38 PROCEEDINGS OF THE AMERICAN ACADEMY. 



the solution no crystalline product appeared until the solution was so 

 far concentrated that the sodic metaxylol sulphonate was deposited. 

 Orthoxylol cannot therefore be present in any appreciable quantity. 



Determinations of the constituents capable of forming nitro products 

 were also made in the fractions containing the xylols by treatment 

 with a mixture of nitric and suphuric acids according to the method 

 employed for benzol and toluol. The quantity of xylol corresponding 

 to the nitro product represented by the portion not affected by nitric 

 acid in the fraction 137°-138° was 54.3 per cent of the weight of oil 

 taken; in the fraction 139°-140°, 72.1 per cent; and in fraction 

 141°-143°, 31.5 per cent. Calculating the percentages of xylols from 

 the results of the first determination in the 41.5 kilos of crude oil first 

 distilled, the quantity of metaxylol is 0.016 per cent, and of paraxylol, 

 0.013 per cent. Evidently the xylols were not wholly collected in 

 their respective fractions, although the quantity outside of the limits, 

 137°-143° was doubtless small. Probably at least one third should be 

 added to these results. But if the percentages were increased to the 

 results obtained by the action of concentrated nitric acid, the quantities 

 of the xylols in the crude oil would still be small. In the fractions 132°- 

 136° we observed the presence of aromatic hydrocarbons, although in 

 too small amounts for identification ; nitro products were formed by the 

 action of nitric acid. Attempts were made to ascertain the presence of 

 ethylbenzol and hexahydromesitylene, but vv'itliout success, on account 

 of the limited quantity of the distillates. After treatment of the frac- 

 tion 135°-136° with concentrated nitric acid to convert the hydrocar- 

 bons C„H2„_g into nitro products, and distilling off the hydrocarbons 

 not affected by the acid, the distillate was heated for some time with a 

 mixture of nitric and sulphuric acids. According to Baever,* fuming 

 nitric acid readily converts hexahydromesitylene into trinitromesity- 

 lene; but KonowalotFt found that a mixture of nitric and sulphuric 

 acids, or fuming nitric acid, forms the trinitro compound only very 

 slowly. After prolonged heating we obtained a crystalline nitro com- 

 pound, but in such small quantity that it was impossible further to 

 identify it. A much larger supply of these distillates will be necessary 

 to determine the presence of these bodies. 



* Ann. Cliem. Pharra., CLV. 275. 



t Ber. der deutsch. chem. Gesellsch., 1887, p. 1850. 



