PAPERS OX GEOLOGY AND CHEMISTRY 329 



Titration with electric light using this indicator was 

 however nmch easier than when Methyl Orange was 

 used. One or two experiments with the so-called daylight 

 electric light indicated that the titration was a little more 

 easily made with this light than when using ordmary 

 electric light. Excess alum interfers in the same way as 

 with Methyl Orange. Experiments have not been made 

 in substitutmg this indicator for Methyl Orange in other 

 titrations. TTe cannot say therefore whether it can be 

 recommended as a general substitute for Methyl Orange 

 but can recommend it as a substitute for Methyl Orange 

 in the titration of bicarbonates ^^'ith acid. 



THE ABSORPTION OF THE OXIDES OF NITRO- 

 GEN FORMED IN THE SILENT DISCHARGE 



By F. 0. AxDEREGG AXD K. B. McEachrox, Purdue 



University 



If the silent discharge process for the fixation of nitro- 

 gen is to be made sufficiently effective to compete com- 

 mercially with other methods very efficient absorption of 

 any oxides of nitrogen is quite necessary. In the arc 

 fixation of nitrogen the question of complete absorption 

 has received much attention because of the low concen- 

 tration of nitric oxide produced. In the silent discharge 

 process the most of the nitrogen which has been once 

 brought into combination with the oxygen is probably 

 oxidized completely so that it is readily absorbed in 

 water. On the other hand the concentrations are apt to 

 be rather low. Experiments with the silent discharge 

 process are being carried out at the Engineering Experi- 

 ment Station of Purdue University and considerable 

 study has been given and more will be needed before the 

 problem is solved. Since a report on this work is to be 

 read at the Boston meeting of the American Institute of 

 Electrical Engineers in April by C. F. Harding and K. 

 B. McEachron, only such points as are pertinent to our 

 subject will be discussed here. 



