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PHVRMACUTICAL NOTICES. 
ART. XXXII.— PHARMACEUTICAL NOTICES. NO. xvin. 
By Augustine Duhamel. 
Bi-Carbonate of Soda, 
As the article of Bi-Carbonate of Soda is very extensively 
used in this country, and is prepared on a large and economi- 
cal scale by our manufacturers, it is of the highest importance 
that our apothecaries should be made acquainted with the 
method by which it is made. In a communication published 
in this Journal (vol. 1st, second series) by F. R. Smith, some 
attention was directed to this subject, by a mention of the 
fact, that while the different Colleges directed a formula for 
Bi-Carbonate of Soda, (but resulting in a sesqui-carbonate, as 
was proved by Phillips, the English chemist,) our manufac- 
turers were engaged in making the article by a novel process 
which furnished a bi-carbonate with which our shops were 
then, and are still, supplied. Mr. S. mentioned that it was 
made by directing a current of carbonic acid gas through dry 
carbonate of soda, but gave no particulars in relation to the 
construction of the apparatus. The U. S. Pharmacopoeia, un- 
der the head of Bi-Carbonate of Soda, directs it to be prepared 
by transmitting carbonic acid gas through carbonate of soda 
in solution. The London Pharmacopoeia, last edition, gives the 
same process under the title of Sesqui-Carbonate of Soda. We 
have, therefore, a formula, authorising, as officinal, a substance 
not generally, if at all, found in the shops. 
The following details, prepared from the formula given in 
the French Codex, which is that of the manufacturers, and 
pursued in all the large laboratories of this country, from 
whence our supplies are derived, convey, assisted by the 
drawing, all the information necessary to an apothecary 
to enable him to prepare his own Bi-Carbonate of Soda. 
Take of Carbonate of Soda in crystals, any quantit}'. 
Provide a deep wooden box, slightly conical with the narrow part 
downwards, and furnished at its inferior part with a diaphragm 
pierced with holes, placed at a little distance from the bottom. 
