It has been ascertained by accurate experiments made chiefly on man, that muscular exertion is one of the most important causes of the waste of the tissues, and of increased respiratory activity. We cannot move a limb without producing a corresponding consumption of matters already laid up within the body; and it has also been found, that the difference in the quantity of carbonic acid expired during rest and active exertion, is very large. The inference to be drawn from this is, that when it is sought to fatten an animal rapidly, every effort must be made to restrain muscular motion so far as compatible with health. Hence, the peculiar advantage of stall-feeding, in which the animal is confined to one spot, and the more thoroughly it can be kept still, the greater will be the economy of food. This is gained by darkening the house, and excluding all persons, except when their presence is indispensable. An extension of the same principle has led to the use of food artificially heated, but it is doubtful whether the advantages derived from it are commensurate to the increased expense of the process; at least opinions differ among the best informed practical men on this subject. Many other matters, besides these mentioned, exercise an important influence on the feeding of stock, such as the general health of the animal, the breed, etc. These are subjects, however, which bear more directly on practical agriculture, and need not be discussed here. The judicious feeder will not only give due weight to the principles already discussed in all he does, but he must take into consideration the extent to which they are liable to be modified in particular cases. He must also attend to the cost of different kinds of food, and the value of the manure produced by them, subjects of much importance in a practical point of view, and which must influence him greatly in choice of the particular substances he supplies to his cattle. INDEX. Acid, apocrenic, 21. Carbonic, 10, 15, 20, 37, 57, 115. Cerotic, 48. Crenic, 21. Geic, 21. Hippuric, 168. Humic, 21. Lactic, 168. Margaric, 47. Nitric, 11, 17, 30, 33, 38, 62, 112. Oleic, 47. Pectic, 46. Phosphoric, 73, 90. Stearic, 47. Sulphuric, 182, 237. Ulmic, 21. Uric, 168. Adulteration of guano, 211. Agricultural Chemistry Association of Scotland, 6. Air, influence of, on germination, 55. In the pores of soils, 115. Albite, 86. Albumen, 48. Albuminous constituents of plants and animals, 48. Algoa Bay guano, 208. Alkaline salts, value of, 260. Alumina, 73, 86, 103.