AGRICULTURAL TEXT-BOOK. 15 



will be better understood when we come to speak of the SOIL, 

 of DRAINING, and of MANURES. 



44. WATER consists of two volumes of hydrogen gas with one 

 roiiune of oxygen, chemically combined: or by weight: 



Oxygen, 88.91 8 



Hydrogen, - 11.09 1 



100.00 9 



The oxygen and hydrogen are therefore combined exactly in 

 the proportion 8 to 1, as appears by the proportion of the last 

 column. (Graham.) 



45. From the chemical combination of hydrogen ami oxygsn in water, 

 a scries of special consequences follows in the- organic kingdom. It is a 

 known fact that, when substances, chemically combined, are again de 

 composed, the action of other substances also, which are contained in tbe 

 circle of action is reciprocally awakened. Wherever in the organic 

 kingdom, water is decomposed and this frequently happens the de 

 composition re-acts on the substance from which the influence proceed 

 ed, and produces impoitant chemical transformations of all the substances 

 included in the circle of action. This chemical action proceeds, as 

 regards water, from two elements, which are both chief constituents of 

 organic bodies. (Mulder. ) 



46. (a.) The first effect of water on plants is that they are 

 moistened by it It acts chemically, forming hydrates with or 

 ganic compounds ; also, merely as a liquid, to moisten, dissolve, 

 or keep solid substances in suspension. 



47. (b.) Water is indispensable to keep the fleshy parts soft, 

 to enable them to grow and be fed. 



48. (c.) also as a dissolving and suspending fluid. 



For it is only by the circulation of a fluid through the existing 

 parts of an organic whole, that the support and nourishment of 

 the. whole organism can be effected ; and many of its actions 

 rest entirely upon this process. 



49. (d.) The action of water differs in plants and animals as 



