108 PKOCEEDINGS OP THE AMERICAN ACADEMY. 



fact, beside the investigations within recent years in this laboratory lead- 

 ing to a better knowledge of the various series of hydrocarbons with high 

 boiling points, no attempts have been made to discover the true composi- 

 tion of American petroleum. In fractions below 200° from Galician oil, 

 Lachowicz obtained no reaction with bromine, yet so far as they have 

 been examined in this laboratory, distillates below 200° from American" 

 oils do not fail to show a considerable bromine absorption. The sulphur 

 compounds in Ohio and Canadian oils have a great affinity for bromine. 

 Substitution may take place in the aromatic hydrocarbons which Ameri- 

 can oils contain, as well as in the hydrocarbons C n H 2n+2 , unless light is 

 excluded. All these bodies, and probably others, are affected in the ordi- 

 nary determinations of bromine absorption. 



At the suggestion of one of us (C. F. M.), in connection with another 

 line of work on petroleum, Mr. T. A. Hicks, a student in this laboratory, 

 undertook a study of bromine absorption in crude oil and in fractions ob- 

 tained from it after various modes of treatment. Two determinations in 

 the oil before treatment gave as the percentage of bromine absorbed, (I), 

 8.43, and (II), 8.73. A portion agitated with alcoholic mercuric chloride, 

 washed and dried, gave (I), 9.27, and (II), 9.38, indicating that the crude oil 

 holds in solution to some extent the mercuric chloride compound. After 

 treatment with mercuric chloride, a portion of the oil shaken with common 

 concentrated sulphuric acid gave with bromine, (I), 5.91, and (II), 5.94. 

 The oil was next shaken with fuming sulphuric acid, washed, and dried, 

 when it absorbed bromine equivalent to (I), 3.47, and (II), 3.72. A por- 

 tion of the oil after the last treatment was distilled under atmospheric 

 pressure, fractions collected at 100°-125°, 125°-200°, and 200°-230°. 

 In the first distillate the bromine absorption was, (I), 4.65, (II), 4.75, in 

 the second, (I), 4.G3, (II), 4.58, and in the third, (I), 5.61, (II), 5.17 

 per cent. Another portion of the treated oil was distilled in vacuo under 

 50 mm., collecting at 130°-160°, 160°-190°, 190-260°, and a residue, 

 and bromine absorption determined. Bromine absorption gave in the 

 first distillate, (I), 1.73, (II), 2.00; in the second, (I), 1.96, (II), 2.01; 

 in the third, (I), 3.28, (II), 3.15, and in the residue, 9.52. From these 

 results it is evident that substitution in the less volatile portions of the 

 crude oil or cracking has much to do with the amount of bromine ab- 

 sorbed, especially since in these experiments the reagents employed for 

 the removal of the sulphur compounds should also remove unsaturated 

 hydrocarbons. In this connection Mr. Hicks determined bromine absorp- 

 tion in some distillates from Pennsylvania, Ohio, and Canadian oils, that 

 had been especially purified by long distillation and treatment with rea- 





