NEW RESEARCHES ON OPIUM. 
63 
public some processes applicable to this branch of chemical 
analysis, have all determined me to write on a subject, consi- 
dered by many as exhausted, but in which I on the contrary 
think that much remains to be done. 
II. 
When opium is treated by the experimental chemist, it 
rarely happens that he is enabled to operate on large masses, 
hence it happens that some of its immediate principles, espe- 
cially those which exist in minute proportions, almost always 
escape notice. In a manufactory, where processes are per- 
formed on a large scale, other causes of disappointment present 
themselves, and great precision is hopeless. As large quanti- 
ties of the raw material are acted upon, the processes become 
very tedious, and much time is required for the various mani- 
pulations; as filtering, evaporation, &c; hence substances are 
liable to change, to react on each other, or to be totally de- 
stroyed; in short, the modes of extraction applicable to certain 
immediate principles of vegetable origin, on a small scale, are 
not practicable when large masses are to be operated upon. 
But the result of those operations which too generally are 
promulgated, are of interest to science, and often merit the 
widest circulation. My researches of late have principally 
been directed to the examination of a large quantity of mother 
waters, left after the separation of morphia. 
III. 
Examination of the ammoniacal mother waters of 
Morphia. 
To obtain narceine and meconine, I have already said, that 
after having separated the morphine, narcotine and meconic 
acid from a watery solution of opium, by means of ammonia 
and barytes, the fluid must be evaporated to a certain point, 
and then suffered to stand till the crystals form; there is here 
great difficulty in acting on large quantities. If evaporation 
be not carried far enough, the fluid ferments and becomes co- 
vered with mouldiness; affording only denaturalized products 
