£ 820 ] 
An ingenious Ketrzdiztion of the 7th andla/iParz^ 
graph of Mr. William }Aolyneuyi's Letter in the 
Philofophical Tranfaft. Numb. 158. pag- 554. 
concerning Lough Neagh Stone and its non ap- 
plication to the Magnet upon calcination. Be- 
ing an ahJlraSl of a Letter of the fame ingeni- 
0/^ Gentleman dated fromYivkXm Novemb. 25. 
1684.. 
nr^IS now a good while fince J gave you fome 
account of our Lough-Neagh Stone and its 
petrifying qualities, which 1 hear you have thought 
worthy to inlert in one of your Tranfa^ions ; in 
which difcourfe I muft defire you to correft one 
Paragraph^ and undeceive the World in a parti- 
cular there mention'd ; which is, that Lough-Neagh 
Stone^ neither crude nor calcined., would appiy^ 
to the Magnet \ that it will not do fo crude ^ I ft ill » 
affirm; but that it does not zpply calcind^ I muft 
retraft : for Ifind by further trial, that it apply's 
calcin'd moft briskly , and in great quantities^ to 
the Magnet : The occafion of my former error be- 
ing, that I did not calcine \t long enough. If upon 
a fit opportunity you would dome jufticeinthis 
particular ^ you will much oblige me, and vindi- 
cat my credit. Sir, lam 
Your moft humble Servant^ 
Willi a /n Molyneuxi 
