On adipocire, and its formation

by Charles Mayer Wetherill

The following melting points were obtained:—The first crop of crystals from the alcoholic solution of the fat after saponification, which, when melted, cooled with a stellated surface, tried three times by dipping the thermometer bulb in the melted solution, and noting the temperature when it became opaque, gave 55° for the solidifying point. In a capillary tube, begins to melt at 57°, fluid at 59°, on cooling, opaque at 55°; this portion was taken from the capsule on melting the fat, before the whole mass was melted: another portion taken when all was fluid, and after stirring, gave the same results.

The crystalline appearance of the second crop of crystals from the alcoholic solution after saponification, when melted and suffered to cool in a capsule, is similar to that of the first crop; in the capillary tube, begins to melt at 53°, fluid at 54°—55°, on cooling, crystals form in the tube at 51°, and is opaque at 50°. The melting point of the third crop of crystals was 50.5°. In ascertaining the melting points of the different fats described in this paper, I tried the various modes in use, and settled at first upon the following:—A beaker of distilled water (which must be boiled just before using, to prevent air globules settling upon the capillary tubes, which would falsify the result) is placed upon wire gauze upon a retort stand in front of a window, the thermometer hangs, by a string, in this water from another stand, and the lamp must be moveable from under the beaker glass. A piece of string is tied so loosely around the top of the (cylindrical) mercury reservoir of the thermometer, that the different capillary tubes may be readily slipped in and out on raising the thermometer from the water; the heat from the lamp must be such that the temperature of the water rises gradually; the capillary tubes are so placed that they lie closely to the mercury of the thermometer, and when the temperature approaches the melting point, the water is stirred with the thermometer to equalize the heat, the lamp is then removed, and the point of solidification observed in the usual way. I doubt very much the use of noting the point of solidification, as it is influenced so much by extraneous circumstances. The cooling of water and certain salts below their solidifying points, is well known, and the same must take place in these instances. Heintz has noticed how the thermometer rose ten degrees in determining the solidifying point of melted human fat. In one of my experiments, the fat in the tube was separated by minute air globules into three or four columns, quite close together; in observing the fusing point, they all melted at the same instant; but in solidifying, one would be quite clear while those on either side had become opaque, no matter how much the tube was stirred or vibrated by striking the beaker glass. After having observed this in several instances, I abandoned taking the points of solidification, and modified the process for the fusing point, by keeping the water as near that point as possible, and repeatedly lifting the thermometer and attached capillary tube out of the water for a few seconds, that the fat might solidify, and noting the fusing point as that at which it at once becomes liquid; this point is reached twice; first, when the water is being heated, and secondly, as it is cooling: I have found by repetition of the same experiment, that the degree thus obtained, is constant from the first, and I think gives the most accurate results. The mode of using capillary tubes for the fusing points, is convenient, as, at the close of the experiment, they can be sealed at the open end, and placed on a card with descriptions, for future reference. I weighed the quantity of fat in one instance, and found that half a milligramme was much more than enough to obtain the melting point with the capillary tube.

(b) HUMAN ADIPOCIRE.

Towards the close of the year 1853, I visited a grave yard in Philadelphia, the remains of which were being removed, and from which, through the kindness of the superintendent, I obtained specimens of adipocire and valuable information. The surface of the burial ground was depressed about four or six feet below that of the neighbouring streets, and was of a very moist nature. Many of the bodies were converted more or less into adipocire, and of these, all had been large persons. There was none among the remains of children. I obtained specimens from two persons.

No. 1, was from a large man, which had been buried from ten to fifteen years; the ground was very moist, and the coffin rotten; the grave was seven feet deep. The adipocire was from the middle of the coffin, and was in irregular lumps.

No. 2, was from a very large man; buried five or six years; the ground moist, though not so much so as number one; the grave five feet deep. The ground around the coffin was of a bloody colour, and all of the body was decayed, except the lower portion. The shape of the rump was plain, and the legs separate; the fat was at the bottom of the coffin, and the bones (femur, tibia) were lying along it. The adipocire contained an impression of the bone, was spongy and dark-coloured on the inside; and on the outside it was smooth, white, and presented impressions of the grave clothes, and here and there appearances as if of the hair follicles and sebaceous glands, but which lost this appearance when viewed with the microscope. There was no hair on this specimen. The pieces of adipocire of this specimen were large, at the thickest part being about three inches in thickness; they presented the shape of different parts of the leg, though flattened; tough fibrous bands, like aponeuroses, were seen in some parts traversing the mass of fatty matter.

The appearance of these two specimens with the microscope, was very similar to each other and to the sheep adipocire. Powder scraped from them, with a fine needle, gave no appearance of fat globules, but irregular masses, mingled with membranous matter; a portion sliced off with a sharp knife, presented by reflected light, brilliant, white, irregular fatty fragments, but no traces of globules. When alcohol was added with heat, the fat disappeared, leaving membranous matter, and fibres not-anastomosing (the white element of cellular tissue.) The addition of acetic acid causes the fibres to disappear, and without showing nuclei.

Portions of number one presented an appearance as if of the hair follicles, and there were mingled with it cylindrical hairs, of an inch and a half in length, brownish in colour, and quite fine. From these hairs, and from its position in the coffin, adipocire number one probably came from the abdomen. The fat from this portion gave the same appearance under the microscope, as specimen number two. The alcoholic solution of the fat evaporated on the microscope slide, gave the appearance of stellated dendritic crystals, with curved branches, resembling the so called margaric acid under the same circumstances.

The whole mass of fat in the two specimens, seems to be entangled in a web of disintegrated membrane, and fibrous tissue. I have never been able to detect any traces of muscular fibre under the microscope; and Dr. Leidy, who was kind enough to examine specimens with the microscope, communicated to me the same results. The smell of the two specimens was peculiar; what might be called an adipocire smell; for I have observed it in all specimens of adipocire that I have examined. This smell is indescribable, the nearest approach to it being that of fæces, but it is much more disagreeable.

The following melting points were observed from the original adipocire, melted per se in watch glasses, and the fat taken up in capillary tubes. In these specimens, (a) was taken from parts with little, and (b) from parts with much cellular tissue: