14 Experimental Philosophy. [Lecture 2. 



the stone or arrow falling to the ground, they 

 have called the attraction of gravity, or gravity 

 tion. The second, that of the two leaden balls 

 adhering together, and of the water ascending 

 into the pores of the sugar, they call the attrac- 

 tion of cohesion, and also capillary attraction. 

 The third is electrical attraction, because the 

 sealing-wax, when chafed or warmed by rubbing, 

 is in an electrified or excited state, like the glass 

 cylinder of an electrical machine when rubbed 

 against the cushion, and therefore attracts the 

 hair, feathers, 8tc. The fourth is the magnetic 

 attraction ; and the fifth is called chemical attrac- 

 tion, or. the attraction of combination, because 

 upon it many of the processes and experiments in 

 chemistry depend; and because by this means 

 most of the combinations which we observe in 

 salts, the ores of metals, and other mineral bodies, 

 are effected. 



On the two first of these species of attraction 

 only I shall at present enlarge ; because it will be 

 necessary to treat of the others when we come to 

 investigate those branches of science to which 

 they properly belong. 



First, therefore, of gravitation. It requires no 

 experiment to show the attraction of gravity; 

 for since the earth is in the form of a globe, it is 

 manifest that it must be endued with a power of 

 attraction to retain upon, its surface the various 

 bodies which exist there, without their being 

 hurjed away into the immensity of space in the 



