[ 6 4 B ] 
N. B. Number 57 and 84, are anomalous figures 
of fnow; of which there is an infinite variety, that 
may be obferved. 
XCIX. An Account .of the Copper-fprings 
lately dif covered in Pennfylvania : By ]o\m 
Rutty, M. D . of Dublin. Communicated 
by Mr. Peter Collinfon, F. R. S. 
Read May 20 , "W jq the province of Pennfylvania is acop- 
per-mine, which affords a fpring, that 
appears to have the fame qualities as that Jrifh water, 
lately deferibed by Dr. William Henry and Dr. Bond 
in the 47th and 48th volumes of the Philofopbical 
Franfattions, but is much fharper, for it will diffolve 
iron in a quarter part of the time ; and we are a ffu red, 
by the accounts tranfmitted from the proprietors of it 
of the trials they have made, that it yields the fame 
copper-mud or duft as our Cronebaun-water, of the 
county of Wicklow, in this kingdom (being the water 
above mentioned) which being collected from bars of 
iron immerfed in it, for the purpofe of extrading the 
copper from the Pennfylvania water, it produced above 
half pure copper on being melted in a crucible ; an 
experiment, that requires to be repeated, in order ta 
afeertain the proportion of copper contained with ac- 
curacy ; our copper-fpring of the county of Wick- 
low yielding a proportion confiderably larger than 
this, viz. 16 parts of copper out of 20 of the mud. 
In the neighbourhood is a great abundance of the. 
ores of vitriol and fulphur, and the fpring comes 
thro’- 
