MARCELIN BERTHELOT——-MATIGNON. 677 
results which follow from this I may call special attention to the 
curious fact that nitrogen, oxygen, and oxide of carbon, up to 4,000 
degrees, have identical molecular specific heats, which tends to prove 
that the molecule is not dissociated at this high temperature during 
the very short period of heating. Theoretical studies on explosives, 
on the speed of explosions, were to lead to the discovery of smokeless 
powder by M. Vieille, the pupil and collaborator of Berthelot. This 
was for some time to give superiority to our armament. 
In collaboration with Péan de Saint Gilles, Berthelot, in 1862, in a 
celebrated memoir, defined equilibrium, and at the same time showed, 
by a full series of reactions methodically worked out, the réle of 
time in chemical phenomena. He endeavored to translate into 
mathematical formule the results of his experiments. He introduced 
the idea of active masses, and established a relation which, slightly 
modified, was to lead Guldberg and Waage, the following year, as 
they themselves acknowledged, to the establishment of the law of 
mass action. For his study on etherification the name of Berthelot 
deserves to be inscribed by the side of those of Saint-Claire Deville 
and of Raoult, among the creators of physico-chemistry. 
By reason of his studies of synthesis, the role of nitrogen in the 
organic world always interested Berthelot. Some years ago this 
element was considered as an inert body incapable of entering in 
reaction and yet it is indispensable to the life of animals and plants. 
By what process does inorganic nitrogen pass into the state of organic 
nitrogen? The problem is to-day in great measure solved, thanks 
particularly to Berthelot’s experiments. 
Under the influence of electrical actions, spark or current, the nitro- 
gen and oxygen of the air enter into combination to form, first of all, 
oxide of nitrogen, and then, by secondary reaction, nitrous vapors. 
Likewise, all active combustion, like that of charcoal, for example, 
quickens the combination of quantities of nitrogen and oxygen. The 
difference of electrical potential between two strata of air of unequal 
levels may be employed to effect the absorption of nitrogen by the 
most varied bodies. By exact quantitative experiments Berthelot 
showed that exterior electrical actions, storms, differences of poten- 
tial, and the combustions of charcoal, going on year after year in the 
world, are insufficient to calculate the total quantity of nitrogen nec- 
essary for the development of plants. Other causes must be found. 
For this reason Berthelot devoted himself to the study of the sun. 
He showed that the earth was enriched in nitrogen under the influ- 
ence of the tiny particles that swarm here. The organic world was 
no longer considered inert; it became a living entity in which a race 
of the tiniest midgets work to introduce the elementary nitrogen of 
the air into the cycle of organic reactions. 
