Pigment The [greek: Kinnabari] Of The Greeks And The Minium--a Term





now confined to red lead--of older writers. Pliny states that it was so

esteemed by the Romans, as to have its price fixed by express law of

state. Among other places, the natural product is met with in

California, Spain, and Peru; and in China there is a native cinnabar so

pure as only to require grinding to become very perfect vermilion.

Whether the natural possesses any advantages over the artificial,

appears to admit of doubt: Bouvier thought that the former blackened

more than the latter, and others coincide with him. As, however, native

vermilion has become commercially obsolete, the question of their

comparative permanence is of little importance. Theoretically, it is

difficult to assign a reason why there should be any difference between

the two.



Vermilion is capable of being made by both wet and dry processes, but

the last are almost exclusively adopted on a scale, and are, we

believe, preferable. Our opinion, expressed with some diffidence, is,

that pigments whose colour depends on the union of sulphur with a

metal--such as vermilion and cadmium yellow--are more stable when the

sulphur is forced to bite into the base. This can only be effected by a

considerable degree of heat, far greater than can be obtained in any

moist method. We hold that in pigments so produced, the sulphur is less

liable to oxidation by air and light, and that therefore the colour

better withstands exposure to those agents. Before now, vermilions have

been taxed with fading in a strong light: supposing them genuine, it

would be interesting to know by what mode they were manufactured.



There are two kinds of vermilion in common use, European and Chinese, of

which the first inclines to orange and the second to purple. These





Pigment Says The Chemical News Supplies A Desideratum Hitherto In Pigments And Bases Are Subject To Deoxidation Or To A Loss Of Oxygen facebooktwittergoogle_plusredditpinterestlinkedinmail

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