40 
SELECTED ARTICLES. 
deposit was observed in the bottle. The flocculent substance 
of which we have spoken, when separated by means of a linen 
strainer, possessed a certain degree of elasticity; it passed 
from a pale gray to a deep brown upon desiccation in the air. 
It contracted by heat, like the azoted matter of Colombo; 
it burned with difficulty, exhaling, along with much smoke, an 
animal odor. This substance, without doubt, appertains to 
the quassia; for the same wine of Chablis as that which formed 
the menstruum, preserved in bottles, in an adjoining cellar, 
with the same exposure, and at the same temperature, remain- 
ed clear and without any deposit. 
A certain analogy of action, if not of composition, is per- 
ceived between the azoted matter of quassia and that of the 
currant, examined by Thenard. Both act as a ferment; there 
exists, however, no sugar in quassia, which is the case with 
the currant. 
Of the formation of Nitre in the Extract of Quassia, after 
its preparation. 
The efflorescence of nitre observed upon goblets of quassia 
wood, and the opinion I had formed as to the part the 
azoted matter performed in the production of this salt, deter- 
mined me to test with the extract, the combined action of air 
and humidity during a certain time, in order to determine 
what influence these two agents possessed over nitrification. 
I, therefore, took an ounce of extract, A, recently prepared, 
of pillular consistence, which I deposited in a china vessel, of 
the capacity of four ounces, and having a cover. This I depo- 
sited in a place constantly dry. 
I then took an equal quantity of the same extract, B, which 
I deposited in a similar vessel, but covered with a piece of 
fine linen, properly secured. This vessel was placed upon a 
table, near to, but out of the direct rays of the sun, and in a 
place where, from evaporation, the air was more or less humid. 
Along side of it, arranged in the same manner, was placed 
an ounce of the extract of gentian, C, which, as is known, 
