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MEDICAL PAPERS 



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the relief of the fick, or the reinftatement of an impaired 

 conftitution. 



From thefe confiderations, I have undertaken to try the 

 following experiments upon the Chalybeate waters of 

 Brifto], in Pennfylvania, with a view to difcover their 

 contents, as a guide to the further inveftigation of their 

 virtues and ufes; and particularly, their application in the 

 cure of difeafes. For although it muft be confefTed, that 

 a chymical analyfis is, in fome meafure, an uncertain teft 

 of the medical virtues of any compound; and that the 

 qualities of its conflituent parts, when feparated, may not 

 only differ from, but are fometimes oppofite to, thofe of 

 the mixture ; yet when we want the teftimony of experi- 

 ence, a chymical analyfis is the heft means of inveftigatiu) 

 the truth, and difcovering the virtues of the compound. ' 



Thus, if from the following experiments it fhall be 

 found that t!ie waters of Briftol, are impregnated with the 

 principles of thofe of Bath or Spa, it will be no forced 

 conclufion to iay, they may be bcneiicial in cafes fimilar 

 to thefe that have been happily cured by the kitten 



Experiment L A fmall portion of white oak bark, in- 

 fufed in the waters, induced an immediate change from 

 tranfparency to a dark purple colour, which it retained 24 

 hours, without de})()fiting any fediment, 



II. Some of the fame water, after being made hot, or 

 expofed for a few hours to the open air, in a great mea- 

 fure loft its irony taRe, and received no other colour than a 

 common tindure from the white oak bark. 



III. One drop of flrong oil of vitriol, in two ounces of 

 the water, produced no lenfible alteration ; and the water 

 after ftanding fome time continued tranfparent, without 

 depofiting any okerifli or other fediment to the fides or 

 bottom. 



' IV. OL tart. pr. deliq. dropt in fome of the fame water, 

 induced a change in the colour, rendering it fomewhat 

 yellow; and in time precipitated to the bottom of the cup 



a fine gold coloured oker. 



V. Sixteen 



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