ON SOME VEGETABLE ALKALOIDS. 29 



I shall shew presently, from an analysis and description of the base obtained 

 from this salt, that there can be no doubt of its real nature ; so that, under these 

 circumstances, papaverine behaves in a manner similar to that shewn before * to 

 be the case when hydrated morphia is placed in contact with chloride of amyl, it 

 forms a salt, namely, with the halogen of the ether compound, while no doubt the 

 corresponding alcohol is simultaneously generated by the agency of the elements 

 of water, as in the equation — 



C 40 H 21 N0 8 + C 4 H 5 I + 2 HO = C 40 H„ N0 8 HI + C 4 H 6 2 ; 



this, at least, seems the most obvious explanation of the change when water is 

 present. To determine if the formation of the salt were really due to the agency 

 of water, I repeated the experiment with absolute alcohol in place of rectified 

 spirit, and the papaverine was dried at 212°, to remove accidental moisture, its 

 crystals containing no water of combination. In this case, also, the hydriodate 

 was formed from part of the alkaloid, the rest remaining unaltered. The iodide 

 of ethyl had been distilled from chloride of calcium, and I should think could 

 furnish, at the most, but a minute quantity of water ; and it is not easy to see how 

 the reaction is brought about under these circumstances, unless it be assumed 

 that it occurs with the formation of ether. The detection of this substance would 

 not be readily effected upon the small scale upon which I worked, and I there- 

 fore only throw out the following equation as a possible explanation of the re- 

 action — 



C 40 H 21 N0 8 + C 4 H 5 I + C 4 H 6 2 = C 40 H 21 N0 8 HI + 2 C 4 H 5 O. 



As no account has yet been given of the hydriodate of papaverine, a short 

 description of it may be subjoined. The salt is extremely soluble in boiling 

 water, and the moment the heat is withdrawn from a strong solution, the fluid 

 assumes a milky appearance, and an oil is soon deposited, which, after some 

 hours, passes into the form of stellate colourless needles ; it is also soluble in 

 spirits of wine, but in absolute alcohol it dissolves with far less facility, and it re- 

 quires protracted boiling, when the salt has once taken on the crystalline condi- 

 tion, to obtain perfect solution with this menstruum. The hot liquid deposits the 

 salt rapidly, as it cools, in colourless rhombic crystals. When exposed to a tem- 

 perature of 212° Fahrenheit, in a dry state, the hydriodate of papaverine assumes 

 a brown tint, loses slightly in weight, and is found to have undergone some de- 

 composition, as it no longer dissolves completely in hot water, but leaves a brown 

 resinous matter. 



By addition of ammonia to the mother liquors of the salt which had been 

 analysed, a white crystalline precipitate was obtained; this was recrystallized 

 from dilute spirit, and burnt with chromate of lead :— 



* Quart. Journ. Chem. Soc, vol. vi. 



