Lti91 
ny fuch, was concreted of the breath of the Pyrites, which 
we have elfe where ftiewa to be the Pyrites ex tota Jub» 
ftantia. 
The other infta nee, which I fay is owing to our Regi- 
fters, is of Lightning being Magnetick. 
For this fee the Philofophical Tranladtions of Mr. Ol- 
denburg Number 127. 
This I am fure of, I have a petrified piece of Afli, which 
is Magnetick; that is, the Pyrites in j'^^^^ij ; which makes 
it probable it may be Magnetick alfo in vapour. 
M 
