AND ITS EFFECTS UPON ANIMAL LIFE. ] 1 



Haldane and Smith, in 1893,(30), repeated the " Brow ii-Sequard " exi)eriment, 

 using five bottles, each of a capacity of 1 to U- litres, connected by means of tubes. 

 A mouse was placed in each bottle and ventihxtion established through the whole 

 system by means of a fi!ter-pum[i ; a small meter being placed between the last 

 bottle and the pump. Specimens of aii' leaving the last bottle were drawn oft' at 

 intervals for analysis. Full-grown mice were used. The mice in the last two 

 bottles were exposed to the full effect of the vitiated air for !")."> Iioiii's without 

 detriment. 



In a second experiment an absor[)tion tube containing pumice-stone saturated 

 with sulphuric acid was placed between the last two bottles. This exi)eiiment 

 was continued for thirty hours ; no serious effects were observed. The amount of 

 ventilation furnished was from 12 to 24 litres pei- houi'. The mice remained 

 normal after having been in the liottle three days and the percentage of carbonic 

 acid in the last bottle had varied fi'om 2.4 to 5.2, averasfinir about 3. 



They state that these expei'iments, like their formei' 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, (31), repoi'ted the results of experiments, made under the direc- 

 tion of Uffelmann, in which the condensed moisture of expired air was collected 

 by the methods usually employed, taking the precaution to cleanse his apparatus 

 with solution of KMuO^ 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 expii-ed, measured by a gas meter, was 

 found to be 3000 litres in eight hours, from which he collected 100 c. c. of fluid. 

 A distinct araniouia reaction was obtained upon 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 mg. 

 of oxygen necessary to oxidize one litre of fluid, or 15 mg. in 24 hours, which 

 denotes 0.0017 mg. per litre of expired air. The alkaloid reaction with AuCeg, 

 KI, phosphomolybdate of potash, gave negative results. 



He expired 500 litres through 150 c. c. of a 1 per cent, solution of HCl — 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 g., was warmed to the body tem- 

 perature and injected under the skin of the back of a white mouse without pro- 

 ducing observable symptoms. This fluid had a distinct odoi- not comparable to 

 anything. 



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



