UTAH ACADEMY OF SCIENCES 93 
The thermometer bulb was placed opposite the dis- 
charge tube—not in the liquid hydrocarbon. The distillation 
continued until the sample carbonized. 
A number of distillations were made with reduced 
pressure. A brass retort was used for these as the glass 
could not stand the external pressure when hot. The re- 
sults were not satisfactory as we could not condense the 
distillate completely. Lack of time prevented further in- 
vestigation along this line and study of the distillates. It 
was found, however, that gilsonite is soluble in its distillates 
and in the distillates from wurtzellite and tabbyite. Tab- 
byite is soluble in the distillates from gilsonite and wurtz- 
ellite, but wurtzellite is insoluble in its own distillates or in 
the distillates of gilsonite or tabbyite. Gilsonite is soluble 
in stearin and hot paraffin but wurtzellite is insoluble in 
both. 
SUMMARY. 
1st. Considerable scattered work has been done, but 
it needs to be gathered together and reviewed carefully. 
2nd. Gilsonite is the Utah asphalt most fully in- 
vestigated. It is also the most important. 
3rd. The uses of these solid hydrocarbons are many 
and varied and are growing more numerous rapidly. 
4th. In the field one asphalt gradually changes into 
the other. The gilsonite occurring furthest east, then the 
' tabbyite, wurtzellite, rock asphalt, and ozokerite. There 
may be a genetic relationship among them. 
5th. All occur in rocks of the same age—Eocene of 
the Tertiary. 
6th. An interesting series of distillates is obtained at 
temperatures ranging from 220 degrees to 350 degrees C. 
7th. Gilsonite, tabbyite, ozokerite, and the bitumen 
from rock asphalt are soluble in many solvents to varying 
degrees but wurtzellite is practically insoluble in all the sol- 
vents tried so far. 
8th. Though gilsonite, tabbyite, and wurtzellite grade 
from one into the other in the field, are quite similar in 
appearance and very similar in chemical composition, still 
