OIL-CAKE. 235 



their nitrogen must be acknowledged to be the most 

 important constituent of oil-cakes ; inasmuch as it is 

 the substance which converts them into an invigor- 

 ating, or flesh-producing food, whilst their oil, on the 

 other hand, occasions a most abundant production 

 of fat or suet (page 82). 



The following calculation may show how great is 

 the advantage which the farmer may derive from the 

 use of oil-cake as a subsidiary fodder. From the 

 results of experiments made in England, it may be 

 regarded as a proposition which is generally true, 

 that, of 5 lbs. of nitrogen contained in provender, 

 1 lb. in fattening animals is converted into flesh, 

 whilst the remaining 4 lbs. pass in great part into 

 the excrements, and that from the 1 lb. of assimilat- 

 ed nitrogen, at least 25 lbs. of flesh are produced. 

 Of 4| lbs. of nitrogen, which, upon an average, are 

 contained in 100 lbs. of oil-cake. 



About ^ lb., value Os. 6c?., is lost by breathing and exhalation. 



« 5 " " 8s. 6d.^ are converted into flesh. 



(c 31 « (c 2s. 8c?., remain in the excrements. 

 The value realized from 100 lbs. of oil-cake must accordingly, on this 



supposition, be estimated at lis. 2d. 



Should a still lower calculation be preferred, the 

 pecuniary return acquired from feeding with oil-cake 

 may be computed at 9^. at the lowest, which is 

 nearly double its cost, and from one fourth to one 

 third more than when it is employed directly for 

 manuring. In foddering cows, it may be assumed 

 that 120 lbs. of milk (in round numbers 60 Saxon 



