TEE ANALYST. 375 ORGANIC ANALYSIS. The Fatty Oil of the Seeds of “Carthamus Tinctorius.” G. Fendler. (Communication of Pharm. Inst. of Berlin University to Chem. Z e d , 1904, lxxiv., 867.)-This oil, procured by extraction of the seeds with ether, is of a golden yellow colour, and, though at first inodorous, rapidly becomes rancid. In thin films the oil dries completely within six days, the gain in weight being : ,? 40 8 , ... ... 4.3 ,, 9 , 64 9 7 . . . 6.4 ,, ,) 136 9 , ... ..- 7-5 ,, After 18 hours ... . . . 0.6 per cent. The constants are : Specific gravity, 0.9266 ; melting-point, - 5’ C. ; Reichert- Meissl number, 0.0 ; saponification number, 191.0 ; iodine number (Hubl), 142.2 ; unsaponifiable matter, 0-708 per cent. ; Zeiss butyro-refractometer at 40’ C., 65 ; free376 THE ANALYST.fatty acids (as oleic acid), 5.84 per cent., figures well agreeing with those given by Benedict-Ulzer (Analyse der Fettej. The fatty acids have the following constants : Specific gravity, 0.9135 ; melting- point, 17" C. ; saponification number, 199.0 ; mean molecular weight, 251.8 ; acetsyl acid number, 154.5 ; acetyl number, 52.9 ; acetyl saponification number, 207.4 ; iodine number, 148.2. H. A. T. Analytical Notes on Mineral Oils. Rudolf Nettel. (Chem Zeit., 1904, lxxiv., 867.)-For the determination of water in crude oil, 100 C.C. of the oil are mixed with an equal volume of benzene in a separating funnel, shaken for five minutes with 50 C.C. of -& HCl, and then allowed to stand at 65" for half an hour. The greater part of the acid separates; 25 C.C.are drawn off, and titrated with & alkali. The water present in the oil acts as a diluent of the Fc acid, and the difference between the observed and the original acidity gives the percentage of moisture. Two determinations on the same sample gave the following figures : A. 25 C.C. & HC1 required 23.7 C.C. & NaOH-2.6 per cent. of water. B. 25 C.C. ,, ,, 23.8 C.C. ,, =2*4 per cent. ,, In a sample of dry oil 25 C.C. ihi HC1 required 24.98 C.C. & NaOH, indicating coin- plete absence of moisture. After addition to this sample of 6.2 per cent. of distilled water, 25 C.C. required 21.9 C.C. & NaOH, equal to 6.4 per cent. of water. For the determination of the solidifying-point of lubricating oils, the author drops a grain of shot (diameter, 14 millimetres) from a standard height into the oil at each successive lowering of the temperature by I" C., the point at which the shot remains on the surface being taken as the solidifying-point of the oil.H. A. T. Analysis of Otto of Rose. W. H. Simmons. (Chemist and DyzLgqist, 1904, lxv., 703.)-In continuation of his previously published work on the iodine absorp- tion of Otto of rose (ANALYST, 1904, 175) the author has applied the process to several samples of this season's oil, with results which fully confirm his former opinion as to the value of this test in judging the purity of Otto of rose. Five oils, which from their other constants appeared to be genuine, had iodine values varying from 189 to 192. Five other samples of a, suspicious character gave values from 199 to 209.To test the value of the refractive index for detecting adulteration in Otto of rose this constant was determined for thirty-six samples, twenty-three of which there was every reason to believe were genuine, the other thirteen being of doubtful quality. The genuine oils had refractive indices, varying from 1.4592 to 1.4654, whilst the other samples gave values from 1.4615 to 1.4770. X sample purposely adulterated with 25 per cent. of artificial Otto gave a reading of 1.4655, and another, containing 15 per cent. of palmarosa oil, 1.4612. These results show that the generally accepted limits, 1.4600 to 1.4650 or even 1.4670, are too wide for the constant to have much value, as they cover many adulterated samples. On the other hand, the iodine valueTHE ANALYST.377 readily revealed the adulteration in the last-mentioned samples, the values being 215 and 205 respectively, and, in fact, was the only figure which did so. w. P. s. The Estimation of Tanning Matter without the Use of Hide Powder. H. Wislicenus. (Zeits. f. a?~gezu. Chem., 1904, xxv., 801.)-Instead of hide powder the arxthor uses aluminium oxide or hydroxide, prepared by the action of dilute caustic soda upon aluminium in the presence of mercury. I t is claimed that this absorbent is cheap and easily prepared in a uniform condition, that it is rapid in its action, and yields concordant results. For the preparation of the porous alumina absorbent 100 grammes of aluminium filings in grains of about 1 millimetre diameter are shaken with a 5 per cent.aqueous caustic solution, and as soon as hydrogen begins to come off freely the liquid is poured away and the filings washed well under the tap. After this treatment with caustic soda and washing has been repeated, a little mercuric chloride solution is added, and the filings are washed again. The aluminium-mercury couple is then allowed to stand with an equal quantity of water, to which some ether and alcohol may be added. The heat set free by the oxidation causes the liquid to evaporate, and a dry mass is obtained, from which fine aluminium hydroxide can be separated by sifting through a fine sieve. The material may either be dried in a desiccator, in which case it has the composition Al(OH),, or it may be ignited, and so con- verted into A120,.In making an estimation, 2.5 to 3 grammes of the hydroxide, or 2 to 2.5 grammes of the oxide, are gradually added, with constant shaking, to 50 to 100 C.C. of the tannin solution. The whole is then allowed to stand for some hours until the liquid is clear, and a drop of it gives no colorat'ion with an iron solution. The material absorbs far more rapidly than hide powder. The alumina may now be filtered off on to a tared filter, washed with cold water, dried, and weighed. The amount of tannin is given by the gain in weight of the powder; the estimation can be checked by burning off the tannin and reweighing the alumina, but there is danger of losing some of the fine powder during the ignition. As an alternative, the total extract and " non-tannin " may be estimated by evaporation, as in the hide powder process.Sugars are not absorbed by the alumina powder; gallo-tannic acid is, biit can be removed almost completely by washing with hot water. Comparative experiments showed that in the case of commercial tannins and chestnut extracts the results are almost identical with those obtained by the hide-powder process, but that with pine and oak bark and oak wood the agreement is not so good. A. 111. On the Presence of Hydroquinone in the Bear-Tree. G. Rivihe and G. Bailhache. (BUZZ. SOC. Chzm., 1904, xxxi., 1104-1107.)-The authors have isolated hydroquinone from the leafy buds of the pear-tree, from 3 to 5 grammes per kilo. being found. The material was digested for several days with cold alcohol, the alcoholic extract evaporated, and the residue treated with boiling water and filtered378 THE ANALYST.from the chlorophyll and resins. The filtrate was shaken with ether at intervals for forty-eight hours, and the ethereal extract on evaporation left a mass of crystals of impure hydroquinone, which, when purified, gave all the usual reactions. C. A. MI. Determination of Lecithin in Plants. E. Schulze. (Chem. Zeit., 1904, xxviii., 751, 752.)-The author mentions that both the ethereal and the alcoholic extracts of the plant should be used for the determination of the lecithin, as the latter is dissolved by both solvents, I t is also shown that absolute alcohol extracts no phosphorus- containing compound other than lecithin from plants or seeds. With regard to the statements that lecithin is slowly decomposed at temperatures above 60" C., and that this temperature should not be exceeded during the alcohol extraction, it should be pointed out that a considerable proportion of the lecithin exists in plants in combina- tion with albuminous substances, and that the treatment with alcohol has for its purpose the breaking-up of these compounds.Whether this is attained at a temperature below 60" C. remains to be proved experimentally. I t is usually assumed that 100 parts of lecithin contain 3.84 parts of phosphorus corresponding to the phosphorus contents of distearin-lecithin, or the average amount of phosphorus (3-94) contained in dipalmitin, distearin, and diolein-lecithin is taken as the factor for calculating the phosphorus found in lecithin.Lecithin, however, occurs in combination with other fatty acids, lecithin compounds, containing from 2-52 to 2.3 per cent. of phosphorus, have been obtained from rye, barley, and malt. The correct factor is, therefore, not accurately known. w. P. s. Analysis of Tobacco. R. Kissling. (Chem. Zeit., 1904, xxviii., 775, 776.)-The folIowing methods are given for the determination of nicotine, resins, and non-volatile organic acids (citric, malic, and oxalic) in tobacco. Nicotine.-Ten grammes of the powdered tobacco are mixed with 10 grammes of powdered pumice stone and 10 grammes of sodium hydroxide solution (50 grarrirnes per litre). The somewhat moist mass is extracted with ether in a suitable apparatus for several hours. After slowly evaporating off the ether, the residue is dissolved in dilute potassium hydroxide solution and steam-distilled. Each 100 C.C.of distillate is separately titrated with standard sulphuric acid, using luteol as indicator, the fifth distillate being usually free froin nicotine. One molecule of sulphuric acid corresponds to 2 molecules of nicotine. Resins.-Thirty grammes of tobacco are extracted with light petroleum spirit for eight hours, and the residue from the petroleum spirit extract dried at 80" C. for two hours and weighed, This residue, consisting of resin, wax, nicotine, and volatile fatty acids, is dissolved in absolute alcohol and cooled to 0" C. The wax separates Out, and is collected on a filter. After evaporating the alcohol from the filtrate, the latter is acidified with sulphuric acid and steam-distilled to remove volatile acids.The distillation residue is then rendered alkaline, and again steam-distilled to drive off the nicotine. The resin is finally obtained from the residue in the flask in the usual way.THE ANALYST. 379 The tobacco which has been extracted with petroleum spirit is now freed from the latter, and extracted with ether. I t is sufficient to treat with hot water the small amount of resin, etc., obtained to remove nicotine, and then to dry the residue of resin at 90" C. The tobacco, after removing the ether, is extracted a third time with 99 per cent. alcohol. The extract, after evaporating the alcohol, is acidified and steam- distilled. The resin is then separated from the aqueous residue, dissolved in alcohol, filtered, evaporated and dried at 100" C.The amounts of resins obtained by the author from six samples of tobacco (Brazilian and Havana) were : petroleum-spirit- soluble, 3.50 to 8.63 per cent. ; ether-soluble, 0.39 to 1.19 per cent. ; alcohol-soluble, 1.71 to 2-68 per cent. Non-uoZatile Organic Acids.-A mixture of 10 grammes of tobacco, 10 grammes of powdered pumice stone, and 10 grammes of dilute sulphuric acid (20 per cent.) is extracted with ether for twenty hours. The residue obtained from the extraction after distilling off the ether is dissolved in water, and made up to 100 c.c ; 50 C.C. of this solution are titrated with barium hydroxide solution, and the barium salts separated by adding alcohol to the solution until it contains 20 per cent. of alcohol.The mixture is quickly filtered, and the precipitate consisting of almost pure barium citrate washed with 20 per cent. alcohol. On adding sufficient alcohol to the filtrate to bring the strength of the latter up to 70 per cent., barium malate is precipitated. The oxalic acid is determined in the remaining 50 C.C. of the solution by the usual methods. The following results were obtained in the above-mentioned samples of tobacco : oxalic acid, 1.84 to 2-77 per cent. ; malic acid, 1.53 to 3.95 per cent. ; citric acid, 3.25 to 7.33 per cent. All the results are calculated on the dry tobacco. w .P. s. On the Treatment of Urine before the Determination of Urea. C. Frabot. ( A m . de Chim. anal., 1904, ix., 372, 373.)-Urine treated by means of lead acetate, phosphotungstic acid (Moreigne's reagent), etc., gives the characteristic blue coloration when tested by the method described in the abstract on p.384. The author, there- fore, concludes that in the ordinary methods of treatment the uric acid is not completely precipitated. C. A. M. Volumetric Determination of Methylene Blue. L. Pelet and V. Garuti. (BUZZ. SOC. Chim., 1904, xxxi., 1094-1097.)-The method is based on the precipitation of the methylene blue by means of certain acid dye-stuffs that combine with it to form more insoluble compounds, the end-point of the reaction being shown by the change of colour in the solution. The most suitable dye-stuffs were found to be crystalline Ponceau, carmine in the state of the sodium salt, orange pyramine, and cotton brown. Certain acid yellows-e.g., yellow naphthol S.-yielded an insoluble derivative, but it was nearly impossible to distinguish the change of colour at the final point of the reaction.In the determination a definite volume of the solution of methylene blue is treated with the solution of the reagent, which is added, little by380 Ponceau. Carmine. THE ANALYST. Orange pyramine. Cotton Brown. little, until the change of colour is seen in the stain made by a drop of the liquid on filter-paper. The solutions of acid colouring matters are first standardized on 8 solution of pure methylene blue before being tried on commercial samples. The following results were obtained with two samples, of which definite quantities were weighed and allowance made for the proportion of ash and moisture present : No.1 No. 2 I I Amount found by Titration with ~ _ _ _ ~ - ~ ~ _ _ - Gramme. (tramme. Gramme. Grainine. Gramme. 0.684 0.688 0.684 0.677 0.668 0.705 0.699 0.687 0.703 0.699 The conipound formed with crystalline Ponceau has the formula C,,H,,N,S,07, and contains 2 molecules of blue to 1 of Ponceau, whilst the carmine compound probably has a composition corresponding to the formula C,,H,,N,SO,,. The error in the determination is within about 3 per cent. c. -4. M. Parchment-paper Containing Boric Acid. K. Windisch. (Zezt. U?itersmh. Xahi.. imd Gemssnzittel, 1904, viii., 417.)-Out of 124 samples of parchment-paper examined, only 17 were quite free from boric acid (or borax), whilst 101 samples gave a strong, and 6 samples a feeble, reaction for boric acid.I n four cases the quantity of this acid was determined, the amounts found varying from 0.384 to 1.130 grarunie per 100 grammes of paper. This investigation was undertaken because faint traces of boric acid were detected in the outside parts of a sample of margarine, whilst the interior of the same contained none. The paper in which the sample was wrapped probably contained boric acid. An experiment was then carried out, in which margarine was wrapped in paper containing boric acid, so kept for a few days, and then tested. The result showed that margarine readily takes up boric acid from these wrappers, the outer layers of the sample having absorbed as much as 0.0186 per cent. of boric acid in ten days. w. P. s. The Effect of the Alkalinity of Glass on the Accuracy of Kjeldahl Nitrogen Determinations. K. Barelt and H. Schoenewald. ( Woclzeizsclw. Bmuemi, 1904, 523 ; through Chem. Zeit. Ilep., 1904, xxii., 969.)-In these experiments a long air-cooled tube of soda-glass was used as condenser for the distillation of water under conditions similar to those of the Kjeldahl process, and the distillation con- tinued for from one-half to three hours. With an old tube which had been frequently employed for this purpose, the error only once exceeded 0.4 per cent. (calculated as albumin). Using new glass this figure was greater by some 0.1 to 0.15 per cent. (of albumin), and the authors suggest that all glass should be thoroughly steamed before use.THE ANALYST. 381 Attention is drawn to the fact that in an actual ammonia distillation the error would be greater, owing to the solubility of the alkalies in steam containing ammonia. H. A. T.