BUSHONG.] Chemical Composition of Petroleum. 307 
much as 5.21 per cent. They found that the products contain- 
ing oxygen were chiefly neutral, but partly of acid character. 
They isolated several acids, one of which proved to be identical 
with an acid found in Roumanian petroleum by Hell and Med- 
inger.25! Aschan”? later proved these acids to belong to a class 
to which he gave the name naphthene carboxylic acids, which 
have the general formula C»aHn-O>. 
These acids, which are formed in the crude oils as well as 
their products through contact with oxygen from the air, are 
capable of attacking metals, thereby dissolving them in appre- 
ciable amounts. They also dissolve sulfur readily. 
SULFUR COMPOUNDS IN PETROLEUM. 
Richardson and Wallace?** separated sulfur in the form of 
erystals from Beaumont oil. Thiele?°+ found 63.63 per cent. 
amorphous sulfur and 6.81 per cent. crystalline sulfur in the 
sediment in a tank-car which had contained Beaumont oil. 
Hydrogen sulfid is very generally emitted by oils that con- 
tain sulfur in considerable quantities; and its alkyl derivatives, 
methyl sulfid, ethyl sulfid and higher homologues of the series 
(CnHen1)2S have been found in Lima oil, while compounds of a 
series C2H»S, which appear to be cyclic in structure, have been 
found in Canadian petroleum.” 
NITROGEN COMPOUNDS IN PETROLEUM. 
California petroleum is specially rich in nitrogen bases of 
the pyridin or hydropyridin and chinolin type. Peckham?°° 
found more than one per cent. of nitrogen in several samples 
which he examined. Mabery found as much as two per cent. of 
nitrogen in other samples, and estimates from this that the 
basic nitrogen compounds make up 20 to 25 per cent. of the 
crude oil. Pennsylvania oils contain only traces of nitrogen. 
The Examination of Kansas Petroleum. 
At the present time no uniform methods for the examina- 
tion of petroleum have been generally adopted by chemists, but 
a committee for the unification of methods of testing petroleum 
251. Berichte d. deutsch. chem. Ges. 7, 1216; 1874, 10, 451; 1877. 
252. Berichte d. deutsch. chem. Ges. 28, 867; ’98; 24, 1864; ’94,; 25, 3661, ’95. 
253. Eng. Mining Jour. 73, 352; 1902. 
254. Chem. Zeit, 26, (77) 896, J. Soc. Chem. Ind. 1902, 1271. 
255. Proc. Amer. Acad. A. and S. 41, 89; 1905. 
256. Rept. Geol. Sur. Cal. 2, 89. Amer. Jour. of Sci. (3) 48, 250; 1894. 
