UTAH ACADEMY OF SCIENCES 91 
called Malthenes and those insoluble in carbon tetrachloride 
but soluble in carbon disulphide are called carbenes. Gener- 
ally carbon disulphide will dissolve all the malthenes and 
the carbenes. These solubility tests were made by allowing 
a one gram sample finely ground, to be in. contact with an 
excess of the solvent for 12 to 18 hours. The solution and 
the remaining solid material were then filtered through a 
tared gooch crucible made up of a filter of ignited asbestos 
fiber. The crucible was reweighed after being washed with 
pure solvent and dried at 100 degrees C. The increase is 
the amount insoluble in the solvent. From this the amount 
soluble is found. Great difficulty was found in filtering 
some of these samples, especially the Trinidad asphaltum. 
This material contains a large amount of fine sand which 
clogs the filter. No agitation accompanied these extrac- 
tions except through a shaking at first and one after about 
three hours. 
The bottles were corked to prevent evaporation of the 
solvent. In order to facilitate filtering the solid matter 
was allowed to settle as completely as possible before filter- 
ing. The clear solution was poured through the filter, then 
the solid matter washed into it. The insolubility of wurtz- 
ellite is to be noted, as we have occasion to observe this 
property in connection with later extractions. 
The results in Table 1 show physical and chemical 
properties which may or may not depend upon the ultimate 
analysis. Table 2 gives the ultimate composition as de- 
termined in our work. The carbon and hydrogen were de- 
termined by the ordinary combustion method, collecting the 
water in calcium chloride and the carbon dioxide in potas- 
sium hydroxide. Great care must be taken in starting a 
combustion. The part of the tube containing the copper 
oxide and lead chromate should be red hot but the part 
where the boat is placed should be cool when the boat is 
inserted. If not the gases which are first distilled off will 
come too fast to be decomposed by the copper oxide and to 
be absorbed by the potassium hydroxide bulb, and a back 
pressure will be set up which may puncture the hot tube or 
