THE ANALYST. 15 NOTES ON RAPE OIL, BEEF FAT, AND MUTTON DRIPPING. BY U. T. KINGZETT, F.I.C., P.G.S. Read before the Society of Pzcblic Analysts, December l?th, 1884. SONE years ago 1 commenced an investigation of a number of fats and oils, with the view of obtaining more precise knowledge of their various conatituents and the propor- tions in which they are respectively present. It was only, however, in the case of cocoa butter that I was able to bring my observations to completeness, and these have been already published." The following notes are of a very imperfect character, but as I see no chance of rofsuming the investigation, I record them for what they are worth. THE specific gravity of a carefully selected aample was determined and found to be 0915. 50 grms. of the oil was saponified by long boiling with caustic soda solution.The soap was entirely dissolved in hot water and precipitated by chloride of barium : the precipitate being washed and dried at looQ C. It fused, when dry, and weighed 61.5 grms. Assuming the compound to have been one of brassate of barium with the composition Ba(CzaH4102>2, its weight would correspond to 51.2 grms. of brassic acid RAPE OIL. ' Jour. C'laeHz. ~ O A , 1878, p. 38.16 THE ANALY8T. C22H4202, as against 50 grms. oil employed. This barium compound was soluble in ether, benzene and carbon disulphide. It was dissolved in ether, and precipitated therefrom by alcohol. In this state the reprecipitated compound was, from necessity, allowed to remain some weeks, but then it was found to be entirely insoluble in ether.It was now extracted by boiling methylated spirit, and the nearly white salt deposited upon cooling of the extract mas dried and examined for barium. 0-202 grms. gave 0.063 grm. BaSO, = 18-33 per cent. barium. Oleate of baihm contains 19.59 per cent, barium. Brwsate of barium contains 1G-86 per cent. barium. The bulk of the preparation which remained undissolved by the methylated alcohol, was then decomposed by hydrochloric acid in the presence of ether. The mahogany coloured ethereal solution of fat acid was washed and the ether distilled off, leaving the acid behind ; thk solidified on cooling. Five grms. of the free acid wars melted and inclosed in a measured tube containing air standing over water. I t absorbed no oxygen during a month, showing &ah the text-book statements as to the ready oxidisability of brassic or erucio acid are unfounded.BEEF FAT. A quantity of this substance was freed from tissue by heating it in a hot air bath, and then subjecting the mass to pressure. 84 grms. of the fluid oil was saponified with caustic soda. The excess of alkali was partly neutralised with dilute sulphuric acid, and the soap which then separated was €reed from mother-liquor, which was retained for further investigation. The soda soap was converted into lead soap, which, when dry, weighed 158 grms. It mas next powdered and extracted with ether to doubtful perfection. The ethereal extract vas distilled to dipess, the lead compound decomposed by hydrochIoric acid, and ihe free fat acid taken up with ether.The ether solution was washed with water and then distilled to dryness ; the oleic acid taken up with dilute ammonia, and the solution precipitated with chloride of barium. The barium compound was isolated, washed and dried : it then weighed 29.5 grms, Assuming the lead soap to have been perfectly extracted with ether, then we find that the 84 pma. of beef fat employed consisted of 23.8 grms. of oleicacid and 60.2 grma. of solid fat acids. 2% lend salt ifiszsolu61e ita ether was decomposed by hydrochloric acid, in the presence of ether j the ether solution was distilled, and the fat acids were dissolved in, and cyyst.aDised fxom alcohol. T'be mother Zipor obtained after separation of the soda soap, mas acidified with dilute sulphuric acid, and then subjected to distillation. The distillate had a faint odow, and was feebly acid.After exact neutralisation with soda, the salt obtained upon evaporation to dryness was UnweighabIe. It was dissolved in mater and the aolution subjected to certain tests as follows :- With nitrate of silver it gave a white precipitate, which was entirely reduced upon The original white precipitate was soluble in ammonia, and waa boiling. not reprecipitated by nitric acid. It was therefore not chloride.TEE ANALYST. 17 With Bulphate of copper, it gave a precipitate which did not dissolve upon boiling With alcohol and strong aulphuz4c acid, it developed a powerful ethereal odour. With calcium chloride it gave a precipitate. With barium acetate it gave a piwipitate. A quantity was twice fused over water, to free it from salts, and was then freed from water by fusion and decantation.85.8 grms. of the white fat was saponified By boiling, during several hours, with excess of caustic soda solution. When ihoroughly saponified, the caustic solution (which was free from soap, as proved by the fact that adphuric acid in excess produced no precipitate in it) was drawn off, but to do this perfectly, it had fist to be partly neutralised by sulphuric acid. Phis solution was kept for further examination. The soda 80ap, which became white and hard upon cooling, was dissolved in much water, and precipitated by acetate of lead. The precipitate was washed with hot water, and then dried at 200'2 F., at which temperature it partially fused. The dry lead salts weighed 136 grma.The mass was powdered and extracted with ether, with the view of entirely dissolving out the oleate of lead. This, however, was found to be impracticable, although the operation was continued over several days, using more than 8 litres of ether. 2% lea& s d t diissoiuad 6y the ethw was decomposed with hydrochloric acid in presence of ether j the &her solution was washed and distilled to dryness ; the yellowish oil which was left weighed 28.7 grms. (while moist). It was converted into ammonia soap, and then into barium salt, which, when washed and dried, weighed 34 grms. (It is to be noted that 34 grms. of barium oleate correspond to 27*4 grrns. oleic acid.) I t was, therefore, presumably nearly pure oleate of barium, and this inference was confirmed by recrystallilsing a quantity of it from alcohol, and determining the amount of barium present in the purified preparation, 0.198 grm.gave *068 grm. Ba804 = 19-69 per cent. of barium againat 19-59 per cent. demanded by theory. the mixture, NUTTON DRIPPING. Tho leccd salts imolzcbte ita ether were treated as wexe those obtained from beef fat. The mother Zipor remaining after removal of the original soap, was also treated as the corresponding product from beef fat. That is to say, it wasacidified with E2S04, and distilled. The distillate had the odour of dilute butyric acid, and was acid in reaction. 1% was exactly neutralised, and the solution evaporated to dryness. Product weighed 0.053 grm. It mas dissolved in water, and upon testing the solution it was found to give all the reactions described under the notes on beef fai. I t is to be remarked, however, in connection with the fact that the solution gave -precipitates with various reagents, that the butyratea are freely soluble. OLXIC ACID. rive grms. of the oleic acid, obtained respectively from the beef fat and mutton dripping, were in each case sealed up with a measured quantity of air, standing over water during a month (June), but in neither case was any oxygen absorbed". A18 THE ANALYST. similar experiment WRS made with tho oleic acid which I had obtained from cocoa butter, with a similar result. The fact that oleic acid obtained from oil of almonds, and also that prepared from brain lecithine, do not absorb oxygen from the air, had been previously observed by Thudichums, and more recently Mr. W, Fox t has shown that oleic acid and linoleic acid from linseed oil do not, when pure, absorb oxygen. CONCLUSION OF THE SOCIETY’S PROUEEDINGS.