92 On the Inorganic Constituents of Plants. 



As has already been stated, the series of practical experi- 

 ments in these crops were undertaken with a chemical object in 

 view ; it is almost unnecessary to observe, that the relative quan- 

 tity of produce obtained by each manure, was a matter of com- 

 paratively secondary importance ; the main object was to connect 

 changes in chemical composition, or quality, with the action and 

 absorption of inorganic manures. In attaining these objects, 

 the richness or variable composition of the soil, exerts little influ- 

 ence, though in judging of the relative practical effects of the 

 manures employed, it causes such irregularities and discrepancies, 

 as to take from the results all pretensions to rigid accuracy in that 

 respect. Very marked differences were produced in the plants 

 experimented on, by the salts applied; and it now remains to 

 investigate the quality and nature of the substances absorbed by 

 the different crops thus manured. The result of that investigation 

 will be the subject of a future communication to the Society. 



38, Bedford Row, 

 Jan. 10, 1844. 



