Comparative Air-Analyses 



113 



appreciable increase in the percentage of oxygen. Furthermore, for fear 

 that simple contact might be inefficient, as a further precaution, in cer- 

 tain analyses on January 31 and February 1, the gas was passed into the 

 potassium pyrogallate 10 times at the end of the regular routine, but 

 with no appreciable increase in oxygen percentage. 



Table 71. 



-Results of comparative study of oxygen absorption by potassium pyrogallate 

 solutions of varying concentration. 



1 These were given an additional 12 minutes in the potassium-pyrogallate solution. 



2 After absorbing the oxygen in the regular way, the air was sent back and forth into the potassium- 

 pyrogallate solution 10 times before the reading was taken. 



Since the obvious inference is that there must have been a slight for- 

 mation of carbon monoxide with the weaker solutions, one questions 

 immediately if it is certain that even with the strong Haldane solution 

 there may not be traces of carbon monoxide. Haldane's experience in 

 detecting minute amounts of carbon monoxide goes a long way, however, 

 in establishing faith in his assertion that not the slightest trace is found 

 with the use of his concentrated solution. 



