By
removing the cork, c, from the tube the temperature of the water bath is
raised, while by pushing it in it is lowered. The apparatus never goes
wrong, and is very cheap. It was first made by Herr C. Braun, of Berlin.
[Illustration: FIG. 1.]
III.--TRITURATING APPARATUS.
The apparatus hereafter described is in general use, and was invented
by Herr Paul Grundner, of Berlin. It is particularly adapted for finely
dividing large quantities of emulsion. It consists essentially of a
wooden lid, a b, fitting upon a large stone pot, to the under side of
which two strong trapezoid pieces of wood, e d and e f, are fixed, in
the under part of which semicircular incisions are cut and held together
by two leather straps, supporting a strong, easily-removable iron
transverse bar, g h. Through the center of the lid, and turned by the
crank, m, passes the axle i, which ends under the lid in the long ring,
n.
The stiffened emulsion is then placed in the bag, o p q r, made of
fine but strong canvas, with meshes about 0.5 mm. (such as is used for
working upon with Berlin wool). The iron rod, g h, is then slipped
through the four loops at the bottom of the bag, the open end is slung
upon the ring, n, and bound tightly to it by the ribbons, r1. The loops
upon the iron bar are then pushed as close together in the middle as
possible, and the stone vessel is filled with water until o p q r is
completely covered.
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