CONTENTS. 



Preface to the Third American Edition 



Dedication 



Preface to the Second English Edition 



Object of the Work 



PAGB 



V 

 XIII 

 XVII 



21 



PART FIRST. 



ON THE CHEMICAL PROCESSES IN THE NUTRITION OF VEGETABLES. 



dHAPTBR PAGB 



I. — On the Constituent Elements of Plants . . 24 



n. — On the Assimilation of Carbon . . ,30 



ni. — On the Origin and Action of Humus . . 63 



IV. — On the Assimilation of Hydrogen . . .80 



V. — On the Origin and Assimilation of Nitrogen . 85 



VI. — On the Inorganic Constituents of Plants • . 105 



Vn. — The Art of Culture .... 126 



Vni. — On the Alternation (Rotation) of Crops . .161 



IX. — On Manure ..... 174 



Supplementary Chapter. —On the Chemical Constitu- 

 ents of Soils . . , . . 208 

 Appendix to P^rt I. ..... 249 



Action of Charcoal on Vegetation , . 249 



Mode of Manuring Vines .... 253 



Root Secretions ..... 256 



Peat Compost ..... 258 



Source of the Carbon of Plants . . . 260 



Source of the Hydrogen of Plants . . . 263 



Dependence of the Nutritive Qualities of Plants on 



Nitrogen . . . . .265 



