Page:Popular Science Monthly Volume 11.djvu/84

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THE POPULAR SCIENCE MONTHLY.

duced the Carystian, Deucalian, Synnadic, and Hierapolitic marbles. The quarries of Tenos are still worked to some extent, but those of Scyros and Naxos remain almost as the ancients left them.

Of the black marbles of antiquity that now called nero antico, or black antique, was the most celebrated. It is more intensely black than any marble now quarried, the black marbles of France appearing almost gray beside it. It occurs only in sculptured pieces, and its origin is unknown; but Faujas discovered a quarry which had been worked by the ancients, about two leagues from Spa, not far from Aix-la-Chapelle, the marble of which closely resembles the ancient specimens. The largest masses known of nero antico are two columns in the church of Regina Cœli at Rome, but there are also some fine specimens in the Museum of the Capitol and in other collections. Some suppose it to be identical with the marmor Lucullum which was introduced at Rome by Lucullus in the first century b. c., according to Pliny from Melos (another reading is Chios), but according to other authorities from Egypt or Libya, whence it is sometimes called marmor Libycum. Pliny says that Marcus Scaurus had pillars of it thirty-eight feet high in the atrium of his house. The Chian marble, a deep, transparent black, sometimes variegated with other colors, was quarried on Mount Pelinæus, in the island of Chios. A fine black marble was quarried on Mount Tænarus, in Laconia, and in the island of Lesbos, and a blue-black marble in Lydia. One of the most beautiful of the antique breccias, the African breccia, has a deep-black ground, variegated with fragments of grayish white and deep red or purplish wine-color. The grand antique breccia consists of large fragments of black marble united by veins of shining white. Columns of this and of African breccia are in the Paris Museum, but their quarries are unknown.

ON THE WONDERFUL DIVISIBILITY OF GOLD AND OTHER METALS.

By ALEXANDER E. OUTERBRIDGE, Jr.,

ASSAY LABORATORY, UNITED STATES MINT, PHILADELPHIA.

IT is both curious and interesting to notice how frequently original investigators, working from different standpoints, and with entirely dissimilar objects in view, will, independently of each other, accumulate a mass of observations corroborative of some one physical law, but which require to be collated in order to reveal their mutual relations.

The motive of this paper is to collect together several observations illustrating the divisibility of gold (made either as the direct