EXAMINATION OF A NAPHTHA FROM LIME-SOAP. 179 
Of the crude oil in question, ten separate portions, each measuring 6000 ¢. ¢. were 
distilled from a copper retort through the hot condenser, as described in the cited Me- 
moir. The oil began to boil in the retort at about 140° C. and the first portions of dis- 
tillate passed through the hot condenser when this had risen to about 120°; the 
temperature of the oil in the retort gradually rising to 250° or more, and that of the 
hot condenser to 220°, at which point the process was interrupted, and the residue in 
the retort thrown aside. During this first distillation the temperature of the hot con- 
denser-was maintained on the average from 30° to 50° below that of the bvuiling liquid 
in the retort. The total amount of distillate, that is, of naphtha, obtained was equal to 
about 20 % of the crude oil; by far the larger portion of the latter being composed of 
difficultly volatile substances incapable of distilling over at 220°. The naphtha is a mo- 
bile liquid, of light, lemon-yellow color, and peculiarly nauseous odor. As in the 
crude oil, so here the odor of acetone is noticed among others. But in this connection 
it will be well to remark that by far the larger portion of the naphtha appears to con- 
sist of hydro-carbon oils, the oxygenated compounds, like acetone, &c., which have 
been noticed by previous observers, being present in altogether subordinate propor- 
tion, and merely as impurities, as it were, or contaminations. 
This first distillate or naphtha was now repeatedly redistilled,on an average 
about seventy-five times,— from glass retorts through hot condensers as before, until 
portions of constant or nearly constant boiling points were obtained; and until the 
quantities of material lying between these “heaps” or fixed points had become so 
small as to leave no doubt of the absence of other bodies. During the progress of 
these operations, which lasted nearly a year, the more offensive element of the odor of 
the hydro-carbons, and the odor of acetone also, gradually disappeared in great meas- 
ure; the yellowish color of the first products also diminished as the work went on, all 
of the pure hydro-carbons finally obtained being perfectly colorless. Considerable 
amounts of solid matter also collected in the retorts, especially during the distillation 
of the bodies of higher boiling points, being formed most probably from the oxidation 
of impurities with which the crude hydro-carbons were contaminated. 
When the process of distillation was completed it appeared that at least sixteen 
bodies of constant boiling points had been obtained. But up to that time not the 
slightest clew to the composition of any of these bodies had been observed. So far as 
had been noticed their odor was unlike that of any bodies with which we were 
familiar, while the action which some of them had been found to exert upon sodium 
indicated the presence of substances very different from the hydro-carbons which had 
previously fallen under our notice. 
