376 Transactions. —Chemistry. 
. previously calcined. Morphia and narcotina may be substituted for strychnia 
with like results, other alkaloids I have not tried. Those cited can be 
removed from the absorbent by acids. From the results of numerous experi- 
ments I find that of all the silicates cyanite and andalusite (pure silicates of 
alumina) are the most effective absorbents of such bodies. 
The silicates of the alkaline earths, or alkalies simple or compounded either 
among themselves or with silicate of alumina, —— quite negative to the 
alkaloids named. Wayvellite and anhyd jui-oxide of iron had no absorb- 
ing power for them 
These results hrs that the portion of the clay concerned in the production 
of the phenomenon instanced is silicate of alumina, and I should conceive a 
double silicate* to be formed, in every case hydrous, the anhydrous silicates 
of alumina named passing completely to the hydrous condition when finely 
comminated and moistened with water as J] have previously shown (Trans. 
N.Z. Inst., Vol. IV., p. 380). 
Art. LIV.—On the Proposed Substitution of Acetate for Sulphate of Copper 
in the Manufacture of Iodine. By W.Skry, Analyst to the Geological 
Survey of New Zealand. 
[Read before the Wellington Philosophical Society, 23rd October, 1872.] - 
THE precipitation of iodine from the residual liquors obtained in its manufac- 
ture is at present accomplished by Soubeiran’s method, namely by the addition 
of sulphate of copper thereto, iodide of copper thus forming and precipitating, 
but it is found in practice that the precipitation is so incomplete that a 
notable quantity of iodine remains in solution, necessitating the application of 
after processes for the more complete removal of iodine from such cupreous 
liquors. 
In connection with this I would desire to make it publicly known that 
from certain investigations I have made upon this subject it appears that by a 
slight modification of Soubeiran’s method this loss of iodine may be prevented, 
or so nearly that the necessity of after processes will be avoided. 
The particular agents most active in causing this retention of iodine in the 
liquor are sulphate of copper, free sulphuric acid, and alkaline sulphates and 
chlorides, since they exercise a considerable solvent action upon the iodide of 
copper formed in Soubeiran’s process. 
* Since the communication of this paper I find that silica chemically prepared and 
rendered anhydrous by heat will also absorb strychnia from aqueous solution, clearly 
showing that at any rate single silicates of the alkaloids readily form. 
