es are powerful fertilisers of the soil; but the three
principles which constitute their manurial value--namely, nitrogen
(ammonia), phosphoric acid, and potash--are purchasable at far lower
prices in guano and other manures. Nevertheless, many farmers believe
that the most economical way to produce good manure is to feed their
stock with concentrated aliment, in order to greatly increase the value
of their excreta. They consider that a pound's worth of oil-cake, or of
corn, will produce at least a pound's worth of meat, and that the manure
will be had for nothing, or, rather, will be the profit of the business.
The richer food is in nitrogen and phosphoric acid, the more valuable
will be the manure it yields. It follows, therefore, that if two kinds
of feeding stuff produce equal amounts of meat, that the preference
should be given to that which contains the more nitrogen and phosphoric
acid. Mr. Lawes, who has thrown light upon this point, as well as upon
so many others, has made careful estimates of the value of the manure
produced from different foods. They are given in the following table:--

TABLE

Showing the estimated value of the manure obtained on the
consumption of one ton of different articles of food; each
supposed to be of good quality of its kind.

Estimated Money Value
Description of Food. of the Manure from
One Ton of each Food.

1. Decorticated cotton-seed cake L6 10 0
2. Rape-cake 4 18 0
3. Linseed-cake 4 12 0
4. Malt-dust 4 5 0
5. Lentils 3 17 0
6. Linseed 3 13 0
7. Tares 3 13 6
8. Beans 3 13 6
9. Peas 3 2 6
10. Locust beans 1 2 6(?)
11. Oats 1 14 6
12. Wheat 1 13 0
13. Indian corn 1 11 6
14. Malt 1 11 6
15. Barley 1 9 6
16. Clover-hay