_Blood_ is rarely applied to the land directly—though, like the other parts of animals, it makes an excellent compost. As it comes from the sugar refineries, however, in which, with lime water and animal charcoal, it is employed for the refining of sugar, it has obtained a very extensive employment, especially in the south of France. This animal black, or _animalized charcoal_, as it is sometimes called, contains about twenty per cent. of blood, and has risen to such a price in France, that the sugar refiners actually sell it for more than the unmixed blood and animal charcoal originally cost them. This has given rise to the manufacture of artificial mixtures of charcoal, fecal matters, and blood, which are also sold under the name of animalized charcoal. The only disadvantage attending these artificial preparations is, that they are liable to be adulterated, or, for cheapness, prepared in a less efficient manner. _Horn_, _hair_, and _wool_, depend for their efficacy precisely on the same principles as the blood and flesh of animals. They differ chiefly in this, that they are _dry_, while blood and flesh contain 80 to 90 per cent. of their weight of water. Hence, a ton of horn shavings, of hair, or of dry woollen rags, ought to enrich the soil as much as ten tons of blood. In consequence, however, of their dryness, the horn and wool decompose much more slowly than the blood. Hence, the effect of soft animal matters is more immediate and apparent, that of hard and dry substances less visible, but continuing for a much longer period of time. _Bones_, again, while they resemble horn in being dry, differ from it in containing, besides the animal matter, a large quantity of earthy matter also, and hence they introduce a new agent to aid their effect upon the soil. Thus, the bones of the cow consist of 100 lbs. of Phosphate of lime, 55½ Phosphate of magnesia, 3 Soda and common salt, 3½ Carbonate of lime, 3¾ Fluoride of calcium, 1 Gelatine (the substance of _horn_), 33¼ ------- 100 While 100 lbs. of bone-dust, therefore, add to the soil as much _organic_ animal matter as 33 lbs. of horn, or as 300 or 400 lbs. of blood or flesh, they add, at the same time, much _inorganic_ matter—lime, magnesia, soda, common salt, and phosphoric acid (in the phosphates),—all of which, as we have seen, must be present in a fertile soil, since the plants require a certain supply of them all at every period of their growth. These substances, like the inorganic matter of plants, may remain in the soil, and may exert a beneficial action upon vegetation after all the organic or gelatinous matter has decayed and disappeared. From what is above stated, therefore, the reader will gather these general conclusions: