Page:The Harveian Oration,1902.djvu/40

 vessels. The vascular dilatation so induced is so enormous that practically the whole of the blood in the body is accumulated in the abdomen, and the animal dies by haemorrhage into its own veins. The heart may continue to beat, but to no purpose; its cavities are empty and no blood passes through it. It is, in all probability, to vaso-motor paralysis of this nature that the symptoms of surgical shock are due, as has been maintained by Lauder Brunton, Crile, and others. In this relation also the recent researches of Embley on the cause of death from chloroform are deserving of the most attentive consideration. In the early stages of chloroform inhalation the heart is weakened and more susceptible to the influence of the vagus. The inhibitory mechanism is also more excitable, so that there is thus a twofold risk of permanent inhibition of the heart, especially when the blood pressure is greatly reduced. Fortunately, in profounder anaesthesia the cardiac reflexes are almost abolished, so that in addition to its