134 COMPOSITION OF AMERICAN PETROLEUM. [Feb 5, 



portions of the crude oil evidently invited further examination. 

 The most volatile distillates of Pelouze and Cahours gave with 

 chlorine a chlorbutyl boiling at 65°-7o°, but nothing further was 

 done toward identifying the hydrocarbon. Ronalds {London 

 Chem. Soc, 1865, p. 64) recognized a butane at 0°, but its form was 

 not determined. Warren collected a distillate at 0°, and another at 

 8°-9°, which he inferred from analogy was a butane, but no further 

 examination was made of these distillates. In our examination, 

 after very prolonged distillation, using freezing mixtures for conden- 

 sation, no distillate remained between 5° and 20°, thus excluding a 

 butane at 8°-9°. At 0°, a large quantity of a hydrocarbon was 

 obtained which gave a chlorbutane boiling at 67°-68°, the boiling 

 point of isobutyl chloride. By decomposition of the chloride with 

 alcoholic potassic acetate, an acetate was formed, and from the 

 acetate an alcohol was obtained boiling at io7°-io8°, which gave the 

 percentages of carbon and hydrogen required for isobutyl alcohol. 

 These facts, with the formation of isobutyl sulphide by treating the 

 chloride with alcohol potassic sulphide, indicate that the hydrocar- 

 bon collected at 0° was isobutane, but they do not accord with the 

 properties of butane and isobutane, the former of which, prepared 

 by Frankland from ethyl iodide, boils at 0°, and the latter, pre- 

 pared by Butlerow from tertiary butyl alcohol, boils at -17°. 

 Petroleum butane was prepared several different times from the 

 most volatile refinery distillates we could procure, and always with 

 the same results (Mabery and Hudson, Froc. Amer. Acad., xxxii, 

 1 01). In reviewing the octanes in petroleum, we found one boiling 

 at 1 1 9°. 5, confirming the statements of Warren, and another 

 boiling at 124°-! 25°, but no distillate remained above 125°. 

 From the results of my work recently published, and what I have 

 now in progress, it can, I think, be stated with confidence that 

 it is useless to attempt to separate the constituents of petroleum 

 boiling above 220^ by the ordinary process of distillation, and 

 whatever results have been published concerning distillates obtained 

 in this manner shed no light on the constituents of the crude oils. 

 Of course this is cold sympathy for those who desire to know more 

 of these higher portions, since there is only one method, fractional 

 distillation, for such separations, and this method can only be 

 applied without decomposition by excluding air and reducing the 

 boiling points. To illustrate its tediousness, early in October, two 

 assistants started a distillation of 125 liters of Pennsylvania crude 



