confined way content ones felf to deliver 

 fuch Experiments and Obfervations of 

 the Production , or the Deftru&ion or 

 Change of this or that Quality, as, being 

 duly reafon'd on , may fuflice to (hew 

 wherein the nature of that Quality doth 

 confift , efpecial!y in oppofition to thole 

 erroneous conceits that have been enter- 

 tained about it, Of the Firfi of thefe 

 three ways of treating of a Quality I 

 pretend not to have given any comfleat 

 example i but you will find, that I have 

 begun fuch Hittories in my Specimens a- 

 bout Fluidity and Firmnefs, and in the 

 Experiments, Obfervations, &c. that I 

 have put together about Cold* The Second 

 fort of Historical Writings I have given an 

 Inftance of in my Experiments about Co- 

 lours h but in th^fe enfuing Notes, the 

 occafion I had to make them having ob- 

 liged me chiefly to have an eye to the dif- 

 proval of the errours of the Peripateticks 

 ind the Chymifts about them, I hope I 

 fhall not be thought to have fallen very 

 ihort in my Attempt, if I have ( here 

 and there ) perform 'd what may be re- 

 quired in the Third way of writing Hifto- 

 rically of a Quality i my prefent Defign 

 being chiefly to give an Intelligent arid 

 Hiftorical Account of th? Poffible Me- 

 chanical Origination, not of the various 



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