[ 35 ] 
Received February 20, 17 66. 
VII. ExtraB from Two Letters , dated De- 
cember 7 th and i 2 th y 1765, frojn the 
Rev . Mr. William Borlafe, of Ludgvan, 
in Cornwall, F. R . xS 1 . /a Emanuel Mendes 
da Cofta, Librarian , &c. to the Royal 
Dear Sir; 
Read *66** N board the Spackman tin {hip, I 
have fent a contribution to the 
foffil collection of the Royal Society, which I beg 
you will prefent with my duty and refpeCts to that 
illuftrious body; it is 
NATIVE TIN, 
a rarity indeed ! and I (hall not be eafy till I hear it 
is fafely lodged in your Mufeum, as it is the faireft 
Ipecimen I have feen. 
As the exigence of Native Tin is abfolutely de- 
nied by all mineralifts both antient and modern ; and 
at the time I wrote my Natural Hiftory of Cornwall, 
having no evidences before me to evince the con- 
trary, I contented myfelf with fuggefting, page 18 y, 
that its exiftence was far from being improbable, and 
in that manner I left the difpute undecided. But a 
late fortunate difcovery, which has furnilhed me with 
F 2 three 
