336 ORGANIC CHEMISTRY. 



and every resin, is a distinct organic substance. In 

 the animal body, also, there is scarcely less variety. 

 The fluids which dissolve the food, the blood which 

 distributes it throughout the body, the color which tints 

 the skin aiid hair, and the milk "which nourishes the 

 young, are a few of the substances which it includes. 



852. MATERIALS OF VEGETABLE GROWTH. 



What arc the -..,' - . 



materials of With the exception of the small proportion 

 ^ mmera l matter which is derived from 



the earth, the materials out of which all 

 animal and vegetable matter is formed, are but few in 

 number. Carbonic acid, ammonia, and water, are all. 

 These are partly obtained from the air, and partly from 

 the earth. Carbon, hydrogen, oxygen, and nitrogen, 

 are the four elements which enter into their compo- 

 sition. 



What is re.- 853. CONVERSION OF THE MATERIALS. - 



workable in A vital force slumbers within the seed, 



the new pro- , . ,, 



parties which which in germination wakes to life. Call- 



result ? j ng to - tg a j^ fa Q ijgj lt an( j Warmt l 1 O f t h e 



sun, it weaves, as it were, out of the scanty mate- 

 rials which have been mentioned, all of the varied 

 forms of vegetable matter. Among the materials, one 

 is a tasteless solid ; the rest are tasteless gases. Yet 

 sweet, sour and bitter flavors result from their combi- 

 nation, with all the other boundless variety of the or- 

 ganic world. 



854. SIMILARITY OF COMPOSITION. Yet 



Give some in- , 



stances of aim- more remarkable than the limited number 



il ^olidth of elemeilts > fr m which so great a variety 



di/f rent pro- of organic substances is formed, is the 



per similarity of composition in many sub- 



