DISEASES "CLOVER SICKNESS." 



113 



Mr. Berkeley's opinion, that " it seems quite preposterous 

 to believe that clover will not succeed once in a four-years' 

 course, from mere exhaustion of the soil/' 



Dr. Anderson's investigations were made in reference to 

 a field at Craiglockart, on a particular part of which Red 

 clover always succeeded, though it failed on the adjoining 

 portions, and even when it did not fail altogether, the 

 crop on this particular part invariably presented a remark- 

 able superiority, in strength of plant and abundance, to 

 that on the remainder of the field. This difference was 

 traced distinctly to a sort of shale, which formed the main 

 proportion of the soil where the clover succeeded, which 

 had been thrown out of an old quarry in the corner of the 

 field ; the same luxuriance of growth had also been noticed 

 in a shale of precisely similar character in Fife. Every 

 precaution was taken to obtain a fair sample of the soil 

 (page 84, vol. i.), its examination was conducted with great 

 care, and with the following results: 



The only difference worthy of remark between the two 

 analyses exists in the reduced proportions of sulphuric 

 acid and lirne in the soil which has been under clover 

 cultivation, both of which substances appear to be es- 

 sential to the healthy development of the plant. In 

 some analyses of other soils on portions of which clover 



