C. M. Warren on the Volatile Hydrocarbons. 97 
was to insure the detection of any-constituent which might be 
present in small proportion, The process of fractioning was 
continued on this large scale until the separations o far 
variation of more than one or two degrees of the thermometer. 
Finally, a sample gallon was taken from each of the barrels com- 
posing the last series of products, and these samples were set 
aside for this investigation, which was afterwards conducted in 
the laboratory. : 
Of the Results of Fractional Condensation —Such of the sam- 
ples above mentioned as promised to yield the different constit- 
uents of the naphtha in the largest proportion were subjecte 
to repeated series of fractionings by my process of “‘ Fractional 
Condensation.” Ag full details of this process have already 
been given in the memoir referred to, it will be needless to re- 
peat them here. It will suffice to say that the fractioning in 
this case was conducted in all respects as there described, and 
continued until the whole of the naphtha taken, boiling between 
80° and 170°, had accumulated at the four points already indi- 
cated, viz: at 80°, 110°, 140°, and 170°; or so nearly the whole 
that the intermediate quantities had become too small to admit 
of being further operated upon. Having, therefore, so thor- 
oughly exhausted the intermediate fractions, I can have no hesi- 
tation in asserting that no other body than those alluded to was 
resent in the naphtha,—at least, in appreciable quantity,— 
nee, that the parabenzole of Church was probably only a mix- 
ture of benzole and toluole. I may here remark that each of 
the sample-gallons employed, when subjected to my process of 
fractioning, was found to contain, in variable proportion, all of 
=) 
the constituents of the naphtha. 
Of some of the Properties of the Bodies obtained by Fractioning.— 
1. BenzoLe.—Specific gravity, 0°8957 at 0°, and 0°882 at 15°°5.* 
"™ Memoirs of the American Academy, 1864, and last volume of this Journal, 
ah SS Id appear that the specific gravities of liquids are usually determined 
at the temperature of the air. ‘The result of this is that the determinations made 
by different observers are not comparable with one another. these specific 
