54 THE BUREAU OF SCIENCE 



value of Philippine and other coals from the results of proximate analysis, 

 Phil. Journ. Sci., Sec. A (1909), vol. 4, No. 3, 171-203. Chemical and 

 physical characteristics of Philippine coal, Phil. Journ. Sci., Sec. A (1912), 

 vol. 7, No. 1, 1-17. The oxidation and deterioration of coal, Phil. Journ. 

 Sci., Sec. A (1912), vol. 7, No. 5, 297-315. 



Summary of the chief characteristics of Philippine coals, Mineral Re- 

 sources P. I. for 1907 (1908), 34-39. Philippine coal. Mineral Resources 

 P. I. for 1909 (1910), 36-40. Coal in the Cagayan Valley, Mineral Re- 

 sources P. I. for 1909 (1910), 41-42. The coal resources of the Philippine 

 Islands, Mineral Resources P. I. for 1910 (1911), 37-56. Coal resources 

 of the Philippines, Mineral Resources P. I. for 1911 (1912), 52-62. The 

 persistence of Philippine coal beds, Phil. Journ. Sci., Sec. A (1915), vol. 10, 

 No. 5, 289-301. The coal deposits of Batan Island, Bull. P. I. Min. Bur. 

 (1905), No. 5, 1-56. 



Asphalt in Leyte, Bureau of Science press bulletins 42 and 44. 



PHILIPPINE BUREAU OF SCIENCE CHART 9 



GOLD, SILVER, LEAD, COPPER, AND IRON 



[See prints in photograph stand.] 



Gold. — The production of gold is steadily increasing. The output in 1916 

 was worth over $1,650,000 (f*=3,300,000) . 



Silver and lead. — Silver is found alloyed with gold in practically all of 

 the gold deposits in the ratio of 1 part silver to 4 parts gold. Native silver 

 has been reported. Silver is found associated with galena in Bulacan, 

 Paracale, Marinduque, and Mindanao. A newly discovered 2-meter vein 

 of comparatively pure galena has been recently opened in Marinduque and 

 is said to be extensive. 



Copper. — Copper deposits are known to exist in several provinces. The 

 deposits at Mancayan, Mountain Province, Luzon, have been worked for 

 years, and large amounts of high-grade ore have been taken out. According 

 to reports of various examining engineers there are 500,000 tons of available 

 ore, averaging 2.5 per cent. Other copper deposits have been found in 

 Benguet, Pangasinan, Batangas, Mindoro, Masbate, Panay, and Mindanao. 

 The deposit in Pangasinan is being explored at the present time. 



h'on. — There are valuable deposits of iron ore in the Philippines, some 

 of them exceedingly well located for an economic handling of the ore. A 

 lack of proper smelting facilities has prevented their exploitation on a 

 large scale, but many small iron castings are produced each year in native 

 furnaces. 



A deposit high-grade hematite ore is available in Ambos Camarines and 

 in Bulacan. An unworked laterite iron-ore deposit in Surigao, Mindanao, 

 has been examined by Bureau of Science engineers, who estimate it to 

 contain over 500,000,000 metric tons of available ore averaging from 45 to 

 50 per cent iron. The deposit is located near a good harbor, and the ore 

 could be loaded with steam shovels at a low cost. Other valuable deposits 

 occur, but no detailed examination of them have been made. 



REFERENCES 



The Philippine Journal of Science, Section A; the Mineral Resources of 

 the Philippine Islands; and press bulletins of the Bureau of Science give 

 the information with regard to the metallic mineral resources of the Phil- 

 ippine Islands. 



