RESEARCHES ON THE VOLATILE HYDROCARBONS. 



145 



D 



therefore occupied one hour and ten minutes, during which time the 



only 0°.6, being fifty minutes 



thermometer rose 



which temperature it had distilled nearly to d 



ring 0°.2 from 79".4 to 79°.6, at 

 Height of the barometer during 



the experiment reduced 







761.9 



mm. 



five observations, and applying the 



Taking 79\4, this being the average of the 

 rrections for the upper column of mercury, 



> 



and for atmospheric pressure, according to the directions given by Kopp,* we find 

 corrected boiling-point of benzole to be 80°. 1. 



Analysis. — 0.2339 gramme of benzole gave, by my process f of combustion in a 

 stream of oxygen gas, 0.7903 of carbonic acid, and 0.1683 of water. 



Carb 



on 



Hydrogen, 



C 



\i 



H 



6 



Calculated. 



Ato 



72 

 6 



78 



92.31 

 7.69 



100.00 



Found. 



92.15 

 7.99 



100.14 



Determination of Vapor Density. 



Temperature of balance, 

 Temperature of oil bath, 

 Height of barometer, 

 Increment of balloon, 

 Capacity of balloon, 



Theory C 12 H ( 



4 volumes, 



764.1 



mm. 



15' 

 171' 



at 9 



0.2447 

 265 c. c. 



Density of yapor found, ... . . 2.688 



2.698 



2. TOLUOLE. 



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 



any 



upon 



occupied about 



Operating in this 



upon a pretty 



quantity, the d 



ho 



ur. 



The experiment was conducted as detailed under the head 



of Benzol 



Distillat 



commenced 



110\6 



two minutes later the temperatu 



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 U0°.6 ; 



* PoggendorfTs Annalen, 1847, LXXII. 38. 



t Proceedings of the American Academy, 1864, p. 251 



VOL. IX, 



2S 



