622 



Scientific Proceedings, Royal Dublin Society. 



(6) Experiments with Oxygen. 



The oxygen was prepared by heating potassium permanganate in a hard 

 glass tube, and washing the gas with caustic potash to remove any traces of 

 carbon dioxide which might be formed. The apparatus was exhausted several 

 times with a water-pump to wash out the last traces of air. The gas was 

 collected over water which had been boiled for some time and cooled out of 

 contact with air. 



A series of experiments was made over a range of temperature of 35°, and 

 the results treated by the two methods as mentioned in the case of nitrogen. 

 The results are contained in Table VIII, and the variation of b with 

 temperature is shown in fig. 7. 



Table VIII. 

 Eesults of Experiments with Oxygen. 



In the above series of experiments the water in the tube at the end of 

 each experiment was analyzed for dissolved gases, using the extraction pump 

 and measuring apparatus described in Part I of this communication. The 

 solubilities of oxygen and nitrogen at the given temperatures as calculated 

 from these analyses are given in Table IX, as are also the values obtained 

 by Bohr and Winkler by absorptiometry methods. 



