of $?agnettfm* 7 



This fhori Memorial being added 

 to the preceding part of this di£ 

 cou:ity*5H, I hope, (atisfie you, that 

 how unafiiindufly io ever men have 

 deduced all Qjagnetick operations 

 from the form of the Loadftone^ 

 yet fome internal change of pores 

 or fome other Mechanical alterati- 

 ons or inward difpofition, either of 

 the excited Iron or of the Load- 

 ftone it felf, may fuffice to make a 

 body capable or uncapable of exer- 

 cifing fome determinate magnetical 

 operations 5 which may invite you 

 to caft a more unprejudiced eye up- 

 on thofe few particular*, Uhallnow 

 fubjoin to make it probable^ that 

 even Magnetical Qualities may be 

 Mechanically produced or altered* 



EXPER. V. 



JHave often obferved in the 

 (hops of Artificers -, as Smiths, 

 urners of metals &c. that, when 

 hardened and well tempered tools 

 are well heated by Attrition , if 



whileft 



