112 THE ANALYST. ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOODS AND DRUGS ANALYSIS. M. Popp. (Zeit. fiir Untersuch. der Nahr. und Genussmittel, 1904, vii. , 6-12.)-The author has carried out a series of investigations on the reliability of this method (ANALYST, 1898, xxiii., 259), and especially on the influence of variations in the strength of the ammonia used, on the time required for separation of the ether layer to take place, and on the determination of fat in cream by this process, He finds that solutions of ammonia, containing from 4.80 to 24.99 per cent. of NE, may be employed without appreciable The Gottlieb-Rose Method for determining Fat in Milk.THE ANALYST. 113 influence on the results. The ether layer was found to separate completely in one hour. For the purpose of estimating fat in cream, 3 to 5 grammes of the latter are weighed into the cylinder, diluted with water to 10 c.c., and treated:with ammonia, alcohol, and ether, etc., as in the case of milk.After standing one hour the ethereal layer is drawn off as completely as possible ; the solution remaining in the cylinder is once more shaken out with the ether-petroleum spirit mixture, allowed to stand thirty minutes, and the ethereal solution again drawn off. The united extracts are then treated as usual. w. P. 8. The Use of Amy1 Alcohol i n Gterb3r’s Method for determining Fat in Milk. M. Siegfeld. (Zeit. fur. mzgew. Chem., 1903, xvi., 1217-1220.)-The author confirms Van Haarst’s statement (ANALYST, 1903, 213) that some samples of apparently pure amyl alcohol give considerably too high results when used in Gerber’s process.A traction was obtained from a sample of amyl alcohol, which, when used in the above process, yielded 3.9 per cent. of With regard to the nature of this insoluble substance, an ultimate analysis gave results agreeing with formula for amyl alcohol, but the boiling-point was too high for any of the known isomers of the latter. Whether the substance is present in the original amyl alcohol or is formed by the action of the sulphuric acid is still undecided. The best test as to the suitability of any particular sample of amyl alcohol for use in this process is a blank experiment with the same. fat.” w. P. s. On the Use of Phenolphthalin for the Detection of Heated Milk. Utz. (Milch Zeit., 1903, xxxii., 722 ; through Chm.h i t . Rep., xxvii., 328.)zAccording to the author, a mixture of an alkaline solution of phenolphthalin and dilute hydrogen peroxide cannot be used for the detection of boiled milk, as neither boiled nor .unboiled milk gives a colour with the reagent in the cold, whilst the colour produced by warming to 30” or 40’ C. is permanent in-both cases. A. G. L. The Estimation of Methyl Alcohol in Presence of Ethyl Alcohol. T. E. Thorpe and J. Holmes. (Proc. Chem. SOC., xix., 285.)-The method depends on the diflerence in action of a mixture of potassium dichromate and sulphuric acid a n methyl and ethyl alcohols, the evolved carbon dioxide being weighed. The method is applicable to the examination of methylated spirits and medicinal preparations.A. G. L. The Interdependence of the Physical and Chemical Criteria in the Analysis of Butter-fat. T. E. Thorpe. (Journ. Cliem. SOC., 1904, lxxxv., 248-256.)-1n the course of an investigation on the chemical nature of butter produced within the British Isles, which was instituted by the Board of Agriculture for the information of the Departmental Committee on Butter Regulations (this vol., p. 67), a number of butters of known origin, and produced from milk given under varying climatic con-114 THE ANALYST. ditions, were analysed. Of 430 samples received, 357 were examined as regards their Reichert-Wollny number, their specific gravity, saponification equivalent, refractometric number, and, in a certain number of cases, their Hubl-iodine value. A summary of the results obtained is given in the following table : __.~ Number of Samples. 7 17 15 27 37 51 78 56 41 18 10 357 -_ Reichert- Number. Woll11y 22-5 23-5 24.5 25.5 26-5 27.5 28-8 29-5 30.5 31.3 32.6 -_ - ~- Specific Gravity a t 37 *go c. 3- 0.9101 0.9104 0.9108 0.9110 0.9113 0.9114 0.9118 0.9120 0.9123 0-9125 0.9130 -- -- __ ____ 3aponificatior Equivalent. -- 255.4 253.4 251.3 251.1 248.9 247.4 245.7 244-0 242.4 241-5 241.2 , Refracto- Soluble meter Acids." Kumber Per Cent. a t 45" c. 42.0 41.5 41.5 41.3 41-0 40.6 40.1 40.1 on Fat. 4.3 4.5 4.7 4.8 4.9 5.2 5.4 5.6 39.9 , 5.8 39.7 ' 5.7 39.4 6.0 1 I i Insduble Acids. Per Cent. on Fat. 90.1 89.7 89.4 89.3 88.9 88.7 884 88.3 87.9 87.9 87.7 -~ _ _ - Meail Molecular U'eight of Insoluble Acids. 266.9 265.5 265.0 264.2 261-9 261.7 260.9 259.6 260.1 258.0 257.8 -- Twenty samples, with an average Reichert-Wollny number of 24.2, had a mean iodine value of 40.0, whilst thirty other samples, having an average Reichert-Wollny number of 30-8, gave a mean iodine value of 32.4.The interdependence of the main values obtained are shown in a series of curves, and full details of the origin of the samples are published in the Minutes of the Evidence to the Report of the Com- mittee (Cd. 1750, Appendix xxix., 505-588). w. P. s. Determination of Alcohol in Tinctures. T. F. Xarvey. (Chemist and Drzbggist, 1904, xliv., 178.)-The method described consists in diluting the tincture, distilling, and treating the distillate with kieselguhr or kaolin to remove undiwolved oil. The dilution in no case need exceed three times the original volume.To prevent the diluted tincture frothing and bumping during the distillation, a, little paraffin and a few pieces of ignited pipe-clay are added. The kieselguhr or kaolin must be previously washed and dried. If there be any doubt whether a tincture has been sufficiently diluted, further dilution of the distillate will settle the point. About 0.5 gramme of kieselguhr is usually sufficient, and the specific gravity of the treated distillate after filtration is determined. w. P. s. Determinhtion of Starch by Baumert and Bode's Method. H. Witte. (Zeit. fur Untersuch. der Nuhr. und GenussmitteE, 1904, vii., 65-77.) - This method (ANALYST, 1901, xxvi., 20) has been found to give good results with potato starch, * Calculated as bntyric acid.TRE ANALYST.115 'but with wheat-meal and maize flour the figures obtained were always too low. By slightly altering the method, principally as regards time of digestion and final washing of the precipitated starch, the author obtains reliable results with these two flours. I n the case of wheat-flour, the digestion is allowed to proceed for two hours at a pressure of 4 atmospheres. After precipitating with alcohol, as previously described, the residue is washed on to the asbestos filter with a mixture of 25 C.C. of alcohol and 15 C.C. of water, and then successively with mixtures consisting of 25 C.C. alcohol and 15 C.C. water ; 25 C.C. alcohol, 10 C.C. water, and 5 C.C. hydrochloric acid (10 per cent.) ; 25 C.C. alcohol and 15 C.C.water ; then with alcohol, and finally with ether. Maize and rice starches must be digested at a pressure of 4.5 atmospheres. I n the analysis of flours it is pointed out that as the different proteids in flours contain from 16.90 to 18.39 per cent. of nitrogen, an approximation only of the amount of total proteids is obtained by multiplying the nitrogen by a factor. The author, however, found that by using a factor of 6.25, and determining the starch by difference, the percentage of starch agreed closely with that obtained by the above method. As regards the consistently low results given by Dennstedt and Voigtlander's colorimetric method for the determination of starch (ANALYST, 1895, xx., 210), the errors are most likely due to the presence of substances intermediate between starch and dextrin, which substances are insoluble in cold water, and give no blue colour with iodine.w. P. s. The precipitate is dried, weighed and ignited. Characteristics of Olive Oil in which Sardines have been preserved. M. Henseval and M. Deny. (Chenz. Rev. Fett-u. Hum-Ind., 1904, xi., 44-46.)-Sardines were preserved in boxes in the usual manner by sterilization at 110" C . , and the following values show the changes produced by the diffusion of the fish oil into the olive oil, for a year : Specific gravity ... ... Maumend test . . . ... ..- Refractometer reading at 25" C. Acid value ... ... ... Hehner value ... ... ... Reichert value.. . ... ... Iodine value . . . ... ... Unsaponifiable matter, per cent, Saponification value . . . ... Acetyl value .. . ... .-- Glycerin, per cent. ... ... Melting point . . . ... ... Solidification point . . . ... Acid value . . . ... ... Saponification value . . . Iodine value ... ... ... Acetyl value* ... ... ... Fatty Acids. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... Original Olive Oil. 47.3 62.6 5.7 194.9 95.8 0.86 84.9 7.1 10.5 0.95 0-91736 26.7" C. 21.2" c. 200.0 210-57 87-68 10.75 Sardine Oil. 0.9274 96.5 76.5 194.5 6.88 95.10 1 -40 142.0 8.8 10.48 1-36 25-4O c. 27.9' c. 196.3 200.8 147.5 8-4 Olive Oil from the Tin. 0.9186 59.9 65.4 6.8 195.2 94.67 2.00 97-2 7 -08 10.70 0.79 27-08' C. 22.55" C. 201.12 212.24 99-42 10.50 C. A. M. * Lewkowitsch's method.116 THE ANALYST. Cocoanut Oil in Lard. Mecke. (Zeit. f i i r oflentZ. Chem., 1904, x., 8, 9.)-A lard, having an unusually soft consistency, gave on analysis an iodine number of 54.6 and a refractometer number of -2.6.With Halphen’s test a feeble brown coloration was obtained. By shaking the melted lard with alcohol, cooling, filtering, and evaporating the latter, a residue was obtained having an iodine numbar of 39.5, a saponification number of 235, and a refractometer number of - 6-7. From these results the author considers that cocoanut oil wag present in the lard. W. P. S. Detection of Artificial Colouring in Dried Peas. K. Lendrich. (Zed. fiir Untersuch. der Nukr. and Genussnzittel, 1904, vii., 1-5.)-1t is not unusual for dried peas, either in the whole or split condition, to be artificially coloured. The dyed peas are generally treated with talc to give them a polished appearance.The colours employed are greens or orange-yellows, and may be detected by shaking the peas with a mixture of equal parts of alcohol and water and decanting the latter after the lapse of five minutes. With natural peas the solution is colourless or only slightly tinged, whilst with dyed peas an orange-yellow or deep green extract is obtained. The alcoholic solution may then be further teeted as usual by dyeing wool, etc. Talc when present is readily removed from the peas by shaking the peas with water. On decanting the latter and allowing it to stand for a time, the talc settles and may be recognised under the microscope. By treating the ash of the peas with dilute hydro- chloric acid, the talc remains insoluble and may be quantitatively determined.w. .P. s. Searle’s Test for Yeast Extract, H. E. Davies. (Pharm. Jozim., 1904, lxxii., 86, 87.)-The author finds the precipitate formed by boiling yeast extract with the modified Fehling’s solution, previously described in a paper by Searle (Analyst, 1903, 360), may contain considerable quantities of copper oxide, and that even the modified solution itself, on boiling for three minutes, gives a precipitate of copper oxide. He has also, in some cases, obtained precipitates with pure meat extracts. Xearle (ibid.) points out that although meat extracts do sometimes give small precipitates with this test, the appearance of the precipitate is totally different from that yielded by yeast extract. The test is essentially a qualitative one, and depends on the physical characteristics of the precipitate, and not on the weight of the latter.The mixture should not be boiled for more than one minute. With longer boiling copper oxide is thrown down. Although some yeast extracts fail to give quantitative results, others yield approximately constant weights of precipitate. w. P. s. The Determination of the Quantity of Eggs in Pastry. H. Luhrig. (Zeit, f6T Untersuch. der Nahr. und Geimssmittel, 1904, vii., 141-151.)-The most trust- worthy results are obtained by determining the phosphoric acid combined as lecithin and also the ether extract yielded by the sample. The pastry is extracted with ether for twelve hours and then with hot alcohol for a similar time. The phosphoric acid in both extracts is determined in theTHE ANALYST.117 usual way, the sum of the two giving the lecithin-phosphoric acid.” Wheatmeal without eggs gives an average of 0.0229 per cent. of (‘ lecithin-phosphoric acid ” and 1-06 per cent. of ether extract, whilst eggs give an average of 0.320 per cent. and 9-49 per cent. respectively (See also ANALYST, Vol. xxv., p. 100.) w. P. s. Examination of Commercial Peppers. J. W. Gladhill. (Anzer. Journ. Pharna., 1904, lxxvi., 71-81.)-The author has examined typical samples of thirteen different kinds of pepper. In the determination of the piperine 10 grammes of the ground pepper were thoroughly extracted with 95 per cent. alcohol, the extract evaporwted, and the residue mixed with about 100 C.C. of a 10 per cent. solution of potassium hydroxide, and allowed to stand for twenty-four hours with occasional agitation, so as to bring the resins into solution.The undissolved substance was collected on a filter, dissolved in 95 per cent. alcohol, the solution filtered and evaporated, and the crystals weighed as piperine. The oleo-resin was determined by deducting the piperine from the amount of ethereal extract. The following results were obtained : Peppers. Blac k. Singapore (4) . . . ... Tellicherry (4) . . . ... Aleppy (2) ... ... ... Trang (2) ... ... ... . V . , Lienburg (4) . . . ... Lampong (4) . . . ... W.C. Sumatra (2) ... ... Acheen, A (4) ... . I . ,, c (a) ... ... Coriander (4) . . . ... Singapore (3) , . . ... Penang (3) . . . 1 . . ... Decorticated (3) . . . ... White, I Ash. _I Per Cent.3.5 to 4-5 3.8 ,, 4.8 4.7 ,, 4.7 3.8 ,, 3.9 3.6 ,, 4.0 5.0 ,, 5-5 4.0 ,) 4.3 4.0 ,, 4.7 0.8 ,, 1.0 1.0 ,, 1.2 2.1 ,, 2.8 0.8 I , 1.9 Hulls. Eight samples . . . ... ~ 7.0 ,, 9.6 Ethereal Extract. Per Cent. 8.76 to 9.76 7.26 ,, 8-85 9.47 ,, 9.65 8.44 ,, 8.83 8.70 ,, 9.48 8.76 ,, 10.31 9.22 ,, 9.28 9.20 ,, 10.10 7.90 ,, 11-68 8.20 ,, 8.78 6.80 ,, 7.20 6.60 ,, 7.64 5-00 ,, 8.93 Piperine. Per Cent. 6-58 to 7.68 5-91 ,, 6.82 6.75 ,) 7.70 5.12 ,, 5-61 5.98 ,, 6.50 7.00 ,, 8.30 6.68 ,, 7.00 7.10 ,, 7-96 6.81 ,, 9-00 6.78 ,, 7-26 5.74 ,, 6.76 6.25 ,, 7.02 None Oleo-resin. Per Cent. 1.08 to 2.63 0.70 ,, 2.83 1.95 ,, 2.72 3.22 ,, 3.39 2.20 ,, 3.22 1.16 ,, 2.30 2.28 ,, 2.54 2.10 ,, 2.50 1.06 ,, 2.68 1.00 ,, 1.67 0-44 ,, 1.30 0.24 ,, 1.39 5.00 ,, 8.93 The author concludes that the ash should not exceed 6.5 per cent.in the case of black pepper, or 3.0 per cent. for white pepper. He makes a constant allowance of 1 per cent. for sand and other accidental material. Black pepper should yield between 7.5 and 10 per cent. of ethereal extract, and white pepper between 6 and 9 per cent. Only itl the case of coriander pepper did it exceed 9 per cent., but this variety is never ground for white pepper on account of its cost. The piperine should range from 5.5 to 9 per cent, in good black pepper, and the author takes the former118 THE ANALYST. figure as a minimum standard. only adulterants used to any considerable extent. He states that at the present time the hulls are the C. A. M. The Determinat.ion of Citric Acid by Means of Lime. 0.v. Spindler. (Chem. Zeit., xxvii., 1263.)-The author has investigated Klinger and Bujard's method (Zeits. angew. Chem., 1891, 514), in which the citric acid is weighed as calcium citrate, Ca, (C,H,(OH)(COO),), + 4H,O, and shows that the method is utterly unreliable, as the salt is very appreciably soluble in water, even in the presence of ammonium chloride. He also shows that the salt slowly loses water even at 100" C., and that it contains more than the theoretical amount of calcium if it has been obtained by the direct neutralization of citric acid with lime. A. G. L. A New Modification of Denighs' Reaction : The Detection of Tartaric Acid in Citric Acid. 0. v. Spindler. (Chem. h i t . , xxviii., 15.)-The author modifies Denigds' test for citric acid by using a 0.5 per cent.solution of potassium bichromate instead of the 2 per cent. potassium permanganate solution. The test is carried out by dissolving 0.5 gramme of the acid to be examined in 10 C.C. of water, adding 2 C.C. of mercuric sulphate solution (obtained by dissolving 5 grammes mercuric oxide in.20 C.C. sulphuric acid and 80 C.C. water), heating to boiling, and adding 2 C.C. of the bichromate solution. The liquid is then allowed to stand. Citric acid alone produces only a yellow precipitate containing chromium and mercury; tartaric acid, on the other hand, reduces the bichromate with production of the usual green colour. With 5 per cent. of tartaric acid the reaction is quite sharp, the colour beginning to change at the end of five minutes. A. G. L. A Suggested Test for Free Salicylic Acid in Bismuth Salicylate.W. Lyon. (Pharm. J o z ~ ~ n . , 1904, lxxii., 219.)-The official test for this impurity being unreliable, since the alcohol exerts a decomposing action upon the bismuth salicylate, a reaction being obtained with ferric chloride similar to that indicating the presence of free salicylic acid, though none was present in the sample, the author suggests the sub- stitution of benzene for. the alcohol. A small quantity of the salt is placed on a filter, benzene is poured on it, and the filtrate collected on the surface of a dilute solution of ferric chloride contained in a test-tube. Should free salicylic, acid be present, a violet ring appears at the junction of the two liquids. w. P. s. Colour Reactions of Pilocarpine. E.Barral. (Joztm. Pharm. Chim., 1904, xix., 188, 189.)-The most characteristic reaction of pilocarpine is the violet colora- tion (colouring matter soluble in benzene) obtained on adding a few drops of potassium bichromate solution, followed by a, few drops of hydrogen peroxide solution, to the pilocarpine solution. Sodium persubhate heated with 1 or 2 C.C. of a dilute solution of pilocarpine gives a yellow coloration, and emits vapours with a slightlyTHE ANALYST. 119 ammoniacal odour. These vapours turn turmeric paper blue, and blacken mercurous nitrate. Szdphuric acid with formalin, when heated with a few drops of a, pilo- carpine solution, gives a yellow coloration changing to yellowish-brown, then to blood red, and finally to brownish-red. Mandelin’s reagent, heated with a very dilute solution of pilocarpine, gives a golden yellow coloration gradually changing to bright green, and finally to bright blue. Potassium permangunate in a 1 per cent.solution in strong sulphuric acid, when heated with a solution of pilocarpine, is at first decolorized, and then becomes dark yellow, and gives off vapours with an odour exactly like that of tartaric acid decomposed by heat. C. A. M. New Reactions of Acetanilide. E. Barral. (Joum Pharm. Chim., 1904, xix., 237.)-The phosphomolybdic reagent for phosphates added to a solution of acetanilide gives a bright yellow precipitate. This is soluble on heating, and can thus be distinguished from the similar precipitate given by phenacetin. M a d e l i d s reagent added to a solution of acetanilide gives a red coloration changing rapidly to brownish- green, whereas with phenacetin an olive-green coloration is obtained, changing to reddish-brown on heating. C. A. M. New Colour Reactions of Phenacetin. E. Barral. (Journ. Pharm. Chim., 1904, xix., 237, 238.)-In addition to the reactions mentioned above (preceding abstract) the following are described : Sodizm perszclphate heated with a solution of phenscetin gives a yellow coloration, becoming orange after prolonged boiling. Bromine water heated with a few crystals of phenacetin turns them rose-coloured, whilst the liquid itself becomes orange-yellow. On cooling, a brown precipitate is gradually deposited. Millon’s reagent heated with phenacetin gives a yellow colora- tion changing to red. Nitrous ether is then liberated and a yellow precipitate formed. C. A. M.