Mr. BALLY, assuming it as proved, that cinchonia is the more powerful salifiable base of the two in a medical point of view, considers, therefore, that, in regard to the above barks, chemical analysis justifies the order of their relative value, which had been previously deduced from their medical employment.--_Archives Generales de Medecine._ 66. _Sulphate of Quinia, extracted from the Cinchona Bark, exhausted by Decoction._--Mr. JULIA-FONTENELLE, from the sparing solubility of quinia and cinchonia, suspected that decoctions and aqueous extracts of Peruvian bark contained but little of those vegetable alkalies; whence it would follow, that the residuum, generally rejected as having no febrifuge power, would still contain the greater part of them. This suspicion has been in a great measure verified. The aqueous extract was found to contain but little cinchonia and quinia; while the residuum of decoctions, giving the mean results, furnished two-thirds of the sulphate of quinia, yielded by the same weight of cinchona not acted on by water. As decoctions and aqueous extracts of bark are febrifuge, though containing inconsiderable quantities of quinia, and cinchonia, Mr. JULIA-FONTENELLE is led to believe, that these salifiable bases are not the only febrifuge principles in Peruvian bark, but that the extractive matter also possesses that property. His results present a striking difference between alcoholic and aqueous extracts of bark; for while the former contain nearly the whole of the salifiable principles, the latter contain very little.--_Revue Medicale._ 67. _Analysis of Rhubarb._--It is some time since Mr. NANI, an Italian chemist, announced the discovery of a crystallizable vegetable alkali in rhubarb. Mr. CAVENTOU has repeated the experiments of Mr. N. and finds them, in many respects, inaccurate. Upon analysing the alcoholic extract of rhubarb, by the aid of alcohol and ether, employed separately and combined, Mr. C. obtained a fatty matter, containing a little odoriferous volatile oil, and a yellow colouring principle, capable of crystallization, and of being sublimed without decomposition, which may be called _rhubarbin_. He also detected in the alcoholic extract, a brown substance, insoluble in water when pure, but rendered soluble by combination with rhubarbin; when it forms a compound, constituting the _eaphopicrite_ of some chemists, and the _rhubarbin_ of Psaff.--_Archives Generales._ Mr. GEORGE W. CARPENTER, of this city, prepares the medicinal principle of rhubarb in combination with sulphuric acid, under the name of sulphate of rhubarb, by the following process: