In drowned cases where all the skin is slipping it is best to envelope the whole body with a layer of cotton saturated with formaldehyde. =Rigor Mortis.=—Rigor mortis is the stiffening condition which occurs on the body after death. When the muscle substance dies it becomes rigid, or goes into a condition of rigor; it passes from a fluid to a solid state. The rigor that appears in the muscles after somatic death is designated usually as rigor mortis, since its occurrence explains the death stiffening in the cadaver. It is characterized by several features: the muscles become rigid, they shorten, they develope an acid reaction, and they lose their irritability to stimuli. After the death of an individual the muscles enter into rigor mortis at different times. Usually there is a certain sequence, the order given being the jaws, neck, trunk, upper limbs, lower limbs, the rigor, therefore, taking a downward course. The actual time of the appearance of the rigidity varies greatly, however; it may come on within a few minutes or a number of hours may elapse before it can be detected. Death after great muscular exertion, as in the case of hunted animals, or soldiers killed in battle, is usually followed quickly by muscle rigor. Death after wasting diseases is also followed by an early rigor, which in this case is of a more feeble character and shorter duration. Certain drugs such as veratrum, hydrocyanic acid, caffeine and chloroform, will hasten the development of rigor. People who die in full habit, meaning that there has been no muscular exertion or wasting processes before death, usually have the rigor developing more slowly and of a longer duration. After a certain interval, which also varies greatly, from one to six days, the rigidity passes off, the muscles become soft and flexible; this phenomenon is known as the release of the rigor. The usual explanation that is given of rigor is that it is due to a coagulation of the fluid substance, the muscle plasma, of which the fibers are constituted. During life the fluids exist in a liquid or viscous condition; after death they coagulate into a solid form. Rigor mortis is not a sign of death, as there is rigidity of the muscles following apparent death, as in cases of asphyxia and trance. If the body is rigid, in a case in which there is a doubt that death is present the rigidity may be broken up. If it is a case of trance or that of the contraction of the muscles following drowning, it is likely to return, especially in case of trance; but if death is actually present it will not return. The chemical changes occurring, the result of rigor mortis can be briefly stated: (a) There is a coagulation of the proteid material of the muscle plasma. (b) There is an increased acidity, which is doubtless due to the production of lactic acid. (c) There is a production of carbon dioxide. (d) There is a consumption of glycogen.