No. 1, (the melting point of which was 57.5°, the solidifying point 52°) was melted with an equal weight of alcohol, and on cooling, filtered and pressed; a very dark liquid ran through, a drop of which, evaporated on a glass slide, gave dendritic, stellate, polarizable crystals. To the residue weighing 177 grammes, 100 grammes of alcohol were added, and the fat which separated, together with some depositing from the last filtrate by standing, were added to the fat of the previous operation; the fat which separated from this solution of 177 grammes, melted at 59°-60°, and solidified at 53°-54°. The dark-coloured alcoholic liquid, filtered from these fats, was saponified by an alcoholic solution of potassa; the alcohol expelled by boiling with water, and after transferring to a retort, was boiled with sulphuric acid. The distilled water, examined for volatile fatty acids, gave negative results. The fat was very dark in colour, melted at 55°, and solidified at 50°, though it was difficult to determine these points exactly, as the change exhibited itself very gradually. A portion of this fat was converted into a potassa salt, and precipitated by chloride of barium; the filtrate from which, treated with hydrochloric acid, gave a small quantity of a yellow fat, not further examined.
The baryta salts were treated by ether, and the residue by boiling alcohol. The ethereal, alcoholic solutions, and the residue, were severally decomposed by hydrochloric acid. The ethereal solution gave a small quantity of oleic acid, in very dark drops. The alcoholic solution fat was also small in quantity, and dark. It fused at 61°-62°, and solidified, as well as could be judged, at 45°. The residual fat, which was the largest in quantity, yellow, and of a waxy surface, melted at 43°-46°, and solidified at 45°-40°.
The purification of fat No. 2, was now undertaken, and experimented upon more particularly than No. 1, since this specimen of adipocire conformed to the shape of part of the human frame.
1o. An equal weight of alcohol was added, and the fat, which weighed 644 grammes, was dissolved by heat; on cooling it was pressed, and as the filtrate deposited more fat on standing, it was pressed again, and the fat added to the former. The dark-coloured filtrate was bottled, and the fat melted. It was of smooth and waxy surface, and weighed 511 grammes.
2o. The fat from 1o was melted with 170 alcohol, and the same operation performed. Residue weighed 327 grammes.
3o. Added 124 alcohol to this fat. In this all the liquor was absorbed by the pressing cloths; the fat weighed 335 grammes.
4o. Added an equal weight of alcohol and melted; pressed after two days. The liquid by this time, was light yellowish; the fatty crystals in white flakes or scales; the smaller ones transparent under the microscope, and polarizable. A portion of the fat was melted, and observed cooling under the microscope with polarized light; as the solidification approached, a beautiful play of prismatic colours took place, and the drop shot into crystal interlaced lamellæ. A drop melted with alcohol, and let cool, gave the peculiar dendritic curved appearance of margaric acid.
5o. The fat by this time weighed 300 grammes; it was melted with an equal weight of alcohol, and pressed the following day. Residue, 253 grammes.
6o. This was melted with 250 alcohol; the liquid from the press was very little less coloured than the last; the residue weighed 227 grammes, and was brilliant white, with a tinge of yellow; the fracture showed large crystals, and could not be distinguished from the product of the stearic candle factories. When melted, it cooled with raised, uneven surface, and was completely soluble in ether. When the ethereal solution was suffered to separate spontaneously, the first fat which made its appearance melted at 60°, solidified at 55°, and the fat extracted from the rest of the ether gave exactly the same points.
The following are the melting points yielded by the fatty residues of the foregoing alcoholic crystallizations: