th Re Ue ater oe ee Fen ron ne gisege 
10 ORD. II. Amentacezx. SALIX ALBA. 
tion is of a reddish colour; sulphate of iron produces a dark green precipi- 
tate; asolution of isinglass throws down a precipitate, at first blue, but 
changing to a buff colour; carbonate of ammonia, and potass, and also lime 
water, throw down precipitates of the same colour. The watery extract has 
a bitter taste, is somewhat brittle, ofa reddish colour, and does not deliquesce. 
The alcoholic tincture is of a greenish yellow colour, and is rendered turbid 
by the addition of water; when evaporated, it leaves a bright yellow ex- 
tract, which melts at a moderate heat, and emits an aromatic odour.* Hence 
it appears, that the constituents of the white willow bark are, extractive, bit- 
ter resin, gluten, and tannin: 
. A. Buchner of Munich+ has lately discovered a bitter principle in the 
barks of the salix incana and vitellina, to which he has given the name of 
salicine. This substance, we are told by him, belongs to the class of alka- 
loids, and it is to this principle M. A. Buchner attributes the febrifuge pro- 
perties of the different species of willow. To obtain this principle, he treated 
«1 ry | aS he BEETLE | aay | + PS hi 1 4} 4 = 2 ie 
7 
exhausted it with water acidulated with sulphuric acid: this produced him 
a very bitter solution. He then precipitated the sulphuric acid and the co- 
louring matter, by acetate of lead ; and afterwards separated the excess of 
lead from the liquor, by means of the hydro-sulphuric acid. The liquor was 
then treated with the whites of eggs, and animal charcoal (ivory black), to 
separate the remaining colouring matter: by these means he obtained a very 
bitter solution, nearly colourless. Having boiled the liquor with caustic am- 
monia, he volatilized the acetic acid; during which the liquor took a yel- 
lowish tinge, the evaporation was continued until he obtained a soft extract, 
intermixed with crystals of salicine. Ina second mémoire on the prepara- 
tion and properties of salicine.t M. Buchner gives the preference to the 
following mode of preparing this substance :—viz. dissolve four parts of the 
extract of the bark of common willow] in 24 to 30 parts of water; and add 
* Ann. de*Chimie, liv. 290. 
+ Vide Extrait du Recueil de Pharmacie, rédigé par M. Buchner 4 Munich. Jour- 
nal de Pharmacie, No. X. 15iéme Année, Octobre 1809. 
{ Vide Mémoire sur la préparation et les propriétés de la salicine, par A. Buchner. 
Journal de Pharmacie, No. IV. 1Giéme Année, Avril 1830. 
|| The particular species is not named, but we have every reason to believe that salicine 
may be obtained from every individual species of the genus salix. 
