144 CALCAREOUS MANURES— PliACTlCE. 



There prevails a vulgar but useful superstition, that there is " bad luck" 

 ill throwing into the fire any thing, however small may be its amount or 

 value, that can serve for the food of any living animal. It is a pity that 

 the same belief does not extend to every thing that as manure can serve to 

 feed growing plants— and that even the parings of nails and clippings of 

 beards are not saved (as in China) for this purpose. Kowev^er small each 

 particular source miglit be, the amount of all the manures that might be 

 saved, and which are now wasted, would add incalculably to the usual 

 means for fertilization. Human excrement, which is scarcely used at all in 

 this countiy, is stated to be even richer than that of birds; and if all the 

 enriching matters wei'e preserved that are derived not only from the food, 

 but from all the habits of man, there can be no question but that a town of 

 ten thousand inhabitants, from those sources alone, might enrich more land 

 than could be done from as many cattle. 



The opinions here presented are principally founded on the theory of 

 the operation of calcareous manures, as maintained in the foregoing part 

 of this essay, but they are also sustained to considerable extent by facts 

 and experience. The most undeniable practical proof of one of my po- 

 sitions is the power of a cover of marl to prevent the escape of all offen- 

 sive effluvia from the most putrescent anim.al matters. Of this power I 

 have made continued use for about eiglitcen months, and know it to be 

 more effectual than quick- lime, even if the destructive action of the latter 

 was not objectionable. Q,uick-lime forms new combinations with putrescent 

 substances, and, in thus combining, throws off effluvia, which, though 

 different from the products of putrescent matter alone, are still disagreea- 

 ble and offensive. Mild lime on the contrary absorbs and preserves every 

 thing — or at least prevents the escape of any offensive odor being perceived. 

 Whether putrescent vegetable matter is acted on in like manner by calca- 

 reous earth cannot be as well tested by our senses, and therefore the 

 proof is less satisfactory. But if it is true that calcareous earth acts by 

 combining putrescent matters with the soil, and thus preventing their loss, 

 (as I have endeavored to prove in chapter vhi.) it must follow that, to 

 the extent of such combination, the formation and escape of all volatile 

 products of putrefaction will also be prevented. 



But it will be considered that the most important inquiry remains to be 

 answered, to wit : Has the application of calcareous manures been found 

 in practice decidedly beneficial to the health of the residents on the land? 

 I answer, that long experience, and the collection and comparison of nume- 

 rous facts derived from various sources, will be required to remove all 

 doubts from this question ; and it would be presumptuous in any individual 

 to offer as sufficient proof, the experience of only ten or twelve years on 

 any one farm. But while admitting the insufficiency of such testimony, I 

 assert that, so far, [to 1833,] my experience decidedly supports my position. 

 My principal farm, until within some four or five yeai^s, was subject in a re- 

 markable degree to the common mild autumnal diseases of our low 

 country. Whether it is owing to marling, or other unknown causes, these 

 bilious diseases have since [to 1833] become comparatively very rare. 

 Neither does my opinion in this respect, nor the facts that have occurred 

 on my farm, stand alone. Some other persons are equally convinced of 

 this change on other land as well as on mine. But in most cases where I 

 have made inquiries as to such results, nothing decisive had then been ob- 

 served. The hope that other persons may be induced to observe and re- 

 port facts bearing on this important point has in part caused the appear- 

 ance of these crude and perhaps premature views. 



Even if my opinions and reasoning should appear sound, I am aware 



