64 ON INDIGENOUS OPIUM. 
of several samples contains most pure morphia; the most 
simple assay gives even more sensible differences, because 
the least rich opium is that which leaves in the solution a 
larger proportion of morphia relative to the quantity which 
it contains. 
It would be desirable for all pharmaciens to take the 
trouble of testing the medicinal opium which they buy ; 
they could then present to practitioners medicines less va- 
riable in their effects, and they would assist in the destruc- 
tion of frauds, which would cease to be profitable to their 
authors, and which are sometimes so prejudicial to the in- 
terests of medicine. — Chemist, from Jo urn de Chem Med. 
ART. XIX. PREPARATION OF MERCURIAL OINTMENT. 
By M. Fossembas. 
Few Pharmaceutical preparations have given rise to so 
many investigations and theories as mercurial ointment ; 
so much has been said on this subject, that the following 
may at first sight appear fastidious and useless. 
I admit that it is not without a certain feeling of diffidence 
that I publish these observations, which have led me to 
the employment of a process by which I am able to prepare, 
in less than an hour, eight pounds of mercurial ointment. 
The process which I have followed has nothing new in 
it, since it consists merely in the use of rancid grease ; but 
it is of such easy and rapid execution, that I have considered 
it my duty to rescue it from the oblivion into which it has 
fallen. 
