78 THE HYDERABAD CHLOROFORM EXPERIMENTS 



in the later months of 1889, under the direction of Sir Lander 

 Brunt on, included 571 experiments on dogs, monkeys, 

 horses, goats, cats, and rabbits. Chloroform, ether, and the 

 A.C.E. Mixture were used. The investigations demonstrate 

 that the action of these anaesthetics is much the same on 

 man and on the animals mentioned ; that lethal doses, of 

 chloroform or ether, whether poisoning be slow or rapid, 

 usually arrest the respiratory before the cardiac action ; and 

 that the heart in uncomplicated cases stops two to six 

 minutes after respiration. Consequently, as was taught by 

 Simpson and Syme, the careful observation of the respira- 

 tion is the safeguard in the administration of anaesthetics. 

 Although the patient is safe so long as the anaesthetic vapour 

 continues to be eliminated by respiration, whenever the 

 heart stops, unless artificial respiration is had recourse to, 

 the chances of resuscitating the animal are small. This 

 important practical point was established by numerous 

 experiments. It should be noted that in the early stages 

 of chloroform administration, the heart may be inhibited 

 to a serious degree, or even cease to beat, by irritation and 

 stimulation of the vagus centre in the medulla. Thus, if 

 concentrated chloroform vapour is given at first, sudden 

 inhibition of the heart may cause death. When anaesthesia 

 is established this danger ceases. 



In the use of chloroform, and indeed of all anaesthetics, 

 in animals, these investigations emphasise the necessity of 

 constantly watching the breathing, and, moreover, ensuring 

 that nothing shall in any way interfere with it. The animal 

 should be in the recumbent position the head placed so 

 that air passes directly into the lungs ; no girths, straps, or 

 pressure must interfere with respiratory movements. 

 Monkeys, encased in plaster of Paris, or bound with ab- 

 dominal bandages, died quickly. The paralysed tongue, 

 dropping back upon the larynx of the unconscious patient, 

 may cause suffocation. Respiratory failure is also hastened 

 by having the limbs of the subject firmly bound ; while 

 struggling, or shallow, gasping breathing, by filling the lungs 

 with the volatile vapour, intensifies its effects. 



Deaths occurring during anaesthesia, both in men and 

 animals, have been ascribed to syncope, or surgical shock, 



