THIRD SUPPLEMENT 



TO THIS 



PHILADELPHIA 



MEDICAL AND PHYSICAL JOURNAL. 



I. Mineralogical and Chemical Account of the Yellow* 

 Springs, in the County of Chester, in Pennsylvania. 

 Communicated to the Editor, by a Gentleman norP 

 on a Mineralogical Tour through the United- States. 



Philadelphia, August 15th, 1808. 



SIR, 



1 HAVE the honour to enclose you a few Ob- 

 servations on the Qualities of the Yellow- Springs, in 

 the neighbourhood of this city. They are the result 

 of some experiments, made during a short excursion to 

 that agreeable place ; and, perhaps, have nothing to re- 

 commend them so much as a scrupulous attention to ac- 

 curacy. If they are thought deserving of a place in 

 your useful Journal y they are extremely at your service, 

 and I shall think whatever time I have bestowed on the 

 subject not altogether misapplied. 



I am, Sir, 

 Your very respectful humble servant, 



M. 

 Dr. B. S. Barton. 



