GLASS is the name of an artificial substance, formed by the igneous fusion of siliceous earth with various salts and metallic oxides, and possessing a high degree of transpa rency, equalled only by the more perfect crystals of the mineral kingdoms, and other physical properties, which render it one of the most useful and ornamental substan ces which the arts have received from the ingenuity of man.
The word glass is of uncertain etymology. It has been derived by some from the word glessum, the name which the ancient Gauls and Germans gave to amber, and from which has arisen the German word gleisser," to shine," and the English word glisten ; while others have traced it to the word glastum, the Latin term for woad, either because the ashes of this plant were used in the manufacture of glass, or because glass had commonly that blue tinge which the Britons communicated to their bodies by the use of the woad. Its derivation from the Latin word glacies, signify ing ice, is not less probable than those which we have men tioned.
It would be a task as irksome to ourselves as it would be unprofitable to our readers, to detail the unfounded specu lations which have been accumulated respecting the origin of this remarkable substance.
There is some reason to believe that glass was made by the Phenicians, the Tyrians, and the Egyptians. Paw and other antiquarians maintain, that the first glasshouse was constructed at Diospolis, the ancient capital of Thebais ; but it appears from the writings of the ancients, that the Phenicians had made considerable progress in the manu facture of glass ; and Pliny informs us that the Phenician colony of Sidon obtained, for some hundred years, the chief ingredients of their glass from the Phenician town Acco, now St John D'Acre, near the place where the small river Belus throws itself into the Mediterranean.
The account of the origin of glass, which Pliny has handed down to us, is extremely plausible. A merchant vessel laden with nitre or fossil alkali, having been driven ashore on the coast of Palestine, near the river Belus, the crew went in search of provisions, and accidentally support ed the kettles on which they dressed them upon pieces of fossil alkali. The river sand, above which this operation was was vitrified by its union with the alkali, and thus produced glass. The important hint which was
thus accidently obtained, was soon adopted, and the art of making glass was gradually improved.* In the time of Pliny, glass was manufactured out of the fine sand which was collected at the mouth of the river Vulturnus. After being ground to powder, it was mixed with three parts of nitrous fossil alkali, or soda, and after fusion it was taken to another furnace, where it was formed into a mass called ammonitrum, and converted into a pure glass. A similar method of making glass was used in Spain and Gaul.
Pliny informs us, that in the reign of Tiberius an artist had his house demolished for making glass malleable, while Petronius Arbiter asserts that he was beheaded by the emperor. About the commencement of the Chris tian era, drinking vessels were commonly made of glass, and glass bottles for holding wine and flowers were in com mon use. The company at Rome which was engaged in the manufacture of glass had a particular street assigned to them near the Porta Capena. Alexander Severus im posed a tax upon this company in A. D. 220, which was continued in the time of Aurelian.
The art of making coloured glass seems to have been coeval with the invention of glass itself. Many of the Egyptian mummies, one of which is in the British Mu seum, are ornamented with beads of variously coloured glass, which could not have been executed without a che mical knowledge of the properties of the metallic oxides. By what processes these coloured glasses were formed, it is not easy to discover, as the ancients were not acquainted with the mineral acids which are now usually employed in the preparation of metallic oxides. Strabo was told by the workmen of Alexandria, that their country produced an ingredient for making coloured glass ; and Seneca informs us, that Democritus introduced into Europe the art of mak ing coloured glass, and of thus imitating the precious stones. But from whatever source this curious art was de rived, it was brought to a high degree of perfection among the Greeks and Romans; and many of the gems were so admirably counterfeited, as to deceive even those who were intimately acquainted with the study of minerals.