
(CGEM) 
XXII.— Researches on some of the Crystalline Constituents of Opium. 
By Tuomas ANDERSON, M.D., F.R.S.E. 
(Read 5th April 1852.) 
Since the year 1803, when DEsronz discovered the substance which afterwards 
received the name of Narcotine, the chemical investigation of opium has engaged 
the attention of many skilful and distinguished chemists, and in their hands has 
proved the source of a series of substances, unprecedented in their number and 
the variety of their properties. Up to the present time, there have been de- 
tected in it no less than eleven different substances,* one acid, and ten, either 
basic or indifferent, all presenting definite characters and crystalline form, besides 
various imperfectly characterised substances, described under the names of 
caoutchouc of opium, resin of opium, extractive, and the like. 
With these facts before us, the chemistry of opium may appear at first sight 
to be almost exhausted, and that little remains to be done, except to fill up the 
minor details of former investigations. But when we come to inquire more 
minutely into its history, the meagre and even conflicting statements of different 
investigators, sufficiently indicate the imperfections of their researches, and the 
necessity of revising and greatly extending their inquiries before our knowledge 
can be considered as either definite or satisfactory. The most remarkable con- 
stituents of opium were detected a number of years since, at the time when at- 
tention was first directed to the existence of peculiar constituents on which the 
active properties of vegetables depended ; and since their discovery. compara- 
tively little has been done to confirm the original observations, which are often 
unsatisfactory, and serve not so much to supply definite facts, as to indicate the 
direction in which they are to be sought for. 
Some conception of the limited extent of our information regarding opium 
may be formed by a few preparatory statements as to our present knowledge of 
its basic and indifferent constituents, amounting, as has been already mentioned, 
to ten in number. Of these, four have been repeatedly examined within the last 
few years, and their constituents may now be considered as conclusively esta- 
blished. These are:—. 
* Since this paper was written, two new substances have been added to the number of the 
constituents of opium ; these are methylonarcotine and propylonarcotine, which have been recently 
described by WerTHEIM. 
VOL. XX. PART III. 0B 
