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water. In charging the entire battery we used about four- 

 teen gallons of nitric and sixteen of sulphuric acid. I abstained 

 from using the solution of nitre through an apprehension that 

 it would cause the exciting mixture in the cast-iron cells to 

 boil over. I know not whether this apprehension is well 

 founded ; but I know that when ten or more cells are employed, 

 the exciting fluid in the cast-iron cells will soon boil over, and 

 produce nitrous fumes, if it does not contain one quarter of its 

 bulk of nitric acid. 



•' 1 have found by experiment that a cast-iron battery is 

 about fifteen times as powerful as a Wollaston battery of the 

 same size, and nearly as powerful and a half as Grove's. 

 Hence our new cast-iron battery, in which there are ninety- 

 six square feet of zinc, is equal in power to a Wollaston bat- 

 tery containing more than 1400 square feet of zinc, or more 

 than 13,000 four-inch plates, and to a Grove's containing 140 

 square feet of platina. Now the battery made by order of 

 Napoleon for the Polytechnic School, which was the largest 

 zinc and copper battery ever constructed, contained only about 

 600 square feet of zinc ; and the most powerful Grove's of 

 which I have seen an account did not contain twenty square 

 feet of platina. Hence the cast-iron battery belonging to the 

 College is more than twice as powerful as the largest Wollas- 

 ton, and seven times as powerful as the largest Grove's ever 

 constructed. 



" 1 shall now describe a few of the experiments which were 

 made with our large cast-iron battery on the 7 th of the last 

 month. The first experiment consisted in passing the voltaic 

 current through a very large turkey, which was instantly 

 killed by the shock. The craw of the turkey was burst, and 

 the hay and oats contained within it fell to the ground. In 

 order to give the shock, a piece of tin-foil, about four inches 

 square, was placed under each wing along the sides of the 

 turkey, which were previously stripped of their feathers, and 

 moistened with dilute acid. The tin-foil was kept in close 



