PHILIPPINE COALS AND THEIR GAS-PRODUCING POWER. 
By Atvin J. Cox. 
(From the Chemical Division, Bureau of Science.) 
Although coal occurs so abundantly in the Philippines, native coal is 
used only sparingly as a fuel. It has been employed on the small vessels 
plying along the coast with fairly satisfactory results, but, largely owing 
to the undeveloped condition of the mines and the difficulty of transporta- 
tion, it has come very little into competition with the coal imported from 
Japan and Australia. 
The Philippine coals are deposits of the so-called black lignites but are 
superior to ordinary lignite in every respect. It is rather the exception 
for these coals to have a brownish color and they never show a woody 
structure. In appearance they are usually black and shiny, much resem- 
bling bituminous coal, but have a slightly lower calorific value than the 
latter. On the other hand, they have a much higher calorific value than 
ordinary brown lignite. 
A great many formule which have been found to approximate the 
truth have been proposed? for the calculation of the total amount of 
heat obtainable on the combustion of coals, from their ultimate analyses. 
Dulong’s formula is said to give results with a probable error not exceed- 
ing 2 per cent—that is, they differ by not more than 2 per cent from the 
value obtained by experiment in the bomb calorimeter. 
Fewer attempts have been made to derive a formula for the calculation 
of the calorific value of coals from their proximate analyses. In 1896 
Goutal ? deduced a formula from the calorific determinations of some 
600 coals of different kinds, by which the results of calculation in nearly 
every case agree within 1 per cent with those of experiment. Gill * 
says that the results upon a series of American coals varied less than 
2 per cent from those obtained by the calorimeter. Such a formula is 
*Formule of Dulong, Gmelin, Cornut, Ser, Scheurer-Kestner and Meunier- 
Dollfus, Ann. Chim. Phys. (1886) (6), 8, 267; and Bunte, J. f. Gasbeleuchtung, 
34, 21-26 and 41-47. 
* Rev. d. Chim. ind. (1896) 7, 65.; Compt. rend, Acad. d. sc., Par. (1902) (12), 
135, 477-479. 
* Gill, A. H.: Gas and Fuel Analysis for Engineers, New York (1902), p. 90. 
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