CALCAREOUS MANURES— APPENDIX. 395 



gentle streams. To form or increase their evil qualities and tendencies, the 

 law has given full permission, and no small aid ; but it positively, though 

 mdirectly, forbids the drainage of all such extensive swamps, and preserves 

 them still as mere nurseries o[ disease. A general law for permitting and 

 facilitating, under proper regulations, the draining of these great swamps, 

 would be a measure which would be most beneficial, not only for improving 

 the healthiness, but for increasing the agricultural products of the country. 



But though the tendency of the general changes in the physical condition 

 of the countr}^ was to increase the causes of autumnal diseases, there 

 were numerous particular exceptions, in works serving to promote health. 

 Of this kind were the opening and straightening of the choked channels 

 of small rivers, and many large streams, in the hilly country, where there 

 was enough descent to enable each individual proprietor of flooded low- 

 ground to relieve it by operations confined to his own land. The effectual 

 drainage of much land of this kind has produced so much benefit to health 

 as in many cases to balance and even exceed the increasing pestiferous 

 effects of the neighboring mill-ponds. Such facts would be taken by most 

 persons as proofs that the increase of mill-ponds had not increased disease. 

 Such benefits have been produced by the gradual draining of the ex- 

 tensive low-ground of Gloucester, which in its former and natural swampy 

 state must necessarily have been an abundant source of malaria. This 

 change, together with other circumstances stated in the recent description 

 of that part of the country, has operated to render the Gloucester as free 

 from bilious disorders as any part of the tide-water region — save the ad- 

 joining county of Matthews.* The remarkable general state of healthiness 

 of all these very lov/ lands at present, as well as the exceptions and evident 

 causes of the exceptions, furnish the most clear and important evidence of 

 the truth of the position, that mill-ponds and floods of fresh-water discharged 

 over salt-marshes are the great sources of malaria in Virginia. As stated 

 formerly,! there are but few fresh-water streams discharged on salt-marshes 

 in these two counties, and not a pond-mill on the low-grounds, nor indeed 

 in the whole county of Matthews, save one on its border nearest the high- 

 land. The facts presented here alone will prove the great and certain 

 benefit to be obtained by even a partial and imperfect avoidance of the 

 action, separate and combined, of these two greatest sources of malaria. 



But although the general and average degree of sickness may have been, 

 and certainly is, much lessened of late years by the better drainage of very 

 many of the smaller swamps — the introduction and increase of more perfect 

 tillage, which includes better drainage of arable land — and, still more by 

 far, by the now extensive applications of marl and lime — yet it would be a 

 great and dangerous error thence to infer that the mill-ponds and the still 

 remaining irreclaimable swamps had become less injurious to health. Their 

 malignant effects are not only not lessened in the slightest degree, but must 

 continue to increase with time, as long as the present destructive legal 

 policy of Virginia remains. The growing beneficial operation of the other 

 and opposite influences, have indeed served to neutralize, counteract, and 

 even (in the most thoroughly marled districts) to greatly overbalance the 

 continually increasing disease-producing operation of the mill-ponds and 

 swamps ; but not to prevent its existence or power. The greatly beneficial 

 operation of calcareous manures especially in improving health, (which 

 operation has been so fully treated of in preceding parts of this work as 



♦ See the facts and reasons stated more fully at p. 179 ami 190, in vol. vi. of Farmers' 

 Register 



t The same p. 190, 



