274 THE ANALYST. ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOODS AND DRUGS ANALYSIS. Note on the Periodide Test for Alkaloids. A. H. Clark. (Anzcr. JO26YlZ. Pharm., 1909, 81, 176-177).-The author has observed that water saturated with ether gives on acidification a reddish-brown precipitate of kdinc on adding a solution of iodine in aqueous potassium iodide, and this precipitate resembles in appearance that formed by an alkaloid with the same reagent. Water containing ether without acidification does not cause such a precipitate, n9r does acidulated water, nor acid alone, with the iodine reagent. I n order to guard against this source of error in testing for traces of alkaloids in extraction work, it is only necessary to add an equal volume of water, when the precipitate of iodine will dissolve, while that due to an alkaloidal iodide will be unaffected.A. R. T. The Distillation of Butter-Fat, Cocoanut Oil, and their Fatty Acids. By K. S. Caldwell and W. H. Hurtley. (Proc. Chem. Soc., 1909, 25, 73.)-The authors are of opinion that fats and fatty acids have no boiling-points in the vacuum of the cathode light, but that for any particular substance a temperature can be selected at which evaporation occurs at a speed convenient for fractional distillation. Butter-fat, cocoanut oil, and their fatty acida were distilled in the vacuum ofTHE ANALYST. 275 the cathode light. The lowest fraction obtained from butter-fat distilled with the bath temperature at 250" to 270' C. and inner thermometer at 187" to 210' C. Tributyrin distils rapidly with the bath temperature at 127" and inner thermometer at 107' C. For this and other reasons it is concluded that butter does not contain tributyrin. The iodine numbers yielded by the various fractions seem to indicate that there is little or no triolein in butter-fat.Lauric acid forms at least 60 per cent. of the fatty acids in cocoanut oil, whilst it could not be detected in butter. This method of distillation enabled the authors to detect with ease the presence of 10 per cent. of cocoanut oil in butter. The presence of palmitic acid in cocoanut oil has been questioned by Ulzer (Chenz. Revue, 1899, 203), but the authors isolated several grams of this acid from cocoanut oil. Estimation of Quinine in Quinine Tannate and Ferro-Citrate. E. Rupp and W.Callies. (Apoth. Zeit., 1909, 24, 159; Pharnz. Jozwn., 1909, 82, 584.)-1.2 grams of quinine tannate is thoroughly shaken with 10 grams of a solution of potassium carbonate of 1.334 specific gravity until a uniform mixture results, when exactly 30 grams of ether are added, and the whole well shaken for some minutes. Half a gram of tragacanth is next added, the shaking repeated, and the mixture set aside for five minutes. Exactly 25.3 grams of the clear ethereal layer (= 1 gram of the tannate) is removed, the ether evaporated, and the residual quinine, which should not be less than 0.3 grams, weighed. Similarly, 1.2 grams of quinine ferro- citrate is dissolved in 5 grams of water, the alkaloid liberated with 5 grams of caustic soda solution, 0.5 gram of tragacanth added, and the whole shaken with 31 grams of ether, and 25.1 grams of the ethereal solution evaporated.A. R. T. Composition of Infant and Invalid Foods. (The Connecticut Agric. Exp. Stat. Report, 1908, Part 9, 599-606.)-This paper contains a number of analyses of proprietary foods. The Estimation of Certain Organic Acids occurring in Fruits. G. Jorgensen. (Zeit. Untersuch. Nahr. Genussnz., 1909, 17, 396-412.)-As the result of further experimental work, the author suggests certain modifications in the process described previously for the separation and estimation of certain organic acids (ANALYST, 1907, 32, 169). The residue of succinic acid obtained should be re-dissolved in 9 C.C. of water, the solution acidified with 1 C.C. of dilute hydrochloric acid, and again shaken out five times with ether; the ethereal solution is then evaporated, and the quantity of succinic acid estimated as described.The strength of the alcohol. employed for the separation of the barium citrate from the barium malate should be 26 per cent. by volume; in cases where the precipitate of barium citrate is large, the precipitation must be repeated in order to separate all the barium malat e. A sample of sloe fruit (Przmus cornmzmis) examined contained about 3 per cent, of malic acid and a very small quantity of another acid, which was possibly succinic acid ; tartaric and citric acids could not be detected in the fruit, w. P. s.276 THE ANALYST, The Chemical Examination of Isinglass. K. Dieterich. (Clzem. Zeit., 1909, 33, 357-358; 367-368.)-The following method of analysis has been devised by the author, the material in each case being first cut into fragments of 0.5 square em.in size.--Moistzwe: About 5 grams are dried at 100" to 105" C. Ash and potcissium carbonate in the ash are estimated in the usual way. Substances soluble in boililzg water: Ten grams are mixed with about 500 C.C. of cold water in an enamelled vessel, which is allowed to stand on a water-bath until most of the isinglass rises to the surface. The liquid is then boiled over a naked flame until violent frothing has ceased, after which it is evaporated to 300 or 400 c.c., any adherent particles being meanwhile detached from the sides of the vessel with a glass rod. The vessel is again transferred to a water-bath, and as soon as the insoluble matter has settled, the supernatant liquid is decanted as completely as possible into a graduated litre flask.The residue is treated with 800 C.C. of boiling water, and the liquid evaporated over a free flame to 200 c.c., and decanted as before. This process is repeated three or four times until the flask is nearly filled, and finally the residue itself is washed into the flask. The contents of the latter are cooled to 15" C., made up to the mark, and filtered, 50 to 100 C.C. of the opalescent filtrate evaporated, and the residue dried at 100" to 105" C. Absorption value and gelatinising power (Quellungs- xahl) : Ten grams of the sample are mixed with 800 grams of hot water in a tared enamelled vessel, and the liquid evaporated on the water-bath with constant stirring to about 510 grams.If no gelatinisation takes place on cooling, another 50 to 100 C.C. of water are evaporated, and the liquid again cooled. The weight at which gelatinisation occurs gives the required values. Thus, e.g., if the weight was 370 grams, the gelatinising power is 1 : 36, or the absorption value is 36. Fat: Ten grams are extracted for three hours with ether in a Soxhlet apparatus. Collagene is taken as the difference between the fat and soluble plus insoluble substances. Crude glutin : Ths dry residue from the estimation of the fat is completely exhausted with boiling water in the manner described above, and 500 C.C. of the filtrate (= 5 grams of the fat-free isinglass) evaporated to about 50 grams i n a tared beaker, and treated, little by little, while still hot, with 200 to 300 C.C.of absolute alcohol. The precipitate is allowed to subside for at least twelve hours, and the supernatant liquid decanted through a small tared filter which is washed with alcohol. The weight of the residue in the filter and beaker, dried at 100" C., gives the amount of glutin. Acid value: This is determined by heating 2 grams of the isinglass for three hours on the water-bath, with 100 to 150 C.C. of water, filtering the solution, and titrating an aliquot portion of the filtrate. Iodine watue: Fifty C.C. of the aqueous filtrate (=0*5 gram of isinglass) are shaken with 20 C.C. of a -& potassium iodide solution of iodine, and the unabsorbed iodine titrated with sodium thiosulphate after standing for twenty-four hours.Szilphur : The isinglass is fused with potassium nitrate and sodium carbonate, and the aqueous solution of the residue tested for sulphuric acid. This test is of importance, since isinglass bleached with sulphurous acid is of less value than products not artificially bleached. Starch is also tested for in the aqueous solution. Optical rotation of the gZutiiz solution; The aqueous solution of the glutin should be levo-rotatory. The Artificial products may give a positive reaction.THE ANALYST. 277 following results were thus obtained in the analysis of twenty samples of genuine isinglass, and of a Russian sample adulterated with gelatin : Moisture ... ... Ash ... ... Potassium carbon- ate in ash ... Soluble substances I n s o l u b l e s u b - stances... ... Absorption value.. . Fat Collagene. . . ... Crude glutin ... Acid value ... Iodine value . . . Ash in glutin ... Optical rotation of ... ... glutin ... ... Sulphur . . . ... Price, per kilo. ... Russian Saliansky , Beluga, Samovy). Per Cent. 13-20 0.5-1-7 8-3 3 65-81 1-19 0-49 0-1-1.2 79-85 66-82 0-6.0 19-45 0.4-0-7 laevo-rotatory present 4-18 marks Chinese. Per Cent, 11-17 0.9-2.3 32-53 68-86 2-15 14-25 0.1-1*2 81-88 69-74 0 39-46 0.67 Iwo-rotatory present 2-11 marks American (Brazilian, Vene- zuela, Maracaibo, and refuse). Per Cent. 13-18 1-3.7 6-37 59-75 9-25 16-55 0.1-0.8 80-87 66-75 0-2.76 30-47 0-4-0.7 lmo-rotatory present 1-4.50 marks Saliansky adulterated with Gelatin. Per Cent. 16 0.6 72 a2 1.5 0.3 25 83 82 37 3.8 0.4-0.7 laevo-ro t story present - A good sample should contain as little ash as possible, and a high percentage of soluble substances and collagene, whilst the latter should contain a large amount of glutin, though approximate agreement between the values for collagene and glutin does not occur in genuine products.The presence of gelatin is indicated by the ratio between these two substances, by the proportion of potassium carbonate in the ash, and by the absorption and acid values. Thus, a sample of Saliansky isinglass contained 0.358 per cent. of potassium carbonate; a sample of gelatin, 0.695 per cent. ; and a sample of isinglass adulterated with gelatin, 0.422 per cent. A high acid value in pure isinglass indicates decomposition, and good samples are practically neutral. Gelatin has an acid value of over 11, and the adulterated sample in the above table therefore has an acid value of nearly 4.C. A. M. The Composition of Kirsch Liqueurs. X. Rocques and L. Levy. ( A m . de Chim AiznZ. Appl., 1909, 14, 138-140.)-Comparative distillations were made with a solution of hydrocyanic acid in 50 per cent. alcohol, and with samples of new and old Kirsch liqueurs both before and after saponification with sodium hydroxide. In each case nine fractions of 100 C.C. each were collected, and the hydrocyanic acid in them titrated with standard silver nitrate solution in the presence of ammonia, and potassium iodide. The saponified samples were rendered slightly acid with phosphoric acid before distillation. The amounts of hydrocyanic acid formed by direct distillation corresponded to 3.5995 and 22.0 C.C.of silver nitrate solution278 THE ANALYST. respectively in the case of two recently prepared samples, and ranged from 8.45 to 17.25 c,c. in the case of five samples two or three years old. After saponification the two recent samples gave distillates requiring 17-45 and 19.85 C.C. respectively, and the other samples distillates requiring from 6.75 to 17.50 c.c., the greatest increase being 2-75 C.C. I n the distillation of the alcoholic solution of hydrocyanic acid the whole of that acid passed over in the first five fractions, the curve being a continuous one. The curve for the amounts of hydrocyanic acid in the different fractions distilled from recently prepared Kirsch liqueurs differed from that of the hydrocyanic acid solution and from that of old liqueurs.In the latter it fell as far as the fifth fraction, then rose to a maximum in the seventh fraction, to fall again to the ninth fraction. After saponification the curve approximated that of a hydrocyanic acid solution. The last fractions of the distillation, corresponding to the maxima of the curves, had a characteristic odour, resembling that of linseed-meal warmed with water. This odour was not perceptible after saponification, but the distillates at the corresponding points then contained fatty matter. From these results the authors conclude that only part of the hydrocyanic acid in Kirsch liqueurs two or three years old is in the free state, and that a considerable proportion of that acid is in combina- tion with fatty substances. C .A. M. Estimation of Malic Acid in Wine. C. von der Heide and H. Sieiner. (Zed. Uiztersuclz. Nahr. G ~ I Z U S S ~ . , 1909, 17, 307-315.)-The various steps involved in the method proposed are : (1) Removal of the tartaric acid as potassium hydrogen tartrate; (2) removal of the acetic and lactic acids as their alcohol-soluble barium salts; (3) extraction of the succinic and malic acids by means of ether; and (4) estimation of the malic and succinic acids from the alkalinity of the ash of their alkali salts. Fifty C.C. of wine are treated with 1 C.C. of glacial acetic acid, 0.25 C.C. of 20 per cent. potassium acetate solution, 7.5 grams of powdered potassium chloride, and 7.5 C.C. of 95 per cent. alcohol. After the lapse of fifteen hours the precipitate is collected on a filter, washed with a mixture consisting of 15 grams of potassium chloride, 20 C.C.of 95 per cent. alcohol, and 100 C.C. of water, not more than 10 c.c of the solution being used for the washing. Ths filtrate and washings are evaporated to a volume of a few c.c., the residue is dissolved in a little water, and the solution neutralised with powdered barium hydroxide after theaddition of 5 C.C. of 10 per cent. barium chloride solution. The excess of barium hydroxide added is removed by treatment with carbon dioxide, the whole solution is brought to a volume of exactly 20 c.c., and 85 C.C. of 96 per cent. alcohol are added with constant stirring. At the end of two hours the precipitate is collected on a filter, washed with 80 per cent.alcohol, then rinsed with water back again into the basin and evaporated almost to dryness. The residue is treated with 3 C.C. of 40 per cent. sulphuric acid, and suflicient powdered anhydrous sodium sulphate is added to form the whole into a dry mass. This is extracted with ether in a Soxhlet apparatus for six hours, the ethereal extract is diluted with a little water, and, after the ether has been evaporated, the solution is treated with 3 grams of animal charcoal, the mixture being placed on the water-bath for one hour. The charcoal is now removed by filtration, washed with hot water, and the filtrate, thus freed from tannin is neutralised, evaporated toTHE ANALYST. 279 dryness, the residue is carefully ignited, and the alkalinity of the ash is titrated.From the alkalinity (carbonate) found, the amounts of succinic acid and rnalic acid present may be calculated; or the succinic acid may be estimated separately by the process described in the following abstract and the amount found deducted from the sum of the two acids. Results of experiments are given which show that from 96.3 to 100.6 per cent. of the quantities of malic acid added to wine (about 0.3 gram of the acid to 100 C.C. of wine) may be found by the method. w. P. s. Estimation of Succinie Acid in Wine. C. von der Heide and H. Steiner. @it. Untersmh. Nalw. Genussm., 1909, 17, 291-307.)-The authors have subjected the method described by Kunz (ANALYST, 1903, 28, 314) to a critical examination, and find that, whilst the process as a whole is the best of many methods which have been proposed for the estimation of succinic acid, certain modifications in the method of procedure are necessary to obtain accurate results.The process as modified is as follows : Fifty C.C. of the wine are evaporated in a basin of about 200 C.C. capacity until the alcohol has been removed; after the addition of 1 C.C. of 10 per cent. barium chloride solution and a little phenolphthalein, the residual solution is treated with powdered barium hydroxide until all the acidity has been neutralised. Excess of barium hydroxide is removed by treating the mixture with carbon dioxide, and 85 C.C. of 96 per cent. alcohol are then added to the mixture, with constant stirring. After the lapse of at least two hours, the precipitate consisting of barium succinate, tartrate, and malate, together with other barium salts, is collected on a filter, washed with a small quantity of 80 per cent.alcohol, and then washed back again into the basin by the aid of a jet of boiling water. The contents of the basin are now heated until all alcohol has been removed, and 5 per cent. potassium permanganate solution is then added in quantities of about 3 C.C. at a time until the red coloration does not disappear after the mixture has stood for five minutes. A further 5 C.C. of permanganate solution are then added, and the mixture is heated on the water-bath for fifteen minutes. The excess of permanganate is destroyed by the addition of sulphurous acid, and, after the mixture has been acidified with sulphuric acid, more sulphurous acid is added until all the manganese dioxide has been redissolved.The mixture is then evaporated to a volume of about 30 c.c., and extracted with ether for twelve hours in a percolating apparatus, after the addition of so much 40 per cent. sulphuric acid that the solution contains about 10 per cent. of free sulphuric acid. The ethereal extract is diluted with water, the ether is evaporated, and the residual solution, after neutralisation, is transferred to a 100 C.C. flask, 20 C.C. of & silver nitrate solution are added, and the whole is diluted to the mark and filtered. The excess of silver is then titrated in 50 C.C. of the filtrate, Volhard's method being used for the purpose. Data are given showing that the method is trustworthy. w. P. s. A Method of Estimating the Volatile Acids in Wine. P. Malvezin. (Bull. Xoc. Chim., 1909 [iv.], 5, 332-335.)-The following rapid method is based on the author's observations that 72 per cent. of the volatile acids in wines are dissolved by ether, whilst tartaric acid is insoluble and succinic acid only sparingly soluble280 THE ANALYST. under the conditions of the estimation. Ten C.C. of the wine and 10 C.C. of ether are shaken vigorously together for one or two minutes in a tube 20 cm. in length by 20 mm. in internal diameter. The tube is now closed by a cork through which passes a, thermometer, and is allowed to stand for ten minutes in a water-bath at 15’ C . Five C.C. of the supernatant ether are then drawn off with a pipette, and mixed with 5 C.C. of 90 per cent. alcohol, and the liquid titrated with & sodium hydroxide solution, with phenoJphthalein as indicator. The volatile acidity in parts per 1,000 of sulphuric acid is found by means of the following formula in which A represents the number of C.C. of alkali used- (2A - 0.2) x 25 x 1-63 ti The results thus obtained with twenty samples of wine of different kinds and origin were almost identical with those given by DUCI&UX’S method. C . A. M.