350 Miscellanies. 
genous plant as the powerful succedaneum of quinquina and the sul- 
phate of quinine. Several of them agree in considering the holly 
as superior to quinquina. Dr. Rousseau deserves great credit in 
bringing the virtues of this plant so fully into notice. He has suc- 
ceeded in obtaining its active principle in an isolated form, and has 
given it the name of Jlicine.—Rev. Encyc. Sept. 1831. 
2. Fertilizing property of Sulphate of Lime.—In order to de- 
termine the manner by which Plaster of Paris contributes to vegetable 
growth, M. Peschier, a pharmaceutist of Geneva, performed several 
comparative experiments.. Two theories have been suggested by 
chemists—one, that the plaster acts simply as a stimulus to the organs 
of the plant—the other, that it gives up to the plants its water of crys- 
tallization. M. Peschier filled two vessels with siliceous sand slightly 
moistened, and sowed in each of them a few seeds of water cresses 
and watered one of them with pure water and the other with a solu-. 
tion of sulphate of lime. The piants, when a few inches high were 
burned, and equal quantities of their ashes were analyzed. In those 
watered with the solution of sulphate of lime, there was found a much 
more considerable quantity of sulphate of potash than in the other. 
In a second experiment he found that the proportion of sulphate 
of potash was increased when the plants watered with the solution 
of sulphate of lime, were subjected to the action of a galvanic 
current. 
M. Peschier thence infers that the plaster undergoes a decompo- 
sition by the act of vegetation, and he thinks he has observed that 
crude plaster is more efficacious than that which has been calcined. 
Rev. Encyc. Nov. 1831. 
3. Composition of Gum.—M. Guerin read to the French Academy 
a memoir on Gum, in which he maintains, that no substance is a gum 
but that which, when treated with nitric acid, produces mucic acid. 
He shows that this property depends on two immediate principles, one 
of which is always present in gum and more frequently both togeth- _ 
er, though in very unequal proportions. One of these principles is 
arabine, the soluble portion; the other bassorine, insoluble. He di- 
vides all gums into two great families dependent on the predominance 
of one or the other of these principles. The memoir contains an 
analysis of the different gums, showing the preportion of these ele- 
ments in each.—Idem. 
