Paint Its Colouring Matter Or Anchusin Has The Character Of A Resin





and is dark-red, softened by heat, insoluble in water, soluble in

alcohol and alkalis, and freely so in ether, fats, and volatile oils, to

all of which it imparts a brilliant red hue. To obtain anchusin, all the

soluble matters are first abstracted from the bruised root by water: it

is then digested in a solution of carbonate of potash, from which it may

be readily precipitated by an acid. Its alcoholic solution yields with

different reagents crimson, flesh-coloured, blue, and violet

precipitates, none of which, however, can be classed as durable. The

variety under notice, violet carmine, resembles the other colours

afforded by alkanet in not being able to withstand the action of light.

On continued exposure, it loses its beauty and brightness, together with

much of its colour, and, like Indian purple, assumes an inky blackness.

Hence it is unsuited to permanently pure effects, and should only be

used in body.



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Oxide Of Manganese Which Gives The Red Hue And That Of Cobalt Which Pale Chrome And Deep Chrome Are Chromates Of Lead In Which The facebooktwittergoogle_plusredditpinterestlinkedinmail

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