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 tothe 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,[9]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 otherthan 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 theadipocire, which contains, consequently, only 66 per cent. of fat. If the per centage of fat be calculated from the original weight of theheart, 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.
I am not desirous of claiming for these experiments a greater importance than they deserve, nor any but that the experiments were carefully performed: they were extended over the greater part of a year, during which my attention has been particularly directed to this subject. When the investigation was commenced, I was inclined to the belief that adipocire was a result of the decomposition of the blood-forming substances, and this, principally, from the experiments of Blondeau (see first part of this article) which I have not seen refuted, and partly from the testimony of those who have had opportunities of observing the formation of adipocire, and who have stated that fleshy parts of the bodyare wholly converted into it. The formation of the lower terms of the series of fatty acids from proteine bodies forbids maintaining that this is impossible; but from what I have seen, and on weighing the evidence of what I have read, my impression is, that adipocire proceeds from the original fat of the body.
It appears to follow from the foregoing experiments, that the higher members of the series of fatty acids do not result from the putrefaction of proteine compounds; at least from such putrefaction as is accompanied by exclusion of air. Flesh fibrine with restriction of air does not putrefy as rapidly as would be supposed, according to the experiment, where a portion was sealed with water on a microscope slide; the air here was not absolutely excluded, since a partial evaporation of the water took place. It is true that the amount of water in this experiment was small, in proportion to the fibrine, and it appears that much water is necessary to such decomposition, and which supports Liebig’s theory of the motion of the molecules. In the experiments of the bottles and of the sand, the decomposition wasseen to take placegradually; the sarcous element of the flesh fibrine separated into discs, and these were by degrees resolved into their simpler compounds, which either remained as liquids or gases in solution in the bottles, or were carried off by the droppings in the sand experiment. The original fat of the body, according to circumstances, either partakes of this decomposition, or else, losing its glycerine and most of its oleic acid, becomes gradually converted into adipocire. In some bodies in the grave yards the fat is totally gone, while in others large quantities of adipocire are formed. It is suggestive that in all cases where adipocire has been found, the corpse was of a large and fat person, and this abundance of fat resists an ultimate decomposition. Analyses by Beetz of candles which had remained for a hundred years in a mine, prove that the only alteration undergone by fats when alone, is destruction of their oleine and glycerine. In the bottles of my experiments no adipocire was formed, although the fat of the coronary vessels was only partially removed; this may be accounted for on the ground that the fat, which was small in quantity, was here kept in close contact with the decomposing fibrine, and suffered with it decomposition, whereas in the sand experiment, this could only take place to a less degree. In grave yards, if the proportion of flesh to fat be large, and especially if the ground be of such a nature as to prevent the decomposed matter being carried off, as by draining, adipocire cannot be formed, but the fat undergoes full decomposition.
The fact that in adipocire from different animals, the same substances are found accompanying the original fat of the animal, as the goat-like or mutton smell in sheep, and the tallow smell of the fossil adipocire, is suggestive, and should shift the burden of experimental proof upon those who maintain the formation of this substance from fibrine. The microscopic experiments militate against the transformation from fibrine. Those that believe in this change think to have proof from the shape, as it were, of certain musclestransformed into fat; but fibrine does not require to lose much substance in the shape of ammonia, &c., for this transformation, and there would not be, therefore, a great disturbance in the shape of the fibres of muscle; at any rate, it would be reasonable to expect, that with the microscope, traces of an arrangement of the fatty particles into fibres or rows would here and there be seen, but this is not the case, and the appearance is that of fat particles of equal size among themselves, and of a diameter one-fourth that of the original fat globules, and indeed presenting all the appearances to be expected from a mass of fat undergoing alteration from the decomposition of its oleine and glycerine; and finally in the experiment where adipocire was artificially formed, no gain of fat was observed, but a loss of what was purposely left upon the specimen under examination.
I shall delay an examination of the products in my hands, until the separation of the fatty acids is improved. It would be easy enough with the present methods to isolate the two principal constituents of the fatty acids from the material in hand; but small quantities of new products would inevitably escape observation.
Thedesideratain working the fatty acids at present, are, First, separation of the oleic acid, without too much loss of substance.
Second, a less circuitous method of separating the fatty acids than by Heintz’s method, which renders difficult the isolation of small quantities of a different acid, as shown by his mistake of anthropic acid.
It is probable that a crystallization of salts (especially with a base of a high equivalent) would effect this purpose, for in crystallization, other compounds and impurities are concentrated in the mother liquids, while in fractional precipitation, in the present case, an infinite subdivision seems to take place, requiring many steps to accomplish a sufficient purification; and brilliant as Heintz’s results are, considerable labour was required to arrive at them. Heintz’s process of partial precipitation was founded upon the method of fractional distillation, proposed by Liebig for the separation of the lower members of the series of fatty acids; in the latter case presence of an alkaline carbonate, in quantity insufficient to saturate the mixed acids, alters their volatility, while in the former, presence of a salt in insufficient quantity for perfect decomposition changes the relations ofsolubilityof the salt formed, and it does not necessarily follow that the chemical affinity, active in both cases, will afford asexpeditiousa method in cases of solubility as in those of volatility.
FOOTNOTES:[1]Liebig thinks this probable. Ch. Briefe.[2]The degrees of thermometer in this article are centigrade, and the weights grammes.[3]Lehmann, Lehrbuch.[4]Lehrbuch, III. p. 187.[5]Lehmann.[6]The liquid from No. 3 was all absorbed by the pressing cloths, and not collected.[7]Since the above was written, I have received the Journal für Pract. Chemic., Heft III. Band LXIII. in which some late results by Heintz on this point are communicated. He artificially prepared chemically pure stearine from the acid and glycerine, by Berthelot’s process, and found that it had two melting points, first at 55°, then solidifying and melting again when the heat reached 71.6°.[8]Ann. de Ch. & de Ph., xvii. p. 390.[9]See Kolliker, Mic. Anat., II. 1st Part, page 16.
[1]Liebig thinks this probable. Ch. Briefe.
[1]Liebig thinks this probable. Ch. Briefe.
[2]The degrees of thermometer in this article are centigrade, and the weights grammes.
[2]The degrees of thermometer in this article are centigrade, and the weights grammes.
[3]Lehmann, Lehrbuch.
[3]Lehmann, Lehrbuch.
[4]Lehrbuch, III. p. 187.
[4]Lehrbuch, III. p. 187.
[5]Lehmann.
[5]Lehmann.
[6]The liquid from No. 3 was all absorbed by the pressing cloths, and not collected.
[6]The liquid from No. 3 was all absorbed by the pressing cloths, and not collected.
[7]Since the above was written, I have received the Journal für Pract. Chemic., Heft III. Band LXIII. in which some late results by Heintz on this point are communicated. He artificially prepared chemically pure stearine from the acid and glycerine, by Berthelot’s process, and found that it had two melting points, first at 55°, then solidifying and melting again when the heat reached 71.6°.
[7]Since the above was written, I have received the Journal für Pract. Chemic., Heft III. Band LXIII. in which some late results by Heintz on this point are communicated. He artificially prepared chemically pure stearine from the acid and glycerine, by Berthelot’s process, and found that it had two melting points, first at 55°, then solidifying and melting again when the heat reached 71.6°.
[8]Ann. de Ch. & de Ph., xvii. p. 390.
[8]Ann. de Ch. & de Ph., xvii. p. 390.
[9]See Kolliker, Mic. Anat., II. 1st Part, page 16.
[9]See Kolliker, Mic. Anat., II. 1st Part, page 16.