146 
ON AN ANTIDOTE AT ONCE FOR FRUSS1C ACID, ETC. 
of no value; the experiments are altogether fallacious,—the conditions laid 
down by Bunsen having been so completely departed from, that he could 
have been told beforehand, by that savant, that the results of the experi¬ 
ments were nothing else than what were to have been anticipated. 
For instance, 10 grs. of hydrated peroxide of iron were used along with 
2 grs. of arsenious acid; whereas ten times the amount of the arsenious acid 
supposed to have been taken is the quantity of peroxide of iron, in the form 
of hydrate, declared by Bunsen to be necessary to remove the poison ; and if 
by the 10 grs. are meant (for his meaning is not very clear) 10 grs. of per¬ 
oxide of iron in the form of hydrate, in place of 10 grs., there should have 
been 20 grs., double the quantity used by Dr. Brett. If he used only 10 grs. 
of the hydrate (and weighed in that state), the quantity was actually between 
forty and fifty times too small. 
His other experiments are equally fallacious, in either using ordinary oxide 
of iron, or the chemical compound of arsenite of iron, produced by double de¬ 
composition between an alkaline arsenite and a persalt of iron, neither of 
which had Bunsen ever stated to have any antidotal action. If the antidotal 
action of hydrated peroxide of iron depends on the formation of an insoluble 
arsenite, it must be an exceedingly basic compound, containing somewhere 
about 10 equivalents of Fe 2 0 3 to 1 equivalent of As 2 0 3 . A compound, of 
such a nature must have been obtained in the filter by Dr. Brett on washing 
the arsenite of iron, and continuing the washing till no more arsenic could be 
detected in the washing water. The oxide of iron after this operation still 
contained arsenic. 
While engaged in these experiments on the antidotal action of hydrated 
oxide of iron on the poisonous effects of arsenic, the remarkable case of 
Dr. Pritchard had just occurred; aud it at once occurred to us, that there 
was a great likelihood, principally from the many chemical relations of anti¬ 
mony to arsenic, that the hydrated oxide of iron might also be an antidote to 
the poisonous action of antimony. 
A few experiments soon confirmed, in the fullest manner, our anticipations. 
A mixture of solution of perchloride of iron, containing 80 grs. of anhydrous 
peroxide of iron and a solution of 1 oz. avoirdupois of crystallized car¬ 
bonate of soda, was prepared; to this mixture, containing hydrated peroxide 
of iron and chloride of sodium, was added a solution of 10 grs. of tartar 
emetic: the whole was thoroughly agitated, and thrown on a filter. The 
filtered liquid, acidulated with muriatic acid, was tested with sulphuretted 
hydrogen for antimony, but not a trace was found. The filter, with its con¬ 
tents, was then mixed with other 10 grs. of tartar emetic, which were again 
removed by the oxide of iron. A third quantity of tartar emetic added was 
almost entirely removed, so that 80 grs. of hydrated peroxide of iron ab¬ 
sorb nearly 30 grs. of tartar emetic from solution. 
The absorbing action of hydrated oxide of iron towards antimony would be 
still more striking but for the dissolving power of the tartaric acid, set free, 
upon the peroxide of iron. That the oxide of iron does not merely act by 
taking the organic acid and precipitating the oxide of antimony in an in¬ 
soluble state, is shown b}^ using hydrate of magnesia instead. In this case, 
even with a much smaller quantity of tartar emetic, the filtered liquid gives 
antimony in abundance to the proper tests. 
To be suitable for the antidotes, the liquor ferri perchloridi must answer to 
the following tests :—one fluid drachm must contain 15'62 grains peroxide of 
iron, ammonia must give a pure reddish-brown precipitate, without any shade 
of black; it must not smell strongly acid, nor, after slight dilution, give a 
brisk effervescence with a piece of zinc. 
Directions proposed to be attached to each bottle of Liq. Ferri Perchloridi.:— 
