262 THE ANALYST. ORGANIC ANALYSIS. The Estimation of Methyl Alcohol in Formaldehyde. R. Gnehm and F. Kaufler. (Zed. f. n;rzge?r. Clzem., 1904, xxi., 6'73.)-The formaldehyde is condensed with the sodium salt of sulphanilic acid, the methyl alcohol is distilled over, and the quantity is estimated by taking the specific gravity of the distillate. In order to reduce the sodium sulphanilate t3 a sufficiently fine state of division, 90 gramines of the salt are added by degrees to 35 C.C. of boiling water, and when solution is complete, the liquid is rapidly cooled. Of the formaldehyde solution to be examined, 20 C.C. are then added ; the flask is corked and left for three or four hours at the ordinary temperature, or one and a half to two hours at 35" to 40" C. A still-head containing glass beads is then fitted to the flask, and 30 to 35 C.C.are distilled over ; the distillate is made up to 50 c.c., and its specific gravity determined. The quantity of methyl alcohol may be calculated by means of the empirical formula : d = 1 - 0.00189 ;U 4- 0.00002 j~', which is based upon the determination of Dittmar and Fawsitt (Trans. Roy. SOC. Edin., xxxiii., 509). d is the density at 15" C. compared with wat;er at the same temperature, both being weighed in air, and 21 the number of grammes of methyl alcohol contained in the alcohol-water mixture. I n the distillates the authors have found small quantities of reducing substances having a specific gravity greater than that of water ; these consequently make the results too low. The error does not, however, exceed 0.5 to 0.6 grainme per 100 C.C.A. 31. Note on the Indophenine Reaction. F. W. Bauer. (Bci-ichtc, 1904, xxxvii., 1,244 ; through Chenz. Zeit. Rep., 1904, xxviii., 134,)-On shaking benzene containing thiopbene with concentrated sulphuric acid and isatine, the sulphuric acid is coloured blue. This coloration, known as the indophenine test, only appears when the sulphuric acid used contains a trace of an oxidizing substance, such as ferricTHE ANALYST. 263 chloride or nitric acid. obtained. is thus not entirely consistent with the fact that an oxidizing agent must also be With "chemically pure" acid a faint green coloration is The usual equation given to explain the formation of indophenine- C,H,NO, + C,H,S = C,,H,NOS + H,O- present. W. P. s.The Rapid Determination of Fat by Means of Carbon Tetrachloride. A. P. Bryant. (Joz~rn. Amer. Gizenz. Xoc., xxvi., 368.)-The author recommends the use of carbon tetrachloride for the extraction of fat from foods and feeding-stuffs. The extraction only requires two hours, and the solvent is uninflammable and of comparatively high boiling-point, besides being inexpensive. The only objection appears to lie in the fact that the last traces of carbon tetrachloride are difficult to remove completely from the fat. I t is recommended to heat for two hours at 100" C., and then to raise the temperature for a short time to 120" C. Actual tests A. G. L. have shown that this can be done without oxidizing the fat. Analysis of Linseed Oil. G. Fendler. (Berichtc, 1904, xiv., 294; through Chein.&?it. Rep., 1904, xxviii., 134.)-A number of experiments were carried out by the author in order to ascertain what is the amount of unsaponifiable matter naturally present in pure linseed oil, and to what extent, if any, this quantity is influenced by treating the oil in various ways. The results show that the quantity of unsaponifiable matter in a, normal oil does not exceed 2 per cent. Oxidation, blowing, or boiling the oil does not increase this figure. Linseed oil obtained by pressing does not contain more unsaponifiable matter than extracted oil. I n all cases a second saponification was found to be necessary, otherwise the results were too high. The best means of detecting small quantities of mineral oil in linseed oil consists in a determination of the iodine value of the unsaponifiable matter, the consistency of the latter and its solubility in hot 90 per cent.alcohol being also taken into account. The unsaponifiable matter of linseed oil is usually solid, and is soluble in hot alcohol, whilst mineral oil is liquid and insoluble in such alcohol. TIV. P. s. The Detection of Mineral Oil in Distilled Grease Oleines. Augustus H. Gill and Stephen N. Mason. ( J o z L ~ . d77zer. Clzem. SOC., xxvi., 665.)-The authors have investigated several tests for the detection of mineral oils in recovered distilled grease oleines. They isolated the hydrocarbons due to the breaking up of the fatty acids from several samples of distilled oleines by saponification with camtic potash, extraction of the unsaponifiable matter with benzol, and treatment with boiling acetic anhydride to remove cholesterol and other higher alcohols, and compared these hydrocarbons with several mineral oils likely to be used as adulterants.They find that the total bromine numbers (54.7 to 57-2), and especially the addition numbers (14.2 to 16*8), are much higher for the oleine hydrocarbons than for the mineral oils (total, 16.9 to 21.3; addition, 5.6 to 8.4). The distilled grease hydrocarbons264 THE ANALYST. show an optical rotation of 16" to 18", as against a maximum rotation of la or 2" for the mineral oils. The indices of refraction of the latter (1.4662 to 14750) are also lower than those of the oleine hydrocarbons (1.4948 to 1.4991). The fluorescence of mineral oils is in general blue, whilst that of the oleine hydrocarbons is generally green.By applying the above tests, an opinion may be arrived at as to the presence and approximate amount of mineral oils in the oleines. A. G. L. The Constituents of Chaulmoogra Seeds. Frederick B. Power and Frank H. Gornall. (Proc. Clzenz. SOC., xx., 135.) - On expression, the seeds yielded 30.9 per cent. of a fatty oil, which had the following constants: Melting-point, 22' to 23" C. ; specific gravity, 0-951 at 25", and 0.940 at 45' ; [uIr,l5', = + 52"; acid value, 23.9 ; saponification value, 213 ; iodine value, 103.2. On hydrolysis, the oil yielded glycerol, a very small amount of phytosterol, and a mixture of fatty acids consisting chiefly of several homologous acids belonging to the series C,H,,-,O,, con- taining a closed ring and one ethylenic linkage; the mixed fatty acids gave the constants : Melting-point, 44" to 45O ; [aII,, = + 52.6" in chloroform ; acid value, 215 ; iodine value, 103-2.The highest homologue (' chaulmoogric acid " present was obtained in glistening leaflets, of melting-point 68" ; boiling-point, 247" to 248" under 20-millimetre pressure ; and [a],, = + 56" ; it combines with only two atoms of bromine or iodine. The ( ( press cake " yielded, besides formic and acetic acids and a very small amount of volatile esters, an appre- ciable amount of a neutral oily substance, C1SH3202, isomeric with chaulmoogric acid, of boiling-point 314" to 215" under 18-millimetre pressure ; specific gravity, 0.9066 (16"/16") ; and [aID, = + 42.4". Palmitic acid was also shown to be present.A. G. L. On the Losses of Sulphur in Charring and Incinerating Plant Substances ; and on the Accurate Determination of Sulphur in Organic Substances. William Edward Barlow. (Joz~nz. Anzer. CJze?n. Soc., xxvi., 341.)-The author discusses the value of the various methods for determining sulphur in organic corn- pounds at considerable length, and concludes that the only accurate method consists in burning the substance in a current of oxygen, and absorbing the products of com- bustion by means of heated sodium carbonate. This process, however, must be carried out under certain conditions, all of which are satisfied by the author's method (vide ANALYST, this vol., p. 124), in which the apparatus shown in the figure is used. A. G.L.THE ANALYST. 265 Quantitative Determination of Sulphur in Organic Substances. M. E. Pozzi-Escot. (Rev. gdndr. chim. pure et appliq., 1904, vii., 240 ; through Chem. h i t . Rep., xxviii., l'iO.)-The substance is oxidized by means of chlorochromic acid, 1 gramme of the substance being agitated for several minutes in a 500 C.C. flask with 10 to 15 grammes of chromic acid and 20 to 25 C.C. of concentrated hydrochloric acid. After standing for twenty to thirty minutes the whole is heated to boiling for ten minutes, using a reflux condenser. Some unreduced chromic acid should still be present at the end of this time, X solution of chlorochromic acid itself in glacial acetic acid, to which some hydrochloric acid is added, may also be used. I n either case, the excess of chromic acid is reduced by cautiously adding alcohol, and the solution is diluted with 500 C.C.of water and precipitated with barium chloride. A. G. L. Estimation of Sulphur in Oils, Bituminous Substances, Coals, and the Like. Edmund Graeffe. (Zeit. f. aizgew Clicm., 1904, xix., 616.) The substances are burnt in oxygen in a large glass flask at about atmospheric pressure, and the sulphur is entirely converted into sulphuric acid by means of sodium peroxide. The flask has a capacity of 6 to 7 litres, and is fitted with a rubber cork, 8, through which pass a dropping funnel and two copper-wires, 1:5 to 2 millinietres in diameter. At the lower end of the shorter wire they are both covered with platinum foil, pre- ferably soldered to the copper, and are united by a thin platinum wire, 0.1 to 0.3 millimetre in diameter.To the lower end of the longer wire a platinum cone and wire are fixed, as shown in F. The under surface of the rubber cork is a protected by means of the asbestos disc, B. The temperature of the glass bottle is equalized by means of the wire cage, C, which also serves to prevent pieces flying about in case the bottle shouId burst. The platinum cone is weighed together with some cotton, on which is placed about 0.5 C.C. of the oil, and .the cone is then again weighed and hung on the lower end of the copper-wire. One end of a piece of thread is wrapped round the platinum wire, and the other introduced into the cone. The bottle having been filled with oxygen, the stopper is tightly fixed. The dropping funnel is filled with 50 C.C.of a solution of sodium peroxide in ice-cold water. The ignition is started by means of an electric current, and at the same time the rubber stopper is held down with the hand or wired down. The excess of pressure generated is reduced either by cooling under the tap or by allowing gas to escape gradually through the funnel. The contents of the funnel are then allowed to run into the bottle, the rubber stopper is266 THE ANALYST. removed and an ordinary cork substituted, the bottle being allowed to stand about an hour for mist to settle. The contents of the bottle are then washed out, filtered, acidulated, and precipitated with barium chloride in the usual way. If there be no electric current available, the arrangement shown at D is used, and a thread is led right up to the stopper.This is lit with an ordinary match, the stopper is immedi- ately replaced, and the estimation is carried out as above. When volatile oils are to be tested they are weighed in small glass tubes, which are closed with a stopper of paraffin wax. A. 11. Determination of Sulphur in Caoutchouc. Paul Alexander. ( GWILUL~ Ztg., xviii. , 729 ; through Chcnz. Zcit. Rep., xxviii., 180.)-The author defends Carius’s method against the statements made by W. Esch (ClLem. Zeit., sxviii., SOO), and reviews the barium chromate method of Pennock and Morton (JOZL~IL. JIILCI.. Chenz. XOC., xxv., 1265) and Pontio’s manganese peroxide and soda method (Eev. gc:itdi-. clzim. p w e et appliq., vii., 13). W. Esch (GZLYTUIL~ Ztg., xviii., 752 ; through C‘lLem. Zeit. Rep., xxviii., 130) points out that P. Alexander’s use of Henrique’s formula for the calculation of the caoutchouc from the sulphur content is incorrect, as this formula really only holds good for certain simple cases. Further, he states that, in using Carius’s method, instead of fusing only the residue insoluble in nitric acid with sodium carbonate, it is better to evaporate the total contents of the tube to dryness and fuse the whole residue, as the presence of lead may otherwise cause errors in the subsequent precipitation of the sulphuric acid. A. G. L. The Estimation of Carbon by means of Phosphoric Acid. Gilbert T. Morgan. (Proc. Chena SOC., xx., 167.)-Phosphoric acid is substituted for sulphuric or hydrochloric acid in the determination of carbonates and in the chromic acid method of combustion, the use of a non-volatile acid obviating the danger of acid fumes being carried into the absorption apparatus. A. G. L.