PRUSSIC ACID, ANTIMONY, AND ARSENIC. 
145 
is precipitated in a manner so complete by the hydrated peroxide of iron recently pre¬ 
cipitated and suspended in water, that a current of sulphuretted hydrogen directed 
through the liquid, filtered and acidulated with a small quantity of hydrochloric acid, 
no longer presented the least trace of arsenious acid. I have also found that if to this 
body some drops of ammonia be added, and if it then be digested at a gentle heat with 
arsenious acid reduced to an impalpable powder, it transforms this last substance very 
quickly into a basic arsenite of peroxide of iron, which is altogether insoluble. A series 
of experiments, founded on this observation has produced in me the firm conviction that 
this body combines the most favourable conditions as an antidote against the poisonous 
action of arsenious acid, both in a solid state and in solution. Dr. Berthelot has very 
willingly, at my request, acted in concert with me in the examination of this subject 
under all its aspects, and in making it the object of more careful experiments. 
“ Ihe results of this examination have gone much beyond our expectations, and have 
confirmed our persuasion that the hydrate of peroxide of iron is a better antidote for 
arsenious acid, both solid and dissolved, than albumen is for corrosive sublimate. 
r ‘‘ Young dogs, less than a foot in height, to which we had given from 4 to 8 grains 
oi arsenious acid reduced into fine powder (and after exhibition of the hydrate, a liga¬ 
ture having been applied to the oesophagus to prevent vomiting), lived more than a 
week, without presenting, either during life or on dissection, the slightest trace of arse¬ 
nical poisoning. 
“ The excrements—which were, as might have been expected from the complete de¬ 
privation of both meat and drink, in very small quantity—contained almost the whole 
of the arsenious acid, in the form of basic arsenite of peroxide of iron, but contained not 
a trace of free arsenious acid. We have convinced ourselves, by experiments on animals, 
that a quantity of hydrate of Fe 2 0 3 , answering to from 2 to 4 drachms of Fe o 0 3 , mixed 
with 16 drops of ammonia, is sufficient to transform in the stomach 8 to 10 grs. of well 
powdered arsenious acid into insoluble basic arsenite. 
)• It is, besides, easy to see that we might, in cases of poisoning by arsenic, administer 
this body in proportions much more considerable, with or without ammonia, either by 
the mouth or by injection, since the hydrate of Fe 2 0 3 , being a body altogether insoluble 
in water, exercises absolutely no action on the animal economy.” 
The ammonia above recommended by Bunsen can be of no use unless there 
should be acid in the stomach, and if this should be considerable, the small 
quantity of ammonia that could be given would go but a short way in neu¬ 
tralizing the free acid. It would, in our opinion, be better for the medical 
man to counteract the interfering action of the free acid by the liberal use of 
calcined magnesia, or a sufficient excess of the hydrated peroxide of iron. 
Should vomiting have occurred, the action of the vomited matter on test 
paper would be a useful guide to the medical man. 
Although the absorbing power of the hydrated oxide upon arsenious acid 
is much lower than was found by us, it would be safest to fix the quantity to 
be used, in any case of poisoning by arsenic, on Bunsen’s suggestion.* Sou- 
beiran and Miquel found that dogs to which 12 grs. of white oxide of arsenic 
had been given died in about two hours, but other dogs that had got 18 grs. of 
arsenious acid along with twelve times that quantity of peroxide of iron in the 
state of hydrate, recovered completely. Vomiting was prevented in all cases 
by the application of a ligature to the oesophagus. 
< Soubeiran and Miquel have found that at the least twelve times the quan¬ 
tity of peroxide of iron in the form of hydrate is required to destroy the 
poisonous effects of one part of arsenious acid supposed to have been taken. 
Dr. Brett’s paper, in the fifteenth volume of the ‘ Medical Gazette,’ contain¬ 
ing a denial of the antidotal power of hydrated peroxide of iron on arsenic, is 
.* One of the writers of this paper has reason to entertain grateful feelings in connection 
with Bunsen’s antidote, as he probably owes his life to the prompt use of it, along with other 
means, after having, by an awkward mistake, swallowed a poisonous dose of Donovan’s 
solution. 
