RESEARCHES ON THE VOLATILE HYDROCARBONS. 145 
Distillation therefore occupied one hour and ten minutes, during which time the 
thermometer rose only 0°.6, being fifty minutes in rising 0°.2 from 79°.4 to 79°.6, at 
which temperature it had distilled nearly to dryness. Height of the barometer during 
the experiment reduced to 0°= 761.9™ Taking 79°4, this being the average of the 
last five observations, and applying the corrections for the upper column of mercury, 
and for atmospheric pressure, according to the directions given by Kopp,* we find the 
corrected boiling-point of benzole to be 80°.1. 
Analysis. — 0.2339 gramme of benzole gave, by my process} of combustion in a 
stream of oxygen gas, 0.7903 of carbonic acid, and 0.1683 of water. 
Calculated. Found. 
_—_—____elOCOCoCOoOoOCOCOCC 
Carbon, Cy 72 92.31 92.15 
Hydrogen, Hg 6 7.69 7.99 
78 100.00 100.14 
Determination of Vapor Density. — 
Temperature of balance, 7 : ‘ * is : 15° 
Temperature of oil bath, . : ‘ a . : 171° 
Height of barometer, . é ‘ : : 764.1™™ at 9° 
Increment of balloon, : < ‘ . : 0.2447 
Capacity of balloon, . ; : a 265 ¢. e. 
Density of vapor found, . - : - 2,688 
Theory C,, H; = 4 volumes, . : 2.698 
2. To.vo.e. 
Specific gravity, 0.8824 at 0°, and 0.872 at 15. 
Determination of Boiling-point. — The preparation employed for this determination had 
also been repeatedly boiled with sodium until the latter ceased to have any action 
upon it. Operating in this case also upon a pretty large quantity, the distillation 
occupied about an hour. The experiment was conducted as detailed under the head 
of Benzole. Distillation commenced at 110°.6; two minutes later the temperature 
had fallen to 110.4, at which point it remained absolutely constant during the lapse of 
forty-eight minutes. Five minutes later the temperature had risen again to 110°6; 
* Poggendorff’s Annalen, 1847, LX XII. 38. 
{ Proceedings of the American Academy, 1864, p. 251. 
VOL. IX. 23 
