CONTENTS. 



PAOB 



LETTER IX. 



Growth of Animals. Use of Butter and Milk. Metamorphoses of Tis- 

 sues. Food and Carnivora, and of the Horse - - - - -27 



LETTER X. 



Application of the preceding Facts to MAN. Division of human food. 

 Uses of Gelatine - - , y v - - 29 



LETTER XI. 



CIRCULATION OF MATTER IN THE ANIMAL AND VEGETABLE KINGDOMS. 

 The Ocean. AGRICULTURE. RESTITUTION or AN EQUILIBRIUM IN 

 THE SOIL. Causes of the exhaustion of Land. Virginia. England. 

 Relief gained by importation of bones. Empirical Farming unsatisfac- 

 tory. Necessity for scientific principles. Influence of the Atmosphere. 

 Of Saline and Earthy matters of the soil - - ".-**' - 31 



LETTER XII. 



SCIENCE AND ART OP AGRICULTURE. NECESSITY OF CHEMISTRY. Ra- 

 tionale of agricultural process. Washing for Gold. - 1_*. 34 



LETTER XIII. 



ILLUSTRATION OF THE NECESSITY OF CHEMISTRY TO ADVANCE AND PER- 

 FECT AGRICULTURE. Manner in which FALLOW ameliorates the soil. 

 Use of Lime. Effects of Burning. Of Marl '/- *H ; - 36 



LETTER XIV. 



NATURE AND EFFECTS OF MANURES. Animal bodies subject to constant 

 waste. Parts separating exuviae waste vegetable matters together 

 contain all the elements of the soil and of food. Various value of ex- 

 crements of different animals as manure - - - V t/* 5 * ^8 



LETTER XV. 



SOURCE OF THE CARBON AND NITROGEN OF PLANTS. Produce of Carbon 

 in Forests and Meadows supplied only with mineral aliments prove it 

 to be from the atmosphere. Relations between Mineral constituents, 

 and Carbon and Nitrogen. Effects of the Carbonic Acid and Ammonia 

 of Manures. Necessity of inorganic constituents to the formation of 

 aliments, of blood, and therefore of nutrition. NECESSITY of IN- 

 QUIRIES by ANALYSIS to advance AGRICULTURE - - 41 



LETTER XVI. 



RESULTS OF THE AUTHOR'S LATEST INQUIRIES. Superlative importance 

 of the PHOSPHATES OF LIME and ALKALIES to the cultivation of the 

 CERALIA. SOURCES of a SUPPLY of these MATERIALS - - - 46 



