RESEARCHES ON THE VOLATILE HYDROCARBONS. 167 
2p Series.* 
Difference of Range of Tempera- 
Formula. (?) Boiling-point. cased boiling-point ee oe 
: distil. 
Cy Hy 8-9 : : 
oc 37.0 C, H, 29.0 0.4 
Coa, 68.5 C, H, 31.5 0.6 
cle 98.1 C, H, 29.6 1.2 
GH, 127.6 C, H, 29.5 1.5 
119.6 + 4= 29°.9 
Average increment of boiling-point for the addition of C, H, = 29°.9. 
8p Series. (ot completed.) 
Diffe f Range of Tempera- 
Formula. Boiling-point. Homenwsy boling-pint ba bine wis oe 
: distil. 
GH, 174.9 _ 1.7 
Cop Hog 195.8 C, H, 20.9 1.5 
Cy Hay 216.2 C, He 20.3 2.2 
41.2 + 2—= 20°.6 
Average increment of boiling-point for the addition of C, H, = 20°.6. 
2. Of the Hydrocarbons obtained from Albert Coal. 
Ist Srrres. (ot completed.) 
a Range of Tempera- 
Difference of yee A 
ae ws Elementary ai 4a ture within which the| 
Formula. Boiling-point. difference. poling zene substance would all 
© distil. 
° ° ° 
Cy His 
C,. Hu 59.9 C, H, 1.5 
Cus Hig 90.6 C, Hy 30.7 0.5 
Ca He 119.7 C, Hy 29.1 0.5 
59.8 -- 2 = 29°.9 
The average boiling-point difference, in this series, for the addition of 
C, H,, is, therefore, 29°.9. 
a quantity of liquid in the retort. Similar instances of absolute constancy of boiling-point as those just cited, 
might be given from among the products in either series from petroleum and Albert coal; which the ranges of 
temperature given in these tables do not indicate. 
* T am somewhat in doubt whether the bodies composing this series and the 2d Series from Albert coal 
have the formula C, H, +, as here represented, there being some indication that they contain less of hydrogen. 
For the purpose for which they are now presented, it is immaterial which formula is employed, as the common 
elementary difference and the boiling-point differences would remain the same; the solution of this question 
is therefore deferred for a subsequent memoir. 
