332 



FARMERS' REGISTER, 



embraced in if, and not be convinced that i!s so- 

 lution is a matter of no common d.fPjculiy; or 

 doubt that there is here a field opened, m which 

 the best powers of the human mind, and the 

 greatest amount orinlbrmation which can possibly 

 be brought to bear upon the sul)iect, may most 

 properly and most protilably be em|)loyed. 



But to leave these general considerations, and to 

 descend to particulars. What departments ci' hu- 

 man knowledge are there, which admit of an 

 immediate and practical application to the business 

 ol'lhe liirmer? Answering this question, the first 

 which claims attention is chemistry, or that branch 

 oC physical science which investigates the com- 

 posiiion and intimate nature ol' bodies. This 

 claims attention lirst on account of the manner as 

 well as ol'lhe variety of the ajiplicalions of which 

 it adnnis. 



It is certain that there are great diflerences 

 among soils, in their adaptation to agricultural 

 purposes. In one soil, it is necessary only to bury 

 the. seed, and almost without attention, it springs 

 up, and in due season yields an abundant harvest; 

 whilst in another, it is with the utmost ditticuity 

 wo can obtain even a scanty return lor our labors. 

 There arc great diderenccs among soils, in their 

 fitness for the cultivation of dilfereni crops. A soil 

 which will yield an abundant harvest when culti- 

 vated in one crop, will not repay the expense of 

 planting in another. — That these differences arise 

 almost entirely li-om differences in the composition 

 of soils, I suppose, no one doubts. A soil may be 

 rendered unfit lor the cultivation of a certain crop, 

 either by a deficiency in some element necessary 

 lor its growth, or by containing some element 

 which is positively injurious. In order that a ftirni- 

 er may go to work intelligently to remove the 

 difficulty thus presented, he must first know whe- 

 Jher the evil in question consists in the presence of 

 some noxious substance, or in the absence of some 

 necessary one; and then he must determine the 

 precise nature of the substance io be removed or 

 supplied. This he can seldom or never do, by 

 mere inspection, lor the simple reason, that the 

 elements of soils are so intimately intermixed 

 that it is impossible to distinguish them by the 

 senses. 



13ut let us suppose that the nature of the evil is 

 known and that it consists in the presence of some 

 noxious substance ; is he then any belter oil ? It 

 is in vain to think of any mechanical means for us 

 removal, for so intimately is it intermixed with the 

 other constituenis of the soil, that a resort to any 

 such means must result in entire lailuro. In sucn 

 circumstances a knowledge of chemical principles 

 may be of ilie highest value, since Irom them, and 

 from them alone can we learn, liovv the evil is to 

 be removed. In Davy's Agricultural Chemistry, 

 th-ereis an instance mentioned, which wdl fully 

 illustrate this point. " A soil of good apparent 

 texture, from Lincolnshire, waspulmlu my hands 

 by Sir Joseph -Banks, as remarkable lor sterility. 

 On examining it, I Ibund that. iL contained sul- 

 phate of the oxide of iron, and I ofi'ered the ob- 

 vious remedy of atop-dressing with lime, which 

 converts the sulphate into a manure." In this 

 case there are several things worthy of remark. 

 1st, the soil was, to all appearance, a good one, 

 the cause of all its sterility being so intimately in- 

 termixed with the other constituents of the soil, as 

 to be perfectly undislifiguiehable by the senses. 



2n(l, the sulphate of the oside of iron was a sub- 

 stance of such a nature, and existed in such a Ibrro, 

 as to render it altogether impossible to remove it by 

 any other than chentical means ; — as it was so inti- 

 matelyintermixed with the otherelemenis ol ihesoil 

 as to be undistinguishabie by the eye, any atiempS 

 to |)ick it out, vvouKI be entirely out of the question. 

 3d, by the a()plication of chemical principles, Davy 

 was enabled not only to delect the nature of ih-e 

 evil, but Io convert it into a positive benefit. By 

 the action of the lime spread upon the land, the 

 sulphate of the oxide of iron was decomposed ; the 

 oxide of iron, a perfectly inert substance so liir as 

 vegetation was concerned, being left in the soil, 

 whilst the sulphuric acid combined with the lime, 

 thus forming sulphate of lime or plaster, a most 

 excellent matmre. 4lh, the means by which 

 Davy arrived at a knowledge of liie nature of the 

 evil, and the remedy to be applied, were exceed- 

 ingly simple. It is true that these means are no-t 

 mentioned in his accounis of the case ; but all that 

 was necessary, was to lake a small portion of the 

 soil, and having pluced it in a glass, to pour some 

 water over it, and then, aiterit had stood lor ti 

 lew minutes, to add a lew drops of an infusion of 

 nut-galls. VVhen thus treated, the sulphate oi" 

 the oxide ol iron would die-cover iisellj by the deep 

 black color which it would give to the liquid. la 

 such a case as this, the advantages resulting Iroiu 

 a knowledge ol chemistry must be apparent to every 

 one. 



In most instances, sterility arises from the absence 

 of some one or more of the elements ol a good 

 soil, and it is to the interest of the larmer, by the 

 application of a j)roper manure, to sup|)ly this defi- 

 ciency. That It is not always the same element 

 which is absent, is evident fioin the laci, that a 

 manure which will prove very beneficial to one 

 portion of land, will be entirely useless, and evea 

 in some inslances, positively detrimental to an- 

 other. Putrescent vegetable matter and common 

 Ball are two of the manures in common use in 

 England. Some soils are unproductive for the 

 very reason that they contain loo much vegetable 

 matter, and others are so because they coniain loo 

 much sail. To a[)ply vegetable matter to the first, 

 or salt to the last, would be worse than useless ; 

 and yet it does not admit of question, that in most 

 cases, each of these substances is a manure of 

 great value. But I su|)pose that it is not neces- 

 sary to urge the matter further. Every larmer 

 knows, that there is no one manure whlcli will act 

 well on every kind of soil ; and every one, I pre- 

 sutne, will admit, that th;s difi'erence arises almost 

 entirely from difi'erences in the composition of soils. 

 If this be admitted, then the conclusion necessarily 

 follows, that to apply manure lo advantage to any 

 soil, we must first know the particular naiure of 

 ihat soil; and this can be asceriaineil in no other 

 way so well as by chemical analysis. 



The most common ©Ijection which is made, 

 when the claims of cliem;stry upon the practical 

 agriculturist are urged, is based upon the complex- 

 ity of chemical operations, and iheddticuliy ol per- 

 Ibrming chemical analysis. In answer to this, I 

 will say, that whilst it must be admitted that the 

 accurate analysis of soils and minerals is a work 

 of great difficulty, and such as none but the ac- 

 complished chemist, with a well furnished labora- 

 tory at command, can hope to perlorm, yet the 

 difKculiy is an imaginary and not a real one, as 



