Patent for chemical fire extinguishers "in which the acid-bottle consists of two concentric cylinders, the inner one of which is open at top and bottom, and which, when the bottle is placed in the cylinder containing the water and soda, potash, or other material, a compressed-air seal will be formed, preventing the acid and water from commingling; but when the bottle is inverted the seal will be broken, and the water and acid coming together will generate the gas." (Lines 18-28) Includes instructions and illustrations.