168 
Proceedings of Royal Society of Edinburgh. [sess. 
hydrochlorate of eucain, and solutions of the hydrochlorate of 
cocaine. 
Solutions of these salts were injected hypodermically into guinea- 
pigs of the same weight, and the results were compared. 
At first the quantity used was small, but this was gradually in- 
creased, until the lethal dose of each was accurately ascertained. 
After repeated experiments, we came to the conclusion that the 
lethal dose of eucain per kilo body-weight is ’09 gramme ; the 
lethal dose of cocaine per kilo body-weight is *068 gramme. 
We also found that the mode of death by the two substances 
varied. With the cocaine salt we observed more rotatory move- 
ments of the head, more opisthotonos, more salivation and more 
laboured breathing, than with the eucain salt. 
It was also noticed that the physiological action produced by a 
given dose of the eucain salt did not follow nearly so rapidly as 
that produced by a similar dose of the cocaine salt, under identical 
conditions with regard to the weight of the animal experimented on. 
Hence the action of eucain is slower in onset, and less in 
intensity. 
As illustrating this, we may state that *0216 gramme of eucain 
hydrochlorate dissolved in 4 c.c. of water, when injected into a 
pig weighing 570 grammes, caused only a slight weakness of the 
hind limbs ; the head was not affected. 
After the expiry of a week an injection of the same strength of 
cocaine hydrochlorate was made into the same pig. In the course 
of half an hour there were seen, in the following sequence, clench- 
ing of the teeth, rotatory movements of the head, much salivation, 
quick and shallow respirations. Shortly afterwards, convulsions 
and opisthotonos occurred, which continued for an hour, after which 
time recovery was gradual. Kecovery was, however, complete at 
the end of three hours. 
After the expiry of another week the same pig had an injection 
of ’032 gramme of hydrochlorate of eucain in 4 c.c. of water. 
In half an hour convulsions affecting the body, but with little 
disturbance to the head, commenced, and continued for 50 minutes. 
They were in no way so violent as those occasioned by *0216 
gramme of cocaine hydrochlorate ; and after the convulsions ceased, 
recovery was perfect in the course of one hour. 
