Inks, sympathetic

The salts have been used for centuries to produce brilliant and permanent blue colors in porcelain, glass, pottery, tiles, and enamels. It is the principal ingredient in Sevre s and Thenard s blue. A solution of the chloride is used as a sympathetic ink. Cobalt carefully used in the form of the chloride, sulfate, acetate, or nitrate has been found effective in correcting a certain mineral deficiency disease in animals. 

Cobalt(II) acetate is used for bleaching and drying varnishes and laquers. Other applications are as a foam stahihzer for beverages in sympathetic inks as a mineral supplement in animal feed and as a catalyst for oxidation. It also is used in aluminum anodizing solutions. 

Sympathetic Ink. Although die discovery of the cobalt sympathetic ink, which remains invisible until wanned, has often been attributed to Jean Hellot, who first made it known publicly, he was not the first person to prepare it. Hellot himself stated that a German artist of Stol-berg had shown him a reddish salt which, when exposed to heat, became blue. It had been prepared by dissolving Schneeberg cobalt in aqua regia (119). H. F. Teichmeyer of Jena was also familiar with this cobalt ink, perhaps even before Hellot made its composition public in 1737... 

Sympathetic Ink.—By sympathetic ink is meant a fluid which, being employed in writing, does not leave a trace of color upon the paper, but which, when exposed to moisture or heat, or when washed over with some vegetal or mineral solution, or subjected to some other agency according to its nature and chemical characteristics, becomes visible, the characters being then developed in a more or less apparent manner. 

Owing to their change of colour under hydration, cohalt salts have long been used sympathetic inks. ... 

The change in colour undergone by cobalt chloride on varying the temperature is taken advantage of in the preparation of sympathetic inks. 

Use Sympathetic inks, paint and varnish driers, catalyst, anodizing, mineral supplement in feed additives, foam stabilizer. 

Use Absorbent for ammonia, gas masks, electroplating, sympathetic inks, hygrometers, manufacture of vitamin B12, flux for magnesium refining, solid lu-... 

Use Sympathetic inks, cobalt pigments, catalysts, additive to soils and animal feeds, vitamin preparations, hair dyes, porcelain decoration. 

Apparently it was too difficult to provide Wiegleb s book with copper plate engravings colored with sympathetic inks. ... 

The use of sympathetic inks reached a peak in the 18th century. These are solutions of dyestuffs which were said to exert secret effects the most famous is based on cobalt dichloride. They were for example used in the barometer flower which is described as follows by a contemporary writer ... 

If a drawing be made of the trunks and branches of trees in the ordinary manner and a tracing of the leaves with this sympathetic ink, then such a tree appears leafless until it is heated, when it suddenly... 

A GREEN SYMPATHETIC INK, WHICH BECOMES BLUE WHEN HELD OVER A CERTAIN LIQUID AND GREEN... 

Draw a landscape and finish it with sympathetic inks as described in Experiment X, cornfield being painted in and finished with a dilute solution of nitrate of copper. The whole will have a very drear and... 

Acotate of Cobalt. The aectato is obtained by (li.s.solving carbonate of cobalt in acetic acid. Acetate of cribalt forms a. sympathetic ink. (Bee j o. 25 10.)... 

USE For nickel-plating cast zinc, manuf sympathetic ink. The anhydr salt as absorbent for NHj in gas masks. 

OTHER COMMENTS nickel chloride is used for nickel-plating cast zinc used in the manufacture of sympathetic ink anhydrous salt is used as an absorbent for ammonia in gas masks nickel sulfate is used in nickel-plating used as a mordant in dyeing and printing fabrics used in blackening zinc and brass. 

Obtained by dissolving cobalt, or any of its oxides, in hydrochloric acid. The solution is pink, and on evaporation yields beautiful red crystals of hydrated chloride, or possibly hydro-chlorate of the oxide. When dried by heat, the chloride is of a deep blue, but is instantly rendered pink by the contact of water. The crystals are either CoCl, HO, or CoO, HCl. When traces are made on paper with a dilute solution of chloride of cobalt, they are invisible when dry but, when warmed, assume a decided blue colour, which disappears agarlr on cooling, as they again absorb moisture from the air. This is the most beautiful of the sympathetic inks. If iron or nickel be present, the traces appear green instead of blue. 

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