lve
the steel used. A residue was obtained as before. With solution 1, the
residue contained, C, 1.021; sol. 2, C, 0.969; sol. 3, C 1.049 the
atomic ratio of iron to carbon was Fe 2.694: C, 1; Fe, 2.65: C, 1; Fe),
2.867 C, 1): sol. 4. C, 0.266 per 100 of steel. The authors conclude
that the carbon in cold rolled steel exists not simply diffused
mechanically through the mass of steel but in the form of an iron
carbide, Fe_{3}C, a definite product, capable of resisting the action of
an oxidizing solution (if the latter is not too strong), which exerts a
rapid solvent action upon the iron through which the carbide is
distributed.

* * * * *

APPARATUS FOR EXTRACTING STARCH FROM POTATOES.

In the apparatus of Mr. Angele, of Berlin, shown in the annexed cuts
(Figs. 1 and 2), the potatoes, after being cleaned in the washer, C,
slide through the chute, v, into a rasp, D, which reduces them to a fine
pulp under the action of a continuous current of water led in by the
pipe, d. The liquid pulp flows into the iron reservoir, B, from whence a
pump, P, forces it through the pipe, w, to a sieve, g, which is
suspended by four bars and has a backward and forward motion. By means
of a rose, c, water is sprinkled over the entire surface of the sieve
and separates the fecula from the fibrous matter. The water, charged
with fine particles of fecula, and forming a sort of milk, flows through
the tube, z, into the lower part, N, of the washing apparatus, F, while
the pulp runs over the sieve and falls into the grinding-mill, H. This
latter divides all those cellular portions of the fecula that have not
been opened by the rasp, and allows them to run, through the tube, h,
into the washing apparatus, F, where the fecula is completely separated
from woody fibers. The fluid pulp is carried by means of a helix, i, to
a revolving perforated drum at e. From this, the milky starch flows into
the jacket, N, while the pulp (ligneous fibers) makes its exit from the
apparatus through the aperture, n, and falls into the reservoir, o.

[Illustration: ANGELE'S POTATO-STARCH APPARATUS.]

The liquid from the jacket, N, passes to a refining sieve, K, which,
like the one before mentioned, has a backward and forward motion, and
which is covered with very fine silk gauze in order to separate the very
finest impurities from the milky starch. The refined liquid then flows
into the reservoir, m, and the impure mass of se