CATARACTS, AND INUNDATIONS. 9 



more remarkable in it than in those rivers; to wit, that at the ex- 

 tremity of its course, where there is no perceptible cavity, it is in- 

 gulphed, but without any fall ; the water passes between the pebbles, 

 and it is impossible to force a stick into that place any further than 

 into the betoirs of which we have spoken. What makes this river 

 take that subterraneous direction, is an impediment which its stream 

 meets with in that place ; it is there stopped by a rising ground six 

 or seven feet high, whose bottom it has very Jikely undermined, to 

 gain a free passage, not having been able to make its way over it. 

 At some distance it appears again ; but in winter, as there is a greater 

 quantity of water, it passes over that eminence, and keeps an unin- 

 terrupted course. 



Lastly, the Dr6me, after having lost some of its water in its 

 course, vanishes entirely near the pit of Soucy ; in that place it 

 meets with a sort of subterraneous cavity near 25 feet wide, and 

 more than 15 deep, where the river is in a manner stopped, and 

 into which it enters, though without any perceptible motion, and 

 never appears again. 



M. Guettard finishes this memoir with some observations upon 

 the lerre. This river is lost in the same manner as the Rille; and 

 though it is very near Paris, this singularity is unknown to almost 

 every body, was it not for the account of M. 1'Abbe le Bosuf, M. 

 Guettard would have been also ignorant of it. And as he thinks the 

 chief object of a naturalist's observation ought to be the public good, 

 he examines the means which might be employed to restrain the 

 water of the lerre. The same object has made him add a descrip- 

 tion of the manner how the Rhone is lost, or rather how its course 

 is disturbed; for it is now very certain that it does not lose itself, 

 but that its channel is extreir.ely confined, in the place where it was 

 pretended that it lost itself, by two mountains, between whose feet 

 it runs. M. Guettard makes it appear that it might not be impos- 

 sible to widen that place, and give a sufficient channel to the river, 

 which would render it navigable, and be of vast utility to all the 

 country. " 



Panfologtaj Art. Rivers. Phil Trans. Year 1690. 

 Mem, dc I'Acad. des Sciences. 



