274 
ORIGINAL COMMUNICATIONS. 
cess for making several ferruginous preparations, with a cer- 
tainty and accuracy that will go far to recommend its use. 
Tincture of Muriate of Iron. — The formula of the U. S. 
Pharmacopoeia consists in acting on the precipitated carbonate 
of iron with muriatic acid, and afterwards adding a given 
quantity of alcohol. Owing to the variable nature of the pre- 
cipitated carbonate, as respects the proportion of protoxide of 
iron which it contains, we have a preparation varying in 
strength; besides, a portion of uncombined acid remains, 
which reacts on the alcohol, as is evident from its etherial 
odor. 
The process now offered is to take any quantity of officinal 
muriatic acid and saturate it with Vallet's carbonate of the 
protoxide of iron; by these means a solution of the proto- 
muriate of iron is obtained, which contains a quantity of the 
ferruginous salt in proportion to the strength of the acid 
employed. To this solution as much alcohol is to be added 
as will reduce the preparation to the proportion of thirty-two 
grains of the protoxide, or about sixty-four grains of the 
protomuriate, to the ounce of tincture. 
In this state, however, there is a continual liability to the 
absorption of oxygen, by which a portion of the proto- is con- 
verted into permuriate, and to the separation of peroxide of 
iron. To remedy this inconvenience, a portion of honey is 
to be added to the muriatic solution at the time of its mixture 
with the alcohol. This saccharine substance protects the 
protosalt, at the same time that it does not interfere with the 
chemical or therapeutic properties of the medicine. 
In making the muriatic solution, take 480 grains of muriatic 
acid, of sp. grav. 1.16, which contains 32.32 per cent, of acid, 
and saturate it with protocarbonate of iron: consequently, 
for every thirty-seven grains of muriatic acid, thirty-six 
grains of protoxide of iron are required ; so that 32.32 x 4.80= 
154.836 ofacid, then as 37 : 36 :: 154.836 •• 150.651, the quan- 
tity of protoxide of iron required to the ounce of muriatic acid. 
Owing to themoist state of the carbonate, when used,theamount 
