Part 4

(a) and (b) were united, dissolved in alcohol, enough alcoholic solution of acetate of magnesia to precipitate the half added, and after standing for a couple of days, the precipitate was filtered off, and ammonia added to alkaline reaction to the filtrate. The first magnesia salt was translucent, and fused by heat to a transparent liquid, which by more heat gradually grew darker, finally black, and left a residue of magnesia. The melting point of the fat of this substance was as before, 61°.

The second magnesia salt was white and amorphous; it presented the same relations to heat as the first, and contained a fat of the same melting point, 61°. These fats were both brilliant white, lamellar, and of rough surface. The first magnesia salt contained a per centage of 7·59 MgO (0·25025 gave 0·019) and the second contained about double the per centage of magnesia, viz.: 14·91; for 0·28 salt gave 0·04175 magnesia by incineration.

Neutral palmitate of magnesia C{32}, H{31}, O{3} MgO gives by calculation 7·6 per cent. magnesia, and basic palmitate C{32}, H{31}, O{3} 2 MgO gives 14·15 magnesia, which approaches the nearest to the magnesia salt of the above fatty acids.

The experiments of fractional precipitation of the normal solution of fat 6°, were conducted in the same manner, and with the following results, in which (c) and (d) represent the fatty acids of the two magnesia salts, and (e) that of the portion not precipitated by an excess of acetate of magnesia:

(c) 0·474 melt pt. 59.5° (d) 0·440 melt pt. 61.5° (e) 0·356 melt pt. 58.5° loss during the ex. 0·010 ————— 1·280 grammes of fat.

The magnesia salts from which the fats (c) and (d) were separated, gave as follows:—(c) 0·227 gave 0·01675 = 7·38 per cent. magnesia; and (d) 0·1735 gave 0·012 = 6·92 magnesia. On comparing the melting points of these fats, and making allowance for want of a more perfect separation from impurities, there can be little doubt that they are neutral palmitates of magnesia, as was before ascertained. According to Heintz (Zoochemie, p. 1072,) stearic acid is C{36}, H{36}, O_{4}, and the magnesia salt contains by calculation, 6·9 per cent. of that base. The foregoing experiments upon the two specimens of human adipocire were intended preliminary to a more thorough research into their nature, by Heintz’s method; but this process requires such a large quantity of substance in order to effect the separation of small quantities of whatever new acid might be present, and the amount of material dwindled so in the many necessary crystallizations from alcohol to separate the dark-coloured impurities, and especially, since the determinations and reactions already made, were so confirmatory of what has lately been done in working upon the solid fatty acids, I preferred placing aside the substances thus obtained for a future examination, when the separation of fatty acids shall have become more simplified, as it must be before long.

(c) Fossil adipocire of Bison Americanus obtained from a metacarpal bone from Big Bone Lick, by Dr. Leidy.--It was a white powder, and in pulverizable lumps; amorphous under the microscope; with a talcose feel, and of density a little below 0·8365, since it barely swims upon alcohol of that strength, while it sinks in absolute alcohol. Water will not wet it; with the addition of hydrochloric acid and heat, it is separated without effervescence, into a mineral solution, and into an oil which solidifies on cooling to a nearly white fat, a small portion of which melted on a glass slide solidifies to a confusedly crystalline mass; a small quantity treated in the same way with absolute alcohol, crystallizes in plumose and dendritic crystals, like margaric acid. A portion of the adipocire boiled with absolute alcohol, yields but a minute quantity to the solvent, and that not of a fatty nature, showing that the fatty acid is wholly saponified with an earthy base. The whole quantity of adipocire weighed 0·986 grammes. 0·16325 heated in a platinum crucible, fuses, burning with a smoky flame and with the smell of fatty acid, but no acroleine, leaving 0·0165 or 10·1 per cent. of a perfectly white ash, which hydrochloric acid almost perfectly dissolves without effervescence, and which consists almost entirely of lime, with a few minute specks of oxide of iron (seen during the action of the hydrochloric acid,) and a couple of small grains of sand: there is a very small trace of phosphoric acid present. The greater portion of the adipocire, 0·716 grammes, was decomposed by hydrochloric acid and water, by the aid of heat: the decomposition took place with a strong smell of rancid tallow, and the fundamental smell observed in all adipocire was emitted. It was melted and washed several times, at first with acidulated and finally with pure water. The water from the washing, when evaporated, gave a certain quantity of brownish yellow colouring matter. The fat was melted in the capsule in which the precipitation took place, and weighed 0·618 or 86·31 per cent. of the adipocire; when melted, a dark flocculent humus-like precipitate was seen; the fat itself was yellowish, and of a flat, waxy (here and there warty) surface. It melted at 51°.

The adipocire therefore appears to be a lime soap of one of the fatty acids, with a trace of phosphate of lime and with flocculent organic matter, or in per centage approximately,

Fatty acids and a little colouring matter, 86·31 Lime and a trace of phosphate, 10·10 Flocculent organic matter, 3·59 —————— 100.00

If the organic matter be neglected and the per centage then calculated, we will have,

Fatty acids, 89·5 Lime, 10·5 ————— 100·0

Now Stearate, Margarate and Palmitate of Lime, respectively contain a per centage of 9·3-9·7——10·2, of lime, so it is reasonable to suppose (as there is nothing in its reaction contrary, but everything favourable to this supposition) that the fossil adipocire is a neutral lime soap of the usual fatty acids of tallow.

Experiments upon the decomposition of muscular fibre (bullock’s heart) with water, with a view to the formation of adipocire.

A portion of raw, and one of boiled muscular fibre from bullock’s heart, were on March 8th, 1854, placed with water upon a microscope slide, and covered with thin glass, which was closed with sealing wax around the edge to prevent evaporation. This was repeatedly observed during the year, and the attention was directed at times to particular fibres the better to watch any change. At the commencement of the experiment, the cross-markings of the fibre were distinct and the fibre itself was of a delicate rose-colour. I find in my notes of April 8th, and May 11th, that no change presented itself in either the raw or in the boiled fibre, except that the cross-markings were more distinct. On December 6th, 1854, but very little change was noticed, (the raw fibre was whiter,) the cross-markings in both were more distinct than ever; by high powers an amorphous precipitate was discovered in the neighbourhood of some of the fibres--about one third of the water had evaporated.

A. On November 14th, 1853, 100 grammes of cheese were placed in a loosely stoppered bottle, and covered with distilled water, a portion of the same cheese being reserved for comparison: the water was renewed as it evaporated.

Ba. On November 19th, 1853, one half of a bullock’s heart, weighing 673 grammes, was placed, covered with Schuylkill water, in a wide-mouthed stoppered bottle.

Bb. The remaining half of the heart, weighing 816 grammes, was covered with mineral water with lemon syrup. It was intended to use plain mineral water in this experiment, that is, Schuylkill water saturated with carbonic acid, but the former was sent by a mistake, which was not discovered until too late. In these cases the fat was partially removed from the heart, but not to any great extent.

C. Boiled six eggs, removed the shells from two, which weighed then 88 grammes; ran pin-holes to the centre in two, which weighed 97 grammes, and left the shells upon the remaining two, which weighed 96 grammes; these were together placed in a glass-stoppered bottle, and covered with water. These different substances did not delay to decompose and give out offensive odours, and the eggs especially maintained their proverbial character in this respect; in fact, on the approach of the cholera season I was obliged to place the bottle of eggs on a plate, cover it with a large inverted beaker glass, and heap the rim of the beaker with hypochlorite of lime. With regard to the heart, the contents of the bottle containing mineral water, as might be expected, preserved their lively red colour for a longer time than in the case of the bottles containing river water.

The appearance of these bottles, on December 13th, 1854, was as follows:—

The cheese A was converted into a white, thick, grumous mass, lighter than water, and which when diluted with a little water, presented the appearance of pus; under the microscope with moderate power, angular transparent fragments constituted the principal part, and among these, polarized light showed many broken blade-shaped crystals without a play of colours; a few globules of oil were also seen. The material A was removed to a glass-stoppered bottle, more water added, and was set aside. A portion of the cheese used in this experiment had been preserved in paper; it was found hard, and on the surface oily. It was placed aside in a cork-stoppered bottle.

B. The bullock’s heart had been so divided, that each half contained an auricle and ventricle, which were placed in the bottles, (a) with water, (b) with carbonic acid water. The appearance of the contents of these bottles at present is similar, though (a) seems to be more disintegrated. In both of these, the cavities and valves of the heart maintain, in a measure, their form, and the chordæ tendineæ are in perfect preservation: the serous covering of the heart is consistent; and in (b) it is, in parts, quite black from sulphuret of iron. The fluid in both bottles reacts strongly alkaline; when the mass of the heart is cut open, the muscular fibre appears of a dirty, yellowish-red colour, and when examined under the microscope, shows the fibre, but without any of the cross-markings in (b). In (a), which was more disintegrated, by the addition of water and a power of 700 diameters, the fibre could be seen broken in small portions, and giving evident traces of both longitudinal and cross-breaking up of the sarcous substance. The fibres of (a), treated with hot and cold alcohol evinced no change; with hot acetic acid they shrunk in dimensions. The weight of (a) dripping with liquid was 330 grammes, that of (b) 275 grammes.

C. The Eggs.--The water was strongly alkaline; the shelled eggs were seen in broken, yellowish-white lumps, and a thick deposit at the bottom of the bottle, gave no evidence of crystallization under the microscope with polarized light. The liquid from the eggs and from the two heart experiments emitted rather a disagreeable odour, which was mingled with an aldehyde smell.

As decomposition had not advanced to its full extent in these bottles, I preferred setting them aside for a future research, when both the solid and the liquid contents will be examined. Braconnot’s analysis of bullock’s heart is as follows:—

Water, 77·03 Fibrine, cellular tissue, nerves, vessels, 17·18 Albumen and colouring matter of the blood, 2·70 Alcoholic extract and salts, 1·94 Aqueous extract and salts, 1·15 —————— 100·00

ARTIFICIAL FORMATION OF ADIPOCIRE.

On December 8th, 1853, a bullock’s heart weighing 1240 grammes, without removing its fat, was buried in sand in an inverted tubulated receiver held in a retort stand, and so placed against the glass that a portion of it could be seen: a reservoir of water was placed above the receiver, and this water was suffered to fall, drop by drop, upon the sand by means of a syphon of lamp-wick. The water was removed when necessary, and the changes appearing in the heart observed. These changes were the same as in the case of the bottled experiments; it began soon to deepen in colour, and on May 11th, 1854, was quite dark, while the liquid falling from the receiver contained a black amorphous precipitate, which is probably, from Liebig’s observation of a similar case, sulphuret of iron. A deep zone of green vegetable parasitic matter was visible around the inside of the receiver, commencing within half of an inch above the position of the heart where it was deepest in colour, and thence diminishing as it approached the surface of the sand. On June 7th, the heart was removed and dissected for the purpose of viewing the extent of the decomposition: it maintained its original form, but was larger; the separation of the chambers was apparent; the valves present and the chordæ tendineæ in a perfect state; the greater part of the fleshy walls of the heart was pinkish, soft, of the consistence of lard, of putrid smell, and under the microscope (700 D,) presented an amorphous mass, mingled with fragments of crossed muscular fibre. It was not in as advanced a stage of decomposition as the bottled hearts of December 13th, 1854. The fat which was purposely left around the coronary vessels, was hard, white, and of an appearance approaching that of adipocire. The heart was returned to the vessel and the experiment continued. On my return to the city, after an absence in the summer time, I found that the water reservoir and lamp wick had fulfilled their duty, for the sand was still moist. On December 9th, 1854, the experiment was concluded, and the heart removed from the sand and washed. It was in two pieces, and weighed, when still wet, 219 grammes: after drying in the air for five days it weighed 107 grammes, or 8·6 per cent. of the original weight, and was still moist. This was principally the fat from around the coronary vessels, the impressions of which were on it; the tendinous chords of the valves were perfect, and the valves themselves were indicated. The smell was decidedly tallowish, with the strong smell I have described as adipocire smell, and with the smell of earth worms; all of these odours were plain, and suggested themselves at once to the mind. The fat was hard, and resembled exactly adipocire; it presented a different appearance in two different places: one portion was hard and compact, in some parts denser, in others lighter than water, and appeared granular under the microscope, like the specimens of adipocire already described: the other portion was of a more buttery nature, and of about the density 0·8365. Neither of these specimens gave any traces of fat globules with the microscope, but contained aggregations of white angular fatty matter, of nearly the same size, and about one fourth the diameter of fat globules. With ether the fat disappeared, and left shrunken membranous matter, which after the evaporation of the ether and treatment with acetic acid, became, for the most part, transparent. A comparative experiment with beef fat gave similar results, and I am inclined to think that the most of this matter proceeds from the fat cells, and their accompanying cellular tissue.

On cutting through the thickest portion of this adipocire, the fat was of a pure white colour, and could not be distinguished from adipocire; in some portions it was nearly an inch in thickness, and at first sight certainly gave the impression that the fleshy walls of the heart were converted into fat; but on closer inspection, this seemed to me improbable. The lumps of adipocire were thickest at the top of the heart, and just where were the lumps of fat in which the coronary vessels were imbedded; moreover, it was the most like adipocire in the centre of those very portions of fat. I obtained the approximate density of the adipocire of this part, by diluting alcohol with water, until the adipocire just swam half way between the surface and the bottom of the liquid, and found it to be 0·8902, which is by experiment lower than that of ox fat. Indeed, as would a priori seem probable, the fat, by the gases evolved during the putrefaction of the proteine bodies, is rendered more porous, and of a lower specific gravity, which deceives the eye, and makes the mass of fat to appear greater than it really is. An ash determination of this part of the adipocire performed upon 1·471 grammes, yielded 0·0015, equal to 0·102 per cent. of a reddish ash, containing iron. No acroleine was observed during this experiment, and no other than the characteristic adipocire smell, which proves the absence of glycerine, and that the fatty acids are uncombined. Ox fat (2·069) gave (0·001, or) a per centage of 0·048 white ash. The iron of the former proceeds probably from the hæmatine in the heart. These ashes are too small in quantity, to arrive at any satisfactory result in ascertaining the nature of their component parts; they appeared by a few tests to contain principally lime, and soda and potash were detected by Smith’s test. The melting point of the above portion of adipocire was about 47°, but at 52° the fat still contained a faint precipitate.

The adipocire, on February 3d, 1855, until which time it had been kept in a loosely stoppered bottle, weighed 97 grammes, which is 7·8 per cent. of the original heart. From 91 grammes the fat was separated by boiling it with 317 alcohol, filtering hot, pressing powerfully, and weighing the residue; the latter was bulky, and weighed 40·1, corresponding to 44 per cent. of the adipocire, which contains, consequently, only 66 per cent. of fat. If the per centage of fat be calculated from the original weight of the heart, it amounts to only 4·4, which is undoubtedly less than was originally in the heart, so that, so far from there being a gain of fat in the formation of the adipocire, there was actually a loss, which accords with the bottle experiments. The alcoholic solution deposited 16·2 grammes of a rather dark fat, which was recrystallized from 368 grammes of alcohol, and yielded 11 grammes of a lighter fat. I was desirous of retaining a greater portion of this fat for future experiments, and without proceeding to purify it further, obtained its equivalent. It melted between 69°-70°, did not crystallize plainly from alcohol, with which it behaved like stearic acid: a neutral silver salt, deepened in colour considerably when dried at 100°, and gave only 20·59 and 20·68 per cent. of silver. As decomposition had evidently taken place in this salt, the baryta compound was prepared by adding acetate of baryta to the alcoholic solution. The baryta was determined both as carbonate and by converting into sulphate; there was no difference in the two results; the baryta of the carbonate was 0·1701, and that of the sulphate was 0·1700, which corresponds to a per centage of 19·65--stearic acid (Heintz) requires 21·76 per cent., and palmitic acid 23·62 per cent. of baryta for the neutral salts. I have no doubt that a further purification will show this to be stearic acid, as might be expected from the original fat of the heart.