Dr. Bently states, that “allowing for much of fiction, with which such a subject must ever be mixed, there is still sufficient evidence to warrant a diligent examination of the means of discriminating between real and apparent death.” (_Ency. Prac. Medicine_, vol. iii. 316.) “As respiration is a function most essential to health, and at the same time the most apparent, the cessation of it may be considered as an indication of death. But as in certain diseases and states of exhaustion it becomes very slow and feeble, and so to the casual observer to appear quite extinct, various methods have been adopted for ascertaining its existence. Thus, placing down or other light substances near the mouth or nose; laying a vessel of water on the chest, as an index of motion in that cavity; holding a mirror before the mouth, in order to condense the watery vapour of the breath; have all been proposed and employed, but they are all liable to fallacy. Down, or whatever substance is employed, may be moved by some agitation of the surrounding air; and the surface of the mirror may be apparently covered by the condensed vapour of the breath, when it is only the fluid of some exhalation from the surface of the body. We therefore agree fully with the judicious observations of Dr. Paris on this subject:—‘We feel no hesitation in asserting, that it is physiologically impossible for a human being to remain more than a few minutes in such a state of asphyxia as not to betray some sign by which a medical observer can at once recognize the existence of vitality; for if the respiration be only suspended for a short interval we may conclude that life has fled for ever. Of all the acts of animal life, this is by far the most essential and indisputable. Breath and life are very properly considered in the scriptures as convertible terms, and the same synonym, as far as we know, prevails in every language. However slow and feeble respiration may become by disease, yet it must always be perceptible, provided the naked breast and belly be exposed; for when the intercostal muscles act, the ribs are elevated, and the sternum is pushed forwards; when the diaphragm acts the abdomen swells. Now this can never escape the attentive eye; and by looking at the chest and belly we shall form a safer conclusion than by the popular methods which have been usually adopted.’” The looking-glass and the feather have been the standing test for time immemorial. When Lear enters with Cordelia dead in his arms, he says:— “I know when one is dead, and when one lives; She’s dead as earth.—Lend me a looking-glass; If that her breath will mist or stain the stone, Why, then she lives. _Kent._—Is this the promis’d end? _Edgar._—Or image of that horror? _Lear._—This feather stirs; she lives! if it be so It is a chance which does redeem all sorrows That ever I have felt.”