232 
SELECTED ARTICLES. 
distilled water was poured on until the entire quantity of the 
iodide of zinc was carried through. The washings were con- 
centrated, suffered to cool, and then treated with the equiva- 
lent quantity of nitrate of silver, and the resulting precipitate 
(iodide of silver) having been, as in the previous experiment, 
sparingly washed with cold water, containing a little ammo- 
nia, was dried and weighed. From this the total quantity of 
iodine in the compound, both that combined with the potas- 
sium and with the oil was collected. But the quantity in the 
former state having been already ascertained, the difference is 
the quantity of iodine associated with the oil. 
In an experiment thus conducted, 6.55 grains of the sub- 
stance yielded, of iodide of silver, 4.52 grains, equivalent to 
37.20 grains of iodine for 100 of the compound. Subtracting 
from this 9.58, the iodine of the iodide of potassium, we ob- 
tain, as the representati ve of the amount of this element asso- 
28.66+27.62 
ciated with the oil, the number 27.62. Hence 
tit 
= 28.14, is the mean amount of the iodine in the latter state 
of combination, as derivable from both experiments. But 
28 14 
— ! — =2.93, or 9.6 = 3. We thus arrive at the conclusion 
9.58 
that for every atom of iodide of potassium in the substance 
tinder consideration, there are three atoms of iodine in combi- 
nation with the oil of cinnamon. 
Before leaving this branch of the analysis, I may observe 
that the iodine of the oil may be directly obtained by decom- 
posing the compound in a glass tube, at a red heat, in contact 
with lime, and acting upon the residue with water, which 
dissolves the iodide of calcium, and along with it a little lime. 
The latter being separated in the usual manner by carbonic 
acid and boiling, the former may be precipitated by oxalate 
of ammonia, and the iodine estimated from the amount of 
carbonate of lime afforded by the oxalate when calcined at an 
sobscure red heat. 
The experiment made upon this plan did not give a very 
satisfactory result; and, when I considered the great dispro- 
