220 



ORIGIN OF THE NITRATES. 



of the arc or that of a series of strong sparks, never shows any 

 sign of combination. It is the same with nitrogen brought 

 afterwards into contact with oxygen, and also with organic 

 substances. In all known cases it is necessary that nitrogen 

 and the organic substance, or hydrogen, or oxygen should 

 simultaneously undergo the electric action for the combination 

 to take place. 



3. The appliances in which the arc or spark is first caused to 



act on nitrogen can be easily 

 imagined. 



For the silent discharge the 

 apparatus shown in the annexed 

 figure is employed. 



The apparatus consists of a 

 glass tube, c, provided with two 

 tubular passages, a and ~b. An- 

 other tube, d, penetrates into the 

 first tube which surrounds it, and 

 is ground into it at c. It is filled 

 with a conducting liquid (water 

 acidulated with sulphuric acid), 

 the whole being placed in a 

 test glass filled with the same 

 liquid. 



The electrodes of a powerful 

 Euhmkorff machine communi- 

 cate with the liquid in the in- 

 ternal tube and with the external 

 liquid. 



The silent discharge takes 

 place in the annular space com- 

 prised between the tubes c and d. 

 It acts upon the gases which 

 enter at a and escape at b. The 

 3piSita=_ nitrogen which issues from this 

 H apparatus has acquired no fresh 

 property. 



4. The same negative results 

 Fig. 31. Berthelot's silent discharge were obtained by the author with 

 apparatus for the modification of hydrogen in presence of organic 



substances, either nitrogen or 



oxygen, immediately after the hydrogen had undergone the 

 action of the sparks, or of the silent discharge, results which are 

 very different from those observed with oxygen. There does 

 not therefore appear to exist for nitrogen or hydrogen any 

 permanent electrical modification, analogous to that of oxygen 

 forming ozone. 



