USES OF ANESTHETICS 79 



and in order to elucidate this matter numerous experiments 

 were made on dogs and monkeys. When full anaesthesia 

 was produced, teeth were extracted, nails evoluted, incisions 

 made into the abdomen, portions of intestine ligatured, and 

 the testicles sharply struck ; but in no case was any marked 

 effect produced on the heart action. To test the effect of 

 chloroform on animals with enfeebled heart, dogs and 

 monkeys were fasted, others were freely bled, while others 

 were given grain doses of phosphorus during several days, 

 in order to produce fatty degeneration of the heart muscle. 

 But neither syncope nor heart-shock was observable when 

 these subjects were deeply chloroformed ; respiratory failure 

 invariably preceded cardiac failure ; and when breathing 

 was stopped by full doses, the animals, like others in perfect 

 health, were restored by artificial respiration. Occasion- 

 ally, however, as mentioned above, death occurs suddenly 

 through inhibition of the heart by vagal stimulation during 

 the earlier stages ; and experiments prove that healthy 

 horses can be killed in a few minutes by rapid administra- 

 tion of concentrated chloroform vapour. 



The post-mortem appearances of animals dying under 

 anaesthesia consist in general congestion of the lungs, liver, 

 kidneys, and spleen, which is also puckered, and two or 

 three times larger than usual. The left heart may be empty 

 and the right heart distended with blood. 



Anaesthetics are used in painful, delicate, or protracted 

 operations, as in castration, neurectomy , excisions of portions 

 of the hoof, and other operations on the foot ; reduction of 

 herniae, and removal of tumours ; extraction of firmly-fixed 

 teeth, especially in dogs and cats ; in tetanus, and strych- 

 nine poisoning ; in difficult parturition, especially in the 

 mare ; and in destroying injured, useless, or old animals. 



Administration to horses may be made while the animal 

 is standing, but more safely and effectually when he is cast 

 and secured. A sponge or piece of lint, saturated with the 

 anaesthetic, is placed in a tolerably close-fitting nose-bag, 

 which is adjusted to the head. Inhalers, bags or muzzles 

 for the purpose have been designed by Cox, and other 

 veterinary surgeons. Many practitioners, when the horse 

 is cast, place the lint, moistened with chloroform, over one 



