Page:Popular Science Monthly Volume 15.djvu/232

220 What basis of facts have we for this alarm about carbonic oxide? Two chemists, within a very short time, have gone to work to determine the amount of the gas contained in the air in places where it was assumed to be present in considerable quantity. And with what results? Why, the specter vanished. In vain they sought for it—in this corner, in that, in the chimney, in the hot-air passages—but it was not there. There seems to be nothing left for the carbonic-oxide alarmists but to yield, and set about looking for another cause.

The special experiments to which I refer were carried out by Gottschalk in Leipsic, and Vogel in Berlin. Gottschalk, in a pamphlet entitled "Ueber die Nachweisbarkeit des Kohlenoxyds in sehr kleinen Mengen, und einige Bemerkungen zu der sogenannten Luftheizungsfrage," describes a process by means of which he could detect, as he shows by direct experiment, 0·22 part of carbonic oxide in 1,000 parts of air. He was commissioned by the authorities of the city of Leipsic to apply this process to the examination of the air in two of the public schools in the city. Two different kinds of hot-air furnaces were employed in these schools, and it was supposed that the air of the rooms was certainly contaminated with carbonic oxide. The experiments, however, proved that, if present at all, the gas could not be detected by a method capable of determining with certainty the presence of ·22 part in 1,000.

Vogel's experiments are not so delicate as those of Gottschalk, but still they are interesting for other reasons. His method consists in shaking the air under examination with water which contains a drop or two of blood, and then examining the liquid by means of a pocket-spectroscope. If ·4 per cent. of carbonic oxide be present the result is plainly perceptible in the spectrum of the light which has passed through the blood. The authorities of the city of Berlin commissioned Vogel, together with two other well-known experts, to examine the air of a number of schoolrooms in the city, with particular reference to the presence of carbonic oxide. The conclusion was simply that none of the gas could be detected by the blood method. Vogel argues further that a quantity of carbonic oxide in the air which can not be detected by his method can not act poisonously upon the concentrated blood of the human lungs.

Of course the experiments described do not prove conclusively that air is not sometimes rendered unwholesome by carbonic oxide, but they at least prove that this gas is not so widely distributed as it has been supposed to be for some time past.

Another constituent of the air which has from time to time attracted considerable attention is ozone. This has been supposed to be a health-giving principle in the atmosphere, and magical properties have been ascribed to it. The vitality of men is known to be subject to marked variations. On a cool, clear, bracing day the man is not