442 ABSTRACTS OF CHEMICAL PAPERS ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOOD AND DRUGS ANALYSIS. Apparent Effect of Acetic Acid upon the Constants of Butter-Fat. C. Bahlman. (J. I n d . and Eug. Chem., 1915, 7, 680-68l.)-A convenient method for the estimation of fat in ice-cream consists in weighing 9 grms. of the melted sRmple into a Babcock milk-bottle, adding 20 C.C. of glacial acetic acid, and then 10 C.C.of sulphuric aoid, and proceeding as in the ordinary estimation of fat in milk. The presence of the acetic acid prevents the charring action of the sulphuric acid on the sugar. The reading of the fat column in the neck of the bottle, multiplied by 2, gives the percentage quantity of fat in the sample. Attempts to prove that the separated fat consisted of butter-fat, by removing the fatty layer and subjecting it to analysis, were unsuccessful.The refractometer values obtained were always much lower than those shown by butter-fat, whilst the Koettstorfer and Reichert- Meissl values were too high. This was due to the presence of acetic acid in the fat. The acid may be expelled by heating the fat at 95OC. for one hour, and normal analytical results are then obtained if the fat consists of butter-fat.When the fat is separated from dairy products by decomposition with sulphuric or hydrochloric acid, no appreciable quantity of acid is retained in the fatty layer. w. P. s. Estimation of Ash in White Bread. J. W. Filippo and W. Adriani. (Chem. Weakblnd, 1915,12,570-576.)-0wing to the volatility of the sodium chloride, the amount of ash in bread as estimated by ignition is inaccurate.The sodium chloride will be about 0.5 per cent. too low, and the ash free from sodium chloride about 0-2 per cent. too high. The most accurate method is to estimate the sulphated ash, and to deduct therefrom the amount of sodium sulphate corresponding to the sodium chloride, the latter being estimated by ignition with calcium oxide and titration by Volhard's method.Finally, a, deduction of 0.09 per cent. is made for the ash of the yeast, and the result is multiplied by the empirical factor $, to obtain the percentage of ash in the dry flour. C. A. M. Test for Cocaine. L. A. Ryan. (J. Amer. Chent. SOC., 1915, 37, 1960.)- M. Goeldner (Zeitsch. anal. Chem., 1901, 40, 820) states that a delicate test for cocaine consists in the formation of a cornflower-blue colour when a trace of thisFOOD AND DRUGS ANALYSIS 443 substance is added to 0.01 grm.of pure resorcinol in the presence of 6 or 7 drops of pure concentrated sulphuric acid. The author fails to confirm this, and finds that if chemically pure sulphuric acid is used, no such colour is developed; but that if the acid is slightly contami- nated with nitrous or nitric acid, the blue colour is formed.So delicate, in fact, is this test that 0*0000001 grm. of nitrogen as potassium nitrate, when evaporated to ,dryness and the residue moistened with chemically pure sulphuric acid, yields a blue coloration on the addition of a trace of solid resorciuol. This reaction would be valuable in detecting traces of nitrate or nitrite in the course of waher analysis.H. F. E. H. Official .Method for Determining Crude Fibre as Applied to Cottonseed Meal. (J. Izcl. and Eng. Chew., 1915, 7, 676-679.)-The dry fat- free residue from 2 grms. of material is boiled for half an hour with 200 C.C. of 1.25 per cent. sulphuric acid, the volume being kept constant by using round-bottomed flasks filled with cold water supported on the top of the beakers.At the end of this time the solution is not filtered, but 200 C.C. of boiling 3.25 per cent. sodium hydroxide are added, and the boiling continued for thirty minutes. I t has been found by experiment that by use of this strength of sodium hydroxide a solution of 1.25 to 1-27 per cent. sodium hydroxide is available for the second boiling, the advantage of this being that one filtration only is eventually necessary.The residual fibre is filtered with the aid of suction on a Buchner filter, and washed with boiling water, followed by a 1.25 per cent. solution of hydrochloric acid until the washings are acid. This treatment is followed by hot water washings continued until free from chlorides, and finally the filter is washed several times with alcohol. The residue on the paper is then transferred with the aid of a small amount of 80 per cent.alcohol to a prepared Gooch crucible, packed with a pad of asbestos about 1 mm. thick, previously heated to redness. The whole is then dried at 105O t o 110’ C . , cooled and weighed, the ash being subsequently deducted. The filter-paper recommended is the No.575 (hard) Schleicher and Schull. It is found that loss of crude fibre may occur when linen is used a8 a filter, while asbestos may lose weight, and thus cause the results to be too low. Schleicher and Schull paper No. 597, when torn into large pieces, dissolves to the extent of about 3.5 per cent. during thirty minutes’ boiling in 1.25 per cent. sodium hydroxide; while this class of paper, if ground so as to pass a 40-mesh sieve, dissolves to the extent of 2-8 per cent.When this filter-paper is boiled in both acid and alcohol, the loss in the case of the larger pieces is 11.5 per cent., and with the powdered paper it rises to 31.5 per cent. A paper of this character is thus quite unsuitable for the separation of the fibre. S.K. Francis. H. F. E. H. Analysis of Pulvis Rhei Cornpositus (Gregory’s Powder). G. D. Elsdon. (Pharm. J., 1915, 95, lOO-lOl.)-According to the British Pharmacopoeia of 1914, Gregory’s powder consists of light magnesia, 66 ; powdered rhubarb root, 22 ; and ground ginger, 12 parbs ; this differs slightly from the formula prescribed in the 1898444 ABSTRACTS OF CHEMICAL PAPERS edition (magnesia, 6 ; rhubarb, 2 ; ginger, l), but the difference is not sufficient t o invalidate the results given below, which were obtained by analysis of the 189% powder.Moisture is estimated by drying the sample at 100' C. ; the loss in weight (not due entirely to moisture) usually varies from 2 to 5 per cent. The ash of the sample consists of magnesium oxide, together with the ash of the rhubarb and ginger ; the calculated ash, allowing 10 per cent.for rhubarb and 5 per cent. for ginger, is 67.5 per cent. Fifteen commercial samples examined gave from 57.1 to 72.5 per cent. The alkalinity of the ash, expressed as MgO, is usually about 4.5 per cent. less than the percentage of ash. Carbon dioxide may be estimated by rinsing 0.5 grm. of the powder into a nitrometer over mercury, adding 5 C.C.of hydrochloric. acid, and reading off the volume of the liberated carbon dioxide; this volume i s corrected for temperature, pressure, and sohbility. The author finds that the solubility varies with the amount of magnesium oxide which has been dissolved, and gives the following table showing the correction to be applied : Grm.of MgO dissolved in 10 c c. of HCl. 0.00 0.15 0.25 0.35 0.50 C.C. of C 0 2 dissolved at 65 F. 7.5 6.3 6.1 5.6 5.1 Gregory's powder should not contain more than 3 per cent. of carbon dioxide, and the presence of more than 5 per cent. must be considered as constitutiug adulteration. The combined amounts of rhubarb and ginger can be obtained approximately from a consideration of the quantities of ash and magnesium oxide in the sample.Confirmation may be obtained as follows: The quantity of water- soluble constituents is estimated by treating 1.2 grms. of the powder with 60 C.C. of cold water for twelve hours, then filtering the mixture, evaporating 50 C.C. of the filtrate, and drying the residue to constant weight. Another portion of 1 grrn. of the powder is treated with 70 C.C.of acetic acid for thirteen hours, the insoluble portion then collected on a filter, washed once with water, and dried. The weight of the insoluble matter, added to the weight of the aqueous extract, after adding 10 per cent. of the total weight for the average moisture in ginger and rhubarb (this figure is very constant), gives the amount of ginger and rhubarb in the sample.This depends on the fact that dilute acetic acid extracts nearly the same amount from rhubarb and ginger as does water, but dissolves the magnesium oxide in addition. The relative amounts of rhubarb and ginger may be found in the following manner: The amount of aqueous extract having been estimated, the alcoholic extract is obtained in a similar way, using industrial methylated spirit of 64 over- proof for the extraction.From the percentage extracts of the sample, the percentage extracts of the combined rhubarb and ginger mixture contained therein may be calculated. Thirty samples of ginger examined by the author gave an average of 13.3 per cent. of aqueous extract, 5.8 per cent. of alcohol extract, the quantities being remarkably constant.The amount of extracts obtained from specimens of rhubarb varied more widely, fifteen samples giving from 30.0 to 44.0 per cent. of aqueous extract,FOOD AND DRUGS ANALYSIS 445 and from 28.8 to 36-4 per cent. of alcohol extract; the average quantities may be taken as being 38.0 and 33.0 per cent., respectively. Taking 38 and 13 as tho percentage aqueous extracts of rhubarb and ginger, and 33 and 6 as the percentage alcohol extracts, respectively, and knowing the aqueous and alcohol extracts of the sample, the composition of the sample may be calculated from either of these figures ; the figures for the alcohol extracts, however, give the more accurate results.w. P. s. Detection of Hydrogen Peroxide in Milk. J. T. Darlington. (J. I d and Eng. Chem., 1915, 7, 676.)-Paraphenylene diamine or benzidine will detect 0.00075 per cent. of hydrogen peroxide in milk, the former being perhaps the more delicate reagent. Titanic acid, vanadic acid, or starch and potassium iodide, will not detect less than 0.003 per cent.After eighteen hours standing at room temperature, hydrogen peroxide can no longer be detected, although it may have been added in large quantity to milk.G. C . J. Estimation of Phenacetin and Salol in Admixture. W. 0. Emery, G. C. Spencer, and C. C. LeFebvre. ( J . Ind. and Eng. Chem., 1915, 7, 681-684.)- Two methods are described. In the first, the phenacetin is converted tetnporarily into phenetidine sulphate by digestion with sulphuric acid, the sulphate is treated with chloroform to remove the salol, then reconverted into phenacetin, and the latter isolated and weighed; the salol is estimated by difference.The second method consists in converting the 551101, by treatment with sodium hydroxide, into sodium salicylate and phenolate, separating the phenacetin by extraction with chloroform, and estimating the salol by titration with bromine. First Method.-If the phenacetin and salol are mixed with other substanct-s in pill or tablet form, a portion of the sample is extracted with chloroform, the chloro- form extract evaporated below 60' C., and the residue weighed.This residue is then treated with 10 C.C. of dilute sulphuric acid (1 : lo), and the mixture heated on a boiling water-bath until the volume of the liquid is reduced to 5 C.C. ; 10 C.C.of water are then added, the liquid evaporated to 5 c.c., and the addition of water and the evaporation again repeated. The residual solution is rinsed into a separa- ting funnel with 20 C.C. of water, and extracted with three successive quantities (15 c.c., 10 c.c., and 5 c.c.) of chloroform; as they are separated, the chloroform extracts are washed with 5 C.C. of water in a second separating funnel.The aqueous solution, to which the wash water is added, is treated with sodium hydrogen carbo- nate in small portions at a tjme until an excess of the latter remains at the bottom of the funnel. Twenty-five C.C. of chloroform are now added, followed by 5 drops of acetic anhydride for every 0.1 grm. of phenscetin known or believed to be present. The mixture is shaken for a short time, the chloroform layer then drawn off into a, separating funnel, washed with 5 C.C.of water, and distilled until about 20 C.C. of chloroform have been collected. This distilled chloroform is used for extracting the mixture a second time, and a third extraction is made in a similar way. The total chloroform extract obtained is evaporated on a water-bath, the residue evapo-446 ABSTRACTS OF CHEMICAL PAPERS rated several times with the addition of small quantities of chloroform, then dried over calcium oxide to remove the last traces of acetic anhydride, and weighed.Second Method-A weighed portion of the mixture, containing not more than 0.1 grm. of salol, is heated on a water-bath for five minutes with 10 C.C. of 2.5 per cent.sodium hydroxide solution; the solution is then cooled rapidly, transferred to a separating funnel, and extracted with three successive quantities of chloroform, using 20 C.C. each time. The chloroform extract is washed with 5 C.C. of water, filtered, evaporated, and the residue of phenacetin weighed, The alkaline aqueous solution is now transferred to a stoppered bottle, diluted with water to about 200 c.c., and a n excess (about 45 c.c.) of potassium bromide-brornate solution and 10 C.C. of con- centrated hydrochloric acid added. The mixture is shaken for one minute, and then at intervals for thirty minutes ; at the end of this time, 10 C.C. of 15 per cent. potassium iodide solution are added, the mixture is shaken for fifteen minutes, and titrated with 7 thiosulphate solution. Twelve atoms of bromine are required for each molecule of salol; therefore each C.C. of bromide-bromate solution corre- sponds with 0*002548 grm. of salol. Results of numerous experiments are recorded, showing that the two methods are trustworthy; in most cases the quantities of phenacetin and salol recovered varied from 99 to 100 per cent. of the amounts present, respectively . w. P. s.