46 SCIENTIFIC AGRICULTURE, 



GASEOUS COMPOUNDS. 



WATER ITS PROPERTIES AXD RELATIONS. 



Pure water is transparent, colorless, tasteless, and inodor- 

 ous: it is a compound of the gases oxygen and hydrogen, in 

 the proportion of 8 parts of the former to 1 of the latter, by 

 weight, or by volume, 1 of oxygen to 2 of hydrogen. It 

 boils, under ordinary circumstances, at 212 and freezes at 

 82o, Fall. : its greatest density is at about 40, at 212, it 

 takes the form of vapor or steam, and is thus increased to 

 1700 times its former bulk, and is about two-fifths lighter than 

 common air, it consequently rises and becomes diffused 

 through the air. 



Water evaporates at all temperatures above freezing: it is 

 780 times heavier than common air, a cubic foot weighs six- 

 ty-two and a half pounds. It is the standard of specific gravity 

 for all bodies, its number in this respect is unity or 1. 



The purest water, except that which has been distilled, falls 

 from the clouds in the form of rain and snow at the close of a 

 shower: all other natural waters contain various soluble and 

 insoluble gaseous, mineral and organic matters, among which 

 are, carbonic acid, carbonate of lime, ammonia, salts of iron, 

 soda, iodine, bromine, magnesia, silica, sulphur and others. 

 "Water possesses the most extensive solvent power of all known 

 liquids : it absorbs gases from the air to a considerable amount : 

 these are again expelled by boiling, and are altered in their 

 proportions from those which constitute the atmosphere. 



Water mixes with, or dissolves all liquids except those of an 

 oily nature : it dissolves also most salts, many gums, coloring 

 matters, and slowly dissolves many rocks and earths: water 

 has a wide range of affinities for animal, vegetable and mine- 

 ral elements, which it exercises without being itself decom- 

 posed, It is the most universally diffused through the three 



