into the cerebral arteries lasts. On stopping the injection, the motions cease, and give place to the spasms of agony, and then to death.
Physiologists asked whether such a momentary resurrection of the functions of life might not he brought about in the human subject—that is, whether movement might not be excited and expression reanimated by injecting fresh blood into a head just severed from a man's body, as in M. Brown-Séquard's experiment. It was suggested to try it on the heads of decapitated criminals, but anatomical observations, particularly those of M. Charles Robin, showed that the arteries of the neck are cut by the guillotine in such a way that air penetrates and fills them. It follows that it is impracticable to inject them with blood that can produce the effects noted by M. Brown-Séquard. Indeed, we know that blood circulating in the vessels becomes frothy on contact with air, and loses fitness for its functions. M. Robin supposes that the experiment in question could be successful only if made upon the head of a man killed by a ball that should strike below the neck; in that case it would be possible to effect such a section of the arteries that no entrance of air would occur, and, if the head were separated at the place pointed out by M. Brown-Séquard, those manifestations of function remarked in the dog's head would probably be obtained by the injection of oxygenated blood. M. Brown-Séquard is convinced that they might be obtained, if certain precautions were observed, even with the head of a decapitated criminal; and, so strong is his conviction, that, when it was proposed to him to try the experiment—that is, to perform the injection of blood into the head of a person executed—he refused to do so, not choosing, as he said, to witness the tortures of this fragment of a being recalled for an instant to sensibility and life. We understand M. Brown-Séquard's scruples, but it is allowable to doubt whether he would have inflicted great suffering on the head of the subject; at most, he would only have aroused in it a degree of very dim and uncertain sensibility. This is easily explained. In life, the slightest perturbation in the cerebral circulation is enough to prevent thought and sensation utterly. Now, if a few drops of blood too much or too little in the brain of an animal in full health suffice to alter the regularity of its psychical manifestations, much more certainly will the completeness of the brain's action be deranged if it is awakened by an injection of foreign blood, a forcible entry too, which, of necessity, cannot cause the blood to circulate with suitable pressure and equipoise.
Corpse-like rigidity is one of the most characteristic phenomena of death. This is a general hardening of the muscles, so great that they lose the property of extension till even the joints cannot be bent; this phenomenon begins some hours after death. The muscles of the lower jaw are the first to stiffen; then rigidity invades in succession the abdominal muscles, those of the neck, and at last the thoracic ones. This hardening takes place through the coagulation of the half-fluid
