Formaldehyde. This pungent gas can be produced by passing the vapor of wood alcohol over coarsely powdered platinum heated to redness. Various forms of generators and formaldehyde candles are in trade, and many of them are highly efficient. "Pormalin" (pure medicinal) is a 35% aqueous solution formaldehyde. It is a non-corrosive antiseptic used in surgery in 1/4 to 1/2% solution usually, and up to 2%. As a vapor or spray, I to 2%; for collyria, 1-20% solution. "Cystogen" is an ammonia formaldehyde salt, valuable internally to prevent the decomposition of urine in the bladder. It prevents or arrests the growth of pyogenic bacteria in the urine. Dose, 5 to 7 gr., two to four times a day, dissolved in hot water.

"Pormin," "Aminoform," and "Urotropin" are practically the same thing. The U. S. P. has an official title for it -Hexamethylenamina, and the average dose is given as 4 gr. All these preparations are the same thing practically, and liberate formaldehyde by their decomposition in the body.