28 ACTION OF HALOGEN COMPOUNDS OF ETHYL AND AMYL 
so in reality, my attempts at forming corresponding compounds with some other 
alkaline principles of opium having been as yet unsuccessful. Another order of 
plants, however, has furnished me a base, strychnine, which seems in this respect 
similarly constituted with morphia and codeine, inasmuch as, under the same 
circumstances, it yielded a new combination, whose stability in the free state, and 
in some of its salts, caused it to afford more decided results than I was able to 
obtain with the analogous products from these alkaloids. 
This investigation was pursued in the laboratory of Professor ANDERSON, in 
the University of Glasgow, to whom my cordial thanks are due for the interest 
he took in its progress, and, among other things, for the facilities he afforded me 
in placing at my disposal specimens of subjects for experiment. 
In describing the individual re-actions, salts, &c., I have preferred giving them, 
as nearly as is consistent with clearness, in the order in which they were inves- 
tigated. 
Behaviour of Papaverine with Iodide of Ethyl. 
Hydriodate of Papaverine—Next to morphia and codeine, papaverine is the 
opium alkaloid possessing the most marked characters, and highly basic properties, 
and as I was acquainted with the beautiful substitution products it yielded to 
Professor ANDERSON, of which an account has been given to this Society,* I chose 
it as the subject for further experiment. Accordingly, some of the base, in small 
crystals, was placed in a tube, spirit of wine poured on it, and iodide of ethyl 
added ; a great part of the crystals was seen to disappear immediately, and when 
the sealed tube was placed in boiling water, solution became rapidly complete. 
The clear fluid was allowed to boil about half an hour, but no solid made its ap- 
pearance, either during the continuance of the heat, or upon the subsequent cool- 
ing and standing of the vessel. The solution was distilled finally in a flask to a 
very small bulk, and the syrup which remained soon solidified into a crystalline 
mass; this was found to be perfectly soluble in hot water—papaverine itself being 
insoluble—and in spirit of wine; but, from peculiarities to be mentioned presently, 
absolute alcohol was preferred as a solvent. From a concentrated hot solution 
in this menstruum, the new product was obtained, on cooling, in rhombic crystals, 
a portion of which, as they proved to be an hydriodate, was submitted to ana- 
lysis in the ordinary way, with the following result :— 
5:558 grains, dried in vacuo, gave 
2780 ... iodide of silver, 
which gives a percentage of iodine of 27:02, and 27:21 is the theoretical calcula- 
tion corresponding to the anhydrous hydriodate of papaverine, whose formula is 
C,, H,, NO, HI. 
* Trans. Roy. Soc. Edin., vol. xxi., part 1. 
