590 PROCEEDINGS OF THE AMERICAN ACADEMY. 



was cooled to 0°, filtered at the same temperature, and the filtrate 

 cooled to — 10° and filtered under pressure at the same temperature. 

 The three solids were carefully purified by crystallization from ether 

 and alcohol and their melting points taken. The solid separated at 

 ordinary temperatures melted at 48°, that separated at 6° melted at 

 51°-52°, and that separated at —10° melted at 51°-52°. 



It is therefore evident that this distillate consists chiefly of one solid 

 hydrocarbon, Co 4 H 50 i and that the oil remaining liquid at —10° belongs 

 to a different series. 



Pentacosane, C 25 H 5 2, and Liquid Hydrocarbon, C 26 H 52 . 

 From Distillate 280°-282°, 50 mm. 



After the fifteenth distillation, 100 grams collected at 280°-282°, 

 50 mm., which deposited a larger quantity of solid hydrocarbon than the 

 lower distillates. This solid was separated from the oil and the latter 

 was then cooled to 0° and filtered at the same temperature. 



The specific gravity of the filtered oil at 20° was 0.8580. 



A combustion gave the following values : — 



0.1593 grm. of the oil gave 0.4997 grm. C0 2 and 0.2107 grm. H 2 0. 



Calculated for C^Hjj. Found. 



C 85.70 85.55 



H 14.30 14.67 



The formula was established by its molecular weight, determined at 

 the boiling point of benzol: — 



3.9867 grms. of the oil and 30.19 grms. benzol gave a rise of 0°.936. 



Calculated for C^H^. Found. 



364 362 



A determination of the index of refraction gave 1.4725, which cor- 

 responded to the molecular refraction : — 



Calculated for C 26 H 52 . Found. 



119.87 119.12 



After crystallization from ether and alcohol, from which it separated 

 in crystalline plates, the solid hydrocarbon gave percentages of carbon 

 and hydrogen required for the series C n H 2n+2 . 



