EFFECTS OF CALXING ON HEALTH. 279 



.the nearness to the surface of the hard and impervious marly sub- 

 stratum, deprive the country of natural springs and running 

 streams ; and before the important discovery was made that pure 

 water might be obtained by boring from 800 to 700 feet through 

 the solid calcareous rock, the inhabitants used the stagnant rain- 

 water collected in pits, which was very far from being either pure 

 or palatable. Under all these circumstances, added to the rank 

 herbage of millions of acres annually dying and decomposing un- 

 der a southern sun, it might have been counted on,*as almost cer- 

 tain, that such a country would have proved very unhealthy. Yet 

 the reverse is the fact, and in a remarkable degree. The healthi- 

 ness of this region is so connected with and limited by the calca- 

 reous substratum and soil, that it could not escape observation ; 

 and they have been considered as cause and effect by those who 

 had no theory to support, and who did not spend a thought upon 

 the mode in which was produced the important result they so 

 readily admitted. Their testimony therefore is in this respect the 

 more valuable, because it cannot be suspected of having any such 

 bias. 



To the time when this last publication is made (1842) there has 

 been no reason to doubt the actual facts of autumnal diseases (the 

 effects of malaria} being greatly lessened by even the partial use 

 of marling; nor the inference that they would almost cease to 

 occur (if no mill-ponds and undrained lands remained), if all the 

 surface of a considerable extent of country were made calcareous, 

 and all rapidly putrescent and otherwise offensive matter were pre- 

 served and kept harmless by being combined with marl, applied 

 from time to time as required. But it should be remembered that, 

 as yet, rapid and extensive as has been the progress of marling in 

 Yirginia, there has been no instance of the greater part of any 

 whole neighbourhood of so much as a few miles in extent being 

 marled; nor even of all the surface of any one farm; and that, 

 therefore, we have no means of judging by experience of the full 

 measure of benefit to be derived from such a general change of the 

 character of the soil. The most that has yet been done anywhere is 

 the marling of all the cultivated and arable land ; leaving unmaiied, 

 and as much as ever the abundant sources of vegetable decompo- 

 sition and of disease, all the wood-land, steep hill-sides, and the wet 

 bottoms. Now, as the remaining wood-lands are generally among 

 the poorest of our soils, that is, (according to the theory maintain- 

 ed), soils incapable of combining with and retaining the products 

 of decomposition and as they are covered annually with leaves, 

 which in time all rot and their gaseous products finally pass off into 

 the air it follows, that the lands so left must be among the most 

 fruitful of malaria. It is obvious that the remedy is but partially 

 and inefficiently in operation, so long as from one-third to one-half 



