(375) 
which are perfe&ly well wrought and well polifht. Thofe, that 
have tried them , find them very good , but they are only, the one 
of io, the other of 8. foot. A good Aftronomer told me, that 
they would bear a great Aperture in refped of their length. 
I do not well know, what to fay to yours concerning M» Beve* 
lius., Meanwhile, the intereft of truth , and the obliging manner, 
lie has treated me with , engage me to anfwer him , in the matter 
of the Comets : I am perfwaded, I fhaji convince him $ but fince he 
hath taken the / Uu firms Royal Society for Judge , I accept that 
with all my heart. 
of the lofs of the Way to prepare the Bononian Stone 
for pining . 
Though feveral Perfons have pretended to know the Art of i 
preparing and calcining the Bononian Stone , for keeping a while 
the Light once imbibed $ yet there hath been indeed but one, 
who had the true fecret of performing it. This was an Ecclefafltcf , 
who is now dead, without having left that skill of his to anyone, 
as Letters from Italy and France , fome while fince , did inform. 
There is no fubftance, in Nature, known to us, that hath the effed 
of this Stone | fo that (to the fhame of the prefent Age) this, , 
?h*r>emnm is not like to be fonnd t , ltlf ho H notBithft!nd;ns 
any where , but in Books, except (which alfo a late Letter from abroad 
- This was communicated to the ft. Society by Sir Gilbert Talbot 
i Knight , a Worthy Member of that Body , as he had received it 
in Denmark , being his, Majeflies Extraordinary Envoy there * as 
follows, 
! '®THere is a Stone in Sweden of a Yellow Colour , intermixed j 
with {freaks of white (as if compofed of Gold and Silver) 
and heavy withal. It is found in firm Rocks , and runs in Veins, 
A Relation 
A Depription 
of a Swedifii.Sftwe, which affords Sulphur, Vitriol, , 
Allum* and Minium. 
