TABLE OF CONTENTS. 



INTRODUCTION. 



Page. 

 Agriculture defined — its importance 17 



Aid which it may derive from the Natural sciences . . .18 



I. Mineralogy and Geology 18 



II. Chemistry 19 



III. Botany 24 



Plan of the Work ■ 25 



Influence of slight improvements 26 



BIOLOGY OF PLANTS. 



CHAPTER I.— The Vital Principle, 

 Division of Natural bodies 29 



Sect. 1. Definitions and descriptions — proofs^ nature and uses of the 

 Vital Principle. 



Definition of Biology 29 



Of an organized body 30 



Definition of a plant 30 



Tissue defined and described 30 



Cells 30 



Spiral vessels — Pores — Cuticle — Wood . • . . . 31 

 Cambium, Alburnum, Assimilation, Transpiration . . .38 



Comparison of the Vital Principle in animals and plants . . 33 

 Proofs of the existence of Vitality. 



I. Power of vegetables to resist natural laws — 1. Chemical affini- 

 ty. 2. Gravity. 3. Heat and Cold 35 



II. Excitability in vegetables. — 1. Influence of light. 2. Of heat 36 

 3. Of electricity. 4. Of artificial stimulants . . . .37 



III. Irritability of vegetables ....... 37 



IV. Productions of the vegetable kingdom . . . .37 



JVature of Vitality — Biological hypotheses 38 



Definition of life 39 



