Prunus serotina, Ehrhart. (Prunus virginiana, Miller.)
The stem-bark collected in autumn and carefully dried.
Syn. Prun. Virg., Wild Black Cherry Bark, Cabinet (Rum, Whisky, Black-choke, Wild) Cherry; Br. Pruni Virginianae Cortex, Virginian Prune Bark; Fr. Ecorce de Cerisier de Virginie; Ger. Wildkirschenrinde.
Pru'nus. L. fr.
Vir-gin-i-a'na. L. of, or belonging to Virginia - i. e., Virginian.
Plant. - Large tree 9-24 M. (30-80°) high; trunk regular, straight, with blackish, rugged outside bark, that of young branches smooth, red or purplish; leaves 5-12.5 Cm. (2-5') long, oval, petiolate, serrate, teeth glandular, glabrous, shining, bright green, with 2 small glands on the margin at the base; flowers May-June, appearing after the leaves, small, white, racemes; fruit August, drupe, size of a pea, purplish-black, pulpy, sweet, acidulous, slightly astringent and bitter - bitter cherries; seed subglobular, bitter almond flavor, containing bland, yellowish-green fixed oil 25 p. c. Bark, usually in tranversely curved pieces, 2.5-8 Cm. (1-3 1/5') long, 12-25 Mm. (1/2-1') broad, .5-4 Mm.
1/50-1/6') thick, light brown, greenish-brown, smooth, except numerous lenticels, 3-4 Mm. (1/8-1/6') long; inner surface light brown, longitudinally striate, occasionally fissured, fracture short, granular; odor distinct, hitter, almond-like when macerated in water; taste astringent, aromatic, agreeably bitter. Powder, light brown; microscopically - bast-fibres, stone cells, crystal fibres, rosette aggregates of calcium oxalate, starch grains, .003-.004 Mm. (1/8325-1/6250') broad. Young, thin bark best, and that from very large or small branches should be rejected. Should be kept dark, in tightly-closed containers. Solvents: hot or cold water. Dose, 3ss-l (2-4 Gm.).
Adulterations. - Unrossed bark, that of old stems, also that of choke cherry, which closely resembles the official, but as a rule is either thinner or thicker, and breaks with a very tough fracture like slippery elm.
Commercial. - The Latin official name, from its long usage, has been retained, although misleading; Prunus virginiana was given early by Linnaeus to Choke Cherry, a shrub 2.5-3 M. (8-10°) high, having more sharply toothed leaves, shorter racemes, and astringent, dark red, crimson fruit, size of wild cherry. It has received various names at different times, as Prunus ru'bra, P. obova'ta, P. virginiana, P. serotina, Cerasus serotina, C. virginiana. The true official Prunus serotina grows in fertile soil in fields, woods, along fences, seldom in clusters; wood is valuable for furniture, being hard, red, fine-grained, and easily polished. Bark after collection is (rossed) deprived of outside layer (periderm or ross), exposing green phelloderm, and then dried; while that from all portions of the tree is used, that from the root is strongest, yet it all soon deteriorates, consequently only the fresh-dried should be employed; the average bark collected in April yields most starch, but least tannin, and hydrocyanic acid - .0478 p. c; in June - .0956 p. c; in Oct. - .1436 p. c. or 1/7 gr. (.009 Gm.) from 100 gr. (6.5 Gm.) bark, which equals 7-8 m (.5 Ml. (Cc.)) of official acid; young bark may yield of acid .183-.250 p. c, old bark .159-.335 p. c.
Amygdalin. - Glucoside, obtained by the action of alcohol; it is bitter, non-crystalline, and not precipitated by ether, hence in this differs from that in bitter almond.
Emulsin. - Ferment, extracted by water; white powder when pure, and by its action on amygdalin, in the presence of water, develops hydrocyanic acid and the volatile oil of bitter almond, neither of which, as such, existed previously in the bark. These two are obtained also by distilling the seeds with water, when they come over more or
Fig. 167. - Prunus serotina.
less mixed. The poisonous property of the oil depends largely upon the amount of acid present, and when freed of this, the oil becomes a bland, colorless liquid resembling that from bitter almond. Some think the ferment to be neither emulsin nor synaptase, but a closely analogous compound.
Bitter Principle. - Obtained by mixing soft aqueous extract with alcohol, shaking with milk of lime, evaporating filtrate, boiling residue with alcohol, evaporating, getting brown, bitter, gelatinous mass, which is insoluble in ether, soluble in alcohol, brownish-red with sulphuric acid.
Preparations. - 1. Syrupus Pruni Virginianae. Syrup of Wild Cherry. (Syn., Syr. Prun. Virg.; Br. Syrup of Virginian Prune; Fr. Sirop d'Ecorce de Cerisier; Ger. Wildkirschenrindensirup.)
Manufacture: 15 p. c. Mix glycerin 5 Ml. (Cc.) with water 20 Ml. (Cc.), moisten wild cherry bark 15 Gm. with 10 Ml. (Cc.) of mixture, pack in percolator, add remainder of mixture, and enough water to saturate and leave stratum above, macerate for 24 hours, percolate with water q. s. 50 Ml. (Cc.), add sugar 80 Gm., dissolve by agitation, strain, pass through strainer water q. s. 100 Ml. (Cc.); mix thoroughly. Should be kept cool, in non-metallic, tightly-closed containers, as it rapidly loses hydrocyanic acid under most favorable conditions. Dose, 3j-4 (4-15 Ml. (Cc.)); mainly for flavoring.
Unoff. Preps.: Fluidextract (glycerin 20, alcohol 20, water 60, finishing with 20 p. c. alcohol), dose, 3ss-l (2-4 Ml. (Cc.)). Infusion,
4 p. c., dose, ℥ss-2 (15-60 Ml. (Cc.)). Tinctura Pruni Virginianae (Br.), 20 p. c + alcohol 62.5 p. c, finally add glycerin 10 p. c, dose, 3ss 1 (2-4 Ml. (Cc.)).
Properties. - Sedative, pectoral, aromatic bitter tonic, astringent; increases appetite, digestion. Volatile oil - local stimulant on alimentary canal like cas-carilla, serpentaria, etc. Hydrocyanic acid - sedative, nervine, large doses decrease heart action. Tannin is astringent.
Uses. - Consumption, cough, bronchitis, scrofula, heart palpitation, stomach atony, dyspepsia, hectic fever, debility; cold infusion in ophthalmia. It is much inferior to cinchona in inter-mittents.