thoughts of Petnficatiom^ which fterhaps will not be un- 
acceptable to you^and therefore 1 (hall tranfcrib^ it from 
his Letter, dated Augufi i^x\ 169^. At Harwich, 
under the Cliffy upon the Sea flme^' there is a Stratum of a 
Clayie- Stone, Xi?hkh is cover d here dffd there with ragged 
Stones of a do fer texture^ which was former ly (^l conje&ure^ 
another entire Stratum, hut is broken tht^ bj the Tearing of 
the Waves. The Clayie-Stone Stratum , Mr Dale and 
Mr Lilffkin my Companions were of opinion had been former* 
ly a fofter fib fiance^ but was dail^ petrified ly the Sea IVatcr^ 
Having argued a little about' it^ rchen turning to the Cliffy I 
found a Stratum there^ of the very fame fort ^?/Clayie-StOne 
with^that upon the Shore '-^ yet the Sea waters-very feldom 
comes up hither^ unlefs by Storms and at Spring-tydes, I 
hroh^ a little piece off^ and fjew'dit to you^ ^and then you 
was convincd ( I* thinly) it was not hardned or petrified by 
the Sea water^ but in its natural fiate* And I have often\ 
1 ajfure you^ met with jufi fuch fort of Stone in many of our 
Stone-pits herCy in Inland Countries, It appears to me^ that 
the Water fljould have rather foftned than hardned the Stone 
npon the Shore^ thg by wafhing away the loofer Clayie matter 
and other Earthy fi^ff-i that is fometimes left upon it at the 
it might feem to he a fort Petrification 3 andoxafion 
•this mi flake. 
As to Petrifadions : Ive only obferved thefe three forts. 
ift, A Stony Incruftation upon Stickj and any thing that 
lyes in the w^y^ in the Petrifying Springs 5 the Earth in 
thofk Waters is nfually inter mixt with' particles of Stone,, that 
trickle down into it with the Water ^and are there detain d.^f 
this firft fort you have drntbtlefs many^ inftances in Eflex,^^^^ 
1 think, there is one at Harwich Clijf'-y tho this m my opinion 
is not fo property called a Petrifadion. 2dly. The fecond 
fort is that which is performed by the Permeation or Infinii- 
ation of the ^ner forts of Stony Particles, as it is in the 
cafe of fomeofour Petrifying waters^ {I believe) piirticularly 
$hat at Rnaresborough fomctimes the Stony particles 
N n n n n n n n n 2 hew- 
