io6 THE ALUMNI JOURNAL. \ 



\ 



curate valuation has attracted much out an undue and uncertain loss of alka- 



attcntion, involving extensive experi- loid. Various plans have been proposed 



mental work. The alkaloids of opium and tried to overcome this difficulty, 



vary in proportion, but the following Firstly, and most obviously, the treating 



percentages given by Pictet ("Alkaloides of the crude morphia precipitate with \ 



vegetaux," p. 173) may be regarded as benzene and the like to remove impuri- 1 



not far wide of the mark. ties. By this means narcotine and its 



Morphine- _-__ 10 allies, codeine and resinoid are removed, 



Narcotine 6 u i. i.i. -j • r r i. • 



. but the residue is far from being pure 



Papaverine i b tr , 



Codeine 05 morphine. Moreover, it is found that the 



Thebaine 0.3 precipitate obtained by rendering alka- 



Narceine _ 0.2 line a mere aqueous extract of opium 



The morphine is usually in larger pro- does not contain the whole of the mor- 

 portion. The alkaloids exist in com- phine, or otherwise, that the separation 

 bination with sulphuric and meconic is so gradual and irregular as not to be 

 acids. Although codeine is the only one complete in a reasonable length of time, 

 of the minor alkaloids which is presently Then came the device of adding a rela- 

 in constant demand, further uses may yet tively large amount of alcohol or mix- 

 be found for some of the others or their ture of alcohol and ether to the aqueous 

 derivatives. For instance, while nar- solution before precipitating with am- 

 cotine is of feeble activity, hydrocotar- monia. By this means the morphine 

 nine, which can easily be prepared separates much more readily, in a more 

 from it, has a decided physiological ac- crystalline and purer form, than from 

 tion. But whatever may be the case in the watery solution. Petit's process and 

 the future, opium is at present invariably Fliickiger's earlier process partake of 

 assayed by determining the amount of this nature. In practice, such methods 

 morphine which it contains. The pro- are quite unsatisfactory. The loss of 

 cesses employed for the purpose have morphine is considerable, and varies so 

 undergone a gradual evolution, so that greatly with the quality of opium, tem- 

 the methods now in vogue compare very perature and circumstances that a true 

 favorably with those of the earlier years correction of loss is impossible. The in- 

 of the century. Some of these earlier troduction of lime in assaying opium is 

 determinations are quite misleading as generally attributed to Mohr, and ap- 

 the crude precipitate weighed as mor- peared to be a decided improvement. A 

 phine does not afiford any accurate indi- modification of this process was official 

 cation of the amount of that alkaloid in the 1867 British Pharmacopoeia. The 

 actually present, Even now there is by first improvement on the process was to 

 no means unanimity of opinion or uni- abolish the boiling with the lime, which 

 formity of practice in regard to this mat- was an unwise and decomposing per- 

 ter, although we are rapidly coming to a formance; and now as improved by var- 

 clear understanding of the subject. Gen- ious chemists, it is a method widely used 

 erally speaking, the difficulty attending and is official in the present British Phar- 

 an accurate assay of opium may be stat- macopoeia. Briefly stated, it consists in tri- 

 ed: that on account of the chemical con- turating a weighed portion of opium with 

 ditions in which the morphine exists in excess of lime and water, filtering, tak- 

 the drug it is impracticable to precipi- ing what is supposed to represent hall 

 tate the morphine in the pure state with- the opium, adding to it alcohol, ether. 



