175 



CHAPTER XII. 



THE ACTION OF CUTANEOUS 

 ANESTHETICS. 



Local anaesthetics given hypodermically ; cocaine, novocain, 

 eucain, stovain. Drugs applied to the unbroken skin ; opium, 

 belladonna. Counter-irritants ; the theory of their action. 



THE drugs which may be used as local anaesthetics 

 and analgesics fall into three groups. Some 

 of them are commonly given by hypodermic injection 

 beneath the skin, although they may be painted or 

 sprayed on mucous membranes with satisfactory 

 results. Here we put cocaine and its derivatives, 

 eucain (more precisely, /3-eucain lactate), novocain, 

 stovain, and tropocaine. 



In another group we place the drugs which 

 are applied to the unbroken skin in the form of 

 ointments, liniments, and plasters, including pre- 

 parations of belladonna, opium, aconite, cocaine, 

 and menthol. 



In the third group we place the drugs which 

 are not credited with any local anaesthetic action, 

 but which are classed as counter-irritants. This 

 is an immense collection ; it comprises all the 

 volatile oils, especially mustard, camphor, and tur- 

 pentine, also such substances as alcohol, iodine, 

 cantharides, and ammonia. The thermo-cautery is 

 not a drug, but its action calls for similar inter- 

 pretation. 



