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SELECTED ARTICLES. 
which evaporates during the preparation of the pills. These 
pills do not differ from the compound depurative powder of 
Plummer. Journ. de Pharmacie, 
ART. XXL— NOTE UPON THE PREPARATION OF SIMPLE 
PLASTER. * By M. A. Gelis. 
All chemists agree in stating that the simple plaster of 
pharmaceutists is a compound analogous to salts. M. Chev- 
reul in his treatise upon fatty bodies, says: " The operation of 
saponification, thus generalized, shows that the preparation of 
plaster with litharge is a true saponification, the oxide of lead 
having the same action upon fat as potassa and soda. Hence 
it follows that, strictly, plasters can be prepared with saponified 
fat obtained from an alkaline soap — but before so doing, it is 
necessary to determine if, in the plaster which it is desired to 
imitate, there exists a proportion of fat not acidified, so that if 
this is really the case, this proportion of non-acidified fat may 
be added to that which is saponified before uniting with it the 
litharge.^' 
I might easily multiply these quotations, for all who have 
written upon this subject have taken the same view of the 
♦ The simple plaster of the Codex, corresponds to the Emplastrum 
Plumbi of the U. S. Pharmacopoeia. In the latter work olive oil alone is 
directed in the proportion of 1 gallon to 5 pounds of litharge and 2 pints 
of water; in the former we have the following formula. 
Take of finely powdered litharge, 
olive oil, 
laid, 'jn lbs. iij. 
M. water, quantum suf. 
For an exposition of the views entertained at present by chemists upon 
the changes which these substances undergo in the process by which they 
are enabled to react upon each other, we refer to the U. S. Dispensatory. 
Ed. 
