Northern Wisconsin advertiser. [volume] (Wabeno, Wis.) 1898-1925, 1912-08-30
But doth suffer a sea change
Into something rich and strange.

But doth suffer a change
Into something rich and strange
We see that in Shakespeares time men had
peculiar notions about the wonders wrought by
the animals of the Again, in Moores poem
Pert and the Pearl" we find:
And precious the tear as that sky
Which turns into pearls 1T falls in the sea-
Aelian thought that pearls were produced by
lightning flashing into the open shells.
Turning from these fantastic, though interest
Ing theories let us glance at the modern ex
plantations of the formation of these beautiful
products Of nature.
You have, no doubt, often shells OF
molluscs lined with smooth anr iridescent coat
ing which is called nacre mother-of-pearl
This coating. like the rest of the shell, Is pro-
duced by the animal, and is made up mostly of
carbonate of lime and an organic matrix which
usually presents a laminated texture. You must
have noticed that the color and briliancy OF this
layer differ in various species of shells. For
instance In the ordinary oyster 1t Is Of lustre-
less white and In kind of shell called abalone
or ear shell (Haliotis), the nacre is of green
ish blue tinge, changing to purple as you turn 1t
in your hand. In another kind. known as the
black-lpped-shel (Margaritifera), the mother-of-
pearl is Of a greenish black color. In the shells
of the true pearl-oysters the uacre is of clear,
delicate white which has the sheen of floss silk
family tinted with azure exhibiting beautiful
play of color-a quality which makes these shells
of great value in commerce
Now 1t often happens that foreign substances,
such as sand grains, microscopic organisms Of
various kinds, parasitic worms, crabs, or some
times even small fishes become introduced by &C
cident or otherwise inside the shell or into the
tissues of the mouscs soft body. In such cases.
the animal sometimes begins to deposit part OF
the material which goes to form the nacreous
layer of the shell around over these foreign
objects and as new material is added year after
year In the form of layers these concretions
which may at first be very tiny grow to be OF
q considerable size. And when this takes place
In a shell with specially beautiful nacre such as
that of the pearloyster, the result may be an OBJ
ject Of great beauty priced from ancient times as
a priceless jewel. In this strange way, pearls,
the handsomest products of nature produced.
Such being their origin, pearls may be formed
In any kind of mollusc, bibalyed or spiral. And
Just as the nacre of different kinds of shells diff
fers so the pearls themselves vary according to
the shell. which produces them Thus the pearls
of the common oyster the scallop and the giant
clam, are milky white and not very bright while
those of the sea mussel are usually black.
Perhaps you have noticed that pearls are of
many different shapes, some round, some pear
of fantastic shapes The round, pear-shaped and
egg-shaped ones are known as oriental or virgin
pearls, while those of irregular shapes are called
baroque pearls. These sometimes found In
the shapes OF fishes, birds wings. creeping
worms. The seed pearls, which are generally
use for medicinal purposes by the Chinese. are
always very small and usually found together
IN numbers.