778 MEDICAL JURISPRUDENCE MEDICAL JURISPRUDENCE, or, as it is now more usually termed, FOEENSIC MEDICINE, is that branch of state medicine which treats of the application of medical knowledge to the purposes of the law. The term medical jurisprudence, though sanctioned by long usage, is not an appropriate one; since the subject is, strictly speaking, a branch of medicine rather than of jurisprudence ; it does not properly include sanitation or HYGIENE (q.v.), 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 sub sequently, but more tardily, received recognition in Great Britain. Forensic medicine, or medical jurisprudence proper as distinguished from hygiene, embraces all those questions which bring the medical man into contact with the law, nnd embraces (1) questions affecting the civil rights of individuals, and (2) injuries to the person. I. QUESTIONS AFFECTING THE CIVIL OR SOCIAL RIGHTS OF INDIVIDUALS. 1. Development of the Human Frame. The develop ment of the physical and mental powers of the human being is a matter of the highest importance, and 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 di vided into the five periods of infancy, childhood, youth, manhood, and old age. Some writers increase the number of these, unnecessarily, to seven periods, without any prac tical advantage. 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 exist ence ; and the mental faculties undergo great develop ment. 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 shed ding 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 per manent set, thirty-two in number, though these do not usu ally all make their appearance during childhood. Marked differences between the proclivities of the sexes are notice able 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 genera tive functions are perfected. Youth terminates at tl>e 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, which has been elucidated by the labours of Price, Milne, Farr, and others ; 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 much extended, and surer data are now available for calculations of probabilities of life, of survivorships, and of the payments which ought to be made in benefit clubs. See INSUEANCE and LONGEVITY. 3. Personal Identity. It might be imagined that there is little danger, with the exercise of ordinary care, of mis taking one person for another ; but the remarkable case of the Tichborne claimant, and some other less-known but perhaps equally singular instances, have demonstrated that mistakes as to the identity of individuals are easily made, and are more frequent than is commonly supposed. Where the identity has to be established or disproved after long absence, exposure to foreign climates and great hardships, wounds, &c., the problem is often one of extreme difficulty. 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 person either congenital or acquired. Such are nsevi or mother s marks, scars, and disunited or badly united fractures, known to have existed upon the missing person. An accurate solution of the question is, nevertheless, often a matter of the greatest difficulty. 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 mar riages, or justify divorce. In Great Britain the age at which the sexes are first capable of propagating the species is 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, however, it occurs at the ages of thirteen and of twelve (or even less) respectively in the male and female. By legislative enactment, 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 may arise from organ:: or from functional causes, the former being alone irremediable, and as such taken cognizance of by the law
courts. On this subject it is unnecessary to enlarge here.