ON CHEMICAL ENERGY.* 



By Dr. W. Ostwald, 



Of the Universitjj of Leipzig. 



During- the scieiitilic developiiR'iit of chemistry tho liypotlieses wbich 

 have served as a primary toundation have always been borrowed from 

 a prominent sister seience. At the time of the most rapid development 

 of mechanics as founded by Galileo and advanced by his pupils and 

 successors, chemistry was mechanical; the solvent action of acids upon 

 metals was explained by assuming' that the former possessed points and 

 edges by means of which they disintegrated the latter; bodies which 

 combine were supposed to have hooks by means of which they attached 

 themselves to each other. When Newton based his theory of astro- 

 nomical movements upon the assumption of a force acting inversely as 

 the S(piare of the distance, chemistry shortly appropriated this idea, 

 and traced all processes to the attraction and repulsion of particles. It 

 is therefore not surprising that the phenomena of the Voltaic pile 

 (which later proved to be so intimately connected with chemical changes) 

 were at once utilized to serve as a foundation for a theory of chemical 

 processes. These theories, especially that of Berzelius, have prevailed 

 a long time, but finally have proved themselves just as insufficient to 

 represent chemical phenomena as the mechanical and the attraction 

 theory. 



Thus the theory of chemical combinations is to-day a strange and 

 contradictory conglomerate of the fossil constituents of the earlier 

 theories. The rudiments of the theory of attractions still play the most 

 important role, while there is also considerable discussion about posi- 

 tive and negative elements, 1. e., the residues of the electro-chemical 

 theory, and in most recent times we see the long-forgotten mechanical 

 conception again stejiping to the front in stereo-chemistry and being 

 accepted by many as a new step in the progress of science. 



In such times it is of great value, on the one hand, to recall the his- 

 torical development and the evanescence of theories; on the other hand 

 to find in the older theories that which is useful and correct, so as to 

 obtain sound building material for a new theory. 



* Read before the W^orld's Congress of Chemists, Aiij^nst 26, 1893. (From Journal 

 of the American Chemical Society, August, 1893, vol. xv, pp. 421-430.) 



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