OIL-CAKE. 233 



gredients as to the first, because they are contained 

 in oil-cake in no greater quantity than in barley- 

 straw, oat-straw, etc. 



Respecting the total strength of oil-cake as a ma- 

 nure, and its duration, I am not yet able to adduce 

 such precise figures as those placed at my disposal, 

 by the practical experience of Saxon farmers, in 

 relation to guano, and to some extent, also, in 

 relation to bone-dust; since, notwithstanding nu- 

 merous experiments, that establish the important 

 power of this agerit on the soil, few only have been 

 instituted for the purpose of exact comparison, or 

 prosecuted long enough to enable us to obtain a 

 complete answer to these inquiries. It may be as- 

 sumed to be very near the truth, that the entire oper- 

 ation of 1 cwt. of rape-meal is to be considered equal 

 to that of 18 to 20 cwt. of stable-muck, 1 to 1| cwt. 

 of bone-dust, 1 to 3 cwt. of good guano ; and that 

 1 cwt. of rape-meal is capable of producing in the 

 whole duration of its action 250 to 300 lbs of rye, of 

 which some 50 to 60 per cent, may be placed to its 

 operation in the first year, 20 to 25 per cent, in the 

 second, and 10 to 15 per cent, in the third. 



The oil contained in the cakes, as already men- 

 tioned, contributes nothing to their fertilizing power ; 

 it rather, indeed, detracts from it, in so far as, like fat 

 in fresh bones, it retards their decomposition. The 

 assertion has even been advanced, that the non-germi- 

 nation of seeds, which is occasionally remarked when 

 they are introduced into the earth at the same time 

 20* 



