CARBON MONOXIDE POISONING results from breathing atmospheres containing the gas. Carbon monoxide is produced by burning carbon-containing fuels in a deficiency of air or oxygen. Common producers are room heaters, gas ranges, automobile exhausts, mine explosions, blasting, iron and steel furnaces and burning electric installation. Since the gas is colour less, tasteless and odourless (in the concentration usually en countered), its detection is difficult. Mice and birds are more quickly affected by it than man. The activated iodine pentoxide indicator, however, detects the presence of dangerous amounts in less than one minute. The gas exerts its extremely dangerous ac tion on the body by displacing oxygen from its combination with haemoglobin, destroying the body tissue. Frequent symptoms are headache, weakness, nausea, fainting, paralysis of the nervous sys tem and slowing of pulse and respiration. Treatment is by re moval to fresh air; application of artificial respiration, administra tion of pure oxygen, or a mixture of 5% of carbon dioxide in oxygen for 20 min. or more ; stimulation of circulation ; complete relaxation; symptomatic treatment for after-effects.