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- 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

- Sometimes Called China Or Chinese Ink Is Chiefly Brought From
- Red On The One Hand And Of The Middle Tertiary Russet On The
- Distilled Verdigris Or More Properly Refined Verdigris The Best Is
- Molybdenum Green
- Uniform Colour Thus Composed Is The Citrine Colour Of Fruit And
- Or Lamblack Is A Smoke Black Being The Soot Procured By The Burning
- While We Avoid The Compounding Of Contrasting Colours That Is The
- Only That Of Extreme Light Objects Opaque It Follows That White Is To
- And By Mixing Colours Or Tints With Black He Gets Shades It Is A
- Secondary Colours Are Three Only Orange Green And Purple

Of These There Are Three Tints Deep A So-called Pale And Lemon

TTITLE DEEP CADMIUM.

Cadmium Yellow is comparatively a recent introduction, the metal itself
not having been discovered till 1818. The cadmium yellows of commerce
are (the chromate excepted) all sulphides, and therefore not affected by
impure air. Until lately, they were not manufactured in England but
imported from abroad, and as a rule were sadly doctored. We have found
in them a large proportion of orpiment, chromate of lead, &c., together
with quantities of soluble salt, extracted by boiling water. Owing to
careless preparation, there was also present an unnecessary amount of
dirt, which interfered as much with the purity of the colour, as
sophistication lessened its stability. For these reasons, doubtless,
cadmium yellows got to be regarded by some with disfavour and suspicion;
and it may fairly be said that they did not attain their present
popularity, until they became an article of home produce.

Deep cadmium yellow, if genuine, may without hesitation be declared
permanent, both with respect to foul gas, and exposure to light or air.
The variety under notice is of extreme depth, inclining to orange,
glowing, lustrous, and brilliant. It is not very transparent, but
wonderfully clear and bright, of great power, and the most richly toned
yellow known. For draperies it is particularly adapted, and for gorgeous
sunsets is invaluable. It works and washes well, readily throws all
other yellows into the shade when used alone, and combines admirably
with Chinese white for the light touches of bright clouds or mountains.

By admixture with white, cadmium gives a series of beautiful clear
tints. When compounded with white lead, however, the colour has been
stated to be destroyed. Theoretically, this might very well happen.
Cadmium yellow is composed of cadmium and sulphur--white lead of lead
and carbonic acid. If the former parted with some of its sulphur to the
latter, sulphide of lead would result, which is black. Hence, the partly
decomposed yellow and white would be mixed with black, and there would
be formed a blackish-yellow or a yellowish-black. Again, if the cadmium
parted with the whole of its sulphur to the lead, receiving in exchange
the carbonic acid of the latter, a mixture of black sulphide of lead
with white carbonate of cadmium would be furnished, the result being a
grey. Perhaps the following rough diagram may serve to make our meaning
plainer:--





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