104 THE ANALYST. ORGANIC ANALYSIS. en the Separation of Oleic Acid from other Unsaturated Acids. J. Lew- koiqitsch. (Zeit. j&r Untersz~ch. der iVahr. m d Gelzussmittel, 1901, iv., 62.)-The author, replying to Farnsteiner (Zeit. far Untersuch der Nahr. und Genussmittel, 1900, iii., 537-539 ; ANALYST, 1900, 293), states that in 1899 experiments were undertaken in his laboratory with the object of testing Farnsteiner’s method, and that theseTHE ANALYST 105 proving unsatisfactory, he privately communicated the results to Farnsteiner. At the same time he sent him a sample of the oleic acid he produces on a large scale for examination by his method. As Farnsteiner found in this sample only 23-5 per cent. of oleic acid, the author considers his strictures upon Farnsteiner's method were fully justified.H. H. B. S. A Reply to the foregoing Remarks of Lewkowitsch. K. Farnsteiner. (Zeit. fiir Unterswh. dey Nahr. Z L ' P I . ~ Gemssmittel, 1901, iv., 63-65.)-The author contends that Lewkowitsch has misunderstood his meaning. His method was only intended as a test for the presence of oleic acid, and was so described in the title of the paper. He never at any time claimed for it that it was a complete method adapted for general use for the separation of oleic acid from other unsaturated acids. He, however, explains the fact that he found only 23.5 per cent. of oleic acid in the sample sent him by Lewkowitsch by supposing that the process used by him in its preparation-heating mutton-fat under pressure with lime and water-does not yield a pure product.H. H. B. 8. ___~ - The Characters of Oil of Akee. W. Garsed. (Phurm. Joum., 1900, 691.)- The oil is a yellow non-drying fat consisting, at ordinary temperatures, of a liquid and of a solid granular portion. It has a peculiar odour, and a somewhat unpleasant taste. I t consists of about 50 per cent. liquid, and 40 per cent. solid glycerides, and 10 per cent. of free fat-acids. The acids contain oleic acid, and either a mixture of, or near homologues of, palmitic and stearic acids. In the following table the constants of nkee oil are compared with those of olive oil and palm oil : Specific gravity . . . Melting-point . . . Solidifying-point . . . Hehner value . . . Saponification value Reichert value ... Iodine value . . . Acid value . . . ...Akee Oil. Palm Oil. Olive Oil. 99"-100" C., 0.857 98"-99" C., 0.8586 15.5" C., 0.914-0.917 (Water at 15-5" C. = 1.) 2 5"- 3 5" 2 7"- 42 -5" 2 -5" 20" 21"-27" + 2" t o -4' 93 94 '2 - 97 95.4 194.6 196.3-2023 185-196 0.9 0.5 0.3 49.1 51-5204 81-6-84 *5 20.1 - - MIXED FATTY ACIDS. Akee Oil. Palm Oil. Olive Oil. Specific gravity at 99" c. ... ... 0.8365 0.8369 0.843 Melting-point . . . 42"-46" 47~7~-52" 2 2'- 2 6" (Water at 15.5" C. = 1.) Solidifying-point . . 40"-38" 44445" 2I0-24O Saponification value 207.7 206'5-207.3 Iodine value ... 58.4 - 86.1 -90.2 A. G. L. Test for Sesame Oil in Vegetable and Animal Oils. Tambon. (J. Phawn. Chim., 1901, xiii., [6], 57; through Chem. Zed. Rep., 1901, 40.)-The reagent106 THE ANALYST. consists of 3 or 4 grammes of pure dextrose dissolved in 100 grammes of hydro- chloric acid.I n a stoppered tube 7 or 8 C.C. of the reagent are shaken for two or three minutes with 15 C.C. of oil, the whole is heated till it begins to boil, shaken again, the tube closed and allowed to cool. The smallest trace of sesame oil causes the liquid to appear pink, with a violet cast, which quickly changes to cherry-red. If 1 to 5 per cent. of sesam6 are present, the colour develops in a few minutes ; with 10 per cent. it shows immediately, and gradually becomes stronger. The reaction also succeeds with fatty acids. F. H. L. Halphen's Reaction for Cotton Oil. Presence of Cotton Oil i n American Lard. P. Soltsien. (Zeits. ofentl. Chem., 1901, vii., 25; through Chem. Zed. Rep., 1901, 52.) -In consequence of Raikow's statements and his own investigations, the present author has now reverted to the use of amyl alcohol in this test.He adds 20 per cent. of a 1 per cent. solution of sulphur in carbon bisulphide to the oil or fat, and then introduces about one-half the total volume of amyl alcohol. Light at first hastens the appearance of the colour and then bleaches it. F. H. L. The Characteristics of Lipase. J. H. Eastle and A. S. Laevenhart. (AmeT-. Chem. Jounz., 1900, xxiv., 491-525.)-Ethyl butyrate is so rapidly hydrolyzed by fipase that it can be used to measure the activity of the enzyme. In their experiments the authors prepared the extract of lipase by macerating 10, 20 or 50 grammes of the fresh pancreas of a pig with coarse white sand, extracting it with water or glycerin, and diluting to 100 C.C. In each case 4 C.C.of water, 0.1 C.C. of toluene (as a preservative), and 0.26 C.C. of ethyl butyrate were heated for five minutes at 40" C., and then, after the introduction of 1 C.C. of the extract, for a further forty minutes, after which the liquid was titrated with & potassium hydroxide solution. In comparison with the pancreas, the other tissues of a pig showed the following relative degrees of activity : pancreas, 1.0 ; liver, 2-93 ; kidney, 0.50 ; subrnaxillary gland, 0.36. Comparative experiments with the extracts from the livers of other animals, in which the action of the enzyme was continued for fifteen minutes, gave the following amounts of hydrolysis : Pig, 8.66 ; sheep, 4.77 ; duck, 2.iO ; ox, 2.20; and chicken, 1.95 per cent.On repeated filtration of the extracts, the lipase is almost conipletely removed from the liquid. It is more stable than is usually supposed, and the extract can be kept in a refrigerator for several days without losing its activity. Ethereal salts are most rapidly hydrolysed by lipase at 40" C., whilst the enzyme is destroyed at 60"-70" C. Most of the common antiseptics are injurious, and, in particular, sodium fluoride, hydrofluoric acid, and acids in general. The authors find that the velocity of the reaction is not proportional to the active mass of the ethereal salt, but is nearly so to the concentration of the enzyme. In the case of ordinary extracts the reaction is not complete, though it is practically so when very active extracts of the enzyme are used, or when the proportion of etherealTHE ANALYST.107 salt is very small, The co-efficient of the velocityis not constant, but decreases with the progress of the reaction. By means of lipase, the authors have effected a synthesis of ethyl butyrate from butyric acid and alcohol, and from this conclude that the action of the enzyme is reversible. They consider that this discovery may throw light upon the question of the storage and utilization of fatty reserve material by plants. C. A. M. Notes on the Examination of Beeswax. G. Buchner. (Chenh. Zeit., 1901, XXV., 21 and 37.)-Valuation of wax becomes more difficult when the Hiibl constants are normal or nearly so, and the qualitative tests hint at impurities. I n such cases the author's process (Chem.Zeit., 1895, xix., 1422) is best employed to ascertain the " Buchner number " ; Werder's recent method (Zoc. cit.) for the determination of neutral matter can also be recommended. Occasionally- the constants are abnormal, but the qualitative tests suggest purity. In general the limits laid down by Hiibl and Allen (19 to 21, 73 to 76, 92 to 97, 3.6 to 3.8) are correct ; sometimes, however, one obtains 17.5 to 21, 70 to 78,87.5 to 99. The soft agreeably-smelling Ghedda wax (from British India and Bombay) often gives '5'33J 88-35, 93-68, 17.6 ; while Ahrens and Hett have obtained similar figures from humble-bee and cicada waxes, Ten per cent. of Ghedda wax added to a normal product would yield acid and ester values 18.53 and 76.3 ; 20 per cent. would show 17.06 and 77.6; 50 per cent., 12.65 and 81.67; yet each would be pure wax.African wax also gives abnormal constants. The author has received a sample of comb from Afrat, near Mogador. When this was purified by repeated melting it gave : specific gravity at 15" C., 0.961 ; melting-point, 64" to 65" ; solidifying-point, 61'; iodine value, 11.65; and the average Hiibl constants 19.92, 79.43, 99-35, 3-98. The stearic acid test showed a slight amorphous deposit in twenty-four hours, as almost all African waxes do ; but no foreign matter could be detected. Chemically bleached wax of undoubted purity sometimes exhibits a high acid value, as the following figures indicate : 23.19 to 26-23, 69.00 to 73.93, 95.00 to 98.45, 2.70 to 3.20. It is clear that the Hub1 constants are no longer suficient by themselves to enable the purity of beeswax to be judged. Qualitative tests must also be employed. The presence of 1 per cent, of stearic acid may correspond with the addition of 15 per cent. of " composition "; and often only 5 or 10 per cent. are mixed with the wax, for even this small amount of factitious matter represents a considerable annual profit to the manufacturer. F. H. L.