242 THE ACTION OF 



aesthesiometer, a wool pencil, etc., was also used. 

 In testing the sensibility of the tongue, we used the 

 faradic pain test as described above ; we examined 

 thermal discrimination by applying warm metal 

 points at various temperatures ; we used the aesthesio- 

 meter, and studied the effect of the drugs on taste. 



Judged by these standards, the^^various drugs fared 

 as follows : — 



Opium. — A 5 per cent solution of morphine 

 tartrate in water had no effect on skin or tongue. 



Belladonna. — Very strong liniments had no anaes- 

 thetic effect. Indeed, if they had, the drug could 

 be used instead of cocaine for eye surgery. The only 

 sign we could obtain was diminution of sweating 

 over the skin area treated. There was no flushing 

 or blanching of the skin or mucous membrane. 



Aconite. — Neither the B.P. liniment nor ointment 

 had any effect on the skin. Solutions produced 

 tingling of the tongue, but we were not quite confident 

 whether there was or was not a little reduction in 

 sensibility. 



Cocaine. — Strong ointments and alcohoHc solutions 

 had no effect on the unbroken skin. Of course, if 

 the skin is damaged, the effect is marked. A lo per 

 cent solution apphed to the tongue produced con- 

 siderable reduction of sensibility, by all our tests. 



Menthol produces a curious stimulation of the 

 nerve-endings which detect cold, as is weU known. 

 A discussion of its other actions would lead us too 

 far, but any anaesthetic effect is purely that of a 

 counter-irritant. 



Catholic Acid rather increases the sensitiveness of 



