(16) On alkaloids homologous with strychnine, SHENSTONE, 1883-85: Jour. Chem. Soc. 43, 101; 47, 139; Ber. d. chem. Ges., 17, 2849. HANSSEN, 1884-86: 17, 2849; 18, 777, 1917; 19, 520; Jour. Chem. Soc., 48, 276, 819, 1146; 50, 564. BRUNTON, On physiological effects, 1885: Jour. Chem. Soc., 47, 143.

(17) On homologues of cocaine, SKRAUP, 1885: Jour. Chem. Soc., 48, 1249. CALMELS and GossIN, 1885. F. G. Novy, Production of the propyl and butyl derivatives, 1887: Am. Asso. Adv. Sci.

(18) Kekulé, "Constitution of aromatic compounds," 1865: Bull. Soc. Chim., 27, Jan.; Ann. Chem. Phar., 137, 129; "Lehrbuch der organ. Chem.," II. 491-518.

(19) Aromatic constitution of pyridine and quinoline, KÖRNER, 1870. BAEYER, 1870: Liebig's Annalen, 154, June; 155, Sept., Ber. d. chem. Ges., 12, 1320. DEWAR, 1871: Chem. News, 23, 40. Ladenburg's "Handwörterbuch der Chemie," I. 535.

(20) As to the linking of nitrogen in pyridine, RIEDEL, 1883: Ber. d. chem. Ges. 16, 1609; Jour. Chem. Soc., 44, 1152. Further, Ber. d. Chem. Ges., 17, 1521. LADENBURG, ibid, 16, 2063. BERNTHSEN, ibid, 16, 1808.

(21) On the origin of pyridine, ANDERSON: Phil. Mag. (4) 2, 257; Ann. Chem. Phar., 80, 55; Jahr. d. Chem., 1851, 478. (22). WILLIAMS: Chem. Gazette, 1855, Nov. 1. (23). PERKIN: Jour. Chem. Soc., 17, 9. Further on the synthesis of pyridine and its derivatives, 1886: STOKES and v. PECHMANN, Am. Chem. Jour., 8, 376.

(24) On the origin of quinoline, GERHARDT: Ann. Chem. Phar., 42, 10; 44, 279. HOOGEWERFF and v. Dorp. SKRAUP: Monat. f. Chem., 1, 317, 2, 141. Literature of quinoline derivatives, in sixty-four pages condensed, Ladendurg's "Handwörterbuch," 1884, p. 532.

(25) The saponification of atropine, PFEIFFER, 1863: Ann. Chem. Phar., 128, 273. KRAUT, 1863: Ann. Chem. Phar., 128, 280; 133, 87. LOSSEN, 1864-8: Ann. Chem. Phar. 131, 43; 138, 230; 148,

236.

(26) Saponification of aconite alkaloids, C. R. A. WRIght with others, 1877-79: Jour. Chem. Soc., 31, 143, 33, 151, 318; 35, 387, 399; Phar. Jour. Trans., (3)8, 164, 167. MANdelin, 1885: Archiv d. Phar. (3) 26, 97, 129, 161. JUERGENS, 1885: Phar. Zeitsch. Russland.

(27) Saponification of cocaine, LOSSEN, 1865: "Dissertation." WÖHLER and LOSSEN,1865: Ann. Chem. Phar., 121, 374; 133, 352. (28). Decomposition products of narcotine, WRIGHT, 1876-7: Jour. Chem. Soc., 29, 461; 28, 573; 32, 525.

(29) Products of veratrin (cevadin), WRIGHT and Luff, 1878: Jour. Chem. Soc., 33, 338.

(30) Saponification of piperine, BABO and KELLER, 1857: Jour. prakt. Chem., 72, 53. STRECKER, 1858: Ann. Chem. Phar., 105,

317. Piperidine by dry distillation, WERTHEIM, 1849: Ann. Chem. Phar., 70, 58. CAHOURS, 1853: Ann. Chem. (3) 38, 76.

(31) Synthesis of atropine from saponification products, LADENBURG, 1879-82: Ber. d. chem. Ges., 12, 941; 13, 104, 2041; 15, 1028.

(32) Formation of cocaine from its decomposition products, Z. H. SKRAUP, 1885: Monatsch. Chem., 6, 556; Jour. Chem. Soc., 48, 1249. W. MERCK, 1885: Ber. d. chem. Ges., 18, 1594.

(33) Derivation of tropine from pyridine, LADENBURG, 188185: Ber. d. chem. Ges., 14, 227, 1342; 16, 1408; 18, 1587, 2967; Ann. Chem. Phar., 217, 74; Jour. Chem. Soc., 44, 670; 46, 760; 48, 565, 992.

(34) Constitution of piperidine, HOFMANN, 1879: Ber. d. chem. Ges., 12, 984. LADENBURG and RотH, 1884: Ber. d. chem. Ges., 17, 513; Jour. Chem. Soc., 46, 1202.

(35) Constitution of nicotine, WISCHNEGRADSKY, 1880: Ber. d. chem. Ges., 13, 2315.

(36) Constitution of conine, HOFMANN, 1881: Ber. d. chem. Ges., 14, 705. As a secondary amine, v. PLANTA and KEkulé, 1854: Ann. Chem. Phar., 89, 129. LADENBURG, 1887: Ber. d. chem. Ges., 19, 439.

(37) Constitution of cinchona alkaloids, WISCHNEGRADSKY, 1881: Bull. Soc. Chim. (2) 34, 334; Jour. Chem. Soc., 40, 444. KÖNIGS with others, 1883-5: Ber. d. chem. Ges., 16, 727; Jour. Chem. Soc., 44, 1143. MICHAEL, 1885: Am. Chem. Jour., 7, 182. (38) On position in the structure of pyridine, LADENBURG, 1885: Ber. d. chem. Ges., 18, 2967; Jour. Chem. Soc., 50, 158. Of quinoline, KNORR and ANTRICK, 1884. FISCHER, TRESSIDOR, 1884-5. Summary, 1885: KEISER, Am. Chem. Jour., 7, 200.

(39) Formation of hydrogen addition products, Ladenburg, 1884: Ber. d. chem. Ges., 17, 156.

(40) The origin of azo compounds, MITSCHERLICH, 1834: Ann. Chem. Phar., 12, 311. A. W. HOFMANN, 1860: Ann. Chem. Phar., 115, 362.

(41) The origin of diazo compounds, GRIESS, 1858-66: Ann. Chem. Phar., 106, 123; 113, 201; 121, 237; 137, 39.

(42) Theory of azo and diazo compounds, Kekulé's "Lehrbuch der organ. Chem.," 1866, II. 688, 703. Ladenburg's "Handwörterbuch," 1884, I. 116 (Heumann); II. 192 (O. Jacobsen).

(43) Tyrotoxicon, VAUGHAN, 1884-6: Zeitsch. f. Physiolog. Chem., 10, 146; Jour. Analyt. Chem., 1, 24.

(44) Jour. Analyt. Chem., 1, 281.

PAPERS READ.

ON THE CONSTITUENTS OF WILD CHERRY BARK (PRUNUS SEROTINA, EHRHART). BY FREDERICK B. POWER and HENRY WEIMAR, Madison, Wis.

[ABSTRACT.]

THE bark of the wild cherry (Prunus serotina Ehrhart, P. virginiana Miller, Cerasus serotina Loiseleur) appears to have been first examined chemically by Stephen Procter1 who inferred the constituents to be: "starch, resin, tannin, gallic acid, fatty matter, lignin, red coloring matter, volatile oil, hydrocyanic acid, salts of lime and potassa, and iron." The hydrocyanic acid was well identified by Procter, and the volatile oil was observed to be "extremely analogous in its properties to the essential oil of bitter almonds."

The next investigation of this subject was by William Procter, Jr., who proved that the volatile oil and hydrocyanic acid do not preëxist in the bark, but are formed from a principle "which acts as amygdalin, and a decomposing agent which, like emulsin, is rendered inert by ebullition."

It was formerly supposed that the bark also contained phlorizin, but this principle could not be found therein by Mr. Perot,3 and the editors of the U. S. Dispensatory, xv edition, p. 1194, therefore express the opinion that "the tonic property must reside either in the portion of amygdalin which may remain undecomposed, in the pure volatile oil resulting from its reaction with water, or in some yet undiscovered principle." The correctness of these inferences the editors state, loc. cit., would seem to be proved by an experiment of Professor Procter, "who found the bitterness of an extract of the bark to remain after it had been wholly deprived of amygdalin."

From the time the above mentioned investigations were made to the present day most of the commentaries and text-books on materia medica have continued to make the unqualified statement that wild cherry bark contains amygdalin and emulsin, notwithstanding the fact, as a perusal of the original papers referred to will show, that neither of these substances has as yet actually been isolated from this source.

It might, indeed, seem reasonable to conclude that, since wild cherry bark, in contact with water, affords benzaldehyde (bitter almond oil) and hydrocyanic acid, these bodies must be formed from principles identical 1 Amer. Journ. Pharm., 1834, Vol. VI, p. 8. 2 Ibid. 1838, Vol. X, p. 197. Ibid. 1852, Vol. XXIV, p. 111.

with those contained in the bitter almond, which, as is well known, have already been isolated, and their chemical and physical characters definitely and accurately established.

This inference, however, is not necessarily correct, since Ritthausen and Kreusler have shown that vetch seeds afford benzaldehyde and hydrocyanic acid, although they do not contain amygdalin; and a still more interesting example from the animal kingdom is presented by a myriapod belonging to the genus Fontaria, which, when irritated, diffuses the odor of hydrocyanic acid, and, upon distillation with water, affords the latter substance, together with benzaldehyde. The substance which, in this instance, by the action of a ferment, affords these principles cannot be identical with amygdalin, since it is soluble in ether. It has also been proved that cherrylaurel leaves do not contain crystallizable amygdalin, although upon distillation with water they afford products analogous to those of the bitter almond.6

The conclusion that wild cherry bark contains amygdalin' appears moreover, independent of its botanical relationship with the bitter almond, to be based entirely upon the fact that Procter, by appropriate treatment, obtained a colorless aqueous solution, which, in contact with emulsin, developed hydrocyanic acid and benzaldehyde.

In the "Pharmacographia,” second edition, p. 254, in connection with the subject of wild cherry bark, the authors make the more reserved statement that "the bitterness and odor of the fresh bark depend no doubt on the presence of a substance analogous to amygdalin, which has not yet been examined."

It was, therefore, with an endeavor to ascertain whether crystallizable amygdalin was contained in, or could be isolated from, wild cherry bark, as also to obtain some further information regarding the supposed distinct bitter principle, that the following preliminary investigation was undertaken.

1. Examination for Amygdalin.

One kilogram of the bark, in No. 40 powder, was digested with 95 per cent alcohol for half an hour on a water bath. The liquid was then filtered and the residue treated repeatedly in this manner until the filtrate was nearly colorless. This liquid was then distilled until two-thirds of the alcohol was recovered. The residue had a very dark color and a strongly astringent taste, due to the tannic acid. In order to remove the latter the liquid was digested with oxide of lead, subsequently allowed to dry with the latter on a water-bath, and afterward extracted with strong alcohol.

Flückiger's Pharmakognosie, second edit., p. 954 and Jahresbericht der Chemie, 1870, p. 883.

Flückiger, loc. cit. p. 955 and Ber. d. deutsch. Chem. Ges. 1883, p. 92.
Jahresbericht der Pharm., etc., 1874, p. 197.

7 Our references to amygdalin in this paper will be understood as referring to pure, cry stallizable principle, CH27NO11 which may so easily be obtained from the bitter almond by the process of Liebig & Wöhler.