Section 56
56. A Cupping-Glass, to which is attached, an Air-exhausted
Compartment.
THE construction of a cupping-glass which shall attract without the aid
of fire. Let A B C (fig. 56), be a cupping-glass, such as is usually
applied to the body,having a partition across it, D E : through the
bottom of the cupping-glass let two sliding tubes be inserted, F G being
the outer tube and H K the inner; and in these, but outside the
cupping-glass, pierce corresponding holes, L and M. Let the inner
extremities of both the tubes be open, but the outer extremity of H K be
closed and provided with a handle. Under the partition D E place
another pair of sliding tubes, N X, like those just described; but the
corresponding holes must be within the cupping-glass, and be precisely
adapted to a hole in the partition. When these perforations are
complete, let the handles of the sliding tubes be turned round,
so that the holes in the lower tubes may be in a line, while those under
the partition, not being allowed to coincide, remain closed. Now, the
chamber D C being full of air, by applying the orifice L M to the mouth
we can suck out a portion of that air; and then, by turning the handle
again and not removing the tubes from the mouth, we can keep the air
in the vessel C D rarefied; and this must be repeated until we have
drawn off a large quantity of air. Then, applying the glass to the flesh
in the usual manner, we open the holes in the sliding tubes N X by means
of the handle; and it must follow that some of the air in the vessel A D
E will pass into the place of the air withdrawn from C D, while into the
void thus created both the flesh and the matter about it will be drawn
up through the interstices of the flesh which we call invisible spaces
or pores.
Section 57.
Index.