MARCH, 1905. Vol. XXX., No. 348. NOTE ON COMMERCIAL AMYL ALCOHOL. BY H. DROOP RICHRXOND, F.I.C., ARD J. A. GOODSON. (Read at the Meetiiag, December 7, 1904.) A CONSIGNMENT of amyl alcohol was found to give, when used in the Gerber method of fat estimation, constantly high results. With milks the average reading was 0.10 per cent. higher than gravimetric estimations, and with separated milks (con- taining about 0.1 per cent. of fat) 0.06 per cent. higher. This amyl alcohol complied with the specification laid down by one of us in conjunction with F. R. O'Shaugh- nessy, and when 1 C.C. was treated with 11 C.C. of water and 10 C.C. of sulphuric acid, only the faintest indication of an insoluble layer was seen on the surface. Various mixtures of amyl alcohol acid and water were made, and the layer read off in a Gerber bottle as if it were fat.1 C.C. amyl alcohol, 11 C.C. of water, and 10 C.C. of acid yielded trace. 2 7 , P , 10 $ 7 7 7 10 Y f ,, 0.12 3 9 9 2 ) 9.5 7 , 7 , 9.5 , Y ,) 0.04 4 , Y ? Y 9 I f 9 , 9 9 ) ,, trace. 5 , Y 9 8 8.5 f ? 7 , 8.5 ,, 9 , none.78 THE ANALYST. The impurity in this alcohol was soluble in the acid mixture, and the solubility 250 C.C. were distilled through a fractionating column : 124.5" to 127.5" 7 , 32 9 ) 127.5" to 128.5" 7, 36 9 ) 128.5" to 129.5" 7 2 62.5 ,, 129.5" to 130.5" 9 , 73 1 , 130.5' to 131.5" 9 7 18.5 ,, Leaving a residue of increased with the amount of amyl alcohol. 94" to 124.5" (corrected). 16 c.c distilled. 10 C.C. When 2 C.C. of each fraction were treated with 10 C.C. of water and 10 C.C.of sulphuric acid, no layer was observed to rise; but 2 C.C. of the residue gave a layer measuring 3.0, which had a smell of petroleum. The residue from the distillation of 500 C.C. was shaken with sulphuric acid, the layer separated, washed with water, caustic soda solution, and again with water, and dried with calcium chloride. This had a density of 0.803, and boiled at 190" to 230°, smelt of petroleum, and was slightly fluorescent. Mr. J. B. P. Harrison informs us that petroleum barrels are used as packages for &my1 alcohol, and that as much as 4 per cent. of petroleum has been observed. A milk which read 4-32 per cent. fat with the crude alcohol gave an average of 4-21 per cent. with various fractions of the distilled product, and a separated milk 0-17 per cent.with the crude and 0.12 per cent. with the distilled. Mixtures of amyl alcohol with varying amounts of petroleum were made : Iteadin~ with Percentage of Petroleum. 4-8 2.4 1-2 0.6 0.3 none Milk. 0.67 4.48 0.25 4.37 0-11 4.23 trace 4-19 doubtful trace 4.12 none 4.10 2 C.C. Alcohol, 10 C.C. Water, 10 C.C. Sulphuric Acid. Separated Milk. 0.48 0.25 0.16 0.12 0.09 0.09 We also found that the drying of the fat obtained by the method described by one of us with C. H. Rosier (ANALYST, 1899, xxiv., 172) took some hours before a constant weight could be obtained when this amyl alcohol was used. We conclude that : 1. The amyl alcohol in question contained about 1 per cent. of petroleum. 2. This quantity of petroleum is soluble in a mixture of the amount of amyl alcohol, sulphuric acid and water used in .the Gerber method, and is partially extracted by small amounts of fat (0.1 per cent.), and wholly by larger amounts.3. Amy1 alcohol which gives any visible insoluble layer when 2 C.C. are treated with 10 C.C. of water and 10 C.C. of sulphuric acid should not be used in the Gerber method; a blank Gerber test is insufficient. Van Haltrst (ANALYST, 1903, 213) and Siegfeld (ANALYST, 1904, 113) have stated that apparently pure amyl alcohol may give high results with Gerber's method, and it is probable that they were dealing with amyl alcohol containing small amounts of petroleum.THE ANALYST. 79 Tested according to specification : Specific gravity at 15.5" ... ... 0.8149 Distillation of 25 C.C. ... ... first drop at 125" C. 125 to 127-5 2-25 C.C. 127.5 to 130.5 91-25 C.C. 10 C.C. and 10 C.C. HCl ... clear colourless solution. 0.5 C.C. water produces turbidity. Final temperature . . . ... ... 131' Polarization Blank Gerber ... faint trace of layer. . . . 2.58" in 200-millimetre tube [ a ] , r= 1.61'. DISCUSSION. Mr. RICHMOND, in reply to a question put by the President, said that in the sample referred to the proportion of petroleum was, they had concluded, somewhere about 1 per cent. This conclusion was baeed, not only on the figures given, but also on the amount they had been able to separate by fractional distillation. He had, however, heard of a sample containing 4 per cent. of petroleum.