102 PROCEEDINGS OF THE AMERICAN ACADEMY. 



required for butane. Ronalds also collected an oil between 6° and 8°, 

 specific gravity 0.6004, vapor density 2.178, which he regarded as a 

 mixture of butane with higher constituents. As will be shown in this 

 fjaper, nothing further has been done toward verifying the pentane from 

 which the peutyl chloride of Pelouze and Cahours was obtained, although 

 it was really derived from the pentane boiling at 30°, as we have ascer- 

 tained after many trials. 



Probably on account of difficulty in procuring an adequate supply of 

 material, Warren* gave less attention to the butanes than to the higher 

 constituents. He collected a distillate at 0°, which, on the basis of Ronald's 

 determination, he assumed was a butane. After repeated and careful 

 distillation through his regulated condenser, Warren also separated a 

 liquid, boiling point 8°-9°. Although nothing further was done towards 

 determining its composition, Warren believed this body " to have been 

 sufficiently purified to justify the conclusion supported by analogy that 

 there is a constituent boiling at about 8°-9°." Since no other attempts 

 have been made to identify the butanes, further study of these bodies was 

 evidently necessary. 



In returning to this subject, we assumed at first that it would only be 

 necessary to enforce the results already obtained, which seemed to be 

 supported by our first determinations. f But as the work progressed, it 

 soon became evident that this assumption would not be justified. Taking 

 advantage of the extremely cold weather in January, 1895, through the 

 kindness of Messrs. Schofield, Shirmer, and Teagle, we procured 45 

 litres of a second distillate of the naphtha from Pennsylvania and Ohio 

 petroleum, the most volatile portion that could be condensed with the 

 atmospheric temperature below 0°F. Since the naphthas from Pennsyl- 

 vania and Ohio petroleum are re-distilled together, it is difficult to pro- 

 cure this portion from either crude oil, unless, indeed, a run of the crude 

 oil were made in the refinery with this object in view. But this did not 

 seem necessary, since there can be little doubt that the constituents of the 

 most volatile portion of Ohio and Pennsylvania petroleums are identical. 

 During the continued cold weather of January, February, and March of 

 the same year, distillation of this product was continued through a Warren 

 condenser, filled with a freezing mixture, and the temperature of the dis- 

 tillates was kept very low to avoid loss so far as possible. In this manner 

 a long series of distillations was carried on with small loss, aside from 

 transference, except of the most volatile distillates. In these volatile 



* Proc. Amer. Acad., XXVII. 56. t Ibid., XXXI. 23. 



