I have not myself declined to give chloroform in any case in which a patient required to undergo a painful operation, whatever evidence of organic disease I have met with on careful examination; and although I have memoranda of upwards of four thousand cases in which I have administered this agent, I have not, as I believe, lost a patient from its use; the only person who died whilst under its influence having, in my opinion, succumbed from other causes, as I have already explained. Many writers have stated that accidents from chloroform might always be prevented by a close attention to the symptoms, or to some particular symptom, as the pulse or the breathing. Several authors have attached the utmost importance to feeling the pulse, and have considered this measure of itself sufficient to avert danger; whilst others have asserted that attention to the pulse is of no use at all. Mr. Bickersteth, for instance, writes as follows, in the article from which I previously quoted. “But the pulse should not be taken as any guide during the administration of chloroform. It should be wholly disregarded except under certain circumstances, when syncope is to be feared from loss of blood during the performance of a capital operation. The pulse is only affected secondarily in consequence of the failure of the respiration.” If the person administering chloroform was always quite sure that the vapour did not constitute more than five per cent. of the inspired air, it is quite true that the pulse might be wholly disregarded. I can never produce more certain and uniform results with chloroform than when I am giving it to small animals enclosed in glass jars, where of course the pulse cannot be felt. In surgical practice, however, where the amount of vapour in the inspired air is often very uncertain, watching the pulse may be of great service, irrespective of loss of blood; and although it will not always prevent accident, I am persuaded that it has saved many lives. In some of the accidents that have happened, the pulse has ceased suddenly, whilst it was being very carefully watched; but more usually it would show some signs of failure before entirely ceasing. In giving chloroform freely to animals from a napkin or sponge, whilst the ear or the hand was applied over the heart, I have usually found that its pulsations became embarrassed and enfeebled before they ceased; and by withdrawing the chloroform when the heart’s action first became affected, the life of the animal could often be saved. The importance of attending to the respiration of the patient has been previously noticed, and it is so obvious a symptom that it can hardly be disregarded, if anyone is watching the patient; it speaks, moreover, almost to one’s instincts, as well as to one’s medical knowledge. It is probable that no patient has been lost by disregard of the respiration, unless it be one or two whom no one was watching, or in which the head and shoulders were covered with a towel.