232 ORIGIN OF THE NITRATES. 



in series, the external armature with the negative pole of the 

 same battery. In this way there was a constant difference of 

 potential between the two armatures of tinfoil, separated by 

 the two thicknesses of glass, by the stratum of air between, and 

 lastly by the paper or dextrine applied to one of the cylinders. 

 Before the experiment the nitrogen was estimated in the paper 

 and in the dextrine (working upon two grammes of dry material), 

 and was found to be, in 1000 parts 



Paper -10, dextrine 12. 



At the end of a month (November), having worked at first with 

 a single Leclanche element, 



Paper 10, dextrine 17, 



mould had formed. There being no variation in the paper and 

 very little in the dextrine, the experiment was continued with 

 five Leclanche cells for seven months, the outside temperature 

 being raised little by little until at times it reached 30. Again 

 mould was observed. At the end of this period, in 1000 parts, 

 the nitrogen was found to be 



Paper *45, dextrine 1*92. 



The space between the two cylinders was from three to four 

 millimetres. Another trial, made at the same time, with nearly 

 treble the space between two other concentric cylinders, similar 

 to the first, gave, in nitrogen in 1000 parts 



Paper '30, dextrine 114. 



All these analyses go to establish the fact that there is a fixation 

 of nitrogen upon paper and upon dextrine, i.e. upon vegetable 

 substances that are not directly nitrogenous, under the influence 

 of excessively low electrical tensions. 



The effects are here provoked by the difference of potential 

 existing between the two poles of a battery formed of five 

 Leclanche cells, a difference that may be compared to atmospheric 

 electricity acting at short distances from the earth. 



5. The influence of the mould, observed in the course of the 

 experiments, cannot be taken into account, for Boussingault has 

 proved, by very careful analysis, 1 that this vegetable substance 

 does not possess the power of fixing atmospheric nitrogen. 



6. The influence of light did not enter into the above ex- 

 periments, in which the fixation of the nitrogen was effected in 

 total darkness. Other experiments, however, performed in the 

 light, showed that light does not impede the electrical fixing of 

 the nitrogen. 



7. The reactions just described are determined by very low 

 electrical tensions, the value of which is quite comparable to 

 those of atmospheric electricity, as is shown by the measure- 



1 " Annales de Chimie et de Physique," 3 e se*rie, torn. Ixi. p. 363. 



