added to the aqueous liquid. The chloroform solution is reserved for any tests desired. The aqueous solution is made distinctly alkaline by adding ammonia, and exhausted by shaking out with from three to five portions of the chloroform. The united chloro- formic liquids are to be obtained perfectly clear. A zone of par- tial emulsion next to a supernatent watery layer may be resolved by introducing into the zone a c.c. or so each of fresh chloro- form and of water, and tapping the separator. If need be, the chloroform so added may be made slightly alcoholic. Also, a little portion of emulsified chloroform may be washed with chlo- roform on a filter wet with the same solvent. Now an aliquot part of the total chloroformic solution (from the alkaline liquid) may be evaporated for preliminary tests. The residue so ob- tained is usually colored and loaded with substances not alka- loids. When no other alkaloid than strychnine is sought, the residue from evaporation of the (remaining) chloroform solution may be purified ?s follows: The residue is treated with concen- trated sulphuric acid, one or two drops, or only enough to moisten the whole, covered and heated on the water-bath, or, better, heated in an oven at 100 C., avoiding any higher tempe- rature, for an hour or so. To the carbonized mass, when cold, barium carbonate is added, to neutralize nearly all the acid, still leaving an acid reaction. The little mass is now exhausted with small portions of water, and the solution and washings filtered into a small separator. The aqueous solution is now made alka- 460 STRYCHNOS ALKALOIDS. line by adding ammonia, and exhausted by repeatedly shaking out with chloroform in small portions. The entire chloroform solution is received in a graduated cylinder, and aliquot parts are evaporated in small porcelain and glass dishes, for the several tests, and for trial as to qualitative limits, also, if desired, for volumetric estimation. The residues will contain some ammo- nium sulphate, the crystals of which are likely to be seen in mi- croscopic examinations. To obtain a portion free from ammo- nium salts and from sulphates in general, treat one of the residues with water and barium carbonate, evaporate to dryness, take up with warm alcohol, filter, and evaporate the alcoholic solution, for another residue. Strychnine may be separated from the Urine by evaporat- ing the acidulated liquid to a syrup, stirring with strong or abso- lute alcohol, filtering and washing well with the same alcohol, concentrating the filtrate to a syrup, which is dissolved in water enough to make a limpid solution. This is washed (while aci- dulous) with chloroform ; then made alkaline by adding ammo- nia, and washed with one or more portions of chloroform. The chloroformic solution is evaporated, either all together or in aliquot portions, for direct tests upon the residue or for further purification, as directed on p. 459. As to the occurrence of strychnine in the urine, following administration, results are stated under #, p. 449. Recovery from Alcoholic Beverages. Messrs. GRAHAM and HOFMANN, in 1852, made extensive analyses of the ales and beers of Great Britain for strychnine, as follows : Half a gallon of the ale was shaken with 2 oz. of animal charcoal, and, after standing 12 to 24 hours, filtered through paper. The drained charcoal was boiled half an hour in purified alcohol, and the fil- tered alcohol distilled off. The watery residue was made alka- line with potassa, and agitated with an ounce of ether [chloro form]. The residue from evaporation of the ether was tested. Taking ^ grain of the alkaloid in J gallon of the malt liquor, the operators invariably obtained the color test in the final residue. Probably a preferable procedure would be the treatment directed above for separation from the urine. With distilled spirits, such as whisky, the same operation (last referred to) is advisory, the alcohol being first distilled off, when the slight quantity of resi- due usually renders the operation a very simple one. Single cases of the detection of strychnine in beer in Eastern Europe have been reported. There is no evidence, and no probability, that strychnine has ever been used in the sophistications of dis- tilled spirits. STRYCHNINE. 461 Limits of Recovery from complex organic matter. J experiments of Mr. Kirchinaier, with the author's co-o -From the experiments of Mr', forchmaief, with the author's co-opera- tion, 1 it appeared that the limits of analytical separation, by a process essentially the same as that just detailed, were as follows : With 50 grams of meat, the loss of strychnine was for one part of meat, 0.00000795 part of strychnine ; or for one part of the alkaloid, 125786 parts of the tissue-material. 2 That is to say, in separating strychnine from an avoirdupois pound of tissues the loss of alkaloid is from one thousand to two thousand times the least quantity needed for certain identification (p. 452). The deposition of strychnine , in various organs of the living; body receives statement under J, at p. 450. It is capable of recovery from partly decomposed organs some time after death, subject to limitations not yet very definitely established. No other alkaloidal poison resists destruction in the interred body any better than strychnine, probably none other resists as well. Yet it is by no means indestructible when contained in putrefactive tissue. The data obtained by adding strychnine to tissues, and recovering it after some months of putrefactive decomposition, are but imperfectly applicable to cases of poisoning by the al- kaloid, because of "the attenuation that results from absorption and elimination. Wormley states 3 that " the longest period in which the analysis furnished positive evidence of its presence in the exhumed human body is 43 days after death (Ann. d?Hyg., 1881, 359)." But in the case of Magoon, in New Hampshire, 1875, Drs. Hayes and E. S. Wood, of Boston, found strychnine in the body of a woman advanced in years, exhumed one year and three days after death; and the analysts reported 0.15 grain in the stomach, 0.23 grain in the liver, and presence of the alka- loid in the intestines. Death had occurred in less than an hour after administration of an unknown quantity of the poi- 1 "Control Analyses and Limits of Recovery in Chemical Separations," 1885: Chem. News, 53, 78. Contributions from the Chem. Lab., Univ. of Midi. , 2, 91. 2 Experiment 4, 5, 5 gra i ms m( jat, 0.00016 stryc 0.00012 hnine, good color- faint test. ' 6, < 0.00008 very faint 7, 0.000064 negative 8, i 9, i 0.0004 0.0002 good faint 10, ' 0.00016 negative 3, 5 br ad, 0.0001 good 4, ' 0.0008 faint 5, 1 0.0006 very faint 9 e\ J . .1 6, t 0.0004 - *t -4 nr\f negative 3 2d ed. " Micro-Chem. Poisons," 1885. 462 STRYCHNOS ALKALOIDS. son, in a tumbler of hot liquid of extreme bitterness. In 1875 Prof. WOBMLEY made analysis of the stomach and liver seven months after death, and the chemical tests gave no evidence of strychnine, although the final residues had a bitter taste. Death had occurred within two hours, and the symptoms and other proofs were such that there was a conviction for poisoning (Ohio v. Dresbach, 1881). Buchner, Gorup-Besanez, Wislicenus, and Ranke (1881) made a series of experiments upon seventeen dogs, killed, each, by 0.1 gram of strychnine, and buried from 100 to 330 days before analysis. In no case did the chemical tests show the presence of strychnine, though the physiological test, with frogs, obtained tetanic convulsions, and the residues had a bitter taste. f. Quantitative. Strychnine is estimated gravimetrically by weight of the anhydrous alkaloid, dried at 100 C. A volu- metric estimation (less exact than the gravimetric) is obtained by Mayer's solution, each c.c. of which represents 0.016T gram of strychnine (%-^^ of 334, in grams). The end of the reaction is distinct, and the precipitate settles fairly well in acidulated water, but settles better in a concentrated solution of potassium chloride (DRAGENDORFF, 1874), when each c.c. of the entire solu- tion dissolves 0.00216 gram of the precipitate (ibid.) The composition of the precipitate as CoiHgg^OoHIHglo was near- ly sustained by the determinations of mercury and of iodine communicated by the author in 1880. 1 This chemical formula corresponds to 36.47$ strychnine in the precipitate. Dragendorff gives a gravimetric trial by washing, drying, and weighing the precipitate, whereby there was a loss of only 1.8$ on the basis of this formula. Though more constant than the greater number of alkaloidal iodomercurates, the precipitate is not the most favora- ble form for gravimetric purposes. And in the volumetric de- termination the solution is to be made of 200 parts to 1 of the alkaloid. g. Tests for Impurities. " Strychnine should not be red- dened at all, or at most but very faintly, by nitric acid (absence of more than traces of brucine)." May be colored yellowish but not red when rubbed with nitric acid (Ph. Germ.) Not colored by nitric acid (Br. Ph.) A more strict exclusion of brucine is effected by washing the free alkaloid with dilute alcohol (sp. gr. 0.970) to separate the brucine, as described on p. 458, the residue 1 CHEM. LAB. UNIV. MICH.: Am. Chem. Jour., 2, 297-99; Jour. Chem. Soc., 42, 664. I BRUCINE. 463 from evaporation of the filtered dilute alcohol being tested with nitric acid. 1 Of ten samples of commercial strychnine, treated in this way, all but two gave tests for brucine. BRUCINE, C 23 H 26 NoO 4 394. Crystallizes with 4H 2 O, 15.45$. For constitution of the alkaloid see p. 446 ; yield in nux-vomica, p. 447. Brucine is identified by its color-tests with nitric acid and other additions, its dichromate precipitate, its crystalline forms, and its physiological effects as a convulsent (d). It is distin- guished from strychnine by a negative result in the " fading- purple " test, and the positive reactions with nitric acid, etc. (d). It is separated with strychnine, and from strychnine, as de- scribed on pages 456, 460 ; and is estimated gravimetrically or volumetrically (f). a. Transparent or colorless, oblique, four-sided crystals, or in groups of delicate needles, varied in form according to the solvent and the conditions. The crystals effloresce in dry air, and on the water-bath the alkaloid soon becomes anhydrous. It melts at 151 C. (BLYTH, 1878), at 115.5 C. [when anhydrous?] (Gur). It gives a decomposition-sublimate in the " subliming cell " at 150 C. and above (BLYTH), at 204 C. (GuY). b. Brucine is extremely bitter. In effects in general it re- sembles strychnine, but a far greater quantity is required for the same effect. T. L. BRUNTON (1885) found that it is excreted far more rapidly than strychnine, so rapidly that when given by the stomach to animals pure brucine has little effect. Given hypo- dermically it causes death by convulsent action. WORMLEY states that the effect of brucine is that of strychnine, with T * the intensity. c. Effloresced brucine dissolves in 850 parts cold or 500 parts boiling water, the crystals being considerably more soluble. Very soluble in alcohol, absolute or aqueous. As to its solubility in certain strengths of dilute alcohol, see page 458. Almost insoluble in ether, soluble in chloroform, benzene, or amyl alcohol. The ordinary salts of brucine are soluble in water and in alcohol, not in ether. d. Nitric acid gives a red color with brucine. For the proper intensity the acid should be concentrated, near 1.42 spe- cific gravity, and the alkaloid should be dry and placed over a 1 The author and A. D. Smith, 1878: Proc. Am. Pharm., 26, 807. 464 STRYCHNOS ALKALOIDS. white ground. If the alkaloid be concentrated at one point, and minute in quantity, it may be treated with less than a drop of the acid, added at the point of a sharp glass rod. On standing, or heating, the color changes to yellowish ; on evaporating to dry ness the red color returns in the residue. About 0.0000013 gram (0.00002 grain) is the limit of quantity for distinct colora- tion, with the best concentration. Sulphuric acid alone applied to the dry alkaloid causes a faint rose color. If in a drop of the rose solution of the concentrated acid a minute fragment of po- tassium nitrate be placed, an orange-red color is obtained. If the concentration be of the best, about the 0.00003 gram is suf- ficient for a sensible reaction. If the dry alkaloid or its salt be treated with a drop or just wet with nitric acid, as above direct- ed, warmed till the color turns to the yellow, then cooled and touched with a drop or less of good solution of stannous chlo- ride, a purple to violet color is obtained. Excess of either the nitric acid or the tin salt is to be avoided. The heating is only necessary to bring out the full delicacy of the reaction. Sodium sulphide solution (by saturating caustic soda solution with H 2 S) may be used instead of stannous chloride. The reaction with tin salt may be recognized with the 0.00001 gram of the alkaloid. Of the three allied color- tests just described, the last is the most characteristic, and the agreement of the three furnishes quite conclusive proof of identity, with distinctions from morphine, narcotine, and other alkaloids. In the sulphuric acid and di- chromate test made for strychnine, brucine slowly reduces the chromic acid, with colors changing from dull orange to greenish, without the least resemblance to the "fading purple." Froehde's reagent gives a red to yellow color. A solution of brucine in dilute sulphuric acid, touched with very dilute dichromate solution, gives a red color changing to duller tints. Mer- curous nitrate (free from excess of nitric acid) gives a re- action somewhat like that of nitric acid, but developed only on heating, the color being carmine, and permanent on evaporating to dryness. Solution of a brucine salt, with solution of potassium dichro- mate, yields a yellow crystalline precipitate of brucine chromate, in groups of bent needles, formed in quite dilute solutions, and somewhat characteristic. The precipitate dissolves in nitric acid with a red color. The general reagents for alkaloids give the customary preci- pitates with brucine. Very dilute solutions give the precipitate with iodine in potassium iodide solution. The precipitate form- ed by phosphomolybdate is of an orange tint, dissolving in am- TANNINS. 465 monia to a yellow-green solution. The caustic alkalies cause a precipitate, gradually becoming crystalline, and somewhat sol- uble in ammonia. The physiological test of brucine, with the frog, is qualita- tively nearly the same as that for strychnine (pp. 454, 449), but a very much larger quantity of brucine is required for the same effect. e. Separations. Brucine may be obtained from an aqueous or other solution by evaporation at 100 C., without loss. The aqueous solution of its salts may be washed with any of the ordinary solvents immiscible with water, its salts not being solu- ble in these solvents. On making the aqueous liquid alkaline, chloroform or benzene serves well as a solvent, and amyl alco- hol also takes it up. Petroleum benzin dissolves it to some extent. The separation of brucine with strychnine, from nux-vomica and from its preparations, is described under Strychnine, p. 456. The separation from strychnine is given at p. 458. In analysis for poisons, brucine will be obtained with strychnine by the methods detailed at pages 458, 460. f. Quantitative. Brucine is estimated gravimetrically in the same manner as strychnine (p. 462), the residue of free al- kaloid being dried at 100 C. to a constant weight, when it can be weighed as anhydrous In the volumetric method with May- er's solution, Mayer's factor for 1 c.c. of the solution was 0.0233 gram of the alkaloid. SULPHOCARBOLIC ACID. See PHENOL, p. 405. TANNINS. Tannic Acids. Gerbsauren. Vegetable educts of an astringent taste, amorphous or obscurely crystal- line solids, not volatile without change, of very slight acid power, and freely soluble in water and in alcohol. They give blue or green precipitates with ferric salts, and thick precipitates with gelatin, albumen, and starch paste. In most cases they pre- cipitate the alkaloids, likewise tartrate of antimony and potas- sium, and are dissolved but sparingly by dilute mineral acids. They are all strong reducing agents, giving reductions with Fehling's solution, with permanganate, and with salts of silver and of gold. The greater number of them convert animal mem- brane into leather. They are darkened and decomposed by al- kali hydrates. In solutions they are instable. There are many diversities of character and composition of 4 66 TANNINS. tannins. The best known of these differences may be stated as follows : (1) Glucoside-tannins. When boiled with dilute mineral acids, yield (a) a erystalliza- ble acid or its anhydride, or (&) a phlobaphene (a re- sin-like body), along with a glucose. 1 (2) Iron-bluing tannins. With ferric salts give blue to black precipitates or colors. The ferroso-ferric solutions, slightly basic, give the best reactions. Mineral acids dissolve and decolor. (3) Tannins not tanning agents. Do not form leather, nor preserve animal membrane, though precipitating solu- tions of gelatin (WAGNER 3 ). (4) Tannins which, in sublim- ing, or in fusing with po- tassium hydrate, yield a trihydroxyphenol, C 6 H 3 (1) Tannins not glucosides. For determination whether a glucoside or not, see be- low. (2) Iron - greening tannins. 8 With ferric (basic) salts give greenish precipitates or colors. Brown colors sometimes obtained. Tints varied by conditions. (3) Tanning materials. Change animal membrane into leath- er, not putrescible. Also precipitate solutions of gela- tin. (4) Tannins which, in sublim- ing, yield a dihydroxyphe- noi, C 6 II 4 (OH)o, and, on fusing with potash, yield an 1 " I have arrived at the curious result that tannic acid, when acted upon by acids, yields, together with gallic acid, sugar, so that henceforth tannic acid may be classed with the conjugate sugar compounds." STRECKER in a letter to Hofmann in 1853. In 1872 SCHIFF found the product to be primarily digallic instead of gallic acid. 2 Of the iron-greening tannins examined only willow-tannin was found to be a glucoside. STENHOUSE, 1861. " Tannins in the green parts of plants, ac- cording to their nature, affect iron solutions differently; that which colors iron green is apparently an oxidation product of that which colors iron blue, and the author thinks that the latter, under the influence of transpiration, breaks up into the former modification and sugar." E. JOHANSON, 1879: Jour. Chem. Soc., 26, 161, from Arch. Pharm. [3] 13, 103-130. Regarding iron colors with plienol hydroxyl, see SCHIFF as quoted under Carbolic Acid, in reaction with Ferric Chloride, p. 399. 3 Zeitsch. analyt. Chem., 5, 1. Wagner states that the pathological tan- nins of the galls of species of Quercus and Rhus do not form true leather or preserve animal membrane from putrefaction. LOWENTHAL (1877: Zeitsch. anal. Chem., 16, 47) found that precipitates of gelatin with gallotannin and sumach-tannin, standing under water for two years, still gave no odor of putre- faction. TANNINS. 467 (OH)o, such as Pyrogallol acid, as Protocatechuic acid, (HLASIWETZ). C 6 H 3 (OH) 2 CO 2 H (HLASI- WETZ). (5) Pathological tannins. (5) Physiological tannins. Formed in punctured vege- From uninjured vegetable table tissues. Gallotannins tissues (Wagner). Include (WAGNEK, 1866 '). Includ- various glucosides and iron- ing sumach-tannin (&TEN- bluing tannins. HOUSE, 1861). In testing for glucoside tannins, the solution, not very di- lute, is first tried as to its deportment with f erroso-f erric solution, gelatin solution, cinchona sulphate solution, and Fehling's solu- tion. Sulphuric acid equal to one or two per cent, is now added to a portion, and the liquid is boiled for an hour or two. Or hydrochloric acid is added, to give about the same percentage of real acid, the liquid sealed up in glass tubes and heated at 100 C. for an hour or longer. A portion of the liquid is now dropped into cold water, to see whether sparingly soluble fer- mentation products may precipitate, so that they can be re- moved by filtration. Otherwise the liquid may be shaken w T ith successive portions of ether, or chloroform, or acetic ether (DRAGENDORFF). The liquid is now nearly or quite neutralized by the addition of fixed alkali hydrate, and tested, as at first, with f erroso-f erric solution, gelatin solution, cinchona sulphate solution, and Fehling's solution, noting if these results differ from those obtained before boiling. The production of glu- coses may be further investigated, by a fermentation test, with yeast (see under Sugars), and by optical examination as to rota- .tory power. "Tannins are precipitated by lead acetate, copper acetate, and zinc ammonio chloride, and by the salts of nearly all the non- alkali metals. The removal of tannins from solutions may be effected by digesting the liquid with recent ferric hydrate, zinc oxide, copper oxide, or lead oxide, and filtration. Also by maceration with animal membrane or rasped hide ; or by filtra- tion through purified animal charcoal. Gelatin gives better precipitates in solution saturated with ammonium chloride or sodium chloride, and the addition of sulphuric or hydrochloric acid further helps the separation of the precipitates. Separa- tions by acetic . ether, and non-precipitation, are given under Gallotannin. 1 See note on p. 466. 468 TANNINS. ESTIMATION OF TANNINS and Valuation of Tanning Mater- ials. (I) Method of LowENTHAL. 1 Titration by a perman- ganate solution, before and after removal of the tannin by gelatin in solution saturated with sodium chloride and acidi- fied. Both titrations made in presence of much indigo solution, which regulates the oxidation and serves as an indicator. The method employs the following-named solutions : (a) Permanga- nate of potassium solution : 1.333 or (Kathreiner) 1.000 gram of the crystallized salt to 1 liter, (ft) Indigo solution: 6 grams pure precipitated indigo, and 50 c.c. concentrated sulphuric acid, per liter. There should be added sufficient of the indigo to re- quire for itself two-thirds of all the permanganate used (Kathrei- ner). (c) The solution of Glue and common salt is made by macerating 25 grams of good transparent glue in cold water, then heating to dissolve, making up to 1 liter, and saturating with good common salt. It should be filtered clear when used. (d) The acidulated solution of Common Salt is a saturated solu- tion with addition of 25 c.c. of sulphuric acid in a liter. In the analysis 20 to 25 grams of bark, or 10 grams of sumach or valonia, are boiled with portions of water until fully exhausted, and the solution, when cold, made up to 1 liter. Of this 10 c.c. are diluted to 800 or 1000 c.c., 25 c.c. of the indigo and acid solution are added, the mixture treated with the permanganate solution, drop by drop from the burette, with constant stirring, until the blue color changes to a clear yellow, showing no green tint, and the number of c.c. of permanganate is noted. Another 25 c.c. of the indigo and acid solution are diluted to the same volume made before, and the titration with permanganate re- peated, when this result is subtracted from that first obtained, to obtain the quantity of permanganate required for the 10 c.c. of tannin solution. The tannin, as well as gallic acid, if present, are mainly oxidized before the indigo, and therefore oxidized '1877: Zeitsch. anal. Chem., 16, 33; Jour. CJiem. Soc., 31, 745. KA- THREINER, 1879: Dingler's polyt. Journ., 227. 481; Zfitsch. anal. Chem., 18, 112; a report fully sustaining this method, and defending it against a criticism in Mohr's Titrirmethode. H. R. PROCTER, 1877: Chem. News, 36, 58; Jour. Chtm. Soc., 32, 807, "the most practical method of tannin analysis yet dis- covered." NEUBAUER, Zeitsch. anal. Chem., 10. 1 (1871), after an elaborate review of methods, gives preference to this. B. HUNT (1885: Jour. Soc. Chem. 2nd., 4, 263) reports at length upon this process, and advances modifications, some of which are given in a foot-note further on. Without these modifica- tions Mr. Hunt finds that a considerable quantity of gallic acid may cause too high a result for tannin. Lftwenthal made the first report of titration with per- manganate in presence of indigo in 1860: Jour. /. prakt. Chem., 81, 150. The volumetric use of permanganate was introduced by MONIER: Compt. rend., 46, ESTIMATION OF TANNINS. 469 promptly while the permanganate is concentrated. A portion of 100 c.c. of the tannin solution is now treated with 50 c.c. of the glue and common salt solution, and, after stirring with 100 c.c. of the acidulated solution of common salt, again stirred, set aside several hours, and filtered l The filtrate should be perfectly clear. Of this filtrate 50 c.c. (containing 20 c.c. of the tannin solution) are mixed with 25 c.c. of the indigo solution, and the mixture is titrated with the permanganate solution. Another 25 c c. of the indigo solution, diluted as in the last trial, and titrated, will give the number of c.c. of permanganate to deduct for reduction by indigo. The remainder will be the number of c.c. of permanganate taken by substances other than tannin in 20 c.c. of the tannin solution. Therefore one half of this num- ber of c.c. will be the number to deduct for decoloration of the permanganate by substances other than tannin in 10 c.c. of the original tannin solution. In the removal of the tannin, both the gelatin solution and the acid and salt solution must be added in sufficient quantity to give a perfectly clear filtrate. 2 The acid and salt solution must not be brought in contact with the gelatin solution before the latter is fully mixed with the tannin solution. The permanganate is to be added slowly, in a white porcelain dish, giving for reduction as much as four minutes with the original solution, and six minutes with the filtrate. It is better to let the gelatin precipitate stand as much as half an hour be- fore filtering ; if filtered earliei the filtrate will consume more permanganate (HEWITT). In preparing the solution from oak- bark or from galls a few drops of acetic acid may be added for preservative effect, and with each portion of water the material may be boiled ten or fifteen minutes. It must not be forgotten that tannins are instable. Duplicate titrations should be made, and should agree to within 0.1 or 0.2 c.c. of permanganate. 'B. HUNT (1885) proceeds as follows: 100 c.c. of the tannin solution is treated (in a flask taken dry) with 50 c.c. of a solution of 2 grams of gelatin in 100 c.c. (freshly filtered). The flask is shaken, and 50 c.c. of a saturated solution of common salt (containing 50 c.c. of undiluted sulphuric acid per liter) is added, together with a little kaolin or barium sulphate. The solution filters clear. 2 Lowenthal finds only a very small and nearly constant reduction of per- manganate by gelatin solution, and ascribes this" slight reduction to certain oxidizable substances with the gelatin. He infers that these oxidizable sub- stances are precipitated by tannin before all the gelatin is precipitated. By adding 20 c.c. of the gelatin solution the indigo solution consumed 0.4 c.c. more of permanganate solution. Different kinds of gelatin give only a little difference of results. Kathreiner proposes to deduct one-half of the perman- ganate found to be consumed bv the given quantity of gelatin solution (Zeit anal. Chem., 16, 33, 18, 114). * 470 TANNINS. The following schedule of quantities may be changed at dis- cretion : For 10 c.c. tannin solution, with 25 c.c. indigo solution a c.c. For the same again a' c.c. For 25 c.c. indigo solution, diluted as before. . b c c. For oxidizable substances in 20 c.c., tannin sol. a -f- a' b = in. For 50 c.c. filtrate from 100 c.c. tannin sol., 50 c.c. glue sol., and 100 c.c. acid and salt solution c c.c. For another 50 c.c. of the filtrate c' c.c. For 50 c.c. indigo solution, diluted as last above J' c.c. For oxidizable substances other than tannin in 20 c.c. tannin solution . . . c For tannin in 20 c.c. original solution So far we have only the permanganate value of the original solution, and, from this, of the material taken to be estimated. The permanganate value serves to compare articles containing the same tannin with each other, as oak-bark with oak bark, galls with galls, etc. A comparison of oak-bark with galls must be taken with some reservation, as different tannins cannot be as- sumed to act with the same equivalent. The permanganate so- lution may be compared with a standard solution of the purest gallo-tannic acid to be obtained, or with any article of tannin of known value. The conditions of time, temperature, and dilu- tion must be kept constant in all comparisons, both in extracting the material and in titrating the solutions. According to the experiments of NEUBAUER, in 18 71, 1 63 grams of crystallized oxalic acid (equivalent to 31.4 grams of absolute potassium per- manganate) correspond to 41.57 grams purified gallo-taniiin. 7 That is, 10 c.c. decinormal oxalic acid solution reduce as much permanganate as 0.04157 grams of Neubauer's purified tannin. Oser has found that the same quantity of oxygen is required for 1 part of gallo-tannin and for 1.5 parts of oak-bark tannin. Then 10 c.c. decinormal oxalic acid solution correspond to 0.06235 grams oak-bark tannin. These factors serve provisionally, Neu- bauer's for galls, sumach, and myrabolans ; Oser's for oak- bark, 1 Zeitsch. anal. Chern., 10, 3. 2 This is near the ratio of 4(H 2 C 2 4 .2H 2 0) to C 14 H 10 O 9 ; 504 to 322; 63 to 40.25. The ratio to Schiff's natural tannin glucoside is that of 8(H 2 C 2 4 . 2H 2 0) to C 34 H 2e O 22 ; 63 to 49.25. ESTIMATION OF TANNINS. valonia, and chestnut. No interference in this estimation (with the specified dilutions) by presence of acetic acid, citric acid, tar- taric acid, malic acid, cane-sugar, dextrin, gum, fat, caffeine, or urea (Cecil '). Other agents for removal of the tannin in connec- tion with Lowenthal's process have been tried. SIMANDS (1883) proposes to use the gelatigenous tissue of bones, prepared by digesting bone in dilute hydrochloric acid and washing away the earthy chlorides. The tannin solution is macerated with the prepared tissue until the tannin is removed. NEUBAUER 3 re- moves tannin by purified animal charcoal, which he finds not to remove pectous substances. Lowenthal originally used chlori- nated lime instead of the permanganate. (2) Method of GERLAND, improved by RICHARDS and PAL- MER. 3 Volumetric precipitation by potassium antimony tartrate in presence of ammonium acetate. Either acetate or chloride of ammonium causes a much closer precipitation of tannin, and pre- vents precipitation of gallic acid. The standard solution of Tar- trate of Antimony and Potassium contains 6.730 grams of the salt dried to a constant weight at 100 C. in one liter. Of this 1 c.c. corresponds to 0.010 of digallic acid. The solution of Ammonium Acetate was prepared by Richards and Palmer by saturating glacial acetic acid with stronger water of ammonia. The material for analysis is dissolved or exhausted so as to fur- nish a solution of 150 c.c. to 300 c.c. in volume and strong enough to contain 0.3 to 0.9 gram of tannin. The entire solu- tion from the weighed portion of material is now divided into three (or four) aliquot parts. To one division the standard solu- tion of antimony is added from the burette, in probable excess, and to a second division a quantity sure not to be an excess is added. To each liquid the acetate of ammonium solution is added, in proportion of 1 c.c. (of the strong solution just speci- fied) to about 25 c.c. of total liquid. The precipitates are left to settle, and as soon as clear liquids appear a drop is taken from each division and tested on a hot porcelain plate with a drop of 1 Zeitsch. anal. Chem., 7. 134. 2 1871: Zeitsch. anal. Chem., 10, 1. SGERLAND, 1863: Chem. News, 8, 54; Zeitsch anal. Chem., 3, 419. GAUHE (1863: Zeitsch. anal. Chem., 3, 131) reports upon the method, with ob- jection on ground of the difficulty of fixing the end of the reaction, and ad- vises to test a filtrate of the titrated liquid for antimony by zinc and hydro- chloric acid upon platinum foil. RICHARDS and PALMER, 1878: Sill. Am. Jour. Sci. [3] 16, 196, 361 modifications, in the substitution of ammonium acetate instead of chloride, and in testing for excess of antimony. These authors report elementary analyses of the precipitates. 472 TANNINS. solution of sodium tliiosulphate. If the antimony have been added in excess the orange precipitate of antimonious sulphide will appear. By continued tests of the second division the point of least excess of antimony capable of recognition is found ap- proximately. This point is then iixed with exactness by tests of the third division (and, if provided for, the fourth division). The loss by taking out test-drops is reduced to a minimum in the final titrations. It is better to carry the titrations to a decided orange tint for excess of antimony, and then subtract 0.5 c.c. from the reading of the antimony solution as a correction for this excess. The c.c. X 0.01 = the grams of tannin counted as digallic acid. Gallic acid does not interfere in this method, owing to the ammonium acetate. Various colors occurring in tanning materials enter into the precipitates, some of them uniting with the antimony instead of the tannin, and therefore appearing as tannin in the results. Two classes of color sub- stances are indicated by the experiments of Richards and Palmer, one closely allied to quercetin, and both related to tannins and tanning agents. With this method, as with Lowenthal's, true comparisons between different tanning agents, as between oak- bark and hemlock-bark, are not likely to be obtained. The for- mula of the typical precipitate of digallic acid is presented by the authors last named as Sb (C 14 H 8 O 9 ) 3 .6IL>O. It therefore demands ZKSbOC^O^ X 323 = 640) to 3C 14 H 10 O 9 (3 X 322 = 966). The authors' analyses of precipitates of pure tannins support the formula very well. (3) HAGER'S method with copper oxide. 1 The addition of oxide of copper to take up the tannin, which is estimated from the increase in weight of the oxide, or (as in Hammer's plan) by the decrease in specific gravity of the solution. The powdered material is extracted first with water and then with alcohol, the concentrated solution treated with alcohol and filtered, the filtrate evaporated to remove all the alcohol, diluted with water, filtered, and the solution made up to a determinate volume, of which the specific gravity may be taken. Recently ignited oxide of copper, equal to at least five times the weigh! of the tannin to 1 FLECK, in 1860, used precipitation with acetate of copper and volumetric estimation of the excess of copper in solution, by potassium cyanide. SACKUR, Q-erberzeitigung, 31, 32, directed the Ignition of the copper precipitate, and WOLFF, 1862: Zeitsch. anal. Chem , z, 103 ; from twenty-eight analyses gave 1 to 1.304 as the ratio between ignited copper oxide and tannin in the precipitate formed by acetate of copper. To exclude gallic acid Fleck treated the pre- cipitate with ammonium carbonate solution. Hager, in his " Untersuchun- gen," vol. ii. p. 115, gives the method here presented. ESTIMATION OF TANNINS. 473 be found, is now added^the mixture warmed for an hour, and set aside, with occasional agitation, for a day. The filtrate may now be made up to the determined volume, the specific gravity taken, and the table consulted for percentage of tannin corre- sponding to difference of gravity. The precipitate may be washed clean, dried on the water-bath, and weighed, the increase in weight showing the quantity of tannin. Gallic acid will be included. The method seems open to danger of loss of tannin by decomposition, especially with oak-bark tannin. (4) The method of HAMMER \ has been much used for com- mercial analyses, but gives untrustworthy results. The water solution of the material, made up to a determinate volume, is macerated with dried rasped hide, in quantity at least five times as much as the tannin to be found, until the tannin is wholly removed from solution. The filtered liquid is made up to the volume before noted, and the specific gravity is to be taken both before and after the removal of the tannin. Difference in spe- cific gravity -f- 1 = specific gravity for per cent. A table of per- centages of gallotannin is given at p. 477. Pectous substances are absorbed by the rasped hide, a cause of error unless the pec- tous substances are removed by precipitation with alcohol, which is then evaporated. (5) The method of WAGNER 2 gives insufficient results with oak-bark, but is serviceable for various manufactured forms of tannins. It is a volumetric precipitation by an alkaloid. 4.523 grams of good sulphate of cinchonine, with 0.5 gram sulphuric acid and 0.1 gram acetate rosaniline or f uchsine, are dissolved in water to make one liter. Each c.c. of this solution precipitates 0.01 gram tannic acid. One gram of solid material is obtained in clear solution of about 50 c.c. measure. To this the standard solution of cinchonine is added, the color being thrown down in the precipitate. By a quick agitation the precipitate soon set- tles. When the tannic acid is all precipitated, the aniline color appears in solution. One gram having been taken, each c.c. of the volumetric solution indicates 1 per cent, of tannic acid. Gallic acid is not precipitated by cinchonine. CLARK 3 has tried a modification of this method for cases of colored liquids which ! 1860: Jour. f.praU. Chem., 3, 159. 2 1860: Zeitsch. anal. Chem., 5, 9. As to limits and deficiencies of this method see BRAUX, 1868: Zeita'h. anal, Chem., 7, 139. 3 Contributions from Cliem. Lab. of Univ. of Mich., 1870: Am. Chem., 7,44. fc 474 TANNINS. obscure the aniline red. It is the use of the standard solution of cinchonine in some excess, filtering, washing sparingly, and ti- trating back in the filtrate with Mayer's potassium mercuric iodide solution. This solution may be compared with the cin- chonine solution, or the factor of 0.0124 gram of cinchonine sulphate for each c.c. of Mayer's solution may be used. Among the many other methods for determination of tannins re those with use of Acetate of Lead as a precipitant, with alco- ol ; ' bone gelatin solution with alum ; a and ferric acetate so- lution with sodium acetate. 3 Upon the adaptation of the several methods of estimation to the several well-known different tan- nins, see GUNTHEK, 1870. 4 For estimation of tannin in leather HAGER'S method may be employed. For the most part gallic acid is obtained from leather instead of tannic acid. 6 Of distinctly known tannins, or tannic acids, the limits of this work permit only the following to be described. GALLOTANNIN. Nutgall-tannin. Gallusgerbsaure. Chiefly Digallic acid, or Gallic anhydride, n TT n C 6 H (OH) CO 2 H ) n Q oo C 14 H 10 9 _ c^H^oH^co 8 \ O = 322 (SCHIFF), but containing a portion of glucoside of digallic acid. Gallotannic Acid. The TANNIC ACID of the pharmacopoeias and of commerce. Gallotannin is identified as a tannin by its sensible properties (#, J), its reactions with gelatin, alkaloids, iron salts, and perman- ganate (d) ; identified as gallotannin by its fermentation pro- duct (c and p. 467), its product by heat (#), its color with ircn salts, with molybdate, and the total bearing of its qualitative tests (d) ; estimated by the method of Lowenthal, Gerland, or Wagner (pp. 468-73) ; separated from metallic compounds, iron inks, and the fruit acids, by acetic ether (. Dextrotartaric acid is found in commerce in large, hard, fragmentary, permanent, water- white crystals, or in an opaque- white, fine powder. The crystals, H 2 C 4 H 4 O 6 , are mo- noclinic, oblique rhombic prisms, hemihedral, the most perfect ones showing two corners truncated on the same side while the two opposite corners are not cut off They are pyro-electric, pinning in the dark, after friction. The specific gravity is 1.764. The dry acid melts at 135 C., forming a clear liquid, which at 170 C. is converted into metatartaric acid, deliquescent and un- 1 For directions for removal of stains a^d spots of many kinds see N?w Jit-moli?*, March, 1882, u. 74; Am. Jour. Phar., Dec., 1880, 52, 632; New irs, .Ian., 1883, 12, 24. 486 TARTARIC ACID. crystallizable, and at about 200 C. forms anhydrides, some of which do not dissolve readily in water. At a higher tempera- ture the mass blackens and evolves vapors with a strong odor of burnt sugar or caramel. Concentrated sulphuric acid dissolves dry tartaric acid in the cold without color, the mixture charring when warmed. c. Tartaric acid is soluble in less than its weight of cold water, in about three parts of alcohol (of absolute alcohol, four parts BOURGOIN, 1878), in 250 parts of absolute ether, 1 soluble in methyl alcohol and in amyl alcohol, insoluble in chloroform and in benzene. The water solution rotates the plane of polar- ized light to the right. Decomposition soon occurs in water solution, with a fungoid growth containing nitrogen. The normal tartrates of potassium, sodium, and ammonium, and the acid tartrate of sodium, are freely soluble in water ; the acid tartrates of potassium and ammonium are sparingly soluble in water; the normal tartrates of non-alkali metals are insoluble or only slightly soluble in water, but mostly dissolve in solution of tartaric acid. Tartrates are insoluble in absolute alcohol. Aqueous alkalies dissolve most of the tartrates (those of mercury, silver, and bismuth being excepted), generally by formation of soluble double tartrates, such as K 6 Fe 2 (C 4 H 4 O 6 ) 6 , a scale prepa- ration of the pharmacopoeia. For this reason tartaric acid pre- vents the precipitation of salts of iron and many other heavy metals by alkalies. Alkali normal tartrates also hinder the pre- cipitation of lead and barium sulphates, manganese sulphide, and ferrous ferricyanide. 3 Hydrochloric, nitric, and sulphuric acids transpose tartrates. d. Lime solution, added to free tartaric acid solution until the reaction is alkaline, gives a precipitate without warming (distinction from citric acid, which precipitates only when heat- ed). With a neutral tartrate the precipitation ^ is obtained by adding much of the lime solution or by boiling^ Calcium chloride solution is precipitated, not by free tartaric acid, but by neutral tartrates, in solutions not very dilute, and when neither the tartrate nor the lime salt is in large excess. The precipitate, calcium tartrate (see p. 498), when ireely formed is voluminous and amorphous, and dissolves in about 1000 parts of cold water, in an excess either of the tartrate or the calcium Bait, in acetic acid (distinction from oxalate), and in ammonium 1 J. NESSLER. 1*879: Zeitsch. anal Chemie, 18, 230. 2 SpiLLER. 1858: Jour. Chem. Soc., 10, 110. TARTARIC ACID. 487 chloride. On standing, or in dilute solutions at its first forma- tion as a delayed precipitate, it assumes a crystalline form, much less easily seen than the amorphous form, and less easily dis- solved by any of the solvents above named, hardly soluble by acetic acid. The calcium tartrate precipitate is soluble in cold strong potassa solution (distinction and partial separation from citrate or oxalate) ; the precipitate reappearing when the liquid is heated, and again dissolving as it cools. This reaction is best obtained with the washed calcium tartrate precipitate ; an ^ ex- cess of calcium chloride in the mixture interferes. Calcium sulphate solution is not precipitated by free tartaric acid (diffe- rence from oxalic acid), but gradually gives a slight precipitate with tartrates (difference from citrates). Solution of potassium acetate, or citrate, precipitates free tartaric acid, as potassium hydrogen tartrate, KHC 4 H 4 O 6 . The precipitate forms slowly, in trimetric crystals, which subside, the formation being favored by stirring with a glass rod. The precipitate dissolves in alkalies by formation of normal tartrates. In this test a neutral or alkaline liquid is to be strongly acidu- lated with acetic acid, which does not at all dissolve the precipi- tate. If a free mineral acid be present, only so much the more reagent potassium acetate is to be added. The precipitate is soluble in about 180 parts water at common temperatures and in 15 parts boiling water, insoluble in alcohol, and not apprecia- bly soluble in fifty per cent, alcohol. Two volumes of ordinary alcohol may be added to one volume of the aqueous solution, with strong acetic acidulation, to hold other salts in solution. This precipitate is a separation from citric, malic, and oxalic acids, and from salts of many inorganic acids as well. In the latter case care must be taken that the alcohol does not throw down inorganic salts of potassium. Further, see p. 490. Tartaric acid is distinguished from citric acid, in crystal, and the former is detected in a crystalline mixture of the two acids, as follows : * A solution of 4 grains of dried potassium hydrate in 60 cubic centimeters of water and 30 cubic centimeters of 90 per cent, alcohol is poured upon a glass plate or beaker-bottom to the depth of about 0.6 centimeter (one-fourth inch). Crystals of the acid under examination are placed, in regular order, three to five centimeters (one to two inches) apart, in this liquid, and left without agitation for two or three hours. The citric acid crystal dissolves slowly but completely and without losing its 1 Hager's "Untersuchungen," ii. 103. 488 TARTARIC ACID. transparency. The tartaric acid crystal (or the crystal contain- ing tartaric acid) becomes, in a few minutes, opaque white (in a greater or less degree), and continues for hours and days slowly to disintegrate without dissolving and with gradual projection of spicate crystals, fibrous and opaque. Solution of lead acetate precipitates free tartaric acid or tartrates, as white normal tartrate of lead, very slightly soluble in water, insoluble in alcohol, but slightly soluble in acetic acid, readily soluble in tartaric acid, in ammonia, and in tartrate of ammonium solution, and freely soluble in ammoniacal solution of tartrate of ammonium (distinction from Malate), somewhat soluble in chloride of ammonium. A color test is made, after removal of heavy metals or oxid- izing agents, by adding, to the acid or its alkali salt, a little fer- rous sulphate solution, then a little hydrogen peroxide, or chlo- rinated soda solution, or acidulated permanganate solution (the first of these three being the best) avoiding an excess of the oxidizing agent lastly an excess of potassium or sodium hydrate solution, when a fine violet color gives evidence of the presence of tartaric acid. 1 Solution of silver nitrate precipitates solutions of normal tartrates (not free tartaric acid) as white argentic tartrate, soluble in ammonia and in nitric acid. On boiling the precipitate turns black, by reduction of silver, some portion of which usually deposits as a mirror-coating on the glass. The reduction to the specular metallic form may be obtained, from even slight quan- tities of tartaric acid, as follows : Acidulate the solution with nitric acid, add some excess of silver nitrate solution, filter out any precipitate (not tartrate), and add very dilute ammonia-water to slight alkaline reaction. If a precipitate of silver tartrate appears, add. the ammonia till it is nearly all redissolved, filter, heat to near the boiling point for a minute, and set aside in a warm place. (Citric acid does not effect this reduction, or only on long boiling.) Free tartaric acid does not reduce silver from the nitrate. Permanganate of potassium solution is reduced very slowly by free tartaric acid, but quickly by alkaline solution of tar- trates, with precipitation of manganese dioxide, brown (a dis- tinction from Citrates, which reduce permanganate but very slowly, and then form green solution of manganate, more than precipitate of dioxide). Dichromate of potassium solution is 1 FEXTON, 1881: Chem. News, 43, 110; Jour. Chem. Soc., 40, 655; New Remedies, 10, 147. TARTARIC ACID. 489 readily reduced by tartaric acid, with appearance of a green color and slight effervescence. For use of this test in distinction from malic, citric, and succinic acids, see under Malic acid, at c. In the detection of tartaric acid in Citric acid of commerce, CAILLETET l directs to take 10 c.c. of saturated dichromate solu- tion, add 1 gram of the acid to be tested, and stir, not warming. After ten minutes' standing he found pure citric acid to remain orange -colored ; that with 1 per cent, tartaric acid, coffee-col- ored ; with 5 per cent, tartaric acid, black-brown. Among the products of the oxidation of tartaric acid by permanganate and chromate are formic acid, carbon dioxide, and water. Cop- per sulphate with potassium hydrate is not reduced -by tartaric acid. Gold chloride solution is reduced only in solution made alkaline with potassium hydrate, when a black precipitate of aurous chloride is formed. e. Tartaric acid may be separated from tartrates by adding its equivalent quantity of sulphuric acid and extracting with alcohol (in which most sulphates are insoluble). Free tartaric acid may be taken out of water solutions by agitation with amyl alcohol, which, after standing, is decanted. From the other fruit acids (citric, malic, oxalic), and most inorganic acids, it is best separated by its precipitation as bitartrate (j), also approxi- mately separated by its calcium reactions (, and in detailed scheme under Malic acid, d). From tannin and gallic acid as noted under Gallotannin, p. 477. From acids whose lead salts are soluble in water, by treatment with lead acetate, followed by hydrogen sulphide, etc. f. Quantitative. Free tartaric acid, if unmixed with other acids or salts which neutralize alkalies, may be estimated volume- trically by standard alkali solutions, the point of saturation in normal tartrate being sharply defined by the tint of litmus or by phenol-phthalein. Weighing 0.750 gram, the number of c.c. of decinormal alkali solution required equals the number per cent, of the acid. Each c.c. of normal alkali neutralizes 0.075 gram of acid. The acid tartrate of potassium, obtained by precipitation, as directed below, may also be exactly estimated by acidimetry, when each c.c. of normal alkali solution required indicates 0.150 gram of tartaric acid. Another way, properly used in some cases but having no advantage if the acid tartrate be pure, is to gradu- ally ignite the dried precipitate of acid tartrate, at a low red heat, 1 Jahresb. d. Phar., 1877, 316; from Jour, de Phar. et de Chim. [4] 25, 573; Zeitsch. anal. Chem., 17, 499. 490 TA&TARIC ACID. till vapors no longer rise, cool and treat the charred mass (con- taining all the potassium as carbonate) thoroughly with water and a slight excess of volumetric acid from the burette, boil, and filter, and wash well, and titrate back with volumetric alkali. Each c.c. of normal acid, after deduction of the number of c.c. of corresponding alkali solution used, indicates (the same as when measuring the acid precipitate with alkali) 0.150 gram of tartaric acid in the bitartrate. Much care is needed to avoid loss during ignition. Tartaric acid is capable of estimation volumetrically by oxidiz- ing agents. A method with use of dicbromate for this purpose has been proposed (compare Citric Acid, c) . The use of permanga- nate for titration of tartaric acid in metallic salts has been re- ported by F. W. CLARKE, 1881. 1 The gravimetric determination most generally applicable is that by precipitation as potassium hydrogen tartrate, though this precipitate is more easily and surely treated volumetrically. The reagent is the acetate of potassium, or, if iron or alumi- num be present, citrate of potassium (WARINGTON); and if the tartaric acid is in neutral salts, acetic add should be added with the acetate (or citric acid with the citrate) to a decided acid reaction, and enough to fully prevent the formation of the freely soluble normal tartrate. In simple mixtures the acetate is better than the citrate, and excess of either is to be avoided. By use of alcohol the precipitate may be made complete, and may be washed without loss. The moist precipitate, just washed volume- trically clean, may be titrated (either with the filter or transfer- red) with standard alkali, as directed above, or, after washing gravimetrically clean and drying at 100 C., the precipitate may be weighed. KHC 4 H. 4 O 6 : H 2 C 4 H 4 O 6 ::1 : 0.797. The strength of alcohol, in the precipitation and in the washing, should be at least 50$ by weight, unless some other agent is depended upon to diminish the solubility of the precipitate. If no interference is apprehended the strength may be 60 to 65$. 2 If sulphates 1 Am. Ghem. Jour., 3, 201. 2 The author has found the precipitate to be washed continuously with 50 per cent, alcohol without weighable loss FLEISCHER, 1870: Zeit'sch. anal. Chem., 9, 331; Am. Chem., I, 352. using the precipitate for the determination of potassium, finds it insoluble in 50 per cent, alcohol. (If sodium be present, to avoid its precipitation he directs to add ammonium chloride.) CASSAMAJOR, 1876: Am. Chem., 7. 84, finds that alcohol of about 60 percent, is needed to preserve the precipitate from waste. Strong acidulation with acetic acid has no solvent effect on the precipitate. WARINGTON found tartaric acid to have no solvent power, citric acid a slight solvent power, and hydrochloric acid much solvent power, when applied, in water, to the precipitate. TARTARIC ACID. ,491 are present they are liable to be precipitated by the alcohol, and will interfere with the gravimetric treatment of the precipitate. A sulphate of aluminium, or iron, or any other salt that will neutralize an alkali, will interfere likewise with the volumetric treatment ; but a sulphate of calcium, or any salt that does not neutralize an alkali, may be permitted to go into the precipitate if this is to be volumetrically determined. Further, as ascertained by WARINGTON and applied in his methods, given below, the precipitate is but little soluble in chloride of potassium solu- tion. For determination of tartaric acid in complex Liquors of Citric and Tartaric Acids, occurring in the manufacture of these acids, WAKINGTON 1 directs as follows : A quantity of the liquor containing from 2 to 4: 'grams of tartaric acid, and of 30 to 40 c.c. in volume, is treated with citric acid unless free sul- phuric acid is present, then treated with a saturated solution of normal potassium citrate, added in measured .quantity drop by drop with constant stirring. If free sulphuric acid is present no precipitate appears until this is satisfied, when the streaks of bitartrate form on the sides of the vessel. An excess of reagent is avoided, and 4 c.c. are enough for the maximum of 4 grams of tartaric acid. If there is a great deal of sulphuric acid, a fine precipitate of potassium sulphate may appear before the precipi- tation of bitartrate. The occurrence of a gelatinous precipitate shows that not enough citric acid was added, and it is better to begin again. After standing twelve hours the precipitate is col- lected on a small filter, preferably a vacuum filter, and washed with two or three small portions of a five per cent, solution of potassium chloride, then with portions of alcohol, successively of 50$, 70$, and 80$ to 90$ strength, till the washings are no longer acid to litmus. The gradual increase of strength of alco- hol, and the previous use of aqueous solution of potassium chlo- ride, are to prevent the precipitation of salts other than the bi- tartrate, such as the gelatinous phosphates of aluminium and iron, which may clog the filter, and some of which may interfere with the titration. The filter and contents are now transferred to a beaker, and the bitartrate estimated volumetrically with standard alkali. Warington also gives a method of washing the precipitate only with a saturated solution of bitartrate of potas- 1 Pages 977-980 of the important report on the analytical work of Citric and Tartaric Acid Manufacture, 1875: Jour. Chem. Soc., 28, 925-994. Con- tinued, on Determination of Tartaric Acid in Lpes. by GROSJKAN, 1879: Jour. Chem. Sue., 35, 341 ; 1883: 43, 334; Jour. Soc. Chem.' Indus , 2, 338. 492 TARTARIC ACID. slum, " till the acidity of the drain-water is no greater than the acidity of the wash-water," as found volumetrically. The drained filter may be weighed, dried, and weighed again, to iiiid the amount of bitartrate solution in the drained filter, so that a cor- rection can be made for the bitartrate retained in the wash- liquid. If there be potassium sulphate in the precipitate, it will interfere with use of this wash-liquid by causing a precipi- tation of bitartrate from its solution. The methods of estimation of the total tartaric acid in tartar, argol, and lees, were summarized by WAKINGTON in 1$75 l es- sentially as follows : A. The tartaric acid of the acid tartrate of potassium is found by acidimetry, or calculated from determination of the potassium with platinum salt after calcining. The calcium is determined gravimetrically after calcining, and from this is cal- culated the tartaric acid of the neutral calcium tartrate. B. The calcined tartar is exhausted with water, the dissolved potassium carbonate and the undissolved calcium carbonate are separately estimated with standard acid and alkali, and the tar- taric acid is calculated from both the acid tartrate of potassium and the normal tartrate of calcium. C. The tartaric acid of bitartrate is found by acidimetry. Another portion is calcined and the total alkali (including lime) found by alkalimetry. The number of c.c. of alkali for the bitartrate, subtracted from the number of c.c. of corre- sponding acid solution for the ash, leaves the number of c.c. of this acid required for the lime, that is, the bases in normal tartrates. D. The whole of the tartaric acid is converted into normal tartrates by exact neutralization with soda, the whole evaporated to^ dryness, calcined, the neutralizing power of the ash deter- mined, and the total tartaric acid calculated therefrom. It is an estimation of the carbonates formed in calcining neutral salts. With a pure tartar (having only the bitartrate, the calcium tartrate, color, and sand) any one of these methods will give nearly correct results of total tartaric acid. Methods A, B, and give the tartaric acid in the bitartrate, as well as the total. Calcium carbonate in the tartar interferes with methods A and B, the carbonate, if not crystalline, being acted upon by the bitar- trate in obtaining a solution in A. Calcium sulphate also causes 1 Jour. Chem. Soc., 28, 959. TARTARIC ACID. 493 error in methods A and B. But methods C and D are trust- worthy in presence of carbonates and sulphates (unless sulphides are formed by ignition, as they will be if nitrogenous organic matter is present with sulphates). If crystallized carbonate of calcium is present, in .method C it must be dissolved with the tartar by adding a measured quantity of standard hydrochloric acid, before the acidirnetry, afterward deducting the standard alkali needed to neutralize the hydrochloric acid. In method D, any calcium carbonate must be dissolved by first adding enough hydrochloric acid. In any of the four methods the pre- sence of organic acids other than tartaric, such as malic acid, or acid products of a change in tartaric acid, introduces error. Of the four methods, Warington gives preference to method C, though in presence of carbonates it does not show exactly how much of the total tartaric acid is in the bitartrate. If there be free tartaric acid there must be more than a corresponding quan- tity of normal tartrate, when this method is to be used. The details of method C are given as follows 1 : Five grams of the powdered tartar are heated with a little water, long enough to dissolve any calcium carbonate, and, if presence of crystallized carbonate be apprehended, 5 c.c. of standard hydrochloric acid are added and a covered beaker used. Standard alkali is then added to the extent of about three-fourths of that required for a good tartar and for the hydrochloric acid, and the liquid is brought to boiling. When cold the titration is finished. From the amount of alkali (minus that required by hydrochloric acid) the tartaric acid in the bitartrate is stated (p. 489). Two grams of the powdered tartar are weighed into a platinum crucible with a well-fitting lid ; the crucible is placed over an argand burner ; heat is applied very gently to dry the mass, and then more strongly, till inflammable gases cease to be evolved, keeping the heat at low redness or below. The black ash is next removed with water to a beaker, and some excess 20 c.c. if the tartar is a good one of normal acid solution is added from the burette, rinsing the crucible with the acid and then with water. After boiling and filtering the excess of acid is titrated with standard alkali, bringing the filter and its contents into the beaker at the last. From the neutralizing power of a gram of burnt tartar is subtracted the acidity of a gram of unburnt tartar, both expressed in c.c. of standard alkali, and the difference is the neutralizing power of the bases existing as neutral tartrates, then to be calculated into tartaric acid. One c.c. of normal 1 Jour. Chem. Soc., 28, 961. 494 TARTARIC ACID. alkali is the equivalent of O.OT5 gram of tartaric acid in normal tartrate. Warington's method of direct estimation of total tartaric acid of argols and lees, known as " the oxalate method," is se- cure against the errors arising from presence of carbonates and sulphates, the formation of sulphides, and action of vegeta- ble acids not tartaric. It provides a removal of the calcium by precipitation with potassium oxalate, a precipitation of all the tartaric acid as potassium bitartrate, and volumetric esti- mation of the latter. 1 This method, supplemented by a sim- ple acidimetry to show nearly the quantity of acid in bitar- trate, may be adapted to various troublesome analyses of adul- terated cream of tartar. A quantity of the material, in pow- der, sufficient to contain about 2 grams of tartaric acid, is placed in a small beaker, covered with water, and heated on the water- bath till thoroughly softened. Sufficient solution of potassium oxalate (of about 25$ strength) to unite with all the calcium and give an excess of about 1J gram of oxalate is then added, and the heat maintained, with frequent stirring, for half an hour. The solution, if strongly acid, as it usually will be, is now nearly neutralized by carefully adding solution of soda by drops, the reaction being left distinctly acid, and digestion on the water- bath continued half an hour. The volume of liquid is now made about 30 c.c., and the whole filtered (while hot) with a vacuum filter. Mr. Grosjean uses Cassamajor's filter, 2 in an or- dinary funnel, and very little vacuum. The residue is washed ten times, each with 2 or 3 c.c. of water, and the washings sepa- rately concentrated to bring the whole filtered liquid to 50 c.c. Five grains of potassium chloride are now added and dissolved, and the solution treated, while cold, with a quantity of citric acid equal to, or a little greater than, the quantity of tartaric acid to be found. The liquid is stirred continuously for ten minutes and set aside half an hour, then collected on a vacuum filter and washed twice with a five per cent, solution of potas- 8 WARINGTON, ibid., p. 973. GROSJEAN, 1879: 35, 341: " This method, with individual variations, is, I believe, now exclusively employed in fixing the value of lees and inferior argol sold in the London market." A similar plan, of simpler execution, with use of carbonate of potassium (instead of oxalate) to precipitate calcium and bring all the tartaric acid into solution as normal salt, and with acetic acid and alcohol as precipitants, is given by GOLDENBERG and others, 1884 : Zeitsch. anal. Chem., 22, 270; Chem. A r eivs, 48; New Rem., 12, 242. The precipitation by potassium carbonate has been employed gravimet- rically for the calcium. * 1875: Am. Chem., 5, 438; Chem. News, 22, 45. TARTARIC ACID. 495 slum chloride, then twice with fifty per cent, alcohol, and lastly with strong alcohol till the washings are no longer acid to lit- mus. The whole washing may be done with a five per cent, solution of potassium chloride carefully saturated with potassium bitartrate, continued till the washings neutralize no more stand- ard alkali than the wash-liquid, in the end making a correction for the acid in the liquid remaining in the filter. The pre- cipitate and filter, transferred to a beaker, are titrated with standard alkali (p. 489). If by inattention too much reagent oxa- late of potassium have been used, acid oxalate of potassium may be crystallized in the precipitate. In the analysis of good tartar by this method the filtering of 'the oxalate precipitate may be omitted, and the citric acid added to the cold neutralized mix- ture. In this case the oxalate of calcium, vegetable matter, and sand, in the bitartrate precipitate, do not affect the titration. In estimating tartaric acid in Fruit Juices, as a general method providing for the other fruit acids, FLEISCHER 1 directs as follows : Filter clear, if necessary by the addition of alcohol, and washing on the filter with alcohol or hot water. The liquid is fully precipitated with lead acetate solution the precipitate drained on the filter and washed with aqueous alcohol, and then treated thoroughly with excess of ammonium hydrate (free from carbonate) and filtered. The residue contains lead salts of any phosphoric, sulphuric, and oxalic acids of the fruit ; while tartaric, citric, and malic acids are in the filtrate. The latter is treated with some excess of ammonium sulphide, then acidulated with acetic acid, and filtered. This filtrate, boiled to expel hydrogen sulphide, is treated with potassium acetate and alcohol, as above directed, for estimation of the tartaric acid by acidimetry of the precipitate. The filtrate contains the citric and malic acids, which are now precipitated by addition of calcium chloride, am- monium hydrate, and a little alcohol. The precipitate of citrate and malate may be freed from malate by washing it with boiling solution of calcium hydrate. The citrate may be dissolved in acetic acid, and precipitated by lead acetate, to weigh as lead citrate. f- Tartaric acid, in pure water solution, has percentages corresponding to specific gravities, as follows : s 1 1874: Zeitsch. anal. Chem., 13, 328, in full from Archiv d. Pharm. [3] 5, 97; Amer. Chem., 6, 154; abstracted in Jour, Chem. Soc., 27, 1181, and in Pro. Am. Phar. Assoc.., 1875, 380. See also A. H. ALLEN: Phar. Jour. Trans. [3] 6, 6; Jahresb.d. Chemie, 1875, 969. 2 ScHiFF. See also GERLACH: Zeitsch. an. Chem., yiii. (1869) 295. 496 TARTARIC ACID. 1.0167 sp. gr. at 15 C 3.67 per cent. 1.0337 " " " 7.33 " 1.0511 " " 11.00 " 1.0690 " " " 1466 " 1.1069 " " " 22.00 " 1.1654 " " 33.00 2 Dr. B. G. LOVE, acting for the New York State Board of Health, in 1882 (Sanitary Engineer, March 30; The Analyst, 7, 142) found, of 84 baking-pow- ders upon sale, 49 were cream of tartar powders, 3 were tartaric acid powders, 20 were alum powders, 3 were acid phosphate powders, 8 contained both cream of tartar and alum, and 1 had alum with acid phosphate. Flour or starch was found in all but 11. Ammonia was found in 35. [The alum reported in 29 of them was doubtless ammonia alum.] Eight were reported adulterated six with terra alba, one with tartrate of lime (in the tartar), and one with insoluble calcium phosphate. BAKING-POWDERS. 501 has been dispute as to the injurious effect of alum baking-pow- ders, but, at all events, they are seldom if ever sold to the public with any statement or admission that they contain alum. The proportion of carbon dioxide extricated on boiling a baking-powder with water is termed its " strength," and is stated in percentage of weight, or in cubic inches (at 60 F., 30 in. bar.) from an avoirdupois ounce. In the case of a cream of tartar powder we have : NaHC0 3 + KHC 4 H 4 O 6 = KNa C 4 H 4 6 + CO 2 + H 2 O 84 +188 = 272 44 +69.12$ = 100.00$ 16.17$ At 60 F. and 30 inches pressure 34.18 grains of carbon dioxide measure 100 cubic inches ; therefore 16.17 grains measure 34.18 cubic inches. That is to say, 100 grains, of a mixture 30.88$ ab- solute bicarbonate and 69.12$ absolute bitartrate, will furnish 16.17 grains or 34.18 cubic inches of the gas. And 1 av. oz. of the same chemically pure mixture will "furnish 149.54 cubic inches of the gas. If we have a baking-powder holding, for ex- ample, 84$ of the equivalent soda and tartar, then no more than 84$ of 149.54 cubic inches of gas can be obtained from one av. ounce. Less than the theoretic yield of gas may be obtained (1st) because reaction of the tartar upon the "soda may have trans- pired in the mixture (not fully dry), (2d) because" of deficient quality of the soda, or of the tartar, or of both, and (3d) because of wrong proportions of tartar to soda. With the proportions of filling before mentioned, cream of tartar baking-powders, in moderately dry air, will not appreciably lose carbon dioxide. Powders made with tartaric acid lose gas more readily, and the same has been stated of the acid phosphate powders. 1 The examination of baking -powders should begin with a qualitative analysis. In answer to special questions, tests may be briefly made for sulphates, ammonia, aluminium, residue in- soluble in boiling water (besides gelatinized starch), and calcium in watery solution, as well as in acid solution of any residue not dissolved by water. Phosphate may be tested for in acid solu- tion by moiybdate. Free tartaric acid would be found in a fil- tered alcoholic solution. The reaction to test-paper after boiling thoroughly in water is of first importance. This is neutral in 1 In 1881 Dr. E. G. LOVE reported the yield of gas in cubic content from sixteen different brands of American Baking-Powders (The Analyst, 6, 65). From one ounce the highest yield was 127.4 cubic inches of gas, and the lowest was 75.0 cultic inches, except one (old) which was 82.7 cubic inches. Ten fur- nished over 100, and four over 120, cubic inches of gas. 502 TARTARIC ACID. well made powders: it is seldom found to be acid, but. is some- times found to be alkaline. In the estimation of the carbon dioxide, only that quantity of gas which is liberated by water, with warming at the end to boiling point, and without adding an acid, can be counted as " strength." However, if an alkaline reaction have not been found after boiling with water, the use of an acid to liberate 'the gas will introduce no inaccuracy in finding the " strength." The writer prefers to estimate the carbon dioxide by the method of increase of weight of absorption tubes, using water without acid and with gentle heat finally to boiling, to liberate just the gas counted as strength. Methods by diminution of weight due to escape of the dried gas seldom give trustworthy results, at least in the writer's observation. If a Scheibler's apparatus for measur- ing the volume of the gas be at hand, it may be used, with addi- tion of hydrochloric acid in the usual way ; but if it be a powder showing an alkaline reaction after boiling with water, a correction must be made, from results of alkalimetry after boiling with water, for statement of the " strength." With a true cream of tartar baking-powder (free from alum) a most serviceable valuation can be made by a simple alkalimetry of the ash (A), together with alkalimetry of the liquid obtained by boiling the baking-powder with water (JB) in case this liquid be alkaline, or acidimetry of the same (c7) in case it be found acidulous. Using decinormal volumetric solutions of acid and alkali, In A, 1 c.c. of acid = 0.0136 gm. soda tartar (Na HC0 3 + KHC 4 H 4 O 6 ) In B, 1 c.c. of acid = 0.0084 gm. excess of soda (NaHCO 3 ) In tf, 1 c.c. alkali = 0.0188 gm. excess of tartar (KHC 4 H 4 O 6 ) If the powder be found to have an excess of alkali, to estimate this weigh 0.840 gram, boil with water, add from the burette some excess of decinormal solution of acid, boil again, and bring back to the neutral point by adding decinormal alkali from a burette. The number of c.c. (B) of decinormal acid, beyond that taken to neutralize the decinormal alkali used, equals the number per cent, of excess of sodium bicarbonate (that is, the number of parts of such excess in 100 parts of baking-powder). If the baking-powder have an excess of acid, weigh 1.880 gram, boil, and add from the burette decinormal solution of alkali to neutralize. Then (as above) c.c. (C) = parts excess of potas- sium bitartrate in 100 parts baking-powder. Whether the boiled liquid have been found alkaline, acid, or neutral, for the BA KING-PO WDERS. 503 ash weigh 1.360 gram of the baking-powder, heat it in a covered capsule very gradually, so as not to permit the puffy mass to reach the cover, at last continuing a red heat for fifteen or twenty minutes after the vapors have ceased to rise. Cool the capsule, boil it (cover and all) with a little water, in a beaker, gently rubbing up the black ash with a glass rod. If no separa- tion of calcium of the tartar is to be undertaken, the decinormal acid may now be added at once, in excess, the mixture boiled, and (being acid after boiling) filtered and washed till the wash- ings do not change blue litmus-paper. The filtrate and washings are titrated back to the neutral point with decinormal alkali. If the powder have been found neutral after boiling at the begin- ning, the c.c. of decinormal acid, minus the c.c. of decinor- mal alkali, = the parts of absolute equivalent-soda-tartar (NaHCO 3 + KIIC 4 H 4 O 6 ) in 100 parts of the baking-powder. If the powder have shown an excess of alkali, then f f ( -^ 3 3 6 - = 161.9$) of the number of c.c. B, found as above, is to be deduct- ed from the number of c.c. required for the ash. If the powder have shown an excess of acid, deduct ff ( = iff = 72.34$) of the number of c.c. C (decinormal alkali) from the number of c.c. of decinormal acid used for the ash. In each of these cases the remainder = parts of equivalent soda-tartar in 100 parts of baking-powder. Then the per cent, of sodium bicarbonate in the baking-powder is 30.88$ (p. 501) of the per cent, of equivalent- soda-tartar, plus the per cent, of excess of " soda," if any. And the total per cent, of potassium bitartrate is 69.12$ of the per cent, of soda tartar, -f- any per cent, of excess of "tartar" found. If it be desirable from the qualitative indications to esti- mate the calcium tartrate in the alkalimetry of the ash, the black ash from the capsule must be exhausted and washed with boiling water until the washings no longer show an alkaline reaction to litmus or to phenol-phthalein when the total filtrate is ti- trated, as above directed. The residue, filter, capsule, and all, is now digested, cold, with standard hydrochloric acid, or, if there be not a laroje quantity of calcium, digested w r arm with standard sulphuric acid and sufficient water, filtered, washed (compare on p. 499), and the filtrate titrated back for alkalimetry of the cal- cium carbonate, referred to tartrate. 1 c.c. of decinormal solu- tion of acid, neutralized by the washed ash, indicates 0.0130 gram of crystallized (or 0.0094 gram of anhydrous) calcium tartrate (p. 498). The quantity of calcium tartrate found is to be added to the total quantity of potassium bitartrate found ($ of latter ~ 100 X 1.36), the sum being the quantity of cream of tartar (not 504 TEAS OF COMMERCE. lime-free) used in the 1.36 grain of baking-powder. Statements are then made of the percentage of cream of tartar in the baking- powder, and of the percentage of calcium tartrate in the cream of tartar. These percentages may be calculated, directly from numbers of c.c. found, as follows : 1.36 gram baking-powder having been calcined, 95.6$ of the c.c. for CaCO 3 (m) -\- % of total KHC^H^Og previously found = % (ri) cream of tartar (not lime-free) in the baking-powder. And m -=- n = % of crystal- lized calcium tartrate in the cream of tartar used. The calcium tartrate may be determined gravimetrically, as given on page 500, or on page 499, the precipitate of carbonate being ignited to re- move starch, if necessary. For estimation of constituents of baking-powders, used also in adulteration of cream of tartar, see pp. 498 to 500. TEAS OF COMMERCE. The prepared leaf of the Thea, native to the Himalayas and Assam, long cultivated in China and Japan, and now cultivated in India. The kinds of tea known in commerce are distinguished in the first place by the age of the leaf employed. Thus, the youngest leaf is found in " Howery pekoe".; the next in age, successively in "orange pekoe," u pekoe," " souchong," and " bohea," Without distinc- tion of the age of the leaf, " green teas " differ from " black teas " according to the mode of preparation. The treatment of the fresh tea leaf in manufacture of tea is always an elaborate operation, and includes exposure to a roasting temperature. For black teas the leaves are withered a little, rolled to liberate the juices, left in balls for the proper extent of fermentation, then sun-dried and subjected to a careful firing in a furnace. For green teas the fresh leaves are first withered in hot pans, then rolled to free the juices, slightly roasted in the pans, sweated in bags, and returned to the pans for a final slow roasting, with stirring, for eight or nine hours, beginning at the temperature of 160 F., and falling to 120 F. at the close. The outline of operations here given is one of modern simplification, somewhat as conducted by planters in India, and considerably less elabo- rate than the methods of the Chinese. In black teas the greater extent of fermentation and the sharper " firing " appear to re- duce the quantity of tannin, and certainly leave the tannin and the other extractive matters in a less readily soluble condition. Teas contain essential oil, which is undoubtedly affected by the curing process. An extended investigation of teas imported into the United States was made in 1884 by Mr. Geisler, of New York, who is TEAS OF COMMERCE. 505 engaged in the analytical chemistry of foods, and his report is of *great scientific and practical value. The tabular summaries of the report, and Mr. Geisler's 1 principal conclusions bearing upon the methods of infusion in the preparation of tea as a bev- erage, are presented on pages 506 to 508. In Table L, showing the principal constituents of commer- cial teas, it will be noticed that there is no uniform relation existing between the composition of teas in general and the value of the same. Teas of the same kind from the same district would no doubt show a more uniform relation as to composition and price. The percentage of extract, determined by half-hour boiling of the tea leaf in one hundred parts of distilled water, bears, at least in Oolong and Congou teas, a more uniform relation to the price than the other constituents determined, although the total ex- tract obtained by exhausting the leaf is very irregular. This is quite in accord with a fact "which dealers in tea are aware of namely, that the finer and more valuable qualities of tea of any line consist of young and tender leaves, while the medium and poorer grades contain older and tougher leaves. The younger a leaf is the more tender and succulent will it be, and it therefore follows that it gives up its extractive matter more readily to water, which is all the more important in the customary house- hold method, where boiling water is poured upon the leaves and allowed to draw for only a given length of time. The percentages of theine, tannin, and soluble ash are too ir- regular to show any relation between their per cents, and the price of the tea. It appears from these analyses, however, that the finer the quality of the tea the more theine, soluble ash, and extractive matter will it contain ; still, the same is not uniformly true. The percentages of extract (total) and insoluble leaf are still more irregular when compared with the price of the tea. The results in Table III. are of greater interest, since they show the principal constituents of tea which are actually taken up by water in the ordinary preparation of tea as a beverage. In order that the results would be strictly comparable, the in- fusions of the different teas were all prepared under precisely 1 JOSEPH F. GEISLER, Ph.C., chemist to the New York Mercantile Ex- change. 1884: A m. Grocer, Oct. 23. The discussion of the results following (pp. 510, 511) is taken wholly from Mr. Geisler's report. "Although the che- mical composition of tea has frequently been made the subject of analytical inquiries with a view of ascertaining the relation existing between the chemical composition. and the commercial value of tea, the amount of work previously done relative to teas of this market is very meagre. " 506 TEAS OF COMMERCE. -joy uouituoo poof) mos -?0y UOUIUIOO pOOf) Smuoj? 'noduoQ Smttojf 'noduoQ ' noBuoQ noQuoQ o c io *o o* cc * * =* ~ ~ nod 'noSuoj pdMg-uvj untiio f ).(iof) tiq^ pwC uoiutuoj -unf) aunfiojp u't l f pun/toff i> co ot o e eo S S eo' i-i 8 - . So o fe s a c l> W rn OJ fe o o -I o O O "' 11 ; I Wi i 1 a hfl on jj =i| 2^1 _ -I* 3 MO S3 'gggS^- s * o*- 2 gUSfS ifSgteS g-SgSo* llili ^sl=4 ",^5 e d ne, t cic a obt So A thei bohc thus TEAS OF COMMERCE. 507 TH CO TO TO" TO g duoioo vsmuMtf MU9dns os * i. o 2 to' Suopo Kouiy utmpyjv lO ^ lO T^ <* 10 TO 1-1 OS /Unuy wmp9jj[ 'duopo uimpm poof) 3^3 TH 10 M TO" 52 buopo nsouuoj? uouzdng 8 3 g g ^ S? Buopo o? S Gitojoo O TO S 5 ' S JS S CO O? TO d oi TO nsouuog duopo )g TO O 00 OS CO ffX *J r*^ (^ S S B 9 'V9j J uvipuj 'V9J, umpuj 'V9j; umpui g 'vw umpui umpuf 53 S i-J 10' g s g TO T-( 10 gi S 883 53 fe ^ S S S 8 10' TO CO OS CO id M TO lO O TO SSI i s s 10 O! TO I 1 i 1 PH S l c 3 g ; i S 1 g I I I 4 g < ill -2 g 5 5o8 TEAS OF COMMERCE. I | />- CO TH CO ppy "jpvuj ysy * OS . v w si TH ci oo 257-ico^ ooi-co25 co i-i w oi co' T-I si si si -r-i si si muuvj; 00 CO ^' tfi O T-I CD I> co" 00 i-J CJ .^ m j>. CO ^* CD 1O ^J lO OlOCiCO -r-iOO^-QO GOIOO?^ co' 06 1-1 "* eo -* o co so -^j i> TH O TH 00 & TM TJH -rji OS eo'co'co'^ ^'eo'cvj^ ?J8Sc? ~ OOCDTH QOCSCS lOlO^* CD o m cdm'in cs' t~ 06 1 i i i 11 i.i o : Averages calculated up tea, unless otherw 5 P o 1 1 11 i a I 2 J i i i &i i H i i &S 1 IP fi Swc; ScScS 4 'S c5 c3 *M "2 o3 c3 3 *S fe c3 3 8* 4 4 8 S 5 ^ li^< TEAS OF COMMERCE. 509 -Off UOIUWOO S 88 T-i oi ctioswx POOQ 2 8 S 8 ot eo' 8 ~ 6UIUOJ\[ UlMp9f * . 2 oJ noSttoo Sum noBitoj Suojoo fiouiy ijuinp * o S s *i g ol s s s ~ nouiy wnipajf 'BtlOJOQ VHOUl ot eo Guojoo vsout Suojoo vsoui S S S 32 -wof uudvf S S S 0? g d & o7 I 8 -fiOff UOW1UOO S S umpuj "D9J, umpuj 5Ppl vsi^i Ijlji ~r ^ ^ *d 2r *" 5io TEAS OF COMMERCE. the same conditions. The results cannot be considered absolute, but, as they vary only between narrow limits, they are sufficiently accurate to illustrate the behavior of these various teas when subjected to the customary household method of pouring boiling water upon the leaves and allowing it to draw. The results of this table (III.) give the percentages of " ex- tract," theine, tannin, 1 ash (mineral matter) dissolved, the alka- linity of the ash expressed as potassium oxide, and the ratio (per cent.) of "extract" and tannin to the total amount of these two in the leaf. The percentages are calculated upon the air-dried leaf. A comparison of the results for the five Oolong teas shows the finer grades to have yielded more extract, theine, and ash than the poorer grades. The decline, from the fine to the poor grades of the various teas, in the amount of theine dissolved, is something noteworthy, as showing the fine grades to yield nearly all their theine, while the poorer grades do so only to a limited extent. The percent- ages of tannin are quite irregular. Further, the table shows that there is more mineral matter extracted from the leaf than is indicated by the term " soluble ash " in Table I., the difference being .62 per cent, as an average of fourteen determinations. The ratio of tannin to the " extract," and the ratio of either one to the total tannin and "extract" of the leaf, varies quite uniformly with the value of the tea, the per cent, of tannin fall- ing or rising with the percentage of u extract." See Table IV. It will also be noticed that the Congou teas yielded low per- centages of " extract " and tannin, showing that the time allowed for drawing in these teas should be greater than ten minutes, if a full yield of these constituents is desired. If this is uniformly true of Congou teas, they would certainly be suitable for people to whom the large quantity of tannin of the other varieties is objectionable. The tannin extracted from the best green tea was unusually large, being 16.79 per cent. Both Indian teas show a good yield of " extract," theine, tan- nin, and soluble mineral matter. Although these results are quite satisfactory in showing the difference in the drawing quali- ties of various-priced teas, they are not sufficiently uniform to make the results of an analysis the basis for calculating the price of a tea. It is evident that the essential oil plays a more impor- tant part than any other constituent of the tea in determining its commercial value. 1 The percentages of tannin are somewhat greater than would be obtained in using a hard water. TEAS OF COMMERCE. TABLE IV. Showing the per cent, of extract, tannin, theine, and ash dissolved from tea by dis- tilled water and Croton water, by allow- ing to draw from three minutes to over one hour. ( One hundred parts of boiling water were poured upon one part of tea.) FINEST FORMOSA OOLONG. 3m. Distilled water. 5m. Distilled water. ti 5 | tf o i ll < Per cent, extract, total 25.97 82.25 9.755 1.95 1.029 3.725 28.37 24.50 11.23 2.65 1.22 3.805 27.47 23.85 10.18 2.02 1.076 3.625 30.87 26.70 13.46 2.75 1.22 4.175 30.25 26.12 10.60 2.82 1.152 4.125 33.75 29.42 14.94 2.85 1.28 4.325 Per cent, extract, less ash. Per cent tannin Per cent theine Alkalinity of ash as potassic oxide Per cent, ash Table IY. illustrates the difference in the drawing quality of an extra choice Oolong tea when treated either with distilled or Croton water. It shows that in ten minutes' " drawing " the theine was practically extracted, and that the Croton water ex- tracted less tannin than the distilled water, while there was no noteworthy difference in the percentages of extract and ash when the distilled water and Croton water were allowed to draw for the same length of time. Hard waters dissolve less tannin than soft waters under the same conditions. This will also be noticed in the above table. And Table IY. serves to illustrate the rapidity with which the constituents of the tea leaf are dissolv- ed, and that the choice of the water and the proper length of time for drawing are very important factors in preparing a good cup of tea. Practical conclusions. Though varying widely for different teas, the total soluble (extractive) matter averages about 33 per cent., but the average is considerably lower for the infusion of tea prepared by the ordinary household method. The volatile oil gives the flavor and aroma, the tannin and extractive matter the astringency, strength, and body to the infusion. Theine, being almost tasteless, is not taken into account by " tea-tasters," though, physiologically, the most important constituent of the tea. Besides the above, the appearance of the leaf, as well as the color of the infusion and any peculiar foreign taste or smell imparted to the same, have considerable bearing in the " tea- 5 1 2 THEOBROMINE. taster's " method of valuation. A strict relation between the chemical composition of the tea and the commercial value of the same is therefore scarcely to be looked for, although the former would disclose at once that tea which is physiologically the best. The principal constituents of tea are the volatile oil, theine, tannin, albuminous compounds, gum, etc., and the soluble mineral matter, containing considerable potash and phosphoric acid. The fertility of the soil, the nature of the climate, the pro- cessing and manipulation the leaves undergo after being pluck- ed, and the care with which the tea is handled thereafter are all instrumental in influencing the chemical composition and the quality of the tea. Uniformity in composition cannot be ex- pected. The principal difference between Green, Oolong, and Congou teas is caused by the processing and manipulation ; but, whatever the modus operandi of the latter, it cannot make good tea out of leaves which have not had the proper conditions of soil and climate to further the production of those constituents which are characteristic of tea. In the ordinary analysis of the tea only the more important constituents are determined, in order to establish the presence or absence of foreign matter. The results thus obtained are scarcely applicable to the commer- cial valuation of tea, since much is there determined which does not enter the infusion of tea. It is the quality of the infusion which is of importance to the consumer, and not the total com- position or appearance of the leaf. Tea is essentially something for the epicurean. To discriminate between qualities of teas of nearly the same grade requires a delicate and sensitive palate. Expert tea-tasters are guided chiefly by the strength, flavor, aroma, and quality of the infusion in judging and classifying tea as to its quality. THALLINE. See CINCHONA ALKALOIDS, p. 168. THEBAINE. See OPIUM ALKALOIDS, p. 358. THEINE. See CAFFEINE, p. 77. THEOBROMINE. C 7 H 8 K 4 O 2 = 180. A dimethyl xan- thine, C 5 H 2 (CH 3 ) 2 N 4 O 2 . See Caffeine, p. 77. Found, without caffeine, 1 in the seed of the Theobroma Cacao, or " chocolate 1 SCHMIDT (1883) found a little caffeine in cacao. THEOBROMINE. 513 nut " (WOSKRESENSKY, 1841), and, as a smaller accompaniment of caffeine, in the seed of the Sterculia acuminata, the " cola nut." The dry cacao seed freed from husk, the " cocoa nibs,' 7 contains about 1.5 per cent, of theobromirie (WOLFRAM, 1879) ; while the husks, the u cocoa shells," furnish from 0.3 to 0.7 per cent, in average yield (A^OLFRAM, DONKER, 1880). a. Theobromine crystallizes in the trimetric system, appear- ing in permanent, anhydrous white needles and club-shaped groups, to the unaided eye as a crystalline powder. Sublimes without decomposition, yielding distinct microscopic crystals of sublimate at 170 C. (BLYTH, 1878). Sublimes at 290 to 295 C. (KELLER, 1854). b. Theobromine has a very bitter taste, slowly produced. Its physiological effects are like those of caffeine, but are ob- tained by smaller doses (MITSCHERLICH, 1859). It is excreted in the urine. c. Theobromine is slightly soluble in water or alcohol, its solution requiring 1600 parts water at 17 C. (62.6 F.), and 148 parts water at 100 C. (DRAGENDORFF) ; 4284 parts absolute alco- hol at 17 C., and 422 parts boiling absolute alcohol (TREUMANN, 1878), in 1400 parts cold alcohol (MITSCHERLICH, 1859). It is but very slightly soluble in ether, one part requiring 17000 parts cold ether or 600 parts boiling ether (Mitscherlich). It dissolves in 105 parts boiling chloroform (Treumann) ; is somewhat solu- ble in amyl alcohol ; but slightly soluble in benzene ; insoluble in petroleum benzin. Theobromine is a weak base. It forms crystallizable salts ; but on contact with water they give up acid and become basic salts, and those of volatile acids give up the acid at or below 100 C. Theobromine dissolves in hydrochloric and in other acids ; but the hydrochloride, C 7 H 8 N 4 O 2 . HC1 . H 2 O, and the nitrate, C 7 H 8 N" 4 O 2 .HNO 3 , do not dissolve at all freely in water alone without free acid. Theobromine dissolves in ammonia-water. Respecting combinations, see report of Messrs. SCHMIDT and PRESSLER, 1883. 1 d. Theobromine responds to the murexoin test with the same intensity as Caffeine (p. 79), forming amalic acid when warmed with hydrochloric acid and potassium chlorate and evaporated to dryness on the water-bath, and giving purple- colored murexoin when the cold residue is touched with am- monia. Phosphomolybdate of sodium, added to the acidulous 1 Liebig's A?malen, 217, 287; Jour. Chem. JSoc., 44, 872. 5 i4 TYROTOXICON. solutions of theobromine, gives a jellow precipitate, obtained in dilute solutions. Platinum chloride does not precipitate, except in concentrated solutions, when crystals are obtained, (C 7 H 8 N 4 O 2 ) 2 HClPtCl 6 .4H 2 O. In like manner gold chloride yields yellow crystals, in tufts of needles, C 7 H 8 N 4 O 2 . HC1 . Au01 3 . When an ammonia solution of theobromine is treated with silver nitrate solution, a gelatinous precipitate is obtained, and on boiling this granular crystals of argentic theobromine are ob- tained, C 7 H 7 AgN 4 O 2 . And when this compound is treated with anhydrous methyl iodide, at 100 C., for twenty-four hours, caffeine (methyl theobromine) is formed, with silver iodide (STRECKEE, 1861). Again, when theobromine, alcoholic solution of potassium hydrate, and methyl iodide, in equiva- lent quantities, are heated together at 100 C. in sealed tubes, caffeine is formed, with potassium iodide (SCHMIDT and PRESSLER, 1883). C 7 H 7 AgN 4 O 2 + CHJ = C 7 H 7 (CH 3 )K 4 O 2 + Agl C 7 H 8 ISr 4 2 + OH 3 I + KOH = C 7 H 7 (CH 3 )N 4 2 + Kl + H 2 O. Potassium mercuric iodide produces no precipitate in the acidu- lous solutions of theobromine, and iodine in potassium iodide solution causes little precipitation (distinctions of caffeine and theobromine from most other alkaloids). e. Theobromine may be separated from non- volatile mat- ters, like caffeine, by sublimation at a gradually increasing heat beginning at 170 C. From most alkaloids by its slight solubi- lities, and from caffeine by its smaller solubilities in benzene (SCHMIDT), or water, or ether. f. The quantitative estimation of theobromine in cacao is made by SCHMIDT and PRESSLER (1883) as follows : The crushed cacao is freed from oil by pressure, half its remaining weight of slaked lime is added, and the mixture is boiled repeatedly with alcohol of 80 per cent, strength. The residue on evapora- tion of the alcohol is recrystallized from the same solvent, and is obtained as a white, crystalline powder. It may be dried at 100 C. and weighed. TROPEINES. See MIDRIATIC ALKALOIDS, p. 339. TURKEY-RED OIL. See FATS AND OILS, p. 287. TYROTOXICON." Cheese Poison." The putrefactive product obtained in 1885 by Professor Vaughan, and recently TYROTOXICON. 515 announced by him to be diazobenzene, C 6 H 5 .N:N, in combina- tion with acids. 1 a. Tyrotoxicon, obtained from milk products as direct- ed under e, was found to agree with diazobenzene butyrate, C 6 H 5 . No. C 4 H 7 O 2 , in crystallizing in needles, which gradually decompose in moist air. Potassium diazobenzene, C 6 H 5 . N 2 . OK, obtained from tyrotoxicon, 3 appeared in tine six-sided plates. Tyrotoxicon compounds, at 100 C., explode with violence. b. The crystals have a penetrating, old-cheesy odor. A minute portion placed upon the tongue produces " dry ness of the throat, nausea, vomiting, and diarrhosa." In children the effects agree with the symptoms of cholera infantum. Ten drops of a concentrated aqueous solution of tyrotoxicon from milk three months old, placed in the mouth of a small dog three weeks old, in a few minutes caused " frothing at the mouth, retching, vomiting of frothy liquid, rapid breathing, muscular spasm over the abdomen, and after some time watery stools." Similar ef- fects were obtained with cats, and subsequent dissection showed the mucous membrane of the stomach and intestines to be blanched and soft. Of diazobenzene butyrate, artificially pre- pared, 3 0.010 to 0.025 gram given to cats caused severe symptoms, the same as above detailed, and 0.100 gram caused death, the mu- cous membrane of the stomach not being reddened, but left pale and soft. c. " Tyrotoxicon is soluble in water, alcohol, chloroform, and ether." " Purified tyrotoxicon is insoluble in ether, and it probably owes its solubility in ether at this stage to the presence of impurities." The ordinary salts of diazobenzene are more or less freely soluble in water, sparingly soluble in alcohol, and are for the most part precipitated from alcoholic solutions by ether. d. The diazobenzenoid compounds are identified by the reaction of LIEBERMANN,* namely, by the bright colors they give 1 VICTOR C. VAUGHAN, 1884-85: "A Ptomaine from Poisonous Cheese," Zeitsch. physiolog. Chem., 10, 146; Jour. Chem. Soc., 50, 373. Michigan State Board of Health Reports, 1885 and after. "Tyrotoxicon: Its presence in poi- sonous cheese, ice-cream, and milk," Am. Assoc. Adv. Sci., Buffalo Meeting, August, 1886, Jour. Analyt. Chem., I, 24. "The Chemistry of Tyrotoxicon and its action upon the lower animals," with report of determination of diazo- benzene, ibid., i, 281. J By method of GRIESS, 1866: Ann. Chem. Phar., 137, 54. 3 By the method of GRIESS, loc. cit. 4 LIEBERMANN, 1874: Ber. d. chem. Oes., 7,247; Jour. Chem. Soc., 27, 693 : that sulphuric acid holding nitrous acid in solution gives color-reactions 516 TYROTOXICON. when treated with concentrated sulphuric acid and phenol. " With equal parts of sulphuric acid and carbolic acid the pre- pared [artificial] diazobenzene nitrate gave a green coloration ; while with the same reagents tyrotoxicon gave a color which varied from a yellow to an orange-red. But the diazobenzene nitrate dissolved in the whey of normal milk and extracted with ether, or in the presence of other proteids, gave the same shades of color as the tyrotoxicon did, and the potassium compound of tyrotoxicon prepared by the method to be given later produced the same shade of green as did the artificial diazobenzene. This color test may be used as a preliminary test in examining milk for tyrotoxicon. It is best carried out as follows : Place on a clean porcelain surface two or three drops each of pure sulphuric acid and pure carbolic acid. This mixture should remain color- less, or nearly so. Then add a few drops of the residue left after the spontaneous evaporation of the ether. If tyrotoxicon be present a yellow to an orange-red color will be produced. This test is to be regarded as a preliminary one ; for it may be due to the presence of a nitrate or nitrite. 1 The tyrotoxicon must be purified according to a method to be given further on before the absence of nitrate or nitrite can be positively demonstrated." The explosion of tyrotoxicon may be obtained, in evidence of its identity, by exposure of the platinochloride to a tempera- ture approaching 100 C., as in the discovery of this property by Prof. Yaughan. A solution of the tyrotoxicon in absolute alco- hol is treated with a little platinum chloride, and heated in an open dish upon the water-bath, when, as the alcohol is nearly or quite all vaporized, the explosion results. The known diazo pla- tinum compound is (C 6 H 5 . ~N 2 . Cl) 2 PtCl 4 , and in explosion is resolved into 2C 6 H 5 C1 + N 2 + 2C1 2 + Pt. The aurochloride of tyrotoxicon is obtained, in precipitate or in golden plates, as follows : " In the filtrate from milk which is rich in tyrotoxicon, after neutralization with sodium carbonate, with phenols generally, the produced colors containing nitrogen but not in the form of the nitro, and probably not in that of the nitroso group. All diazo compounds, also the diazo-amido compounds, share with the ni- troso compounds (Hofmann) and the nitrites (Liebermann) the power to give with sulphuric acid and phenol red to blue colors of the utmost intensity (E. FISCHER, 1875). The color-products so obtained are azo-benzenoid bodies, well known as azo dyes, represented by the tropo?olines (this work, p. 186; 0. N. WITT, Jour. Ghent. Soc., 35, 179). The azo compounds, it will be remembered, contain the group NN interposed between two benzenoid (or other carbona- ceous) groups. Thus, C 6 H 4 . N 2 . S0 3 (diazobenzene sulphonic acid)-f-C 6 H 5 OH = C 6 H4.SO3H..N2.C 6 H4.0H (oxy-azo-benzene sulphonic acid). 1 " The coloration with nitrates and nitrites is darker than with diazoben- TYROTOXICON. 517 filtration and acidifying with hydrochloric acid, gold chloride produces a precipitate which is insoluble in water, but soluble in hot alcohol, from which it separates, on cooling, in golden plates." 4 ' The gold compound is decomposed by frequent treatment with hot alcohol." The potassium compound of tyrotoxicon believed to be po- tassium diazobenzene, C 6 H 5 . E" 2 . OK was prepared as follows : " The aqueous residue [see e] was acidified with nitric acid, then treated with an equal volume of potassium hydrate and the whole concentrated on the water-bath. . . . On cooling the mass crystallized ... in six-sided plates, along with the prisms of po- tassium nitrate. The crystalline mass obtained from the tyro- toxicon was treated with absolute alcohol, filtered, the filtrate evaporated on the water-bath, the residue dissolved in absolute alcohol, from which it was precipitated in a white, crystalline form with ether." The decompositions of tyrotoxicon are so far found by its discoverer to agree with the well-known decompositions of diazo- benzene salts. Warmed with water the latter break up into car- bolic acid and nitrogen, thus : C 6 H 5 . ]ST 2 . NO 3 + H 2 = C 6 H 5 . OH + N 2 + HNO 3 . "Warmed with alcohol, aldehyde and hydrocarbons result as fol- lows : C 6 H 5 . K 2 . N0 3 + CoII 6 = C 6 H 6 + K 2 + C 2 H 4 + HNO 3 . With the acids of the halogens changes occur as follows : C 6 H 5 . N 2 . NO 3 + BLC1 = C 6 H 5 C1 + N 2 + HN0 3 . The reducing agents in general cause immediate decomposition. Hydrogen sulphide reacts promptly. e. The following directions for the separation of tyrotoxicon from milk or cheese are taken from the last article of Dr. Yaughan : " Milk or other fluid to be tested for this poison should be kept in well-stoppered bottles; for if the fluid be ex- posed to the air the tyrotoxicon may decompose in a few hours. The filtrate from the milk, or the filtered aqueous ex- tract of cheese, should be neutralized with sodium carbonate, then shaken with half its volume of pure ether. Time should be given for the complete separation of the ether. . . . After complete separation the ether should be removed with a pipette and allowed to evaporate spontaneously in an open dish. The residue from the ether may be dissolved in distilled water and again extracted with ether ; but repeated extractions with ether are to be avoided, for as the tyrotoxicon becomes purified it be- 5i8 VALERIC ACIDS. comes less soluble in ether. To a drop of an aqueous solution of the ether residue apply the preliminary test with sulphuric and carbolic acids. To the remainder of the aqueous solution of the ether residue add an equal volume of a saturated solution of caustic potash, and evaporate the mixture on the water-bath. The double hydrate of potassium and diazobenzene [C 6 H 5 .N 2 .OK] will be formed if tyrotoxicon be present." The recognition of potassium diazobenzene is stated on page 517. f. An estimation of tyrotoxicon is indicated by the experi- ments of Vaughan, in converting the potassium compound (d), prepared as directed (e), into potassium sulphate for weight. The white, crystalline precipitate, by the ether, " was collected, washed with ether, dried, and the per cent, of potassium esti- mated as potassium sulphate.'' ! K 2 SO 4 : 2C 6 H 5 N 2 OK : 2C 6 H 5 N 3 NO 3 ::174 : 320 : 334. ULTIMATE ANALYSIS OF CARBON COMPOUNDS. See p. 201. VALERIC ACIDS. C 5 H 1Q O 2 = 102 (monobasic). Pri- mary Pentoic Acids. Four pentoic acids are theoretically pos- sible, as oxidation products of the four primary pentoic alcohols, and are all known, as follows : (1) Normal valeric acid, CH 3 .CH 2 .CH 2 .CH 2 .CO 2 H. Made from normal butyl cyanide, etc. (2) Iso valeric acid. Inactive valeric acid. (CH 3 ) 2 CH . CH 2 . CO 2 H. Isobutyl-carboxyl. Chief valeric acid of vale- rian oil. Obtained by oxidation of the chief alcohol of fusel oil. (3) Methyl-ethyl acetic acid. Active (dextro-rotatory) valeric acid. CH 3 .C 2 H 5 .CH.CO 2 H. In small proportion in valerian oil, according to some observers. Obtained by oxidation of the lesser pentyl alcohol (13$) of fusel oil. (4) Methyl-propyl acetic acid, CH 3 C 3 H 6 .CO 2 H. Made from me thy 1-propy 1- carbin ol . ORDINARY VALERIC ACID. ISOVALERIC ACID. Inactive Yaleric Acid. The second of the pentoic acids above named. Baldriansaure. A constituent of " valerian root," the rhizome and rootlets of Yaleriana officinalis, and a part of the volatile oil of valerian. Reported as found in digitalis, Artimisia Absin- 1 Per cent, of potassium calculated, 24.42; found, 23.92. ORDINA R Y VA LERIC A CID. 5 1 9 thium, Anthemis nobilis, Sambucus nigra, Viburnum opulus, and other plants. Manufactured by oxidation (distillation from dichromate and sulphuric acid) of isoamjl alcohol (isobutyl car- binol), the principal alcohol of fusel oil. Valeric acid is recognized by its odor and the odor of amyl valerate (6), its solubilities (c, d\ and physical properties (a). It is separated by distillation or by shaking out with ether (e). It may be estimated volu metrically (/). Tests of purity (g). a , Isovaleric acid, absolute, is a colorless oil, of specific gravity 0.937 at 15 C. ; 0.931, to 0.933 at 20 C. (water at same) (LANDOLT, 1862). It boils at 175 C. (FRANKLAND and DUPPA, 1867). It forms a hydrate, C 5 H 10 O 2 .H 2 O, of ^sp. gr. 0.950, boil- ing at 165 C., and gradually dehydrated by distillation. The metallic valerates are easily fusible salts, congealing with an opaque white surface, and crystallizing by careful concentra- tion of solutions. b. Isovaleric acid has an acidulous, burning taste, and a bit- ing effect on the tongue. The odor is characteristic, unpleasant, reminding of rancid cheese. The metallic valerates are nearly odorless, and of a sweetish, sharp taste. Ethyl and amyl vale- rates have fragrant, heavy fruity odors. Amyl valerate is used to present an odor of apples. c. Isovaleric acid is soluble in about 30 parts of water at ordinary temperatures, the hydrate somewhat more soluble. By saturation of the solution with calcium or sodium chloride the valeric acid is almost wholly thrown out of solution. It is solu- ble in all proportions of alcohol, ether, chloroform, or glacial acetic acid. The valerates of the alkali metals are deliquescent and freely soluble in water and in alcohol; of the alkaline-earth metals, moderately soluble in water and in aqueous alcohol. Aluminium valerate is not soluble in water; basic ferric valerate, insolu- ble ; zinc valerate, in 90 parts of water or 60 parts of 80$ alco- hol ; bismuth valerate (basic), insoluble in water ; lead valerate, (normal) soluble in water, (basic) sparingly soluble ; mercuric valerate, soluble ; mercurous valerate, slightly soluble ; cupric valerate, moderately soluble ; silver valerate. slightly soluble, in water. To test-papers free valeric acid has the acid reaction; the alkali valerates, neutral reaction. < Isovaleric acid is characterized by its odor as a free acid, and by the odor of its amyl ester. This is formed by distilling with a little ordinary amyl alcohol and twice its quantity of 520 VALERIC ACIDS. sulphuric acid. Precipitates are obtained, with alkali valerates, on adding aluminium sulphate or silver nitrate, not by addition of lead normal acetate. Cupric acetate, with concentrated free valeric acid, yields oily droplets of anhydrous valerate of cop- per, which, on standing, crystallize as hydrate (distinction from butyrate, which in solution not very dilute idves an immediate precipitate of butyrate of copper). e. Separation. Iso valeric acid is separated from non-vola- tile matters, and obtained from its salts, by distillation, adding diluted sulphuric acid if necessary to liberate it. From other volatile acids fractional saturation and distillation may be em- ployed, having regard to boiling points. Separation from aqueous solutions is effected by ether more readily than by distillation. The aqueous solution, in which the valeric acid is liberated, if need be, by adding potassium bisulphate, is saturated w r ith sodium sulphate and shaken out with portions of ether. f. Quantitative. The valeric acids may be estimated volu- metrically with standard solutions of alkali, using either litmus- papers or phenol-phthalein as the indicator of saturation. Each c.c. of normal solution of alkali indicates 0.102 gram of real valeric acid ; each c.c. decinormal solution, 0.0102 gram. And if 5.1 grains of material be taken, c.c. of N alkali X 2 = per cent, of acid ; if 1.02 grams be taken, c.c. of T N F = per cent. g. Tests of Purity. "Purified by distillation, valeric acid is a colorless liquid, oleaginous, of a peculiar disagreeable odor. It dissolves in 30 parts of water at 20 C., and in all proportions of alcohol or ether. Its specific gravity at C. is about 0.955. It boils at 175 C."(Ph. Fran.)" A specific gravity above 0.950, and solubility in less than 25 parts of w^ater, indicates pre- sence of water, acetic or butyric acid, amyl alcohol or aldehyde. The last two are known by their insolubility in ammonia-water. If half of a mixture of equal parts of butyric and valeric acids be neutralized with alkali, and the whole distilled together, the butyric acid goes over, and will be found soluble in not above 10 parts of water " (Fliickiger's " Pliar. Chem.") VAPOR TENSION, DETERMINATION OF. See p. 237. VINEGAR. See ACETIC ACID, p. 14. INDEX. Abies Canadensis, tannin of 481 Absinthin 7 Absinthin, in plant analysis 425 Acetate of lime 11 Acetate of sodium 11 Acetic acid. 7 Acid Azo-rubin 184 Acid Magenta 184 Acid Naphthol Yellow 185 Acids, organic, in plant analy- sis 415,419, 424 Acid tartrate of potassium 496 Aconelline. 387 Aconine 18 Aconite assay 27 Aconite roots 19 A conitic add 30 Aconitic acid from citric 86 Aconite alkaloids 17 Aconitine 17 Aconitine poisoning, analysis for. 28 Aconitine, saponification of 171 Aconitines of commerce 30 Aconitum, aconitic acid in 30 Aconitum, species of 19 JEsculin 31 Air-pump for combustions 222 Albumens, in plant analysis . . . 416, 420, 425 Alcoholic beverages, analysis of, for strychnine 460 Alcohols in fusel oil 315 Alder tannin 481 Ale, analysis of, for strychnine. . 460 Alizarin 189, 197 Alkali blue 187 Alkaloid*, color-tests of 50 Alkaloids, in general. 32 Alkaloids, in plant analysis. .418, 424 Alkaloids, reagents for 42 Alkaloids, separation of 33 Alkanet 194 Alkanna- violet 194 Alloxantin 80 Alnus glutinosa, tannin of 481 Aloes dye 188 Aloes, tests for. 56 Aloes, varieties 54 Aloins 54 Amalic acid. . . . 80 Amethyst 188 Amido-azo-benzol 185 Amido-succinamic acid 58 Amido-succinic acid 58 Amphicreatinine 428 Arnygdalic acid 57 Amygdalin 56 Amygdalin in color-tests with sul- phuric acid 50 Amyl alcohols 315 Analysis, inorganic and organic. 393 Analytical chemistry of carbon compounds 391 Andromeda Leschenaultii, oil of. 433 Aniline blue 187, 197 Aniline brown. 197 Aniline dyes with immiscible sol- vents 195 Aniline dyes in inks. , 482 Aniline green 194 Aniline orange 197 Aniline reds 189, 191, 197 Aniline violet ..... 197 Aniline yellow 197 Anisol-red 184 Annatto 193 Anthemis nobilis 519 Anthracene oil, a fraction from coal-tar 395 Antipyrine 1 63 521 522 INDEX. Apo-alkaloids of the Aconites. . . 19 Apo-dicinchonine 91 Apo-diquinidine 91 Apomorphine 390 Apomorphine in color-tests with sulphuric acid 50 Apoinorphine in color-tests with Froehde's reagent 51 Arbutin 57 Archil 192 Argols 496 Aricine 92 Arsenic, qualitative analysis for. . 200 Artemisia absinthium 7, 518 Ash, estimation of 410 Asphalt, a fraction from coal-tar. 395 Asparagin 58 Aspartic acid 58 Atropine 344 Atropine, saponification of 171 Atropine, tests of purity of 357 Auramin 185 Auric chloride with alkaloids. ... 49 Azo color compounds 186 Azo compounds from Lieber- mann's test 516 Azotometer, Schiffs 221 Baking-powders 500 Baldriansaure 518 Balsams containing cinnamic acid 69, 71 Barbaloin 54 Bebirine 58 Beer, analysis of, for salicylic acid 440 Beer, analysis of, for strychnine. 460 Beeswax, melting and congealing points 271 Belladonna, alkaloids of 340 Belladonna assay 351 Belladonna extract, assay of 353 Belladonna plasters, assay of. ... 353 Belladonna root or leaves, assay of 351 Bengal-red 183 Benzene, certain derivatives of. . 434 Benzoates. . 62 BenzoSsaure 59 Benzoic acid 59 Benzoic acid, tests of purity of. . . 66 Benzoin 59 Benzoyl-ecgonine 170, 173 Benzyl fluorescein 185 Berberine 71 Betaine 428 Biberine 58 Bichromate, for combustions. . . . 210 Biebrich scarlet 184 Bismarck brown -. . . 186 Bitartrate of potassium 496 Bitter-almond oil, relation to ben- zoic acid 60, 63 Blue coloring matters 187 Blue inks 482 Bohea 504 Bone fat, sp. gr. and melting of . . 274 Bordeaux blue 184 Borosalicylic acid 438 Boheatannic acid 481 Boheic acid 481 Brazil-wood color 193 Brazil-wood in inks 482 Bromine, estimation of 236 Bromine, qualitative analysis for. 200 Bromine reactions with alkaloids 47 Brucine 463 Brucine in color-tests with sul- phuric acid 50 Brucine in color-tests with Froehde's reagent 51 Brucine in color-tests with ni- tric acid 52 Brucine separation from strych- nine. 458 Butter 293 Butter-analysis, competence of. . . 310 Butter-analysis, interpretation of 300 Butter, artificial colors of 295 Butter, estimation of rancidity of 295 Butter-fat 298 Butter-fat, methods of analysis of 300 Butter, microscopic analysis of. . . 297 Butter, odor- test of .....' 298 INDEX. 523 Butter, salicylic acid in 441 Butter-soaps, viscosity of 297 Butter substitutes 300 Butyric acid 75 Buxine 58 Cacao butter, melting of 269, 272 Cadaveric alkaloids 426 Cadaverine 427 Caffeine 77 Caffeine from theobromine 514 Caffetannic acid 480 Caffetannin 480 Calcium tartrate 498 Camphors, in plant analysis 418 Canned fruits, analysis of, for salicylic acid 440 Cantharides, assay of 84 Cantharidin 83 Capric acid 245 Caproic acid 245 Caprylic acid 245 Capsicum, in plant analysis 425 Carbolates 398, 401 Carbolic acid 396 Carbolic acid, assay of 404 Carbolic oil, as a fraction from coal-tar 395 Carbolsaure 396 Carbon and Hydrogen estima- tion 208, 219 Carbon, qualitati ve analysis for. . 198 Carius's method for halogens or sulphur 236 Caryophyllin, in plant analysis. . 425 Cascarilline, in plant analysis 425 Castor oil 289 Castor oil, melting of fat acids of 269 Castor oil, tests of purity of 290 Catechin 479 Catechutannic acid 479 Catechutannin 479 Celandine, constituent of 84 Cell formation not a direct result of chemism 391 Cellulose, in plant analysis, 417, 421, 426 Cevadine, saponification of 171 Chairamidine 92 Chairamine 92 Cheese poison 514 Cheese poison, as a ptomaine. . . . 429 Chelidonine 84 Chestnut-red 482 Chestnut tannin 482 Chinidine 154 Chinin 125 Chinoidine 94 Chinoline 165 Chinophtalon 185 Chitenine 128 Chloride of calcium, for analysis. 205 Chloride of calcium tubes 206 Chlorine, estimation of 236 Chlorine, qualitative analysis, for 200 Chlorophyll, in plant analysis, 418, 424 Chocolate nut 512 Choline 427 Chromate in inks 482 Chromate of lead, for combus- tions 203, 210 Chrysammic acid 56, 188, 197 Chrysoidin 186 Cider, analysis of, for salicylic acid 440 Cinchamidine 93 Cinchona Alkaloids 90 Cinchona alkaloids, constitution of 97 Cinchona alkaloids, yield of 96 Cinchona assay 102 Cinchona barks, alkaloidal strengths of 96 Cinchona barks, assay of 102 Cinchonamine 92 Cinchonicine 91 Cinchonidine 157 Cinchonidine salts 158 Cinchonidine, tests of purity of. 159 Cinchonine 161 Cinchonine salts. . . 162 INDEX. Cinchonine, tests for purity of . . . 164 Cinchotannic acid 479 Cinchotannin 479 Cinchotine 93 Cinnaraates 69, 70 Cinnamein 71 Cinnamene 71 Cinnamic acid 69 Cinnamic aldehyde 69 Cinnamon oil, relation of 69 Citracohic anhydride 31 Citrates 86 Citric acid 85 Citric acid, tests of purity of 89 Citronensaure 85 Citronin 186 Coal-tar distillation, fractions from 395 Coca Alkaloids 170 Cocaicine 172 Cocaine 170, 174 Cocaine hydrochloride . . 174, 175, 180 Cocaine salts 174, 175 Cocaine, tests for purity of 180 Cocainoidine 170, 172 Coca leaves, assay of 178 Cochineal 193 Cochineal violet 194 Cocoa nibs 513 Cocoanut oil, melting of 269, 274 Cocoa shells 513 Codamine 359 Codeine 388 Coffee, assay of 81 Coffee, tannin of 480 Coffein 77 Cola nut, assay of 81 Cola nut, theobromine in 513 Colchicine in color-test with sul- phuric acid 50 Colchicine in color-test with Froehde's reagent 51 Colchicine, in plant analysis 425 Colocynthin in color-tests with Froehde's reagent 51 Colocynthin, in plant analysis. . . 425 Colombin in color-tests with sul- phuric acid : 50 Coloring Materials 181 Coloring matters of butter 295 Color-reactions of the alkaloids. . 50 Colors, in plant analysis 419 Combustion-furnaces 208, 216 Combustions, analytical 201 Combustion tubing 206 Conchairamidine 92 Conchairamine 92 Conchinine 154 Concusconidine 93 Concusconine 92 Congo-red 184 Conine in color-test with sulphu- ric acid 50 Conquinaraine 92 Convallamerin, in plant analysis. . 425 Copper, for combustions 204 Copper oxide, for organic combus- tions 202 Coptis, per cent, of berberine in. . 73 Copying inks 483 Corallin 196, 197 Corallinred 191 Corulein 186, 196 Cotarnine 360, 388 Cotton-seed oil 287 Cotton-seed stearin 289 Cranberries, constituent of 85 Cream of Tartar 496 Creosote, compared with carbolic acid 394, 401 Creosote oil, of coal-tar distilla- tions 395 Cresols 394 Cresol-sulphonic acids 406 Cresotic acids 434, 443 Cresylic acid 394 Crocein scarlet 184 Cruscocreatinine 4^8 Cryptopine 360, 362 Cryptopine in color-test with sul- phuric acid 50 Crvsolin. . . 185 INDEX. 525 Cubebin in color-tests with sulphu- ric acid 50 Cubebin, in plant analysis 425 Cuprea barks, constituents of 92 Cupreine 92 Cupreine, test for 153 Gurarine in color-test with sulphu- ric acid 50,52 Curarine interference with strych- nine test 454 Curcumin dye 185 Cusconine 92 % Dalican's method for fats 252 Daphnin, in plant analysis 425 Daturine 340, 341, 344 Dead oils of coal-tar distillations. . 395 Deduction of chemical formulae. . . 237 Delphinine, in plant analysis 425 Dextrines, in plant analysis. . 420, 425 Dextrotartaric acid 485 Diazobenzene compounds 515 Diazo color compounds 184 Dichonchonine 91 Dicinchonicine 91, 95 Diconchinine 91 Digallic acid 474 Digitalein, in plant analysis 425 Dihydroxyl-quiniiie 128 Dimethyl-amido-azo benzol 185 Dimethyloxyquinizine 16r> Dimethylprotocatechuic acid 18 Dimethyl xanthine 212 Diphenylamine yellow 186 Diquinicine 91, 95 Dragendorff' 's plan for plant analysis 423 Dragendorff's process for alka- loids 33 Drying oils 281 Duboisia, alkaloids of 340 Duboisine 340 Ecgonine 170, 172 Eisessig 8 Elaidic acid. . . 247 Elaidin test 281 Elaterin in color-tests with Froehde's reagent 51 Elaterin in color-tests with sul- phuric acid 50 Elaterin, in plant analysis 425 Elementary analysis 198 Elementary analysis, inorganic and organic 392 Elementary organic analysis, quantitative 201 Eosins 183 Bosiu scarlet 183 Ericolin, in plant analysis 425 Erlenmeyer's furnace 208 Erythroxylon Coca 170 Essigsiiure 7 Essigsauren Kalk 11 Ethyl-orange 186 Extraction apparatus 409- Extraction-apparatuses for liquids (illustrated) 38 Extract of belladonna, assay of. . . 353 Extract of nux-vomica, assay of.. 457 Fat acids, percentages of, insol- uble 256 Fat acids, quantitative determina- tions of 250 Fat oils, specific gravity of 262 Fats and Oils 238 Fatty acid series 239, 245, 246 Filter of Gooch 409 Flavanilin 185 Fleischer's estimation of tartaric acid 495 Formic acid 312 Formulas, deduction of 237 Froehde's reagent for alkaloids. .. 51 Fruits, percentage of citric acid in 85 Fusel oil. 314 Fustic color 193 Fustic tannin 479 Gadinine 427 5 26 INDEX. Gallein 183 Gallic acid 320 Gallic anhydride 474 Gallo-cyanin 188 Gallotannin 474 Gaseous bodies, organic combus- tions of 216 Gaultheria, oil of 433 Geisler's report on teas 505 Gelseminine in color-test with sul- phuric acid. 50 Gelseminine in color-test with ni- tric acid 52, 454 Gelsemine, in plant analysis 425 Gerbsauren 465 Gerland's method for estimating tannins 471 Gerrard's test for atropine 348 Glacial acetic acid 8, 14 Glaser's combustion furnace 216 Glucose, in plant analysis. . .415, 419, 425 Glucosides, in plant analysis.. 413, 419, 424 GJucoside-tannins 466 Glycerides, as a chemical class . . . 238 Glycerin 323 Glycerin, tests of purity of 328 Gnoscopine 360 Gnoscopine in color-test with sul- phuric acid 50 Gold chloride with alkaloids 49 Gooch's filter 409 Gratiolin, in plant analysis 425 Green Coloring Matters 186, 193 Green oil or anthracine oil 395 Guarana, assay of 81 Guaranine 77 Gums, in plant analysis 416, 420 Hager's method for estimating tannins 472 Halogens, estimation of 236 Hammer's method for estimating tannins 473 Hard pitch 395 Hectographic ink 483 Hehner's method for fats ..... 250 Hehner's number, interpretation of 301 Helleborin, in plant analysis 425 Hemepic acid 362 Hemlock bark, tannin of 481 Hempseed oil, drying test of 282 Helvetia green 187 Herapathite 131 Hesse's test for quinine sulphate.. 151 Hippuric acid in urine 62 Hippuric acid, source of benzoic.. 60 Hof mann's violet 188 Holzessigsauren Kalk. 11 Homatropine 343 Homocinchonidine 93 Homoquinine 92 Hop bitter, in plant analysis 425 Hop-tannin 481 Hiibl's method with fats 258 Humus, in plant analysis 417, 420 Hydrasiine 329 " Hydrastine," yellow alkaloid. . . 72 Hydrastis, assay of 74 Hydrastis, constituent of 72 Hydrocinchonidine 91 Hydrocinchonine 93 Hydroconquinine 93 Hydrocotarnine 360, 362 Hydrocyanic acid, from amygda- lin 57 Hydrogen, estimation of 208 Hydrogen, qualitative analysis for 198 Hydroquinidine 91 Hydroquinine 91 Hydroxy-benzoic acids 433, 443 Hydroxy-xylenic acids 443 Eygrine .170, 173 Hyoscine 342 Hyoscyamine 342 Hyoscyamus, alkaloids of 340 Hyoscyamus assay 353 Hyoscyamus leaves and seeds, assay of 353 INDEX. 527 Hypogaic acid 246, 249 Igasurine 446 Immiscible solvents 33 Inactive valeric acid 518 Indelible inks 483 India-ink 482 Indigo-blue 192 Indigo-carmine 188 Induline R 188 Inks 482 Ink-stains, discharge of 484 Inorganic analysis, relations to organic 393 Inorganic substances, in organic analysis 200 Inulin, in plant analysis 425 Iodine and methyl green 187 Iodine, estimation of 236 Iodine numbers of fats 258 Iodine, qualitative analysis for. . . 200 Iodine reactions with alkaloids. . . 42 lodophenin 187 Iron-bluing tannins 466 Iron-greening tannins 466 Isobutyl-carboxyl 518 Isobutyric acid (foot-note) 75 Isovalerates(isovalerianates) 519 Isovaleric (isovalerianic) acid .... 518 Itaconic acid 31 Japaconine 18 Japaconitine 18 Jaune N 186 Jervine in color-test with sulphu- ric acid 50 Johnson and Jenkins's method . . . 220 Kairines 167 Kerner's test for quinine, 139, 144, 146 Kjeldahl's method for nitrogen. .. 234 Koffein 77 Kottstorfer's method for fats 254 Kottstorfer's number, interpreta- tion of 304 Lanthopine 360, 362 Lard 390 Lard oil 292 Lard, tests of purity of 291 Laudanine 360, 362 Laudanosine 360, 362 Laudanum assay 385 Laurie acid 345 Laut's violet 188 Lead chromate, for organic analy- sis 203 Lees of tartar 496 Lemon-juice, assay of 89 Leucoline 165 Leucomaines 428 Leukindophenol 188 Lichen- red 192 Liebig's test for quinine 151 Light oil, of coal-tar distillations. . 395 Lignose, in plant analysis. . .418, 420, 426 Lime-juice 85, 89 Linoleic acid 249 Linoxyn 249 Linseed oil 284 Linseed oil, tests of purity of 28 Liquids, organic combustions of.. 213 Liver, excretion of aconite alka- loids in 29 Liver, excretion of morphine in . . 372 Liver, excretion of strychnine in. . 450 Lobeline, in plant analysis 425 Loganin 447 Logwood blue 192 Logwood in inks 482 Lowenthal's method of estimating tannins 468 Luteolin 186 Mace oil, melting of 269, 272, 274 Madder colors 189 Madder-red 193 Madder- violet 194 Magdala-red 182 Magenta 183 Malachite green 187 Malic acid. . . 333 5 28 INDEX. Manchester brown 186 Margaric acid 244. Martin's yellow 185 Mate, assay of , 81 Mauvein 188 Mayer's solution 43 Mean molecular weight of fat acids 261 Meconic acid 337 Meconic acid, as analytical proof of opium 370 Meconidine 360 Meconidine in color-test with sul- phuric acid 50 Meconin 362 Meissl's method for fats 253 Melting and congealing points of fats 265 Menyanthin, in plant analysis. . . 425 Metacresol 394 Metatungstic acid with alkaloids 43 Metaxylenols 394 Methylene blue 187 Methyl-orange 186 Methyl-theobromine 77 Microscopical characteristics of alkaloids 53 Microscopical distinctions of cin- chona alkaloids 101 Microsublimation of alkaloids 53 Middle oil, in coal-tar distillation 395 Midriatic alkaloids 339 Milk, examination of, for salicylic acid 440 Mineral oils, separation from gly- cerides 274 Molecules as final products of chemism 391 Morintannic acid 479 Morintannin 479 Morphine 362 Morphine in color-test with sul- phuric acid 50 Morphine in color-test with Froehde's reagent 51 Morphine, salts of 364, 365 Morphine, tests of purity of 386 Morus tinctoria 479 Murexid 80 > Murexoin 80 Murexoin test for theobromine . . . 513 Muscarine 427 Mygdalein 427 Myristic acid 245 Mytilotoxine 428 Narceine 359, 362 Narceine in color-test with sul- phuric acid 50 Narceine in color-test with nitric acid 52 Narcotine 387 Narcotine in color- test with sul- phuric acid 50 Narcotine in color-test with nitric acid 52 Neuridine .' . 427 Neurine 427, 428 Nitrogen and carbon, relative de- termination 233 Nitrogen estimation 220, 229, 230, 233, 234 Nitrogen, total, in plant analysis. . 411 Nitrosalicylic acids 438 Nutgalls in inks 482 Nutgalls, treated for preparation of tannic acid 477 Nutgall-tannm 474 Nutmeg oil, melting of 269, 272 Nux-vomica, alkaloids 447 Nux-vomica, assay of 450 Oak-bark tannin 478 Oils and fats 23^ Oil of birch 433 Oils, fixed 238 Oils, fixed, in plant analysis. ..418, 424 Oils, volatile, in plant analysis. . .412, 423 Olive oil, tests of purity of 285 Opianic acid 362, 388 Opium alkaloids 358 Opium assay 374 INDEX. 529 Orcein 192 Organic analysis, divisions of. ... 391 Organic matter 391 Orseille 192 Oxalate of calcium, in plant analy- sis 426 Oxygen, direct estimation of. ... 234 Oxymorphine 359 Naphthalene-Carmine 182 Naphthalene, source of benzoic acid 60 Naphthalene- Yellow 185 Nataloin 54 Nitric acid reactions with alka- loids 51 Nitrogen, qualitative analysis for.. 199 Oleic acid 246 Olein 246 Oleomargarin 292 Olive-kernel oil 287 Olive oil 285 Opium alkaloids 358 Opium, assay of 374 Orange II 186 Orange G 186 Oranges, constituent of 85 Otto's process for alkaloids 33 Oxalic acid, separation from fruit juices 336 Oxygen gas, for organic combus- tions 202 Oxylinoleic acid 249 Palmitic acid 244 Palm oil, melting and congealing of 269, 274 Papaverine 359, 362 Papaverine in color-test with sul- phuric acid 50 Papaver sornniferum 358 Paracresol 394 Paraffin, melting and congealing.. 272 Paraffins, separation from glyce- rides 274 Paratartaric acid.. . . 432 Paraxylenol. . 394 Paricine 93 Parsons' & plan for plant analysis. . 408 Pathological tannins 467 Paulinia, constituent of 77 Paytamine 93 Paytine , 92 Peanut oil, melting of 269, 274 Pectous substances, in plant analy- sis 416,420,421, 425 Pekoe 504 Pelosin 58 Pentoic acids 518 Perkin's method for fats 255 Perkin's violet 188 Persian berries 193 Phenol 393 Phenols 394 Phenolsulphuric acid and its salts 405 Phenyl-acrylic acid 69 Phenylene brown 186 Phenylsulphuric acid (foot-note) . . 406 Phenylsulphuric acid in the urine 402 Phlobaphene, in plant analysis. . . 424 Phloridzin in color-tests with sul- phuric acid 50 Phloxin 183 Phosphine 185 Phosphomolybdates . 46 Phosphorus, qualitative analysis for 199 Physalin, in plant analysis 425 Physetoleic acid 246, 250 Physiological tannins 467 Physostigmine in color-test with sulphuric acid 50 Physostigmine in color-test with nitric acid 52 Physostigmine, in plant analysis. . 425 Phytocheinical analysis 407 Picraconitine 18 Picric acid 398 Picric acid with alkaloids 48 Picric acid, in scheme of color an- alysis 185 Picrotoxin, in plant analysis 425 530 INDEX. Pilocarpine, in plant analysis 425 Pineapple essence 75, 76 Piperine, in plant analysis 425 Piperine, saponification of 171 Pitch, a residue of coal-tar distil- lation 395 Piturine 341 Plant analysis 407 Plasters of belladonna, analysis of 353 Platinic chloride with alkaloids. . 49 Poisoning by alkaloids, analyses for 33 Poisoning by atropine, analysis for 354 Poisoning by carbolic acid, analy- sis for 402 Poisoning by morphine, analysis for 370 Poisoning by strychnine, analysis for 458,449 Poisons, ptomaines in analysis for, 427, 429 Ponceau R 184 Poppy oil, drying of 282 Populin in color-tests with sulphu- ric acid 50 Populin, in plant analysis 425 Potash-bulbs 207 Potash solution, for elementary analysis 205 Potassium bismuth iodide 47 Potassium cadmium iodide 47 Potassium diazobenzene 517 Potassium mercuric iodide 42 Printer's ink 483 Protocatechuic acid formed from tannins 466 Protopine 360, 362 Proximate analysis, inorganic and organic 392 Prussian blue 192 Pseudaconine 18 Pseudaconitine 18 Pseudomorphine 359, 362 Pseudoxanthine 428 Ptomaines 426 Puree 186 Purpurin 190 Purpurogallin 431 Putrescine 427 Pyridinetypeof alkaloids. .340, 97, 171 Pyrogallic acid 430 Pyrogallol 430 Pyrogallol formed from tannins . . 466 Pyrogallol-phthalein 183 Pyrolignate of lime 11 Quassin, in plant analysis 425 Quercitannic acid 478 Quercitrin 193 Quinamicine 92 Quinamidine 92 Quinamine 92 Quinicine 91 Quinidamine 92 Quinidine 154 Quinidine salts 155 Quinidine, tests of purity of 156 Quinine 125, 148 Quinine, assay of 139 Quinine bisulphate 127, 129, 149 Quinine hydrates 126, 128, 148 Quinine hydrobromide... 127, 129, 147 Quinine hydrochloride... 127, 129, 147 Quinine oxalate 127, 129 Quinine Pills, assay of 134 Quinine sulphate 126, 129, 139 Quinine tannate 129 Quinine tartrate 127, 129 Quinine, tests of purity of 134 Quinine valerianate 127, 129, 147 Quinoidine 94 Quinoline 165 Quinoline-red 182 Quinoline salts 166 Quinoline type in structure of al- kaloids 97 Quinoline yellow 185 Racemic acid 432 Rancidity of butters 295 Rape oil, melting of fat acids of. . 269 Reagents for alkaloids 42 Red coloring matters 182, 188, 193 Red inks.. .. 482 INDEX. 531 Red oil or anthracene oil 395 Regina purple 188 Reichert's method for fats 253 Reichert's number, interpretation of 302 Remijia barks, constituents of . . . 92 Resinoils 280 Resins, in plant analysis . . . .418, 424 Resins, separation from glycerides 274 Rhodidine 183 Rhoeadine 360 Rhoeagenine 360 Ricinoleic acid 248 Roccellin 184 Rochleder's method of plant an- alysis 407 Rosaniline blue 187 Rosaniline salts 183 Rosin oils 280 Rosin, separation from soaps. . . . 274 Rotatory power of cinchona alka- loids 121 Ruffle's method for nitrogen 233 Sabadilline in color-test with sul- phuric acid 50 Sabadilline in color-test with nitric acid 52 Sabadilline, in plant analysis 425 Sabatrine, in plant analysis 425 Safflower 189 Safflower-red 191 Saffranin class of colors 183 Saff ranisol 183 Saffron-carmine 193 Salicin in color-tests with sulphu- ric acid 50 Salicin in color-tests with Froehde's reagent 51 Salicin, in plant analysis 425 Salicylates 437 Salicylic acid 433 Salicylic acid, tests of purity of. . 442 Salicyl-sulphonic acid 439 Salicyluric acid 445 Sandal 189, 191 Santonin, in plant analysis 425 Saponification coefficients 257 Saponin, in plant analysis 425 Saprine 427 Sarsaparillin in color-tests with sulphuric acid 50 Schiff's azotometer 221 Senegin in color-test with sulphu- ric acid 50 Senegin, in plant analysis 425 Separators, for alkaloidal solu- tions (illustrated) 35 Sesame oil, melting of 269, 274 " Shaking out" of alkaloidal solu- tions 33 Simpson's method for combustions 227 Sinking point 265 Smilacin in color-test with sulphu- ric acid 50 Socaloin 54 Soda-lime, for organic analysis . . . 204 Soda-lime process for nitrogen . . . 230 Soft pitch 395 Solanaceae, alkaloids of 339 Solanidin, in plant analysis 424 Solanine in color-test with sul- phuric acid 50 Solaniue, in plant analysis 425 Souchong 504 Sparteine, in plant analysis 425 Specific gravity of fats 261 Specific-gravity tests for butters. . 305 Stains of ink, discharge of 484 Starch, in plant analysis . .417, 420, 426 Starch isorners, in plant analysis . . 421 Stas's process for alkaloids 33 Stearic acid 240 Stearic and palmitic acid, melting points of 267, 272 Stearin 240, 243 Sterculia acuminata 513 Storax, constituents of 71 Strammonium, alkaloids of 340 Strychnine 447 Strvchnine salts 443 INDEX. Strychnine separation from bru- cine 458 Strychnos alkaloids 448 Styracin 71 Subliming Cell for alkaloids 53 Sucrose, in plant analysis. . .415, 419, 425 Sugars, in plant analysis.. 415, 419, 425 Sulphocarbolates 405 Sulphophenates 406 Sulphur, estimation of 236 Sulphuric acid reactions with al- kaloids 50, 52 Sulphuric-acid reactions with glu- cosides 50 Sulphur, qualitative analysis for.. 199 Sumach tannin 477 Sunflower-seed oil, melting of fat acids of 269 Syringin in color-test with sul- phuric acid 50 Syringin, in plant analysis 425 Tallow oil 292 Tannic acid 474 Tannic acid reactions with alka- loids 48 Tannic acids (Tannins) 465 Tannic acids in color-tests with sulphuric acid 50 Tanning materials 466 Tannin of hemlock bark 481 Tannin of hops 481 Tannin of tea 480, 504, 506, 510 Tannins 465 Tannins, estimation of 468 Tannins, in plant analysis 415, 424 Tar oils, estimation in crude car- bolic acid 403 Tartaric acid 485 Tartaric-acid estimation 489 Tartaric acid, inactive 432 Tartaric acid separation from fruit juices 336 Tartars 496 Tartrate of calcium 498 Tartrates 486 Taxine, in plant analysis 425 Tea, assay of .' . . . 81 Tea infusions 509 Teas, black and green 504 Teas of commerce 504 Tea, tannin of 480, 534 6 Thalleioquin 130 Thalline 163 Thea plant 504 Thcbaiue 358, 302 Thebaine in color-test with sul- phuric acid 50 Thebaicine 359 Thebenine 359 Theine 77 Theobroma cacao 512 Theobromine 512 Thiosulphate method for nitrogen 233 Toluene, source of benzoic acid. . 60 Toluylene-red 183 Toxicology of aconite alkaloids.. 28, 24 Toxicology of alkaloids in general 33,42 Toxicology of atropine 354, 345 Toxicology of belladonna 340, 354 Toxicology of carbolic acid 402 Toxicology of "cheese poison". . . 514 Toxicology of fusel oil 318, 316 Toxicology of morphine 370 Toxicology of ptomaines 427, 429 Toxicology of strychnine 458, 449 Trirnethylamine, in plant analysis 425 Triraethylamine, with ptomaines.. 427 Tropeines ol>9 Tropic acid 339, 349 Tropines 339, 349 Tropceolin 186 Tropo3oline-yellow 186 Turkey-red oil 287 Turmeric 193 Tyrotoxicon 514 Ultimate analysis, inorganic and organic 392 Ultimate organic analysis 201 INDEX. 533 Uric acid, test of 80 Urine, analysis of, for aconitine 28, 29 Urine, analysis of, for atropine . . . 355 Urine, analysis of, for carbolic acid 402 Urine, analysis of, for strychnine 460 Urine, excretion of aconitine in. . 29 Urine, excretion of atropine in ... 346 Urine, excretion of benzoic acid . . 62 Urine, excretion of carbolic acid 402 Urine, excretion of cinnamic acid 70 Urine, excretion of morphine in. . 372 Urine, excretion of quinine 128 Urine, excretion of salicylic acid in 436 Urine, excretion of strychnine in 449 Valerates (valerianates) 519 Valeriana officiualis 518 Valerian root 518 Valeric (valerianic) acids 518 Varentrapp and Will's method. . 230 Veratrine, saponification of 171 Veratrine in color-test with sul- phuric acid 50 Veratrine in color-test with nitric acid 52 Veratroidine in color-test with sulphuric acid 50 Vesuvin 186 Vesuvin-brown 105, 195 Viburnum opulus 519 Victoria-blue 187 Victoria-green 187 Vinegar assay 15 Vinegars 14 Violet coloring matters 188, 194 Viscosity of butter soaps 297 Vitali's test for atropine 347 Volatile oils, in analysis of plants 412, 423 Wagner's method for estimating tannins 473 Walnut oil, drying of 282 W T anklyn's method for nitrogen.. 234 Warren's method of combustions 214 Warrington's estimation of tartar- ic acid 491 Water-blue 187 Water- washed solvents 34 Waxes, in plant analysis 418 Waxes, separation from glycerides 274 Weinsaure 485 Weld 193 Wine, analysis for salicylic acid. . 440 Wintergreen oil 433 Wittstein's plan for plant analysis 407 Wool fat, melting of fat acids of.. 269 Wormwood 7 Writings, chemical examination of 483 Xanthine 77 Xanthine, dimethyl 512 Xanthocreatinine 428 Xanthoxylum, constituent of 72 Xylenols 394 Xy lol-sulphonic acids 406 Yellow and orange coloring matters 1 84 Yellow coloring matters 192 Zimmtsaure, 69 H. 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