434 
plint's katueal histoey. 
[Book IX. 
cautions against danger ; the divers, they say, take especial care 
to find these, and when once they are taken, the others stray to 
and fro, and are easily caught in their nets. We learn also 
that as soon as they are taken they are placed under a thick 
layer of salt in earthen- ware vessels ; as the flesh is gradually 
consumed, certain knots/^ which form the pearls, are dis- 
engaged^'^ from their bodies, and fall to the bottom of the 
vessel. " 
CHAP. 56. — THE VARIOUS e:i.nds of peaels. 
There is no doubt that pearls wear with use, and will change 
their colour, if neglected. All their merit consists in their 
whiteness, large size, roundness, polish, and weight ; qualities 
which are not easily to be found united in the same ; so much 
so, indeed, that no two pearls are ever found perfectly alike ; 
and it was from this circumstance, no doubt, that our Eomaii 
luxury first gave them the name of unio,''^^ or the unique 
gem : for a similar name is not given them by the Greeks ; nor, 
indeed, among the barbarians by whom they are found are 
they called anything else but margaritse."^^ Even in the very 
whiteness of the pearl there is a great difference to be ob- 
served. Those are of a much clearer water that are found in 
the Eed Sea,^^ while the Indian pearl resembles in tint the 
scales of the mirror-stone, but exceeds all the others in size. 
The colour that is most highly prized of all, is that of those 
SI " Niicleos." The Greek authors occasionally call them stones" 
and "bones." TertuUian calls them maladies of shell-fish and warts" — 
concharum vitia et verrucas." 
22 Cuvier says, that the most efficient mode of extracting all the con- 
cretions that may happen to be concealed in the body of the animal, is to 
leave the flesh to dissolve in water, upon which the concretions naturally 
fall to the bottom. 
33 Isidorus and Solinus, however, say that the pearl is so called, because 
two are never found together. The derivation given by Pliny is, however, 
the more probable one. From the Latin *'unio," comes our word 
"onion;" which, like the pearl, consists of numerous coats, one laid 
upon the other. 
3* Hence we must conclude that the word *'margarita" is not of Greek, 
but Eastern origin. 
35 ^lian. Hist. Anim. B. xv. c. 8, says, that the Indian pearls, and 
those which come from the Red Sea, are the best. 
36 The laminae of the lapis specularis, described by Pliny, B. xxxvi. 
c. 45. 
