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SELECTED ARTICLES. 
pared this distilled water, by pounding the root in a mortar, 
moistening it with half its weight of water, and after twenty- 
four hours distilling it in an apparatus furnished by M. Sou- 
beiran, I have derived from one part of the root four parts 
of limpid distilled water, having a marked odour and a pun- 
gent taste. 
Watery solution. Cold water removes from gentian the 
bitter principle, sugar, gum, a portion of pectic acid, the acid 
principle gentisin, a little oily substance and resin, as well as 
a portion of odorous and volatile matter. Hot water, employ- 
ed in infusion, has an action exactly similar; only the propor- 
tion of resin dissolved is a little more. By decoction, a con- 
siderable amount of pectic acid is removed, as well as resin 
and fatty matter. It can be inferred from these results, that 
hot or cold water is appropriate to dissolve the active parts 
of the gentian, and that it should be employed in the pre- 
paration of the extract and the syrup of gentian. 
Jllcoholic solution. We have seen that strong or weak 
alcohol completely exhausts the gentian root of its bitterness. 
For pharmaceutic usage, custom has limited the strength of 
alcohol to 22*^, which will dissolve, it is true, a large number 
of the principles which are foreign to the bitter substance, 
which is of little importance. The tincture of gentian contains 
bitter matter, sugar, gum, the acid principle gentisin, and 
fatty, resinous, and odorous substances. 
Conclusion. 
The principal results of my researches, have led me to cor- 
rect many ideas which chemists have entertained upon the 
composition of gentian. 
1. Gentianin, which was considered as the bitter principle 
of gentian, contains, on the contrary, but a small proportion of 
the bitterness of the root. It is composed of gentisin, or an 
insipid crystalline substance, and variable proportions of fatty, 
odorous, and bitter matters. 
2. The crystalline substance of gentian, which I call gentisin, 
is a mass destitute of bitterness, in which is found a marked 
