IRON. 
§ 920 .] 
715 
those produced by the chloride. There are usually colic, vomiting, and 
purging ; but in one case (reported by Chevallier), in which a man gave 
a large dose of sulphate of iron to his wife, there was neither vomiting 
nor colic ; the woman lost her appetite, but slowly recovered. Probably 
the action of ferrous sulphate, like that of the chloride, is profoundly 
modified by the presence or absence of food in the stomach. Anything 
like 28-3 grms. (an ounce) of sulphate of iron must be considered a 
dangerous dose, for, though recovery has taken place from this quantity, 
the symptoms have been of a violent kind. 
§ 920. Search for Iron Salts in the Contents of the Stomach, etc. 
—Iron being a natural component of the body, care must be taken not 
to confound the iron of theblood or tissues with the “ iron ” of a soluble 
salt. Orfila attempted to distinguish between the two kinds of iron by 
treating the contents of the stomach, the intestines, and even the tissues, 
with cold acetic acid, and allowing them to digest in it for many hours 
before filtering and testing for iron in the filtrate, and this is generally 
the process which has been adopted. The acid filtrate is first treated 
with sulphuretted hydrogen, which gives no precipitate with iron, and 
then with sulphide of ammonium, which precipitates iron black. The 
iron sulphide may be dissolved by a little hydrochloric acid and a drop 
of nitric acid, and further identified by its forming Prussian blue when 
tested by ferrocyanide of potash, or by the bulky precipitate of oxide, 
when the acid liquid is alkalised by ammonia. In the case of Duf-, 
the experts attempted to prove the existence of foreign iron in the liver 
by taking 100 grms. of Duf-’s liver and 100 grms. of the liver of a 
non-poisoned person, and destroying each by nitro-muriatic acid, and 
estimating in each acid solution the ferric oxide. Duf-’s liver yielded 
in 100 parts -08 mgrm. of ferric oxide, the normal liver -022—nearly 
three times less than Duf-’s. 
To obtain iron from the urine, the fluid must be evaporated down to 
a syrup in a platinum dish, a little nitric acid added, heated, and finally 
completely carbonised. The residue is dissolved in hydrochloric acid. 
Normal urine always contains an unweighable trace of iron ; and there¬ 
fore any quantity, such as a mgrm. of ferric oxide, obtained by careful 
precipitation of the hydrochloric acid solution out of 200 to 300 c.c. of 
urine, would be good evidence that a soluble salt of iron had been taken. 
The hydrochloric acid solution is first precipitated by ammonia and 
ammonic sulphide. The. precipitate thus obtained, will not be pure 
iron sulphide, but mixed with the earth phosphates. It should be 
redissolved in HC1, precipitated by sodic carbonate, then acidified by 
acetic acid and sodic acetate added, and the solution well boiled ; the 
iron will then be precipitated for the most part as oxide mixed with a 
little phosphate of iron. 
Since, as before mentioned, a great portion of the iron swallowed as a 
