( 591 ) 
Force and Rapidity. The Lake of Geneva, and the 
Boden-Sea, the two largeft in Swiferland, evidently 
eV1 j CC ii a .t I here aflert, and the others above-named 
gradually decreafe in Largenefs, in proportion as the 
Rivers, which fall into them, are lefs and lefs rapid. 
The extreara Smallnefs of the Alpine Plants is ano- 
ther Obfervation, I intend to make. They become lefs 
and lets, in proportion as the Mountains, upon which 
■ they grow, rife higher. Whether this be owing to the 
bharpnefs and Purity of the Alpine Air, or the decreaf- 
ing 1 reifure of the Atmofphere, which is far lefs upon 
^ than in Valleys and lower Countries, or to 
a Want of a fufficient Quantity of fubterraneous Heat, 
to pulh the Nourilhment into the Roots and Veflels of 
the Plants, or rather to a joint Concurrence of thefe 
and other Caufes, would require a more leifurely Con- 
” f e r ra 5J on ' The ^ is an indifputable Matter 
of fad, and it extends alfo to Trees and Shrubs, which 
become fmaller, as they grow higher. Nay, what is 
itill more remarkable, no Trees will grow beyond a 
certain Height, which is the Reafon why the Tops of 
Mountains appear fo bare and naked, if viewed at a 
Dilhnce, though a curious Traveller fhall not fail 
meeting upon their rich Paftures with an agreeable Vari- 
ety of Deautiful Plants. The Height, where the Trees 
ceafe to grow, hath been found, by Barometrical Obfer- 
vations, nearly to be the fame in divers Parts of Swiffer- 
land. Otherwife, the Smallnefs of the Alpine Plants is a- 
bundantly compenfated by the Richnefs of their Virtues' 
which are, as it were, purpofely centred there into fo 
narrow a Compafs. 
But to another Obfervation. The Mountains are 
much more abrupt, and fteep, and the Precipices greater 
Kkkk 
