248 I'he Philippine Journal of Science me 



The pan is a piece of bark about i to | meter long by | meter 

 wide. About 6 centimeters of the sides are bent up and held in 

 position by two pieces across the top near the ends. These 

 pieces also serve as handles. The action in panning is very 

 similar to that of the belt vanner. The native places the pan 

 with ore on it in a small tank of water whose depth is just 

 sufficient to cover the top of the crosspieces. By grasping a 

 crosspiece in one hand and lifting, a current of water is caused 

 to pass over the ore and wash off the lighter material. With 

 the other hand the operator returns the mineral to the head 

 of the pan and again lifts. The motions are regulated to a 

 nicety, and the separation is very cleanly made. In order to 

 separate the gold from the rich sulphides, a slight side shake 

 and roll are given the bark pan. When handled by a skillful 

 manipulator, the gold seems to travel up and away from the 

 sulphide. The tailings are carefully saved and panned over in 

 the rainy season when mining is impossible. Some observers 

 have reported that the natives bury the tailings and expect the 

 gold to come back to them. This belief is easily explained by 

 the fact that the sulphides oxidize very rapidly after being 

 once ground and no doubt release some gold that is coated by 

 the iron sulphide. The fine-gold pannings are melted with a 

 small amount of lead in a wide clay crucible somewhat similar 

 to a scorifier. The melted product is poured and is then placed 

 in another clay dish with a covering of salt and given a chlorid- 

 izing roast. When this is done properly, the gold has a very 

 pure appearance, although in reality it is only about 700 fine. I 

 was unable to ascertain if this chloridizing was done with the 

 deliberate intention of deceiving the purchaser or merely to 

 improve the appearance of the product. Since the method of 

 buying after comparison on a touchstone has been adopted, 

 chloridizing has become obsolete. 



The Igorots have many curious superstitions in regard to 

 mining, and very great faith is placed in their religious offerings 

 to the "anitos," or spirits. These religious observances take 

 the form of canaos, or feasts, at which tapuy, a liquor 

 made from fermented rice, is drunk and animals are killed and 

 eaten. 



If a low-grade rock is encountered in mining, it is customary 

 to hold a caiiao to improve it. If a rich pocket is struck, a 

 stop must be made and a caiiao of thanksgiving is held. Mean- 

 while some Igorots, not quite so superstitious as the rest, may 

 slip down into the mine and steal the ore, leaving just enough 



