C 503 ] 
hundred weight of the pureft copper, which fells 
at ten pounds per ton more than the copper, which is 
made of the ore. There are about 500 tons of iron 
now laid in thefe pits ; and the proprietors may, 
with proportionable advantage, lay in many thou- 
fands. ' 
The water, that runs from thefe mines, enters the 
river Arklow on New Bridge ; and is of fo corrofive 
a nature, that no filh can live in this large river from 
hence to the fea. 
If your lordlhip thinks thefe accounts worth notice, 
you may communicate them to fuch of your friends* 
and other curious perfons, as you pleafe. 
I am, with the hncereft refpedt, 
Your lordfhip’s molt obedient, 
and moil humble fervant, 
William Henry. 
LX XXV. Ex trail of a Letter to Dr. Maty, 
F. R. S. from Geneva, 'concerning the In- 
troduction and Succefs of Inoculation in 
that City. 
Read June i8,ttn September 1 750, the practice of in- 
l 7 S z - oculating the fmall-pox was firft in- 
troduced into Geneva. The example was fet by a 
young lady ; and was, the next year, follow’d in the 
hofpital of foundlings, where it was admitted by an 
order of the governors, and authorized by the magif- 
ftrates. 
