X, A. 4 Pratt: Petroleum and Residual Bitumens 263 



The Leyte natural bitumens are derived from a paraffin-base 

 petroleum. This fact at once distinguishes them from asphalt, 

 as most commonly defined, which is derived either naturally or 

 artificially from petroleum with an asphaltic base. The natural 

 bitumen from outcrops E, F, and G was classified at the time of 

 its discovery as gilsonite (or uintahite, another name for the 

 same mineral). But gilsonite is black and lustrous and breaks 

 with a perfect conchoidal fracture. The material from this 

 group of outcrops is dull brownish black and breaks with a 

 schistose fracture. Its specific gravity and its hardness are both 

 less than the corresponding figures for gilsonite. Moreover, gil- 

 sonite, according to Richardson," who has devoted a great deal 

 of study to this subject, is derived from a nonparaffin oil and is 

 not soluble in paraffin residues. All the Leyte bitumens are 

 paraffin-bearing and are, therefore, not gilsonite according to 

 Richardson. The bitumen from outcrop B is more nearly like 

 gilsonite in physical appearance, being brilliant black in color 

 and conchoidal in fracture. Its streak, however, is black, while 

 the streak of gilsonite is reddish brown, and it contains a large 

 proportion of paraffin. 



Grahamite, another natural bitumen, has something of the 

 physical appearance of the bitumen from outcrops E, F, and G; 

 Richardson states that it may be derived from paraffin petro- 

 leums. But grahamite is heavier than any of the Leyte bitumens 

 and has a higher proportion of fixed carbon. 



Ozocerite is defined as a native paraffin, the physical appear- 

 ance of which varies. Its color may be the same as that of some 

 of the Leyte bitumens, its specific gravity is somewhat less, and 

 it probably contains a higher average proportion of paraffin. 



The petroleum from Leyte is a light, fluid oil, olive-green 

 by reflected light and reddish brown by transmitted light. Its 

 character is shown by the fractionations recorded in the follow- 

 ing tables. Table IV contains the analysis of a sample which 

 was secured by Mr. William Anderson, of Tacloban, Leyte, from 

 the seepage at I and had probably deteriorated by exposure. 



Table IV. — Distillation products of petroleum from seepage I, Villaba, 



Leyte." 



Constituent. 



Percentage 

 by weight. 



Gasoline (110° to 170° C.) 



Kerosene (170° to 270° C.) 



Heavy oils (270° to 315° C.) ___. 

 Residue, pitch (above 315° C.) . 



0.88 

 17.51 

 19.91 

 61.70 



" Analysis by A. S. Arguelles, chemist. Bureau of Science. 



' Journ. Am. Chem. Sac. (1910), 2, 1032. 



134764- 



