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XII. — Researches on some of the Crystalline Constituents of Opium. Second Series. 

 By Thomas Anderson, M.D., Regius Professor of Chemistry in the University 

 of Glasgow. 



J o v 



(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 

 Couerbe 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 Couerbe 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 Couerbe 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 Couerbe require very material correction. 



VOL. XXI. PART I. 3 G 



