THE OPIUM FOUND IN COMMERCE. 
323 
I will merely remark, that you must be careful to employ 
a very limpid solution, marking about 20°, by the hydrometer 
for salts. If more concentrated, the narcotine deposits with 
too much difficulty; if weaker, its action becomes feeble, and 
the operation is less prompt. So when you wish to assure 
yourself of the purity of some morphine, it will be sufficient 
simply to weigh a determined quantity, reduce this to pow- 
der in a porcelain mortar, then add to it the solution of potash 
in excess, and shake it. If the whole of the powder dissolves, 
and after having poured the liquid into a test glass, it remains 
limpid, then you have operated upon pure morphine; but if, 
on the contrary, the liquid remains cloudy, and after half an 
hour's repose, forms a crystalline deposit, this deposit will 
be narcotine. Nevertheless, to be assured of the success of 
the operation, it will be well to decant the potash liquid and 
triturate the insoluble portion once again, with some solution 
of potash; afterwards, wash well the residuum with water, to 
take up the potash with which it is impregnated, and collect 
it upon a filter, when you can ascertain the proportion it bears 
to the morphine. As to the morphine dissolved by the pot- 
ash, it will be observed, that, after twenty-four hours, it will 
begin to crystallize, according as the solution becomes satu- 
rated with the carbonic acid of the air : but if you wish to 
withdraw it immediately, all that is necessary is to saturate 
the solution, allowing a slight excess of acid, then adding 
ammonia to the liquids brought to the boiling point, and you 
will obtain it precipitated in a grained form. 
I have always followed this process in analysing the adul- 
terated morphine which I had at my disposition. However, 
as I wished as much as possible to collect the narcotine, such 
as it had been introduced into the mixture, I contented my- 
self with merely shaking the suspected morphine without 
trituration, with several different portions of solution of potash, 
and decanting each time the alkaline liquid. I afterwards 
washed the residuum in water, sharpened with acetic acid, in 
the view of removing from it either some little morphine that 
might remain, or a little potash; and having satisfied myself, 
