692 



OSTERHOUT RESPIRATORY APPARATUS 



the carbon dioxide used, it was found that this gas was pure to the 

 extent of 97.2 per cent and on introducing this correction into the 

 calculation, the volume of pure carbon dioxide delivered per second 



TABLE II. 



Observed Times in Seconds for the Delivery of 10 Co. of the Four Gas Mixtures Con- 

 taining Respectively 0.4, 1, 2, and 4 Per Cent of Impure Carbon Dioxide 

 (B), Calculated Amounts in Hundred-Thousandths of a Milligram of 

 Pure Carbon Dioxide Delivered per Second to the Apparatus (F), 

 and Calculated Constants for the Apparatus (G). 



A. Impure carbon dioxide, per 



cent 



B. Observed times for delivery 



of 10 cc. of mixed gas, 

 sec 



C. Calculated volume of gas 



delivered per sec. (= -jVt 

 etc.), cc 



D. Calculated volume of im- 



pure carbon dioxide de- 

 livered per sec. ( = C X 

 A),cc 



E. Calculated volume of pure 



carbon dioxide delivered 

 persec.( = DX0.972),cc 



F. Calculated weight (in hun- 



dred-thousandths of a 

 milligram) of pure car- 

 bon dioxide delivered per 

 sec. {= E X 1.75984 X 

 100,000) 



G. Constants for apparatus 



(= Average time, Table 

 I,XF.) 



0.4 



297 



0.003367+ 



0.00001347- 



0.00001309- 



2.304- 



1,296+ 



296 



0.003378+ 



0.00003378+ 



0.00003283 + 



5.777+ 



1,282 + 



293 



0.003413- 



0.00006826- 



0.00006635- 



11.676+ 



1,238- 



298 



0.003356- 



0.00013424- 



0.00013048+ 



22.962+ 



1,318+ 



in each of the four tests was calculated (E). To change the quantita- 

 tive determinations of carbon dioxide from volumes to weights, the 

 volumes of this gas in cubic centimeters were multiplied by 1.75984, 



