MifceUanea Cur to fa. 319 



Now thefe Materials being admitted, it 

 remains to be confidered, how they may be 

 kindled in order to fuch Explofion. As to 

 which,I have been told from Chymifts (though 

 I have not feen it tried) That a Mixture of 

 Sulphur, Fil.ings of Steel, with the Admitfion 

 of a little Water, will not only caufe a great 

 EfFervefcence, but will of it felf break forth 

 into an a&ual Fire. 



So that there wants only lome Chalybeat 

 or Vitriolick Vapour (or fomewhat equivalent) 

 to produce the whole Effect (there being no 

 want of Aqueous Matter in the Clouds.) 



And there is no doubt, but that amongfl 

 the various Effluvia from the Earth, there 

 may be copious Supplies of Matter for fuch 

 Mixtions. 



And 'tis known, that Hay, if laid up too 

 Green, will not only heat, but take Fire of 

 it felf. 



And while we are difcourling of this, it may 

 fuggeft fomewhat as to the Generation of Hail 

 which is very oft an attendant of Thunder 

 and Lightning. ? Tis well known, in our ar- 

 tificial Congelations, that a Mixture of Snow 

 and Nitre (or even common Salt) will caufe 

 a prefent and very fuddain Congelation of 

 Water. And the fame in Clouds may caufe 

 that of Hail-ftones. And the rather, beeaufe 

 (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, as to thofe in Particular (of which we 

 are now fpeaking) fo very large (as to weigh 

 Half a Pound, or Three Quarters of a Pound) 



flip- 



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