CONTENTS. XI 



PAGE 



matter — Albumen — Fibrin— Caseine, milk, butter, and 

 cheese — Gelatine — Tanning, leather — Fat — Bone — Pro- 

 tein — Food of animals — ^Respiration — Circulation of 

 the blood — Digestion -^ Formation of fat — Cookery, 

 roasting and boiling — Action of medicines . . 199 



CHAPTER VII. 



The food of plants — Substances derived from the air — 

 Sources of oxygen, hydrogen, nitrogen, and carbon — 

 Substances derived from the soil — Sources of earthy 

 substances — Composition of soils, their formation — De- 

 composition of silicates — Mechanical structure of soils 

 — The saline constituents of soils — Organic matters in 

 soils, humus, humic acid ; their use in soils — Germina- 

 tion, malting — Moisture, air and warmth — Influence of 

 light — Office of the leaves — Roots — Formation of or- 

 ganic matter — Flowers, fruit, seeds — Organic and 

 organized matter — Vitality of embryo — Nature of 

 seeds — Earthy substances in plants — Effects of climate 

 — Action of plants on the air 246 



CHAPTER VIII. 



Deterioration of soils, its cause — Modes of maintaining 

 the fertility of the soil — Theory of fallowing — Rotation 

 of crops — Subsoil ploughing — Draining — Manure — 

 Organic manure — Animal manure, contains nitrogen 

 — Results of putrefaction — Sulphuretted hydrogen — 

 Loss of manure — Liquid manure — Animal excre- 

 ments, guano — Modes of fixing ammonia, by acids, by 

 gypsum, &c. — Strong manures — Wool, rags, oil — 

 Bones — ^Super-phosphate of lime — Vegetable manures 

 — Sawdust, seaweed — Green manures — Irrigation — 

 Inorganic manures — Lime, chalk, marl, shell sand — 



