To produce one pound of scales no fewer than 4,000 fishes are required; but this quantity of scales only yields four ounces of pearl essence. The fish are about four inches long; they are sold at a cheap rate in the markets after being deprived of their scales. The value of a pound of washed scales in the Chalonnais is from fifteen to twenty-five livres. The early manufacturers suffered great inconvenience from not knowing how to preserve the scales from putrefaction, and consequently being obliged to use the essence immediately it was obtained, lest it should acquire the intolerable odor of decayed fish. Attempts were made to preserve them in spirit of wine or brandy, but those liquors wholly destroyed their lustre. At length it was discovered that these fishy particles can be kept for a long time in solution of ammonia, and this enables the manufacturers of artificial pearls to carry on a considerable traffic with distant places where the fish is plentiful, the supply from the Seine, though abundant, being insufficient for the purposes of the trade of Paris. Down to a late period, the heirs of M. Jaquin continued to manufacture pearls to a considerable extent, in the Rue de Petit Lion, at Paris. An elaborate account of this art is given by De Beost, in a work entitled, "_L'Art d'imiter les Perles fines_," from which most English descriptions of this manufacture have been obtained. [Illustration: ARTIFICIAL PEARLS IN THE MUSSEL (MYA MARGARITIFERA).] In a recent number of the "Journal of the Society of Arts," it was stated that an "oyster, or rather a mussel, of the species known to naturalists as the _mya margaritifera_, in which the artificial pearls are formed by the Chinese, had recently been sent to England. These pearls are only obtained near Ning-po, and until lately very little was known of the manner in which they were formed; and the account first published by Sir Joseph Banks was generally questioned. The _Hermes_ steamer, however, on a late visit to that place, was able to obtain several live ones, in which, on being opened, several pearls, as many as eighteen or twenty, were found in the course of formation. The one sent only contains simple pearls adhering to the shell. It appears they are formed by introducing some pieces of wood or baked earth into the animal while alive, which, irritating it, causes it to cover the extraneous substance with a pearly deposit. Little figures made of metal are frequently introduced, and, when covered with the deposit, are valued by the Chinese as charms. These figures generally represent Buddha in the sitting position, in which that image is most frequently portrayed. Several specimens have, it is said, been preserved alive in spirits, and others slightly opened, so as to show the pearls." FOOTNOTES: