8 



Dr. C. R. A. Wright's Contributions to the [Nov. 16, 



and there may be considerable likelihood that conditions explained or 

 rendered probable under the statical theory would have some correspond- 

 ing explanation or confirmation under any true theory by which the 

 statical might come to be superseded. With a view to brevity, how- 

 ever, and to the avoidance of putting forward speculations perhaps partly 

 rash, though, I think, not devoid of real significance, I shall not at pre- 

 sent enter on details of these considerations, but shall leave them with 

 merely the slight suggestion now offered, and with the suggestion men- 

 tioned in an earlier part of the present paper, of the question whether 

 in an extremely thin lamina of gradual transition from a liquid to its own 

 gas, at their visible face of demarcation, conditions may not exist in a 

 stable state having a correspondence with the unstable conditions here 

 theoretically conceived. 



II. " Contributions to the History of the Opium Alkaloids. — Part 

 III." By C. It. A. Wright, D.Sc, Lecturer on Chemistry in St. 

 Mary's Hospital Medical School. Communicated by Dr. H. E. 

 Roscoe. Received July 21, 1871. 



§ 1 . Action of Hydriodic Acid on Codeia in presence of Phosphorus. 



In Parts I. and II. of these researches the action of hydrobromic acid 

 on codeia and its derivatives has been partially investigated ; and as the 

 action of this acid appears to be in some respects similar to, but in others 

 different from, that of hydrochloric acid, it appeared to be of interest to 

 examine the action of hydriodic acid also. 



Some preliminary experiments on this subject made two or three years 

 ago in conjunction with the late Dr. A. Matthiessen, showed that when 

 codeia is boiled with a large excess of strong hydriodic acid, no appreciable 

 quantity of methyl iodide is evolved even after some hours' treatment ; a 

 brown tarry mass containing much free iodine was produced, but at the 

 time nothing fit for analysis was obtained from this ; since then, Dr. 

 Matthiessen and Mr. Burnside* have corroborated the non-formation of 

 methyl iodide under these circumstances. 



If, however, phosphorus be added simultaneously with the hydriodic 

 acid, so as to prevent the accumulation of free iodine, methyl iodide is 

 evolved at 100° and upwards in quantity close upon that required for 

 the equation 



Codeia. Morphia. 



C 18 H 21 N0 3 +HI= CH 3 1 + 0„ H 19 N0 3 ; 



hitherto, however, no body of this latter formula has been isolated from 

 the products of the reaction, the substances ultimately formed being derived 

 from a base containing H 2 more than morphia. 



The hydriodic acid was obtained in the first instance by the action of 



* Proc. Eoy. Soc. vol.xix. p. 71. 



