Additional Xotes. 591 



co\ierecl tliat a pile may be construct«.>d with oiu* ni<*tal only, pro- 

 vided proper fluids of tlitleront kintls be appliod to its ditVerent 

 surfaces. And he found tliat a sinillar result takes place with 

 respect to charcoal alone, if a like diversity in tlie fluids applicl 

 to its different surt'aces be duly oteerved. Mr. Davy also disco- 

 vered that the energy of the pile is nearly in p-roportion to the 

 rapidity with which the zinc becomes oxydated ; and, consequently, 

 that the effects will be found to be most powerful when nitric 

 add is interposed between the metals. I'his seems to be one of 

 the first steps towards the true thecjry of the action of Voltas 

 pile. 



Most of the improvements by the British philosophers above- 

 mentioned were communicated to the public In the course of the 

 year 1601 j a year very memorable for the number, variety, and 

 itnportance of tlie additions made to the stock of knowledge in 

 ihis science. 



Roused by the success aini eclat of the British discoveries w hich 

 have been just detailed, the votaries of this science on the conti- 

 nent of Europe soon began to furnish their additional contribu- 

 tions. 



Tromsdorff* found that gold leaf, and other metallic leaves, may 

 readily be subjected to combustion by being lixed to the zinc end 

 of the w ire of Volta's pile. 



Fourcroy made the remarkable discovery, that the shock is 

 greater in proportion to the accumulation of the nnnthcr of plates 

 in the pile, and the combustion in proportion to the extent of their 

 surface. 



Dr. van Marum, of Holland, and professor Piaft', of Kiel, suc- 

 ceeded in charging electrical batteries of 140 feet square, by a sin- 

 gle contact witli the pile of Volta, and proved that this pile is a true 

 excitatory apparatus of electricity. I'hey melted, by the electri- 

 city of this apparatus, a large portion of iron w ire, and evou wire of 

 platina. The communication of Dr. van Maium on this subject 

 to signor Volta (see Annates de Chijnie, torn. 40} is highly intc- 

 restin"-. He charged both single jars and large batteries by means 

 of the pile, and always found that they were charged to the same 

 degree of intensity with that which the pile itself indicated to the 

 electrometer. He found, also, that the shocks given by the battery, 

 when charged from powerful electrical machines, were not per- 

 ceptibly different from those given by batteries charged from tlie 

 pile. He found, further, that piles which consist of the same 

 number of plates, but of different diumetirrr, ^avc equal intensities. 



