I made a chemical examination of some blood obtained from the heart and large vessels, and also of portions of the lungs and liver, but I failed to detect any trace of chloroform, although the process I employed is one by which I have very easily detected it in the bodies of small animals killed by it, and also in portions of limbs and tumours removed whilst the patients were under its influence to the usual extent. It was impossible that this patient could have breathed air strongly charged with vapour. Every one in the operating theatre was a witness that the expiratory valve of the face-piece was not, at any time, more than one-third closed, being two-thirds open. In this way no great effect of any kind can be produced, as very little of the air which the patient breathes passes through the inhaler. Mr. Potter informed me, moreover, that the patient breathed very little even of air, her breathing was so much embarrassed by her frightened condition. He was trying to calm her apprehensions at the moment when she died. The mental emotion under which the patient was labouring was, no doubt, the cause of the sudden death in this instance, as in that above referred to, which occurred at Mr. Robinson’s. The mode of dying, in the present instance, was evidently by cardiac syncope; the same mode of death, in fact, as that which is occasioned by vapour of chloroform, when not sufficiently diluted; and it is only the absolute knowledge, that any small quantity of vapour which this patient inhaled was very largely diluted with air, that enables one to decide, with confidence, that the chloroform was not the cause of death. It may be observed, however, that there was an absence of the convulsive start or spasm which occurred in all those deaths from chloroform, which took place at the beginning of the inhalation, without loss of consciousness having been first induced. The right cavities of the heart were found full of blood in this case, and it is probable that they became so much distended, as the patient was in a state of alarm, and scarcely breathing, that, in the thin and diseased state of the walls of the right ventricle, the action of the heart was arrested. Sudden death not unfrequently takes place during mental emotion, and, in many of the cases, the mode of dying is probably that just mentioned. SYMPTOMS IN THE FATAL CASES OF INHALATION OF CHLOROFORM.