220 THE POPULAR SCIENCE MONTHLY.. 



What basis of facts hare we for this alarm about carbonic oxide ? 

 Two chemists, within a very short time, have gone to work to deter- 

 mine the amount of the gas contained in the air in places where it was 

 assumed to be present in considerable quantity. And with what re- 

 sults? 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 Luftkeizungs- 

 frage," 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 em- 

 ployed 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. 



Yogel'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 at- 

 tracted 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 

 * " Bcrichte der deutschen chomiscben Gesellschaft," xi., 235. 



