1835;] 



FARMERS' REGISTER 



73 



on the 30th of April, (a dry day) induced to cut 

 and weigh its produce, which I found to he 16 lbs., 

 amounting to the astonishing quantity of thirty- 

 four and a half tons per acre; and that at a period 

 when any other green article fit for soiling was 

 not above two or three inches long. I cut it again 

 the 24th of June and obtained eight lbs.; and 

 again on the 10th of September, when I had ten 

 lbs., (both dry days) making a total from three 

 cuttings, of thirty -four lbs., equal to seventy-three 

 tons per acre." 



A. NICOL. 



From tlie Elements of Jlgriadtwe, by David Low, Prefessor of 

 Agriculture in the University of Edinburgh. 



MANURES. 



All substances which, when mixed with the mat- 

 ter of the soil tend to fertilize it, are, in common 

 language, termed manures. 



Manures may be composed of animal or vege- 

 ble substances; or they may consist of mineral 

 matter; or they may be partly derived from mine- 

 ral and partly from animal and vegetable sub- 

 stances. They may therefore be classed, accord- 

 ing to their origin, into — 



1. Animal and vegetable manures, 



2. Mineral manures, 



3. Mixed manures. 



In describing this class of substances, it is not 

 my design to treat of their chemical mode of ac- 

 tion. This investigation forms one of the most 

 interesting parts or the chemistry of agriculture; 

 but it is not essential to that practical knowledge 

 of the subject which will suffice for the common 

 purposes of the farmer. The remarks to be made 

 therefore, on the mode of action of these bodies, 

 will be of a very general nature. 



1st. Ammal and vegetable manures. — Chemical 

 analysis shows us, that all plants, and all the pro- 

 ducts of plants are resolvable into a small number 

 of simple bodies, in various states of combination. 

 These bodies are — carbon, hydrogen, oxygen, and 

 in smaller quantity, nitrogen or azote. These form 

 the essential constituents of all vegetable sub- 

 stances. But there are likewise formed in plants, 

 though in comparatively minute quantity, certain 

 other bodies, consisting chiefly of the four earths, 

 silica, alumine, lime, and magnesia, of the oxide 

 of iron, and of the alkalies soda and potassa, but 

 chiefly the alkali potassa. 



Now, all these bodies, or the elements of all 

 these bodies, exist in animal and vegetable ma- 

 nures; for these being animal and vegetable sub- 

 stances are resolvable into carbon, hydrogen, ox- 

 ygen, and nitrogen, with the intermixed earthy 

 and other bodies, existing in the living plants. 



In supplying, therefore, animal and vegetable 

 substances to the soil in a decomposing state, we, 

 in truth, supply the same substances which enter 

 into the composition of the living plants. The 

 substances indeed exist in the dead matter of the 

 manures, in states of combination different from 

 those in which they exist in the living vegetable; 

 but still they are present, and must be believed to 

 supply the matter of nutrition which the plants in 

 growing require. Science has made known to us 

 the truth, that the living plants and the dead ma- 

 nures are resolvable into the same elementary sub- 

 stances; but experience has not the lese taught the 

 husbandman in every age, that all animal and ve- 



Vol. Ill— 10 



getable substances, mixed with the matter of the 

 soil, tended to fertilize it, by affording nourish- 

 ment to the plants which it produced. 



The simple bodies which form the substance of 

 manures exist in various states of combination^ 

 and often in the solid state. Now, there is reason 

 to believe, that, in order that these solid matters 

 may be absorbed by the roots of the growing 

 plants, they must be dissolved in water. The ab- 

 sorbing pores of the roots of plants are so minute, 

 that they are only to be discovered by the micro- 

 scope. The solid bodies, therefore, which find 

 their way into these pores, may reasonably be sup- 

 posed to be held in solution by that aqueous mat- 

 ter which enters into the roots of plants, and forma 

 the sap. "Water is apparently the medium by 

 which all the matter of nutrition, in whatever 

 form, is conveyed into the roots of plants, and 

 without which, accordingly, vegetation is never 

 known to take place. 



Holding this opinion to be just, the substances 

 which form vegetable and animal manures, be- 

 fore they can be rendered available, as nutriment 

 to plants, must be rendered soluble in water. 



Of the means which nature employs for this pur- 

 pose, fermentation appears to be the chief. By 

 this process, the elementary parts of the substance 

 fermented assume new forms of combination, and 

 become fitted to supply the matter of nutrition to 

 plants in that form in which it can be received, by 

 the pores of the roots. The fermentative process 

 is completed after the substance to be used as a 

 manure is mixed with the matter of the soil; but 

 it is common also to cause it to undergo a certain 

 degree of fermentation before it is mixed with the 

 earth. This is the method of preparing this class 

 of manures for use, which is emplo) ed in the 

 practice of the farmer. 



Animal matters decompose with facility when 

 acted upon by moisture and the air, the greater 

 proportion of their elementary parts making their 

 escape in various forms of gaseous combination, 

 and leaving the earths, alkalies, and carbonaceous 

 matter remaining. 



When this decomposition takes place beneath 

 the surface of the ground, these gaseous com- 

 pounds, as well as the carbon, (which there is 

 reason to believe assumes also the gaseous state by 

 combining with oxygen,) may be supposed to be 

 partially or wholly retained in the earth to afford 

 the matter of nutrition to the plants. 



Purely animal substances, therefore, which 

 thus readily decompose, do not absolutely require 

 fermentation before they are mixed with the soil. 

 Yet even in the case of purely animal substances, 

 certain beneficial consequences result from sub- 

 jecting them to a previous state of fermentation. 

 Thus the urine of animals, when applied in its 

 recent state to the soil, is not found to act so bene- 

 ficially as a manure, as when a certain degree of 

 previous fermentation has been produced. 



And there is another purpose promoted by 

 causing even pure animal matter to undergo fer- 

 mentation, and this is, that, being mixed with ve- 

 getable matter it promotes the more speedy de- 

 composition of vegetable fibre. 



Vegetable fibreis, under certain circumstances, 

 a slowly decomposing substance. When vegeta- 

 bles are green and full of juices, they readily fer- 

 ment; but when the stems are dried, as in the case 

 of straw and other litter, they decompose with 



