80 ABSTRACTS OF CHEMICAL PAPERS ORGANIC ANALYSIS. Detection of Acetone by Frommer's Test. N. 0. Engfeldt. (Bed klin. Woch., 1915, 52,458-459 ; through J . Chem. Soc., 1915,108, ii. 849-850.)-Frommer's test depends upon the condensation of acetone with salicylaldehyde in presence of alkali hydroxide to form the red di-o-hydroxy-distyryl ketone. Ten C.C. of the urine or other liquid to be tested are treated with 1 grm.of solid potassium hydroxide, and, without waiting for the alkali to dissolve, 10 drops of a 10 per cent. solution of salicylaldehyde in alcohol are added, and the mixture is heated to 70' C. If acetone is present, a, purple-red zone appears at the junction of the two liquids. The test will detect 0.05 mgrm. of acetone in 10 C.C. of water, but the author finds that it may be rendered more sensitive and capable of detecting 0.001 mgrm. of acetone in 10 C.C.when modified as follows: Ten C.C. of the distillate from the urine are mixed with 5 grms. of solid potassium hydroxide and 5 drops of concentrated salicyl- aldehyde solution. The test-tube containing the mixture is placed in a water-bath at 50" C., and the water is heated gradually to boiling.As the potassium hydroxide dissolves, a crystalline mass is formed which, in the presence of acetone, is coloured bright-red. Formaldehyde, acetaldehyde, formic acid, lactic acid, phenols, and alcohol do not give the red coloration, but acetoacetic acid and P-hydroxy-butyric acid yield red-coloured compounds with the test. On account of its sensitiveness, the test is not suitable for clinical purposes.Distribution Co-efficients and Velocity of Extraction of Certain Organic Acids. J. Pinnow. (Zeitsch. anal. Chem., 1915, 54, 321-345.)-The distribution co-efficients between water and ether for acetic acid at 15' C., succinic acid at 1 5 O ,ORGANIC ANALYSIS 81 20°, and 25.5' C., citric, tartaric, lactic, and oxalic acids at 15', 25*5', and 27.5' C.have been determined by the author, who has also investigated the velocity of extrac- tion of these acids from their aqueous solution by means of ether in the Parthiel- Rose apparatus (cf. ANALYST, 1902, 27, 103). The extraction practically follows the formula of monomolecular reactions ; it is,- within certain limits,- inversely qropor- tional to tbe volume of liquid extracted and also to the distribution co-eficient a t 27' C.The distribution co-eacients at 2 7 O C. are: Citric acid, 153; succinic acid, 7.58; malic acid, 70.9 ; lactic acid, 11-28 ; oxalic acid, 13.9. If the distribution co-efficients of the acids at 2 7 O C. be divided by 0.04, the time (in minutes) required for the approximately complete (99 per cent.) extraction of the acids from 30 C.C.of solution is obtained. The addition of sulphuric acid up to one-sixth grm. molecule per litre is recommended in the case of oxalic acid solutions, and a small addition of sulphuric acid is also advantageous in the case of the other acids. w. P. s. Analysis of Textiles. Pontio. (Comptes. rend., 1916, 162, 81-83.)-The microscopiial identification of textile fibres by the process established by Vetillard may be greatly facilitated by a preliminary chemical purification of the samplea. Portions ranging from 1 to 3 grms.(the warp and weft being treated separately) are boiled with 150 C.C. of a 2 per cent. solution of caustic soda for fifteen minutes ; the coloured liquid is poured off and replaced by a further quantity of the same alkali, wibh which the fibre is again boiled for fifteen minutes. After thorough washing, the fibre is heated with 25 C.C.of sodium hypochlorite solution (sp. gr. 1.007) diluted with 75 C.C. of water. The liquid is brought to the boil for exactly two minutes and then poured off. The fibre is treated with a dilute solution of sodium bisulphite for five minutes, then thoroughly washed with water.For the microscopic examination, a slight modification of Vetillard's staining reagent is desirable ; in the original recipe the iodine was too weak and the sulphuric acid too strong. The modified reagent consists of two solutions : (A) Potassium iodide, 3 grms. ; water, 100 grms. ; resub- limed iodine in excess. (B) Sulphuric acid (sp. gr. 1.767). 24 grms.; mixed with water, 16 grms.; then, after cooling, glycerol (sp. gr. 1.169), 16 grms. These reagents should be made up fresh every month. The fibres! having been pressed dry between blotting-paper, are steeped in a drop of the solution ( A ) on the microscope-slide. The iodine is allowed to act for two minutes and pressed out again with blotting- paper. In the examination of several fields, the coloration, the shape and structure of the fibres, and of the woody fibres, the epidermal cells, the parenchyma, the woody vessels, etc., are care- fully noted and photomicrographs are taken of representative fields, using autochrome plates.The magnifying power of the apparatus being known, the dimensions of the various elements may be measured on the photographs. The preliminary treatment above described in no way changes the structure of the fibren, while clearing out all the overlying impurities. The coloration with the iodine stisin remains perfectly characteristic, the lignified portions still reacting in the normal way, and the struc- tural details are made more distinct. The separation of the fibres from one another is greatly facilitated and compound filaments only remain in the case of a few highly lignified materials, such as jute. The fibre is then mounted in a drop of solution (B). J. I?. B.