1837] 



FARMERS' REGISTER. 



MS 



Btaut supply of moisture be triven by irrigation. 

 A small i)orrion ol' clay will much improve light 

 eauils; it takes a large quantity of sand to correct 

 the tenacity of clay. 



Lime, in its pure state, is familiar to every one 

 as the basis of the morJar used la huildinif. Ii is 

 proi'vuced by burning marble, chalk, limestone, or 

 shells, in a great lieat. In the stones which are 

 formed principally of lime, it is cambined'vvith 

 some acid, most generally the carbonic acid, which 

 separates li-om it by the operaiiun of burning, in 

 the form of an air or gas, hence, called fixed air, 

 from its being thus/ix.^a' in a stone. These stones 

 of various degrees ot hardness, are now all class- 

 ed under the name of carbonates of lime. 



Lime unites readily vviili water, which it also 

 absorbs from the atmosphere. It then becomes 

 slaked. By uniting with carboriic acid, it returns 

 to its tbrmer state of carbonate; with this differ- 

 ence, that, unless much water be present, it re- 

 mains a fine impal|)able powder. Pure lime is 

 soluble in water, though sparingly; a pint of water 

 cannot dissolve more than about twenty gr;uns: 

 the carbonate is not soluble in water. Carbonatf^ 

 of lime has a powerllil effect on the fertility of a 

 soil, and no soil is very productive without it. It 

 is consequently used extensively as an improver 

 of the soil, otherwise called a manure ; but its use 

 in this respect, and the mode in which it acts, will 

 be given in the articles ^'manure''' and '■Hhne.'''' 



Carbonate of lime, as an earth, is neither so te- 

 nacious as clay, nor so loose as sand. In propor- 

 tion to the fineness of its particles it approaches to 

 the one or the other, and when the parts are large 

 and hard, it takes the name of limestone gravel. 



Its distinguishing feature, is its solubility in 

 acids, which it neulraiizesj depriving them of their 

 noxious qualitii's in the soil. A proper mixture of 

 these three earths, in a due state ol" meclianical 

 division, Ibrms a soil well fitted to the growth of 

 every species of plants, especially those which 

 are cultivated for Ibod; and nothing more is re- 

 quired than a proper climate as to heat, a proper 

 degree of moisture, and sutFicient nourishment, to 

 make all the plaats generally cultivated thrive 

 most luxuriantly in such a mixture, which is usu- 

 ally called a loam. 



But there are some soils, which, besides a pro- 

 per mechanical texture and mixture of earths, 

 contain a large proportion of a natural manure, 

 which renders them extremely fertile. This is a 

 substance produced by the slow decay of animal 

 land vegetable matter. It can be separated from 

 the other parts ot the soil, and has been accuu- 

 rately analyzed and described by many of the 

 •most experienced chemists, particulaly by Four- 

 <croy, Davy, Chaptal, and Theodore de Saussure. 

 (See ^Recherches Ckimiques siir la Vegetatiun,' 

 Paris, 1804, 8vo.) This substance has been call- 

 ed vegetable mould ; but, as this is not a very dis- 

 tinct term, we shall, after Thear and other eminent 

 writers on agriculture, adopt the name of humus 

 when speaking of it. Humus is a dark, unctu- 

 ous, friable substance, nearly uniform in its ap- 

 pearance. It is a compound of oxygen, hydro- 

 gen, carbon, and nitrogen, which, with the ex- 

 ception of nitrogen, which is (bund only in some 

 substances, are the elements of all animal and ve- 



fetable substances. It is the result of the slow 

 ecompositions of organic matter in the earth, and 

 is found in the greatest abundance in rich garden 



mould, or old neglected dunghills. It varies eome- 

 what in its qualities and composition, according 

 to the substances from which it has been formed, 

 and the circumstances attending their decay. It 

 is the product of organic power, such as cannot be 

 compounded chemically. 



Besides the lour essential elements in its com- 

 position, it also contains other subslunccs in small- 

 er quantities, viz: i)hos!)horic and sulphuric acids 

 combined with some base, and ako earths and 

 sahs. Humus is the product of living matter and 

 the sounie of it. It affords food to organization. 

 Without it, nothing material can liave lili!. The 

 greater the number of living creatures, the more 

 humus is formed; and the more humus, the great- 

 er the supply of nourishment and lili;. Every or- 

 ganic being in life adds to itself the raw materials 

 of nature, and forms humus, which increases as 

 men, animals, and plants increase in any portion 

 of tlie earth. It is diminished by the process of 

 vegetation, and wasted by being carried into the 

 ocean by the waters, or it is carried into the atmos- 

 phere by the agency of the oxygen of the air, which 

 converts it into gaseous matter. (See Thaer. 

 ^Gnmd-saize der Jiationellen Landwirthshaft,^ 

 Berlin, 1810, fhur vols. 4*o.) 



Humus, in the state in which it is usually found 

 in the earth, is not soluble in water and we might 

 have some ditliculty in comprehending- how it en- 

 ters into the minute vessels of the roots of plants; 

 but here the admirable provision of nature may 

 be observed. Humus is insoluble and antiseptic; 

 it resists further decomposition in itselfj and in 

 other substances in contact with it. It remains 

 for a Ions: time iti the earth unimpaired; but no 

 sooner is it brought into contact with the atmos- 

 phere, by the process of cultivation, than an action 

 begins. Part of its carbon uniting with the oxy- 

 gen of the atmosjjhere, produces carbonic acid, 

 which the green parts of plants readily absorb; 

 while its hydrogen, with the same, forms water, 

 without which, plants cannot live; and in very 

 warm climates, where this process goes on more 

 rapidly, the moisture thus produced keeps up ve- 

 getable lii(3, when rains and dews fiiil. The resi- 

 due becomes a soluble extract, and in that state is 

 taken up readily by the fibres of the roots. But 

 the changes still goon; the extract absorbs more 

 oxygen, and becomes once nnore insoluble, in the 

 tbrm of a film, v/hich Fourcroy calls vegetable al- 

 bumen, and which contains a small portion of ni- 

 trogen, readily accounted for. By bringing fi-esh 

 portions of humus to the surface and permitting 

 the access of air to it, more carbonic acid, water, 

 extract, and albumen are formed, and give '-a regu- 

 lar supply to the plants, which, by their living 

 powers, produce the various substances found in 

 the vegetable kingdom of nature. Hence we see 

 the great importance of frequently stirring the 

 surface of the earth between cabbages and other 

 vegetables. 



It is to the patience and perseverance of the che- 

 mists above-named, that we owe this insight into 

 the wonderful process of vegetable growth. What 

 we here state is on their authority. 



We can now readily understifud the great im- 

 portance of humus, and of those rich manures 

 which are readily converted into it, when not im- 

 mediately absorbed by plants. But it has stil Ian- 

 other property, highly important to fertility ; it 

 renders stiff clays porous, and consolidates loose 



