68 HISTORY OF GALVANISM. 



PLATE i. ceived, that when glass vessels were used, the 

 alkali might proceed from a partial decomposition 

 of the glass ; and after trying various other sub- 

 stances, at length conical vessels of gold were 

 employed. With these precautions, and when the 

 water was very carefully prepared, neither acid nor 



Neither alkali were obtained ; and consequently the author 



acid nor . . __ , " . 



alkali concludes that in all those experiments, which 

 generated. were a | ten( j e( j w ^ contrary results, the acid 



and alkali must have proceeded from some ex- 

 traneous source, not having been generated, 

 but evolved, either from something held in solu- 

 tion by the water, or from some of the materials 

 employed in the apparatus. Perfectly pure water, 

 when subjected to the action of electricity, af- 

 fords nothing except oxygen and hydrogen. 

 Decompo- The very powerful action of the galvanic elec- 

 cafthVand tricity, in the decomposition of various earthy and 

 "aits'* 1 saline compounds, as experienced by Sir H. Davy 

 in the researches above-mentioned, offered an ex- 

 tensive field for farther investigation. Hisinger 

 and Berzelius, in the valuable memoir to which 

 I have already referred, noticed the tendency 

 which different bodies possess, to attach them- 

 selves to one of the wires exclusively ; acids and 

 analogous bodies being attracted to the positive, 

 while alkalies, metals, and all inflammables, were 

 attracted to the negative wire. Our author had 

 observed similar phenomena in his own experi- 

 ments, and was induced to make them the more 

 immediate subject of his examination. Acids and 



