48 REMARKS ON KENNEL LAMENESS. 



wish to prove. M. Arago goes on to say, " that 

 Seneca mentions in his questions on natural history, 

 that rain, however abundant it may be, never pene- 

 trates into the soil above ten feet ; he states that 

 he is certain of this from having made many careful 

 experiments with this object in view. It becomes a 

 question whether we must not have recourse to 

 internal vapours in explaining the existence of foun- 

 tains, which are situated far above the level of the 

 sea, whilst their source is also deep under a vast extent 

 of soil. According to the experiments of the great 

 number of naturalists, who have recently engaged in 

 these researches, the permeability of the earth would 

 be decidedly inferior to the limit assigned by Seneca. 

 Thus Marriotte maintains that m cultivated la?ids, the 

 heaviest rains of summer do not penetrate above six 

 inches. Lahire also has observed, that in soils covered 

 with vegetation, they, on no occasion, penetrate more 

 than two feet ; and he has likewise stated, concerning 

 a bed of naked earth, eight feet thick, that not a drop 

 of water had penetrated to the leaden plate which 

 supported it, during the fifteen years it had been 

 exposed to every atmospheric vicissitude. Buifon has 

 supplied the results of a similar experiment ; for he 

 mentions having examined in a garden a bed of earth 

 more than nine feet high, which had been undisturbed 

 for many years, and he noticed that the rain had never 

 penetrated more than four feet deep. These obser- 

 vations would be of the deepest import in the question 

 concerning the origin of fountains, if the surface of 

 the globe were covered with a layer of vegetable earth 

 of the thickness of two or three yards. But the very 



