476 THE ANALYST, ORGANIC ANALYSIS. Detection of Certain Animal Fats in admixture with Other Animal Fats. E. Polenske. (Arbeit. Kaiserl. Geswadlieitsarnte, 1908, 29, 272-275.) -Referring to the method described previously (ANALYST, 1907, 32, 382), the author states that the melting-point of the fat is more readily observed if a comparison capillary tube, filled with a clear oil, be fixed in the field of observation, and that, in determining the solidifying-point, about 1 C.C. of concentrated sulphurio acid should be introduced into the air-jacket surrounding the test-tube, in order to remove traces of moisture which may condense on the sides of the tube. Further determinations confirm the '' difference value" given previously (Zoc. cit.) for lard. In the case of goose-fat, values were obtained varying from 14.7 to 16-7.Butter should not be considered as adulterated with lard or other fat even when the sample gives a, higher value than that recorded for pure butters, if a mixture consisting of 75 parts of the sample and 25 parts of beef-fat yields a higher value than 15, and if at the same time the original butter yields a value below that given by the mixture. w. P. s. Natural and Artifleial Asphalt. J. Marcusson and E. Eiekmann. (Chenz. Zeit., 1'308, 32, 965-967.)-The presence of coal-tar pitch in asphalt may be detectedTHE ANALYST. 477 by its characteristic odour, by its content of free carbon (up to 21 per cent.), by the anthraquinone reaction, and by the behaviour of the products of distillation towards alcohol and concentrated sulphuric acid.Graefe’s diazobenzene chloride test (ANALYST, 1907, 31, 204) indicates, contrary to Graefe’s statements, either pitch from ordinary coal-tar or from brown coal-tar. Pitch from fats is recognised by the smell of acrolein obtained on heating, by the high acid content of the first distillates, and by the acid and saponification values of the alcohol-ether extracts. If the above are absent, mineral oil pitch may be looked for as follows : 50 grams of the sample are dissolved in 75 C.C. of benzene, the solution is poured into 1 litre of petroleum ether, and the filtered liquid treated three times with 75 C.C. at a time of concentrated sulphuric acid to remove resinous bodies. The liquid, filtered if necessary, is washed with water, then with alcoholic potassium hydroxide, and finally again with water.The petroleum ether is then distilled off, the residue heated for ten minutes at 105’ C., and weighed. Petroleum pitch is probably present if the oil obtained in this manner exceeds 30 per cent., reckoned on the ash-free asphalt, and if it does not “flow ” after standing for one hour s t 20” C., being, instead, pasty, and showing Vaseline-like particles. As a further test, the oil is distilled, and the distillate tested for paraffin wax by solution in alcohol-ether and cooling to - 20” C. If the oily residue contains more than 2 per cent. of paraffin, petroleum pitch is present. The test is useful only if at least 30 per cent. of petroleum pitch has been added. Artificial sulphurisation of asphalt or pitch can be detected by passing steam through the sample.Natural asphalt does not evolve more than a trace of sulphu- retted hydrogen under this treatment, whilst artificially sulphurised pitches evolve considerable quantities. A. G. L. The Diazo Reaction of Atoxyl. E. Covelli. (Chem. Zeit., 1908, 32, 1006.) -Solutions of atoxyl (sodium anilarsenate) give (1) a yellow precipitate or coloration with calciuni hypochlorite ; (2) a blue coloration with calcium hypochlorite in t.he presence of phenol and ammonia, perceptible in a liquid containing only 1 part in 100,000; (3) a yellow precipitate with reducing agents in the cold; and (4) a yellow coloration when heated with an aldehyde of the fatty series and with a mineral acid. More sensitive and characteristic than any of these reactions are those given by the arsendiazobenzol formed on treating a solution of ntosyl with a.O.5 per cent.solution of sodium nitrite and a few drops of strong sulphuric acid: ( a ) With a-naphtliylarnine hydrochloride a purple coloration is obtained. This reaction is extraordinarily sensitive, and may be used for tho detection of traces of atoxyl in urine without previous decolorisation. Thus, mine containing 0.01 gram of atoxyl gives, when treated with the reagent, a yellow colour., changing to orange, and then, after about an hour, to a purple-red, which reaches its maximum intensity in about two hours, and then slowly fades. The presence of urea or of other amino com- pounds which react with nitrous acid does not interfere with the test. Since the intensity of the coloration is proportional, under parallel conditions, to the concen- tration of the atoxyl, the reaction may also be made the basis of a, colorimetric method of estimation. ( h ) On treating the arsendiazobenzol solution with a drop of acetaldehyde, followed by a few drops of potsssiuni hydroxide solution, a carmine-red478 THE ANALYST.coloration is produced, which gradually fades, giving place to a yellow coloration The addition of a sufficient amount of the alkali solution prevents the carmine colour from fading. (c) A purple-red coloration is obtained on treating the liquid with P-naphthol, abrastol, resorcinol, morphine, dionine, or phenols, and then with potassium hydroxide. ( d ) Srsendiazobenzol behaves like sulphodiazobenzol when present in certain pathological urines which give Ehrlich's diazo reaction.(See also ANALYST, 1903, 28, 113 ; 1907, 32, 325.) C. A. M. The Products obtained on the Hydrolysis of Casein. Z. H. Skraup. (Monatsh. Chenz., 1908, 29, 791-798.)-Amongst the substances formed when casein is hydrolysed by means of acids are found three compounds having the s&me composition as leucyl-valyl anhydride. One of these is strongly laevo-rotatory, the second is slightly optically active, and the third is inactive. Diketopiperazine is also formed, probably from the amino esters of leucine and valine. Compounds having the composition of diketopiperazine are found in the Substances remaining after distilling the volatile portion of these esters under reduced pressure. Leucine, valine, and amines having the composition of butylamine and amylaminecare also present.w. P. s. Estimation of Colophony in Shellac. C. Ahrens. (Chenz. Zeit., 1908, 32, 996.)--For the detection and approximate estimation of colophony in shellac reliance is usually placed upon the iodine value, and the calculations based upon the recorded values of 10 for shellac and 125 for colophony. The author finds, however, that the iodine value of colophony shows great variations, according to the quality of the product, and may range from 110 to 164. Moreover, the absorption of iodine is incomplete after the ordinary time of interaction (six hours), but appears to be practically complete after thirty hours. These facts must be taken into account in any calculation of the proportion of colophony from the iodine value of a mixture. C.A. M. A Colour Reaction of Oleie Acid and its Use in Distinguishing Vegetable from Animal Fibres. A. Manea. (BzLZZ. SOC. de Stiinte, Bucharest, 1908, 17, 256- 257.)-When a substance such as cellulose, starch, celluloid, dextrin, or a sugar, is dissolved in strong sulphuric acid, and the solution treated with EL few drops of oleic acid or of an oil containing oleic acid, and then with water, added drop by drop with constant shaking, there is produced an intense red coloration, which changes to violet on the further addition of water. If the latter be added without shaking, a, very characteristic coloured ring is obtained. Animal fibres do not give this colora- tion, and the test therefore af'fords a rapid means of distinguishing between, e.g., true and artificial silks.If the fibres have been sized it is necessary to boil them with water, and to dry them again before applying the test. The presence of dyestuff's does not affect the production of the coloration. Certain fractions of crude petroleum, especially those distilling about 250" C., give the same colorations as oleic acid in this reaction. C. A . If.THE ANALYST. 479 A Spectrum Reaction of Oleic Acid. J. Lifschutz. (Zeitsch. physiol. Chem., 1908, 56, 446-452.)-When oleic acid is oxidised by means of chromic acid in acetic acid solution, and the mixture then treated with sulphuric acid, a solution is obtained which has a characteristic absorption spectrum. The latter shows a broad band in the green portion close to the blue, a narrower band near the yellow, and a narrow line between the orange and yellow.The test is best carried out by dissolving 1 drop of oleic acid in 4 C.C. of glacial acetic acid, adding 1 drop of glacial acetic acid containing 10 per cent. of chromic acid, and then 10 or 12 drops of con- centrated sulphuric acid. The green colour of the solution soon changes to violet or red, and the spectrum is then observed. If the coloration is too deep to allow the observation to be made, the solution may be diluted with glacial acetic acid. The test is useful for detecting the presence of traces of oleic acid in stearic or palmitic acids, etc. The test may be rendered more sensitive by heating the mixture, after the addition of the sulphuric acid, to a temperature of 70" to 80" C., and then adding chloroform until the mixture becomes lukewarm and turbid.When quite cold the mixture separates into two portions, the lower of which contains the substance giving the spectrum. The intensity of the coloration and of the spectrum is pro- portional to the amount of oleic acid present. w. p. s. Estimation of Phenol. W. A. Puckner and A. H. Clark. (Amer. Journ. Pharm., 1908, 80, 484-486.)-For the estimation of phenol in pharmaceutical products, the substance is covered with water in a round-bottomed distilling flask and connected with a steam generator and a Liebig's condenser. A current of carbon dioxide is passed through the whole apparatus for at least fifteen minutes, \\.hen steam is conducted through the material and the distillation continued until 250 C.C.of distillate have been collected, a brisk current of carbon dioxide passing during the whole of the operation. Simple saturation with carbon dioxide previously to steam-distillation only liberates about 89 per cent. of the phenol present, while about 96 to 98 per cent. of the phenol distils in the first 100 C.C. of distillate if the operation be conducted as described above. An aliquot portion of the distillate (not exceeding 50 c.c.) is then titrated with standard bromine for the volumetric estima- tion of phenol, as directed in the United States Pharmacopaia. The method is applicable even in the presence of considerable quantities of potassium hydroxide, while sulphites, bromates, and nitrates do not interfere.A. d. T. Estimation of Salicylates. A. Seidell. (Chem. Zeit., 1908, 32, 1009.)- The method is based upon the fact that on treating a solution of salicylic acid in concentrated hydrochloric acid with bromine, dibromsalicylic acid (melting-point, 220' C.) is obtained, and that at 80" to 90" C., and in the presence of a relatively small amount of water, the reaction is quantitative. From 2 to 3 grams of the salicylate are dissolved in 100 C.C. of water, and from 3 to 5 C.C. of the solution treated in a stoppered flask with from ten to twenty times the volume of concentrated hydrochloric acid, and then with N/5-potassium bromate solution, which is added, little by little, until the liquid assumes a permanenh faint yellow tint. The flask is then warmed and shaken until the yellow colour disappears, after which more480 THE ANALYST.bromate is added, and the shaking and heating repeated. This treatment is continued until the temperature has reached 80" or 90' C., and the colour produced by the addition of 2 or 3 drops of the bromate solution persists for at least fifteen minutes. Each molecule of the salicylic acid will then have absorbed four atoms of bromine. C. A. M. Colour Reactions of Sesame Oil and Bile Acids with Various Sugars. C. Fleig. (BUZZ. SOC. Chim., 1908, 3, 99%999.)-Experiments were carried out in order to ascertain which sugars give the most sensitive reaction in the usual Baudouin test for sesame oil. I t was found that practically only three sugara- namely, laevulose, sucrose, and invert sugar-can be used ; other carbohydrates, such as rafinose, xylose, erabinose, galactose, mannose, dextrose, lactose, maltose, etc., yield but slight, if any, coloration (cf.ANALYST, 1904, 29, 290). I n the case of Pettenkofer's test for bile acids, the three sugars which were found to give the best reaction in the Baudouin test also gave the most intense colorations with bile acids ; the other sugars yielded fainter colorations, and the reaction took place more slowly. IT. P. s. Colour Reactions of Sesame Oil with Aromatic Aldehydes. C. Fleig. (BziZZ. SOC. Chinz., 1908, 3, 984-991.)-The furfural in the reagent recommended by Villavecchia and Fabris (ANALYST, 1894, 19, 47) for the detection of sesame oil, may be replaced by other aromatic aldehydes. Of the latter, p-hydrosybenzaldehyde, y-methoxybenzaldehyde, protocatechuic aldehyde, vanillin, piperonsldehyde, and cinnamaldehyde act equally as well as furfural ; then follow salicylaldehyde, benzaldehyde, o-nitrobenzaldehyde, and p-dirnethylaminobenzaldehyde.The least sensitive are 716-nitrobenzaldehyde, cuminaldehyde, and p-nitrobenzaldehyde. The substance in the oil which gives the coloration may be extracted from the oil by means of absolute alcohol, and the alcoholic solution then used for the test, w. P. s. Volumetric Estimation of Lactose by Means of Ammoniacal Copper Solution. Y. Shimidzu. (Bioclicm. Xeitsch., 1908, 13, 243-361.)-\Vhilst lactose cannot be accurately estimated by any of the volumetric methods when the sugar is titrated directly, the estimation becomes quite trustworthy if the migar is inverted previously. Using the modified Pavy's solution recommended by Kumsgawa and Suto, 0.0109 gram of lactose (after inversion) bas the same reducing power as 0.01 gram of dextrose.Lactose is completely inverted by heating from 0.25 t o I grani of the sugar with 100 C.C. of 10 per cent. sulphuric acid, or 5 per cent. hydrochloric acid, for one hour at a temperature of 100" C. The d-dextrose and d-galactose produced remain unchanged if the heating be continued for a further thirty minutes. The results obtained agree with those yielded by the gravimetric process for the estimation of lactose. w. P. s. Detection of L%vu!ose in the Presence of Other Carbohydrates. (BUZZ. SOC. Ckim., 1908, 3, 966-984.)-The tests proposed are based J. Pieraerts.THE ANALYST.48 1 on the fact that lizvulose reduces alkaline copper solutions much more readily than does any other sugar which occurs naturally. Whilst Fehling's solution cannot be used for differentiating the various reducing sugars, a modified Ost solution (250 grams of potassium carbonate, 100 grams of potassium hydrogen carbonate, and 1 7 5 grams of crystallised copper sulphate per litre) was found to answer the purpose. Levulose reduces this reagent in two and a half hours at the ordinary temperature, or in one hour at 35" C. ; other sugars are without action, but the pentoses show a reducing action after about four hours at the ordinary temperature, or in one hour at 35" C. A solution containing 12 grams of glycocoll, 6 grams of cupric hydroxide, and 50 grams of potassium carbonate per litre is also a very useful reagent for detecting lmulose ; it is reduced by a 5 per cent.solution of lmwlose in four hours at the ordinary temperature, but other sugars, including the pentoses, have no action. Lmulose may be detected in honey, fruits, sweets, marmalade, crude sugars, molasses, etc., by means of the above reagents. The solution used for the test should contain about 5 per cent. of total reducing sugar, of which about 20 per cent, should be levulose. w. P. s. Polarimetric Estimation of Starch. E. Ewers. (Chem. Zeit., 1908, 32, 996-997.)-For the valuation of raw materials for the manufacture of starch an estimation of insoluble matter is required, and this is not possible with Lintner's method (ANALYST, 1907, 32, 179).The author therefore prefers a method in which the starch is dissolved by means of dilute (about 1 per cent.) hydrochloric acid. Five grams of the finely-sieved material (or 10 grams of finely-rasped potato) arc: shaken with 25 C.C. of 1.124 per cent. (by weight) hydrochloric acid (or 0.4215 per cent. acid in the case of potatoes) in a 100 C.C. flask, the neck of which is subsequently washed free from particles with 25 C.C. of the same acid. The flask is next placed for exactly fifteen minutes in boiling water, and during the first three minutes is repeatedly shaken with a rotatory movement. Its contents are then diluted to about 90 C.C. with cold water, cooled to about 20" C., clarified with ammonium molybdate, made up to 100 c.c., filtered, and polarised.The results thus obtained agree well with those given by Lintner's method. For the estimation of the insoluble matter in starch or of starch in chocolate, etc., the method recommended is to macerate the substance for twenty-four holxrs with dilute hydrochloric acid or with water, and, if necessary, to invert the filtered solution of carbohydrates thus obtained (cf. ANALYST, 1906, 31, 25; 1908, 101). c. A. &!I. The Fat of Tonka Beans. Duyk. (Ann. de Chim. Anal. AppZ., 1908, 13, 391.)-The fat of the tonka bean (Coumarouna ezcelsa) is used in the preparation of certain kinds of confectionery, and is exported in considerable quantihies from Holland. The sample examined by the author was an orange-yellow wax-like mass with a characteristic odour of coumarin. The latter substance could be isolated by shaking the fat with it little boiling water, filtering the aqueous extract, and allowing the filtrate to stand. After a few hours an abundant deposit of white needle-shaped crystals (melting-point, 6 8 O to 6 9 C.) was obtained. Tho fat gave the following analytical values : Illelting-point, 28' C. ; specific gravity at 100" C., 0.888 ; butyro-482 THE ANALYST. refractometer reading, 47" ; critical temperature of solution (1 volume of fat, 2 volumes of absolute alcohol in an open tube), 32.5" C. ; acid value, 7 ; saponifica- tion value, 257 ; and Reichert-Meissl value (Leffmann and Beam's method), 5.4. The fat also contained a considerable proportion of volatile insoluble fatty acids. C. A. M.