ALKALOIDAL TOXINS. 5 



more to the impurities present than to the bases 

 themselves. 



The physiological action of these bases varies 

 greatly; in some the action is an extremely toxic 

 one, as in the case of neurine and muscarine, 

 which are true ptomaines; there are others, such 

 as cadaverine and putrescine, which are quite 

 innocuous. The physiological action of these bases, 

 like that of the true toxins, is studied by making 

 hypodermic injections of solutions of the bases in 

 healthy animals, such as guinea-pigs, rabbits, and 

 dogs. 



In animals, the principal phenomena observed by 

 Selmi to follow the injection of the substances are 

 the following: At first dilatation of the pupil, then 

 constriction; tetanic convulsions, soon followed by 

 muscular relaxation, and retardation, rarely acceler- 

 ation, of heart-beat ; absolute loss of cutaneous sen- 

 sibility; loss of muscular contractility; paralysis of 

 the vasomotors ; greatly retarded respiration ; stupor, 

 followed by death with the heart in systole. 



It must be observed that in a number of cases 

 where toxic researches had been made in the past, 

 these bases had been mistaken for poisons which 

 were believed to have been introduced into the 

 organism with criminal intent. No one will ever 

 know how many have fallen victims in the past to 

 ignorance regarding the cellular mechanism! 



The extraction of these bases is a tedious and 



