EXPLANATION OF THE FAILURE OF CLOVER. 163 



to discover any explanation, which, in tlieir opinion, they 

 surely must have done, had it been possible to fnid 

 one, they coolly ask us to believe that there are, among 

 the higher classes of plants, certain species bearing about 

 the same relation to other species as the carnivorous to 

 the graminivorous animals ; and as the former feed upon 

 complex organic compounds prepared in the bodies of 

 the latter, so it is, also, with the clover plant ; like mush- 

 rooms, it represents the carnivorous order in the vege- 

 table kingdom. 



It is hardly wortli while to take any notice of this ex- 

 planation ; but it might still prove useful to inquire 

 whether, apart from all consideration of the absorptive 

 power of the soil, Messrs. Lawes and Gilbert have really 

 exhausted all the means that might have been employed 

 to restore the productiveness of the clover-sick field for 

 clover, so as to be justified in giving it as their opinion 

 that when land is clover-sick, none of the ordinary 

 manures, artificial or natural, can be rehed upon to secm^e 

 a crop. 



We may ask why Messrs. Lawes and Gilbert did not, 

 instead of superphosphate of hme, try bone ash, the action 

 of which extends much deeper than that of the super- 

 phospliate; and why sulphate of potash and sulphates 

 alone were emphjyed ? It is not impossilole that common 

 wood ashes might have proved more effective than sul- 

 phate of potash ; and, above aU, chloride of potassium 

 ought to have been tried, which, as an ingredient of liquid 

 manure, is more useful to clover than any other of the 

 potash salts. It is cdso difficult to understand why liquid 

 maniure was not employed, and wliy chloride of sodium 

 was excluded from tlie list of manurinjjf agents. If we 

 consider what Messrs. Lawes and Gilbert omitted to do in 

 their endeavour to solve the problem, and what they 



