15S VOLTAIC BATTERY. 



zinc, below his tongue, by bringing the outer edge of these 

 pieces in contact, he will perceive a peculiar taste, and in 

 the dark will see a flash of light. If he put a slip of tin-foil 

 upon the bulb of one of his eyes, and a piece of silver in his 

 mouth, by causing these pieces to communicate, in a dark 

 place, a faint flash will appear before his eyes. Galvani sup- 

 posed that the virtues of this new agent resided in the nerves 

 of the animal, but Volta, who prosecuted this subject with 

 much greater success, showed that the phenomena did not 

 depend on the organs of the animal, but upon the electrical 

 agency of the metals, which is excited by the moisture of the 

 animal, whose organs were only a delicate test of the pre- 

 sence of electric influence. In exciting the electricity of 

 the pieces of silver and zinc, the saliva of the mouth answers 

 the same purpose as the moisture of the animal. 



The conductors of the galvanic fluid are divided into the 

 perfect and imperfect. The perfect conductors consist of 

 metallic substances and charcoal : the imperfect are water 

 and oxydated fluids, as the acids and all the substances that 

 contain these fluids. To render the Galvanic, or more 

 properly the Voltaic power sensible, the combination must 

 consist of three conductors of the different classes. When 

 two of the three conductors are of the first class, the combi- 

 nation is said to be of the first order ; when otherwise, it is 

 said to be of the second order. If a piece of zinc be laid 

 upon a piece of copper, and upon the copper a piece of flan- 

 nel, moistened with a solution of salt in water a«Vc/c of the 

 first class is formed ; and then if three other pieces be laid 

 on these in the same order, and repeated seveial times, the 

 whole will form a pile or battery of the first order. The ef- 

 fects may be increased to any degree, by a repetition of the 

 same simple combination. Tlie following is a cheap and 

 -easy method of constructing a Voltaic pile, for zinc is one of 

 the cheapest of metals, and may be easily melted, like lead. 

 Let a person cast twenty or thirty pieces of zinc, of the size 

 of a cent, which may easily be done in moulds made of clay. 

 Let him then take as many cents, and as many pieces of 

 paper or woollen cloth cut in the same shape, and which he 

 is to dip in a solution of salt and water. In building the 

 pile, let him place a piece of zinc, wet paper, the supera- 

 bundant water being pressed out, after which the copper ; 

 then zinc, paper, copper, and so on, until the whole be 



