( ^57 ) 
of any Body fo liabk to a fuddain and violent Ex- 
plofion. 
Now thefe Materials being admitted, it renaains to 
be confidered, how they may be kindled in order to 
fuch Explofion. As to which, I have been told from 
Chymifts (chough I have not feen it tryed) That a 
Mixture of Sulphur , Filings of Steel, with the Ad- 
miflion of a little Water, will not only caufe a great 
EfFervefcence, but will of it felf break forth into an 
adlual Fire. 
So that there wants only fome Chalybeat or Vi- 
triolick Vapour (or fomewhat equivalent) to produce 
the whole EfTed (there being no want of Aqueous Mat- 
ter in the Clouds.) 
And there is no doubt, but that amongft the various 
Effluvia from the Earth, there may be copious Sup- 
plies of Matter for fuch Mixtions. 
. And "^cis known, that Hay, if laid up too Green^ 
will not only heat, but take Fire of it felf. 
And while we are difcouf fing of this, it may (ug- 
geft fomewhat as to the Generation of Hail, which 
is very oft an attendant of Thunder and Lightning. 
'Tis well known, in our artificial Congelations, that a 
Mixture of Snow and Nitre ( or even common Salt ) 
will caufe a prefent and very (udden Congelation of 
Water. And the fame in Clouds may caufe that of 
Hail-ftones. And the rather, becaufe (not only in 
thofe prodigioufly great, but in common Hail'ftones) 
there feems fomewhat like Snow rather than Ice, in the 
midft of them. 
And. 
