The rapidity of decomposition in water varies, being most rapid when the temperature is from 64° to 68° F. Stagnant as well as shallow water favors putrefaction. If a body becomes coated with mud the change is delayed. Submersion in a cesspool also retards it, and the conditions are such as to favor the formation of adipocere.
After a body has been removed from the water an exposure of a very few hours to the air causes rapid decomposition, so that in twenty-four hours more marked changes may occur than would have resulted from a fortnight’s longer submersion. The face soon becomes bloated and black, so that identification is well-nigh impossible. It is quite important in medico-legal cases to estimate the time which has elapsed since death in bodies found submersed in water. The following are the various changes ordinarily seen at different periods of time, as estimated by Devergie, who has especially investigated the subject:
First Four or Five Days.—Little change: rigor mortis may persist, particularly if the water is cold.
Fourth or Fifth Day.—Skin of the ball of the thumb and little finger, also the lateral surface of the fingers, begins to whiten. This whitening gradually extends to the palms of the hands and soles of the feet. The skin of the face will appear softened and of a more faded white than the rest of the body.
Fifteenth Day.—Face slightly swollen and red; a greenish spot begins to form on the neck and skin of the mid-sternum. The skin of the hands and feet is quite white and wrinkled. The subcutaneous cellular tissue of the thorax is reddish and the upper part of the cortical substance of the brain of a greenish tint.
At One Month.—The face is reddish-brown, the eyelids and lips green and swollen, and the neck slightly green. A greenish discoloration is also seen over the upper and middle part of the sternum. The skin is wrinkled. The hair and nails still remain intact. The scrotum and penis are distended by gas. The lungs become very emphysematous and overlap the heart.
Saponification.
When the bodies were removed from the Cimetière des Innocents in Paris, in 1786, Fourcray observed that many of them had been converted into a substance which he termed ADIPOCERE. He gave it this name because it resembles both fat (adeps) and wax (cera). Under certain circumstances which will be considered later, it is known to be a late product of the putrefactive processes. Adipocere is a substance of a cheese-like consistency, yellow or yellowish-brown in color, and composed chiefly of a mixture of the fatty acids. Chevreul has shown by analysis that it is a true ammoniacal soap, but that when formed in water impregnated with lime a calcareous may be substituted for an ammoniacal base. This may take place either in a body exposed to river-water or buried in a grave wet by water containing calcium carbonate or sulphate. Saponification can only take place when animal fat is in contact with nitrogenous matter. Neither fat nor fibrin when kept separate will saponify. Skin deprived of all its fat will not be transformed into adipocere.
Saponification commences in the fat of the female breast, of the cheeks and other parts of the body where large accumulations of fat are found, such as around the kidneys and in the omentum. As fat is distributed extensively throughout the body, nearly all parts may undergo this transformation. Taylor gives the following conditions as favorable to the change:
1. Bodies of young persons, because the fat is abundant and chiefly external.