8 MCDOUGALL AND HowLES, Nitric Acid from Air. 



of 220 watts, operating for 20 hours, produced 3S-44 grms. 

 of nitric acid. This is equivalent to 98 grms. of nitric 

 acid per horse-power per 12 hours. 



A second experiment gave almost identical results. 

 The voltage on the open secondary circuit during these 

 experiments was 7,000, which fell to 1,100 when the 

 discharge was passing. The current taken was only 0"2 

 ampere. 



It was now decided to substitute a combustion- 

 chamber of form and capacity different from the one already 

 in use. A stoneware bottle {Fig. 4) 30 cm. in height, 

 and 10 cm. in diameter, was procured. The electrodes 



Fig. 4. 

 entered the vessel diametrically at A, A'. E represents a 

 small glass plate through which the behaviour of the 

 flame and the adjustment of the terminals may be 

 observed. Air was supplied to the flame through the 

 tube CD, which was let into, the bottom of the vessel 

 directly under the flame. The interior end of the tube 

 CD was covered with very fine wire-gauze. In this way 



