PRODUCE FKOM GUANO AND BONE-DUST. 



265 



The 411 Ibs. guano contained 53, and the total pro- 

 duce 271 Ibs. of nitrogen, or very nearly five times 

 more. The bone-dust contained 37 Ibs. of nitrogen, 

 whereas in the total produce there were 342 Ibs., or 

 nearly nine times more. The bone-dust gave in the 

 crops altogether 71 Ibs. of nitrogen more than the guano. 

 Between the quantity of nitrogen in the manure and 

 the amount of the crops reaped, there is, therefore, no 

 connection whatever. 



In the Saxon experiments, the plots manured with 

 bone-dust gave the following results : 

 Manuring with tone-dust. 



Increase of produce over the unmanured field (see p. 186). 



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