THE ANALYST. 13 ORGANIC ANALYSIS. Detection and Estimation of Methyl Alcohol in Ethyl Alcohol. Trillat. ( A m et Rev. Chinz. AizaZyt., vol. iii. [9], pp. 294-300.) -The author finds that ethylal and niethylal are constantly formed amongst the products of the oxidation of ethyl alcohol, and that these furnish, when combined with dimethylaniline, bases diflering in properties. The base obtained from ethyl alcohol corresponds to the formula C,H,: 2[C,H4N : (GH3)J, and when dissolved in dilute acetic acid and treated with lead dioxide yields a blue solution, changi=lg immediately to green, afterwards to yellow, and becoming completely colourless when boiled. On the other hand, the base from methyl alcohol (CH, . [C,H4N : (CH3)J) gives a persistent blue coloration, which is rendered more intense by boiling, and enables 1 part of the base to be detected in 200,000 parts of solution.The same phenomenon is developed when the two alcohols are mixed, but in order to secure oxidation when the proportion of methyl alcohol is small, it is necessary to dilute the mixture with 10 volumes of water calculated to absolute alcohol, and it is advisable to employ 1.5 part of potassium dichromate to each part of absolute alcohol present. Another essential preliminary to the reaction is the careful rectification of the dimethylaniline to remove impurities, I n applying the test, 20 C.C. of the sample of alcohol are added to 300 C.C. of water and 30 grammes of powdered potassium dichromate, then cooled and mixed with 100 grammes of 20 per cent. sulphuric acid. After the reaction has proceeded for one hour the liquid is distilled, the first 50 C.C.(rich in acetaldehyde) being rejected. The distillate is neutralized with sodium carbonate and made up to 400 C.C. One-fourth of this is heated on a water-bath for five hours at 65" to 70" C. in a small closed flask, with 2 C.C. of rectified dimethylaniline and 1 C.C. of 10 per cent. sulphuric acid, with occasional agitation. After neutralizing with alkali and distilling off the excess of dimethylaniline, a, portion of the liquid is acidified with acetic acid, then treated with a few drops of water containing lead dioxide in suspension, and boiled in order to develop the blue coloration indicative of methyl alcohol. The coloration is compared in the usual manner with typical samples prepared beforehand, and is sufficiently decisive to detect 1 per cent. of methyl alcohol.When the latter exceeds 5 per cent., the base may be weighed direct. c. s. The Estimation of Caramel. Fradiss. (Bull. Ass. Chinz., 1898, xvi., 280.)- The substance under examination is mixed with methylic alcohol, which is evaporated on the water bath. The residue is dried first in vacuo, and then thoroughly in a,14 THE ANALYST. 0.9199 1.4687 110.4 197.5 0.83 aurrent of dry air. I t is then extracted for two hours under a reflux condenser with methylic alcohol (95 per cent.), which dissolves all the caramel. The filtered extract is mixed with an excess of amylic alcohol which precipitates the caramel, and the precipitate, after being dissolved and reprecipitated two or three times, is finally dried on a weighed filter at 90" C.Various samples of molasses examined by this method were found to contain from 1.10 to 2.50 per cent. of caramel. C. A. M. 0-9207 09208 1,4687 1 1.4681 109.1 1 107.9 197.0 ~ 198.1 0.57 i 0.68 The Characteristics of Curcas Oil. 0. Klein. (Zeit. angew. Chem., 1898, 1012-1015.)-The Jatropha Curcns, from the seeds of which this oil is obtained, grows to a height of 3 or 4 metres, and is cultivated in all the Portuguese colonies, but especially in the Cape Verde Islands, which supply about three-fourths of the total quantity shipped to Portugal. There are two factories where the oil is extracted in Lisbon, the finely-divided seeds being subjected to hot pressure. The oil is used for lubricating and lighting, and in the soap and candle manufactures, and the pressed residue fetches a high price for manure.The physical and chemical constants of the oil extracted in different ways by the author and of a commercial specimen were : ... .. . ... Specific gravity ... Refractive index at 25" C. Iodine value ... ... Saponification value . . . . Free acids ... 6 . . Volatile acids ... ... 109.8 203.5 4-96 1 Pressed. Pressed. , ! Hot -- 0.9240 1,4689 109.1 203.6 4.65 5.5 Extracted ~ Commercial. 'Old 1 with 1 Hot Pressed' Ether. ! Pressed. - I - I - The oil is of a yellowish-red colour, which varies in shade according to the degree of pressure and heat to which the seeds were subjected. It has a characteristic odour, which cannot be readily mistaken. The acetyl values of the hot-pressed and extracted oil were 34.7 and 51-7 respectively by Benedikt and Ulzer's original process.By Lewkowitsch's method (Journ. SOC. Chem. Ind.), the corresponding figures were 17.6 and 25.3. The melting-point of the fatty acids determined in a capillary tube was 29.5" to 30.5" C., and the solidifying point 25-75'' to 26.5". The oil is soluble in alcohol to the extent of 24.12 per cent. I t is insoluble in cold glacial acetic acid, but readily dissolves in the hot acid. The viscosity in Engler's apparatus at 20" C. was 9.45, so that in this respect curcas oil comes between crude rape-seed oil and olive oil, the latter having a viscosity of 9.03 to 10.3 (Kiinkler). The phytosterin determined by Bomer's method was 0-58 per cent. According to Hiepe (Rep.d. anal. Clzem., v., 22G), curcas oil is frequently used to adulterate olive oil in Portugal, but the author states that he has never yet met with any instance of such adulteration, although he has examined hundreds of suspicious samples of olive oil. Moreover, he considers such an admixture extremely improbable, taking into account the facts that 10 drops of curcas oil have a greater purgative effect than a tablespoonful of castor oil, and that an .addition of 10 per.THE ANALYST. . 15 cent. of curcas oil to olive oil imparts an unmistakable odour. For its detection in olive oil Hiepe recommends treating the oil with nitric acid and copper filings, the resulting elaidin being of a reddish-brown colour. The author confirms this, but shows that the reaction is not conclusive, since earth-nut and cotton-seed oils give a similar coloration.0 ther colour reactions are also inconclusive. I n Becchi's test; the commercial oil causes a slight reduction, but the fatty acids cause no reduction. I n the author's opinion the best tests for curcas oil in olive oil are the characteristic odour, and the increase in the specific gravity, refractive index, and iodine value. The oil was found to contain 9.59 per cent. of solid fatty acids melting at 57.5" C., and with a molecular equivalent of 269.5, from which data they were judged to consist of 20 per cent. of stearic and 80 per cent. of palmatic acid. No myristic acid could be detected. The liquid fatty acids (80 per cent.), separated as lead salts with ether, yielded on oxidation by Hazura's method equal quantities of sativic and dihydroxy-stearic acid, from which it was concluded that they consisted of equal parts of oleic and linolic acids.No ricinoleic or linolenic acid was found. C. A. M. __ -__ _ _ _ _ ~ _ _ _ -. Oil of Paradise Nuts, Oil of Brazil Buts, Maize Oil. G. de Negri. (C'hcm Zeit., 1898, xxii., 961, 976.)-Paradise nuts are the seeds of the Lecythis sapucnin (xabucajo), a large tree belonging to the MyrtaceB found in Brazil and Guiana. The seeds are edible, having a pleasant taste resembling Brazil nuts. On extraction with petroleum ether, 50 to 51 per cent. of a clear, colourless, or faintly yellow oil is obtained, which quickly turns rancid, but not so fast as oil of Brazil nuts. The latter begins to solidify at 4" or 5", and is quite solid at 0" ; oil of paradise nuts yields a white deposit at 12O, and solidifies completely at 8"; It is soluble in ether and chloroform, insoluble in cold absolute alcohol, hardly soluble in hot water; it is insoluble in cold acetic acid, but dissolves in an equal volume of the hot acid.When maize is ground the germs are usually removed, and the yield is about 1 per cent. They show the following composition : water, 11.55 per cent. ; nitro- genous matter, 39.07 per cent. ; fat, 12.5 per cent. ; carbohydrates, 31.76 per cent. ; mineral matter, 5.3 per cent. On extraction with petroleum spirit 8 per cent. of oil is obtained, which is clear, yellowish-brown, and possesses a characteristic odour. I t solidifies at 15" to a yellow crystalline mass.I t is soluble in ether, chloroform, and carbon disulphide, insoluble in cold absolute alcohol, soluble in 30 parts of hot spirit. It saponifies slowly with alcoholic,'potash. Maize oil quickly becomes rancid ; one sample kept for a year in a half-filled flask finally coritained 43-86 per cent. of free (oleic) acid. According to their place of origin, the germs differ widely in composition; one specimen of oil remained liquid at 0" for several hours ; the iodine and acid numbers also vary. I t s colour reactions are : Haydereich, orange-yellow with violef spots ; BrullB, black, afterwards blood-red, solid in twenty-four hours ; Schneider, no colour ; Becchi, very faint brown; Milliau, faint brown ; Baudoin, no colour. On distilling maize, a residue containing 11 per cent.of solid matter and 5.5 per cent. of oil is recovered (Villon). Maize itself yields 0.5 per cent. of oil, rather darker in colour than that obtained from the embryos. At 65" it dissolves in an equal volume of glacial acetic acid. The constants of these three oils are :16 THE ANALYST. Oil of Oil of Maize Oil. Brazil Nuts. Paradise Nuts. Specific gravity . . . ... ... 0.918 0.895 0.9245 Saponification number . . . ... 193.36 173.63 182.81 Iodine number . . . ... ... 106-22 71.64 115.17 Acid number (calculated as oleic) . , . 1.433 3-19 5.65 Solidifying point of fatty acids ... - 28.5" 29.7" Iodine number of fatty acids ... 106.04 72.33 123.27 Refractometer number at 15" (Zeiss- Solidifying point . . . ... . . I 0" 4" 15" ... - 44.08 c Acetyl number .. . I.. Melting point of fatty acids . . . 28"-30" 37.6" 39-5" Wollny) ... ... ... ... - 61 -3-6 1 -5 74.5 F. H. L. [Oil of paradise nuts must not be confused with oil of grains of paradise. Grains of paradise, guinea grains, or Melegueta pepper (Semina cardanzovzi majoris) are the seeds of Amomurn meleguetn, an African plant of the ginger species, This oil is volatile (cf. ANALYST, 1898, xxiii., 12). Paradise nute are also known as sapucaia nuts, or '' monkey pots."-F. H. L.] Henriques' Process for the Analysis of Indiarubber Articles. R. Thal. (Chenz. Zeit., 1898, xxii., 974.)-This process (Chem. Zeit., 1892, xvi., 1644) consists, i?zter d i n , in a separation of the true rubber from rubber substitutes by the action of boiling S per cent. alcoholic soda, filtering off the dissolved matter through paper to avoid contamination of the solution with particles of loosened loading material, etc.Thal observes that an error is introduced into the operation by the partial solubility of filter-paper in the reagent; and he finds that Schleicher and Schull's extracted papers '' No. 589," previously dried to constant weight at 100" C., lose between 4.86 and 6.88 (mean 5.63) per cent. of their weight when 100 C.C. of 8 per cent. alcoholic soda and the necessary amount of water to reniove alkalinity pass through them. Rubber goods which are not loaded and only lightly dusted with talc need not be actually filtered to separate the soluble from the insoluble portion ; but loaded articles must be filtered for the reasons just mentioned. He suggests, therefore, that the '' No.589 " papers 12.5 cm. in diameter be always employed, and that 5.5 per cent. of their weight be added to the extracted rubber residue as a correction for solubility ; taking 4 grammes of the sample for analysis, this loss, if not allowed for, would lead to a deficit of about 1-42 per cent. in the residue calculated on the crude material. F. H. L. Vanillin Mixed with Acetanilide. R. Hefelmann. (Apoth. Zed., 1898, No. 49 ; through Deutsche Chem. Zeit., 1898, xiii., 358.)-In this product (which has already been referred to, ANALYST, 1898, xxiii., 266) the acetanilide was detected by a nitrogen estimation. The adulterated vanillin began to melt at 61", instead of between 79" and 82". I t was only partially soluble in dilute caustic soda, whereas it should have been easily and completely soluble, To isolate the impurity, an ethereal solution was repeatedly extracted with strong sodium bisulphite, when the vanillin passed entirely into the aqueous liquid in combination with the bisulphite ; the ether was washed in a little water and evaporated. The residue exhibited the correct crystalline form, melted at 111" to 113", yielded drops of aniline on warming withTHE ANALYST. 17 concentrated potash, and gave a strong odour of isonitrile on addition of chloroform to the alkaline liquid. Acetic acid was also to be recognised by the ordinary tests. F. H. L.