MABERY AND HUDSON. — AMERICAN PETROLEUM. Ill 



0.1680 gram of the oil gave 80.6 c.c. of vapor at 182°, and under a 

 teiisiou of 426 lutu. 



Calculated for C5H10CI,. Found. 



4.88 4.78 



The boiling point of this diclilorpentane is the same as that of amylene 

 chloride, 145°, described by Bauer.* It is to be regretted that the quan- 

 tity of our [n-oduct was so limited ; but on account of the great amount 

 of labor involved in its preparation, it did not seem advisable to attempt 

 the preparation of a larger amount. 



These results indicate that petroleum contains but one butane, and that 

 is isobutane, whii-h collects at 0°. That this body is not normal butane 

 is shown by tlie boiling point, 67°-68°, of the monochlor derivative, the 

 boiling point, 116°, of the acetate, that of the alcohol, 108°-109°, and 

 that of the sul[)hide, 172°, It has hitherto been assumed that the butane 

 in petroleum is the normal hydrocarbon, because the butane prepared by 

 Frankland from ethyl iodide and zinc boils at 0°. But isobutane pre- 

 pared by Butlerow from tertiary butyl alcohol should boil at — 17.°o. 

 The differences between the properties of butane and isobutane are suffi- 

 ciently marked to permit, without difficulty, of distinguishing between the 

 isomeric forms. 



Normal butyl chloride boils at 77°. j6, and the alcohol at 117°. Since 

 our series of derivatives from petroleum butane was prepared several 

 times with the same results, and never with the formation of compounds 

 with boiling points corresponding to normal butane, there can be no ques- 

 tion that normal butane is not contained in Pennsylvania nor in Ohio 

 petroleum. The serious question concerns the boiling point of isobutane 

 which we found in petroleum. As has been fully explained, our 0° 

 fractions were separated as many as four different times from the lightest 

 gasoline we could procure from the refinery. While we never failed to 

 collect distillates below — 10°, they were much smaller in quantity than 

 those in the vicinity of 0°. It is, therefore, certain that the butane we 

 had in hand was isobutane, and it seems equally certain that this hydro- 

 carbon collected at 0° and not at —17°. 



The Octanes in Ohio Petroleum. 



It has already been pointed out by one of us (C. F. M., he. cit.) 

 that the published accounts of the octanes in petroleum are not fully 



* Zeit. fiir Chem., 1866, p. 380. 



