PLANT LIFE ON THE FARM, 



CHAPTEE I. 

 PLANT-NUTRITION : THE WORK AND THE MATERIALS. 



Introductory remarks. What plants do and how they do it. Receipts. 

 Expenditure. Accumulation. Transformation. How plants 

 feed. Influence of temperature. Water and the machinery by 

 which it is supplied and distributed. Protoplasm. Cells and their 

 contents. Ingress and movements of water. The first stage of 

 nutrition. Diffusion. Osmosis and the requisite conditions for it. 

 Saturation. Varying degrees of, according to the nature of the 

 liquid. Amount absorbed. Supply and demand. Differences of 

 composition of plants grown in the same soil, how explained. 

 Continuous change. Nutritive value of water. Nitrates ; agency 

 of Bacteria. Potash. Sulphur. Phosphorus. Iron. Lime. 

 Principles of manuring. Power of selection. 



He who can make two blades of grass grow where only 

 one grew before is universally looked on as a benefactor 

 to his kind. No one will dispute his title to our grati- 

 tude ; but at the same time it must not be overlooked 

 that the claims of him who can make one grow where 

 none at all existed before, are even greater, because the 

 difficulties to be overcome are more formidable, for where 

 one exists already it is relatively easy to bring about its 

 increase. 



In any case, it is clear that, before either problem can 

 be satisfactorily solved, as full a knowledge as possible of 

 all the conditions requisite for the process must be in 



