But next let us consider what science has to say as to the artificial suspension of vitality. In Dr. Richardson's paper on this subject there is much which seems almost as surprising as anything in the Australian story. Indeed, he seems scarcely to have felt assured that that story really was a hoax. "The statements," he says, "which, under the head of 'A Wonderful Discovery,' are copied from the Brisbane Courier, seem greatly to have astonished the reading public. To what extent the statements are true or untrue it is impossible to say. The whole may be a cleverly-written fiction, and certain of the words and names used seem, according to some readers, to suggest that view; but be this so or not, I wish to indicate that some part at all events of what is stated might be true, and is certainly within the range of possibility." "The discovery," he proceeds, "which is described in the communication under notice, is not in principle new; on the subject of suspension of animation I have myself been making experimental inquiries for twenty-five years at least, and have communicated to the scientific world many essays, lectures, and demonstrations, relating to it. I have twice read papers bearing on this inquiry to the Royal Society, once to the British Association for the Advancement of Science, two or three times in my lectures on Experimental and Practical Medicine, and published one in Nature. In respect to the particular point of the preservation of animal bodies for food, I dwelt on this topic in the lectures delivered before the Society of Arts, in April and May of last year (1878), explaining very definitely that the course of research in the direction of preservation must ultimately lead to a process by which we should keep the structures of animals in a form of suspended molecular life." In other words, Dr. Richardson had indicated the possibility of doing precisely that which would have constituted the chief value of the Australian discovery, if this had been real.
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. She tried to cry, but her mind was without power, and could not act on the body. It was equally impossible to her to stretch out her arms or to open her eyes or to cry, although she continually endeavoured to do so. The internal anguish of her mind was, however, at its utmost height when the funeral hymns began to be sung and when the lid of the coffin was about to be nailed on. The thought that she was to be buried alive was the first one which gave activity to her mind, and caused it to operate on her corporeal frame. Just as the people were about to nail on the lid, a kind of perspiration was observed to appear on the surface of the body. It grew greater every moment, and at last a kind of convulsive motion was observed in the hands and feet of the corpse. A few minutes after, during which fresh signs of returning life appeared, she at once opened her eyes, and uttered a most pitiable shriek." In this case it was considered that the state of trance had been brought about by the excessive contractile action of the nervous centres. St. Augustine, by the way, remarks in his "De Civitate Dei" on the case of a certain priest called Restitutus (appropriately enough), who could when he wished withdraw himself from life in such sort that he did not feel when twitched or stung, but might even be burned without suffering pain except afterwards from the wound so produced. Not only did he not struggle or even move, but like a dead person he did not breathe, yet afterwards he said that he could hear the voices of those around him (if they spoke loudly) as if from a great distance (de longinquo).
To return, however, to Dr. Richardson's discussion of the artificial suspension of active life.
He recognises three degrees of muscular irritability, to which he has given the names of active efficient, passive efficient, and negative,—though doubtless he would recognize the probability that the line separating the first from the second may not always be easily traced, and that, though there is a most definite distinction between the second and the third, the actual position of the boundary line has not as yet been determined. In other words, so far as the first and second states are concerned, there are not two degrees only, but many. As regards the third or negative state, which is only another way of describing death, there is, of course, only one degree, though the evidence as to the existence of this state may be more or less complete and obvious. Dr. Richardson defines the active efficient state of muscular irritability as that "represented in the ordinary living muscle in which the heart is working at full tension, and all parts of the body are thoroughly supplied with blood, with perfection of consciousness in waking hours, and, in a word, full life." The second, or passive efficient state, "is represented in suspended animation, in which the heart is working regularly but at low tension, supplying the muscles and other parts with sufficient blood to maintain the molecular life, but no more." The third of these states—the negative—"is represented when there is no motion whatever of blood through the body, as in an animal entirely frozen."
With the first and third of these states I have in reality nothing to do, unless indeed it could be shown that the third or negative state can be produced without causing death. Perhaps in assuming, as I did above, that this state is identical with the state of the dead, I was, in fact, assuming what science has yet to demonstrate. I may at any rate, however, say without fear of valid contradiction, that science has as yet never succeeded in showing that this negative state may be attained even for a moment without death ensuing; and the probability (almost amounting to certainty) is that death and this change of state have in every instance been simultaneous. Dr. Richardson speaks of the second stage as that in which animation is usually suspended; but he does not show that the third stage can even possibly be attained without death.
The second stage, or stage of passive efficiency, closely resembles the third, "but differs from it in that, under favouring circumstances, the whole of the phenomena of the active efficient stage may be perfectly resumed, the heart suddenly enlarging in volume from its filling with blood, and reanimating the whole organism by the force of its renewed stroke in full tension. So far as we have yet proceeded," continues Dr. Richardson, "the whole phenomena of restoration from death are accomplished during this stage;" meaning, it would seem, that in all instances of restoration the restoration has been from the second, never from the third stage. "To those who are not accustomed to see them they are no doubt very wonderful, looking like veritable restorations from death. They surprise even medical men the first time they are witnessed by them." He gives an interesting illustration. At a meeting of the British Medical Association at Leeds, "a member of the Association was showing to a large audience the action of nitrous oxide gas, using a rabbit as the subject of his demonstration. The animal was removed from the narcotizing chamber a little too late, for it had ceased to breathe, and it was placed on the table to all appearance dead." "At this stage," he proceeds, "I went to the table, and by use of a small pair of double-acting bellows restored respiration. In about four minutes there was revival of active irritability in the abdominal muscles, and two minutes later the animal leaped again into life, as if it had merely been asleep. There was nothing remarkable in the fact; but it excited, even in so cultivated an audience as was then present, the liveliest surprise."
But when we learn the condition necessary that a body which has once been reduced to the state of passive efficiency should be restored to active life, we recognise that even when science has learned how to reduce vitality to a minimum without destroying it, few will care to risk the process, either in their own persons or in the case of those dear to them. Besides the condition already indicated, that the muscular irritability and the nervous excitation must be simultaneously and equally reduced, it is essential that the blood, the muscular fluid, and the nervous fluid should all three remain in what Dr. Richardson calls the aqueous condition, and not become what he calls pectous, a word which we must understand to bear the same relation to the word solid or crystalline that the word "aqueous," as used by Dr. Richardson, bears to the word watery. If all three fluids remain in the aqueous condition, "the period during which life may be restored is left undefined. It may be a very long period, including weeks, and possibly months, granting that decomposition of the tissues is not established; and even after a limited process of decomposition, there may be renewal of life in cold-blooded animals. But if pectous change begins in any one of the structures I have named, it extends like a crystallization quickly through all the structures, and thereupon recovery is impossible, for the change in one of the parts is sufficient to prevent the restoration of all. Thus the heart may be beating, but the blood being pectous it beats in vain; or the heart may beat and the blood may flow, but the voluntary muscles being pectous the circulating action is vain; or the heart may beat, the blood may flow, and the muscles may remain in the aqueous condition, but the nerves being pectous the circulating action is in vain; or sometimes the heart may come to rest, and the other parts may remain susceptible, but the motion of the heart and blood not being present to quicken them into activity, their life is in vain." Add to this, that the restoration of the motor forces, of the muscular irritability, and of the nervous excitation, must be as simultaneous and as equal as their reduction had been, and we begin to recognise decided objections to the too frequent suspension of animation, even when the most perfect artificial means have been devised for bringing about that interesting result.
Although, however, we may not feel encouraged to believe that many will care to have experiments tried on themselves in this direction, we may still examine with interest the results of experimental research and experience. These agree in showing that there are means by which active life may be suspended, while at the same time the aqueous condition of the fluids mentioned above (the blood, the muscular fluid, and the nervous fluid, the two latter of which are for convenience called the colloidal animal fluids, and are derived from the blood) is retained.
The first and in some respects the most efficient of these means is cold. The blood and the colloidal fluids remain in the aqueous condition when the body is exposed to cold at freezing-point. "At this same point all vital acts, excepting perhaps the motion of the heart" (it is Dr. Richardson, be it remembered, who thus uses the significant word "perhaps"), "may be temporarily arrested in an animal, and then some animals may continue apparently dead for long intervals of time, and may yet return to life under conditions favourable to recovery." Dr. Richardson gives a singular illustration of this, describing an experiment which must have appeared even more surprising to those who witnessed it than that in which the rabbit was restored to life. "In one of my lectures on death from cold," he says, "which I delivered in the winter session of 1867, some fish which during a hard frost had been frozen in a tank at Newcastle-on-Tyne, were sent up to me by rail. They were produced in the completely frozen state at the lecture, and by careful thawing many of them were restored to perfect life. At my Croomian lecture on muscular irritability after systemic death, a similar fact was illustrated from frogs." It would appear, indeed, that so far as cold-blooded animals are concerned, there is no recognisable limit to the time during which they may remain thus frozen yet afterwards recover. But, even in their case, much skill is required to make the recovery sure. "If in thawing them the utmost care is not taken to thaw gradually, and at a temperature always below the natural temperature of the living animal, the fluids will pass from the frozen state through the aqueous into the pectous so rapidly that death from pectous change will be pronounced without perceiving any intermediate or life stage at all." Naturally it is much more difficult to restore life in the case of warm-blooded animals. Indeed, Dr. Richardson remarks, that in the case of the more complex and differently shielded organs of warm-blooded animals, it is next to impossible to thaw equally and simultaneously all the colloidal fluids. "In very young animals it can be done. Young kittens, a day or two old, that have been drowned in ice-cold water, will recover after two hours' immersion almost to a certainty, if brought into dry air at a temperature of 98 degrees Fahrenheit. The gentlest motion of the body will be sufficient to re-start the respiration, and therewith the life."
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.