etc., with diluted aquafortis (nitric acid). A skilled dyer can
perform this operation without the least injury to the goods. This liquor
is kept in stoneware, or a vessel made of caoutchouc composition, or a
large stone hollowed out of five slabs of stone, forming the bottom and
four sides, braced together, and luted with caoutchouc, forming a
water-tight vessel. The latter is the most convenient vessel, as it can be
repaired. The others when once rent are past repair. The steam is
introduced by means of a caoutchouc pipe, and when brought to the boil the
pipe is removed. After the colors are discharged, rinse through three warm
waters. They are then ready to receive the mordant and the dye.

_Note_.--The aquafortis vessel to be outside the dye-house, or, if inside,
to be provided with a funnel to carry away the nitrous fumes, as it is
dangerous to other colors.

_Preparation or mordant for eight dresses, silk and wool mixed, for black._

4 lb. Copperas.
1/2 " Bluestone.
1/2 " Tartar.

Bring to the boil, dissolve the copperas, etc., shut off steam, enter the
goods, handle gently (or else they will be faced, i.e., look gray on face
when dyed) for one hour, lift, air, rinse through three warm waters.

To prepare dye boiler, bring to boil, put in 8 lb. logwood (previously
boiled), 1 lb. black or brown oil soap, shut off steam, enter goods, gently
handle for half an hour, add another pound of soap (have the soap dissolved
ready), and keep moving for another half hour, lift, finish in hand-heat
soap. If very heavy, run through lukewarm water slightly acidulated with
vitriol, rinse, hydro-extract, and hang in stove. Another method to clear
them: Make up three lukewarm waters, in first put some bleaching liquor, in
second a little vitriol, handle these two, and rinse through the third,
hydro-extract, and hang in stove.

_Note_.--This is the method employed generally in small dye-works for all
dresses for black; their lots are so small. This preparation can be kept
up, if care is taken that none of the sediment of the copperas (oxide of
iron) is introduced when charging, as the oxide of iron creates stains.
This also happens when the water used contains iron in quantity or impure
copperas. The remedy is to substitute half a gill of vitriol in place of
tartar.

_Silk, wool, and cotton mixed dresses, for black_.--Dye the silk and wool
as before described, and also the cotton in the manner previously
mentioned.

_A