HYDROLOGY. 121 



It follows, from this, that for all the multifarious order of 

 uses to which man applies this indispensable element, from 

 the building up of his "heaven-labored form, erect, divine," 

 to the humblest of domestic uses, pure water is the great 

 and indispensable want; pure water is the best, under all 

 conditions, to bathe in, consequently the best to wash the 

 human integuments or skin in ; it is the best water to wash 

 his outer covering or clothes in ; and emphatically the best to 

 supply the perpetually wasting vital streams within, or blood 

 currents of his body. 



The question of temperature or thermalism is one of in- 

 terest and importance. As a general thing, the springs of 

 the mountain have the general mean of their localities. 

 Some of the waters which are highly mineralized, and which 

 flow from the coal-bearing rocks, have a slight elevation of 

 their temperature. This is, no doubt, attributable to the 

 chemical changes of decomposition which occur within the 

 masses, from which the water derives its mineral contents. 

 Of this order is the well-known heat arising from the decom- 

 position of pyrites, which has been known to ignite coal and 

 other substances in contact with it. Of the class of warm 

 and hot springs, or those having a temperature over one 

 hundred degrees, there are no representatives in the moun- 

 tain, as yet discovered in Pennsylvania. 



Farther southwest the Appalachian range of fractures 

 and axes give some true thermal waters. See Moorman's 

 book on Springs of Virginia, and Geological Reports. 



Of the individual springs of medicated waters of Penn- 

 sylvania, a short notice will be in place. Some of these 

 waters have been the subject of extravagant encomiums, and 

 fictitious chemical analysis, purporting to possess fabulous and 



the Ottawa and St. Lawrence rivers, gives the presence of chloride 

 of sodium and potassium, sulphate, carbonate, and bromate of soda, 

 carbonate of lime and magnesia, silica, and a trace of alumina. The 

 analysis of Schuylkill water, by Booth, Garrett, and Camac, gives 

 the presence of silex, lime, soda, potash, magnesia, alumina, or oxide 

 of iron, the acids being sulphuric and carbonic. 



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