nzene.
" " Orthoamidoazotoluene.

The most important of the naphthol colours is undoubtedly
paranitroaniline red, produced by the combination of paranitroaniline
and beta-naphthol. In order to produce the best and brightest shades
these two bodies must be quite pure. The following directions may be
followed:--

=Dyeing Paranitroaniline Red on Yarn.=

It unfortunately happens that this red does not admit of being worked in
large quantities at a time, particularly in the diazo bath where the
colour is developed, as the previous operations seem to render the yarn
slightly waterproof, and hence if large quantities of yarn were dealt
with at one time some would be found to be dyed all right, others would
be defective. It has, therefore, been found best to work only about 2
lb. of yarn at a time, carefully carrying out each operation with this
quantity. As, however, the process can be quickly worked it follows that
in the course of a day a fairly large quantity of yarn can be treated.

1. _Grounding._ The grounding or preparing bath for 100 lb. of yarn is
best made in the following manner: 4 lb. of beta-naphthol are stirred in
2-1/2 lb. of caustic soda liquor 70 deg. Tw., then 1-1/2 quarts of boiling
water is added, when dissolved 1-1/2 quarts of cold water. In a separate
vessel dissolve 5 lb. Turkey-red oil in 11 quarts of water, then mix the
two liquors together and add sufficient water to make up the whole to 12
gallons.

In working sufficient of this liquor is taken and put into a deep tub in
which 2 lb. of yarn can be conveniently worked. It is best to work at a
tepid heat, say 100 deg. to 110 deg. F.; 2 lb. of the yarn are worked in this
liquor, so that it becomes thoroughly impregnated, then it is gently
wrung out and hung up. This operation is repeated with each 2 lb. until
the whole 100 lb. has been treated, adding from time to time some of the
naphthol liquor to make up for that taken up by the cotton. When all the
yarn has been through the liquor, give it another dip through the same
liquor. Place the yarn in a hydro-extractor for five to seven minutes.
Next open out the yarn well, and hang on sticks and dry in a stove at
140 deg. to 150 deg. F. The stove should be heated with iron pipes, through
which steam at 30 lb. to 40 lb. pressure passes. This stove should be
reserved entirely for this work, for if other goods be dried in it along
with the naphthol-prepared cotton, any steam