124 
Selected Articles, 
coveries may prove to be correct, and to propose new modes 
pf operating; T am of opinion that every investigation that 
tends to make a wise application of the data furnished by 
.analysis to formulas almost always founded on empiricism, 
must necessarily advance the art of pharmacy. With this 
view, I undertook a theoretical examination of the prepara-* 
tions of opium. 
I will show, in the first instance, how greatly the opinions 
of chemists on its chemical composition have varied at dif- 
ferent epochs ; and the influence these changes of sentiment 
has exercised on the mode of administration of this remedy. 
It was long supposed that the action of opium on the ani- 
mal economy depended entirely on the presence of volatile 
principles. Hence the general use of a distilled water of 
opium, of tincture of opium, of an extract of opium prepared 
by maceration with a small quantity of water, and concen- 
trated in a water bath. 
Afterwards, new observations having led to the opinion 
that it was possible to render opium purely sedative in its 
operation, the existence of several active principles was ad- 
mitted ; some of a volatile nature and narcotic, and others of 
a fixed character and sedative. 
Hence arose the torrefaction of opium, its mixture with 
aromatics to disengage, or at least to neutralize its narcotic 
powers; hence also the preparation of extract of opium by 
decoction and prolonged digestion, according to the methods 
of Hombert, Diest and Baume; by fermentation according 
to the plan of Deyeux ; by fermentation in quince juice, as 
recommended by Langelot. All these modes of preparaiion 
were evidently principally intended to separate or alter the 
volatile narcotic principles, and to preserve in the extract 
such only as were fixed and sedative. 
At a still later period, about 1804, when Derosne and 
Seguin had demonstrated the existence of a peculiar crystalline 
substance in opium susceptible of acting on the animal econ- 
omy in a marked manner, without its having been shown by 
experiments that the crystalline substance of Derosne differed 
in an essential manner from that of Seguin; the crystalline 
