The deaths from carbon monoxid poisoning in large cities now exceed those from any other poison. In Cook County our records show a steady increase in death by such asphyxiation. The total number of gas cases for 1916, 501, constitutes nearly 8 per cent. of the entire number of coroner's cases, taking fourth place in the numerical order of different forms of death for the year. The increase is to be attributed, not to carelessness or ignorance, but rather to the widespread knowledge of the ease with which carbon monoxid produces death, the more marked increase coming under the class of suicides, as shown in the accompanying tables.
Carbon monoxid occurs most commonly as a product of combustion in ordinary stoves, salamanders, furnaces, blast furnaces1 and gas engines;2 in fumes from explosions, and in "after damp" of explosions of methane and coal dust in mines; in mine fires,