( 8 7 o) 
the making of Steel, yet according to the laft and tru- 
eft Procels, the matter is plainly otherwife,« for Iron 
this way made into Steel, becomes a kind of Eleftrum, 
- and is filled with an exceeding brittle and Jiard Body of 
its own Nature Iron being Ipungy and not clofe; for 
which purpofe the refore, the Word denfare is by Pliny 
aptly and elegantly ufed. And this way was ufed when 
the ftrongeft temper and hardnefs was required ; as to 
Picks and Anvils. 
There might be divers reafons given for this laft 
ufage as firft, that there is far greater eafe in work- 
ing Iron, than Steel into any Figure, that being far foft- 
er and more dudtible and loofe. 
Again, it is certain, and the Ancients in the paflage 
laft quoted do teftifie as much, that Iron by ignition is 
ipoilt or corrupted, fo that the oftner it is purged, tho' 
it were Steel it would the more relent. Whence know- 
ing weli, that in making their Tools out of Steel, they 
could not but confiderably loofe it and abate of their temp- 
er ; they therefore firft Ihaped them, and then gave them 
a ftrong Body of Steel and Temper together, and fo 
had nothing elfe to do but to finifti them on the Grind- 
ftone and Hone , tofet the point or edge. 
V, The Defcriptions of certain Shells found in 
the Eaft Indies, Communicated by Mr. Witzen 
to Dr. Lifter, and by him to the Pnblijber y 
with fome Remarks of his own. 
S / /?, 
I Here fent you inclofed an Account of certain Shell* 
and their Figures, which I received from Mr. Witzen y 
formerly Ambaftadour here from the States of Holland^ 
and 
