366 CLEARNESS OF LIME-STONE WATERS. 



action. And it is believed, whether marl beds be so exposed or 

 not, that the low grounds on the streams of colourless water are 

 always much better soils, and of more durable fertility, than those 

 washed by coloured waters. The latter soils being often swampy, 

 are full of vegetable matter, and of course would be very productive 

 when first drained and cultivated. But these soils are far from 

 being among the most durable, and they are even at first, and when 

 in best condition, very inferior lands to most low grounds of prime 

 quality; and the latter are always penetrated by streams, or had 

 been sometimes covered by floods, which, however turbid at certain 

 times with suspended clay and mud, are never coloured by vegeta- 

 ble extractive or soluble matter alone. 



If we go farther for examples, the effects will be found to be 

 still more striking. None of the lime-stone streams are ever 

 coloured ; and their remarkable transparency, very far surpassing 

 that of the most pure and limpid waters of the low country, show 

 that the dissolved lime, which the mountain streams contain, serves 

 to remove everything of colouring matter. These lime-stone wa- 

 ters, and land floods from rains which also necessarily carry dis- 

 solved carbonate of lime, form the principal supply of the upper 

 James river. But long before the waters reach the head of tide, 

 not a particle of lime remains. The dissolved lime had been con- 

 tinually uniting with the suspended or dissolved vegetable matter, 

 until no lime was left, and the precipitated compound had served 

 to add more manure to the extensive low-grounds along the whole 

 course of the upper James river, and which are so well known and 

 deservedly celebrated for their great and enduring fertility and 

 high value. 



When a resident of the lower country first visits our mountain 

 and lime-stone region, he cannot avoid observing and being forcibly 

 impressed by the remarkable clearness of the waters. Pools and 

 basins in the streams containing six feet depth of water, will ap- 

 pear-to his unpractised eye as not deeper than two or three feet. 

 And it is only by comparison, and by becoming acquainted with 

 this really and perfectly clear lime-stone water, he learns that he 

 had, in truth, never before seen a stream or pond of perfectly clear 

 water. Though the dissolved matters may be in too small quan- 

 tity to produce any appearance of colour, they serve to impair the 

 transparency of the water. And when any such colouring or 

 vegetable matters are received into and intermixed with lime-stone 

 Btre^ns, the vegetable matter is immediately combined with lime, 

 and the compound precipitated ; still leaving in the water a great 

 excess of dissolved lime, scarcely diminished by the loss of the 

 small part acting to clear the water of all colouring and vegetable 

 impregnation. 



From the large proportion of lime held in solution by liine-stone 



