RESEARCHES ON THE VOLATILE HYDROCARBONS. 147 



ducted more rapidly. Distillation began at 138°.G, and termin tod at 139*, having 

 distilled almost to dryness. The time occupied was seventeen minutes. Taking the 

 average of these observations, viz. 138°.4, and applying the 00 -torn a ry corrections \\ 

 find 139\8 to be the corrected boiling-point of xylole. 



Analysis. — 0.1333 gramme of xylole gave, by combustion in a stream <>f o\\ 

 gas, 0.4413 of carbonic acid, and 0.1185 of water. 



Calculated. Found. 



Carbon, C 16 96 90.57 9< 29 



Hydrogen, II 10 10 9.43 9.87 



106 100.00 10...16 



Determination of Vapor Density. 



Temperature of balance, 

 Temperature of oil bath, 



1 6°. 5 



207°.5 



Height of barometer, .... 760 mm - at 14° 



Increment of balloon, 0.3528 



Capacity of balloon, . * .. .. ► . 228 c. c. 



Density of vapor found, . . . 3.7517 



Theory C 16 H 10 , .. ... . . 3.6665 



These results show clearly that this body has the formula C 16 H 10 , and that it is 

 doubtless the third member of the benzole series* Although xylole, first discov- 

 ered by Cahours in the oil separated from wood-spirit, has had a much lower boiling 

 point assigned to it, I have retained that name for this body, since the results which I 

 have obtained in the study of the light oil from wood-tar indicate that when the cor 

 responding body from this source is in a state of equal purity, its boiling-point will 

 agree with the above determination. I may here mention that in my researches on 

 the light oil from wood-tar, I have obtained a body at about 140°, but nothing between 

 that and 110° (these temperatures are not corrected), although special pains 

 taken to work up the intermediate fractions. So that I am in a position to justify 



were 



* As this memoir is passing through the press, the receipt of my journals for September calls attention 



late publication 



hydrocarbon. Muller conclud that 



it is xylole, a result which agrees with my own. (Annahn der Chemie und Pharroacie, 



erroneously regards it as being a new hydrocarbon, not belonging 



aeries. (1 ', 



new hydrocarbon, and 



Q» iiu* (i* 



• 



