nt from
sea water and stowing it away in this peculiar form is "one of those
things no fellow can find out." But according to the chemist the Murex
mollusk made a mistake in hitching the bromine to the wrong carbon
atoms. He finds as he would word it that the 6:6' di-brom indigo
secreted by the shellfish is not so good as the 5:5' di-brom indigo now
manufactured at a cheap rate and in unlimited quantity. But we must not
expect too much of a mollusk's mind. In their cheapness lies the offense
of the aniline dyes in the minds of some people. Our modern aristocrats
would delight to be entitled "porphyrogeniti" and to wear exclusive
gowns of "purple and scarlet from the isles of Elishah" as was done in
Ezekiel's time, but when any shopgirl or sailor can wear the royal color
it spoils its beauty in their eyes. Applied science accomplishes a real
democracy such as legislation has ever failed to establish.

Any kind of dye found in nature can be made in the laboratory whenever
its composition is understood and usually it can be made cheaper and
purer than it can be extracted from the plant. But to work out a
profitable process for making it synthetically is sometimes a task
requiring high skill, persistent labor and heavy expenditure. One of the
latest and most striking of these achievements of synthetic chemistry is
the manufacture of indigo.

Indigo is one of the oldest and fastest of the dyestuffs. To see that it
is both ancient and lasting look at the unfaded blue cloths that enwrap
an Egyptian mummy. When Caesar conquered our British ancestors he found
them tattooed with woad, the native indigo. But the chief source of
indigo was, as its name implies, India. In 1897 nearly a million acres
in India were growing the indigo plant and the annual value of the crop
was $20,000,000. Then the fall began and by 1914 India was producing
only $300,000 worth! What had happened to destroy this profitable
industry? Some blight or insect? No, it was simply that the Badische
Anilin-und-Soda Fabrik had worked out a practical process for making
artificial indigo.

That indigo on breaking up gave off aniline was discovered as early as
1840. In fact that was how aniline got its name, for when Fritzsche
distilled indigo with caustic soda he called the colorless distillate
"aniline," from the Arabic name for indigo, "anil" or "al-nil," that is,
"the blue-stuff." But how to reverse the process and get indigo from
aniline puzzled chemists for