The precious jewel of the toad, which some critics and commentators have endeavoured to prove its glittering eye, has long been exploded. Our old alchemists believed in the toadstone; we do not. The fable remains in its pristine beauty; but here is one truth equally beautiful, that the adversity of the oyster turns to a jewel so costly and glorious, that monarchs reckon it amongst the records of their houses and conquered provinces. May we ever turn our sorrows and troubles to as good an account; may we ever continue to do so, for assuredly some men do. The best of men are those who are tried by affliction and trouble, or those who have some deep and secret care, which they hide in their hearts, and which makes them wiser and better. Shelley has a theory that poets are made somewhat after the fashion of pearls, or that, at any rate, their poetry is so produced. He sings—
"Most wretched men
Are cradled into poetry by wrong;
They learn in suffering, what they teach in song."
We have very little doubt but that the true poetry from which the world learns anything worth learning is so produced.
There have been other theories as to the production of the pearl, some holding that the interior formation which we state to be a grain of sand, is a dead ovum which the fish attempts to exude. This theory, too, has its supporters.
"If," said Sir Everard Home, "if I can prove that this, the richest jewel in a monarch's crown, which cannot be imitated by any art of man" (he is rather wrong there; it can be imitated, and wonderfully imitated too,) "either in beauty of form or brilliancy of lustre, is the abortive egg of an oyster enveloped in its own nacre, who will not be struck with wonder and astonishment?" Wonder and astonishment are words which scarcely exist now. Science has shown so many wonders that we are hardly astonished at anything; but Sir Everard's assertion admits of proof. A pearl cut in two exhibits the concentric layers like an onion, as may be seen through a strong lens; and in the centre is a round hole, very minute it may be, but wherein the ovum has been deposited.
Sometimes the ovum, or sand, or enclosed substance has attached itself to the shell, and has then been covered with mucus, forming a pearl which cannot be separated from the shell. There are several specimens of such pearls in the British Museum.
The great beauty in pearls is their opalescence, and a lustre which, as we have before observed, however clever the imitation, has never yet been given to artificial pearls. Sir Everard Home supposes that this lustre arises from the highly polished coat of the centre shell, the pearl itself being diaphanous. Sir David Brewster accounts for it by the pearl and mother-of-pearl having a grooved substance on its surface resembling the minute corrugations often seen on substances covered with oil, paint, or varnish. Philosophers are sometimes not very explanatory. Sir David means to say that beneath the immediate polish of the pearl there are certain wavelets and dimples from which the light is reflected. "The direction of the grooves," again to quote Sir David, "is in every case at right angles to the line joining the coloured image; hence, in irregularly formed mother-of-pearl, where the grooves are often circular, and have every possible direction, the coloured images appear irregularly scattered round the ordinary image."
In the regular pearl these are crowded, from its spherical form, into a small space; hence its marvellous appearance of white unformed light, and hence its beauty and value.