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the body cools. Bodies that are thin and emaciated cool more quickly than fat ones, fat being a non-conductor. The bodies of young children lose heat more rapidly than those of adults, and the bodies of old people more rapidly than those of individuals in the prime of life. A body that is exposed to the air will lose its heat more quickly than when it is inclosed, and a body unclothed will lose heat more quickly than if it were clothed. If the room in which a dead body is lying be large and airy, the heat will be given off more rapidly than if the room be a small, close, and confined one. A body immersed in water loses its heat more rapidly than when it is exposed to the air.
It should be mentioned in this connection that in persons dying from yellow fever, smallpox, tetanus, cholera, and from some other acute diseases, there often occurs a rise instead of a fall of temperature. The cause of this increase of temperature, amounting in certain instances to as much as 9° F., is not yet understood.
Rigor Mortis (cadaveric rigidity), or the stiffening of the muscles throughout the body, is a characteristic sign of death. Rigor mortis may set in within three to six hours, or may be delayed until fifteen to twenty hours, after death. It may last only a few moments, or from twenty-four to forty-eight hours, or even weeks. The variations in time of its appearance and duration appear to depend upon the previous condition of the body. The order in which the muscles pass into the condition of rigor mortis is a very definite one. The muscles of the eye first become rigid; then successively the muscles of the neck, chest, upper extremities, and finally the muscles of the lower extremities. It should be mentioned in this connection, however, that considerable difference of opinion has prevailed among
those who have especially studied the phenomena of rigor mortis as to the exact order in which the different parts of the body pass into that condition, as well as the time of its appearance and duration. Rigor mortis disappears in the same order; that is, the muscles of the neck relax first. The muscles of the extremities may still be rigid, even though the remaining muscles are relaxed. After the rigor mortis has entirely passed off the general pliancy of the body is restored, and decomposition at once begins. Rigor mortis is due to the coagulation of myosin, differing in this respect from ordinary muscular contraction.
It is often asserted that in certain instances, as in death from electricity, and in the case of animals hunted to death, rigor mortis does not occur. This statement is erroneous, inasmuch as rigor mortis is the sequence of death from any cause. But, in the instances just mentioned, it is so slight as to escape observation.
Cadaveric spasm (spasmodic rigidity), or the spasm often occurring at the moment of death, in the case of persons who have died from sudden or violent deaths, though resembling rigor mortis, and sooner or later passing into that condition, is not necessarily identical with it. Cadaveric spasm, occurring in cases of suicide, appears to be due to all the vital energy having been concentrated in the one final muscular effort, and not at all to coagulation
1 Nysten: Récherches de Physiologie et de Chimie pathologiques, etc., p. 384; Sommer: De Signis Mortem Humanis Absolutem ante Putredinis Accessum Indicantibus, Havniæ, 1833; Particula Posterior Caput Octavium, p. 185; Larcher: Archives des Générales Médecine, vol. i., 1862, p. 685; Maschka: Handbuch der Gerichtlichen Medecin, Dritter Band, Tübingen, 1882.
2 Brinton: American Journal of Medical Science, January, 1870; Ogston: British and Foreign Medical Review, April, 1857, p. 303.
of the myosin of the muscle. The weapon in such cases is often grasped with such firmness that after death it requires considerable force to remove it.
Suggillation.-In connection with the signs of death, the condition known as cadaveric lividity or suggillation may appropriately be mentioned. It is the result of the settling of blood in the capillaries, and gives rise to violet-colored or livid patches, which, while at first isolated, afterward coalesce. Such discolorations are observed in the most dependent parts of the body, such as the back, under surface of the neck, calves of the legs, etc. When occurring in the lungs and other internal organs, cadaveric lividity is known as hypostatic congestion. Cadaveric lividity is sometimes mistaken for a bruise. The latter condition can, however, readily be distinguished from cadaveric lividity, since, if a bruise be divided by a scalpel, either effused blood or a clot will be found.
Putrefaction, or the decomposition of nitrogenous substances by certain bacteria, with the development of gaseous foul-smelling products, is usually regarded as the most positive sign of death.1 The length of time intervening between death and the beginning of putrefaction varies very considerably according to the conditions of the body as well as those of the surroundings. Thus, fat and flabby bodies, those of new-born children, and of women dying in childbirth, putrefy rapidly, probably on account of the amount of fluid present in the body under such circumstances. The bodies of persons dying from exhaustive diseases, such as typhus fever, or from injuries involving the bruising and mangling of the bodies, or from poisonous gases like carbonic oxide, etc., undergo putrefaction
1 Flügge, Dr. C.: Micro-organisms, translated by W. W. Cheyne, London, 1890, p. 608.
quickly. Putrefaction is retarded, however, in cases of death from alcohol, phosphorus, arsenic, and certain narcotic poisons. While the phenomena of putrefaction are undoubtedly due, as already mentioned, to the presence of certain bacteria, the products of the decomposition of the albuminous substances being subsequently modified by the oxidizing action of the atmosphere, present under ordinary circumstances, nevertheless, the rapidity of the process will be greatly influenced, not only by the amount of moisture present in the atmosphere, but by the temperature of the latter.
Indeed, putrefaction is arrested in the presence of perfectly dry air. Thus, in the sandy deserts of Arabia and Africa, a dead body, losing rapidly its fluids, dries up and mummifies, while bodies buried naked or but very little clothed in wooden coffins, in shallow graves to which the air has ordinarily access, putrefy rapidly. The influence of temperature in promoting or retarding putrefaction is well shown by the fact that bodies putrefy more rapidly in summer than in winter. Indeed, putrefaction is entirely arrested at a temperature of 32° F., as well known; bodies of men and animals buried in ice for nearly a hundred years have been found in a state of perfect preservation after exhumation. The temperature most favorable to putrefaction appears to be between 70° and 100° F., a temperature of 212° arresting it. Putrefaction is undoubtedly due to the presence of bacteria, its progress being modified by the condition of the body at the time of death, the age and sex, the amount of moisture in and the temperature of the atmosphere. Nevertheless, as it has been observed that the decomposition of bodies of the same general character buried in the same kind of coffins and graves varies very considerably, there must be other
conditions than those just referred to, and not so well understood in their effects, that influence the rapidity of putrefaction.
It may be mentioned that bodies putrefy more rapidly in air than in water, and more rapidly in air or water than in earth. Inasmuch as putrefaction is influenced by so many conditions, it is impossible to state exactly when it will first appear or the length of time before a body will entirely be decomposed. As a general rule,' it may be said, in the case of bodies exposed to the open air, that within a period after death of from one to three days in summer, and three to six days in winter, there appears a greenish or greenish-yellow spot upon the abdomen about three inches in diameter, accompanied by the peculiar odor of putrefaction. The eyeball at the same time becomes soft and yielding. During the next succeeding few days-three to five-this greenish discoloration spreads over the body in coalescing spots. Within ten days the epidermis begins to loosen, and at the same time blisters with fluid begin to form. The chest and abdomen become at the same time distended and swollen with the gases which in the mean time develop. The sphincter ani becomes relaxed, and reddish streaks appear along the course of the blood-vessels. By the end of two or three weeks the blisters have broken, maggots have made their appearance, and the nails have loosened. The development of gases continuing, the abdomen becomes very much distended. The penis is now enormously swollen and shapeless, and the scrotum is enlarged, in some cases, to the size of a child's head. The hairs of the head are loose and can readily be pulled out. Within a period of from four to six months the walls of the body-cavities
1 Casper: Handbook of the Practice of Forensic Medicine, 4 vols., Lon
don, 1861, vol. i. pp. 33, 37, 40, 52.