UTAH ACADEMY OF SCIENCES 203 
indicating the suitability of each particular fraction as 
sources of solid paraffin and lubricating oils. 
The Bureau of Mines has examined hundreds of 
samples of petroleum from the different oil fields of the 
United States and has examined samples of shale-oil 
made in commercial operations in Scotland. All examin- 
ations were made in accordance with the procedure des- 
cribed above, and therefore in examining shale-oils a 
direct comparison can be made with many other oils 
whose properties and commercial products are known. 
Certain characteristics of shale-oils have not yet been 
directly tied up with corresponding properties of petrol- 
eum, but they will be in the course of time. Even now 
the method described affords an excellent method of 
determining the quality of a shale-oil. 
In its oil-shale work, the Bureau is endavoring to 
ascertain those conditions most suitable for producing 
an oil with a high percentage of paraffin hydrocarbons, 
or in other words, a low percentage of unsaturated hydro- 
carbons. It is interesting to note that when an oil low 
in unsaturated hydrocarbons is produced; or rather an 
oil with a small percentage soluble in concentrated sul- 
phurie acid, all the other desirable properties of the oil 
follow along with it; there is a high content of. solid 
paraffin wax; the motor fuel fractions are fairly volatile; 
and the viscosities of the lubricating oil fractions indicate 
that the oils will be suitable for making lubricants. How 
durable shale-oil lubricants will be is as yet not known. In 
general, it is possible to say that the percentage of the 
oil removed by sulphuric acid under the conditions of the 
test applied, as applied above, can be used as an index 
number upon which to base the relative values of shale- 
oils produced from different shales or the same shale 
under different conditions. 
