314 French National InstUute* 



those of tobacco, contained the same acrid principle, pro- 

 ceeded to analyse it; but he found only an animal sub- 

 stance, salts with a base of potash, and a bitter substance; 

 IVom which the juice of the belladonna receives its narco* 

 tic properties. 



Under the head Physiology, we shall allude to the expe- 

 riments made by M. Vauquelin, on animals^ with ihi^ 

 juice. 



M. Chevrcul has presented to the class some very exten- 

 sive experiments on vegetable substances. Some have for 

 their objects, the bitter principle produced by the action of 

 the nitric acid on organized bodies which contain azote, 

 and which had already occupied the attention of Messrs. 

 liaussman, Welther, Proust, Fourcroy, and Vauquelin. 



M. Chevreul thiidcs that this bitter principle is composed 

 of nitric acid and a vegetable oily or resinous substance; 

 and he ascribes the property which this substance has ol* 

 detonating, to the decomposition of nitric acid, to the 

 formation of ammoniacal gas, of prussic acid, and oily hy- 

 drogen gas, &€. This agrees partly with the observations 

 of Slessrs. Fourcroy and Vauquelin. 



But along with this bitter principle, a resinous matter 

 and a volatile acid are produced, on which M. Chevreul 

 has made various experiments, and which \\2 regards as dif- 

 fering from the bitter principle only in consequence of ita 

 having a small portion of nitric acid. 



A second inquiry of M. Chevreul has for its object tlie 

 substances formed by the action of the nitric acid on charry 

 or resinous bodies, and which have the property of preci- 

 pitating gelatine. The first observations on this subject 

 were made in England by Mr. Flatchett ; and they in- 

 duced a belief that these substances were analogous to tan- 

 nin. M. Chevreul is of opinion that this is erroneous, 

 and that they differ from each other, not only according 

 to the kind of acid and other substance with vvliicli thev 

 have been prepared, but also according to tlie quantity of 

 4ic;d vvhicli has entered inj;o their coniposition. 



Lastly, pursuing alwi^s the same kind of experiments, 

 M. Chevreul directed ^is attention to the difltrent com- 

 pounds formed by the inaction of the sulphuric acid on 

 canq>hor. All the above •researches obtained the appro- 

 bation of the class, and were ordered to be inserted in the 

 Alt' moires des Savans Et rangers. 



We ouiiht to speak, perhaps, of the supposed discovery 

 made by M. Vinterl, of an earth which he calls andronia, 

 ijul \n which he think? he has found some extraordinary 



properties; 



