TEE ANALYST. 329 ORGANIC ANALYSIS. Estimation of Formaldehyde. A. Pfaff. (Chem. Zeit., 1902, xxvj., 701.)- This process depends on the formation of a condensation product between formalde- hyde and hydrazine, according to the equation : A solution of hydrazine hydrate, standardized with decinormal sulphuric acid, is added iu excess to the liquid under examination, and after standing in a closed vessel for one hour, the excess of the reagent is determined by titration with the same acid, using methyl orange as indicator. The hydrazine hydrate solution does not keep its strength, but needs verification before each analysis. In standardizing it, it must be remembered that 1 molecule of sulphuric acid combines with 2 molecules of hydrazine, yielding the diammonium semisulphate [N,H4]2€I,S0,.The colour of the liquid obtained in this operation may be employed for comparison in the regular titration. 2CH,O + N2H4H,0 = C,H,N, + 3H,O. The results quoted agree with those given by Romijn’s iodine method. F. H. L. Estimation of Anthranilic Methyl Ester. A. Hesse and 0. Zeitschel. (Ber., 1902, xxxv., 2355; through Chem. Zeit. Rep., 1902, 215.)-The authors con- sider that the process which Erdmann has proposed (ANALYST, 1902, xxvii., 125) for this purpose has one advantage over that which they themselves have recommended (Bey., 1901, xxxiv., 296), inasmuch as it does not return the methyl ester of methyl- anthranilic acid or any other secondary or tertiary bases which may occasionally be present in the oil ; but in all other respects their own method is preferable.Erd- mann’s process is not quantitative, while the action of the strong acids upon the oil renders it unfit for further examination. Perhaps, when methylanthranilic acid is expected, the bases may be isolated by means of Hesse and Zeitschel’s process, and the product divided, titrating one half according to Erdmann, the other in their own fashion. I?. H. L.THE ANALYST. Determination of Oil in Linseed. A. Goetzl. (Oestew. Chem. Zeit., 1902, v., 413.)-The author has studied the comparative value of petroleum spirit and ethyl ether as solvents for the oil contained in linseed. The seeds were all finely powdered, dried for two hours at 95” C. in a n atmosphere free. from oxygen, and their albuminous constituents were coagulated with alcohol.The extraction of the seeds is more perfect with ethyl ether, but petroleum ether yields the purer product. All the foreign substances of the oils, such as cholesterin, etc., except (‘ linoxyn,” are more soluble in ethyl ether than in petroleum ether. The colouring matter of the seeds is taken up more readily by ethyl ether. Of the two liquids petroleum ether is easier to remove from the extracted oil. F. H. L. Some Colour Reactions of Fatty Oils. H. Kreis. (Chem. Zeit., 1902, xxvi., 897.)-When Bellier’s test for sesamd oil (ANALYST, 1900, xxv., 50) is carried out as he described it, but with the resorcinol replaced by phloroglucinol, no colour is pro- duced; if, however, either hot benzene or ether is used as the solvent, the red tint develops. The best reagent is a 1 : 1,000 solution of phloroglucinol in ether shaken with equal parts of 1.40 nitric acid and the sample under investigation.So examined, arachis, sesam4, cotton, walnut, peach-kernel, castor, and perhaps other oils, give strong raspberry-red colours in the non-aqueous portion of the test ; while olive oil, lard, and butter remain colourless, or yield pale orange tints. If the process is modified by moistening 0.05 gramme of solid phloroglucinol with 3 to 5 drops of oil, and then adding an equal volume of nitric acid, sesami? behaves in a very character- istic manner-the acid becomes greenish-blue, the oil red ; on introducing ether it becomes violet; ; and on shaking with water the ether turns red-brown, and the water is stained dark-blue. This water-soluble blue dyestuff is better obtained by shaking about 0.01 gramme of phloroglucinol wjth 2 C.C.of a 1 : 4 solution of sesame oil in carbon tetrachloride, adding 1 C.C. of nitric acid as before and extracting with water. Resorcinol, with or without carbon tetrachloride, gives similar reactions with sesame, but water and ether quickly decolorize the liquids. The author has already shown that Bellier’s reaction sometimes fails altogether, or appears but faintly, after prolonged agitation, when the oils are old; and he has also found that such oils, shaken with fresh sesamd and 1-19 hydrochloric acid, give the green noticed by Bishop in the case of old sesame (cf. ANALYST, 1900, xxv., 49). This peculiarity has been observed with arachis, poppy, walnut, peach-kernel, cotton, and sesam6 oils ; and now it appears that in the same circumstances these oils refuse to give the reaction with phloroglucinol.Thus it happens that the failure of the Bellier test does not of itself prove the purity of a specimen of olive oil, and it is necessary to try such a sample with fresh sesame oil and hydrochloric acid to insure the non-appearance of the Bishop green. The author points out (Chem. Xeit., 1902, xxvi., 932) that when an ethereal solu- tion of phloroglucinol is used the solution at the end of the experiment should be diluted with water ; otherwise a lively disengagement of nitric oxide may take place in a short time. F. H. L.TEE ANALYST. 331 The Analysis of Commercial Lecithins. Imbert and Merle. (Bull. de Pharm. Xzhd. E’st., May, 1902; Ann.de Chim. anal., 1902, vii., 350-351.)-The amount of phosphoric anhydride in lecithins varies from 8-75 to 9.45 per cent., according to the molecular weight of the lecithin. On boiling a lecithin with a mineral acid it is decomposed into phosphoric acid, a salt of choline, and free fatty acids, whilst alkalies convert it into alkali glycero-phosphate, choline, and alkali salts of the fatty acids. The authors’ method is based upon these reactions, and also on the fact that mono-alkyl phosphoric acids are mono-basic with methyl orange, but dibasic with phenol-phthalein as indicator. If, then, after decomposition of the lecithin with an acid or an alkali, the liquid be exactly neutralized, with methyl orange as in- dicator, the amount of phosphoric anhydride can be calculated from the amount of alkali subsequently required to effect neutralizstion, with phenol-phthalein as indicator; since 2 molecules of alkali correspond with 1 molecule of phosphoric acid or 2 molecules of glycero-phosphoric acid.In applying this method about 0-5 gramme of the sample is boiled for an hour with 50 C.C. of 5 per cent. sulphuric acid and then filtered, or 0.5 gramme is treated for thirty minutes with 50 C.C. of a 2 per cent. solution of potassium hydroxide. In each case the liquid is titrated with the two indicators as described above. The method is only applicable in the absance of phosphates soluble in water or in cold acids. Further information as to the quality of a lecithin can be obtained by determining the proportion of nitrogen it cohtains, as the ratio of phosphorus to nitrogen is approximately - = 2.21, whatever the nature of the lecithin.31 14 C. A. M. New Reactiou for Cholesterin. E. Hirschsohn. (Pharnz. c. H., 1902, d i k , 357 ; through Claem. Zeit. Rep., 1902, 20l.)-On heating with distilled trichloracetic acid, cholesterin dissolves with a fine red colour. The tint gradually deepens, becoming raspberry-red in fifteen minutes, blue-violet in twelve hours, and blue after twenty-four hours. One milligramme of cholesterin treated with 10 drops of trichloracetic acid and 1 drop of acetyl chloride gives an orange colour in half an hour, which darkens to a strong cherry-red in twenty-four hours, showing a greenish- yellow fluorescence. F. H. L. The Co;nposition of ‘‘ Kaki-Sibu.” E.Pozzi-Escot. (Ann. de Chirn. anal., 1902, vii., 299, 300.)--Kaki-~ibu is a, commercial antiseptic product prepared from the juice of a plant, and widely employed in Japan for coating substances with a preservative surface. The sample examined by tbe author was a viscous reddish- brown liquid, with a strong odour of butyric acid. It was soluble in water, the solution giving a deep blue colour with ferric chloride, and becoming rapidly brown on the addition of an alkali. On exposure to the sir the sample became coated with a firm pellicle, which was insoluble in water. When distributed over a textile fabric it formed a hard, very resistant eoating. On analysis it gave the following results :332 THE ANALYST. Specific gravity Total solids dried at'i05" b.*' Tannin ...Volatile acid (as acetic acid') ' ,, 115" C. Aih .I: ... ... ... Fixed acid (as lactic acid) ... Nitrogen ... ... ... The tannin was not a glucoside. ... ... ... 1.025 ... ... 5-82 per cent. ... 5-64 7 9 ... ... ... 0.345 ,) ... ... ... 3.59 ,, ... ... ... 0.234 ,, ... ... ... 0.115 ,, ... ... . I . 0.00 ,, ... ... ... c. A. RI. Determination of Oxalic Acid in Urine. W. Autenrieth and H. Barth. (Zeds. physiol. Chem., 1902, xxxv., 327 ; through Clzem. Zeit. Rep., 1902, 200.)-The entire quantity of urine voided in twenty-four hours is mixed with an excess of calcium chloride solution, ammonia is added to a strong alkaline reaction, the whole is well shaken and set aside for eighteen or twenty hours, The precipitate is collected on a paper, washed with a little cold water, drained well, transferred to a beaker, and dissolved in the minimum of hot hydrochloric acid (30 C.C.of 15 per cent. acid are usually sufficient). The resulting solution is extracted by successive agitation four or five times with 550 to 200 C.C. of ether containing 3 per cent. of alcohol. The extracts are brought into a large dry flask, and allowed to rest for one hour in order to separate the last portions of water, then passed through a dry filter. Next, 5 C.C. of water are introduced to prevent the formation of the diethyl ester of oxalic acid, and the ether is distilled off, shaking the aqueous residue, if necessary, with blood charcoal, and filtering it. The product is concentrated on the water-bath to 3 or 5 c.c., treated. with calcium chloride solution and excess of ammonia, allowed to stand for a time, and then faintly acidified with acetic acid.The calcium oxalate is finally collected and washed, being estimated either by ignition into oxide or by titration, the former being preferable. The authors' experiments show them that oxalic acid is a normal, and very probably a constant, constituent of human urine. F. H. L. The Determination of Uric Acid in Urine. E. Richter. (Zeit. anal. Chew., 1902, xli., 350-359.)-The author recommends the following method, devised by Jolles, as the most exact method of determining uric acid in urine. From 10 to 15 grammes of ammonium acetate are dissolved in 100 C.C. of the clear urine, which is then rendered faintly alkaline with ammonia, and allowed to stand for five to six hours.The precipitated uric acid is then collected on a filter, and washed with a 10 per cent. solution of ammonium carbonate until the filtrate is free frain chlorine. The precipitate is then washed by mean8 of hot water into a beaker, and boiled for about an hour with 0.1 gramme of magnesia to remove the excess of ammonium carbonate, after which 10 C.C. of sulphuric acid (specific gravity 1.4) are introduced, and the liquid oxidized by means of a 0.8 per cent, solution of potassium per- manganate. This is first added to the boiling liquid 1 C.C. a t a time until it is no longer rapidly decolorixsd, and then only 6 to 8 drops are added. When the separatedTHE ANALYST. 333 manganese peroxide no longer dissolves in the liquid when evaporated from about 500 C.C.to 100 C.C. (not less), there can be no doubt as to the whole of the uric acid having been oxidized to urea. The liquid is now evaporated to about 30 c.c., and any manganese peroxide dissolved by the addition of a few drops of oxalic acid, after which the beaker is immersed in cold water and continually agitated, whilst sodium hydroxide solution (32" Be) is added 1 C.C. at a time until the reaction becomes alkaline to litmus. The liquid is then transferred to a Reichert's nitro- meter, and shaken with 25 C.C. of a solution prepared by dissolving 80 grammes of sodium hydroxide in water, adding 25 grammes of bromine, and diluting the liquid to a litre. The amount of nitrogen liberated is corrected for temperature and pressure, and calculated into the corresponding amount of uric acid.In this way the author obtained results ranging from 98.5 to 100.3 per cent. of the amount of uric acid used in test experiments. As a rule, the results given by this method were from 1 to 2.5 per cent. higher than those yielded by the Ludwig- Salkowski method, which, however, has been admitted by its authors to give results about 2 per cent. too low. C. A. M. The Oxidation and Estimation of Uric Acid and Urates. J. F. Tocher. (Pharm. Journ., 1902, 161-166.)-As urates are quantitatively converted into urea by boiling with dilute sulphuric acid and chromic anhydride, the uric and urea nitrogen can be determined in urine as follows : A measured volume of the urine is saturated with solid ammonium chloride, and the ammonium urate collected on a filter and washed with ammonium chloride solution.The ' urate is then dissolved in dilate soda solution, and boiled to drive off the ammonia; after acidifying with dilute sulphuric acid 2 to 3 grammes of chromic anhydride are added, and the solution is boiled. I t is then cooled and transferred to a nitrometer, and the nitrogen liberated with hypobromite as usual. One C.C. of nitrogen is equivalent to 0.00375 gramiiie of uric acid. An alternative method is to boil 10 C.C. of the sample with about 2 C.C. of dilute sulphuric acid and 2 grarnmes of chromic anhydride for two minutes. The solution is then cooled and made up to 10 C.C. ; 1 C.C. of this is measured into a hypobromite tube, and the liberated nitrogen read off. On separately estimating the urea, in 1 C.C.of the urine, from which the urates have been precipitated a8 barium urate, and deducting the amount found from that obtained by the chromic anhy- dride treatment, the difference multiplied by 1.4 gives the uric acid. w. P. s. A New Method of Organic Analysis. P. Thibault and A. 0. Vournasos. (BUZZ. SOC. Chim., 1902, xxvii., 695-901.)-1t is stated that by means of €he apparatus devised by the authors all the disadvantages of the ordinary method of combustion are obviated, and several analyses can be made in a day. 1 6 consists of a vertical steel tube, 20 centimetres in length and 5 centimetres in diameter, terminating below in a spherical bulb. On the side of the tube near the top is brazed a narrow steel tube, bent once at a right angle, and provided outside with a tap for the introduction of oxygen.The other end of this tube passes down into the bulb of the combustion tube. The top of the latter is provided with a collar, into which a cap can be fitted334 THE ANALYST. and hermetically closed, whilst a narrow steel tube lesds from the cap and is con- nected with the ordinary absorption bulbs. The tube is heated from the upper part downwards by means of a blowpipe. When the upper part of the tube becomes bright red the lower part is heated by means of a second blowpipe. A weighed quantity of the substance is introduced, and the tube filled with cupric oxide, which is pressed down as much as possible. The cover is then fixed on and connected with the absorption bulbs, and the tube heated as described above. As soon as bubbles of gas cease to be evolved the tap of the side tube is opened, and a slow current of oxygen passed through for about fifteen minutes, In the case of readily combustible bodies the combustion is complete within an hour, whilst for less combustible bodies the time is slightly increased, but in every instance the results are stated to be much more exact than those obtained by other methods. The apparatus can also be used for the combustion of liquids and gases. In the case of volatile liquids a weighed quantity of the substance is placed in a tube pro- vided with a tap at each end, one being connected with the side tube of the apparatus, whilst a current of oxygen, heated by passing through a red-hot tube, enters by the other. The tube is first heated, and when the cupric oxide becomes red-hot the mixture of liquid and hot oxygen is slowly introduced. A similar plan is adopted for the combustion of gases, but in this case the oxygen is used at the ordinary temperature. C. A. M.