110 THE ANALYST. ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOODS AND DRUGS ANALYSIS. Estimation of Ethyl Alcohol in Essences and Medicinal Preparations. T. E. Thorpe and J. Holmes. (Proc. Chem. Soc., 1903, xix., 13.)-The following method is used in the Government Laboratory for estimating ordinary alcohol in essences and medicines containing essential oils and volatile substances, such ether, chloroform, benzaldehyde, camphor, and compound ethers. Twenty-five C.C. of the sample are placed in a separating funnel, diluted with water to 150 c.c., and the solution is saturated with sodium chloride. The mixture is then shaken for five minutes with 50 C.C. to 80 C.C. of petroleum spirit (boiling below 60" (2.). After standing thirty minutes, the lower layer is drawn off, extracted a second time with petroleum spirit, and introduced into a distillation flask.The petroleum layers are washed several times with saturated sodium chloride solution, the washings being added to the main solution in the flask. Distillation is then proceeded with, the distillate is made up to 100 c.c., and the specific gravity taken. To allow for the fourfold dilution of the original spirit a correction must be applied to the amount of alcohol found from the specific gravity of the distillate. The mean error for alcohol below 40 per cent. proof is +0.2, so that 0.8 per cent. must be subtracted from the percentage of proof spirit found. Details of the method of determining this error for other strengths are given, as are also the results of analyses of prepara- tions containing known quantities of ethyl alcohol.w. P. s. On the Composition of Cows' Milk. H. C. Sherman. (Joarrt. Amer. Chem. SOC., xxv., 132.)-From his monthly analyses, extending over a period of two years, of the milk from one herd of cattle, the author shows that the percentage of protein, like that of fat, varies with the season, being higher in autumn and spring than in w i n k and summer. The percentage of milk-sugar remains nearly constant through- out the year. A milk rich in fat is also generally rich in protein, the excess of protein above the normal averaging about one-third the excess of the fat. The author agrees with Richmond's conclusion (ANALYST, xxv., 225) that any deficiency of solids-not-fat is due chiefly to a deficiency in the milk-sugar, any excess above 9 per cent.being due chiefly to an excess of protein. The relation found by Richmond (ANALYST, xxvi., 310) between the ash and protein-namely, ash = 0.36 + 0.11 protein-applies very nearly to the author's results, which correspond, however, a little more closely to the formula, ash = 0.38 + 0.10 protein. A. G. L. Detection of Sesame Oil in Butter obtained from Cows fed on Sesame Cakes. A . J. Swaving. (Zeit. fiir Untersuuch. der Nalar. und Genussmittel, 1903, vi., 107-115.)--As the result of a number of feeding experiments with sesame cakes,THE ANALYST. 111 the author states that the constituent of sesame oil which gives the coloration in Baudouin’s and Soltsien’s reaotions, is not to be found in the butter-fat of the COWS so fed.In no case could a coloration be obtained. w. P. s. A Method for Comparing the Aroma of Coffee. Lebbin. (Zed. far 6feiztl. Chem., 1902, viii., 455-461.)-0ur knowledge of the constituents of coffee has hitherto been limited to data which, though they well serve to define its chemical constitution, and are useful in detecting its adulteration, afford no clear indication as to its pecuniary value. The value of a coffee is determined by the consumer almost exclusively from its richness or poverty in aroma, less notice being taken of other constituents, such as tannin, bitter principle, etc. The author has endeavoured to find out a satisfactory method of chemically determining the amount of this aroma, which is as follows : One hundred grammes of ground roasted coffee are mixed with 400 C.C. of water in a flask, and distilled over an oil-bath.300 C.C. of distillate are collected, the heat being so regulated that this quantity comes over in from one to one and a half hours. After mixing, one-half of the distillate is treated with succinic acid to remove pyridine. 50 C.C. of the rectified solution are then mixed with 50 C.C. of 7 per cent. iodic acid solution, and allowed to stand for ten minutes. The liberated iodine is Bhaken out with three successive quantities of chloroform, and titrated with i& sodium thiosul- phate solution. The number of C.C. of the latter used multiplied by six gives the quantity corresponding to the 100 grammes of coffee taken, and this the author terms the aroma value. On keeping in glass vessels, the value gradually decreases to about one-third at the end of eighty days.Kept for the same time in paper bags, the aroma diminishes to about one-eighth of the original value. When coated with sugar or shellac, very little loss of aroma takes place. The author states that the reduction of iodic acid is proportional to the amount of aroma in the coffee. It is necessary to shake out the liberated iodine with chloro- form before titrating, as a small quantity of iodine in the presence of much iodic acid gives no blue colour with starch solution. The author is at present engaged in ascer- taining the chemical composition of the constituent or constituents from which coffee derives its aroma. w. P. s. Freshly roasted coffee has a value from 75 to 105. A New Cinnamon Adulterant.W. Schmitz. (Zeit. fiir ofentl. Chem., 1903, ix., 32-33.)-The author has recently met with two samples of ground cinnamon adulterated with powdered galangal root (Rhizoma gakange). A microscopic examina- tion showed the presence of yellowish-brown splintered fragments, similar to powdered shellac. These particles were not attacked by alkalies or acids and were insoluble in alcohol, ether, and chloroform. As no yellow oil-cells could be observed, the galangal root had probably been previously extracted. w. P. s. Ferric chloride turned the fragments black. The Action of Certain Artificial Colours of the Aromatic Series on the Digestive Process. ( R z m k i Wratsch, 1902 [50] ; Biochem. Centralblatt, 1903, i., 232.)-The author has studied the influence of twenty-five A.I. Winogradow.112 THE ANALYST. different colouring matters upon the artificial peptic digestion of egg-albumin, and has found that the following twelve added in the proportion of 0.01 to 0-1 per cent. have a strong restrictive effect : Saffron, Ponceau R.R., azofuchsin, orange II., caerulein S, phloxin R. B. N., iodeoain, chrysaniline, Magdala red, azoflavin, benzo-purpurin, and cerise. The following also interfered with the digestive process, though to a much smaller extent than the others : Chinolin yellow, methylene green, acid green, iodine green, azo-acid yellow C, yellow T, naphthol yellow, aniline green, primulin, aurarnin 0, aniline orange, Martius' yellow, and metaniline yellow. C. A. M. A Reaction of Pyramidon. G. Rodillon.(Joum. P1zal.m. Chim., 1903, xvii., 172, 173.)-Pyramidon (dimethyl-amido-dimethyl-oxyquinizine) in aqueous solution has the property of giving a blue coloration with gum arabic in contact with the air at a temperature not exceeding 85" C. This reaction, which Deniges attributes to the action of an oxydase, can also be produced by the restricted action of an oxidizing agent, such as hydrogen peroxide, alkaline hypochlorites, manganese dioxide, etc. Thus, if 0.1 gramme of pyramidon be dissolved in 5 C.C. of water, and the solution treated with 1 drop of a solution of a hypochlorite, an immediate blue coloration is obtained; or the hypochlorite can be replaced by a few drops of hydrogen peroxide, but it is then necessary to heat the liquid to 60"-70" C. This reaction can be used as the basis of a colorimetric quantitative method. With ferric chloride, pyramidon gives an intense violet coloration similar to that given by phenols.C. A. M. The Reactions of Guaiacol. G. Guerin. (Jounz. Phann. Chim., 1903, xvii., 173, 174.)-Alcoholic solutions of guaiacol, treated with 1 drop of alcoholic ferric chloride solution, give a bright blue coloration, changing to green on the addition of more of the reagent. Aqueous solutions under the same conditions give brown colorations and become turbid. On adding ammonia and then an alkaline hypo- chlorite to an aqueous solution of guaiacol, and applying heat, a green coloration is obtained. An aqueous solution of guaiacol, treated with a few drops of a 10 per cent. solution of sodium nitrite, and then with 1 drop of nitric or sulphuric acid, yields a reddish-orange colour.With chromic acid solution (1 to 2 per cent.) aqueous solutions of guaiacol give brown colorations and precipitates; whilst with iodic acid solutions of the same strength they yield orange-brown colorations and orange precipitates. C. A. M. The Identification of Ordinary Tartaric Acid by Means of Lsevo-Tart aric Acid. (Zeit. anal. Cherm., 1903, xhi., 15-19.)--The following test , based on the insolubility of calcium racemate, is stated to be sensitive and applicable in all caseB. If a 1 per cent. aqueous solution of tartaric acid be treated with a slight excess of calcium acetate, crystals of calcium tartrate, CaC4H,0,.4H,0, are deposited after a few minutes. On now adding to the clear supernatant solution, J.N. Bronsted.THE ANALYST. 113 containing about 0.1 per cent. of tartaric acid, a few drops of a solution of l ~ v o - tartaric acid, a white precipitate of calcium racemate, CaC4H406.6H,0, is speedily formed. In solutions of greater concentration (0.6 per cent.) the reaction is less characteristic, whilst when the amount of tartaric acid is less than 0.1 per cent. longer standing is required for the precipitate to be formed. Tartaric acid can be detected in this way, even in the presence of a large excess of other substances giving precipitates with calcium acetate (e.g., oxalic and citric acids). Thus, the author identified tartaric acid in a 0.001 per cent. solution containing 0.5 per cent. of citric acid. In all cases the racemate crystals should be identified, under the micro- scope, if necessary after solution in dilute hydrochloric acid and reprecipitation by sodium acetate or calcium acetate.Racemic acid can be rapidly and accurately determined by precipitation from an acetic acid solution by means of calcium acetate; and, conversely, calcium can be determined by precipitation in the cold with ammonium racemate. Thus a solution of calcium chloride analysed by the usual method was found to contain 1-693 per cent. of calcium, whilst by the racemate method it yielded (1) 1.693 per cent. and (2) 1.692 per cent, of calcium. C. A. M. A Reaction of Cacodylic Acid and Cacodylates. J. Bougault. (Jozwn Pharm. Chim., 1903, xvii., 97, 98.)-A solution of hypophosphorous acid in hydro- chloric acid (strength not given) is a characteristic reagent for the identification of cacodylic acid and its salts, and for their detection in other arsenical compounds, particularly disodium methyl arsenate. A solution of 0.2 gramme of the latter salt in I to 2 C.C. of water is mixed with 10 C.C. of the reagent, and the tube closed and left for twelve hours. A strong cacodylic odour is then perceptible if the methyl arsenate contains as much as 0-5 milligramme of cacodylate. For the detection of other arsenical compounds in cacodylates 0.2 gramme of the salt is dissolved in 1 to 2 C.C. of water and mixed with 10 C.C. of the reagent. In the case of pure cacodylate no coloration or deposit of arsenic is produced in the liquid, whilst a trace of arsenic (less than 0.1 milligramme of arsenious or arsenic acid) causes a brown coloration or precipitate. Only by using very strong solutions of cacodylate is it possible to obtain a slow deposition of arsenic with this reagent. C. A. M.