PRACTICAL OBSERVATIONS. 
123 
Take of Subcarbonate of Iron, 6 ounces 
Muriatic acid, 1 pint, 
Alcohol, 2 do., 
Strained honey, 1 do. 
Pour the acid upon the subcarbonate of iron, and shake the 
mixture occasionally for three days ; then set by, that the dregs 
may subside ; lastly pour off the liquor and add to this the alco- 
hol and honey previously mixed. * 
Ointment of Med Oxide of Mercury soon loses its fine red 
color, as ordinarily prepared. To remedy this it has been sug- 
gested to prepare the simple ointment or lard by digesting it on 
poplar buds ; or to dissolve a portion of benzoic acid in it, both 
of which methods are effectual, but attended with some trouble. 
A more simple and equally effectual method is, to add two drops 
of liquor potassge to each ounce of the freshly prepared oint- 
ment, f 
Tincture of Kino. Having experienced the difficulty of pre- 
serving this tincture from undergoing change in constitution, 
* We dissent from the author in regard to the presumed advantages pre- 
sented by the above formula. It was the design of the originators of the 
preparation to get a sesquichloride of iron in alcoholic solution. The Dub- 
lin Pharm: (1826) directs rust of iron. The Edinburgh Pharmacopoeia, 1841, 
directs red oxide of iron. The Codex directs sesquichloride of iron to be 
dissolved in alcohol. The new Dublin Pharmacopoeia, the latest British 
Pharmacopoeia published, directs a solution of sesquichloride of iron to 
be made by dissolving iron wire in muriatic acid, and converting the proto- 
chloride of iron into sesquichloride, by adding nitric acid. The only rea- 
son for using subcarbonate of iron, is, that it is the most convenient and 
most soluble form of sesquioxide, obtainable. The reason the tincture pre- 
cipitates, is because a small quantity of protochloride of iron is formed 
from the four or five per cent of carbonate of the protoxide that the sub- 
carbonate contains, and this is slowly converted into sesquichloride and 
sesquioxide, which precipitates. The Pharmacopoeia U. S. for 1850, gives a 
process for making this preparation in as many hours as that of 1840 
requires days. Hence the design of the author in employing honey is of 
little use, and accomplishes nothing beyond preventing the decomposition 
of a little protochloride of iron, which had better be absent than present. — 
Editor. 
-j-The same preservative effect is derived from liquor potassse, when 
added to iodide of potassium ointment — the elimination of free iodine 
and consequent coloration of the ointment ; being prevented by the alkali. — 
Editor. 
