( V 



CAUSE OF THE FAILURE OF CLOVER. 161 



selves. They say, page 17, ' Before we enter upon the 

 probable causes of the failure in clover, it may be well 

 to give the results of some experiments conducted in 

 the kitchen-garden at Kothamstead. The soil was in 

 ordinary garden cultivation, and has probably been so 

 for two or three centuries. Early in 1854, the s^th 

 of an acre (about 9f square yards) was measured off 

 and sown with red clover on March 29. From that 

 time to the end of 1859 fourteen cuttings have been 

 taken without any resowing of seed. In 1856 this little 

 plot was divided into three equal portions, of which one 

 was manured with gypsum, another with sulphates of 

 potash, soda, and magnesia, and superphosphate of 

 lime.' 



' The estimated total amount of green clover ob- 

 taied from this garden soil in six years, without further 

 manure, is about 126 tons per acre, equal to about 26-J 

 tons of hay. In four years the increase by the use of 

 gypsum amounted to 15-J- tons of green clover. The 

 increase in the four years by the use of the alkalis and 

 phosphate is estimated to amount to 28f tons of green 

 produce.' 



4 It is worthy of remark,' continues the report, c that 

 it was in some of the very same seasons in which these 

 heavy crops of clover were obtained from the garden 

 soil, that we entirely failed to get anything like a mod- 

 erate crop of clover in the experimental field, only a 

 few hundred yards distant.' 



It is, indeed, most worthy of remark, that upon the 

 experimental field the earth was poisoned by the vege- 

 tation of the clover, so as to render it incapable of fur- 

 ther bearing this plant ; while, at the very same time, 

 under like climatic conditions, the self-same clover-plant 

 engendered no poison in the rich garden soil. 



A comparative examination of the garden and of the 

 field-soil seems never to have been thought of, since the 

 two agricultural chemists were, as we before remarked, 

 in search of an efficient manure, not of the cause of the 

 failure of the plant. But though they have not found 

 the smallest shred of a fact which might serve in any 



