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Most Viewed- Browns And The Cold Semi-neutral Grays Marrone Is Practically To
- Black Chalk
- Belong The Dutch And Flemish Schools; The Sensible Which Aims At
- Burnt Verdigris
- Also Called Scarlet Chrome Is A Bright Chromate Of Lead Of An
- Composition Chemical Analysis Has Shown Several Of The Blues To Be
- Less Known As English Red Prussian Red And Scarlet Ochre True
- Known Likewise As Raw Sienna Earth Terra Di Sienna &c Is A
- Root Of The Anchusa Tinctoria Commonly Known As Alkanet A Plant
- Olive In Dark Green; Russet And Citrine In Dark Orange The
Least Viewed- To Which The Various Appellations Have Been Given Of Thenard's Blue
- Or Quercitron Yellow Is What Its Name Implies It Is Dark In
- Browns Grays And All Broken Colours It Is Likewise The Second
- The Third And Last Of The Primary Or Simple Colours Is Blue Which
- Opaque Oxide Of Chromium Green Oxide Of Chromium Chrome Oxide
- Purple Being A Secondary Colour Composed Of Blue And Red It
- To Keep In Mind--the Glow Of Sunshine And The Cool Of Shade
- Lose Sight Of That The Colour Of Shadow Is Always Transparent And
- Neutral Colours Are Three Only White Black And Grey According
- Of Which Black And White Have Been Stated To Be The Opposed
A Mixture Which Is Also Known As Brunswick Green Fine Bright Greens
they are suited to the ordinary purposes of mechanic painting, but are
quite unfit for the artist's craft, chrome yellow reacting upon and
ultimately destroying Prussian blue when mixed therewith. For the
latter, cheap cobalts and ultramarines are preferably substituted,
although they do not yield greens of like power and intensity.
Under the names of English Green, Green Cinnabar, &c., 'new' green
pigments have been from time to time introduced, which have turned out
mixtures of Prussian blue and chromate of lead; not made, however, by
compounding the two, but directly by processes similar to the
following:--A mixed solution of the acetates of lead and iron is added
to a mixed solution of the yellow prussiate and chromate of potash, the
necessary acetate of iron being obtained by precipitating a solution of
acetate of lead by sulphate of iron, and filtering the supernatant
liquid. Or; to a solution of Prussian blue in oxalic acid, first
chromate of potash is added, and then acetate of lead.
By the last process, superior and more permanent chrome greens may be
produced, free from lead, by using chloride of barium or nitrate of
bismuth in place of the acetate of lead. Chromate of baryta, or chromate
of bismuth is then formed, neither of which acts on the Prussian blue.
It should be added that where the latter pigment is present, no green
will serve for painting walls containing lime, as its action alters the
tint of the Prussian blue.
TTITLE HOOKER'S GREEN
is a compound of Prussian blue and gamboge, two pigments possessing a
like degree of stability, and perfectly innocuous to each other. It is a
mixture more durable and more transparent than chrome greens made with
chromate of lead. There are two varieties in common use--No. 1, a light
grass green, in which the yellow predominates; and No. 2, a deeper and
more powerful green, with a larger amount of blue.
TTITLE PRUSSIAN GREEN,
like the preceding, is composed of Prussian blue and gamboge; but
contains a very great excess of the former, and is therefore a
bluish-green of the utmost depth and transparency, verging on black in
its deep washes. Yellow ochre may be employed instead of gamboge, but is
not so eligible.
A true Prussian green, which has been recommended as a pigment, can be
produced as a simple original colour, with a base wholly of iron. It is
got by partially decomposing the yellow oxalate of protoxide of iron
with red prussiate of potash. We have made this green and given it a
fair trial, but our verdict is decidedly against it. In colour it is
far from being equal to a good compound of Prussian blue and gamboge,
and it assumes a dirty buff-yellow on exposure to light and air, the
film of blue on the oxalate more or less disappearing.
Another Prussian green, with a base of cobalt, is obtained by
precipitating the nitrate of that metal with yellow prussiate of potash.
According to the mode adopted, and the degree of heat, either a light or
dark green results; but this also is inferior in colour, and presents no
advantage as to permanence.
TTITLE SAP GREEN,
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