MANURE VALUES OF CATTLE FOODS 257 



The compensation table they drew up showed (1) the 

 amount of nitrogen, phosphoric acid, and potash in the food 

 itself; (2) the amount passed by the animal after taking out 

 what it required for its own fattening increase ; (3) the value of 

 this voided material at the current prices of these constituents 

 in manures, or as they called it, the " original manure value " of 

 the food. They then proceeded to arrange a compensation 

 table on the basis of allowing the outgoing tenant half this 

 original manure value, i.e., assuming that only half of the 

 manure material voided by the animal would be found by the 

 incoming tenant in the manure heap he was taking over. This 

 compensation value was further diminished by one-third for 

 each additional year between the date when the food was con- 

 sumed and the expiration of the tenancy ; thus the compensation 

 value of food consumed in the last year of the tenancy would 

 be half of the original manure value, and it would become 

 one-half less one-third of itself (or one-third of the original 

 manure value) for food consumed in the second year before 

 the tenancy ended, and so on by steps of one-third less for 

 each earlier year. These tables were based on the composition 

 of the fattening increase as ascertained in the previous experi- 

 ments. Other tables were drawn up for milch cows, which 

 take a much greater toll of the food consumed. 



These compensation tables never passed into general use, 

 partly because of the somewhat complex character of the 

 argument and the long period previous to the expiration of the 

 tenancy over which they allowed compensation to be claimed 

 for the consumption of purchase food. They have, however, 

 brought into prominence the great errors introduced by the 

 common custom of paying half the purchase price of the food 

 consumed during the last year only of the tenancy, since the 

 manure value of a food is quite independent of its food value 

 .and price in the market. Decorticated cotton cake, for example, 

 has the highest manure value of any substance commonly used 

 for food, yet it can be purchased more cheaply than linseed cake, 



which has a much lower manure value. Maize, again, however 



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