Let us next consider what is known respecting the possibility of suspending a conscious and active life. This is first stated in general terms by Dr. Richardson, as follows:--"If an animal perfectly free from disease be subjected to the action of some chemical agents or physical agencies which have the property of reducing to the extremest limit the motor forces of the body, the muscular irritability, and the nervous stimulus to muscular action, and if the suspension of the muscular irritability and of the nervous excitation be made at once and equally, the body even of a warm-blooded animal may be brought down to a condition so closely resembling death, that the most careful examination may fail to detect any signs of life." This general statement must be carefully studied if the reader desires thoroughly to understand at once the power and the limits of the power of science in this direction. The motor forces, the muscular irritability, and the nervous stimulus to muscular action, can be reduced to a certain extent without destroying life, but not absolutely without destroying life. The reduction of the muscular irritability must be made at once and equally; if the muscular irritability is reduced to its lowest limit while the nervous excitation remains unaltered, or is less reduced, death ensues; and _vice versâ_, if the nervous excitation is reduced to its lowest limits while the muscular irritability remains unaltered, or is little reduced, death equally follows. Then it is to be noticed that though when the state of seeming death is brought about, the most careful examination may fail to detect any signs of life, it does not follow that science may not find perfectly sure means of detecting cases where life still exists but is at its very lowest. Of course all the ordinary tests, in which so many place complete reliance--a mirror placed close to the mouth, a finger on the pulse, hand, or ear applied to the breast[74] over the heart, and so forth--would be utterly inadequate, in such a case, to reveal any signs of life. That doctors have been deceived by cases of suspended vitality not artificially produced, but presenting similar phenomena, is well known. A case in point may not be out of place here, as illustrating well certain features of suspended animation, and showing the possibility that in _some_ cases consciousness may remain, even when the most careful examination detects no traces of life. The case is described by Dr. Alexander Crichton, in his "Inquiry into the Nature and Origin of Mental Derangement." "A young lady, who had seemed gradually to sink until she died, had been placed in her coffin, careful scrutiny revealing no signs of vitality. On the day appointed for her funeral, several hymns were sung before her door. She was conscious of all that happened around her, and heard her friends lamenting her death. She felt them put on the dead-clothes, and lay her in the coffin, which produced an indescribable mental anxiety.