:Si Mechanical Philosophy. [Chap, I. 



this pile exhibits; the coiinexiion which these phe- 

 nomena indicate with the principles both of elec- 

 tricity and of chemistry ; and the nmnerous expe- 

 riments and siiccef^sive improvements in the ma- 

 nagement of tliis Galvanic battery by .Me3sr$. Car- 

 lisle, Nicholson, Crnickshank, Davy, and others,. 

 of Great Britain ; by van Marum, of Holland ; 

 and by Fourcroy^ \'auquelin, and Thenard, af 

 France, have not only excited much attention in 

 the scientific world, but may also be ranked among 

 tlic rich additions to philosophy which modern 

 times have produced. 



-It must be admitted, however, that little more 

 has been done,, in this new branch of philosophy, 

 tlian to ascertain a number of facts, sometimes 



placed. on each other ^ tlien another piece of ziiic, aiad so on in 

 the order of the first layer. In this manner, the pieces are to be 

 arranged, or in any other manner, provided a regular alternation 

 l)e oliserved, until the requisite number shall be laid. The in- 

 urnment is then lit for use. The pieces of card should be- some- 

 ^ iiat less than the pieces of metal, and, after being well moisten- 

 "t.!, should be gently squeezed before they are applied, that the 

 superfluous moisture may not run down the pile, or insinuate 

 ithclf between the pieces of metal. 



U he instrument constructed in this manner affiords a perpetunl 

 cuncnt of the Galvanic influence ; and if one hand be applied t€? 

 tlie lov.est plate, and another to tlie uppermost, a shock is felt, a? 

 often as the contact is repeated. The shock received fronj thi^'i. 

 pile is somewhat like that ' given by a Leyden phial ; but more 

 nearly resembles that given by a Toi^cdo, w hich animal this appa- 

 ratus also resembles in giving incessant shocks. The inteilsit)^ of 

 tlui charge , is, Jio\ve\ er, too small to make its way tluougii .the 

 dry skin. J it. is Lliereforc necessary that each hand should be well 

 v.clted, and a piece of metal be grasped in each to make tlie 

 LoucJi ; — and the larger the piece of meud' which is thus l^eld in 

 the hand, the stronger ihv. shock. Garaett's Mfuils of Phihsi 

 \u\. i, p. 10, Uc. 



