398 THE COMPOSITION OF EXPIRED AIR. 



They state that, these experiments, like their former ones on rabbits 

 and man, are distinctly against the theory that a volatile poison other 

 than carbonic acid exists in the expired air. 



Beu, in 1893 (25), reported the results of experiments, made under 

 the direction of Uffelmann, in which the condensed moisture of expired 

 air was collected by the methods usually employed, taking the precau- 

 tion to cleanse his apparatus with solution of KMn0 4 and distilled 

 water, and likewise sterilizing the apparatus before it was brought 

 into use. The saliva is collected in a Woulff bottle attached before 

 the condenser. The amount of air expired, measured by a gas meter, 

 was found to be 3,000 liters in eight hours, from which he collected 

 100 c. c. of fluid. A distinct ammonia reaction was obtained uj>on 

 the addition of Nessler's reagent. Nitrate of silver failed to show the 

 presence of chlorine. 



Its reducing power upon solution of permanganate of potash showed 

 50 milligrams of oxygen necessary to oxidize 1 liter of fluid, or 15 mil- 

 ligrams in twenty-four hours, which denotes 0.0017 milligrams per liter 

 of expired air. The alkaloid reaction with AuCl 3 , KI, phosphomolyb- 

 date of potash, gave negative results. 



He expired 500 liters through 150 c. c. of a 1 per cent solution of 

 HG1, then evaporating to dryness on the water bath. A yellowish- 

 brown deposit remained. This deposit, dissolved in distilled water, 

 formed a fatty layer on the surface of the slightly yellow fluid. The 

 whole quantity, 1.5 grams, was warmed to the body temperature and 

 injected under the skin of the back of a white mouse without produc- 

 ing observable symptoms. This fluid had a distinct odor not compar- 

 able to anything. 



He next confined a mouse in a sealed glass vessel, having a globe 

 attached, with potash solution to absorb the carbonic acid; 3,200 expi- 

 rations of air were conducted into the glass vessel during the three 

 hours; no effect noticeable. In a second experiment the carbonic acid 

 was not absorbed, the experiment lasting four hours ; no effect. 



He repeated the Brown-Sequard experiment, using white mice in 

 four glass cages. The death of the animals, he believes, was due to 

 changes in the temperature and the accumulation of moisture in the 

 jars. He believes the protection afforded by H 2 SO± in Brown-Sequard 

 and d Arson val's experiments was due to its abstraction of the mois- 

 ture from the air. An acute poisoning through the organic matters 

 contained in the expired air he believes to be impossible, at least as not 

 shown by anything in his experiments. 



Bauer, in 1893 (26), used white mice confined in glass vessels of 

 about 1£ liters' capacity, the bottom of which was covered with oats. 

 The cork was perforated by three tubes. One of these passed down 

 near the bottom of the vessel and served for the entrance of air; the 

 second terminated just below the cork and served for the exit of air, 

 and the third extended down to about the height of the animal, but 



