PHYSIOLOGICAL INFLUENCE OF OZONE HILL AND FLACK. 625 



Table III. 



1 Here the upper number represents the result of a further J^ hour of ozone, and the lower numbers that 

 of the succeeding y 2 hour in air. 



The subject was provided with a mouthpiece, fitted with inspiratory 

 and expiratory valves. (We used the excellent mica valves made by 

 Messrs. Siebe, Gorman & Co., and used in their mine rescue appa- 

 ratus.) While inspiring atmospheric air, the subject expired into a 

 large canvas-rubber bag of suitable construction, and previously 

 emptied of air. After a period of 10 minutes a fresh bag was sub- 

 stituted, and the volume of expired air in the first bag was measured 

 by pressing the contents of the bag through the meter, and a sample 

 of the expired air was collected and analyzed. Successive samples 

 were thus taken, some when the air was ozonized and some when it 

 was not. The composition of the atmospheric air being known, the 

 requisite data were calculated from the measurements of the meter 

 and the analysis of the samples, all results being reduced to 0° C. and 

 760 mm. 



In all we have made 19 experiments, and append the details of 

 the last 7. In the preliminary trials of the method we found con- 

 siderable variations in the metabolism in successive periods of time. 

 These were due to want of complete rest on the part of the subject. 

 (See Table IV.) 



Our last series of experiments were carried out with the subject 

 recumbent on a couch and prepared for the test by a preliminary 

 period of rest. Even then, the opening and shutting of the windows 

 38734°— sm 1911 40 



