VEGETABLES. 



gree capable of being diflblved in water, though the exter- 

 nal coats or coverings of living plants, principally on account 

 of the relinous material that enters into their compoiition, are 

 preferved from its aftion and effetts. It is plain, that in 

 confequence of the firft of thefe circumilaiices, and that of 

 earthy matters being contained in them, which had been 

 taken up in the ftate of folution or diffufion with their frefh 

 fluids orjuices while growing, that confiderable quantities of 

 vegetable earth or mould mull be continually formed and de- 

 pofited on lands by the natural diffblution and decay of fuch 

 bodies. But its formation and provifion are much more 

 abundantly effefted by means of the putrefaftion and de- 

 ftruftion of fuch vegetable produftions as are cut down, or 

 otherwife deftroyed, on the furface of the land, and the lay- 

 ' ing of different kinds of manures and compoft materials upon 

 It. In cales where thefe have been in great abundance for a 

 long time, there is moftly, it is faid, a deep rich furface 

 bed of this earth or mould ; but that where few vegetable 

 produdts, and thofe of the lefs luxuriant kind, have been 

 left to undergo the above procefles, or little aflillance given 

 by means of manures, the cruft of furface earth or mould is 

 commonly very thin and poor. In all cafes, it is evident 

 that the dilTolution and decay of vegetable materials mud be 

 greatly promoted and expedited by a proper degree of moif- 

 ture, and fuitable ftate of heat ; the atmofphere being at the 

 fame time in a proper condition for the purpofe. The clofe 

 and ftagnated ftate of different forts of luxuriant tall 

 growing crops of the grafs, herb, plant, or other kinds, 

 nave likewifc much effeft in the forming and elaborating of 

 this mouldy material, by the decaying foliage thereby pro- 

 moted, falling down and being fo much depofited on the 

 land. 



All thefe materials, during the ftate of decay, undergo 

 different changes in their cOnftituent principles or parts ; 

 the water which they contain being decompounded, pure air 

 or oxygen is abforbed, heat difengaged, and new compofi- 

 tions of the aerial and fahne kinds formed ; by which means 

 a number of matters are prepared and fitted for the ufe and 

 fupportof vegetable life, which could not have been fupphed 

 in any other way, as well as rendered much more extenfively 

 applicable in this intention than they could otherwife poflibly 

 have been. 



It is advifed, that in order to promote the formation and 

 produftion of vegetable earth or mould, recourle fhould be 

 had not only to fuch fubftances as accelerate the putrefaftive 

 procefs, but alfo to fuch as have a tendency to incrcafe the 

 folubility of the vegetable earth or mould of the land itfclf : 

 and that the firft of thefe purpofes may be promoted and at- 

 tained by the application of fuch fubftances and materials as 

 have been found ufeful in changing vegetable matters into the 

 ftate of mucilage, fuch as the carbonate of hme, or effete 

 hme, marie, chalk, and calcareous matters in general, and 

 likewife fome earthy fahne fubftances, as the refufe of fait 

 manufaftories, and others of that kind. That the latter of 

 fuch intentions is to be attempted by the ufe of different fub- 

 ftances and matters that are of an alkaline nature ; fuch as 

 the afties produced by the burning of various green vegetable 

 materials, the urine of animals, the hquor of dung-hills and 

 pits, night-foil, and many other fuch animalized matters and 

 fubftances. There are many other ways, too, in which ve- 

 getable earth or mould may be made and rendered more 

 abundant in land ; fuch as the frequent growth of thofe 

 kinds of crops that cover the ground in a clofe full manner, 

 fo as to produce a confined ftate of the air, as already fug- 

 gefted ; the confuming upon, or turning down into the 

 ground, full, rich, and fucculent green crops, by which 

 much vegetable matter is brought into a ftate of decay ; and 

 Vol. XXXVI. 



by the caufing of the deftruftion and evacuation of infefts of 

 various forts, which are predominant in land, by the ufe and 

 application of fuch fubftances and matters as have the power 

 of effecting thefe different purpofes and intentions. 



It muft be noticed, however, that it has been remarked 

 by the writer t)f the work on the " Conneftion of Agricul- 

 ture withChemiftry," that too large a proportion of vegetable 

 matter in land, particularly where it is expofed to be much 

 afted upon by the oxygene principle of the atmofphere, is 

 liable to render the ground too loofe and open in its nature 

 for the growth of moft forts of crops of the grain kind ; 

 winter corns being, efpecially from the fudden alternations 

 of froft and thaw, frequently thrown out of fuch lands, and 

 almoft wholly deftroyed. In cafes of this nature, great ad- 

 vantage may, it is faid, be derived from the ufe of different 

 matters of the faline kind, and lime in its faturated ftate, as 

 by fuch means the vegetable parts of the land will be brought 

 to their moft proper and produftivc ftate, in fo far as the 

 growth of crops is concerned. 



It has been conceived too by the fame writer, that the ab- 

 forption of the oxygene principle from the furrounding at- 

 mofphere, or what is termed the procefs of oxygenation, is 

 the principal caufe of the retention of vegetable matter on 

 the furface of the earth, in deep peaty lands as well as others, 

 but efpecially in fuch as have been long in a ftate of tillage, 

 or under the plough. This procefs having the power, it is 

 fuppofed, of rendering the vegetable matter lefs deftruftible, 

 fcarcely any of it being carried away in a ftate of diffolution 

 by rains, or water in other ways, an accumulation takes 

 place, which, under other circnmftances, could not have 

 happened. The indeftruftible ftate of vegetable matters 

 under thefe circumftances, and their conftant accretion, may, 

 it is thought, be referred to the infoluble compounds pro- 

 duced by the aftion of pure air on fuch inflammable fub- 

 ftances. The infolubility, to a certain degree, of this fyf- 

 tem adopted by nature, is undoubtedly, it is fuppofed, to 

 be preferred to one more completely foluble ; for it is evi- 

 dent, it is faid, that if putrefaftion or oxygenation had pof- 

 feffed the power of rendering all the vegetable matter, by a 

 fpeedy procefs, foluble in water, two pernicious confequences 

 muft have followed : the rains would have walhed down fuch 

 extrafts, and foluble matters, as faft as formed, into the 

 rivers and fprings, contamniating the waters, and rendering 

 them unfit for the exiftence of fiflies, or for the ufe of ter- 

 reftrial animals. The fea in procefs of time would thereby 

 receive all the vegetable and animal produce of the dry land, 

 and the earth would ultimately become barren, confifting 

 alone of the fimple earths, without any admixture of ve- 

 getable matter ; confequently there could be no accumulation 

 of this fubftance on the furface, as is the cafe to an immenfe 

 degree at prefent. As fuch, there cannot, it is conceived, 

 be a doubt, but that the prefent incomplete procefs of pu- 

 trefadtioii, oxygenation, or folution ot organic bodies, has 

 been eftabhftied by the great Creator of all things for wife 

 and benevolent purpofes ; efpecially when it ftiall be under- 

 ftood, that the apparent imperfeftions of this, to a certain 

 degree, infoluble fyftem, are, as they refpeft agriculture 

 and vegetation, to be remedied, when neceffary, by the in- 

 genuity and induftry of man. It is confequently fuppofed 

 that the vegetable matters which exift in lands, from their 

 admitting different degrees of this procefs, and, of courfe, 

 becoming more or lefs infoluble, have different powers in 

 forwarding the growth and fupport of plants. Where the 

 expofure to thefe caufes has been long, they are generally 

 more infoluble in their nature than where the contrary has 

 been the cafe. See Oxygenation. 



Upon the whole, vegetable earth or mould Ibould be aceu- 

 4 R mulated 



