ANESTHESIA. 
315 
So much for the chloroforming of large animals. As for 
dogs, I do not as a rule use pure chloroform, as it is dangerous, 
and requires careful watching. I prefer the A.C.E. mixture, 
and find it quite satisfactory. The only appliance needed is a 
towel folded into a cone shape, with a small sponge fastened in 
the bottom of it. It is a very easy matter to give a dog an 
overdose of chloroform, and in such a case the quickest way to 
restore animation is to take the dog by the hind legs and swing 
him, head downwards, from side to side until he revives. 
Local anaesthesia is a more recent discovery than general 
anaesthesia, and has lately enlarged its sphere of usefulness 
enormously, owing to the discovery of cocaine. At first the only 
way of producing local anaesthesia was by freezing the part by 
ether spray, or to render it numb by the use of ice and salt. At 
present the injection of cocaine solution is the method chiefly 
employed, and it is hardly possible to overestimate the value of 
this drug to the general practitioner. Recently a new method of 
employing it has been discovered, and promises to be of great 
usefulness. It is called cataphoresis, and is a process of driving 
the cocaine into the tissues by means of an electric current. It 
has already proved of great assistance in dentistry, and will 
probably be found useful, too, in our profession. 
Cocaine is generally injected into the subcutaneous tissue 
with a hypodermic syringe. This should be kept clean, and not 
used for exploring pus cavities, or an abscess may form at the 
seat of puncture. The syringe should be large enough to hold 
two drachms of fluid, and it is an advantage to have the needle 
coupled on to the syringe simply by pushing one into the other. 
This will save many breakages of needles, as the needle can be 
inserted first and the syringe coupled on to it afterwards. 
The solution of cocaine should always be freshly made, and 
only boiled and filtered water used for the purpose. When co¬ 
caine was first introduced, it was used in lo and even 20 per 
cent, solutions, as it was thought that the stronger it was, the 
more powerful would be its effect. It is now found that these 
concentrated solutions are unnecessary, and that a 4 per cent. 
