152 ABSTRACTS OF CHEMICAL PAPERS ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOOD AND DRUGS ANALYSIS. Estimation of Formic Acid in Ketchup. C. A. Peters and L. P. Howdar. (J. Ind. and Eng. Chem., 1915, 7, 35-37.)-From 91 to 92 per cent. of the total amount of formic acid added to ketchup can be recovered and estimated by the process described by Fincke (ANALYST, 1911, 36, 103). The amount of distillate collected should be at least 1,000 c.c., and it is of advantage to fit a Stolzenberg tube (ANALYST, 1908, 33, 485) in the flask containing calcium carbonate, and in which the formic acid is retained, the tube serving the purpose of intimately mixing the distillate with the calcium carbonate held in suspension.w. I?. s. Analysis of Glycerophosphates. 1. Francois and E.Boismenu. ( A m . Falsific., 1914,7, 423-432.)-1n the analysis of sodium and calcium glycerophosphates estimations should be made of the water, ash, phosphorus, and the sodium or calcium, respectively. The quantity of actual monoglycerophosphate present may be estimated by Astruc’s method, in which 0.210 grm. of the substance, dried pre- viously at 150° C., is dissolved in 500 C.C.of water, and titrated with & sulphuric acid, using helianthine as indicator ; the number of C.C. of acid required is multiplied by 10 to give the percentage quantity of the mono-ester. The sample must be dried at 150° C. for the estimation of the water. The quantity of ash yielded by the substance is not of great significance, especially in the case of calcium glycerophos- phate granules, where sugar and other substances are present; the sugar, in this case, also interferes with the estimation of the mono-ester by Astruc’s method, w.P. s. Iodine (Hubl) Values of Alcoholic Liqueurs and Essential Oils. R. Marcille, (Comptes !rend., 1914, 159, 1004-1007.)-1n the estimation of essential oils in liqueurs by the French official method (distilling the sample and estimatingFOOD AND DRUGS ANALYSIS 153 Oil of aniseed in 95 per cent.alcohol ... # ? 2, 50 ,9 9 , ... Oil of turpentine in 95 per cent. alcohol ... 2 9 9 , 9 , 50 9 9 Y ? ... Absinthe liqueur . . . ... ... ... the iodine value of the distillate: ANALYST, 1913, 38, 418), it is essential that, in every experiment, the alcoholic strength of the solution under examination should be brought to some definite limit, say 50 per cent., previous to the estimation, since variations in the strength have a considerable influence on the results obtained.The flasks containing the reacting solution should be kept in a dark place during the time of contact of the Hub1 reagent with the sample, as erratic results are obtained when the mixture is exposed to light.The temperature during the time of contact has also a slight influence on the iodine absorption; for instance, an oil of aniseed yielded a value of 1-21 at 25O C. and of 1-35 at 15O C. The variations in the value due to differences in alcoholic strength and exposure to light are shown in the following table ; the figures express grms. of iodine per grm. of essential oil, except in the case of absinthe, where they show gr.ms.per litre of the liqueur : I I 1.35 1 1.54 1.62 3.19 I 2-67 1.27 i 1.80 1.67 :3€i 1 333i8 1.78 3.1 I Condensed whole milk ... ,, skim milk ... In the , In Dull In Diffused Dark. ; Light. j Sunlight. I 72.6 70.0 10.0 I 8.0 1.0 10.5 7.9 i 7.7 w. P. s. 12.0 41 14.5 42 9.1 -- Manufacture of Condensed Milk, Milk Powders, Casein, etc.R. T. Mohan. (J. Xoc, Chem. Ind., 1915, 34, 109-113.)-Milk for condensing should be rejected if the acidity is above 0.2 per cent., and 10 C.C. of it should stand at least three hours without decolorising 1 C.C. methyleno blue at 46” C. So-called “fermentation tests” are of use in checking the purity of the supplies, the Wisconsin ourd test being a good one. A pint of milk is heated in a sterilised jar to about 9 8 O F., 10 drops of standard rennet extract are added, and the jar closed and incubated for about eight hours at 98’ to 102” F.The jar is then opened, and the odour and appearance of the curd noted, which should be free from smell and the holes indicative of gas-forming organisms. The Canadian standad for condensed milk is not less than 28 per cent.milk solids, and not less than 7.7 per cent. milk fat. The following table represents the average percentage composition of condensed milks : ___ -_ - - - - Solids. Ash. Fat. 1 protein. 1 Lactose. 1 gg. 1- I -_--- - I----- I I I . .-. - -- I 1.6 2.0 1.6 5.6 6.9154 ABSTRACTS OF CHEMICAL PAPERS The greatest difficulty in the manufacture of condensed milk is to prevent the crystallisation of the lactose or cane sugar, which gives rise to “sandiness.” A decrease in concentration to prevent which is impossible, as the successful keeping of the product depends on its having less than 30 per cent. of moisture, and to effect this cane sugar must be added in a proportion of about 41 per cent.Even under the best conditions the milk sugar usually crystallises. A thick gelatinous condition of the condensed milk denotes too much milk solids and not enough cane sugar to make a syrup.Evaporuted milk in Canada is defined a8 milk from which a consider- able portion of water has been evaporated, and contains not less than 26 per cent. milk solids, and not less than 7.2 per cent. milk fat ; it contains no added sugar, and is preserved by sterilisation at 113O to 116O C.for about thirty minutes. The milk is then shaken to make it smooth and uniform, and the tins, after sealing off, are incubated for about three weeks prior to shipping, so that any leaks ” or “ swells ” can be picked out. Hard grains sometimes found in the cans consist of calcium phosphate precipitated owing to over-concentration. Plain cortdensed milk is milk evaporated about 4 : 1, which is filled into barrels and used within a few days or so by ice-cream manufacturers and confectioners.The best method of sampling con- densed milk for analysis, from which sugar may have separated, is to transfer the whole contents of the tin to a large mortar and thoroughly grind and mix it, after which a 40 per cent, solution is prepared.Solids.-For the sweetened condensed milk a quantity of the 40 per cent, solution is evaporated to dryness in vacuo or in a McGill oven (in which the product is dried at 70” C.). For the unsweetened or evaporated milk two methods are available : one by taking the sp. gr. of the 40 per cent. solution, and calculating the solids by a formula ; the other by evaporation and weighing.The determination of fat by the Rose-Gottlieb method is the most reliable of those in ordinary use, but this shows on the average 0.31 per cent. of fat too low, due to the occlusion of minute particles of fat by the precipitated casein. Modifica- tions of the ether extraction and Babcock methods are described, which, it is claimed, give quite accurate results. In the former a weighed amount of the evaporated milk, diluted 4 : 1, is absorbed on a filter-coil placed in an extraction cone, and, without any preliminary drying, extracted in 8 Soxhlet apparatus with 1 per cent.acetic acid for two hours. This removes most of the protein matter, after which the cone is washed with hot water to remove the acetic acid, dried in an air-oven at looo C . for six or eight hours, and finally extracted for eight hours with ether in the ordinary way.The paper concludes with some notes on the manufacture of milk powders and casein. H. F. E. H. Solidifying-Point of Mutton-Tallow. R. Meldrum. (Chem. News, 1915, 111, 98-99.)-The more solid glycerides separated, by means of ether, from mutton- tallow (average solidif.-pt. 41.1” C., with a rise of 2 .4 O C.), solidified at 49.7” to 50.4” C. (Dalican’s method), with a rise of 3.4’ to 4*0° C., and neither the presence of suspended matter, nor the method of stirring, had material influence on the results. The variations in the lowest point (6tzbro”) reached before the “rise” ( 2 * 5 O C.) and in the L 6 rise ” (1-8O C.) were much smaller than in the case of theFOOD AND DRUGS ANALYSIS 155 original tallow (5.5’ C.and 3.8’ C. respectively), the differences being largely due to the influence of the liquid glycerides. Such erratic results are not observed with mixtures of stearic and oleic acids. Experiments described indicated that a constant solidification-point and “rise” could be obtained if the amount crystallised per unit of time were kept constant.The glycerides examined required super-cooling to start rapid crystallisation, and each glyceride appears to have a specific temperature of solidification when super-cooled. The fact that glycerides do not reach their normal solidification-point when super-cooled appears to be due to some molecular change. The latent heat of fusion is insufficient to raise the temperature to the normal solidification-point , especially when the super-cooled mass consists of a mixture of solid and liquid substances.C. A. M. Estimation of Total Tartaric Acid and Potassium in Wines. S. Kling and A. Lassieur. (Ann. FaZsijc., 1914, 7, 410-416.)-The total quantity of tartaric acid and of potassium in wine may be estimated rapidly and accurately by precipitating the former as calcium racemate and the latter as potassium perchlorate.For the estimation of tartaric acid, 25 C.C. of the wine are treated successively with 10 C.C. of a 2 per cent. ammonium I-tartrate solution and 20 C.C. of a calcium acetate solution (16 grms. of calcium carbonate and 120 C.C. of glacial acetic acid per litre of water) ; after standing for twenty minutes, the precipitate is collected on a filter, washed, then dissolved in dilute sulphuric acid, and the boiling solution titrated with potassium permanganate solution which has been standardised against tartaric acid.From the result, expressed in grms. of potassium hydrogen tartrate per litre of wine, is deducted 0-2 grm., to correct for the amount of ammonium I-tartrate retained by the precipitate.To estimate the potassium, the ash of the wine is treated with 10 drops of water and 10 drops of perchloric acid solution (sp. gr. 1*635), and then evaporated until most, but not all, of the excess of perchloric acid has been removed. The residue is stirred with 6 C.C. of 97 per cent. alcohol, containing 0.2 per cent. of perchloric acid; the insoluble portion is collected on a filter, washed with 95 per cent.alcohol, then transferred to a crucible, dried, and heated to redness for ten minutes with 3 grms. of sodium carbonate. The perchlorate is thus converted into chloride. After cooling, the contents of the crucible are dissolved in water, filtered, 10 C.C. of & silver nitrate solution are added, and, after the addition of nitric acid, the excess of silver is titrated with thiocyanate solution. During the titration the precipitate of silver chloride should be disturbed as little as possible, since silver chloride reacts to some extent with ferric thiocyanate (ferric sulphate being used as the indicator). This method estimates the potassium present as salts of organic acids and as sulphate. w. P. s. Detection of Vanillin in Quinine Wines. A. C. Chauvin. ( A m FaZsifi., 1914, 7, 420-422.)-Lecomte has proposed a test which depends on the formation of a red zone when an alcoholic phloroglucinol solution is allowed to come into contact with a mixture of an ethereal extract of the wine and a small quantity of dilute hydrochloric acid, but the author points out that furfuraldehyde and its oxidation derivatives also give the reaction. w. P. s.