21G ]>io(j)'<ii>hjr of PxTzelhts. 



in its quantity of oxygen. After Berzelius had convineed 

 himself of the truth of this remark, he shewed how much the 

 two differed in their characters. This was the first example 

 of Isomerism. 



Berzelius connected the electro-chemical doctrine with that 

 of simple definite proportions. It was very natural that he 

 should apply the phenomena presented by the voltaic pile, 

 and especially the facts which in his first paper he had so 

 convincingly explained to the ordinary chemical processes. 

 He assumed, that in every chemical process there was a neu- 

 tralization of opposite electricities, in consequence of which 

 heat and light were produced in the same way as in the dis- 

 charge of a Ley den jar, the galvanic battery, or lightning, 

 with the difference, that these phenomena were not always 

 accompanied by chemical combination. 



Even at the very first Berzelius did not conceal from him- 

 self the difficulties which this theory involved. He assumed 

 that the atoms possessed electrical polarity, upon which de- 

 pended the electro-chemical phenomena attending their com- 

 bination. Thus the atoms of oxygen were regarded as hav- 

 ing a preponderance of negative electricity ; those of potas- 

 sium a preponderance of positive. The unequal intensity of 

 the electrical polarity in the atoms of different bodies, de- 

 pendent partly upon their temperature, was regarded as the 

 cause of the difference of force with which affinities are ex- 

 ercised. He altered his views of this subject at different 

 times, and finally admitted that it was very possible that he 

 was in error. 



In classifying bodies as electro-positive and electro-nega- 

 tive, Berzelius regarded oxygen and the elements resembling 

 it as electro-positive. Subsequently, however, he altered the 

 nomenclature, and more correctly called them electro-nega- 

 tive. Oxygen alone he regarded as absolutely electro-nega- 

 tive, all other bodies being only relatively negative or posi- 

 tive, just as they would be related to each other when their 

 compounds were exposed to the influence of the electric 

 pile. 



These views of Berzelius have been frequently disputed. 

 And in truth, the phenomena attending the greater number 



