QUANTITATIVE ESTIMATION OF THE ALKALOIDS. 73 
the chloroform is boiled off to dryness in a water-bath, when the 
alkaloids will be left in warty groups of radiating crystals, adhering 
over the bottom and sides of the flask. The flask is then placed 
on its side in a drying-oven, and dried at 100° C. (212° F.) to a 
constant weight. The weight of the contents multiplied by 20 
gives the percentage of the total alkaloids of the cinchona in an 
anhydrous condition, to within 0.1 to 0.2 per cent., if the process 
has been well managed.” | 
If it is desired to avoid the use of ether, the alkaloids liberated 
by lime may be taken up by xylol, toluol, or amylic alcohol at the 
boiling temperature, and subsequently abstracted from these so- 
_ lutions by means of dilute acids. 
Estimation of Quinine. 
“Into the flask containing the total alkaloids, after these have 
been weighed, are placed 5 grams (78 grains) of glass, which has 
been ground up in a mortar to a mixture of coarse and fine pow- 
der, and 5 cubic centimeters (80 minims) of stronger ether added. 
The flask is then corked, and shaken vigorously until, by means of 
the glass, all the alkaloids have been detached from the flask and 
ground up, in the presence of the ether, into fine particles. In this 
way the definite quantity of ether which is large enough to dissolve 
all the quinine that could possibly be present becomes entirely 
saturated with alkaloids, in the proportion of their solubility, and 
the solution will necessarily embrace all the very soluble ones as 
the quinine. 
“Two test-tubes are now marked at the capacity of 10 cubic cen- 
timeters (160 minims) each, and a funnel and filter of 7 centime- 
ters (2.8 inches) diameter placed over one of them. The filter is 
well wetted with ether, and the mixture of alkaloids, ether and 
glass poured on to it from the flask. The flask is rinsed out two 
or three times on to the filter with fresh ether, the filter then washed, 
and the glass percolated with fresh ether, applied drop by drop 
from a pipette, until the liquid in the test-tube reaches the 10 
cubic centimeter (160 minim) mark. The funnel is then changed 
to the other test-tube, and the washing and percolation with ether 
continued until the mark on the second test-tube is reached by the 
filtrate. The contents of the two test-tubes are poured into two 
small tared capsules, evaporated to a constant weight and weighed. © 
The first capsule will contain what may be called the ether-soluble 
alkaloids, and if from the weight of these the weight of the residue 
in the second capsule be subtracted, the remainder will be the 
approximate weight of the quinine extracted from the 5 grams of 20 
F 
