B-OK III. ALTERATION OF THE PARTS OF THE SOIL. 325 



verisation and manure would insure perpetual crops on the same soil ; but they must at the same time 

 have felt, that they had neither the requisite labourers to bestow the cultivation, nor cattle to produce the 

 manure. Hence they would find it easier to break up one piece of fresh ground after another, and after 

 they had gone a round in this way, as extensive as their limits or other circumstances permitted, they 

 would return to where they began. As their limits became circumscribed by the increase of population, 

 or other causes, they would return the oftener, till at last, when property became more rigidly defined, and 

 more valuable, they would return at short intervals regularly. Then it was that the necessity and 

 advantage of working fallows would be felt, and the practice become systematise^ as at the present day, 

 and from the earliest records in civilised countries. The practice of fallowing in Italy, during the time of 

 the Romans (128.), differed in nothing from that of the same country, and of the rest of Europe, at the 

 present day : and if we trace field culture among savage and semibarbarous nations, and gradually through 

 such as are more wealthy and refined, we shall find the fallow in all its gradations, from breaking up at 

 random, to the triennial, quintennial, and septennial operation^ of the best British farmers. 



SuBSECT. 4. Alteration of the constituent Parts of Soils. 



2180. The constituent parts of soils may be altered by the addition or subtraction of in- 

 gredients in which they are deficient or superabound, and by the chemical change of some 

 constituent part or parts by the action of fire. 



2181. hi ascertaining the composition uf faulty soils, ivith a view to their improvement by 

 adding to their constituent parts, any particular ingredient which is the cause of their 

 unproductiveness should be particularly attended to ; if possible, they should be com- 

 pared with fertile soils in the same neighbourhood, and in similar situations, as the 

 difference of the composition may, in many cases, indicate the most proper methods of 

 improvement. If, on washing a sterile soil, it is found to contain the salts of iron, or 

 any acid miatter, it may be ameliorated by the application of quicklime. A soil of good 

 apparent texture, containing sulphate of iron, will be sterile ; but the obvious remedy is 

 a top-dressing with lime, which converts the sulphate into manure. If there be an excess 

 of calcareous matter in the soil, it may be improved by the application of sand or clay. 

 Soils too abundant in sand are benefited by the use of clay, or marl, or vegetable matter. 

 Light sands are often benefited by a dressing of peat, and peats by a dressing of sand ; 

 though the former is in its nature but a temporary improvement. When peats are acid, 

 or contain ferruginous salts, calcareous matter is absolutely necessary in bringing them 

 into cultivation. The best natural soils are those of which the materials have been 

 derived from different strata, which have been minutely divided by air and water, and are 

 intimately blended together ; and in improving soils artificially, the cultivator cannot do 

 better than imitate the processes of nature. The materials necessary for the purpose are 

 seldom far distant ; coarse sand is often found immediately on chalk, and beds of sand 

 and gravel are common below clay. The labour of improving the texture or constitution 

 of the soil is repaid by great permanent advantages ; less manure is required, and its 

 fertility insured ; and capital laid out in this way secures for ever the productiveness, and 

 consequently the value, of the land. 



2182. The removal of superabundant ingredients in soils may sometimes be one of the 

 simplest and most effectual means of their improvement. It occasionally happens that 

 the surface of a well proportioned soil is thickly covered with peat, with drifted sand, 

 with gravel, or with small stones. Extensive examples of the former occur in Stirling- 

 shire, and of the latter in Norfolk. In such cases, a simple and effectual mode of im- 

 provement consists in removing the superincumbent strata, and cultivating that below. 

 This can seldom be put in practice on a large scale, with such heavy materials as gravel 

 or stones ; but some hundreds of acres of rich alluvial soil, deeply covered by peat, have 

 been bared and cultivated in Blair- Drummond moss in Stirlingshire; an operation com- 

 menced by the celebrated Lord Kaimes (Geii. Rep. of Scot., App. v. 5.), copied by his 

 neighbours, and continued by his and their successors. The moss is floated off by 

 streams of water, which empty themselves in the Firth of Forth. In this river, by the 

 winds and tides, it is cast on shore in the bays and recesses, impregnated with salt ; and 

 here it engenders vegetation on the encroaching surfaces of sand and gravel. Coatings 

 of sand or gravel can seldom be removed on a scale of sufficient extent for agriculture, 

 but have, in some instances, for the purposes of gardening. Sometimes this improve- 

 ment may be effected by trenching down the surface, and raising up a stratum of better 

 earth. 



2183. The moss of Kinkardine or Blair- Drummond is situated in the parish of that name not far from 

 Stirling, and contains upwards of 2000 acres, 1500 of which belong to the estate of Blair-Drummond. It 

 lies upon a bed of clay, which is a continuation of the rich alluvial soil which forms the flat vales called 

 Corses of Stirling and Falkirk. This vale or plain had been covered with trees, which appear to have 

 been felled by the Romans, and this, by stagnating the water, ended in producing the moss. This moss 

 consists of three different strata : the first, black and heavy, appears to have been formed of bent grass and 

 fallen trees ; the second is composed principally of Sph^ignura palustre, and is brown and of an elastic 

 texture ; the third is about a foot thick, and consists of heath and a little bent grass. In general these 

 three strata occupy to the depth of seven feet. Lord Kaimes took possession of this moss in 1766, and, 

 soon after, conceived the idea of floating off" the moss into the Firth of Forth, and exposing the alluvial 

 soil for corn culture. After various experiments, which, however interesting, it would occupy too much 

 room to detail, the following may be given as the result. 



2184. Manner of floating off the moss. A stream of water sufficient to turn a common corn-mill will 

 carry off" as much moss as twenty men can throw into it, provided they be stationed at the distance of 100 

 yards from each other. The first step is to make in the clay, alongside of the moss, a drain to convey the 



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