260 THE ANALYST. ABSTRACTS Prot eolysis OF PAPERS PUBLISHED IN OTHER JOURNALS. FOODS AND DRUGS ANALYSIS. in Cow’s Milk preserved with Formaldehyde. G. Tice and H. C. Sherman. (Jou/m. Awzer. Chem. Xoc., 1906, xxviii., 189-194.)-Analyses of samples of milk preserved with formaldehyde show that very considerable proteolysis takes place after some time, the albumin being largely digested before the amount of casein is appreciably reduced, though as digestion proceeds and the casein diminishes the proportion of nitrogen existing as albumin and syntonin changes but little, the increase appearing first in the proteoses, then in the peptones and amino-compounds. Only slightly more nitrogen was precipitated by phosphotungstic acid than by tannin, indicating the presence of only small amounts of diamino-acids.Relatively large amounts of proteoses have been found at a rather advanced stage in the digestion, result entirely different from that of bacterial digestion of milk. I n one case, while 95 per cent. of the casein had been digested, less than 4 per cent. of the original lactose was lost, as compared with milks preserved with sodium fluoride or salicylate or hydrogen peroxide, in which, after 25 to 30 per cent. of the lactose had been destroyed, no marked digestion of the casein was noticed, proving the effect of an added antiseptic in determining the character of the fermentation subsequently undergone. W. H. S. The Determination of Proteids in Milk. Trillat and Sauton. ( A m . de Chim. anal., 1906, vol. 11, pp. 205-207.)-The method is based upon the fact that formaldehyde renders the proteids of milk insoluble.Five C.C. of the milk are diluted to 25 C.C. with water, and the liquid boiled for five minutes, then treated with 5 C.C. of commercial formalin, boiled for two or three minutes longer, and allowed toTHE ANALYST. 261 ... ... ... Cow's milk 39.11 34.33 19.50 Ditto, with 10 per cent. of water Ditto, with 50 per cent. of water ... Goat's milk ... ... 36.64 Ass's milk ... ... ... 21-03 ... ... Colostral milk (cow) 11.00 On the Use of the " Silver Value " for the Deteetion of Cocoanut Oil in Butter. F. Jean. (Ann. de Chim. awl., 1906, vol. 11, pp. 121-124.)-The method devised by Wijsrnan and Reijst (ANALYST, xxxi., 158) has 'been tried by the author upon twelve samples of doubtful butter, and as the second silver value was invariably lower than the first, the conclusion arrived at was that the butters were abnormal, but free from cocoanut oil.On the other hand, the method of Muntz and Coudon (ANALYST, xxx., 155) gave ratios of 22 to 36, which, in conjunction with the other analytical values, pointed to the presence of cocoanut oil. Thus the following results were obtained with two of the samples : 1-1- I I Butter, No. 1 ,, No. 3 228 27-2 229 1 26-2 35 35 5.06 4.95 3 + 3 . zg 3 + 5% c) m 4-81 4-50 Mnntz and Coudon's Method. 0 0 + X 0 -3 I;, 2 4.81 4.50 1.76 1.14 36 26 Abnorm a1 Abnormal In order to determine the cause of these contradictory results, the author prepared mixtures of pure butter with 10 per cent. of a cocoanut-oil mixture in262 THE ANALYST. common use for adulterating purposes, and with 10 per cent.of a mixture in equal parts of cocoanut oil, karitb, butter, and lard, and obtained the following results : Adulterated Butter, No. 1 9 , ,, No. 2 32.0 ' 220 ' 26.4 32.5 1 216 1 26.7 4.72 4.69 The presence of the cocoanut oil (3.4 and 2.5 per cent. respectively) is here plainly shown by the ratio in Munte and Coudon's method, whereas from the silver values both samples would have been judged to be pure. Hence the author concludes that the method of Wijsman and Reijst can only be of value as a confirmative test, and that when it gives negative results cocoanut oil in admixture with other fats may still be present. C. A. M. The Characteristics of Karite Butter. F. Jean. ( A m . de Chim.aizaZ., 1906, vol. 11, pp. 201-203.)-KaritB or fulwar butter is extracted from the seeds of Bassia butyracea, a tree growing in the Himalayas and in the tropical zone of Africa. According to the author, large quantities of the seeds and of the fat are sent to England, the latter being used in the adulteration of butter, lard, and cocoa-butter. The kernels examined by the author had the following composition : Water, 10.05 ; fat, 35.49 ; soluble extractives, 26.44 ; tannin, 3.2 ; ash, 2.50 ; and cellulose, 22.52 per cent. The butter is a white, paste-like fat, with a slight odour and an astringent taste. I t can be purified by a method similar to that used in deodorizing cocoanut oil for food purposes. The following analytical values were obtained with a sample of the fat extracted with petroleum spirit and of fat prepared by the natives by crushing the nuts with water : Oleorefracto- Melting- Acid Saponifica- Iodine Reichert- Hehner Fat.y2h.at point. Value. tion ~ a l u e . Value. :.$$ ~~~~ Value. Extracted in Q C - laboratory +22" 30 - 175-176 - 2.6 - Asimported +18" 30 9 175 19.75 1.19 trace 91.2 The fat consisted of 69.28 per cent. of solid fatty acids, 21-92 per cent. of liquid The fatty acids, separated by Renard's Neither caproic nor caprylic acid was present in the acids, and 8-85 per cent. of glycerin. method, melted at 67.8" C. butter. C. A. &I. The Action of Flour, etc., on Hydrogen Peroxide. W. Bremer. (Zeit. Untersuch. Nahr. Genussm., 1906, xi,, 569-577.)-The author's experiments show that the method proposed by Wender (ANALYST, 1906, xxxi., 73) for the valuation ofTHE ANALYST.263 flours is at present of little use. The evolution of oxygen is erratic, equal weights of the same flour yielding varying volumes of gas, and the quantity is not proportional to the amount of flour employed, or to the percentage of bran in the flour. The power of decomposing hydrogen peroxide is diminished if the flour be heated previously to a temperature of 98' C., a moist heat having more effect than a dry heat. As both the aqueous extract and the insoluble residue, obtained on extracting bran with water, decompose hydrogen peroxide, the assumption is raised that more than one constituent of the bran is capable of causing the decomposition. The presence of mercuric chloride or of hydrochloric acid inhibits the reaction, as does also that of alcohol.Whilst well-washed gluten decomposes hydrogen peroxide to a slight extent, no action was noticed in the case of aqueous solutions of diastase. w. P. s. Formic Acid as a Preservative of Lemon-Juice. Von Kiittner and Ulrich. (Zeit. ofentl. Chew., 1906, xii., 201-207.)--The deterioration of fresh lemon-juice due to the formation of acetic acid may be prevented by the addition of from 0.1 to 0.4 per cent. of formic acid. The addition, of course, increases the acidity of the juice, and the results of experiments are given which show that the formic acid distils over quantitatively with the other volatile acids present in the juice. w. P. s. Composition of Tomatoes and Tomato-Juice. W. Stuber.(Zeit. Unter- such. Nahr. Genussm., 1906, xi., 578-581.)-The following results were obtained on the analysis of two samples of tomatoes and their respective juices : -_ - Water . . . ... ... ... Ash ... ... ... ... Alkalinity of ash (c.c. acid) ... Nitrogen ... ... ... ... Petroleum spirit extract ... Sugars (after inversion) . . . Free acid (as citric) . . . ... Phosphoric acid (P,05) . . . ... ... Fruit, 1. _____~ Per Cent. 94.52 0.116 0.50 4.62 0-06 2.51 0.41 0.044 Fruit, 2. Per Cent. 95.13 0.159 0-63 5.50 0.07 3.21 0.48 0.059 Juice, 1. Per Cent. 96.00 0-098 0.50 5.20 2.34 0-60 0.031 - Juice, 2. Per Cent. 96.19 0.088 0.63 6.00 1.96 0.61 0.039 - Juice, 3. Per Cent. 95.48 0.128 0.65 6.40 2-53 0.46 0.025 - The sample of juice No. 3 was obtained from Canadian tomatoes, the other Tartaric, malic, and succinic acids could not be samples being of German origin.detected in any of the samples. w. P. s. Determination of Tale on Rice, Pearl-Barley, etc. R. Kriizan. (zeit. li'ntersuch. Nahr. Genuswz., 1906, xi., 641-650.)-The quantity of talc present as a coating on rice, pearl-barley, or other grain can only be correctly determined by directly weighing the mineral after detaching it from the grains. As the mineral is264 THE ANALYST, readily attacked by hydrochloric acid, especially after ignition, the method proposed by Matthes and Muller (ANALYST, 1905, xxx., 206) is untrustworthy, and methods based on the determination of the magnesia in the ash of the sample (the magnesia being subsequently calculated into talc) give incorrect results, owing to the varying composition of the mineral itself, and to the magnesia natural to the grains.The author, therefore, employs a process in which a weighed portion of the sample is heated with a little hydrogen peroxide and dilute ammonia; bubbles of gas form between the grain and its coating, and completely loosen and remove the latter. The turbid liquid is decanted, the grains are shaken and washed several times with water, and the total liquid then rendered acid with hydrochloric acid, and the organic matter oxidized by the addition of a few grams of chromic acid. The mixture is heated to boiling, filtered, and the residue is washed with water and ignited at the lowest possible temperature. The weight of residue obtained represents the amount of talc in the portion of the sample taken.Besides talc, other minerals, such as mica and certain clays, are used for coating grains. (Cf. '' Facing of Rice," this vol., p. 40.) w. P. s. The. Determination of Alcohol in Chloroform. M. Nicloux. (BUZZ. SOC. Chim., 1906, xxxv., 330-335.)-A small proportion of alcohol is commonly added to chloroform as a preservative. I t can be separated by shaking 5 C.C. of the sample with 20 C.C. of water, which extracts the whole of it, and it can then be determined in the supernatant aqueous layers by the author's bichromate method. Five C.C. of this alcoholic solution (containing not more than 1 part of alcohol in 500) are mixed in a test-tube with 0.1 to 0-2 C.C. of a solution of potassium bichromate (19 grams per litre), and then with pure sulphuric acid (66" B.), which, when added in suEcient quantity (4.5 to 6 c.c.) decolorizes the solution.The liquid is now gradually titrated with the bichromate solution, being shaken and gently heated after every addition, until the colour changes from greenish-blue to a permanent greenish-yellow. The change is most readily recognised in solutions containing less than 0.2 per cent. of alcohol. I t is advisable to make a second determination in which the amount of bichromate used in the first experiment, less 0.1 C.C., is run in at once, the sulphuric acid added, and the liquid boiled for a moment. The contents of the tube ought to remain greenish-blue, whilst in another determination in which 0.1 C.C. more than the first reading is added, the colour should change to greenish- yellow. The number of C.C. consumed, divided by 1,000, gives the amount of absolute alcohol in C.C. per C.C. of solution. When the proportion of alcohol is less than 0.1 per cent. it is best to double the strength of the bichromate solution. Six samples of chloroform examined by this method were found to contain from 1.4 to 10.4 C.C. of absolute alcohol per litre. Test experiments with chloroform containing known quantities of alcohol showed that the results were concordant and accurate. C. A. M.