Bright scarlet

Scarlatiniform rash Bright, scarlet-colored skin eruption that occurs in patches over the entire body with eventual peeling as a result of streptococcal infection. 

This is a bright scarlet shade metallized azo pigment with a chemical constitution which is not yet published. This pigment is predominantly useful in plastic applications that do not require exterior weatherfastness. 

Analysis. The bright scarlet flame color of Sr indicates that atomic emission and absorption methods wiU be good for its analysis. Sr is quantitatively determined by colorimetry down to 200 ppm using chloranrlic acid, by atomic absorption spectroscopy (AAS) to 100 ppb, to 1 ppb by electrothermal absorption spectroscopy (ETAS), and to 0.1 ppb by inductively-coupled plasma emission spectroscopy (ICPES) and inductively-coupled plasma mass spectroscopy (ICPMS). A spot test for Sr which extends to 40 ppm is provided by K2Cr04 and sodium rhodizonate. 

The union of mercury and sulfur is effected in the most simple way of all by merely rubbing the two substances together. The product is a black, amorphous compound, quite unlike the bright scarlet crystalline mineral cinnabar. To convert it into the crystalline form, advantage is taken of the following principle An amorphous form is more unstable than a crystalline form and tends to go over into it. The unstable amorphous form is also more soluble in solvents than the stable crystalline form. If, therefore, a solvent can be found in which both are slightly soluble, the amorphous form dissolves to saturation, but this produces a solution oversaturated with respect to the stable form, and some of this crystallizes out. More of the unstable... 

This is an oxide of lead with a composition corresponding approximately with the formula Pb,04 (— PbOif 2PbO). It forms a bright scarlet heavy powder with various gradations of colour according to the method of preparation a variety with a much paler colour than that of ordinary minium is termed orange lead. 

Procedure Spread 25 grams of lead monoxide in a thin layer on an iron or aluminum plate 2-4 mm. thick. Either use the variety of lead oxide which has not been fused and is known under the name of massicot, or use lead carbonate, which on being heated yields a very pure and finely divided lead monoxide. Heat the lead oxide over a ring burner so adjusted that the flames do not quite touch the metal plate. The plate must be kept just below a perceptible red heat. Continue the heating for 6 hours or more and turn over the powder frequently with an iron spatula. When the change is complete, the product is dark brown when hot, a bright scarlet-red when partly cooled, and a somewhat less brilliant red when entirely cold. 

Color Silver-white (liquid metal) tin-white White (solid mercury) Black or grayish-black (mercuric sulfide, black) bright scarlet-red blackens on exposure to light (mercuric sulfide, red) White... 

A solution of congo red is blue in the presence of acids and red in the presence of bases. The dye colors cotton a bright crimson red, but the color is not permanent wool is dyed a bright scarlet. 

The pregnant female cochineal bug produces the brilliant red dye that became the first product ever exported from the New World to the Old. Soon, Europeans were dying their wool and silk with the insect extract. Maybe the most memorable use of cochineal was the bright scarlets for which the Gobelin tapestries of Paris became famous. 

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