ay, and in this way, as it appears to me, the early dyers
learnt the efficacy of what we now call "mordants," which I may
briefly describe as fixing agents for coloring matters.

At a very remote period therefore, I imagine, the subject of fast and
fugitive dyes engaged the attention of textile colorists.

Our European knowledge of dyeing seems to have come to us from the
East, and although at first indigenous dyestuffs were largely
employed, with the discovery of new countries many of these fell
slowly and gradually into disuse, giving way to the newly imported
dyestuffs of other lands, which possessed some advantage, being either
richer in coloring matter, yielding brighter or faster colors, or
being capable of more easy application. Thus kermes gave way to
cochineal, woad to indigo, and so on.

Down to about the year 1856, natural dyestuffs alone, with but one or
two exceptions, were employed by dyers; but in that year a present
distinguished member of this Society, Dr. Perkin, astonished the
scientific and industrial world by his epoch-making discovery of the
coal tar color mauve. From that time down to the present, the textile
colorist has had placed before him an ever increasing number of
coloring matters derived from the same source.

Specially worthy of notice are the discoveries of artificial alizarin,
in 1868, by Graebe and Liebermann, and of indigotin, in 1878, by Adolf
Baeyer, both coloring matters being identical with the respective dyes
obtained from plants.

In view of the vast array of coal tar colors now at our disposal, and
their almost universal application in the decoration of all manner of
textile fabrics, threatening even the continued use of well known
dyestuffs of vegetable origin, it becomes of the greatest importance
to examine most thoroughly, and to compare the stability of both old
and new coloring matters.

The first point in discussing this question of fast and fugitive dyes
is to define the meaning of these terms "fast" and "fugitive."
Unfortunately, as frequently employed, they have no very definite
signification. The great variety of textile fabrics to which coloring
matters are applied, the different stages of manufacture at which the
coloring matter is applied, and the many uses to which the fabrics are
ultimately put, all these are elements which cause dyed colors to be
exposed to the most varied influences.

The term a "fast color," then, may convey a different meaning to
d