CONTENTS. 



CHAPTER I. 



THE TLANT. 



Chemical aud cosmic couditious of the life of plants — Conditious for the 

 germination of the seed ; moisture and oxygen, their action — Influence of 

 the seed in the formation of the organs of absorption, aud the production 

 of varieties ; influence of climate and soil in producing varieties — Im- 

 portance of a Imowledge of the developement of roots; radication of 

 different plants — Comparison of the process of vegetation in annual, 

 biennial and perennial plants — Growth of the asparagus, as an example 

 of a perennial plant ; storing of reserve food in its underground organs ; 

 use of this store — Meadow and woody plants — Growth of biennial 

 plants; tm-nips: Anderson's experiments — Growth of annual plants; 

 summer plants : tobacco ; winter wheat, its developement like biennial 

 plants ; oats : Arendt's experiments ; Knopp's experiments with maize in 

 flower — The protoplasteni (matter for forming cells); conditions for its 

 foiTuatiou ; Boussingaidt's experiments ; organic processes in plants, 

 directed to the formation of the protoplasteni — Absoi-]:)tiou of food by 

 plants not an osmotic process ; marine-plants ; duck-weed ; land-plants ; 

 Hale's experiments on absorption by the roots and evaporation from the 

 leaves — Power of the root to exclude certain substances from absorption 

 not absolute ; Forchhammer, Knopp — Comportment of the roots of land 

 and water plants to solutions of salts ; I)e Saussure, Schlossberger ; com- 

 portment of land-plants to solutions of salts in the soil — Use of those 

 mineral matters which are constant in difterent species of plants : iron, 

 magnesia, iodine, and chlorine compounds — Absoi-ption of matters by 

 plants from the surroimding medium ; influence of the consumption of them 

 by the plant ; part played by the roots in their absorption . pagk 1 



CHAPTER II. 



THE SOIL. 



The soil contains the food of plants — Soil and subsoil; conversion of the 

 latter into the former — Power of the soil to withdraw tlie food of 

 plants from solution in pure and in carbonic acid water ; similar action of 

 charcoal ; process of surface attraction ; chemical decomposition often 

 accompanies this attraction of the food of plants in the soil ; genenJ 

 resemblance of the soil in its action to animal charcoal — All arable soils 



