X, A, 4 Pratt: Petroleum and Residual Bitumens 273 



Both the physical characters and the chemical compositions of 

 the other residual bitumens make them unfit for use in pave- 

 ments. Materials of similar character are widely used in Amer- 

 ica and Europe for other purposes, however, and are more 

 valuable than paving asphalt. The utilization of these bitumens 

 in the Philippines is complicated by the restricted local market 

 for the products made from them elsewhere. Their exploit- 

 ation, therefore, if they are developed in quantity, must be pre- 

 ceded by the establishment of a market either locally or through 

 exportation. The purposes for which they can best be utilized 

 is a subject for chemical investigation, but the following list 

 of possible uses for gilsonite and related asphaltic substances 

 may be quoted:'^ 



The manufacture of black, low-grade brush and dipping varnishes, such, 

 for instance, as are used on the various kinds of ironwork, and as baking 

 japans; * * * for preventing electrolytic action on iron plates of ship 

 bottoms; for coating barbed-wire fencing, etc.; for coating sea walls of 

 brick or masonry; for covering paving brick; for acid-proof lining for 

 chemical tanks; for roofing pitch; for insulating electric wires; for smoke- 

 stack paint; for lubricants for heavy machinery; for preserving iron pipes 

 from corrosion and acids ; for coating poles, posts, and ties ; for toredo-proof 

 pile coating; for covering wood-block paving; as a substitute for rubber in 

 the manufacture of cotton garden hose; as a binder pitch for culm in 

 making brickette and eggette coal. 



Some of these possible products would find no market locally, 

 and chemical investigation may prove the Leyte bitumens un- 

 suited for the manufacture of many of them, but it would also 

 undoubtedly reveal other uses to which they might be put. The 

 analyses already performed show that some of the bitumens 

 are high in paraffin, a substance which is used locally in the 

 manufacture of matches and candles and which could probably 

 be exported at a profit, since it is worth in the crude state about 

 34 centavos per kilogram. 



Another possible use for the Leyte bitumens and bituminous 

 mixtures is suggested by the exploitation of the so-called kero- 

 sene shales in Scotland and in New South Wales. The Scotch 

 shales yield upon distillation about 96 liters of crude oil per 

 metric ton. The crude oil, upon fractionation, yields in turn 

 6 per cent of gasoline, 32 per cent of kerosene, 24 per cent of 

 heavy oils, and 12 per cent of paraffin scale.^* According to 

 the distillation tests quoted on another page, 1 ton of the 



"Eldridge, G. H., op. cit., 356. 



" Lewes, Vivian B., Liquid and Gaseous Fuels. Archibald Constable 

 & Co., Ltd., London (1907), 97. 



