THE IRRIGATION AGE. 



333 



HON. FRED KIESEL, CHAIRMAN EX. COMMITTEE 

 llth NATIONAL IRRIGATION CONGRESS, OGDEN, UTAH. 



tact. Hydrogen, in its simple state, forms no part 

 of the food of plants because it does not exist in the 

 atmosphere or in the soil in any appreciable quan- 

 tities. Oxygen exists in the atmosphere in the gaseous 

 state and may be inhaled by the leaves of plants. 

 Nitrogen may be absorbed by the leaves of living plants, 

 but in a . quantity so small as to escape detection. 

 Horeover, oxygen and nitrogen being soluble in water 

 to a slight degree, may also be absorbed in small quan- 

 tities along with the water taken in through the pores 

 of the roots. 



But this absorption by the plant is insufficient to 

 maintain its life and growth. It must have a liberal 

 supply of food in which the four elements specified 

 form a large percentage. Now, this food can only 

 be obtained, or manufactured, by the four organic ele- 

 ments entering into mutual combinations to .form what 

 are known as "chemical compounds." It is these chem- 

 ical compounds which find their way into the interior 



of the plant, into its very substance, and then the 

 plant grows and reaches maturity, provided these chem- 

 ical combinations are continued during its period of 

 existence. 



It must be borne in mind that the atmosphere 

 diffuses itself everywhere. It makes its way into every 

 pore of the soil, carrying with it its oxygen, carbonic 

 acid and other substances it may be charged with, to 

 the dead vegetable matter and to every living root. Its 

 action is double: Playing among the leaves and 

 branches, and fondling the roots by mingling with the 

 soil. It is the workman, and its tools are its gases, 

 and with them it manufactures out of the raw material 

 it finds in the soil that is, the silica, the- sulphur, and 

 other inorganic substances, and the decayed organic 

 matter chemical combinations which the plant seizes, 

 appropriates and digests. 



CHEMICAL. COMBINATIONS. 



When common table salt and water are mixed the 

 salt dissolves and disappears. By evaporating the wa- 

 ter it is possible to' recover the salt in the same form 

 and condition as it was at first. This is called a 

 "mechanical combination," with which chemistry has 

 nothing to do, and which would not, in the economy 

 of nature, be sufficient aS a plant food, although such 

 combinations and solutions are absorbed by the plant 

 they do not feed it! 



But when limestone is put into a kiln and burned 

 it is changed into an entirely different substance, which 

 is called "quicklime." The limestone is decomposed by 

 the burning, "the carbonic acid mixed with lime is 

 driven off by the heat, and lime remains. 



So when svilphur is burned in the air it is all 

 converted into a white vapor of an unpleasant odor, 

 which is finally absorbed by the "atmosphere and dis- 

 appears. This is also a chemical decomposition, in 

 which the sulphur is combined with the oxygen of 

 the atmosphere. 



To cite another illustration, it may be said that 

 water itself is a chemical compound of the two ele- 

 mentary bodies, oxygen and hydrogen. 



None of these latter are mixtures like the mix- 

 ture of salt and water, but elementary bodies united 

 to form new substances, which, as has been said, are 

 called "chemical compounds," and it is through these 

 chemical combinations that all plants and fruits pos- 

 sess their various peculiarities. 



The number of compounds which the four organic 

 elements form with each other is practically unlim- 

 ited, but of them, a very few only minister to the 

 grow-th and nourishment of plants. Of these water, 



ADD1SON J. McCUNE, 

 ^ STATE ENGINEER, DENVER. COL. 



MR. FRANK BOND, WASHINGTON, D. C. 



