4 The Value of Soil Analyses to the Farmer. 



figures. Moreover, these figures are independent of the per- 

 sonal equation and of the climate, which so greatly affects the 

 impression a soil gives ; for example, soils that are described as 

 heavy clays in Scotland, on analysis prove to be similar in all 

 respects to others regarded as free working loams in the south 

 of England. This difference in nomenclature is partly due to 

 the climate which keeps the soil so much wetter in Scotland, 

 where also no really heavy clays such as the London or Oxford 

 clays exist for comparison. But though the mechanical analysis 

 of a soil gives at once a good deal of information as to its 

 behaviour under cultivation, it takes us little further than the 

 chemical analysis towards the solution of the sort of problem 

 indicated at the opening of this article — why a given soil does 

 not answer for a particular crop and how can it be ameliorated. 

 "We have only defined one more factor in a very complex result, 

 and even that factor can only be interpreted by comparative, 

 and not by a jn'iori methods. In other words, we cannot say 

 that a soil with a given composition and structure must behave 

 in such a way, we can only say that one soil resembles in such 

 characteristics as we determine another soil whose properties 

 in practice have been found to be so and so. 



The next step in the study of soils is to accumulate a very 

 large number of analyses of soils whose behaviour in practice 

 is well known, and set down against the analyses that sort of 

 intimate personal knowledge of the character of the soil in wet 

 or dry weather, and the precautions necessary to get a good 

 seed bed on it, &c., which is the special property of an old 

 ploughman who has long worked on the land in question. 



As soon as such a large body of soil analysis data are 

 examined, certain general conclusions can be drawn which 

 bring us a little nearer our prime object — that of being able to 

 give the working farmer information of value. In the first place 

 we find that by the similarity of their mechanical analysis we 

 can group together all the soils which we otherwise know to 

 belong to the same type. For example, in dealing with the soil of 

 the south-east of England, the brick earths, whether occurring 

 by the mouth of the Thames, in the Stour Valley in Kent, or on 

 the maritime plain of West Sussex, all show the same distinctive 

 structure containing about 12 per cent, of clay, little or no 

 coarse sand, and about 2.5 per cent, of fine sand, so that we are 

 justified in claiming that these soils of similar origin constitute 

 a " type." Now the chemical analysis of these same soils 

 neither distinguishes them from others, nor brings them into 

 one characteristic group ; in composition they differ as much 

 among themselves as they differ from other soils of entirely 

 unrelated origin. For example, in nine cases the average 

 percentage of phosphoric acid was 0*16 per cent., but in one 



