39 



stone soils is very variable ; some require pressing for wheat, 

 others do not ; some contain 5 per cent, of alumina, others 

 not 1 per cent. ; some 12 per cent, of lime, others not 2 per 

 cent. ; hence, upon the more compact, the clover will stand the 

 winter, while upon other portions it will not do so. 



6. It explains why, in the south of England, a working 

 flock of sheep is of so much value ; — ^because by their treading 

 they give great solidity to the soil, and also a capacity to the 

 clovers upon it to resist sudden changes of temperature. 



7. It explains why claying or marling clover-sick lands, as 

 mentioned by Mr. Morton (page 77, Agricultural Report^) 

 should in Norfolk be a sufficient remedy ; — because clay and 

 marl give tenacity to the soil, and the power before men- 

 tioned. 



8. It explains why lime is called the mother of seeds to 

 certain soils ; — because this earth is one-half of the value of 

 clay in giving tenacity to soil. ( See page 185, Journal of 

 Royal Agricultural Society of England, for 1839, part II.) 



9. It explains, for the same reason, why chalking upon the 

 Yorkshire Wolds is of so much value to the clover crops ; 

 indeed, by walking over these lands it may at once be told 

 whether the land has received this operation by the firm 

 sensation conveyed through the feet. 



10. Lastly, it explains the failure of the numerous trials of 

 the growth of the Trifolium incarnatum (the scarlet clover,) 

 which would be an invaluable plant, but it invariably dies 

 in winter if sown upon land recently ploughed ; while, if the 

 stubble land before sowing be simply scratched by light har- 

 rows, and after sowing compressed with a heavy roller, it 

 will stand the winter. 



Sprengel remarks that the clovers delight in a close 

 topped soil, or one which admits no great quantity of oxygen 

 to the roots. The best clover grown in Great Britain is upon 

 the warp soil in Marsh-land near the river Humber, for not 



