136 CLASSICS OF MODERN SCIENCE 

 nothing but an assemblage of a number of good conductors of a 

 different kind, arranged in a certain manner. Thus, 30, 40, 60, or 

 more pieces of copper, or better of silver, each applied to a piece of tin 

 or still better of zinc, and an equal number of layers of water, or of 

 some other liquid which may be a better conductor than simple water, 

 as salt water, lye, &c., or of bits of card or leather, &c., soaked in such 

 liquids. Of such layers interposed between each couple or com- 

 bination of two different metals, one such alternate series, and al- 

 ways in the same order, of these three kinds of conductors, is all 

 that constitutes M. Volta's new instrument ; which imitates so well the 

 effects of the Leyden phial or electric batteries; not indeed with the 

 force and explosions of these, when highly charged ; but only equal- 

 ling the effects of a battery charged to a very weak degree, of a 

 battery, however, having an immense capacity, but which besides 

 infinitely surpasses the virtue and the power of these same batteries ; 

 as it has no need, like them, of being charged beforehand, by means 

 of a foreign electricity ; and as it is capable of giving the usual com- 

 motion as often as ever it is properly touched. This apparatus, as 

 it resembles more the natural electric organ of the torpedo, or of the 

 electric eel than the Leyden phial and the ordinary electric batteries, 

 M. Volta calls the artificial electric organ. For the construction of 

 this instrument, M. Volta provides some dozens of small round 

 metal plates of copper, or tin, or best of silver, about an inch in 

 diameter, like shillings or half-crowns, and an equal number of 

 plates of tin, or much better of zinc, of the same shape and size. 

 These pieces he places exactly one upon another, forming a column, 

 pillar or pile. He provides also as many round pieces of card, or 

 leather, or such like spongy matter, capable of imbibing and retaining 

 much of the water, or other liquid, when soaked in it. These soaked 

 roullets or circles are to be a little less in diameter than the small 

 metal discs or plates, that they many not jut out beyond them. All 

 these discs are then placed horizontally on a table, one over another 

 continually alternating, in a pile as high as will well support itself 

 without tottering and falling down: beginning with a plate of either 

 of the metals, as for instance, the silver, then upon that one of zinc, 

 over which is to be put the soaked card ; then other three discs, over 

 these in the same order, viz. a silver, next a zinc, and then another 

 moistened card, &c. 



