( 14 21 ) 
the Sea-fifhes, which tho they fwim in Salt Water, and 
always receive the fame into their Stomach and Bowels 
yet none of the Salts mix with their Blood, but coagu- 
late in fuch a manner in the Stomach and Guts, that they 
affume the figure- of Diamonds, and pafs through their 
Bodies, together with the Excrements. 
In fhort, we may conclude, that Pearls are ufelefs, and 
that there is no manner of advantage to be had from them 
in the way of Medicines, and confequently that they are 
good for nothing elfe but to empty Rich Mens Pockets of 
their Money 3 and I tnuft needs own that I have the 
fame opinion of Gold too, tho I have often heard that 
mightily cry’d up by fome People, and fo again is Silver 
by others. 
But thofe that have diffolved Gold and Silver, and • 
know how they coagulate again, and confider moreover, 
that Gold is 18, and Silver 10 times heavier than our 
Blood 3 they know, that altho Gold and Stiver could en- 
ter into the Blood, (which yet is unconceivable , ) it can 
never be afiimilated or mingled therewith 3 now if this be 
true, ’tis plain that the aforefaid Mettals do only ferve to 
enrich thofe that prefcribe them. 
To return again to the bufinefs of the Pearls 3 1 view’d 1 
them again with my Microfcope, and obferved that the 
fealey Particles, of which the Pearls were compofed, were 
much thinner than they had appeared before. 
I imagined alfo, that in fome of the Pearls, I could 
fee the very place, where they had been joined to the 
Shell, and at which they received their Nourilhment- 
and encreafe, which I fuppofe to happen after the 
fame manner, as the Gall-Nuts are produced upon the 
Leaves of Oaks 5 that is to fay from a fuperfluity of 
Matter , or elfe from Wounds or Obftrudions in the 
Veffels. 
Now, fince Pearls are produced as it were accidenti- 
dly ( and after the manner abovementioned) in the Shells 
of 
i 
a* 
