ON THE PROTOMURIATE OF IRON. 
275 
of liquid, after saturation, is just double. Whatever may 
be its bulk, however, it contains about 150 grains of prot- 
oxide of iron, so that the other fluid must be added till 
the solution contains thirty-two grains of the protoxide to the 
ounce. 
The principal advantage of this process is, that a given 
amount of acid requires a much larger portion of iron for its 
saturation than when the peroxide is used, because the per- 
muriateisa sesquimuriate. Thus, (3Fe.O) + (3Cl.H)— (Fe 2 3 ) 
+ (3Cl.H) = Fe. 1 equivalent; consequently, in saturating three 
equivalents of muriatic acid with the protoxide and peroxide 
respectively; there is one whole atom, or fifty per cent, of 
iron, more in the former than in the latter; hence the muriate 
of the protoxide is decidedly to be preferred. 
The following is a formula for tincture of muriate of iron: 
P- — Acid. Hydrochlor. gij. (troy.) 
Ferri Protocarb. q. s. ad saturand. 
Mellis, gijss. 
Alcoholis, q. s. 
Saturate the acid with the carbonate, then add the honey, and, 
finally, sufficient alcohol to make nineteen fluid ounces of 
tincture. — After standing six hours, filter for use. 
Carbonate of iron can be advantageously employed in 
making the tartrate and acetate of iron, and the tartrate of iron 
and potassa. 
