SHE 
luable for their rarity than pearls for their beauty. 
Indeed, it is their fcarcity, and not their beauty, 
that determines the value of all natural curiofi- 
ties. Such Shells as prefent nothing attra£live to 
the ignorant, are often the mofb precious ; and 
thofe which an unlearned fpedlator would confider 
with admiration, an adept in conchology would 
probably pafs over with difdain. Thefe collec- 
tions, however, have their ufes; not only by exhi- 
biting the vaft variety of nature's operations, but 
alfo by exciting our curiofityto the confideration 
of thofe animals that form them. The mind 
which can find innocent entertainment in thofe 
humble contemplations, is not ill employed: for 
what can be more gratifying, fays Pliny, than to 
view Nature in all her irregularities, and fporting 
in all lier variety of Shells! Such a difference of 
colour do they exhibit; fuch a dilVinftion of 
figure i flat, concave, long, lunated, circular, the 
orbit divided: fome are feen with a rifing on the 
back, fome fmooth, fome wrinkled, toothed, 
ftreaked, the point varioufly intorted, the mouth 
pointed like a dagger, folded back, and bent in- 
wards: all thefe variations, and many more, at 
once furnifh novelty, elegance, and fpeculation. 
With refpeft to the figure of Shells, Ariftotle 
has very judicioufly divided them into three kinds ; 
and his method is, of all others, the moft confo- 
nant to nature. Thefe are, firfl:, the univalve, or 
turbinated, confifbingof one piece only; fecondly, 
the bivalve, confifting of two pieces, united by a 
hinge, like an oyfter; and, thirdly, the multivalve, 
compofed of more than two pieces, as the acorn 
Shell. All thefe are found in the fea at different 
depths; and are valuable in proportion to their 
fcarcity and beauty. 
From the variety of the colours and figures of 
Shells, we pafs on to that of their places or fitua- 
tions. Some are found in the fea; others in frefli- 
water rivers ; fome alive on land ; and a ftill greater 
quantity dead in the bowels of the earth. But 
wherever Shells are found, they are univerfally 
known to be compofed of one and the fame fub- 
ftance: they arc formed of an animal or calcarious 
earth, that ferments with vinegar and other acids, 
burns into lime, and will not eafily melt into 
glafs. 
Sea-Shells are either found in the depths of the 
ocean, or, being forfakcn of their inhabitants, are 
by the tide call on the fhores. Thofe which are 
fifhed up from the deep are commonly denomi- 
nated pelagii; and fuch as are cafb on the fhores 
are termed littorales. Many of the pelagii are 
never feen on fhore; but they remain in the depths 
where they were firft produced, and their capture 
is altogether fortuitous: thefe, therefore, are the 
fcarceft,and confequently the moft valuable Shells. 
The littorales are more common; and fuch as 
are of the fame genus with the pelagii are lefs 
beautiful. As they are often found evacuated, 
they frequently lofe the whitenefs and brilliancy 
of their colouring. They are alfo often perfo- 
rated, either by worms, or by each other; and are 
thus rendered lefs valuable: but their eftimation 
is farther decreafed, when they are fcaled, either 
by lying too long empty at the bottom of the fea, 
or expofed on the ihore. However, fea Shells 
exceed either land or folTile Shells in beauty; as 
they receive the higheft polifh, and exhibit the 
moft brilliant and variegated tints. 
Frefti-water Shells are neither fo numerous, fo 
various, or fo beautiful, as thofe which belong to 
the o:ean ; they are deftitute of that folidity which 
SHE 
the latter pofTefs; their clavicles are neither fo 
prominent nor fo ftrong; and being deprived of 
a faline impregnation to tinge their furfaces, their 
colours are very obfcure. There are only two 
kinds found in frefli-water, the bivalved and the 
turbinated. 
Living land Shells are more beautiful, though 
lefs various, than thofe which inhabit frefh wa- 
ters; and fome are not inferior in elegance to 
fea Shells. However, they are but of one kind, 
viz. the turbinated; and of that only four or five 
varieties are celebrated for their beauty. 
Though fofTile Shells do not properly fall 
within the limits of this work, a fhort account of 
them, as being connefted with recent ones, may 
neverthelefs be extremely appofite. This clafs 
contains as many genera as the fea itfelf; the uni- 
valve, the bivalve, and the multivalve kinds; and 
of each of thefe, many varieties not to be found in 
a recent ftate. Indeed, the number is fo great, 
and the varieties are fo many, that naturalifts long 
entertained an opinion that they were the capri- 
cious produ£lions of nature, and had never been 
the retreats of animals whofe habitations they re- 
fembled. They v/ere found not only of various 
kinds, but in diff'erent ftates of prefervacion : fome 
had the Shell entire, compofed, as in it's primi- 
tive ftate, of a white calcarious earth, and filled 
with earth, or even empty; others were difcovered 
with the Shell entire, but replete with a fubftance 
which was petrified by time; fome, and thefe in 
great numbers, were found with the Shell en- 
tirely mouldered away, but the petrified fubftance 
that filled it ftill exhibiting the figure and impref- 
fion of the Shell ; others, which had been lodged 
near earth or ftone, imprcffed their print on thefe 
fubftances, and left the mark, though they them- 
felves were decayed; and, laftly, fome Shells were 
found half mouldered away, their parts fcaling 
off from each other in the fame manner they were 
originally formed. However, thefe different 
ftages of the Shell, and even their fermenting 
with acids, were at firft infufficient to convince 
thofe who had affigned them to a different origin : 
they were ftill confidered as accidental and fpor- 
tive formations; depofited in the various fituations 
where they were difcovered, but unconnected with 
any part of animated nature. Succeeding enquir- 
ers, more accurate in their refearches, on digging 
up petrified Shells or teeth, foon found that they 
could difcover the petrified remains of fome other 
durable parts of the body. They perceived that 
the Shells taken from the earth exhibited the 
ufual defedls and difafters which the fame kinds 
are known to receive at fea: they were not only 
tinftured with a falt-water cruft, but pierced in a 
peculiar manner by the fea-worms, which eagerly 
devour the Shells of fifties. Thefe proofs at laftv 
prevailed over the erroneous opinions of former 
ages; and the falfe hypothefes which had been 
fyftematized, fpeedily died away. 
Wherever Shells are found, they are now confi- 
dered as the fpoils of fome animals that once 
found flieker in them. By what means they have 
wandered from the fea, is not necelTary to be ex- 
plained; they all exhibit unqueftionable marks of 
their origin. From their number and fitviation, 
however, we are led to conjeClure that the fea 
once reached thofe fpots where they are found; 
from their varieties, we learn how little we know 
of all the fea at prefent contains; and it is moft 
probable that thoufands of different fliapes, en- 
tirely unknown, ftill remain at the bottom. 
A variety 
