THE FARMER AT HOME. 183 



> r ater. To increase the effect, all that is needed is to increase the 

 umber of these plates, either in the same trough, or in a number of 

 roughs, and all connected together, the whole constituting the bat- 

 ery. Sir H. Davy constructed a voltaic battery which contained two 

 housand of these double plates of zinc and copper, each plate six 

 nches square, and twenty of them in a trough ; that is, one hundred 

 .roughs in all. 



Galvanism produces an intense heat, sufficient to ignite and fuse 

 the hardest metals, and even the most refractory earths. Galvanism 

 is a most powerful agent in causing decomposition. By increasing the 

 strength of the battery, substances held together by the most powerful 

 affinity are easily separated. We have thus been enabled to ascertain 

 the composition of some, till then reckoned simple ; and new bodies 

 have also, by its aid, been discovered, which have themselves proved 

 powerful means of analysis. About the beginning of this century, Sir 

 Humphrey Davy subjected a number of substances to the action of a 

 powerful battery, by which he discovered the compound nature of 

 many ; and illustrated, by numerous instances, the chemical changes 

 produced by this wonderful agent. 



GARDENING. Gardening is the art of forming, planting, cul- 

 tivating, and managing garden grounds, whether of the ornamental 



GARDEN IMPLEMENTS. 



or culinary kinds. In a more enlarged sense, it is the business of 

 rendering the rural objects of nature more agreeable, interesting, and 

 useful to mankind ; in the execution of which, the operator has the 

 whole range of country scenery at his command, in order to select 

 with taste such parts as are the most appropriate and suitable to his 

 particular views and purposes. 



Gardening is one of those arts that most obviously, from the ne- 



