44 
SIR J. B. LAWES AND PROFESSOR J. H. GILBERT ON THE 
temperature.. Such fixation was determined in the cases of benzene, oil of turpentine, 
marsh gas, and acetylene. In each case a solid nitrogenous body was obtained, from 
which ammonia was evolved on strongly heating. The electricity w^as developed by a 
large Ruhmkortf coil, so that the conditions were comparable with those between the 
clouds and the ground during a thunder-storm, and the application of the results to 
vegetation was legitimate for such conditions. He suggests that similar reactions 
probably take place in the air during storms, and when the air is charged with 
electricity, organic matters absorbing nitrogen and oxygen. 
Again in 1876 (‘Compt. Rend.,’ vol. 82, pp. ] 357-1360), he recurs to the subject. 
He says that under the influence of the silent electric discharge, nitrogen, whether 
pure or mixed with oxygen, is flxed by moist filter paper, and by dextrine, to a degree 
that is very noticeable within a few hours. Neither ammonia, nor any nitrogen acid 
is a product of the reaction; and thus the fixation may take place in nature without 
the preliminary formation of ozone, ammonia, or nitrogen acids. 
Subsequently (‘ Compt. Rend.,’ vol. 83, 1876, pp. 677-682), he used currents of much 
weaker tension, more comparable with those incessantly occurring m the air, and the 
substances experimented upon were moistened filter paper, and a strong solution of 
dextrine. The tension would correspond to that between the ground and a layer of 
air two metres above it. The experiments lasted about two months, during which, 
however, the tension varied considerably, but averaged 3^ elements Daniell. In all 
cases nitrogen was fixed by the organic substance, forming a nitrogenous compound 
from which ammonia was evolved by soda-lime. 
In 1877 (‘Compt. Rend.,’ vol. 85, p. 173) he gives further results of the same kind. 
In experiments in which the difference of electrical potential was not greater than that 
frequently existing between strata of the atmosphere not far from the ground, he 
found that filter paper moistened with water and containing O'OlO per cent, of 
nitrogen, after a month contained 0'045 per cent., whilst similar paper moistened with 
a solution of dextrine had its percentage of nitrogen raised from 0'012 to 0T92. He 
considered that his experiments indicated the true explanation of the fixation of 
nitrogen in nature. The gains are in amount such as would explain how crops 
acquire the amounts of nitrogen which he considers they must derive from the 
atmosphere. 
In the autumn of 1885 (‘Compt. Rend.,’ vol. 101, pp. 775-784) M. Berthelot gave 
the results of experiments on the fixation of atmospheric nitrogen by certain 
argillaceous earths. He refers to his experiments which established the fact that 
nitrogen was fixed in some of the immediate principles of plants by the agency of 
electricity of such feeble tension as is operative all over the globe. He has now to call 
attention to another mode in which free nitrogen is brought into combination—namely 
by argillaceous soils under the influence of micro-organisms. 
He experimented with two argillaceous sands, and two pure clays—crude kaolins. 
Some of the experiments were commenced in 1884, but others not until April, 1885 ; 
