Remarking on such cases as these, Dr. Richardson notes that the nearest natural approach to the stage of passive efficiency is seen in hibernating animals. He states, however, that in hibernation the complete state of passive efficiency is not produced. He does not accept the opinion of those who consider that in true hibernation breathing ceases as above described. A slow respiration continues, he believes, as well as that low stage of active efficiency of circulation which we have already indicated. "The hibernating animal sleeps only; and while sleeping it consumes or wastes; and if the cold be prolonged it may die from waking." More decisive, because surer, is the evidence derived from the possibility of waking the hibernating animals by the common methods used for waking a sleeper. This certainly seems to show that animation is not positively suspended. He asks next the question whether an animal like a fish, frozen equally through all its structures, is to be regarded as actually dead in the strict sense of the word or not, seeing that if it be uniformly and equally thawed it may recover from this perfectly frozen state. "In like manner," he says, "it may be doubted whether a healthy warm-blooded animal suddenly and equally frozen through all its parts is dead, although it is not recoverable." If, as seems certainly to be the case, the animal dies because in the very act of trying to restore it some inequality in the process is almost sure to determine a fatal issue, some vital centre passing into the pectous state, the animal could not have been dead before restoration was attempted; for the dead cannot die again. Albeit, the outlook is not encouraging, at any rate so far as the use of cold alone for maintaining suspended animation in full-grown warm-blooded animals is concerned. Cold will, however, for a long time maintain ready for motion active organs locally subject to it Even after death this effect of cold "may be locally demonstrated," Dr. Richardson tells us, "and has sometimes been so demonstrated to the wonder of the world." "For instance, on January 17, in the year 1803, Aldini, the nephew of Galvani, created the greatest astonishment in London by a series of experiments which he conducted on a malefactor, twenty-six years old, named John Forster, who was executed at Newgate, and whose body, an hour after execution, was delivered over to Mr. Keate, Master of the College of Surgeons, for research. The body had been exposed for an hour to an atmosphere two degrees below freezing-point,[75] and from that cause, though Aldini does not seem to have recognised the fact, the voluntary muscles retained their irritability to such a degree that when Aldini began to pass voltaic currents through the body, some of the bystanders seem to have concluded that the unfortunate malefactor had come again to life. It is significant also that Aldini in his report says that his object was not to produce reanimation, but to obtain a