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Others pofitively deny this conclufion. Pure water, 

 it is true, is no menftruum for lead, but rarely do 

 we meet with water that is pure. Pump or fpring 

 water is generally impregnated with a fmall portion 

 of vitriolick or^ marine fait, but lead is hardly ca- 

 pable of detaching thefe acids from an%alkaline or 

 earthy bafis, and therefore cannot communicate any 

 poifonous quality to the water: hence this metal, 

 though immerfed in a folution of alum, remains 

 unchanged. Nor can the aerial acid enable water 

 to ad upon lead. But fhould the water contain any 

 mineral or vegetable acid, iincombincd with earth, 

 a circumftance which rarely occurs, it may then, 

 though in a very dilute ftate, corrode the metal 

 fufficiently to produce mifchievous effeds. This 

 feems aftually to have been the cafe at Worcefter. 

 For it certainly muft have been an acid, not alum, 



that corroded the lead. This may fuggefl to us 



the following cautions: 



I ft. That whenever water betrays any fenfible 

 mark of acidity, by an aluminous tafle, or by 

 changing fyrup of violets red, fuch water, if meant 

 for internal ufe, ought never' to come in contact 

 with lead. 



adly. Water conveyed from the leaden gutters of 

 houfes, or ftanding long in leaden citterns expofed 



to 



