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fcended a great many times. I thought, at firft, it 
had fpun a new Thread at every Defeent, and was 
defirous to have meafured how long an one I could 
caufe it thus to fpin; but, upon a ftrider Examina- 
tion, I very plainly perceived, that whenever it 
afcended, it wound its Thread with its Feet into a 
fort of Coil, and when it defcended only ravelled k 
out again. 
The Manner how they perform this is diverting 
enough 5 but as Spiders may be had almoft in every 
Place, and the Experiment is fo eafily tried, I fnall 
forbear deferibing it; and only add, that as thefe 
Coils of Thread are exadly like thofe floating in 
the Air towards the End of Summer, I think it is 
not improbable thofe are made in the fame Manner* 
when Spiders have a Mind to dired their Courfe in 
the lame Direction their Threads lie. 
XVII. Some Remarks on the precious Stone 
called the Turquoife ; hy Cromwel Morti- 
mer, Sec. R. S. &c* 
Read Feb. Stone has received its modern 
,74 7 * A. Name of Turchejta y and Turquoife, 
from its being moft commonly brought from Turky 
into various Parts of Europe . * T)e Roodt * fays, the 
Colour of this Gem is a Variegation of Green, White, 
and Blue ; and that there are two Sorts of it, the 
oriental, from the Eaft Indies and Eerjta , and the 
occidental. 
•* Geramar, et Lap, Hift.- 
