278 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [September 30, 187L 
|toUs aifo Ernies. 
*** In order to facilitate reference, correspondents are 
requested to mark their answers in each case with the title 
and number of the query referred to. 
No notice can be taken of anonymous communications. 
All queries or answers should be accompanied by the name 
and address of the writer. 
[280.]—DISPENSING.—For potass, hydr., I should 
think, without a doubt, potassii iodidi is intended, the 
dose being only l 1 25 grains in excess of the maximum 
dose of the P. B., the caustic potash being never given 
internally, except in the form of liquor potassii.—S. 
Newbury, Medical Hall, Dorking. 
OINTMENT CONTAINING MUCH WATER.— 
The following recipe was recently handed to me to be 
filled :— 
P> Pyroligneous Acid, 
Sulphur, each 4 oz. 
Calomel, 60 grs. 
Red Precipitate, 40 grs. 
Spt. Turpentine, 1J oz. 
Lard, 4 oz. M. 
I first intimately mixed the calomel and precipitate, 
then by degrees the sulphur, the turpentine, and finally 
a small portion of the lard. I now added a little, say 
two fluid-drachms of the acid, but entirely failed to get 
a mixture. As the acid is largely composed of water, 
the object was to dispose of the latter so that it might 
not interfere with the mixture. This was done by add¬ 
ing to the salve in the mortar a little wheat flour, with 
perfect success, after which lard, flour and acid were 
added alternately until the ointment was finished, leaving 
out of it as much lard as flour had been substituted. 
Four hours afterward, the ointment not having been 
called for yet, and the weather being very warm, it was 
found that some of the lard had melted, and was floating 
on the top, but readily mixed with the ointment again 
on making use of a spatula, but no part of the acid at 
any time separated from it.— John H. Ehlers in the 
American Journal of Dharmacy. 
THE CHEMISTRY OF TAKING OUT IRON- 
MOULDS.—Although the routine method of doing this 
is familiar to every chemist, the chemical reactions in¬ 
volved are by no means generally understood, and there¬ 
fore a brief account of them may not be unacceptable. 
My attention was first called to the subject while 
testing the comparative efficiency of three familiar sol¬ 
vents of ferric oxide, viz. hydrochloric acid, oxalic acid 
and quadroxalate of potassium—the sal acetos. 
I was surprised to find that the latter, which I had 
regarded as most eligible merely for its convenience ha 
application, was superior also in solvent power. When 
hydrated peroxide of iron is treated with a strong hot 
solution of sal acetos, in the proportion of two equiva¬ 
lents of the latter to one of the former, carbon dioxide is 
copiously evolved, the oxide is dissolved, and at the 
same time chiefly, if not wholly, reduced to the ferrous 
state. 
The resulting solution is yellowish-green in colour, 
yields a well-marked precipitate with potassium ferrid- 
cyanido, and appears to contain ferrous oxalate and 
neutral potassium oxalate. The following is the equa¬ 
tion :— 
Fe 2 0 3 H 2 0 + 2KHG 2 0 4 H 2 Co0 4 2H,0 
= 2Fe C 2 0 4 + K 2 C 2 0 4 + 2C0 2 + 8H 2 0. 
The same result followed when the oxide was acted 
upon by a strong solution of oxalic acid at a boiling heat, 
but less quickly, moreover the resulting solution was of 
a deep yellowish-brown colour, and contained more ferric 
salt. 
Three equivalents of oxalic acid to one of oxide wer© 
employed, as in the following equation : — 
Fe„0 3 H 2 0 + 3H 2 C 2 0 4 2H,0 
= 2 Fe C 2 0 4 + 2C0 2 '+ 10H 2 O. 
Knowing that a mixture of sal acetos and cream of 
tartar is sometimes sold as salt of lemons, I next tested, 
the solvent power of this combination. 
Taking as my guide the proportions employed in. 
making the ferrurn tartaratum of the Pharmacopceia,. 
I compared the action on ferric oxide, of boiling solutions, 
of acid tartrate of potassium, sal acetos and of a mixture* 
of the two. 
Only a small portion of the oxide was taken up by tha- 
acid tartrate either alone or combined, and the equiva¬ 
lent quantity of ferric oxide was dissolved more rapidly 
by the sal acetos alone. 
Experiments performed upon black oxide of manga¬ 
nese showed that it, like ferric hydrate, was dissolved by 
hot solutions of oxalic acid and sal acetos, but reprecipi¬ 
tated as flesh-coloured or buff manganous oxalate, carbon 
dioxide being given off; the following equations show 
the reactions:— 
Mn0 2 + 2 K H C 2 0 4 , H 2 C 2 0 4 2 H., 0 
= MnC 2 0 4 + 2KHC 2 0 4 + 2C0 2 + 6H,0. 
Mn 0 2 + 2H 2 C 2 0 4 2H 2 0 = MnC 2 0 4 + 2C0 2 + 6H 2 0. 
Similar experiments with mercuric oxide failed to give 
any satisfactory result. 
The practical inference is that the compound known 
as sal acetos is by far the best agent for removing either 
iron-moulds or the disfiguring brown stains produced by 
Condy’s fluids. — J. F. Brown. 
[285.]—SYRUPUS CROCI. — “ A. Dr wishes to 
know if any reader has tried the American receipt for 
Syr. Croci, given page 707 (J. AY. Kennedy), and if so, 
what has been the result ? 
[286.]—DISPENSING.—I shoidd like to hear the 
opinion of some of your readers about the dispensing of 
the enclosed prescription, and what appearance it should 
present.—G eorge Ellis. 
Spt. Ammon. Co. 5ss 
Liq. Ammon. Acet. 5ij 
Quince Sulph. gr. x 
Liq. Morph. 5j 
Spt. Ether. Nit. 5iss 
Acid. Citric. 5j 
Potass. Bicarb, ^iss 
Mist. Camph. *iij 
Inf. Gentian, ad ^vj. 
M. ft. mist. 
§j tertia vel 4tis horis. 
[287.]—HOTCHKISS’ OIL OF PEPPERMINT.— 
Some years ago I used to buy H. G. Hotchkiss’ ol. m. pip. 
in original bottles, which would perfectly dissolve in 
s. v. r. 56 o. p. I cannot now procure the same article- 
That I have lately purchased produces a very milky 
liquid. This I presume is the result of adulteration with 
a fixed oil. Can any one tell me how I can procure the- 
genuine article ? I shall be glad to learn the experience* 
of some of my brethren in this respect, and how the* 
turbid liquid can be clarified, for ordinary filtration 
through paper is useless.— Philos. 
[288.]—VEGETABLE PARCHMENT.— ££ Ferrurn ~ 
would be much obliged for full particulars for the manu¬ 
facture of vegetable parchment. 
[289.]—SILVERING SOLUTION.—“ Ferrurn ” also- 
asks for a recipe for a good silvering solution that will 
not tarnish. 
