TABLE XVI.-PRODUCTS FROM THE CRUDE PETROLEUM OF SUMATRA

Künkler1 has published the results of the examination of various descriptions of lubricating oil, employed for the particular purposes specified (see Table XVII., folding sheet).

The specific gravity of Russian kerosene is higher than that of ordinary American kerosene, and still higher than that of American "water-white oil," but the Russian oil has greater power than the ordinary American oil of ascending a lamp-wick by capillary attraction, and affords in most lamps a better-sustained, though smaller and less brilliant flame than the latter oil. The relative capillary powers of three descriptions of kerosene, as determined by noting the quantity of oil withdrawn by ordinary lamp-wicks in a given time, from vessels of the same size, is shown by the following results obtained in the author's laboratory :

The viscosity of petroleum products increases with the density, but oils of the same specific gravity from different localities frequently differ in viscosity. This is especially noticeable in comparing the Russian and American oils, which are so widely different in chemical composition. Table XIX. shows the relative viscosity of water and various oils, as determined by the author.

Table XX. records results yielded, in the author's laboratory, by lubricating oils manufactured by the Burmah Oil Company from the petroleum of Yenangyaung, in Upper Burma.

The colour of the first sample (3) by Lovibond's tintometer, in a 2-inch cell, series 500, was 130; and of the second sample (4) was 224.

1 Dingler's polytech. Journ. (1889), cclxxiv., 280.

TABLE XIX.-VISCOSITY-SECONDS FOR 50 c.c.
Results obtained with Redwood's Standard Viscometer.

TABLE XX.-PROPERTIES OF BURMA LUBRICATING OILS.

PHYSICAL PROPERTIES OF COMMERCIAL PRODUCTS. 203

Höfer gives the following particulars of some of the commercial products of the distillation of petroleum :

TABLE XXI.-PHYSICAL PROPERTIES OF COMMERCIAL PRODUCTS
FROM PETROLEUM.

According to Veith, the American petroleum ether of commerce has a specific gravity of 0.63 to 0.65, while that obtained from Galician oil has a specific gravity of 0.65 to 0.66. Evers states that certain oils obtained during the compression of oil gas, and known technically as "hydrocarbon," are sold as petroleum ether. The "benzin" of the United States Pharmacopoeia is the portion of the distillate from American petroleum having a specific gravity between 0.670 and 0.675, and boiling between 50° and 60° C. The "petroleum-benzin" of the German Pharmacopoeia consists of the colourless, non-fluorescent portions of petroleum, having a specific gravity of 0.640 to 0-670, and distilling almost entirely between 55° and 75° C. Petroleum naphtha is required by the New York Produce Exchange to be "water-white and sweet," and of density from 68° to 70° Baumé (specific gravity 0·707 to 0.690). The oil which distils between the illuminating and lubricating oils is not much used, except as fuel and for the manufacture of oil gas. Further information respecting the various products of petroleum met with in commerce, will be found in the section dealing with the refining of petroleum.

1 Das Erdöl, &c. Bolley's Chemische Technologie, 1892, 369.

Chemical Properties. As regards its ultimate composition, petroleum consists essentially of carbon and hydrogen, together with oxygen, and usually with widely-varying amounts of nitrogen and sulphur. From the results of a large number of analyses by M. Deville1 and others, the carbon appears to vary between 79.5, as given by Deville for an oil from Schwabweiler, in Alsace, having a specific gravity of 0.829, and containing 13.6 per cent. of hydrogen; and 88-7 according to Boussingault, also for petroleum from Schwabweiler. The hydrogen apparently varies between 9-6, on the authority of Deville, for an oil from Pechelbronn, in Alsace, and 14.8, also according to Deville, for an oil from Oil Creek, Pennsylvania. Professor Peckham gives the following as the composition of specimens from districts in the United States:

M. Delesse found 0.154 per cent. of nitrogen in elaterite, and 0-256 per cent. in the asphalt of Trinidad. Mr. Beilby2 states that he found in crude American petroleum, at least 0.008 per cent. of nitrogen, in crude Galician, 0.188 per cent., and in crude Baku petroleum, 0·05. He states that the nitrogen is present as bases which are removable by sulphuric acid, and that it tends to accumulate in the residues from the distillation. Wellers has found alkaloid-like bases in the petroleum of Saxony, and Baudrowski has ascertained the presence of similar bodies in Galician oil.

In a paper on the nitrogen content of California bitumen, read at the Congress of Chemists at San Francisco, June 9, 1894,5 Peckham refers to a case which came under his observation many years ago, in which a quantity of petroleum, estimated at 2 quarts, contained in a small cavity in the rock, "was so filled with maggots that they crawled over each other precisely as they would in a pool of blood," and he gives the results of some recent investigations, showing that this description of petroleum contains basic oils combined with an exceedingly viscous, feebly-acid tar. To the presence of these bodies, the difficulty which had been experienced in refining the oils was found to be due, and it is stated that the discovery has led to very important

1 Comptes Rendus, lxvi., 442; lxviii., 485, and lxix., 1007.

2 Journ. Soc. Chem. Ind., 1891, 120.

3 Berichte d d. Chem. Gesellschaft, xx., 2098.

5 Am. Journ. Sci., xlviii., 1894.

4

Loc. cit.