460 



SCIENCK PROGRESS 



jacket of the lamp. On working the induction coil a glow dis- 

 charge was caused to pass through the lamp and led to the 

 formation of an arc between the reservoirs of mercury. 



The reaction vessel was connected on the one side with a 

 reservoir of air and a series of drying tubes, and on the other 

 with a wash bottle which contained a reagent to absorb the 

 products of the exposure. A mercury Topler pump was placed 

 at the end to enable exhaustion and complete drying of the 



Fig. 1. 



apparatus and delivery tubes and in order to conduct experi- 

 ments at reduced pressures. 



During the operation of the mercury arc, on account of the 

 heating effect in the central portion of the apparatus and the 

 water cooling of the outside vessel, a very non-uniform tempera- 

 ture would be obtained in the annular reaction space, and it was 

 not attempted to keep any part of the apparatus below 15 . 



Accordingly, in the respect of temperature, the conditions 



