312 ' A Dijfertation on the 



thors, however, who have treated it with an unbecom- 

 ing ridicule, would have fpared their wit, had they 

 known, that their own hypothefes, devifed more than 

 two thoufand years afterwards, were deftined to a lim- 

 ilar fate with that of the Grecian Philofopher. 



The Modern Theories may be reduced to three claffes. 



They all find the refources of Springs 

 In the Ocean ; 



In an Abyfs, in the bowels of the Earth ; or 

 In Vapour. 



Thofe, who draw the water of Springs from the 

 Ocean, have been puzzled to convey it to their orifi- 

 ces in the ftate in which we actually find it. Springs 

 are ufually frefti : the Ocean is fait. Moft Springs are 

 higher, and fome many thoufand feet higher, than the 

 level of the Ocean. To raife their fupplies requires, 

 therefore, a force fufficient to counteradi the force of 

 Gravity. 



Thefe difficulties, attending the firft clafs of theories, 

 have coft its advocates no fmall expence of labour and 

 ingenuity. Dts Cartes, to avoid them, kindled a 

 fire in the bowels of the Earth, by which he converted 

 the water of the Qcean into Vapour. This Vapour, 

 he coUeded in hollow fubterranean caverns, and thefe 

 condenfud it into water. Some of his followers, difpenf- 

 ing with thefe caverns, raifed their vapour thus form- 

 ed through the interftice^ of the ground, until it was 

 condenfed by cold near the furface. Had Des Car- 

 tes and his difciples adopted the rule, which after- 

 wards directed the refearches of Newton ; 



Never to afcribe a phenomenon to any caufe, until the ex- 

 iftcnce of that caufe is proved ; their fubterranean fire 

 would never have been- kindled. Perhaps, alfo, they 

 would have found the remote caufe of fprings in the 

 heat of a very different fire ; kindled, not merely in 

 the imagination, — and by the hand of One, all whofe 

 theories are only praftical. 



The exiftence of this fubterranean fire is a mere hy- 

 pothefis, — wholly unfupported by proof. So far as the 



