THE STORY OF NINETEENTH-CENTURY SCIENCE 



one of Davy's greatest triumphs to prove, in the series 

 of experiments recorded in his famous Bakerian lecture 

 of 1806, that the alleged creation of elements did not 

 take place, the substances found at the poles of the bat- 

 tery having been dissolved from the walls of the vessels 

 in which the water experimented upon had been placed. 

 Thus the same implement which had served to give a 

 certain philosophical warrant to the fading dreams of 

 alchemy banished those dreams peremptorily from the 

 domain of present science. 



Though the presence of the alkalies and acids in the 

 water was explained, however, their respective migra- 

 tions to the negative and positive poles of the battery 

 remained to be accounted for. Davy's classical expla- 

 nation assumed that different elements differ among 

 themselves as to their electrical properties, some being 

 positively, others negatively, electrified. Electricity 

 and "chemical affinity," he said, apparently are mani- 

 festations of the same force, acting in the one case on 

 masses, in the other on particles. Electro-positive par- 

 ticles unite with electro-negative particles to form chem- 

 ical compounds, in virtue of the familiar principle that 

 opposite electricities attract one another. When com- 

 pounds are decomposed by the battery, this mutual at- 

 traction is overcome by the stronger attraction of the 

 poles of the battery itself. 



This theory of binary composition of all chemical 

 compounds, through the union of electro-positive and 

 electro-negative atoms or molecules, was extended by 

 Berzelius, and made the basis of his famous system of 

 theoretical chemistry. This theory held that all inor- 

 ganic compounds, however complex their composition, 

 are essentially composed of such binary combinations. 



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