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SECT. IV. 



Method of analyzing Medicinal 

 Waters (t). 



Qui autem ad obfervandum adjicit animum, ei etiam, 

 in rebus quae vulgares yjdentur, multa obfervatu 

 digna occurrunt. 



Bacon de Augment. Scient. 



AS many fprings contain a volatile principle, 

 foon liable to be difllpated, it is neceilary 

 to make our experiments pn the fpot, in order 

 to difcover the contents of fuch waters. Various 

 as thefe contents may at firft appear, the appa- 

 ratus proper to detect all of them may be reduced 

 into a very fmall compafs. 



When we purpofe to examine any medicinal 

 fpring, the foil and face of the country mould 

 be confidered, the {tony or mineral appearance, 

 and particularly whether there are any mineral 

 veins the degree of heat of the water fliould be 

 afcertained by a thermometer, and its compara- 

 tive weight to other fprings in the neighbour- 

 hood alio carefully obferved ; after which we 

 may enter on our experiments. 



(t) Wallerius in his Hydrologia, Lewis in his notes on 

 Neumann's chemiftry, with Rutty, Lucas, Falconer, Monro, 

 and other writers, have given directions upon this fubject ; 

 but my friend Dr. Walker of Hull has treated it profeffedly 

 in his elegant Thefis de Aqua Sulphurea Harrowgatenfi, 

 Edinb. 1770, dedicated to that learned Chemiit andPhilofo- 

 pher Dr. Black. 



I. AERIAL 



