cannot be used when it is desired to
preserve the tint of the woolen under treatment. In this case recourse
is had to the dry process, which consists in substituting the vapors of
nitric acid heated to 115 deg. or 125 deg. for the sulphuric acid. The
arrangement of the rooms must likewise be different. The chambers, which
may be in duplicate, as in the preceding case, are vaulted, and are
about three yards long by three wide and three high. The rags are put
into wire cages that have six divisions, and that are located in the
middle of the chamber, where they are slowly revolved by means of
gearings. Under the floor are the heating flues, and upon it is a
reservoir for holding the vessel that contains the acid to be vaporized.
The arrangements for the admission of air and carrying along the vapors
are the same as in the other case. Great precaution should be taken to
have the flues so constructed as to prevent fire.--_Bull, de la Musee de
l'Industrie_.

* * * * *

APPARATUS FOR EVAPORATING ORGANIC LIQUIDS.

According to Mr. D'A. Bernard, it is especially important, in the dry
distillation of distiller's wash in a closed vessel, for the production
of methyls, ammonia, acetates, and methylamine, that the mass shall be
divided as completely as possible, since it then takes but a relatively
moderate heat to completely destroy the organic coloring matter
contained in the wash. The apparatus shown in Figs. 1 and 2 is based
upon this observation.

The wash enters, through the hopper, D, and the valve, z, a long boiler,
B, which is heated by the furnace, F, through the intermedium of a
waterbath, w. An agitator, E, moves the mass slowly to the other
extremity of the boiler, from whence it makes its exit in the form of
dust. To the frame, E, are fixed the scrapers, b, and the interrupted
pieces, a, in front of which are the hinged valves, c. In the motion of
the pieces, a, from right to left, these valves free the apertures
thereof and allow the wash to pass, while in the motion from left to
right the apertures are closed and the valves push the mass to be
evaporated before them.

From any motor whatever, the frame, E, receives a double to and fro
motion in a horizontal and vertical direction, the latter of which is
produced by the rods, f, which are provided at their lower, forked
extremity with rollers, e, over which passes the piece, d, that supports
the frame, E. At their upper pa