116 EXPERIMENT STATION EECORD. 



Quantitative method for fatty acids in fats and oils, K. Braun {Seifen- 

 fabrikant, 29 {1909), p. 11J,0; (ibs. in. Clicm. Abs., // {1910), No. 3, pv. 392, 393).— 

 Saponify about 0.5 gm. of the material with 30 cc. of alcohol and 0.5 gm. of 

 potassium hydrate, evaporate off the alcohol, dissolve the residue in 20 ce. of 

 water, neutralize with sulphuric acid, using methyl orange as indicator, transfer 

 the solution to a 200 cc. flask, and add an excess of decinormal silver nitrate. 

 Then add about 10 gm. of sodium sulphate (anhydrous), make the solution up to 

 Ibe 200 cc. mark and filter. To 100 ce. of the filtrate add 5 cc. of iron alum solu- 

 tion (saturated in the cold and treated with nitric acid) and titrate with 

 decinormal ammonium sulphocyanid solution. From this calculate the number 

 of cubic centimeters of decinormal silver nitrate solution used. Each cubic 

 centimeter of this equals 0.001266 C3H2 (the theoretical residue left when the 

 fatty acid is subtracted from the fat), and 100 per cent minus the percentage of 

 C3H2 equals the percentage of fatty acids. The fats and oils must necessarily be 

 free from chlorids. 



The determination of the acid and saponifying numbers of dark fats and 

 oils, F. Marx {('hem. Ztg., 34 {1910), No. 16, p. 12',; ab><. in Pharni. Zifi.. .-,5 

 {1910), No. 20, p. 20-',). — A new method is described, as follows: Weigh 2.5 gm. 

 of the fat into a 600 cc. porcelain dish, stir in 50 cc. of neutral alcohol, add 6 to 

 8 drops of phenolphthalein, and titrate the free fatty acids. Pour the mixture 

 into a 250 cc. flask, washing the residue remaining in the porcelain dish with 20 

 cc, and then with 10 cc, of pure benzol into the flask. Then add 25 cc. of one- 

 half-normal alcoholic potash solution, boil for I hour, pour the solution back into 

 the porcelain dish and with the aid of hot alcohol add 5 to 6 drops of phenolphtha- 

 lein and titrate back with acid to estimate the unused alkali. 



The detection of fish oils in vegetable oils, (). Eisenschiml and II. X. Cop- 

 THORNE {■Jour. Indus, and Engin. Chcni., 2 {1910), No. 2, pp. -'i3-'.',5). — The 

 authors sought to find a reliable qualitative and quantitative method for fish 

 oil in linseed oil, and found a qualitative test which is deemed entirely suitable 

 for detecting fish oils in admixtures with vegetable oils or similar products. In 

 this. 100 drops of the oil are dissolved in 3 cc. of chloroform and 3 cc. of glacial 

 acetic acid. Bromin is then added slowly to the n^ixture and after 10 minutes 

 the test tube is placed in boiling water. Vegetable oils clear up, while fish oils 

 remain cloudy. In the case of boiled oils it is necessary to remove the metals 

 before making the test. Linseed oils heated up to or higher than 260° C. do not 

 give the test. 



Fat staining methods, P. Eisenberg (Arch. Path. Anat. a. Physiol. [Virchon-], 

 199 {1910), No. 3, pp. 502-5J,2). — This is a chemical and techno-histological in- 

 vestigation on the staining of fats in animal tissues. 



The significance of the biological detection of vegetable agglutinins and 

 hemolysins, II. Kobert {Landw. Vers. Stat., 11 {1909), No. J,-5, pp. 2.')'li-2l)i\ . — 

 A discussion of the use of these biological reactions for detecting adulterations 

 in vegetable products. 



Photochemical formation of formaldehyde in green plants, S. B. Schryver 

 {Proc. Roy. Soc. {London}, 8er. B, S2 {1910), No. B 55J,, pp. 226-232; abs. in 

 Pharm. Jour. [London], J,, ser., 30 {1910), No. 2.',19, p. 238).— The following 

 lest serves to demonstrate the production of formaldehyde in plants: To 10 cc 

 of the solution add 2 cc. of a 1 per cent (freshly made and filtered) pheuyl- 

 hydrazin hydrochlorid solution, 1 cc of a 5 per cent potassium ferricyanid solu- 

 tion, and 5 cc. of hydrochloric acid. If formaldehyde is present a bright red 

 color is developed. 



