( 39 ) 



communicate ; fo that it is indeed a wonder, that 

 we find this water at ail tolerable *. 



THAMES and NEW- RIVER 

 WATER, 



River waters partake of the properties of their 

 fprings, and the channels, through which they 

 run ; yet, in a wonderful manner, they foon free 

 themfelves from their impurities. The motion of 

 the current f, the abforption of the foil, the fun 

 and rain, have each of them a confiderable fharc 

 in this efFed. 



. The Thames water, efpecially In the neigh- 

 botirhood of London, is mixed with many impure 

 ingredients. It is faid to become ofFenfive in fe- 

 ven or eight days, or fometimes fooner, if it be 

 kept in unfeafoned cafks. In this flate it gene- 

 rates a quantity of foul inflammable air, as may 

 be feen by holding the flame of a candle to the 

 bung-hole of a calk when it is firfl opened; But 



by 



♦ See Medical Tranfad. vol. i. 



f The moft rapid rivers contain, caeteris paribus, the 

 pureil water. 



