ON POISONING BY ARSENIOUS ACID. 
333 
poisonous properties. MM. Nonat, Deville, and Sandras, have 
announced that this compound is poisonous. The experi- 
ments which I have performed leave no doubt on this point. 
I administered to robust dogs, of mean size, 32 grammes of 
dry hydrated peroxide of iron, which I had previously com- 
bined with 11 grammes (20 grs.) of arsenious acid ; the fer- 
ruginous compound did not contain an atom of free arsenious 
acid; it could be boiled with waterwithoutyielding to that liquid 
the least trace of the poison. The animals who took this sub- 
arsenite, had more or less abundant alvine evacuations, and 
soon exhibited all the symptoms of poisoning by arsenic; 
they died in 28, 30 and 40 hours, provided vomiting was 
prevented, and, on examining the body, arsenic could be de- 
tected in the urine, and in the liver ; the digestive tube was 
inflamed. 
Arsenic acid reacts with colcothar and hydrated peroxide, 
precisely as the arsenious acid. 
I conclude from the preceding facts : 
1. That colcothar should never be employed as an antidote 
to arsenious or arsenic acid, because it does not neutralize 
thesetjpoisons, even in an exorbitant dose. 
2. That dry hydrated peroxide of iron absorbs and neutra- 
lizes a large amount of these acids, forming sub-salts of iron, 
which are poisonous, but less deleterious than the acids them- 
selves ; the unfortunate results from these sub-salts evidently 
depends upon their decomposition by acids contained in the 
stomach, and the consequent absorption of the liberated ar- 
senical acid. 
3. It is consequently useful to administer this dry hydrated 
peroxide, previously ^suspended in water, especially if vomiting 
be produced ; for then, independently of that part of the poi- 
son expelled in the state of the arsenical acid by vomiting, 
the patient will also reject the sub-salt of iron, which is 
formed in the stomach and which will contain a considerable 
portion of the arsenical acid. 
4. That when vomiting is not produced we should but 
slightly fear the presence in the stomach of the sub-arsenical 
