ain out of the pulp that
is being carried through by the worm, in order that the pulp may be
introduced into the next chest of the series as free as possible from
the liquid in which it has been suspended while in the chest from
which it is just taken. The pulp is thus conveyed from one chest in
the series to the inlet passage leading to the next chest of the
series, and in the said inlet passage it meets the liquid coming in
the reverse order from the next chest beyond in the series, the pulp
and liquid thus commingling in the inlet pipe and entering the chest
together, and being thoroughly mixed by the agitators in passing
through the chest by the continued action of fresh material entering
and of the conveyors taking the material out from the chests. In the
last of the series of chests into which the pulp is introduced the
fresh or strong bleaching liquid is introduced through a suitable
inlet pipe, _g_, and the pulp conveyor, _f_, that takes the pulp from
the last chest, delivers it into a pipe, _h_, by which it may be
conveyed to any desired point, the said pulp having been sufficiently
bleached before arriving at the said pipe, _h_. It will be seen that
by these means all the pulp is thoroughly and uniformly subjected to
the bleaching agent and that the bleaching is gradually performed in
all parts of the pulp, which is first acted upon by the weaker
bleaching agent that has previously operated upon the pulp before
treated, and that finally, when nearly bleached, the pulp is acted
upon by the bleaching material of full strength, this action being far
more efficient than when the materials are simply mixed together, the
unbleached material with the strong bleaching agent, and allowed to
remain together until the bleaching operation is finished, in which
plan the bleaching agent loses its strength as the bleaching operation
approaches completion, so that when the pulp is nearly bleached it is
operated upon by a very weak bleaching agent. By having the pulp
transferred from one chest to the next in the reverse order to that in
which the liquid is transferred it will be seen that all parts of the
pulp are acted upon uniformly and equally and that the operation may
go on continuously for an indefinite period of time without
necessitating stopping to empty the vats, as is the case when the
liquor only is transferred from one vat to the next. A pump may be
used for lifting the bleaching liquid, as shown, for example, at _