The public forests of the Philippines are not sold, but are developed under a license system. Small operators usually work under ordinary yearly licenses for definite small areas. Exclusive licenses, or concessions as they are popularly called, are generally in the form of a twenty-year exclusive license to cut and extract timber and other forest products from a specified tract. The land itself is in no way affected by such a license. Only the timber and minor forest products are included. [Sawmills] At present there are about 50 sawmills of all sizes and descriptions operating in the Islands. About 12 of these can be compared to the average modern sawmills in the United States. The largest sawmills are located on timber concessions, while the others are operated under short-term licenses. The total cut of the sawmills of the Philippine Islands is about 100 to 130 million board feet per year. MINOR FOREST PRODUCTS.--This term includes all products of the forest except timber or lumber. Many of the minor forest products of the Philippines are at present almost unknown in the world's markets and are largely confined to local use. The most important are nipa, sugar, and alcohol; rattan, used in making furniture; Manila copal or almaciga, used in making high grade varnish; lumbang, a nut-producing high grade oil for varnish; dye-woods and barks; guttapercha and rubber; paper pulp; fibers suitable for making baskets, hats, mats, ropes, etc.; soap barks; pili nuts, declared by many as superior even to almonds; wax; and different kinds of medicinal plants. MINERALS The Islands are rich in mineral products, and it should not be long before the working of minerals should constitute one of its basic industries. The most important minerals are gold, silver, lead, zinc, copper, iron, coal, petroleum, sulphur, asphalt, asbestos, manganese, guano, mineral waters, gas, cement, and many others of minor importance. Gold.--There are a number of successful gold mines in the islands today. One of them is the Colorado mine in Masbate which produces P2,000 worth of gold a day at a cost of P1,000. Other successful mines are those of Paracale, Ambos Camarines; Baguio, Mountain Province; and Aroroy, Masbate. There are large areas of placer ground in Nueva Ecija, Mindanao, and Misamis. According to an estimate of the Bureau of Science, there are in all 800 to 1,000 square kilometers of placer grounds in the Philippines still undeveloped. The production of gold in 1916 was 2,265,789 fine grams, worth P3,011,755; in 1918 the production was 1,937,941 fine grams valued P2,575,970.