rt, that they are in every way inferior to the old wood or vegetable
dyes. These charges are unfounded. One of the best refutations is, that
two of the oldest and fastest of natural colouring-matters, viz. alizarin
and indigo, are coal-tar products. There are some coal-tar dyes which are
not fast to light, and there are many vegetable dyes which are equally
fugitive. If there are natural colouring-matters which are fast and which
are aesthetically orthodox, these are rivalled by tar-products which fulfil
the same conditions. Such dyes as aniline black, alizarin blue, anthracene
brown, tartrazine, some of the azo-reds and naphthol green resist the
influence of light as well as, if not better than, any natural
colouring-matter. The artificial yellow dyes are as a whole faster than
the natural yellows. There are at the present time some three hundred
coal-tar colouring-matters made, and about one-tenth of that number of
natural dyes are in use. Of the latter only ten--let us say 33 per
cent.--are really fast. Of the artificial dyes, thirty are extremely fast,
and thirty fast enough for all practical requirements, so that the fast
natural colours have been largely outnumbered by the artificial ones. If
Nature has been beaten, however, this has been rendered possible only by
taking advantage of Nature's own resources--by studying the chemical
properties of atoms, and giving scope to the play of the internal forces
which they inherently possess--

"Yet Nature is made better by no mean,
But Nature makes that mean: so, o'er that art,
Which, you say, adds to Nature, is an art
That Nature makes."

The story told in this chapter is chronologically summarized below--

1820. Naphthalene discovered in coal-tar by Garden.

1832. Anthracene discovered in coal-tar by Dumas and Laurent.

1834. Phenol discovered in coal-tar by Runge.

1842. Picric acid prepared from phenol by Laurent; manufactured in
Manchester in 1862.

1845. Benzidine discovered by Zinin.

1859. Corallin and aurin discovered by Kolbe and Schmitt and by Persoz;
leading to manufacture from oxalic acid and phenol.

1860. Synthesis of salicylic acid by Kolbe.

1864. Manchester yellow discovered by Martius, leading to manufacture of
alpha-naphthylamine and then to alpha-naphthol.

1867. Magdala red discovered by Schiendl.

1868. Synthesis of alizarin by Graebe and Liebermann, leading to the
utilization