NITROGEN AND WATER. 223 



line in the atmosphere, there are very widespread surfaces 

 which gradually become electrified by influence, then suddenly 

 discharge themselves at the moment of the explosions (return 

 shock). Over these electrified surfaces there are exerted certain 

 chemical reactions analogous to those developed by the silent 

 discharge at a high tension and with a suddenly varying 

 potential. These are, moreover, accidental, local, and momentary 

 effects, as well as those of lightning properly so called. It is 

 probable that they are especially produced on mountains and 

 isolated peaks. 



3. The electric influence thus causes the formation of hypo- 

 nitric and nitric acids, and even that of pernitric acid, 1 an un- 

 stable compound produced by the reaction of the silent discharge 

 at a high tension on a mixture of hyponitric acid and oxygen. 



4. Nitrogen and water. Under the influence of high electric 

 tensions, free nitrogen and water combine to form ammonium 

 nitrite, according to the author's experiments 2 



N 2 + 2H 2 = NH 4 N0 2 , 



the energy necessary for this reaction ( 73 '2 Cal.) being 

 supplied by electricity. 



5. The effects just described are produced under the influence 

 of external discharges of the Euhmkorff coil, the potential of 

 the electrified bodies thus passing in a very short interval of 

 time through all values, from zero to a limit amounting to 

 several thousand volts. 



6. The same effects also take place, each pole being alternately 

 charged with positive and negative electricity, as with the 

 Euhmkorff coil, or each pole being constantly charged with the 

 same electricity, as may be obtained by the Holtz machine. 



7. But these reactions gradually become weakened if the 

 potential be lowered, and finally cease entirely, when it fails 

 below a certain limit, relatively very high, that is, reaching to 

 several hundred volts. Below this limit nitrogen and oxygen 

 cease to combine, although ozone is still formed. 



8. It should be noted that this limit of potential is far higher 

 than the ordinary tensions which atmospheric electricity can 

 assume, except in stormy weather. The direct formation of the 

 oxygenated compounds of nitrogen in nature is, therefore, limited 

 to the conditions of very great electric tension and the influence 

 of storms. 



9. We will examine, from the same point of view, the com- 

 bination of nitrogen with hydrogen ; that is to say, the formation 

 of ammonia by the action of electricity. 



1 "Annals de Chimie et de Physique," 5" se"rie, torn. xxii. p. 432. The 

 author had noticed the formation of the last combination ; but it has been 

 demonstrated in a more complete manner and studied more particularly by 

 Chappuis and Hautefeuille. 



2 Same collection, 5' se*rie, torn. xii. p. 455. 



