THE GROWTH AND NUTRITION OF PLANTS. 113 



MEETING FOR DISCUSSION. 

 The Growth and Nutrition of Plants. 



By Professor G. H. Whitcher, Director of the New Hampshire Agricultural Experi- 

 ment Station, Hanover, N. H. 



Mr. President^ Ladies and Gentlemen : 



The following general heads will indicate the line of my talk 

 today : 



1st. The Chemical Composition of Plants. 



2nd. "Whence the elements, from which these parts are made 

 Dp, are derived. 



3rd. Are all of these parts of equal importance? 



4th. Definition of terms, fertilizer, plant food, etc. 



oth. How do we feed plants and where get the material ? 



6th. How shall we decide upon the right food and the best 

 combination, under any given conditions? 



7th. Farm-yard manure compared with chemicals. 



8th. Chemicals compared with prepared or commercial fertili- 

 zers. 



Each of these heads would easily occupy an hour, but by con- 

 densation, I hope to touch upon all of them in one hour. 



(1.) Chemical Composition of Plants. — Chemical analysis 

 shows us that all growing plants, or air dried fodders, contain a 

 variety of substances having unlike properties. Thus, water, starch, 

 sugar, oil, fibre, albuminoids, and ash are found. Now if we are 

 to form an acquaintance with plants, we ought clearly to see and 

 know these facts. 



A green plant is cut, taken to the laboratory, and a fair sample 

 of the whole is weighed, and then dried in an oven at 212° until 

 it ceases to lose weight. The loss is loater. 



A field of standing grass is cut on a bright day, and in twelve 

 hours it has lost from one-half to two-thirds of its weight, and 

 this loss is icater. 



A potato is grated in water and the fine parts sink to the 

 bottom. By washing and settling several times, almost pure 

 starch is obtained. 



The seeds of the cotton plant, if subjected to pressure, yield a 

 considerable amount of oil. 

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