Most Viewed

- Browns And The Cold Semi-neutral Grays Marrone Is Practically To
- Also Called Scarlet Chrome Is A Bright Chromate Of Lead Of An
- Black Chalk
- Composition Chemical Analysis Has Shown Several Of The Blues To Be
- Burnt Verdigris
- Belong The Dutch And Flemish Schools; The Sensible Which Aims At
- Less Known As English Red Prussian Red And Scarlet Ochre True
- Olive In Dark Green; Russet And Citrine In Dark Orange The
- Known Likewise As Raw Sienna Earth Terra Di Sienna &c Is A
- Root Of The Anchusa Tinctoria Commonly Known As Alkanet A Plant

Least Viewed

- Their Chief Source The Greens Consist Of Yellow Mixed With Copper
- Only That Of Extreme Light Objects Opaque It Follows That White Is To
- To Which The Various Appellations Have Been Given Of Thenard's Blue
- Thallium Orange
- Distilled Verdigris Or More Properly Refined Verdigris The Best Is
- Molybdenum Green
- Red And Blue In The Proportions Of Five Of The Former To Eight Of
- Violet De Mars Purple Ochre Or Mineral Purple Is A Dark Ochre
- Uniform Colour Thus Composed Is The Citrine Colour Of Fruit And
- Also In The Olive Foliage Of The Rose-tree Formed In The Individual

Body Was Formerly Prepared From Indigo--in Spanish Anil Whence The

name; but is now produced on a larger scale from benzol, a coal-tar
product. As the source of mauve and magenta, aniline must be considered
the parent of coal-tar colours generally. Little was known of it at one
time except that on being mixed with a solution of chloride of lime
there was formed a splendid purple liquid, which immediately gave place
to a dingy reddish precipitate. From the investigation of this simple
fact, however, by Mr. W. Perkin, there was created a new and important
branch of chemical industry--the manufacture of coal-tar colours. The
violet mauve led the way, followed by the red magenta, the blue azuline,
the yellow phosphine, the green emeraldine, the orange aurine, by
purple, and brown, and black. Such were the hues, with many intermediate
tints and shades, which one reaction brought forth. The world rubbed its
eyes with astonishment; and truly it seemed almost as wonderful to
produce the colours of the rainbow from a lump of coal, as to extract
sunshine from cucumbers.

The history of these colours reads more like a romance than a sober
story, but to the artist it is of slight practical interest.
Sufficiently stable as dyes, though they be, coal-tar colours are not
adapted to the palette. Mauve, magenta, with a few others, hare been
introduced as pigments and fairly tried, but a want of permanence has
been fatal to their success. Mauve is more durable than magenta, and the
rest vary in stability, but none of them have proved really fitted for
artists' colours. Exposed to light and air, they all more or less fade,
especially in thin washes; and they have mostly the objection of
staining and permeating the paper or canvas on which they are employed.
Used in body, some may be found eligible in portfolio illuminations and
the like, where the brilliancy of their colours shows to advantage; but
in landscapes and pictures of life, coal-tar pigments are best avoided.

Cakes of red, blue, violet, and other hues, may be prepared for
painting, by combining the colours with a mixture of starch and alumina,
or with soap and alumina in a moist state--thus: 150 parts of white curd
soap, dissolved in 1000 parts of hot water, are mixed with an alcoholic
or a methylated spirit solution of six parts of the crystallized or
solid coal-tar colour. To this are added 250 parts by weight of washed
gelatinous alumina. The whole is then well stirred, collected on a
filter, drained, and dried. Several hues, tints, and shades may be
obtained by compounding: for instance, an orange is produced on
admixture of picric yellow with aniline red, or a green by adding the
same yellow to aniline blue.





Next: Cobalt Reds
Previous: Coal-tar Colours

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