247

vpon occason of the Discourse concerning the Lupus marinus
the teeth of wch. fish are supposed to be the load stones -
Dr. Plot Related that he had a lodestone which was not
such a tooth but a reall stone which he himself had
found in Oxfordshire. But this was a softer stone and would
not polish as the other stones -

Dr. King vpon the occasion of Discousing of Pearles and Bezoar
Stones related that he had often found pearles in the stomack
of an oyter and conceiued them to be generated as the Bezo
ar Stones in the stomack of an ox goat :-

Herevpon mr Henshaw Related the way of cleansing pearles
by Dipping a foule pearle in Aqua fortis and /or/ spt. of nitre
wherevpon the pearl would presently Look white and then rubbing
it wth. a cloth all that white coat would come off and the pearle
vnderneath if good would looke orientall and cleer. but that
by often repeating that operation all the shining part of
the pearle might by Degrees be taken off, and that vsually
all ^ /fowle/ pearles had in the middle of them an opacous calculous
matter

He also Related the way of making counterfeit pearles
vsed at /Bolonia/ venice namely by couer /siluering ouer/ guilding Alabaster beades
wth. siluer and Dipping them in a sise made of fish glew -
mr. Hooke Related that he had done the same thing here by taking
Iuory beades insteed of Alabaster and proceeding as before -

mr. Hooke shewd his experiments which were Diuers ways
of making very round and cleer globules of Glasse for micros=
copes wth great ease and very cleer./

Ref: CELL/RS/HF_249  © Centre for Editing Lives and Letters