CONTENTS. 



PAKT I. 



OP THE KNOWLEDGE REQUIRED BY A SUGGESTER AND MAKER OP 



EXPERIMENTS, AND OF THE WAY IN WHICH EXPERIMENTS 



OUGHT TO BE MADE AND CRITICISED. 



CHAPTER I. 



KNOWLEDGE NECESSARY IN A SUGGESTER AND MAKER OF EXPERIMENTS. 



Page 



1. Purposes for which experiments are made. Object of the suggestions 



contained in the present work, . . . 



2. Knowledge which ought to be possessed by the suggester and per- 



former of agricultural experiments, .... 6 



3. Substances of which the plant consists, .... 7 



4. Functions performed in plants by their organic and inorganic or 



mineral constituents, ...... 9 



5. Functions of the several parts of plants, . . . .11 



6. Habits and analogies of the species of plants on which experiments 



are to be made, and of their several varieties, . . . ' 14 



7. Of what the soil consists, ...... 17 



8. Differences of soils arising from their geological origin. Value of local 



geology and physical geography, . . . . .19 



9. The composition of local streams and springs, and of local rocks, . 20 



CHAPTER II. 



KNOWLEDGE NECESSARY TO A SUGGESTER OF EXPERIMENTS Continued. 



1. States of chemical combination in which substances exist in the soil 



and enter into plants, . . . . . .22 



2. The general composition of manures, natural and artificial, . 24 



3. General principles of husbandry. Knowledge of local and individual 



practice, . ...... 25 



