[ 35 ^ ] 
have been dcfcribing, quite finifhed. I could urge 
many Reafons for my Suppofition, but I will not 
trouble you with them here, the Compafs of this 
Letter not permitting me ; nor do I know how far 
fuch Conjedlures are capable of being ufed, with 
regard to the received Opinion of the World’s Age; 
but if wc had as good Authority to fuppofe it 60,000 
Years old, as we have 6000, it would be worth the 
while to trace the Origin and Source of thefe petri- 
fying Exhalations a little deeper than feems to have 
been done by Dr, Woodward ; and might either per- 
fed his Hiftory, or produce a more rational Syftem 
of the Earth than has yet appeared. 
You will find, amongft the things I fend, fome 
Land-coral found in a Lime-pit, where is a great 
Quantity of it, between Two Strata of Lime-ftone 
of at leaft Three Foot thick. You will find alfo 
fome few Pieces of ^feudo-fapphirus^ and other 
kinds of Spar ; they are fuch as I picked out of the 
Fiflures of the Rocks I have been dcfcribing. There 
is a vaft Variety of thefe things in the Veakt much 
greater than hath been taken Notice of by any one ; 
as 1 fliall convince the Royal Society, when I 
am able to prefent them with a complete Colledion 
of ‘Derhyjhire Foflils, in which I have already made 
fome Progrefs : Who am, 
SIRy 
Burton, Nov. 26 . 1735 . Servant, 
Moreton Gilks. 
XVIII. Tart 
