1 56 DRS CRUM BROWN AND FRASER ON THE CONNECTION BETWEEN 



pentatomic ; it easily loses the hydrogen and chlorine it has acquired, and returns 

 to the triatomic state. The action of alkalies, or, in many cases, even of alka- 

 line carbonates, is sufficient to effect this, and reprecipitate the alkaloid. It is 

 obvious, therefore, that the chemical addition of an acid does not satisfy the 

 third condition mentioned above, for it is certain that the addition can be per- 

 formed in the stomach, which is acid, and very probable that it may be reversed 

 in the blood and other alkaline fluids of the body. But if, instead of an acid, we 

 make use of such a substance as iodide of methyl, we find that while the 

 triatomic nitrogen takes up CH 3 and I, and becomes pentatomic (just as in the 

 former case it took up H and CI), it does not lose these newly-acquired atoms 

 when the substance is treated with alkalies, but remains pentatomic even when 

 subjected to attacks more violent than any to which it can be exposed in the 

 animal system. This operation, the addition of iodide of methyl to nitrile bases, 

 satisfies the first condition, for we know precisely what change of structure is 

 produced. It satisfies the second, for the change of structure is the same in all 

 nitrile bases ; and the change of iiotential, as far as can be judged from a very 

 rough estimate of the heat produced by the change, and from the general character 

 of the substances produced, is not very different in different cases. It satisfies the 

 third, as we have seen above ; and as the iodides of the compound ammoniums 

 thus formed from the alkaloids are all tolerably soluble in warm water, and can 

 easily be transformed into other salts very readily soluble, it satisfies the fourth 

 condition ; and the observations of Stahlschmiut show, and the sequel of this 

 paper will further prove, that it satisfies the fifth. 



It deserves to be noted that this operation only removes the condensation of 

 the typical nitrogen (that is, of one atom of nitrogen for each molecule of a 

 mono-basic acid that the alkaloid can saturate), and leaves any other condensa- 

 tion which may exist in the substance unaffected ; so that even if physiological 

 action should depend upon condensation, it would be unreasonable to expect 

 $ + A $ to be in all cases zero, that is, that the new bodies should be quite 

 inert. 



In the present paper we communicate the results of the application of the 

 method described to strychnia, brucia, thebaia, codeia, morphia, and nicotia. In 

 each case we shall first describe the action of the alkaloid itself, then give the 

 method of preparing the derived substances, and describe their physical char- 

 acters, and, with some detail, their physiological action. Our investigation of the 

 physiological action of these substances has been chiefly directed to the deter- 

 mination of their poisonous activity, and of the most prominent differences 

 between the nature of their action and that of the alkaloids from which they are 

 derived. 



