Part 20 (1/2)

The chronological history of such of these artificial colors which appertain to ink or itsthe dates of their invention and commercial use

The first discovery of ”aniline” is credited to Helot in 1750 In 1825 Faraday in rectifying naphtha discovered benzole, which by the action of strong nitric acid be converted into nitro-benzole; and this latter, when agitated ater, acetic acid and iron filings produced aniline Unverdorben in 1826 discovered an analogous material in products obtained by the destructive distillation of indigo Runge in 1834 claims to have detected it in coal tar and called it kyanol, which after oxidation becament and known as aniline black It could not, however, be used as an ink Zinan in 1840, experi the sa it benzidao with caustic potash developed a product which he also called aniline, the nao Shortly afterwards A W Hoffman established the identity of these substances

Aniline when pure is a colorless liquid, possessing a rather ammoniacal odor It soon becoht and air

It does not affect litmus paper

In 1856 Perkins accidentally discovered the violet dye called mauve, which acquired considerable commercial importance besides its utility for ink purposes

Nicholson in 1862 succeeded in producing the first of the soluble blue anilines

The discovery of induline, one of the modifications of aniline black, was rosine, produced by the action of concentrated sulphuric acid on the insoluble indulines, was discovered in 1868

The soluble indulines and nigrosines differentiate in appearance, the first a bronzy powder and the latter a black lustrous powder When made into ink they possess about equal color values

In 1870 the German chemists, Graebe and Lieber artificial alizarin,--the coloring iven to this discovery until it was put on the h it did not muhl in 1873 obtained an accessory product in the artificial manufacture of alizarin out of anthracene, from which a beautiful blue was made, superior in many respect to the aniline blues It differed fro the same color in solution Alkalis destroyed the color but acids restored it The process was kept a secret for a long tih as 1,500 for a single pound

Caro, a German chemist, invented in 1874 the red color known as eosine, which was brought to this country in the following year and sold for 125 per pound Its color is destroyed by acids

Orchil or archil (the red color) was discovered in 1879 The commercial use of the so-called ”orchil substitutes” (purples) began, however, in the years 1885 and 1887

Artificial indigo, as the result of , cao pure” only in 1897 It had previously been produced synthetically in a variety of ways, but the cost of the production was far above that of the natural product Baeyer and E in 1870, Suida in 1878, Baeyer in 1878, Baeyer and Drewsen in 1882, and Heumann in 1890, can be said to have been the pioneers in the production of artificial indigo

The intensity of some of the aniline colors rain of eosine in ten millions of water exhibits a definite rose-pink color

It is asserted that in the last three years many improvements have been made in the permanent qualities of some of the soluble anilines, but no material which is soluble in plain water should ever be e the discovery of the ”anilines,” as already related, other substances had been employed for ”added” color in the ado, and logwood

Only a casual reference has heretofore been wood

Brazil wood, also called peach wood, is imported froreat antiquity, antedating considerably the discovery of South Aiven to the country on account of the extensive forests of the already well-known 'Brazil wood,' which was found by its Portuguese discoverers The dyestuff thus gave its name to the country from which it was afterwards principally obtained The word 'Brazil' appears to have been originally used to designate a bright red or flana and Ferrara, in 1194, the dyestuff kerrana de Brazile and Brazil wood, both dyestuffs at that ti obtained from India”

For ”added” color to ink and alone it was hteenth centuries

Logwood, employed more extensively for ”added”

color than any other color compound, was introduced into Europe by the Spaniards, A D 1502 In England it does not appear to have been much used until about 1575 In 1581 the Parliament prohibited its use ”because the colours produced froalized in 1673 by an act, the preaenious industry of land the art of fixing, the colours wood, alias blackwood, so as that, by experience, they are found as lasting as the colourshatever” It is obtained principally frorows in the West Indies and South Awood as the base for an ink was a discovery of Runge in 1848, who found that a dilute solution of its coloring matter, to which had been added a small quantity of neutral chromate of potassium, produced a deep black liquid which apparently remained clear and did not deposit any sediment

This composition became very popular on account of its cheapness and dark purple color It is of a fugitive character, though, and has passed almost entirely out of commercial use