EFFECTS OF CALXING ON HEALTH. 281 



their lands long enough to judge of the effects on health j and 

 whether upon true or false grounds, the opinion among such per- 

 sons seems now (1842) almost universal (so far as I have heard 

 opinions expressed), that the prevalence of autumnal diseases, the 

 product of malaria, has been invariably and manifestly lessened 

 since the lands were in part marled or limed. My individual ex- 

 perience and observations on this point, now of nine years' more 

 extent than when the first fruits thereof were stated in a foregoing 

 part of this chapter, concur with the more general and loose 

 information derived from' others, in confirming my position. It 

 sometimes happens that the very fact of an opinion being univer- 

 sally admitted prevents the obtaining such proofs of its truth as 

 would certainly have been ready, if the opinion had been questioned 

 and denied by many sceptics. And such is the state of the pro- 

 position now under consideration. Even in the few years which 

 have passed since I first advanced the opinion that the use of cal- 

 careous manures served to improve health, that opinion has become 

 so general, and is deemed so certain and unquestionable, by those 

 persons who have used those manures, that but few facts can be 

 learned of them sufficiently exact to serve as proofs because no 

 person has deemed it necessary to collect and preserve proofs of 

 what none doubted. "When asking for such proofs, as I have often 

 done, of cultivators and residents in various parts of the marl 

 region, I have rarely obtained any, except new declarations, from 

 every person interrogated, of concurrence and entire faith in the 

 general opinion that marling or liming had served greatly to abate 

 the prevalence of autumnal diseases. Such" general belief and con- 

 fidence in an opinion so recently promulgated, cannot be altogether 

 founded on error. (1842.) 



When my opinions of the beneficial operation of calcareous earth 

 in soil, or mixed with putrescent matter, in destroying or disarming 

 the sources of disease, were first published, and until after the 

 second publication of the same in 1835, I had no knowledge that 

 similar grounds had been taken by any other person. But since, 

 in the recent publications of a French writer, M. Puvis, I have 

 found the same general opinion expressed, and many important 

 facts given in confirmation. However, while I gladly accept the 

 important aid of M. Puvis's facts, as proof, I do not admit the cor- 

 rectness of his reasoning thereupon. Some of the former will be 

 quoted in the following passages. For his full views, see the 

 translations of his essays " On Lime as Manure," and " On Marl/' 

 both contained in vol. iii. of the Farmers' Register. 



" The results of marling may be considered in a point of view 



more elevated, and still more important than that of the fertility 



which it gives to the soil ; they may perhaps have much influence 



on the healthiness of a country where it" becomes a general practice. 



24* 



