1849.] 



exercised by Trees on Climaie. 



409 



ny of the momitains of that na,me enter the region of the clouds, 

 but the strata of primitive rocks dip at an angle of 70*^ or 80^ and 

 generally toward the north-west. In the interior of the province 

 we meet with spaces of land two or three leagues square, quite 

 destitute of springs. The sugar cane, indigo and coffee can grow 

 only in places where running waters can be made to supply the 

 artificial irrigations necessary during very dry weather. The first 

 colonists very imprudently destroyed the forests. Evaporation is 

 enormous on stony soil surrounded with rocks that radiate heat on 

 every side. In the eighth and tenth degree of latitude, in re- 

 gions where the clouds do not glide along the soil, many trees 

 are stripped of their leaves in the months of January and Eebrua- 

 ry, not on account of the sinking of the temperature as in Europe, 

 but because the air at this season, the farthest from that of rains, 

 has nearly attained its maximum of dryness. The plants with 

 very tough and glossy leaves alone resist this absence of humidity. 

 Beneath the fine sky of the tropics the traveller is struck with the 

 aspect, almost hibernal, of the country : but the freshest verdure 

 again appears, when he has reached the banks of the Oronoko 

 where another climate prevails, and the great forests preserve by 

 their shade, a certain quantity of moisture in the soil which they 

 shelter from the devouring ardour of the sun.* 



Ey felling the trees, that cover the tops and sides of the moun- 

 tains, men in every climate prepare at once two calamities for 

 future generations ; the want of fuel and a scarcity of water. 

 Trees by the nature of their perspiration and the radiation from 

 their leaves in a sky without clouds, sm^round themselves with an 

 atmosphere constantly cold and misty. They affect the copious- 

 ness of springs, not, as was long believed by a peculiar attraction 

 for the vapors diffused through the air, but, because, by sheltering 

 the soil from the direct action of the sun they diminish the evapo- 

 ration of the water produced by rain. When forests are destroy- 

 ed, as they are every where in America by the European planters 

 with an imprudent precipitation, the springs are entirely dried up 

 or become less abundant. The beds of the rivers remaining dry 

 during, a part of the year, are converted into torrents whenever 

 great rains fail on the heights. The sward and moss disappear- 



* reraonal JN'an'ative, vol. iv., n. 62, 



