“These properties are terrible; why not confess it? For the most infinitesimal quantity of this gas in the air we breathe is sufficient to arrest in three minutes the normal action of the lungs and to destroy life. “Everybody knows that carbonic-oxide (known in chemistry as CO) is a permanent gas without odor, color or taste, and nearly insoluble in water. Its density in comparison with the air is 0.96. It burns in the air with a blue flame of slight illuminating power, like a funereal fire, the product of this combustion being carbonic anhydride. “Its most notable property is its tendency to absorb oxygen. (The orator dwelt upon these two words with great emphasis.) In the great iron furnaces, for example, carbon, in the presence of an insufficient quantity of air, becomes transformed into carbonic-oxide, and it is subsequently this oxide which reduces the iron to a metallic state, by depriving it of the oxygen with which it was combined. “In the sunlight carbonic-oxide combines with chlorine and gives rise to an oxychlorine (COCL^2)—a gas with a disagreeable, suffocating odor. “The fact which deserves our more serious attention, is that this gas is of the most poisonous character—far more so than carbonic anhydride. Its effect upon the hemoglobin is to diminish the respiratory capacity of the blood, and even in very small doses, by its cumulative effect, hinders, to a degree altogether out of proportion to the apparent cause, the oxygenizing properties of the blood. For example: blood which absorbs from twenty-three to twenty-four cubic centimeters of oxygen per hundred volumes, absorbs only one-half as much in an atmosphere which contains less than one-thousandth part of carbonic-oxide. The one-ten-thousandth part even has a deleterious effect, sensibly diminishing the respiratory action of the blood. The result is not simple asphyxia, but an almost instantaneous blood-poisoning. Carbonic-oxide acts directly upon the blood corpuscles, combining with them and rendering them unfit to sustain life: hematosis, that is, the conversion of venous into arterial blood, is arrested. Three minutes are sufficient to produce death. The circulation of the blood ceases. The black venous blood fills the arteries as well as the veins. The latter, especially those of the brain, become surcharged, the substance of the brain becomes punctured, the base of the tongue, the larynx, the wind-pipe, the bronchial tubes become red with blood, and soon the entire body presents the characteristic purple appearance which results from the suspension of hematosis.