( 3^1 ) 
VIII. A Lettlr from Sir Robert Sibbald 
, Dr. Martin Lifter Ct^lZ. Med Land. & S. R. S. 
containing an Account of federal Shells obfer^ 
^ed by hm in Scotland- 
I Received yours, and the Exercit at tones M€itcimks\ 
for which I give you many thanks. lam perfwaded 
the Method yon take for promoting Learning is the 
beft, your joining the Antient and Modern Learning 
together, in my Opinion doth both illuftrate and ad- 
vance our Art. Your kte pieces, I hope, will prevail 
with fome to abate of that Contempt they had of the 
Ancient Phifitians ; your Explaining in your Exercitu 
tio Anatomka Tertia^ the way the Stone is produced 
in the Bladder, from the way that Shells and Pearls are 
produced, and from the Petrifications that are made by 
Mineral Waters is moft fatisfying in my Opinion, and 
preferable to what I havefeen Written by any other, f 
have feen fome of the Stones taken out of the Bladder 
broak, which confided of many Coats, like the Skins 
of an Onion. We have fooie Waters that Petrifie. 
Upon the North fide of the fir/i of Forth^ fome eight 
Miles from the City, there is a Cove clofe upon the 
Sea, the Roof of which is covered with a StalagmitH 
a Foot deep, like the Fringe of a Bed; the upper coat 
is of a Sea-colour, the Juice is as white as the Sal Pru- 
nella; the Water which droppethfrom it, if it touch 
the Skin, maketh it fmart : Near to this fame Cove, is 
a piece of an Hollow Rock ; which within, from the 
top to the bottom^ is full of fo many orders of Columns, 
refembling the Pipes of a Church-Organ, and fome of 
different Figures ; I broke a (mall one and found fome- 
what 
