390 



FARMERS' REGISTER 



[No. 7. 



and azote — that the limed soil, in furnishing to 

 plants the lime which they need, relieves the soil 

 and plants from employing their powers to pro- 

 duce it — and finally, that lime promotes the forma- 

 tion of fixed substances, earthy or saline, necessa- 

 ry to vegetables. All this whole of reciprocal ac- 

 tion and reaction of lime; on the soil, plants and at- 

 mosphere, explains in a plausible manner, its fer- 

 tilizing properties. We would, consequently, have 

 nearly arrived at the resolving of an important ag- 

 ricultural problem, upon which were accumulated 

 all these doubts. 



The amount of lime taken up by vegetation. 



40. The ashes of plants from calcareous soils, 

 or those which have been made so by manures, 

 contain 30 per cent, of the carbonate and phos- 

 phate of lime, which, by taking off the crop, is 

 lost to the soil. But. the product of limed land of 

 middle quality, is during the two years of the 

 course of crops, about 20,000 lbs. of dry products 

 to the hectare, which contain a little less than a 

 hectolitre of lime in the calcareous compounds of 

 the ashes. The vegetation has then used half an 

 hectolitre a year. But we have shown that there 

 was necessary, on an average, three hectolitres 

 per hectare, each year. Vegetation then does not 

 take up, in nature, but a sixth of the lime which 

 is given profitably to the soil: the other five-sixths 

 are lost, are carried away by the water, descend 

 to the lower beds of earth, are combined, or serve 

 to form other compounds, perhaps even the saline 

 compounds, of which we have seen that lime so 

 powerfully favors the formation. Another portion 

 also, without doubt, remains in the soil, and serves 

 to form this reserve, which in the end, dispenses, 

 for many years, with the repetition of liming. 



Of the exhaustion of the soil by liming. 



41. "Lime," it is said, "only enriches the old 

 men: or it enriches fathers, and ruins sons." This 

 is indeed what experience proves, when, on light 

 soils, limed heavily, or without composts coming 

 between, successive grain crops have been made 

 Avithout rest, without alternations of <jrass crops, 

 or without giving to the soil alimentary manures 

 in suitable proportion. It is also what has hap- 

 pened when magnesia, mixed with lime, has car- 

 ried to the soil its exhausting stimulus. But when 

 lime has been used in moderation — when, without 

 over-burdening the land with exhausting crops, 

 they have been alternated with green crops — and 

 that manure has been given in proportion to the 

 products taken off — the' prudent cultivator then 

 sees continue the new fecundity which the lime 

 has brought, without the soil showing any sign of 

 exhaustion. No where has there been complaint 

 made of argillaceous soils being damaged by lime; 

 and the productiveness of light soils is sustained, 

 in every case that the lime was used in compost. 



In America, where the lime of oyster-shells has 

 taken the place of that of magnesian limestone, 

 the complaints of the exhausting effects of lime 

 have ceased. 



Healthiness given to the soil and to the country by 

 calcareous agents.* 



42. The unhealthiness of a country is notcaus- 



*There was no position in the Essay on Calcareous 

 Manures which its author assumed with so much hesi- 



ed by the accumulation of water, nor from soil be- 

 ing covered by water. Places on the borders of 

 water do not become sickly but when the water 

 has quitted some part of the surface which it pre- 

 viously overflowed, and the summer's sun heats 

 the uncovered soil, and causes the decomposition 

 of the remains of all kinds of matter left by the 

 water, and contained in the upper layers of the 

 soil. Thus, ponds are not unhealthy but when 

 drought, by lowering the waters, leaves naked ex- 

 tensive margins, to be acted on by the sun and 

 air. In rainy years, fevers on the borders of ponds 

 are rare. 



Epidemic diseases most often arise on the bor- 

 ders of marshes laid dry — in the neighborhood of 

 mud thrown out of ditches or pits — and in the 

 course of bringing new land into cultivation, 

 where the ploughed soil is for the first time expo- 

 sed to the summer's sun. In the interior of Rome, 

 the vineyards, the gardens are remarkably unheal- 

 thy — while the sickliness disappears where the 

 emanations from the soil arc prevented by build- 

 ings. In the Pontine marshes, they cover the 

 dried parts with water to arrest the danger of their 

 effluvia. It is then from the soil, and not from the 

 waters at its surface, that insalubrious emanations 

 proceed. Waters placed on the surface, always 

 in motion, agitated by every wind, are not altered 

 in quality, and do not become unhealthy: but when- 

 ever they are contained in some place without 

 power to receive exterior influences, or to have 

 motion, they are altered in their odor, taste, and 

 consequently injured in relation to health. 



Whenever water then, without covering the 

 soil, penetrates the upper layer without being able 

 to run through (Ik 1 subsoil, it remains without mo- 

 tion, and stagnant, within the soil — is changed by 

 the summer's sun, serves to hasten the putrefac- 

 tion of the broken down vegetable remains in or 

 on the mould, and the exhalations from the ground 

 become unhealthy. Thus are all drained marshes, 

 of which the suWace only is dry, while the water 

 still penetrates the subsoil — thus, all the margins 

 of rivers which have been covered by recent inun- 

 dations ol* summer, are unhealthy: thus also, (for 

 a great and unhappy example) the argil o-si lie ious 

 plateaux, whenever the closeness of the subsoil 

 does not let the water pass through, produce, in 

 dry years, at the close of summer, emanations 

 which attack the health of the inhabitants. 



43. But this unhappy effect appears almost no 

 where in calcareous regions: the margins of lakes 



tation as the agency of those manures in removing 

 causes of disease. That hesitation did not arise from 

 doubt of the truth of the position — but because of its 

 very high importance, and its entire novelty — its being 

 then sustained but by few known facts furnishing di- 

 rect evidence, and by no known authority whatever of 

 earlier writers. It is therefore the more gratifying to 

 rind in the work now presented, that about the same 

 time, another and far remote investigator of the same 

 subject, by a different course of reasoning, and by dif- 

 ferent proofs, had arrived at precisely the same conclu- 

 sion — and that he maintains even more generally than 

 the former work, the important and sure effects of cal- 

 careous manures in rendering a country more healthy. 

 Ed. Farm. Reg. 



