RESEARCHES ON THE VOLATILE HYDROCARBONS. 147 
ducted more rapidly. Distillation began at 138°.6, and terminated 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 customary corrections, we 
find 139°.8 to be the corrected boiling-point of xylole. 
Analysis. — 0.1333 gramme of xylole gave, by combustion in a stream of oxygen 
gas, 0.4413 of carbonic acid, and 0.1185 of water. 
Calculated. Found. 
Peeesnee ane ee 
Carbon, Cys 96 90.57 90.29 
Hydrogen, Hy 10 9.43 9.87 
106 100.00 100.16 
Determination of Vapor Density. — 
Temperature of balance, . . & ; ‘ ‘ 16°.5 
Temperature of oil bath, < : ‘ 3 207°.5 
Height of barometer, - ‘ : : 760™™ at 14° 
Increment of balloon, é i 3 : - 0.3528 
Capacity of balloon, . ‘ . ‘ . : 228 c. c. 
Density of vapor found, . * - 8.7517 
Theory Cy Hy, . ‘ ‘ : . 8.6665 
These results show clearly that this body has the formula C,, Hy, 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 were 
taken to work up the intermediate fractions. So that I am in a position to justify 
* As this memoir is passing through the press, the receipt of my journals for September calls attention to 
late publications of Hugo Miiller, Béchamp, and Naquet concerning this hydrocarbon. Miiller concludes that 
it is xylole, a result which agrees with my own. (Annalen der Chemie und Pharmacie, 1864, CKXXI. 321.) 
Béchamp, on the contrary, erroneously regards it as being a new hydrocarbon, not belonging to the benzole 
series. (Bulletin de la Société Chimique, Paris, 1864, 204.) Naquet also calls it a new hydrocarbon, and 
gives it the formula Cig H,,. (Bulletin de la Société Chimique, Paris, 1864, 205.) 
