A System of Mineralogy, Volumen2

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A. Constable & Company, 1816
 

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Página 143 - ... in Pentelican marble have been decomposed, and sometimes exhibit a surface as earthy and as rude as common limestone. This is principally owing to veins of extraneous substances which intersect the Pentelican quarries, and which appear more or less in all the works executed in this kind of marble.
Página 143 - Romans, has been already shown ; but, in a very early period, when the arts had attained their full splendour in the age of Pericles, the preference was given by the Greeks, not to the marble of Paros, but to that of Mount Pentelicus: because it was whiter, and also, perhaps, because it was found in the immediate vicinity of Athens.
Página 143 - Micciades, employed this marble, and were imitated by their successors. It receives, with accuracy, the most delicate touches of the chisel, and retains for ages, with all the softness of wax, the mild lustre even of the original polish. The finest Grecian sculpture which has been preserved to the present time, is generally of Parian marble ; as...
Página 291 - The peculiar earth which characterises this mineral (carbonate of strontian) was discovered by Dr. Hope ; and its various properties were made known to the public in his excellent memoir on strontites, inserted in the Transactions of the Royal Society of Edinburgh for the year 1790.
Página 146 - It has a black ground, in which are imbedded fragments or portions of a grayish- white, of a deep red, or of a purple wine color. This is said to be one of the most beautiful marbles hitherto found, and has a superb effect when accompanied with gilt ornaments. Its native place is not known with certainty ; it is conjectured to be Africa. The pedestal of Venus leaving the bath, and a large column, both in the royal museum in Paris, are of this marble. Marbles of the U.
Página 179 - W.) consists of concretions as large often as a small pea, or even larger, the concretions having usually a distinct concentric structure. It is formed in large masses in the vicinity of the Hot Springs at Carlsbad in Bohemia.
Página 172 - ... masses that hang like icicles from the roof, or of strong concretions adhering to the sides of cavities into which the water thus impregnated finds admission; to such deposits the term STALACTITE is applied. " If the percolation of water containing calcareous particles is too rapid to allow time for the formation of a stalactite, the earthy matter is deposited from it after it has fallen from the roof upon the floor of the cavern, and in this case the deposition is called STALAGMITE; the substance...

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