ON HYDRATED PEROXIDE OF IRON. 
9 
pie: effecting the oxidation of the iron to its maximum ex- 
tent, by the decomposition of nitric acid, and precipitating the 
oxide thus obtained by ammonia. 
It is unnecessary to review these formulae in detail, further 
than to indicate a few reasons for the preference given to the for- 
mula here proposed. If nitric,or nitro-muriatic acid be employ- 
ed as the solvent of the iron, as prepared by one author, violent 
and inconvenient action, and great heat, attend the operation, 
and the clothing and utensils of the operator encounter some 
risk. To this objection our formula is not exposed. And the di- 
rection given by the same authority for " drying the powder 
in the shade" is entirely inconsistent with our whole object, 
the preservation of the oxide in a pulpy state. Another 
writer, anonymous, it is true, but one who evidently under- 
stands his subject, offers two formulae for this preparation. 
The former of which, with the exception of not affixing quan- 
tities, coincides exactly with our mode of preparation, although 
nothing is said by him of preservation, and one expression of 
which is quoted in his own words, because reference will 
shortly be made to it: "The alkali throws down the hydrated 
peroxide as a reddish precipitate, which must be carefully 
washed." In his second process he "speaks of its extempora- 
neous preparation, "by boiling aqua fortis in a common iron 
pot, with some iron filings or nails, for a few minutes, pouring 
off the clear liquor, and then adding to the fluid a saturated 
solution of carbonate of soda, the hydrated peroxide will be 
precipitated in the form of a reddish powder. A saturated 
solution of the nitrate of iron, as also of the carbonate of soda, 
may be kept in separate bottles in the office of a physician, 
and the antidote made whenever required, by merely mixing 
a portion of each solution with the other." To this formula 
and recommendation there are two objections, of which one 
may be regarded as serious, viz.: that by this extemporaneous 
preparation the oxide is not washed, and the highly irritated, 
if not inflamed, mucous coats of the stomach and oesophagus 
are deluged with a concentrated solution of nitrate of soda, 
"whose irritant properties," says Professor Ducatel, in his 
VOL. VI. — NO. I, 2 
