THE 
AMERICAN JOURNAL OF PHARMACY. 
OCTOBER, 1 844. 
ART. XXXVIII. — ON PRECIPITATED CARBONATE OF LIME. 
BY ROBERT BRIDGES, M. D. 
The precipitated carbonate of lime, which is an officinal 
preparation of the Dublin Pharmacopoeia, has of late found 
much favor with some physicians, as capable of producing 
a mixture superior to the prepared chalk, in being more 
free from grit. The preparation most esteemed is the im- 
ported article, an opinion having been expressed, that the 
preparation as generally manufactured here, is not superior 
in its state of division to the ordinary prepared chalk. As 
the article is modified very essentially as to its pulverulent 
state by the mode of its production, the following observa- 
tions may not be irrelevant at the present time. 
The circumstances modifying the minuteness of the di- 
visions may be comprised under three heads — viz : 
1. Density of the solutions used. 2. Nature of the com- 
pounds used to produce the double decomposition. 3. The 
temperature at which the precipitate takes place. 
It may be premised that under all circumstances of pre- 
cipitation, carbonate of lime has a strong tendency to as- 
sume a crystalline form and structure, as is very manifest 
in stalactital concretions, which are generally formed by 
the precipitation of carbonate of lime from its solution in 
water by means of carbonic acid. The same structure is 
also produced, on mixing a solution of lime with any so- 
luble carbonate — although in some instances it may require 
a high magnifying power to detect the crystalline form. 
vol. x. — NO. III. 15 
