Adipocere (Lat. adeps, fat, and cera, wax, from its fatty origin and waxy consistency), a white, solid, non-putrescible substance, into which human bodies are sometimes converted after burial. If the dead body be left exposed to the air at a moderate temperature, it undergoes the process of putrefaction, and is rapidly decomposed with the evolution of offensive and putrefactive gases. If buried in closed coffins with a limited supply of air, or in a tolerably dry soil, the process is somewhat modified; the putrescent character of the changes is less marked, the offensive effluvia are much less abundantly developed or are absorbed by the soil, and the body slowly decomposes, losing its original form and structure, and finally crumbling away to powder, leaving only the bones, which remain for a long time after the remainder of the body has become unrecognizable. But occasionally it has been found that bodies disinterred after the lapse of many years have not undergone either of these changes, but on the contrary have been con-verted into a white, solid, and very heavy substance, of firm consistency, retaining the original size and contour of the frame, so that the features may still be distinguishable, and even the natural markings and texture of the skin distinctly apparent.

This substance is adipo-cere. It does not putrefy, but has evidently remained unchanged for a long time while buried, and after disinterment continues with but slight alteration. After exposure to the air it simply becomes lighter in weight, drier and more granular, owing to the evaporation of the water which it contained; so that a body which has undergone this conversion may be afterward preserved for an indefinite time without changing- materially in form or appearance. It is this change, or conversion of the soft parts into adipocere, which gives rise to the instances occasionally reported of human bodies being found after some years in a state of so-called petrifaction. The white color, solidity, and weight of the bodies thus found naturally suggest to the popular mind the idea of their having become petrified; but the change which they have undergone is in reality a very different one, and has little or nothing in common with a true petrifaction. - It is found that, for a body to become changed into adipocere, two principal conditions are mainly requisite. First, the body at the time of its burial must be fat. Lean bodies, as a rule, do not undergo the change in question, but only those which arc abundantly supplied with adipose tissue.

And yet it is not the adipose tissue itself which is converted into adipocere; it merely supplies some of the necessary elements, which are employed in effecting the alteration in other tissues. The second necessary condition is that the body should be buried in a moist place, and one in which the water collects in considerable quantity and remains standing at or about the level of the coffin, without being rapidly changed. Thus a single body, buried in marshy ground, or even deposited in a tomb which is undrained and collects standing water, will sometimes be found to have undergone the alteration. A collection of many bodies in or near the same spot seems also to favor the change. The first notable instance in which it was observed was on the removal in 1787 of the bodies deposited in the Cimetiere des Innocents in Paris, where they had been accumulating for eight or nine centuries, many of them being found in the condition of adipocere. In 1849, in the city of New York, an old potter's field burying ground, situated at the junction of Forty-ninth street and Fourth avenue, was demolished and the bodies removed. Many of them had been buried in trenches or pits, in which the coffins were piled one upon the other, sometimes six or seven deep.

This was said to have been done during the cholera epidemic of 1832. On removal of the bodies, those occupying the upper and middle tiers were found to be nearly or altogether decomposed; those forming the one or two lowermost tiers, beneath the level of the water retained by the soil, had apparently been converted into adipocere, but had been subsequently in great part dissolved and disintegrated by the water; while those situated between the two were in many instances also converted into adipocere, but completely preserved, retaining, with but a few changes, their natural form and size. - The process of the conversion of a human body into adipocere under such circumstances appears to be the following: The fatty substance of the adipose tissue first undergoes a change, by which it becomes rancid and produces two fatty acids, the oleic and the margaric acids.

These acids are liquid, and, being in large quantity, penetrate the neighboring tissues, so that the skin, muscles, etc, become permeated and saturated with them. At the same time, the albuminous matter of these tissues, beginning to undergo decomposition, produces a small quantity of ammonia, which unites with the fatty acids, making an ammoniacal soap. The greater part of these acids, however, is taken up by combinations of lime, forming an oleate or margarate of lime, substances comparatively insoluble and non-putrescible. The lime is derived partly from the soil, being brought down in solution by the rain water as it filters through successive layers of superincumbent earth. If other bodies are piled above, the water which filters through also brings the products of their decomposition and partial solution, among which are ammonia and lime, until the whole of the fatty acids of the bodies lying at the requisite level have combined with these bases, and have become in this way converted into adipocere.

Thus the tissues, already permeated by the fatty acids, are now saturated with their ammoniacal and calcareous combinations, and especially with the oleate and margarate of lime, which protects them from further decomposition, and causes even their minute anatomical structure to be indefinitely preserved. These bodies when first taken out are, as we have said, dense and heavy, owing to the abundant moisture which they contain; but this soon evaporates after exposure to the air, leaving them comparatively light and dry. - It is not by any means all the tissues and organs of the body which are converted into adipocere, even under favorable circumstances. The adipose tissue itself disappears more or less completely, since its principal ingredient is used up in accomplishing the alteration of other parts. The internal organs generally, such as the heart, lungs, brain, liver, spleen, kidneys, etc, become shrivelled and disintegrated and finally undistin-guishable. But the skin, fascia, tendons, fibrous membranes generally, and especially the muscles of the head, limbs, and trunk, are all more or less completely preserved.

The muscular texture is easily recognizable by the naked eye, and the natural folds of the skin, or accidental impressions made upon the surface by portions of the dress or ligatures, may be plainly discernible after the lapse of many years. The bones, teeth, hair, and other less destructible parts of the body, do not seem to be particularly influenced by the change, but undergo only the usual very slow and almost imperceptible alterations which they would present in ordinary cases.