there are no physical means of distinguishing artificially inflated lungs from those that have imperfectly breathed. Experiment has repeatedly shown that when respiration has been feeble, and no artificial inflation resorted to, the air may be forced out of the lungs by moderate compression, and the portion so compressed will sink in water. If the compression be produced under water, bubbles of air may be seen to rise through the liquid. The results have been exactly the same when the lungs were inflated artificially as they were lying in the chest. (See 'Guy's Hosp. Rep.' No. V.; and for some good remarks on this subject by Christison, see Edin. Med. and Surg. Jour.' vol. 26, p. 74.)

Artificial inflation compared with natural respiration. If respiration has been perfectly established, and the lungs are well filled with air, it is impossible so to expel this air by compressing the divided portions of the organs short of such as would destroy their structure as to cause them to sink in water. If they have been only imperfectly distended by the act of respiration, they retain more or less of their foetal condition, and the air may be forced out of them to a sufficient degree to cause them to sink in water. It has been considered that in all cases of artificial inflation as distinct from the act of respiration, the air introduced could be expelled by compression of the lungs, and hence that a difference existed between lungs which had perfectly breathed and those which had been simply inflated. The author's own experience is in favour of this view. In many experi ments performed on the lungs of still-born children which had been artificially inflated, firm compression of them in a folded cloth sufficed to expel the air, which was in general only very partially distributed in isolated patches through the substance of the organs. Braxton Hicks met with a case in his practice which shows that this distinction is certainly not in all cases available, and that too exclusive a reliance upon it, without full consideration of other circumstances, may mislead a medical witness. He delivered a woman of a full-grown child; it was still-born, and there was no effort at respiration. An attempt was made to resuscitate the child, but unsuccessfully, by blowing air into the lungs through a catheter. On inspection, the lungs were observed to be of large size, but they did not present the usual appearance of lungs which had breathed. Although about three-fourths of the organs had received air by inflation, they were of a pale-fawn colour, like the thymus gland. The air was contained in the minute air-cells. They floated on water as well as all the pieces (fifteen or sixteen) into which they were divided. The editor's experience confirms this observation. When compressed between the fingers under water, small bubbles of air escaped; but no amount of compression short of destroying their structure caused these pieces to sink. A fact of this kind shows that the non-expulsion of air from lungs by compression must not be regarded as an absolute proof of respiration. It must be taken with other circumstances, e.g. absolute weight and colour, as a fact, to show that the child has either breathed, or has had its lungs perfectly inflated in a bona fide attempt to restore life after birth, either by the mother or by some person present at the birth.

In respect to lungs thus submitted to compression, the results are the same whether the child has breathed for a short or a long time after its birth, provided only the act of breathing has been complete. In one instance the author found it impossible to expel the air when the child had lived to make no more than one or two respirations, and had died before it was actually born. On this occasion it was found necessary, in order to effect delivery, to destroy the child while its head was presenting. It lived, however, a sufficient time after the protrusion of its head, with the greater part of the brain destroyed, to cry loudly for an instant. The general

WITH NATURAL RESPIRATION.

345

appearance of the body showed that it had attained to the full period of gestation. On opening the chest, the lungs were seen projecting slightly forwards over the sides of the pericardium. They were of a light-red colour, but not crepitant under the finger. They had the external physical characters which these organs are known to acquire on the first establishment of respiration; but the absence of crepitation proved that the air-cells were not completely filled. The colour of the external surface was throughout uniform, a circumstance which the author never witnessed in lungs that had been artificially inflated, except when the inflation had been carried to its fullest extent out of the body. Then, however, there is commonly distinct crepitation. When removed and placed on water, the lungs floated freely; and, on being separated, both appeared equally buoyant. Each lung was next divided into sixteen pieces, and every piece floated. In dividing them, it was observed that the colour was uniform throughout their substance, but there was no sense of crepitation under the knife; and the cells in which the air was diffused could not be seen. The pieces were then subjected to forcible compression for some time in a folded cloth. The cloth was ruptured by the force employed; yet, on removing the pieces, and placing them on water, they all continued to float. A portion of air had, undoubtedly, been forced out, but not sufficient to deprive any of them entirely of their buoyancy. The compression was carried to the farthest possible limit consistently with the preservation of the structure of the lungs. From this we learn that in some instances two or three respirations may suffice to give great buoyancy to the lungs, and so distribute the air that it cannot be forced out of the small cells by compression.

It must not, however, be supposed that, in all children which have lived but a second or two to respire, similar results will be obtained. The respiration of an instant may distend the lungs of one child, as much as respiration continued for several hours would those of another. The time which a child has survived its birth does not allow us to predict to what degree its lungs will be found distended on inspection, or what the results of experiments on these organs will be. A child may have breathed feebly, and have died either in a few minutes or hours, or not until many days have elapsed after

Fig. 155.

its birth. There is, of course, View of the Lungs imperfectly distended with air by respiration.

a The thymus.

b The heart in its pericardium.

no definite boundary between the perfect and imperfect distension of the lungs, but by the latter condition, we may understand that state of the healthy organs in which they contain only sufficient air to render them buoyant in water; and from the slight difference in their specific gravity and that of water, a small quantity will suffice for this. In these cases, the colour, volume, weight, and consistency of the lungs are scarcely changed from the foetal condition.

cc The lungs, of which the lighter portions of the engraving represent those parts which contain air.

346

ARTIFICIAL INFLATION AND IMPERFECT RESPIRATION.

The results obtained by submitting the lungs to compression in cases of respiration and artificial inflation have been very different in the hands of experimentalists. Some state that they have been able to force out the air in both instances, others in neither case. These discrepancies may depend either upon the different degrees of pressure employed, or upon the actual degree of distension of the lungs. There has been a great deal of misplaced discussion on this subject. One case should at least be adduced, in which a woman charged with child-murder has been exposed to any risk of conviction, from the admission that air cannot by compression be forced out of artificially inflated, or that it can be expelled from respired lungs. There is not a single instance in our law-records of such an objection being raised upon any but merely hypothetical grounds. If compression be trusted to as a criterion, without a proper regard to other facts, a practitioner not used to such cases may undoubtedly be easily led into error; but he may be equally deceived if he trust to a mere physical inspection of the lungs. The one means should be used to supplement the other.

Artificial inflation not distinguishable from imperfect respiration.-It must, however, be admitted, that there are no means of distinguishing feeble respiration from artificial inflation. The physical characters of the lungs will be unaltered; and compression may, in either condition, destroy their buoyancy. In a case of this kind, the only course left open to a medical witness is, to state that the evidence derived from experiments on the lungs left it uncertain whether the child in question had breathed, or had had its lungs artificially inflated. The jury will then know how to return their verdict; for it must be remembered, they have always circumstances, as well as medical opinions, to guide their judgment; and it is upon the whole, and not upon a part, of the evidence laid before them, that their verdict is founded.

The occasional difficulty of distinguishing artificial inflation from respiration, whether perfect or imperfect, has been represented as a serious objection to the employment of the hydrostatic test. Even admitting, in the few instances in which such a defence on the part of a prisoner is possible, that a practitioner is unable to distinguish one condition from the other, this becomes purely a point for the consideration of a jury: it cannot affect the general application of the hydrostatic test. The question relative to the respiration of a new-born child is not exempted from doubt; but it would be inconsistent to contend that, because certain means of investigation will not always enable us to express a positive opinion, we should never have recourse to them. No medical man in the present day would trust to the floating of the lungs as a sign of breathing, before he had ascertained that the air contained in them could not be expelled by compression. The charge against an accused party is not likely, therefore, to be sustained by medical evidence of the respiration of the child, unless the child has actually breathed; but it is possible that, owing to a want of evidence to characterize feeble respiration, a guilty person may escape upon the assumption that the lungs might have been artificially inflated.

Casper laid down what he thought to be means of distinguishing between artificial inflation and natural respiration of the lungs; and states that when we observe the following phenomena:-a sound of crepitation without any escape of bloody froth on incision, laceration of the pulmonary cells with excess of air (hyperaëria), bright cinnabar-red colour of the lungs without any marbling, and perhaps air in the (artificially inflated) stomach and intestines, we may with certainty conclude that the lungs have been artificially inflated. (Handb. of For. Med.' vol. 3, p. 68, N. S. Soc. Trans.)

In reference to this objection, there are only two cases which may give

INFANTICIDE.

DOUBTFUL CASES.

347

rise to some doubt respecting the source of the air contained in the lungs of a new-born child.

Doubtful cases.-1. In the case of a child that has not breathed, the 'lungs may be disproportionately heavy, weighing nine hundred to one thousand grains, and they may have been artificially inflated in the attempt to resuscitate it. Unless, in this case, the air was expelled by compression, an inference might be hastily drawn, that the child had probably breathed. The error could be removed only by circumstantial evidence; which, however, is generally sufficient to remove a speculative objection of this kind. But unless the foetal lungs were highly congested, diseased, or of extraordinary size, it is not likely that they would weigh so much as is here supposed. These doubtful cases may always be suspected to exist when, with considerable absolute weight, the lungs contain very little air. Let us, however, consider what would be its practical bearing on a question of child-murder, supposing the case not to be cleared up by any of the methods above suggested. 1st. The fact of respiration would not be clearly proved, because the great absolute weight of the lungs, without their structure being permeated with air, amounts to nothing. 2nd. Although the proof of respiration might not be made out, this would not show that the child was born dead; for we know that a child may live many hours, and yet no evidence of life may be derived from an examination of the lungs (p. 333, ante). 3rdly. Admitting that there was proof of the child having lived after its birth, whether there were evidence of respiration or not, the cause of death would have still to be made out; and unless this be clearly traced to the wilful act of the prisoner-proofs of which are not likely to be derived from the body of a child whose lungs she has innocently inflated -she must be acquitted. Thus, then, it is difficult to understand how this objection, on the ground of inflation, can lead to any difficulty whatever in practice. A male child, weighing upwards of twelve pounds, died during delivery in a difficult labour. It gave no signs of life when born, and there was no pulsation in the cord. Its lungs were artificially inflated in the attempt to resuscitate it. The organs weighed nine hundred and ninety-four grains. They were slightly crepitant and floated on water, but gentle pressure by the fingers caused them to sink. It was clear that the increased weight depended on their great size, and not on any change produced by respiration. They contained but a small quantity of air, which was easily expelled by pressure. In another case the child was born dead. The body was well developed, and the lungs weighed 748 grains. These organs were inflated as they were lying in the chest. On moderate compression, when divided, they immediately sank in water.

2. We will now take the converse objection. A child may live and breathe, and its lungs weigh much under the average of respired lungs, i.e. about seven hundred grains. In a case like this, unless the air resist expulsion by compression, a converse mistake might be made, and we should pronounce a child that had really breathed and survived birth to have been still-born and to have had its lungs artificially inflated. This might happen in numerous cases of imperfect respiration after birth, did we not know that the sinking of the lungs, whether containing air or not, and whether this air be expelled by compression or not, does not necessarily prove that a child was born dead. It can only show, under the most favourable circumstances, that it has either not breathed or breathed but imperfectly. The sinking of the lungs may take place in a child which has survived birth and has really been murdered; but in such a case there may be no proofs of life; and therefore a person guilty of a crime would be discharged for want of sufficient medical evidence to convict. This, however, could not justify the entire abandonment of medical evidence in all

such cases. The objection, therefore, on the ground of artificial inflation is more speculative than real. Admitting that there is no positive criterion to distinguish this condition from respiration in any degree, it is difficult to conceive a case in which the objection could be sustained; and, if' sustained, it never could lead to the inculpation of the innocent.

Improper objections to the hydrostatic test. Summary.-Medical practitioners have differed much at different times in their ideas of what the hydrostatic test was fitted to prove. The author thought that the hydrostatic test is no more capable of showing whether a child has been born alive or dead than it is of proving whether it has been murdered or has died from natural causes. The majority of those who have made experiments on this subject have only shown by the use of this and other tests, whether or not a child has breathed; they merely serve to furnish in many cases good proof of life from the state of the lungs; and it is apparent that in no case are they susceptible of doing more. And even here their utility is much restricted by numerous counteracting circumstances. (See Edin. Med. and Surg. Jour.' vol. 26, p. 365).

If asked to state in what cases the pulmonary tests are capable of assisting a medical jurist, the answer appears to be:-1st. They will clearly show that a new-born child has lived, when, during its life, it has fully and perfectly breathed. Cases of this description form a certain number of those which come before our Courts of Assize. To them the most serious objections are not applicable; and the few which might be made to the medical inferences are not difficult to answer. 2nd. They will allow a witness to say, that the lungs must have received air either by breathing or by artificial inflation. These are the cases in which a child has died soon after birth, and where the respiratory changes are but imperfectly manifested in the lungs. They probably form a large proportion of those which fall under the jurisdiction of the criminal law. It might be considered, that the qualifications in the inference here drawn would neutralize its force; but it must be remembered, that there are few instances of actual and deliberate child-murder wherein artificial inflation could become even a possible defence for an accused person. So unusual is this kind of defence, that among the numerous trials for infanticide which took place in this country for many years, the author was not able to meet with a single instance in which it was alleged as an objection to the medical evidence derived from the buoyancy of the lungs, that the prisoner had inflated them in order to resuscitate her child. The reason is obvious: had such a defence been attempted, the whole of the circumstantial evidence would at once have set it aside. When in the suspected murder of an adult, a medical man swears that a fatal wound was such that the deceased might have inflicted it on himself, or that the prisoner might have produced it, he is placing the jury in a position very similar to that in which he places them in a case of child-murder, when he says that the child might have breathed, or its lungs might have been artificially inflated. How would a jury decide in such a case? Assuredly, by connecting certain facts with which a medical witness is not concerned, but which may satisfactorily supply the place of what is deficient in his evidence. It is for them to consider whether an accused party was or was not likely, under the particular circumstances of the case, to have resorted to artificial inflation. It has been suggested that some person might inflate the lungs of a dead child, in order to raise a charge of murder against its mother; but this suggestion presupposes, on the part of a criminal, a knowledge of the difficulties of medical jurisprudence: and such a case is very unlikely to present itself.

The hydrostatic test ought not, therefore, to be lightly condemned,