d production of figured dress
fabrics with the ground in one fibre (wool) and colour, and the design
in another fibre (cotton) and colour. The number of direct dyes issued
by the various colour manufacturers is so great that it would take a
fairly considerable space to discuss them all.

To obtain good results it is needful that the dyer of union fabrics
should be a man of keen observation and have a thorough knowledge of
the dyes he is using, for each dye makes a rule to itself as regards
its power of dyeing wool and cotton; some go better on to the (p. 169)
cotton than on to the wool, and _vice versa_. Some dye wool best
at the boil, others equally well below that heat; some go on the
cotton at a moderate temperature, others require the dye-bath to be
boiling; some will go to the cotton only and appear to ignore the
wool.

The presence or absence in the dye-bath of such bodies as carbonate of
soda, Glauber's salt, etc., has a material influence on the degree of
the affinity of the dye-stuff for the two fibres, as will perhaps be
noted hereafter. Again, while some of the dyes produce equal colours
on both fibres, there are others where the tone is different. With all
these peculiarities of the Diamine and other direct dyes the union
dyer must make himself familiar. These dyes are used in neutral baths,
that is, along with the dye-stuff. It is often convenient to use along
with the direct dyes some azo or acid dyes which have the property of
dyeing the wool from neutral baths; many examples of such will be
found in the practical recipes given below. The dyes now under
consideration may be conveniently classed into five groups.

(1) _Those dyes which dye the cotton and wool from the same bath to
the same shade, or nearly so._--Among such are Thioflavine S, Diamine
Fast Yellow B, Diamine Orange B, Diamine Rose B D, Diamine Reds 4 B,
5 B, 6 B and 10 B, Diamine Fast Red F, Diamine Bordeaux B, Diamine
Brown N, Diamine Brown 3 G, B and G W, Diamine Blue R W, B X, Diamine
Blue G, Diamine Greens G and B, Diamine Black H W, Diamine Dark
Blue B, Union Black B and S, Oxydiamine Blacks B, M, D and A, Diamine
Catechine G, Union Blue B B, Oxyphenine, Chloramine Yellow,
Thioflavine S, Alkali Yellow R, Chromine G, Titan Scarlet S, Mimosa,
Primuline, Auroline, Congo Corinth B, Thiazol Yellow, Columbia Yellow,
Oxydiamine Yellow G G, Oxydiamine Oranges G and R, Diamine (p. 170)
Orange O, Oxydiamine Red S.

(2) _Dyes whic