An instrument for measuring the weight of the atmosphere, which enables us to determine the changes of the weather, the height of mountains, &c. It consists of a glass tube hermetically sealed at one end, filled with mercury, and inverted in a basin of mercury; according to the weight of the atmosphere, this mercury rises or falls.
How is the Hermetic seal formed?
By heating the edges of a vessel, till they are just ready to melt, and then twisting them closely together with hot pincers, so that the air may be totally excluded. The word is taken from Hermes, the Greek name for Mercury, the heathen god of arts and learning, and the supposed inventor of chemistry,[9] which is sometimes called the hermetical art; or perhaps from Hermes, an ancient king of Egypt, who was either its inventor, or excelled in it.
[9] See Chapter XVIII., article [Chemistry].
Quicksilver, or mercury, is a white fluid metal, the heaviest except platina and gold; it readily combines with nearly all other metals, and is used in the manufacture of looking-glasses, barometers, thermometers, &c.; in some of the arts, and in the preparation of several powerful medicines. It is found in California, Hungary, Sweden, Spain, China, and Peru. The quicksilver mine of Guança Velica, in Peru, is one hundred and seventy fathoms in circumference, and four hundred and eighty deep. In this profound abyss are seen streets, squares, and a chapel, where religious worship is performed. The quicksilver mines of Idria, a town of Lower Austria, have continually been wrought for more than 300 years. The vapor which is continually arising from the mercury is very hurtful to the miners, who seldom survive many years.
Abyss, a gulf, a depth without bottom.
In what state is Mercury usually found?
Either native, or in the form of ore; it is often found mixed with silver, but more frequently with sulphur in the form of sulphuret, which is decomposed by distillation. Running mercury is found in globules, in America, and is collected from the clefts of the rocks. Mercury has the appearance of melted silver; it is neither ductile nor malleable in this state; it is a substance so volatile, when heated, that it may be evaporated like water; it is always seen in a fluid state, even in temperate climates, as a very small portion of heat is sufficient to preserve its fluidity. It is used to separate gold and silver from the foreign matter found with those metals. Calomel, a valuable medicine, and vermilion, a color, are both preparations of mercury.