C 284 ] 
But (till more curious than all the reft are certain 
Lumps of petrified cryftallized Matter, of a very odd 
Form, fuch as I have never feen or ever read of. 
They appear to have been originally Lumps of 
blue Clay, cracked by fome fubterraneous Heat, 
or other unknown Caufe, into which the Wa- 
ter has infinuated, and the Salts contained therein 
have cryftallized in the Cracks. 
When thefe Lumps are taken up, and become dry, 
the Clay Part falls from out the exterior Cells ; and 
then they may be thought grofly to reprefent an Ho- 
ney-Comb. At firft I took them to be Bones from 
within-fide the Skull of fome great Filh, or other 
Sea Animal ; but fome which I have feen lately, and 
of which I fhall fend you a Specimen, have con- 
vinced me I was miftaken. Indeed fince I wrote the 
above, I have compared this Foffil with the Defcrip- 
tion Dr. Woodward, gives of the Ludus Helmontii, 
and I think it agrees fomewhat therewith. 
V. 
