328 Mineral Riches of the Philippines. [July, 



hurried a manner to enable me to furnish reliable par- 

 ticulars. As I have already remarked, geological examina- 

 tions are difficult, from the deep forests which cover the 

 interior. At the Cebu coal mines, which are situated in a 

 valley between two ranges of hills, into the second of which 

 the shafts are driven, I observed in the cuttings made 

 along the shoulders of the hills several old sea-beachers, 

 one above the other, at an elevation of some 500 feet above 

 the level of the sea, composed chiefly of rotted masses of 

 coral, some of them very large ; and close to the coal the 

 indurated clay filled with casts of fossil shells, most of 

 them bivalve and very difficult to determine. 



The matrix of the Mancayan copper is, I believe, a 

 porphyritic rock, but cannot speak with certainty. 



At one point in Cebu is noticed some masses of grey 

 marble with white veins, blasted from the side of the hill in 

 making the road to the mine, so handsome that, were the 

 distance from the coast less, it would be profitable to 

 quarry it for sale at Manila. 



No general geological survey has ever been made by the 

 Spaniards, and nearly, if not all the discoveries of minerals 

 in the islands, have been made by the natives in their 

 search for the precious metals. 



Considerable quantities of impure sulphur are brought 

 to Manila from the island of Samar, where it is dug and 

 fused in large blocks. It is said that much more might 

 be had were the demand for it larger. 



The bottom of the crater of the volcano of Zual, in the 

 province of Batangas, about 40 miles from the capital, 

 would also furnish a good deal of sulphur, which is con- 

 densed from two or three fnmaroles, almost constantly 

 ejecting sulphurous vapour, in which the north-east mon- 

 soon condenses upon the leeward side of the crater, giving 

 the ledges of the rocks the appearance of being covered 

 with snow. 



I am not aware that antimony, which is so abundant 

 in the neighbouring island of Borneo, has ever been dis- 

 covered in the Philippines, nor have any deposits of tin 

 been found. Zinc, as blende, accompanies the galena, and 

 in the north, near Mancayan, there are quantities of iron 

 pyrites, which are brought to the mines by the semi-wild 

 natives of the district to be used in the smelting operations. 

 In Mindanao, near Surigao, I have found very fine arsenical 

 pyrites most beautifully crystallised. 



There can be little doubt that much has yet to be dis- 

 covered in the way of valuable minerals in these islands, 



