.98 
ORIGINAL COMMUINCATIONS. 
The Muriated Tincture of Iron. Whenever iron is ad- 
ministered in the liquid form, the tincture of the muriate is 
the preparation usually resorted to. It possesses, in addition 
to its properties as an active chalybeate, that of being ac- 
ceptable to the stomach, and easy of administration. There 
can be no just reason for its variance in strength, as is fre- 
quently the case; much circumspection is certainly required 
in its preparation; but when due care is taken, it will gene- 
rally be obtained of nearly the same strength. 
There are several causes that may influence its preparation; 
any difference in the strength of the acid, allowing the base to 
be always the same, must necessarily vary the product; any 
mixture of the peroxide of iron, obtained from the protosul- 
phate by heat, with the base, may vary the strength. Equal 
quantities of two tinctures, one made from the precipitated 
carbonate and one from the peroxide, obtained from the proto- 
sulphate, yielded for the first 40 grains of peroxide of iron, 
and for the latter, 17 grains. Exposure to the air is likely 
also to weaken the tincture. The protoxide of the protomu- 
riate being changed by the absorption of oxygen to the per- 
oxide, which, requiring a larger proportion of acid for satura- 
tion, is partly precipitated; there is more or less of this pre- 
cipitate according to the quantity of protomuriate in the tinc- 
ture. 
A tincture made from a peroxide resulting from the pre- 
cipitated carbonate, deprived of its carbonic acid by heat, did 
not precipitate during several weeks exposure. 
The only certain test of its strength is to ascertain the quan- 
tity of peroxide it contains. This may be done by adding a 
solution of caustic potash to a given quantity of the tincture, 
until it ceases to precipitate. The peroxide is thrown down 
in the form of a bulky hydrate; this is to be thoroughly 
washed and dried. 1000 grains of the tincture, made accord- 
ing to the national pharmacopoeia, yielded 79 grains of the 
peroxide of iron. This very nearly agrees with Mr. Phil- 
lips' test of a tincture prepared by himself. 
Mr. Phillips states that muriatic acid of the officinal specific 
