XII.— Researches on some of the Crystalline Constituents of Opium. Second Series. 
By Tuomas AnpERSON, M.D., Regius Professor of Chemistry in the University 
of Glasgow. 
(Read 3d January and 1st May 1854.) 
In pursuing the investigation of the crystalline constituents of opium, which 
formed the subject of a previous communication to this Society, I have succeeded 
in obtaining from the same mother liquor which formed the raw material of my pre- 
vious researches, a considerable quantity of papaverine, the base recently detected 
by Merck, and of meconine, the indifferent crystallizable substance discovered by 
Coverse in the year 1830. The former was encountered quite unexpectedly in 
the precipitate from which narcotine and thebaine were prepared by the process 
described in the first series of these researches. The latter was only obtained 
after many fruitless trials, in which I was induced to persevere by the desire of 
comparing it with the substance discovered by myself among the products of the 
decomposition of narcotine by nitric acid, and described under the name of 
opianyl. The composition of that substance, as determined by my analyses, ap- 
proximates very closely to that of meconine; and though the formula assigned 
to the former is double that obtained by Covrrss from his analysis of the latter, 
the sole reason for adopting the higher atomic weight was, that the mode in 
which opianyl was obtained by the decomposition of narcotine, afforded satisfac- 
tory grounds for establishing its true constitution. Nor does their similarity stop 
here, for it is at once obvious, on a comparison of their properties, that they pre- 
sent many points in common, although even in this respect there are differences 
which will be afterwards particularly referred to, much too prominent and im- 
portant to be overlooked. Partly on this account, and partly because my pre- 
vious investigations of the constituents of opium had shown me that in all other 
instances the analytical results arrived at by CovERBE were very far from correct, 
I hesitated to assert their identity until I had had an opportunity of submitting 
them to an exact comparison, and of repeating the analysis of meconine. 
The experiments to be detailed in this paper prove incontestibly that they 
actually are identical; and while the composition of meconine is confirmed, the 
necessity for doubling its formula is clearly established. A careful comparison 
of the properties of the.two substances has also shown that they are perfectly 
alike; but in this respect, and especially as regards the action of various agents 
on meconine, the statements made by CovERBE require very material correction. 
~ VOL, XXI. PART I. 3G 
