PHARMACEUTICAL NOTICES*, 
183 
ART. XXXVI.— PHARMACEUTICAL NOTICES. No. XX. 
By William Procter, Jr, 
Valleys Protocarbonate of Lime. 
Many have complained of the difficulty attending the sue" 
cessful accomplishment of the process for making this prepa- 
ration. The extent to which it is now used in this medical 
community, and perhaps in others, makes a thorough know- 
ledge of the details of manipulation in the process for its 
manufacture, very desirable. The greatest difficulty which 
has heretofore attended the process, is the evaporation of the 
water, from the mixture of hydrated oroto-carbonate of iron 
and honey. Too high a temperature causes the decomposi- 
tion of the carbonate, which is only prevented under ordinary 
circumstances by the presence of the saccharine matter. If, 
on the contrary, too little heat is used, the evaporation is so 
slow, as to make the process inconveniently long ; not to 
speak of the protracted exposure of the salt to the action of 
the atmosphere. 
By suspending a thermometer in the mixture during the 
process, it was found that the evaporation would proceed suc- 
cessfully at the temperature of 150° Fahr. ; but much beyond 
that point, the evolution of carbonic acid gas commenced, and 
was rapid at the temperature of boiling water ; and hence, 
that by keeping the mixture steadily at 150 degrees, the end 
desired was attained in the shortest time, .compatible with the 
excellence of the product. 
As some time has elapsed since the publication* of the pa- 
pers on this subject, it is thought that are-statement of the for- 
mula will not be out of place at this time. 
Take of Proto-sulphate of Iron, (crystallized,) gxvj. 
Carbonate of Soda, (crystallized,) ^xix. 
Clarified Honey, 
Boiling water, of each a sufficient quantity. 
* See Vol. x, pages 214 and 272, of this Journal 
