INDEX 



Absorption, by roots, 64 



Of salts, 72 

 Acid, acetic, transformation of, 280 



Formation of, 302-310 



Boracic, 77 



Carbonic, 3 



contained in the atmo- 

 sphere, 14 



decomposed by plants, 1 5 



disintegrates rocks, 113  



is furnished by humus, 29 



is expired by animals, 16 



is a product of decay, 299 



why necessary to plants, 64 



Cyanic, 84 



Formic, 41 

 Hippuric, 49 

 Humic, 5 



properties of, 5 



contains ammonia, 6 



Hydrocyanic, 266 



Kinic, 71 



Meconic, 71 



Melanic, 298 



Nitric, 214, 306 



Phosphoric, in ashes of plants, 



116 

 Rocellic, in plants, 65 

 Succinic, 343 

 Sulphuric, a source of sulphur, 



60 



retains ammonia, 181 



action on soils, 183 



Acids, action of, upon sugar, 278 

 Arrest decay, 296 

 Capacity of saturation, 6b 

 Organic, in plants, 3, 65 



how formed, 138 



— — — essential to formation of 



sugar, 137 



Agave Americana, absorbs oxy 



gen, 22 

 Agriculture, object of, 108 



How attained, 10S 



Its importance, 107 



A principle in, 179 



Science necessary to, 124 

 Air, access of, favored, 29 



Ammonia in, 43 



Carbonic acid in, 14 



Effect of upon juices, 302 



— «— on soils, 82 



Improved by plants, 16 



Necessary to respiration, 167 



to plants, 96 



Nitric acid contained in, 218 

 Albumen, 58, 134 

 Alcohol, effect of heat on, 281 



Products of its oxidation, 299 



From sugar, 287 

 Alkalies, contained in soils, S3, 92, 

 111 



Essential to the formation of 

 sugar, starch, and gum, 187 



Necessity for restoring to soils, 

 113 



Promotes decay of wood, 341 



Quantity of in aluminous mine- 

 rals, 111 



Use of in plants, 121 

 Alkaline Bases, in plants, on what 

 their existence depends, 70 



Salts in plants, source* of, 114 



contained in fertile soils, 



114 



• — liberated from soils, by th* 

 action of air and of lime, 12S 

 Alloxan, 3?4 

 Alloxantin, 307 

 Alumina, in fertile soils, 110 



its influence on vegetation, 11 J 



