184 Progress of Agricultural Knowledge 



chanically by loosening the clay, for its application renders these 

 hills more mellow to work with the plough/'' Chalk, I find, is 

 also used largely on the wolds or chalk-hills of Yorkshire, and 

 there it is found to render loose soils more firm.f This is a very 

 cheap mode of transposing soils ; but on the coast of Essex, where 

 chalking, as Mr. C. Johnson ;]: tells us, is largely practised, it is 

 brought by sea from Kent, and is applied at a rate of from 10 to 

 30 tons per acre, the poor lands requhing more than the rich ; 

 and in the clay districts of Windsor Forest the farmers some- 

 times bring chalk a distance of 10 miles for the same purpose, 

 at an expense, as Mr. Rham has told me in his own case, of 

 8/. per acre. If it is carted 10 miles, where it costs 8/., certainly 

 not an acre of the hills themselves on which the chalk will act 

 should remain without it, where it can be spread from wheel- 

 barrows for little more than 21. The chalk-hills occupy a large 

 tract in England, but whether the soil be generally so strong or 

 so light as to be benefited by chalking I do not venture to say ; we 

 want information on this point also. I have brought forward these 

 cases of admixture of soil, not imagining that a sudden trans- 

 formation of English soils can be effected at once, but in the 

 hope that, in districts where any such practice is known to be 

 beneficial, as on the fens of Lincolnshire or the hills of Hamp- 

 shire, it may be applied with increased spirit; that some of 

 these practices, as that of claying or marling, may turn out to be 

 useful in districts where they are not hitherto known ; that men 

 of science may explain the action of these materials, and so some 

 light be thrown on the laws of vegetation ; and that possibly, as 

 in the case of the overturned load of craig, practical farmers, by 

 observing any casual difference in the verdure or growth of their 

 crops, — for nature or chance are constantly making such experi- 

 ments, if our eyes were open to mark the effect, or our minds to 

 inquire for the causes, — may be so fortunate as to find some new 

 application of the same principle. There are many other cases 

 in point, such as the use of the honeycomb-stone § (the lava 

 of ancient volcanoes) as a manure in Devonshire and Scotland, or 

 of peat upon clay-lands || in Germany and Sweden: those which 

 have been mentioned are enough to show that in this, as in many 



* Mr, Thorpe's paper in the present Number. 



t This opposite effect of chalk, in loosening Hampshire soils and binding 

 those of Yorkshire, may be explained, I think, as foUows :— The chalk, which 

 is hme, mixes with the Hampshire clay, and, expanding? in a different pro- 

 portion during frost, shakes the texture of the soiL On the Yorkshire soil 

 it falls also to powder, and this powder interposed between the coarse par- 

 ticles of soil gives compactness. Mr. Schweizer, of Brighton, has also dis- 

 covered phosphate of lime in chalk. 



+ Mr. C.Johnson on Fertilizers, p. 2G2. ^ Journal, vol, iii. p. C7. 



II The present Number, Mr. Ilandley's papor. 



