SOLVENT POWER OF WATER. 47 



of oxygen, against 21 per cent, in the ordinary atmosphere; 

 the difference being absorbed by the snow, is carried into 

 the soil with the water as the snow melts and thus conveys 

 to the roots an additional supply of this vitalizing element. 



In its fluid condition, water is the vehicle by which all 

 nutriment of whatever kind, is carried into the circulation of 

 plante. It is itself a most important nutritive element 

 food in fact for all plants and animals, forming about 

 three-fourths of their substance and weight. It thus softens 

 all tissue and gives it elasticity and strength. It is a uni- 

 versal solvent; and thus brings to the roots of plants \ what- 

 ever nutriment is needed in such a form that it can be taken 

 into their tissues. It dissolves about one-thirty-sixth part of 

 its volume of air ; and this air contains 10 percent, more 

 oxygen than other air. It also contains from two to twelve 

 times as much carbonic acid as the ordinary air. One 

 hundred volumes of water absorb directly 3.55 of oxygen ; 

 1.53 of hydrogen; 1.47 of nitrogen; 106 of carbonic, acid, 

 or 7800 of ammonia. In this property we see how plants 

 may derive the large supply of carbonic acid which they 

 need for the structure of their carbonaceous tissue ; and a 

 large proportion of their nitrogen which may thus be pro- 

 cured from the dissolved ammonia. 



Water is never pure. As an example of its solvent power 

 over solid mineral substances the following analysis of the 

 water of the Dead Sea is given. 



Specific gravity of the water 1.172 



Chloride of sodium (salt) 0702.73 grains. 



Chloride of potassium 682.63 " 



Chloride of ammonium 3.35 " 



Chloride of lime 1376.75 " 



Chloride of magnesia 4457.23 " 



Chloride of aluminium 31.37 " 



Chloride of iron 1.50 " 



Chloride of manganese 3.35 



Bromide of soda 156.53 



Iodide of soda trace 



Sulphate of potassium trace 



Sulphate of Magnesia trace 



Sulphate of lime 38.07 



Phosphate of soda trace 



Carbonate of lime.... 



