Return of her Nephritick Pains, is, that Oie has never 
followed her Medicine throughly, but upon the third 
Dofe, finding fuch certain Eale, (he gives it over, till a 
new Fit forces her to ufe it again. But however, this ha- 
ving done (b much more for her already , than any 
thing flie ever met with before, flie is fo pleased with it, 
and Ipeaks fuch great things of it, that I believa fihe wili 
foon furnilh me with opportunities enough of giving it 
a fair and fuIlTryal^ and when I know more of it, 
you may expedt to hear further. In the mean time ic 
may not perhaps be amifs for you to be ufmg it your 
felf,- and I dare promife you, that you'll find fome- 
what in it , that will make you fet a Value upon 
it. 
I take this Shell to be that which you call OJiracites 
maximus rugafus & a/per ; and which you have with 
the utmoft exadlneft defcribed. It burns to a Lime as 
other Shells do, and as th^Selenites (tho' weakly) does. 
It fields no Volati! Salt, tho' I try'd it in a naked Fire ; 
nor does common Oyfter-fhells, frefh taken and ufed, 
afford above half a Scruple of a Liquor fomewhat mo- 
derately Urinous, from four Ounces of Shells. And it 
may be, if they were long dryed and expofed to the 
Weather, they would loofe even that, and yield no 
more Volati! Salt than the OJiracites. I confefs I was 
(bmewhat furprized at this matter ; fince there are who 
fiy , that even the other Shells, that are commonly 
Caird petrify'd, yield a Volatil Salt : and I had my felf 
from the Shells of Cruftaceous Fifhes, (particularly of 
Lobfters) had a Volatil Salt and fetid Oyl in no incon- 
fiderable quantity , even in a Sand Furnace. But thefe 
fort of Shells differ from other Shells (as you have ex- 
adJIy obferved) in this too, Quod in his umlo ad cardi- 
»em leviter roftratm efl^ qui tamen in Oftreis paulum ali' 
tsr eft. They differ too in their fpecifick Gravity , 
M 7. thefs 
i 
