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gure, fometimes roundifh, globular with unequal 
Depreflions, and of a yellowifli white Colour exter- 
nally, and a fmooth polifhed Surface. 
It differs in Magnitude, as it does in Figure, from 
the Bulk of a Pigeons Egg up to four or five times 
that Size. 
They are aioflly compad, ponderous and folid, not 
very friable, but requiring a pretty fmart Blow of a 
Hammer to break them. They yield eafily to the 
Saw j but this defaces their internal Texture, which 
is very remarkably elegant and regular. The Stones 
confift of concentric Coats firmly adhering to each 
other, formed about a Nucleus, which appeared to 
be quite an heterogeneous Subftance, both from its 
Colour, Hardnefs, and Texture. 
-But another obvious Circumftance in its Strudure 
renders the Belluga Stone different from moft 
others, which is its radiated Appearance. It feems 
compofed of an infinite Number of fhining Rays, 
regularly diverging from the central Nucleus to the 
Circumference, reprefenting both in Colour and 
Form the Flakes of a pure white Terra foliata Tar - 
tdri 7 or (excepting the Colour, which is yellowifh) 
the ftriated Spicula of Antimony. 
This Stone is found in the Fifh called the Bel - 
luga 7 a Species of Sturgeon, the Acipenfer tuber - 
culis carens Artedii , Part III. pag. 92. It is com- 
monly called Lapis Bellug£ 7 by the Ruffians Kamen 
Belluga , which ftgnifies the fame thing. 
Of this Fifh feveral Authors have given us the 
following Account s in Shape it is not much unlike 
a Sturgeon, 
