SECTION 1. Section one of Act Numbered Fourteen hundred and ninety-nine, entitled "An Act to prevent the use of explosives and poisons for Inking fish in the waters of the Philippine Islands," is hereby amended so as to read as follows:
"SECTION 1. The use of dynamite or other explosive for the killing or taking of fish, or under water tor any purpose except in actions the execution of bona fide engineering work and the destruction of wrecks or obstructions to navigation, shall be unlawful: Provided, That nothing in this Act shall be understood to interfere with or prohibit the use of mechanical bombs for the killing of whales, crocodiles, sharks, or other large dangerous fishes: And provided further, That the Secretary of the Interior may issue permits for the use the explosives in taking fish in limited numbers for scientific purposes only."