SO GALVANIC ELECTRICITY. 



combination, which will give shocks when fifty are put together. 

 The other is copper, cloth of the same .size moistened with solution 

 moistened in the solution of the compound of sulphur copper, 

 and so on: the specific gravities of the solutions should be in 

 the order in which they are arranged, to prevent the mixture of 

 the acid and sulphuretted solution ; that is, the heaviest solution 

 should be placed lowest. 



FOJ these and various other progressive discoveries we are chiefly 

 indebted to Sir Humphry Davy ; as we are altogether for the great 

 discovery respecting the agency of voltaism, which was published in 

 the Philosophical Transactions, in a paper which gained the prize 

 proposed on voltaism by the French Emperor. This discovery may 

 be expressed in the following sentence: " The voltaic energy Ira* 

 the property of decomposing all compound substances (supposing 

 the battery sufficiently powerful) when the constituents range them, 

 selves round the wires, passing from the two extremities of the bat- 

 tery, according to the following law : oxygen and acids arrange 

 themselves round the positive wire ; hydrogen, alkalies, earths, and 

 metals, round the negative wire/' From this very important dis- 

 covery Sir Humphry drew several very plausible inferences. Oxy- 

 gen and acids, since they are attracted towards the positive wire, 

 are naturally negative ; while, on the other hand, hydrogen, alka- 

 lies, and metals, being attracted to the negative wire, are naturally 

 positive. When two substances are chemically combined, they are 

 in different states of electricity ; and the more completely opposite 

 these states, the more intimately they are united. To separate the 

 two constituents of bodies from each other, we have only to bring 

 them to the same electrical state ; and this is the effect which vol. 

 taism produces. Hence, chemical affinity is nothing else than the 

 attraction which exists between bodies in different states of elec. 

 tricity. The decomposition of the fixed alkalies, of the alkaline 

 earths and borucic acid, soon after discovered by the same cele- 

 brated chemist, was the natural consequence of his original disco- 

 very. These, though very striking and important, are not to be 

 compared, in point of value, to his original discovery of the decom. 

 posing power of voltaism, which has made us acquainted with a new 

 energy in nature, and put into our possession a much more efficient 

 chemical aent than any with which we were before acquained. 

 This is the discovery which does so much honour to Sir Humphry 

 Davy, and has put him on a level with the small number of indi- 



