336 SELECTED ARTICLES. 
which has a very great resemblance to that obtained by alco- 
hol at 40° 
Alcohol at 30° dissolves very nearly the same principles, 
but the extract is then much charged with resin, which is 
with difficulty separated from the yellow crystals, and which 
renders their extraction very difficult. 
All these alcoholic extracts, taken up by water, give nearly 
the same products. Water removes the bitter extract, the 
sugar and acid, and leaves the fixed oil under the form of 
white flocculi, and the yellow crystals united with a little 
resin. It is easy to isolate these last products, by treating 
them with boiling alcohol at 30°, which dissolves the gen- 
tianin, the resin, and a very small quantity of oil, which can 
finally be removed by a little cold ether. Cold alcohol at 40°, 
however, affords crystals less charged with resin, and more 
easily purified. 
Water, by the first maceration, removes from gentian all 
its colour, and a great part of its bitterness. It dissolves, in 
a great measure, the pectin which gelatinises at the end of a 
certain time. Having acted, by means of ether and alcohol, 
upon gentian exhausted by water, I was not able to obtain 
gentianin from it, which led me to think that it is removed by 
the water, in despite of its little solubility in this vehicle, and 
doubtless favoured by the other princples contained in the 
root, which facilitated solution. 
Water, holding an alkali in solution, removed still more 
promptly the colour and bitterness of gentian. When acidu- 
lated, nothing of consequence resulted. 
Gentian, exhausted by alcohol, is completely deprived of its 
bitter portion. There is nothing, except ether, when it is 
very pure, w^hich is not charged with it; or, to speak more 
rigidly, does not take up traces of it. 
Of Gentianin. 
The name gentianin, given by MM. Henry & Caventou to 
the yellow crystallizable substance, conveys the idea that this 
substance is the cause of bitterness in gentian, and the prin- 
ciple of its action upon the animal economy. 
