NITEOGEN AND CELLULOSE. 229 



20. The absorption of nitrogen by organic compounds takes 

 place likewise under the influence of loth kinds of electricity. 

 It takes place in just as well defined a manner with the lowest 

 as with the highest tensions, but in a time which is the longer, 

 the lower is the electric tension. It is very marked even 

 with the low tensions which no longer yield the oxides of 

 nitrogen. This absorption has been verified, both by insulating 

 the silver or platinum 1 armatures held in contact with the 

 paper and the gases, and also by insulating the paper itself 

 from all metallic contact between two glass surfaces. At the 

 same time as the fixed nitric compounds already referred to, and 

 under these conditions, no trace of ammonia was formed t and 

 no trace of nitric or nitrous acid, or of hydrocyanic acid. 



21. Working under similar conditions, and with very low 

 tensions, it was found that the fixation of the nitrogen was 

 especially abundant with paper, less with ether, and still less 

 with benzene, a diversity corresponding to the unequal stability 

 of these principles and to the different nature of the nitrogenous 

 principles derived from them. With paper especially, there 

 are produced at the same time insoluble nitrogenous com- 

 pounds, very slightly coloured, which remain fixed upon the 

 woody fibre, and nitrogenous bodies which are soluble in water 

 and almost colourless, which are condensed upon the sheet of 

 platinum ; the latter contain such large quantities of nitrogen 

 that they yield free ammonia which turns litmus paper blue, 

 even without any addition of soda-lime. 



22. The experiments just described define the general con- 

 ditions of the chemical reactions produced by the silent dis- 

 charge, but they do not indicate clearly the effects of the 

 electrical tension, free from all complications. In fact, in the 

 experiments made with the help of the Kuhmkorff apparatus, or 

 the Holtz machine, the tension changes continually during the 

 interval between the outer sparks, and this between limits that 

 vary by several thousand volts. 



What is the influence of these .incessant variations and the 

 sudden alternations accompanying them? Are the chemical 

 reactions determined by the very fact of these alternations and 

 the molecular shocks and vibrations resulting from them, or can 

 the chemical reactions be produced by a simple difference of 

 potential, or a simple determination of the gaseous molecules, 



1 The metallic armatures had been brought to a red heat in the open air 

 before each experiment in order to destroy every trace of organic matter on 

 their surfaces. Care must be taken not to touch them with the fingers. The 

 Swedish paper and the dextrine employed did not contain more than a ten- 

 thousandth part of nitrogen according to a special analysis, a proportion which 

 is of no account when a few centigrammes of paper are operated upon. This 

 verification must be made each time upon strips taken from the same sheet of 

 paper and in an alternate manner, the paper sometimes accidentally contain- 

 ing nitrogenous substances. 



