INVESTIGATIONS. 2 2 I 



were speedily discovered, the existence of which had never before been 

 imagined. Oxygen, chlorine, and acids were all dragged, as it were, to the 

 positive pole, while metals, inflammable bodies, alkalies, and earths became 

 determined to the negative pole of the (galvanic) battery. When wires 

 connected with each extremity of the new battery were tipped with prepared 

 and well-pointed charcoal, and the points brought near each other, then 

 a most intense and pure evolution of light followed, which on separating 

 the points extended to a gorgeous arc." So the elements of all bodies were 

 separated and the composition of their compounds closely investigated. 



Michael Faraday threw himself con amore into the question. He set 

 about to classify the pile phenomena, and arranged them with appropriate 

 terms, and in a series of papers, between the years 1830 and 1840 (see his 

 4t Experimental Researches "), he explained the chemical effects of voltaic 

 electricity and electro-magnetic induction. He showed that the electricities 

 obtainable from the voltaic pile and the electrical machine are essentially 

 the same in their action. He proved that the theory held respecting the 

 necessity for the presence of water in electro-chemical composition was 

 erroneous, and that many other fluids and compounds were equally effective. 

 We have not space at our disposal to include a digest of his various lectures 

 and papers. He calculated that as much electricity is employed in holding 

 the gases oxygen and hydrogen together in a grain of water, " as is present 

 in a discharge of lightning." When water is decomposed by the electric 

 current, the force which determines the oxygen and acid matter held in solution 

 to the positive, while the hydrogen passes to the negative pole, is not in the 

 poles, but in the body decomposed, he says. " The poles," writes Faraday, 

 " are merely the surfaces or doors by which the electricity enters into or 

 passes out of the decomposing substance. They limit the extent of that 

 substance in the course of the electric current, being its termination in that 

 direction. Hence the elements evolved passed so far and no farther." 

 Faraday named the poles " electrodes " the way (in or out) of electricity. 



A very simple voltaic pile may be constructed with "gold-leaf" paper. 

 Take two sheets of the gold paper and paste them back to back, and two of 

 silver paper ; cut them into discs about the size of a five- 

 shilling-piece (or even of half-a-crown), and place them one on 

 the top of the other, so as the gold and silver may be alternate ; 

 press the discs together slightly when a good many layers have 

 been piled up, and introduce them into a glass tube ; close the 

 ends of the tubes with corks through which wires are passed 

 from the discs top and bottom. It will be found that the ends 

 are charged with opposite electricities. This is the Zamboni 

 pile, or the dry pile, which was constructed of hundreds of 

 paper discs " tinned on one side, and covered with binoxide 

 of manganese on the other," put into a tube, and closed with n g . 22 i.-The 

 brass stoppers. The electricity will last a long time in a dry pile. 



In the accompanying illustration of the Galvanic Pile a disc of copper 



