[ 447 ] 
in the various operations of nature. It is in confe- 
qdence of fuch a motion, arifing from a certain degree 
of heat, that the Tourmalin, and the other gems, are 
rendered ftrongly eleCtric : and this plainly fhews, that 
a lefs degree, even that which accompanies them 
where they are found, may make them alfo eleCtric $ 
but with the difference of making them lefs fenfibly 
fo. Accordingly, having explained what he means 
by the word attraction , he fays, “ The attraction of 
“ gravity, magnetifm, and eleCtricity, reach to very 
“ fenfible diftances, and fo have been obferved by 
“ vulgar eyes ; and there may be others which reach 
“ to fo fmall diftances as hitherto efcape obfervation, 
“ and perhaps eleCtrical attraction may reach to fuch 
<c fmall diftances, even without being excited by fric - 
‘ c tion.” 
London, 
December 23, 1764. 
LX VIII. 0bfervatio7is on the Slides in the 
Straits of Gibraltar ; by Henry More, 
Efr, 
v 
Read Jan. 28, A S every attempt made, whether at- 
f tended with fuccefs or not, to- 
wards illuftrating what is already known, or drawing 
from obfcurity for want of fufhcient obfervation, or 
fcouring off the rufl of, error from reality, either 
through curiofity or order, has always met with the 
candid countenance of your mod honourable Society ; 
Vol. LII. Mmm I heg 
