enquiry into the caufes of them, whether they proceed 
from Miner alTinUures^ as we kclead is whitened hy Ft' 
negar , blackt by Oyl, burnt to a Yellow &c. he feems 
to incline to the opinion that they are meerly Accidental, 
and produces experiments to juftifie the Aflertion. 
After this, he enumerates the different Proprieties, and 
ufes may be made of Shell-fijh, and gives us a general Ac- 
count of feveral Mufteumr, in which are to be feen great 
and curiousColled:ions of them, as that of Wormius at Am- 
Jierdam, of Calceolarius, the Mufceum Cofpianum annexed to 
that of Aldrovandus at Bologna , 5cc. At ^me , he 
tells us of many colled:ions of this nature j as in the 
Palace of Prince Pamphilio-, the MufAum of Cardinal 
Chigi, the Study of the ^u^en of Swedens Antiquary, and 
many others. 
His fecond Part contains a plain and fuccinitDefcrip- 
tion of the feveral jpecies contained under each genus ; 
to which are added their colours, the places where they 
are found and whatfoever is particular in each of them, 
which defcriptions refer you to the fourth part of his 
book,- confifting wholly of the figures of them curiouf- 
ly engraven. 
The third part is intirely problematical, where he en- 
quires about the generation of Pearls, and in w^hat 
kinds of Shell-fijh they are founds whether the matter 
they are formed of bethe^^fp- whether they grow from 
the shell, or are produced in the body of the Fiih, as 
alfo whether they are difeafes of them, or their proper 
f^tus. 
He examines the reafon why Shell-fijb are produced ra- 
ther in the 5^«, than in Lakes, or levers-, as alfo why 
more in the Water than in the Earthy Z^c. why there 
is 
