Forty Centuries of Ink / Or, A chronological narrative concerning ink and its backgrounds, introducing incidental observations and deductions, parallels of time and color phenomena, bibliography, chemistry, poetical effusions, citations, anecdotes and curiosa together with some evidence respecting the evanescent character of most inks of to-day and an epitome of chemico-legal ink.

by David Nunes Carvalho

The discovery of induline, one of the modifications of aniline black, was made known in 1864.

Nigrosine, 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 Liebermann, announced that they had succeeded in producing artificial alizarin,—the coloring matter of the madder root. Commercial value was not given to this discovery until it was put on the market in 1873, although it did not meet all the requirements.

Springmuhl 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 from aniline in having the same color in solution. Alkalis destroyed the color but acids restored it. The process was kept a secret for a long time. This product was originally sold as high 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 many years of experimenting, came into commercial use under the name of "indigo 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 Emmerling 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 may be indicated by the fact that a single grain 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 employed as an ink for record purposes.