HOW PLANTS GROV/. 



a:N address before the state POMOLOGICAL society at IONIA, 

 DECEMBER 2, 1874, BY PROF. W. J. BEAL, AGRICULTURAL 



COLLEGE, LANSING. 



SOURCE OF FOOD, — ELEMENTS XECESSARY. 



All substances, so far as known, are made of a little over sixty simple ele- 

 ments. 



Chemists have proven that fourteen of these elements (bodies which have 

 never been decomposed) are essential to the growth and maturity of every 

 common flowering plant, and of animals too, since they feed upon plants. 



One of the most common and characteristic elements of plants is 



Carbon, (C.) which exists nearly in a pure state as charcoal, lamp-black, 

 black lead, and the diamond. It constitutes about 46 per cent of plants. 



Oxygen, (0.) is a colorless, odorless, tasteless gas, constituting a large part 

 of the air we breathe. It combines with most other elements with great read- 

 iness. It constitutes more than one-half of the aggregate materials of the 

 globe, about 40 per cent of plants. 



Hydrogen, (H.) is a gas without color, odor, or taste. It is the lightest sub- 

 stance known. It unites with oxygen to form water. United with carbon it 

 forms the chief ingredients of many compounds, as volatile oils, coal gas, ben- 

 zines, tallow, etc. About five and a half parts out of 100 in plants by weight 

 are compounds of hydrogen. 



Nitrogc?i, (N.) is abundant in the air, as an inert gas, without color, taste, 

 or smell. It constitutes about two per cent of plants, existing in a greater 

 proportion in the seeds, and young stems and leaves which are edible. 



Sulphur, (S.) is well known as a yellow substance in the form of brimstone. 

 It exists in small quantities in all plants, perhaps 15 parts in 10,000. 



F?iosphorus, (P.) is never found free in nature. It consists of about four 

 parts in 100 of plants. It constitutes the chief value of bones as a manure. 



The above are the six most important elements of plants. 



Silicon is never found naturally in the free state. Combined with oxygen 

 it forms silica, an exceedingly abundant substance in sand and in most soils. 

 The other elements necessary to plants are chlorine, potassium, sodium, cal- 

 cium, magnesium, iron, manganese. Still others are sometimes found. 



The above fourteen elements are chiefly obtained from oxygen of the air, 

 21 



