CALORIC A UNIVERSAL SOLVENT. 227 



port; while solution or fluidity is essential to 

 every vital process.* 



* A complete history of the Mississippi river, would afford an 

 instructive example of the power of water in slowly dissolving 

 rocks, and transporting them to distant regions. Receiving as it 

 does, many large tributaries, that are fed by a thousand smaller 

 streams, which drain more than a million square miles of territory, 

 they pass through every variety of rocky strata. Some of its largest 

 tributaries, such as the Ohio, Missouri, Kentucky, Cumberland, 

 and Tennessee rivers, meander through extensive regions, based 

 on secondary limestone, which extends with occasional interrup- 

 tions, from Alabama to the falls of Niagara ; and varying from 

 500 to 2000 feet in depth. Through these immense beds of an- 

 cient limestone, they have furrowed channels from 200 to 400 

 feet deep. By their chemical solvent power, hundreds of sub- 

 terranean caverns have been gradually formed in the long lapse 

 of ages, with all those beautiful calcareous crystals termed sta- 

 lactites, with which many of them are so gorgeously decorated. 

 All valleys and river beds are slowly formed by the chemical and 

 mechanical agency of running water. Many springs also contain 

 in solution large quantities of carbonate of iron, which, as well 

 as lime, make a cement that binds into solid masses the beds 

 of loose sand through which they pass, forming sand stone. 

 Were we to follow out this subject in a geological point of view, 

 we should find that a great portion of the solid materials that 

 have been thus removed from the numerous valleys drained by 

 the Mississippi, have been transported to the gulf of Mexico, 

 which it is slowly filling up ; while the rest is conveyed by the 

 gulf stream into the wide Atlantic to form new rocks, after 

 having travelled thousands of miles in a state of invisible solu- 

 tion. The amount of soil, gravel, and sand, which are washed 

 down from mountains, hills, and plains, into the valleys during 

 floods of rain is enormous. The greater part of Louisiana, which 

 contains about 48,000 square miles, is composed of vegetable 

 mould, pebbles, gravel, sand, and clay, that have been conveyed 

 by this great river into the gulf of Mexico. Immense masses of 

 floating trees are also deposited on its banks and islands, and at 

 its mouth, which are covered by sand and clay, where they will 

 be gradually converted into beds of coal. Thus it is that every 

 thing in nature is in a state of perpetual transition and revolution. 



