138 HARRIS ON THE TIG. 



simple reason that a ton of clover hay contains more of 

 the valuable constituents of plant-food than a ton of corn. 

 But a ton of pig manure from a corn-fed pig may be, and 

 often is, worth more than a ton of sheep manure from 

 sheep fed on clover hay. The explanation of these appa- 

 rently contradictory statements is this : A ton of corn 

 contains more nutritious matter than a ton of clover. It 

 contains more starch and oil, and these are digested and 

 assimilated by the pig, and consequently there is a less 

 quantity of matter to be voided as excrements. On the 

 other hand, although a ton of clover contains a greater 

 proportion of the more valuable elements of plant-food 

 than a ton of corn, yet the clover does not contain nearly 

 as much nutritious food as the corn. There is a large 

 proportion of crude material that cannot be digested, and 

 this is voided in the excrements ; consequently, we get 

 more manure from the ton of clover hay than from a ton 

 of corn. It is not worth as much, weight for weight, but 

 it is worth more as a whole, because there is more of it. 

 In other words, a ton of pig manure from corn may be 

 worth as much again, as a ton of sheep manure from clo- 

 ver hay ; and, in point of fact, pig manure is ordinarily 

 worth much more per ton than the manure from cows, 

 horses, or sheep. But, at the same time, it is equally true 

 that, if the same food was fed to a sheep that we feed to 

 the pig, the manure of the sheep would be equally valua- 

 ble. Pig manure is usually more valuable, in proportion 

 to its weight or bulk, than ordinary farm-yard manure, 

 because the pigs are fed on more nutritious food, or, in 

 other words, on food containing a less proportion of crude, 

 indigestible matter, and consequently we get less bulk of 

 manure from the pig, but it is more valuable. But it is a 

 grave error to suppose that a pig will make better manure 

 than a sheep, a cow, or a horse. 



The following table, prepared by Mr. Lawes, shows the 

 average composition of different articles of food, together 



