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SCIENCE 



[N. S. Vol. XXV. No. 641 



lished in 1897. They had been preceded by a 

 work entitled ' Essai de Mechanique Chim- 

 ique,' also in two volumes, 1879, followed 

 by a volume, ' Traite pratique de Calorimetrie 

 chimique,' 1893. His two volumes ' Sur la 

 force des matieres explosives,' 1883, was inti- 

 mately connected with these other laborious 

 researches in thermochemistry, and led to the 

 discovery by others of smokeless powder. His 

 work on the detonation of endothermic sub- 

 stances, such as cyanogen and acetylene, was 

 followed by a research on explosive waves by 

 which he elucidated many seeming contradict- 

 ory facts. During the stirring times of 1870 

 Berthelot was made president of the scientific 

 committee on defense; he afterwards became 

 consulting member of the committee on powder 

 and saltpetre, and president of the commission 

 on explosives. In connection with these duties 

 he devised many original methods of research. 

 His thesis that chemical phenomena are 

 identical in animate and inanimate nature is 

 thus expounded in 1855 : 



we may, I say, claim to form anew all the sub- 

 stances whicli have been developed since the origin 

 of things, to form them under like conditions in 

 virtue of the same laws, by the same forces which 

 nature brings into play in their formation. 



And as a necessary sequel of his life's work 

 we find him attacking the serious problems 

 of the theory of agriculture and of biological 

 chemistry. His ' Chimie Agricole,' in four 

 volumes, and his ' Chimie Animale,' in two 

 volumes, were both published in 1899. 



The beautiful experiment farm at Meudon 

 was the scene of his labors. One climbs the 

 ' tour Berthelot ' of over eighty feet in height 

 and about one is the charming scenery of this 

 suburb overlooking Paris. Here the master 

 undertook his experiments on the influence of 

 electricity on the growth of plants — generating 

 this force or deriving it from the atmosphere. 

 Here it was that the fixation of nitrogen was 

 studied, a problem that has engaged the sturdi- 

 est minds, and here it was that he found that 

 microbic life was the means of transferring 

 atmospheric nitrogen to the living plant cell. 

 The import of this phenomenon he tersely 

 stated in saying : ' The soil is something 

 alive ! ' To us the products of whose broad 



acres furnish enough for ourselves and to 

 spare this discovery is of incalculable value. 

 And yet this man, who instructs us in eco- 

 nomic farming, does not hesitate to indicate 

 how we may manufacture our own food and 

 thus make ourselves independent of climatic 

 influences. 



The experimental investigation on plant life 

 led to that of the animal organism. The prin- 

 ciples of the production of heat in living be- 

 ings was a topic quite germane to the investi- 

 gations on thermochemistry. 



While Berthelot found his greatest pleasure 

 in experimentation in science he was fully 

 alert to the intimate relations his investiga- 

 tions bore to the advancement of the liberal 

 arts. He made his position in this regard 

 quite clear to the audience he addressed at the 

 second International Congress of Applied 

 Chemistry : 



In chemistry, as in all studies useful to man, 

 theory and practise are related to each other by 

 indissoluble bonds. 



Senseless the theorist who, shutting himself up 

 in the solitude of his egotistical personal views, 

 affects to disdain the incessant applications of 

 science to civilization, for the wealth and happi- 

 ness of mankind! 



Senseless, no less senseless, the practical man 

 who, satisfied with the knowledge acquired by his 

 ancestors, out of admiration for their conserva- 

 tism and tradition, opposes all progress, refuses 

 to enlarge or change the processes used in his 

 industry, that it may remain each day in com- 

 plete accord witu the newest and most advanced 

 theory 1 



No science probably, more than chemistry, shows 

 the necessity of this constantly renewed harmoni- 

 ous relation between practise and theory. 



To-day the trafiic of this great city, the in- 

 cessant tide of travel, the lighting of its streets 

 and homes, is effected by the aid of electricity 

 generated by the burning of coal, and the 

 specifications, under which the coal is bought, 

 require that its calorific value shall be deter- 

 mined by the bomb calorimeter, invention of 

 Berthelot, devised for theoretical purposes. 



While a great theorist, he invariably had 

 recourse to the experimental method for estab- 

 lishing his premises on a sure foundation. 

 His temperament was that of an idealist, of 



