POISONING WITH SULPHATES OF ZINC AND IRON. 13 
Hitherto the French have been enabled to produce iodine at a less cost than the 
English manufacturer, arising principally from the great value of chloride of 
potassium in France, the chloride being a secondary product in the manufacture 
of iodine. Recently, however, the Emperor of the French has taken the duty off 
chloride of potassium, and this, together with the late discovery of an island the 
superstratum of which is entirely composed of almost pure chloride of potassium, 
while the strata below consist of chloride of sodium, etc., will seriously affect 
the value of the chloride of potassium produced in the manufacture of iodine. 
Under these circumstances it is generally believed that this important branch of 
industry will be to some extent transferred to this country. Iodine for many 
years past has been a favourite article with wealthy speculators for the invest¬ 
ment of large capital, and it has ranged from 3 \d. to 2s. Sd, per ounce in a few 
months. About two years since it fell to 3 §d. per ounce, which was supposed to 
be owing to the ingenious and economical process of Mr. Stanford. By the old 
process one ton of seaweed would only yield from eight to fourteen pounds of 
iodine. 
Formerly commercial iodine contained a large percentage of moisture, and on 
keeping the iodine for twelve months this loss sometimes amounted to 10 lb. in 
a cwt.,°a great deal of which was absorbed by the staves of the casks or passed 
through them and was lost. The moisture is generally estimated by pressing 
the iodine between folds of blotting-paper, and the appearance of the paper in¬ 
dicates the amount of moisture present. Iodine sometimes contains iodide of 
cyanogen, which rises in fine white needles when the iodine is heated, d his is an 
accidental impurity produced by one of the processes sometimes adopted in the 
manufacture. Iodine has been adulterated to some extent with manganese, 
alumina, sand, etc., although this is not of frequent occurrence. A quantity of 
iodine purchased some weeks since was found, on examination, to contain in 
each keg of 100 lb. 2 lb. of a substance or adulteration which was proved to be 
furnace drift or the substance found in the flues of steam-boilers. This claim was 
not allowed by the seller, owing to the iodine having been approved on inspec¬ 
tion without testing. This may be of some value to buyers of iodine. The 
facility and perfection by which the salts of iodine are produced, their rich and 
varied colours, and striking geometrical form, render them of more than ordi¬ 
nary interest to the chemist; as a few illustrations of this may be mentioned, 
sublimed iodide of arsenic,* so closely resembling the leaf of the seaweed, the 
rich sable plumes of iodide of sulphur,f biniodide of mercury, and the truncated 
crystals of iodide of ammonium. 
POISONING WITH SULPHATES OF ZINC AND IRON. 
TO THE EDITOR OF THE PHARMACEUTICAL JOURNAL. 
Sir —Can the sulphates of zinc and iron be resorted to to effect slow-poisoning ? 
I have been induced to ask myself this question from the chemical examination 
of a case at Malmesbury. From the evidence given at the inquest, it appeared 
that Dr. Salter was called in to the wife of a liorse-doctor, on the 12th Apn 
last, and continued so until the 23rd, for uterine haemorrhage and vomiting. I he 
former complaint was soon cured, but the latter continued so obstma e y anc 
followed so constantly her husband’s supplies of food and drink, that on that 
day, on her coming downstairs, she vomited in Dr. Salter s piesence, anc ie 
* When sublimed in vessels containing air the sublimate will be interspersed with costal- 
line tufts of arsenious acid. 
f This sublimate only contains 3 per cent, of sulphur, according to Rose. 
