J 48 CALCAREOUS MANURES— PRACTICE. 



offensive matter were preserved and kept harmless by being combined 

 with marl, applied from time to time as required. But it should be re- 

 membered that, as yet, rapid and extensive as has been the progress of 

 marling in Virginia, there has. been no instance of the greater part of any 

 whole neighborhood 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 any where is the marling of all the cultivated 

 and arable land-; leaving unmarled, and as much as ever the abundant 

 sources of vegetable decomposition and of disease, all the wood-land, 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 

 maintained,) 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 fol- 

 lows, that the lands so left are 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 of every farm is left unmarled, and as 

 free as ever to evolve the agent of disease. So sure does this opinion seem 

 to me, tRat I have commenced acting on it, by marling the wood-land that 

 is not designed to be cleared for cultivation— and shall continue, as more 

 necessary labors permit, to do so, until not an acre of the farm is left with- 

 out being changed in character by calcareous earth. 



It is proper to add, as an opinion founded on but limited experience as 

 yet, that though the cases of sickness on Coggins Point farm have cer- 

 tainly diminished very greatly — there not being one case of late years of 

 bilious diseases, where there were twenty formerly— still that the diseases 

 seem to have changed in kind, and to have increased in severity and danger. 

 Formerly, there was almost no sickness except from ague and fever, (or, 

 very rarely, a case of mild bilious fever,) from which, though few persons 

 escaped through the autumn, and some suffered several relapses, the 

 attacks were rarely dangerous, and required little skill, and but a few 

 days to cure, for that time. Bad as was this state of things, it seemed that 

 the ague and fever acted as a safely-valve to the system, and while it sel- 

 dom permitted the enjoyment of long continued robust health, it prevented 

 the occurrence of more dangerous or fatal diseases, such as are the most 

 common among the fewer diseases of what are deemed healthy regions. 

 The fewer diseases of my adult negroes for the last twelve or thirteen 

 years have been of a more inflammatory kind, and are not confined to 

 autumn ; and there have been certainly more severe and fatal diseases, and 

 more that required medical aid, than formerly, when there was so much 

 more of sickness of one kind, and confined to one season. In short, it 

 seems that the diseases are no longer (or but in few cases) those of the 

 low country and of a bilious climate, but are more like those of the upper 

 country, which, though occurring but rarely, are generally of a more 

 serious nature. The facts on which this particular opinion has been formed, 

 are still too few, and of too short continuance, to attach to them much im- 

 portance ; and even if they were less doubtful, I have not the medical 

 knowledge to trace these new effects back to their causes, ttill, it is 

 deemed due to candor, and to the desire for a fiir and full investigation of 

 the subject, even if making against my own views, that these opinions 

 should be stated. There is no other subject, than this, taken in general, 

 which more deserves and requires investigation ; and in the present in- 

 choate state of the discussion, the expression of even erroneous opinions 



