^lv€nti which till then it kept inclofed 
in its Body. 
If there were made an accurate Exa~ 
pt^n oi Angled Bodies, both as to their 
Compofition and their Refolution, we 
might (hortly obtain a certain knowlcdg 
of the Variety of the Motion, with which 
the Particles of the Flpid, as well the 
liibtii^ as the ambient, are agitated: 
Which part of Natural Philofophy as it 
hath been touched by few, fo it is necef- 
fary to' all for the true explication of Na¬ 
tural operations. 
Among Solids naturally included in 
Solids, there is none that occurs more 
frequently, and that hath more doubt in 
it, than the Cockler-pells: 
Wherefore I purpofe to dif- 
courfe IbrnewhatiUorc large” fjf/jr ^ 
ly of them, confidering jirjl 
thofe that are taken opt of the Sea; and 
then thofe, that are digg*d out of Moun¬ 
tains. 
All forts of sheUs^ that once had an 
animal in them, exhibit to our fenfes 
what follows: 
That the whole Shells are refolved 
intd little flwlls, but thefe little fhells 
