MEDICAL JURISPRUDENCE, or FORENSIC MEDICINE, that branch of state medicine which treats of the application of medical knowledge to certain questions of civil and criminal law. The term " medical jurisprudence," though sanctioned by long usage, is not really appropriate, since the subject is strictly a branch of medicine rather than of jurisprudence; it does not properly include sanitation or hygiene, both this and medical jurisprudence proper being distinct branches of state medicine. The connexion between medicine and the law was perceived long before medical jurisprudence was recognized, or had obtained a distinct appellation. It first took its rise in Germany, and more tardily received recognition in Great Britain. Forensic medicine, or medical jurisprudence proper as distinguished from hygiene, embraces all questions which bring the medical man into contact with the law, and embraces (i) questions affecting the civil rights of individuals, and (2) injuries to the person.
I. QUESTIONS AFFECTING THE CIVIL OR SOCIAL RIGHTS OF INDIVIDUALS i. Development of the Human Frame. The development of the physical and mental powers of the human being is a factor of great consequence in determining criminal responsibility, civil responsibility, or the power of giving validity to civil contracts, and in determining the personal identity of a living person or of a corpse. Human life is usually divided into the five periods of infancy, childhood, youth, manhood and old age. Some writers increase the number of these unnecessarily to seven periods.
Infancy is the period from birth till the first or milk set of teeth begin to be shed usually about the seventh year. During this period the body increases in size and stature more, relatively, than at any other period of existence; and the mental faculties undergo great development. The milk teeth, twenty in number, are evolved in a definite order, beginning with the central incisors at about six months, and ending with the second molars about the termination of the second year. From the size and stature of the body, the development of the teeth, and the more or less advanced state of ossification or solidification of the bony skeleton, conclusions may be drawn as to the probable age of the infant.
Childhood extends from the commencement of the shedding of the milk teeth to the age of puberty usually from the seventh to the fourteenth or fifteenth year. During this period the body expands, as well as the bony structures, without any clearly marked difference in structure being observable between the sexes except as regards the genitals, so that it is impossible to distinguish absolutely between the male and the female skeleton during this period. The milk teeth are shed, and are replaced by the second or permanent set, thirty-two in number, though these do not usually all make their appearance during childhood. Marked differences between the proclivities of the sexes are noticeable even at an early period of childhood, and long before the characteristic functions begin to be developed.
Youth is marked at its commencement by the changes which occur at puberty the development of the genitals in both sexes, the appearance of hair on the genitals, the appearance of a beard in the male, the development of the breasts in the female, the appearance of the monthly flow in the female, and the ability to secrete semen in the male. Marked mental changes now occur, and the generative functions are perfected. Youth terminates at the age of legal majority, twenty-one years, or perhaps the period ought to be extended to twenty-five years of age, as it is with some nations.
Manhood (or Womanhood) is the period of perfection of all the bodily and mental powers. It ceases in woman with the cessation of the monthly flow at about forty-five years of age; but in man it often extends to a much later period of life.
Old Age begins with the decay of the bodily and mental faculties, and is characterized by wrinkling of the skin, loss of the teeth, whitening of the hair, and feebleness of the limbs. In its later stages decay of the mental faculties, deafness, obscurity or loss of vision, and bowing of the spine are added.
2. Duration of Human Life. The chances of human life form an important subject of inquiry, and on deductions from comparisons of birth and death rates is founded the system of annuities, insurance against loss in sickness, and the insurance of lives. Since the establishment of compulsory registration of deaths, our knowledge of the ordinary and extraordinary chances of human life has been extended, and surer data are available for calculations of probabilities of life, of survivorships, and of the payments which ought to be made in benefit clubs (see INSURANCE).
3. Personal Identity. Where the identity has to be established or disproved after long absence, exposure to foreign climates and hardships, wounds, etc., the problem has often been extremely difficult. The data for identifying a person are individual and family likeness, stature, the colour of the eyes, peculiarities of garb and manner, recollection of antecedent events, but more especially marks on the persons either congenital or acquired. Such are naevi or mother's marks, scars, and disunited or badly united fractures, known to have existed upon the missing person (see IDENTIFICATION). In the case of the living, identification is more often a matter for the police officer than for the medical man. Bertillon and Gallon have each devised methods for the identification of criminals (see ANTHROPOMETRY, and FINGER- PRINTS).
4. Marriage. Under this head the medical jurist has to deal principally with the nubile age, viewed in the light of nature and according to legislative enactments, and with such physical circumstances as affect the legality of marriages, or justify divorce.
In Great Britain the age at which the sexes are first capable of *.: S pe C i es j s later than in more southern climes.
Ordinarily it does not occur before fifteen years of age for the male and fourteen for the female; exceptionally it occurs at the ages of thirteen and of twelve (or even less) respectively in the male and female. By law, nevertheless, parents and guardians may, in England at all events, forbid the marriage of young people till the age of legal majority. The only physical circumstances which in Great Britain form a bar to marriage are physical inability to consummate, and the insanity of one of the parties at the time of marriage. Both those circumstances have been pleaded and sustained in the law courts. In other countries minor physical circumstances, as disease, are held to invalidate marriage.
5. Impotence and Sterility. These are of importance in connexion with legitimacy, divorce and criminal assaults. Impotence and sterility may arise from organic or from functional causes, and may be curable or incurable. Impotence (q.v.) is taken cognisance of by the law courts as a ground of divorce, and might, of course, be urged as a defence in a case of rape. Sterility is not a ground of divorce, but might be a question of importance in cases of legitimacy.
6. Pregnancy. This subject presents one of the widest fields for medico-legal evidence. The limits of age between which it is possible, the limits of utero-gestation, and the signs of pregnancy may all in turn be the subjects of investigation.
The limits'of 'age between which pregnancy is possible are usually fixed by the appearance and cessation of the monthly flow; and these ordinarily begin about fourteen and cease at forty-five years of age. Exceptionally they appear as early as the tenth year, and may not cease till the end of the fifth decade of life. Cases, however, have occurred where a woman has conceived before menstruating; and a few doubtful cases of conception are recorded in women upwards of fifty or even sixty years of age. The general fact of pregnancy being limited by the age of puberty on the one hand and the cessation of the monthly flow or fifty-three or fifty-four years as the extreme limit of age must be accepted as the safest guide in practice.
The limits of utero-gestation are not in England fixed by legislation. The French code fixes the extreme limit of three hundred days. The ordinary period is forty weeks and a half, or two hundred and eighty-three days from the cessation of the last monthly flux. The limit of three hundred days, as fixed by the French code, is perhaps never exceeded, if ever reached. The uncertainty of females in fixing the exact date of conception has given rise to the discrepant opinions of physiologists on the subject. It is well known, however, that among the higher animals the period is not precise; and impregnation and conception need not necessarily be coincident.
The signs of pregnancy are of the utmost importance to the medical jurist. He may be called upon to pronounce upon the virtue of a female, to sustain or rebut a plea for divorce, to determine whether a capital sentence shall be carried out, or to determine whether it is probable that an heir will be born to an estate. Medical jurists classify the signs of pregnancy as uncertain or certain; it is the former which are most regarded by the public, but the latter are alone of probative value to the jurist. The usual and uncertain signs are the cessation of the monthly flow, nausea, sickness, a darkening of the areola and the formation of a secondary areola around the nipple, enlargement of the breasts, increased size of the abdomen, the formation of a tumour in the womb, quickening, and the motions of the foetus. Also uncertain are the uterine souffle, which is a peculiar soft sound heard over the abdomen and synchronous with the maternal pulse and ballottement or the examination for a floating tumour in the abdomen between the fifth and eighth months of pregnancy. The certain signs of pregnancy are the foetal limbs palpated through the abdomen by the physician, the pulsations of the foetal heart heard by means of the stethoscope, the pulsations being much quicker and not synchronous with the maternal pulse. This latter is inapplicable before the fourth month of gestation.
7. Parturition. The imminence of the process of parturition is of comparatively little interest to the medical jurist; but the signs of recent delivery are all-important. These signs are the bruised, swollen, and lacerated state of the external genitals, relaxation and dilatation of the vagina and womb, the existence of a peculiar vaginal discharge known as the lochia, a relaxed and fissured condition of the abdominal walls, a peculiar aspect of the countenance, and the distended state of the breasts due to the secretion of milk. The lochial discharge is the most characteristic sign. All the signs may disappear within ten days of delivery, though this is not usual.
Connected with parturition, the question of viability (potentiality for life) of the child is not unimportant. After the intra-uterine age of seven months is reached a child is certainly viable. The period at which the foetus becomes viable cannot be stated with certainty; but five calendar months, or one hundred and fifty days, is perhaps the nearest approximation. The viability of a child is judged by its size and weight, its general state of development; the state of the skin, hair, and nails; its strength or feebleness,the ability to cry, and its power of taking maternal nourishment. The question of viability has important bearings upon the crime of infanticide. In the case of succession to property the meaning of " born alive " is different from the meaning of the same expression as used respecting infanticide. In questions of tenancy by the curtesy (q.v.) it has been decided that any kind of motion of the child, as a twitching and tremulous motion of the lips, is sufficient evidence of live-birth. By the French code, however, no child that is born alive can inherit, unless it is born viable. As regards infanticide, proof of a conclusive separate existence of the child is demanded before live-birth is admitted.
The subject of superfoetation and super fecundation, or the possibility of two conceptions having occurred resulting in the birth of twins with a considerable intervening interval, is obscure and has given rise to much controversy. There is much, however (e.g. the existence of a double or bifid uterus), to countenance the view that a double conception is possible.
8. Monsters and Hermaphrodites. To destroy any living human birth, however unlike a human creature it may be, is to commit a crime. Blackstone states that a monster which hath not the shape of mankind hath no inheritable blood ; but the law has not defined a monster, nor what constitutes a human form. The same author states that if, in spite of deformity, the product of birth has human shape, it may be an heir. Hermaphrodites are beings with malformations of the sexual organs, simulating a double sex. Physiologists do not admit, however, the existence of true hermaphrodites with double perfect organs, capable of performing the functions of both sexes.
9. Paternity and Affiliation. These are often matters of great doubt. A considerable time may elapse between the absence or death of a father and the birth of his reputed child. As has already been said, three hundred days is the utmost limit to which physiologists would extend the period of utero-gestation. This subject involves questions respecting children born during a second marriage of the mother, posthumous children, bastardy, and alleged cases of posthumous children.
10. Presumption of Survivorship. When two or more persons perish by a common accident, when a mother and her new-born child are found dead, and in a few analogous cases, important civil rights may depend upon the question which lived the longest ; and great ingenuity has been displayed in elucidating the disputes which have arisen in the law courts in such cases.
11. Maladies exempting from Discharge of Public Duties frequently demand the attention of the medical man. He may be called upon to decide whether a man is able to undertake military or naval service, to act as a juryman without serious risk to life or health, or to attend as a witness at a trial.
12. Feigned and Simulated Diseases often require much skill and caution in order to detect the imposture.
13. The Signs of Death. The determination of the actual existence of death assumes a certain importance in tropical countries, where the necessity for speedy interment may involve a risk of burial alive. Such an accident cannot well occur where a medical man confirms the existence of death, and in the United Kingdom, where burial rarely takes place before the lapse of forty-eight hours, such changes usually occur in the body as to render any error practically impossible. Within a varying period, usually not more than twelve hours, the body becomes rigid, owing to the development of rigor mortis or post mortem rigidity. The blood, which during life is equally distributed throughout the body, gravitates to the most dependent parts and develops a discoloration of the skin which is known as post mortem lividity or post mortem staining. At a variable period of time, dependent on the cause of death, also the temperature and moisture of the air to which the body is exposed, decomposition or putrefaction sets in. These changes after death are of great importance, not only as affording certain proof of death, but also because they furnish valuable information as to the probable time at which it occurred, and from the fact that they may alter or destroy evidence as to the cause of death.
14. Insanity or Mental Alienation. A medical man may be required to give evidence in any of the law courts, civil, criminal or ecclesiastical, before commissions de lunatico inquirendo, or before a magistrate, as to the sanity or insanity of an individual; and he may have to sign certificates of unsoundness of mind with the view of providing for the safe custody and proper treatment of a lunatic. Hence he must be familiar with the chief forms of insanity (see INSANITY), and be able to distinguish and treat each of these. He will also be required to detect feigned insanity, and to examine persons charged with crime with the view of preventing real lunatics from being treated as criminals.
II. INJURIES TO THE PERSON 1. Defloration. The signs of defloration are obscure and uncertain; and it is rather by the coexistence of several of the usual marks than the existence of any one sign, that any just conclusion can be arrived at.
2. Rape. This crime consists in the carnal knowledge of a woman forcibly and against her will. The proofs of rape apart from the consistency of the woman's story, mainly depend on the presence of marks of violence, stains, etc. In all charges of rape, the woman and her assailant should be examined as soon as possible by a medical man, but such examination, it is important to remember, can only be carried out with the free consent of the party to be examined. It is to be noted that according to English law the slightest degree of penetration is sufficient to constitute the crime of rape.
3. Mutilation. This may consist in the cutting or maiming of any member; castration is the most important, and perhaps but rarely effected as a crime. Self-mutilation, giving rise to false accusations, is occasionally resorted to.
4. Criminal Abortion. This crime consists in unlawfully procuring the expulsion of the contents of the gravid uterus at any period short of full term. It must be noted that while this definition may be held to recognize the induction of premature labour by medical men in certain circumstances, yet, when the operation is necessary, a medical man should always protect himself from possible misconstruction of his action (i.e. criminal intent) by having a consultation with another practitioner. The means employed in criminal abortion to procure the desired result may be classed under three heads: (i) general violence to the body, (2) administration of drugs supposed to have abortifacient qualities, (3) instrumental interference with the contents of the uterus. Among the drugs frequently employed for the purpose, although by no means always successfully, are ergot, strong purgatives, iron, rue, pennyroyal, savin.
5. Homicide. The legal sense of the term homicide excludes such injuries as are the result of either accident or of suicide. It embraces murder or wilful homicide, manslaughter or culpable homicide, casual homicide, and justifiable homicide.
Ordinary homicide may be accomplished by several modes that may sometimes be ascertained by examination of the body, e.g. poison.
As a preliminary in all cases of homicide, it is the duty of the medical jurist in the first place to ascertain the fact of death, and to distinguish between real and apparent death; and then to determine, if possible, the period at which death took place.
Infanticide, or child murder, is by the British law treated with the same severity as the murder of an adult. Indeed infanticide as a crime distinct from murder has no legal recognition. Practically this severity defeats itself, and hence an alternative charge of concealment of birth in England, or concealment of pregnancy in Scotland, is usually preferred in such cases.
The iniquity of the old law which threw the onus of proof of stillbirth on the mother now no longer exists, and the law demands strict proof of live-birth at the hands of the prosecution. Hence the subject involves nice points of forensic medicine. The child must be proved to have arrived at the period when there was a probability of its living (proof of viability) ; and as the establishment of respiration is necessary to prove live-birth the evidences of this act must be carefully investigated. The size and position of the lungs, and the state of the vessels concerned in foetal circulation, must be carefully noted. The foetal lungs are dark, dense and liverlike in appearance and consistence, and sink when immersed in water; whilst the fully respired lungs are rosy, marbled, and soft and crepitant when handled. Minor degrees of respiration are recognized by the appearance of little groups of dilated air- vesicles, and by the fact that, although the lungs as a whole may sink in water, certain portions of them, into which respired air has penetrated, float in water even after subjection to firm pressure in the hand. Care must be taken, nevertheless, to exclude buoyancy of the lung due to putrefaction ; in this case the air may be expelled by gentle pressure, and the previously buoyant portion of lung now sinks in water. It is impossible, however, to distinguish certainly between a lung naturally inflated and one artificially insufflated.
It must be borne in mind that, although live-birth cannot be affirmed in the absence of signs of respiration, the presence of these signs is not proof of live-birth in the legal sense of the term. The law demands for live-birth a separate existence of the child after delivery ; and breathing may take place whilst the child is still either wholly or partially within the maternal passages, and in some special cases whilst still within the uterus itself.
When proofs of respiration it may be to such an extent as to leave no doubt as to live-birth have been found, the cause of death is then to be investigated. Wounds, and other forms of injury, must be sought for. There may be signs of strangulation, suffocation, puncture of the fontanelles and consequent injury to the brain, the administration of a poison, or other means of procuring death. It must be borne in mind that some of these causes may be brought about by omission, or even by accident. Thus strangulation may arise from natural and unrelieved pressure of the navel-string on the neck of the child; suffocation from immersion of the face of the child in the maternal discharges, or by pressure of clothes on the mouth. Death may result from haemorrhage through neglect to tie the navel-string, or the infant may perish from exposure to cold. In the case of exposed infants it is important to ascertain the real mother. As such exposure usually takes place soon after birth, comparison of the age of the infant with the signs of recent delivery in the suspected mother is the best method of proving the relation.
Death from Asphyxia. Among the forms of violent death due to this cause are drowning, hanging, strangulation, garotting, smothering, suffocation from choking, mechanical interference with the expansion of the chest walls, as when persons are crushed together during a panic in a fire, breathing poisonous gases, such as carbonic acid or carbonic oxide. Suicide and accidental death from these causes are still more common.
Drowning is thought to produce death occasionally by the suddenness of the shock causing suspension of the functions of circulation and respiration by shock without a struggle. The usual mode ol death appears, however, to be by the circulation of unoxygenated blood through the brain acting as a poison upon that organ; and this is attended with all the phenomena of asphyxia, as in suffocation. The phenomena attending asphyxia are as follows. As soon as the oxygen in the arterial blood, through exclusion of air, sinks below the normal, the respiratory movements grow deeper and at the same time more frequent; both the inspiratory and expiratory phases are exaggerated, the supplementary respiratory muscles are brought into play, and the breathing becomes hurried. As the blood becomes more and more venous, the respiratory movements continue to increase both in force and frequency. Very soon the expiratory movements become more marked than the inspiratory, and every muscle which can in any way assist in expiration is brought into play. The orderly expiratory movements culminate in expiratory convulsions; these violent efforts speedily exhaust the nervous system, and the convulsions suddenly cease and are followed by a period of calm. The calm is one of exhaustion ; all expiratory active movements have ceased, and all the muscles of the body are flaccid and quiet. But at long intervals lengthened deep inspiratory movements take place ; then these movements become less frequent ; the rhythm becomes irregular, so that each breath becomes a more and more prolonged gasp, which becomes at last a convulsive stretching of the whole body ; and with extended limbs and a straightened trunk, with the head thrown back, the mouth widely open, the face drawn and the nostrils dilated, the last breath is taken. The above phenomena are not all observed except in cases of sudden and entire exclusion of air from the lungs. In slow asphyxia, where the supply of air is gradually diminished (e.g. in drowning), the phenomena are fundamentally the same, but with minor differences. The appearances of the body after death from drowning are various. There may be pallor of the countenance, or this may be livid and swollen. The air passages are filled with frothy mucus, and there may be water in the stomach. The ends of the fingers are often excoriated from grasping at objects; and weeds, etc., are sometimes found grasped in the hands. The distinction between murder and suicide by drowning can rarely be made out by examination of the body alone, and is usually decided from collateral circumstances or marks of a struggle. Attention must also be paid to the existence of wounds on the body, marks of strangulation on the neck, and the like.
Hanging may result in death from asphyxia, or, as is more particularly the case in judicial hanging, some injury is inflicted on the upper portion of the spinal cord, resulting in instant death. The ordinary appearances of death from asphyxia may be found : dark fluid blood, congestion of the brain, intensely congested lungs, the right cavities of the heart full, and the left comparatively empty of blood, and general engorgement of the viscera. Ecchymosis may be found beneath the site of the cord, or a mere parchmenty appearance. There may even be no mark of the cord visible. The mark, when present, usually follows an oblique course, and is high up the neck. The fact that a body may be suspended after death, and that if this be done speedily whilst the body is still warm there may be a postmortem mark undistinguishable from the mark observed in death from hanging, must not be forgotten.
Suffocation may occur from the impaction of any substance in the glottis, or by covering up the mouth and nose. It is frequently of accidental origin, as when substances become accidentally impacted in the throat, and when infants are overlaid. The phenomena are those of pure asphyxia, which have already been detailed. On post-mortem examination the surface of the lungs is found covered with minute extravasations of blood, known as punctated ecchymosis.
Strangulation may be accomplished by drawing a cord tightly round the neck, or by forcibly compressing the windpipe (throttling). Hence there may be either a circular mark round the neck, not so oblique as after hanging, or the marks of the fingers may be found about the region of the larynx. The cartilaginous structures of the larynx and windpipe may be broken. The mark of the ligature is often low down in the neck. The signs of asphyxia are present in a marked degree.
Mephitism.ln the United Kingdom this last form of death usually results accidentally from an escape of lighting gas, the danger has been much increased in many towns owing to the addition of carburetted water-gas to the ordinary supply. Carbonic oxide gas is contained in ordinary lighting gas to the extent of about 6 to 8 %, and is extremely fatal when inhaled. Carburetted watergas contains about 28 %, and when mixed with ordinary lighting gas the percentage of carbonic oxide is thus very much increased. As a mode of assassination it is seldom employed, but is frequently resorted to on the continent of Europe by suicides, charcoal fumes being commonly used for the purpose.
6. Death from Starvation. Cases occur in which it is important to distinguish this from other modes of death. In such cases the skin becomes harsh and dry, and may acquire a peculiar odour; the subcutaneous fat disappears; the gums shrink away from the teeth; the tongue and mouth become dark-coloured and dry; the eyes are bloodshot; the intestines become thin and their coats translucent; the gall-bladder is distended. The period of total abstinence from food required to kill an adult is unknown, and greatly depends upon whether there be access to liquid. In some cases persons have been able to subsist on little or no nourishment for long periods, the body being in a state of quasi-hibernation.
7. Death from Extremes of Temperature. (i) Death from cold is not often observed in the British Isles. A portion only of the body, as the extremity of a limb, may perish from extreme cold. After the first sensation of tingling experienced on exposure to severe cold, loss of sensation supervenes, with languor and an irresistible propensity to sleep. The tendency to this forms an extreme danger in such cases. (2) Death from extreme heat usually occurs in the form of burning and scalding, attended with destruction of a large portion of the cutaneous structures. Here the cause of death is obvious. The human body is capable of exposure to very hot air as is seen in Turkish baths for a considerable period with impunity. Sunstroke is a cerebral affection brought on by too great exposure to a hot atmosphere, especially whilst undergoing fatigue.
8. Death by Lightning. Lightning or an electric current may cause instant death. No visible marks of the effects of the electric current may be left, or the body may be singed or discoloured, or the skin may be perforated at one or two spots.
9. Injuries or Wounds. These include in a medico-legal sense not only those characterized as incised, punctured, contused, lacerated, stab wounds, but also burns, injuries produced by firearms, fractures, dislocations, etc. One of the chief questions which have to be decided in all forms of violent death is whether it was the result of accident, suicide or murder. In cases of fatal wounding, among the points to be noted, which will help to decide the question, are the situation, direction and extent of the wound, the position in which the body and any weapon may be found, together with the presence and distribution of any blood marks and the signs of a struggle. In wounds caused by firearms the injury, if suicidal, is usually situated in a vital and accessible part of the body, the temple, mouth, and chest being the favourite situations; but such an injury also presents, as a rule, the characteristic appearances resulting from the discharge of the weapon close to the body, viz. besides the wound of entrance of the bullet, there are singeing of the cuticle and hair, and blackening of the area immediately surrounding the wound, from particles of unconsumed powder being driven into the skin and from the smoke of the discharge. These effects are naturally not produced when the weapon is discharged at a distance exceeding 2 or 3 ft., as usually happens in cases of homicidal shooting. They may also be wanting in undoubted suicidal wounds produced by revolvers and cartridges filled with amberite or other smokeless powders. Death from burning is generally accidental, very rarely suicidal, and when homicidal is usually employed to conceal traces of other violence inflicted upon the body. In large conflagrations death is not always due to burning. Charred bodies may be found presenting various injuries due to the fall of beams, crushing, the trampling of others trying to escape, etc., or fractures and lacerations may be due simply to the action of the heat. Death may result from such injuries, or from suffocation by the gases of combustion, before the victim is affected by the actual fire. Spontaneous combustion of the body has been stated to occur, but the evidence upon which the cases rest is not well authenticated.
Punctured wounds or stabs require minute attention; for there nave been instances in which death has been produced by an instrument so small as a pin thrust into a vital part. Wounds of the head are always dangerous, especially if the blow has been severe. The person so wounded may die without division of the skin, or fracture of the bones, as happens in what is known as concussion of the brain. Contusions which do not divide the skin may fracture the skull; or the inner table of the skull may be fractured without the outer being broken or depressed. Even wounds of the scalp may prove fatal, from inflammation extending towards the brain. Punctured wounds of the head are more dangerous than cuts, as more likely to excite fatal inflammation. When the brain and its membranes are injured, all such wounds are generally fatal. Wounds of the face or organs of sense are often dangerous, always disfiguring, and productive of serious inconvenience. Wounds of the neck are always serious whenever more than the skin is divided. The danger of opening large blood-vessels, or wounding important nerves, is imminent ; even the division of a large vein in the neck has proved immediately fatal, from the entrance of air into the vessel, and its speedy conveyance to the heart. A blow on the neck has instantly proved fatal, from injury to an important nerve, generally the pneumogastric or the sympathetic. Dislocations and fractures of the bones of the neck prove instantly fatal. Wounds of the chest are always serious when the cavity is penetrated, though persons may recover from wounds of the lungs, and have even survived for some time considerable wounds of the heart. This last is an important fact ; because we are not always to consider the spot where the body of a person killed by a wound of the heart, and apparently remaining where he fell, is found as that in which the fatal wound was inflicted. Instances have occurred of persons surviving severe wounds of the heart for several days. Broken ribs are never without danger; and the same may be said of severe contusions of the chest, from the chance of inflammation extending inwards. Wounds penetrating both sides of the chest are generally considered as fatal ; but possibly there may be recovery from such. Wounds of the abdomen, when they do not completely penetrate, may be considered as simple wounds, unless when inflicted with great force, so as to bruise the contents of the abdominal cavity; in that case they may produce death without breach of surface, from rupture of some viscus, as sometimes happens from blows or kicks upon the belly. Wounds injuring the peritoneum are highly perilous, from the risk of severe inflammation. Wounds of the stomach or intestines, or of the gallbladder, generally prove mortal, from the effusion of their contents into the peritoneal cavity producing fatal inflammation. Wounds of the liver, spleen or kidneys are generally soon mortal, from the great vascularity of those organs. Wounds of the extremities, when fatal, may generally be considered so from excessive haemorrhage, from the consequences of inflammation and gangrene, or from the shock to the system when large portions of the limb are forcibly removed, as in accidents from machinery, and in wounds from firearms.
Blood Stains. The examination of blood stains is a frequent and important operation in criminal charges. Blood stains when fresh and abundant can be recognized without difficulty, but when old, or after being acted upon by certain substances, their identity is not readily determined.
The tests which may be applied to a suspected stain consist of: (i) The microscopic test. A portion of the stain is soaked in a drop of some fluid which will soften and cause separation of the dried blood corpuscles without altering their characteristic appearance. Such fluids are solutions of glycerine and water of a specific gravity of 1028 or 30 % caustic potash. The recognition of blood corpuscles affords evidence of the nature of the stain. (2) Chemical tests, (a) Heat applied to a solution obtained by soaking some of the stained fabric in cold water. A blood solution is red, and loses its red colour on application of heat, while at the same time a buff-coloured precipitate is formed. (V) On applying a drop of freshly prepared tincture of guaiacum and then some ozonic ether or peroxide of hydrogen to the stain, a blue colour is obtained if blood be present. Many other substances, however, give the same reaction, (c) If, even to the smallest particle of dried blood, a fragment of common salt and some glacial acetic acid be added, and the latter is then heated to ebullition and allowed to evaporate away, small brown rhomboid crystals haemin crystals will be found to have formed, and they can be recognized under the microscope. (3) Spectroscopic test. A solution of blood obtained from a stain will show a spectrum having two dark bands between Fraunhofer's lines D and E ( oxyhaemoglobin). On adding ammonium sulphide to the solution the haemoglobin is reduced and only one broad dark band is seen (reduced haemoglobin). On adding caustic potash to a solution of blood, alkaline haematin is formed, and this again is transformed on the further addition of ammonium sulphide into reduced haematin or haemochromogen, which gives a very characteristic spectrum of two dark bands situated in the yellow part of the spectrum. The production of these three different spectra from a red-coloured solution is characteristic of blood. Old blood stains are insoluble in water, whereas recent stains are readily soluble in cold water, yielding a red solution. The application of hot water or washing with soap tends to fix or render blood stains insoluble. Vegetable dyes may likewise give red solutions, but they may be distinguished from blood by the addition of ammonia, which alters the colour of the former, but rather intensifies the red colour of a blood solution.
The differentiation between human blood stains and those pro- duced by the blood of other animals, more especially domestic animals, is a matter of great importance to the medical jurist. When the blood stain is fresh, measurement of the corpuscles may decide the question, but in the case of dry and old stains it is impossible to make the distinction. A method has been discovered, however, which enables the distinction to be made not only between human blood and that of other animals (with the exception of Simiidae), but also between the bloods of different animals. The method depends upon the fact that if an animal (A), such as a dog or rabbit, is inoculated with the blood or serum of another animal (B), then the blood or serum of A is found to produce a specific reaction (namely, the production of a cloudiness or precipitate) when added to a solution of the blood of a similar animal to B, and that species of animal only. If, therefore, human blood serum is injected into an animal, its blood after a time affords an " antiserum " which produces the specific reaction only in human blood solutions and not in those formed from the blood of other animals.
10. Poisoning. There is no exact definition of a poison (q.v.). Popularly, substances which destroy or endanger life when swallowed in small quantity are called poisons, but a scientific definition would also include many substances which are injurious to health in large doses or only after repeated administration, and which act not only when swallowed, but also when taken into the system through other channels, e.g. the skin or the lungs. The branch of science which relates to poisons, their nature, methods of detection, the symptoms produced by them, and treatment of poisoning, is called Toxicology, and is one of the most important subjects included under the term Medical Jurisprudence.
The medical evidence in cases of poisoning rests upon (i) the symptoms produced during life; (2) the post mortem appearances; (3) the chemical analysis and detection of the substance in the body, or in the excretions and vomited matters, or in articles of food; (4) experiments on animals in the case of certain poisons where other conclusive evidence is difficult to obtain. The treatment of cases of poisoning will vary according to the substance taken, but the general principles which should be followed are: (a) to get rid of the poison by means of the stomachpump, or by washing out the stomach with water through a soft rubber tube, or by giving an emetic such as mustard, sulphate of zinc, ipecacuanha; (b) to neutralize the poison by giving a substance which will form with it an innocuous compound (e.g. in the case of the strong acids by administering magnesia or common whiting) , or which has an opposite physiological action (e.g. atropine in opium poisoning) ; (c) to promote the elimination from the body of the poison which has been already absorbed; (d) general treatment of any dangerous symptoms which appear, as by stimulation in collapse or artificial respiration in asphyxia.
Food Poisoning (see also ADULTERATION). Foods may prove noxious from a variety of causes: (i) The presence of metallic poisons, as in peas artificially coloured with copper salts, in tinned foods from dissolved tin salts, etc. (2) The contamination of any food with the specific germs of disease, as for example, milk infected with the germ of enteric fever. (3) The presence in meat of parasites, such as the Trichina spiralis, or of disease in animals, capable of transmission to man, such as tuberculosis, or the presence of poison in the flesh of animals which have fed on substances harmless to them but poisonous to human beings. Grain may be infected with parasitic fungi of a poisonous character, as for example Claviceps purpurea, causing epidemics of ergotism. (4) Foods of various kinds may contain saprophytic bacteria which elaborate certain poisons, either before or after the food is taken. It is chiefly in relation to foodpoisoning from the last-mentioned cause that our knowledge has been increased in recent years.
Many cases of food-poisoning, previously of mysterious origin, can now be explained by the action of bacteria and the products which they give rise to tox-albumoses, ptomaines, toxins by splitting up proteid substances. It is not necessary that the food should show evident signs of putrefaction. It may not do so, and yet on being eaten produce violent symptoms of gastro-intestinal irritation almost immediately, followed by various nervous symptoms. In such cases a chemical poison, developed by putrefactive bacteria before the food was eaten, quickly acts upon the system. On the other hand, symptoms may not appear for many hours after ingestion of the food, and then come on suddenly and with great severity there has been a period of incubation. In such cases the food when swallowed has contained the bacteria, but the poisonous toxin has been elaborated by them afterwards in the system during the period preceding the onset of symptoms. In both varieties of poisoning the symptoms are similar, consisting of gastro-intestinal irritation vomiting, purging and pain in the abdomen together with great prostration, fever, muscular twitchings, disturbances of vision, delirium and coma. The varieties of meat which have most frequently given rise to poisoning (Botulismus) are pork, ham, veal, sausages, brawn, various kinds of meat pies and potted meats. Pig flesh appears to be specially liable to become infected. A point of considerable interest, which has sometimes given rise to doubt as to the poisonous character of meat in certain instances, is, that the same food may be poisonous at one time and not at another. Thus it may be harmless when freshly prepared, cause fatal effects if eaten a day or two afterwards, and shortly after that again prove perfectly innocuous. This is explained by the fact that the toxic substances take some time to develop, and after development are still further split up by the bacteria into other bodies of a harmless nature. In some fish e.g. Trachinus draco, or sea weaver the poison is a physiological product of certain glands. In others the poison is not known, as in the family Scombridae, to which the disease Kakke has been attributed. In the United Kingdom the poisonous effects produced by fish are due to bacterial agency after death, and instances have occurred from the eating of herrings, mackerel, dried salt codfish, caviare, tinned salmon and tinned sardines. Shellfish may produce poisonous effects from putrefactive changes or from the development in them (oysters and mussels) of ptomaines. Brieger discovered a ptomaine in poisonous mussels to which he gave the name mytilotoxin. It is now fully proved that oysters and mussels may become contaminated with the organism of typhoid fever if placed in specifically polluted water, and thus transmit the disease to human beings. Milk, as already stated, may be contaminated and convey the infection of scarlet fever and other diseases. It may also contain substances of bacterial origin, which are possibly the cause of infantile diarrhoea, and others, having a fatal effect upon adults. Cheese has frequently caused poisoning. Vaughan discovered a toxic substance in milk and cheese tyrotoxicon but there are other toxic substances of bacterial origin sometimes present in cheese to which poisonous effects have probably been due. Mushroom-poisoning results from the eating of poisonous fungi in mistake for the edible mushroom. The poisonous element in most cases is either muscarin contained in the fungus Amanita muscaria, or phallin in Amanita phalloides.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)