the bulb of the piece _a_
are now warmed together, the end of the tube only moderately and the
bulb to about its softening temperature. The tube _a_ is now inserted in
the open end of the large tube, and the bulb softened with a suitable
flame and pressed into good contact with the tube. It is then reheated,
including the joint, blown a little and pulled out to form a straight
tube in line with the main tube. By warming the joint a little, and
proper rotation, the capillary may be brought into the same straight
line with the rest of the tube.

Keeping this joint hot, a place about an inch from it on the tube _a_ is
warmed, and the piece of 1/4-inch tubing previously prepared is sealed
on at that point. The joint is then well annealed and allowed to cool.

The tube _a_ is now cut at such a place that when _b_ is inserted in the
open end the point will come near the end of the constriction of _a_, as
shown in _c_. Care is taken to get a clean square cut. The side tube is
now cut off about an inch from the main tube and corked. Tube _b_ is
sealed into the open end of _a_, in the same way as _a_ was sealed into
the large tube, and the joint carefully annealed.

=Discussion.=--As in the first method, the secret of success lies in
getting a square joint, and having the inner tube leave the outer one at
nearly right angles. All the remarks about annealing, lumps, etc., made
under the previous method apply here.

This method may be applied in sealing a small tube into the end of a
large one, the latter being either drawn to a cone and cut off at the
desired diameter, or else given a rounded end like a test-tube and a
hole the proper size blown in the center of it. A suitable thick-walled
bulb is to be blown on the small tube, as in the case described above.
This method is also used in making the Kjeldahl trap (_a_, Fig. 13), the
small tube to be inserted being first drawn, the thick bulb blown at its
point of union with the main tube, and then the small tube bent and cut.
The large bulb is best made with rather heavy wall, being either blown
in the middle of a tube, and one piece of the tube drawn or cut off, or
else made on the end of a tube. In the latter case a drop of glass must
be put on the point where the joint is to be, so as to get a hole of the
proper size with enough glass around it to prevent it from growing
larger when it is heated. The author prefers to blow the bulb in the
middle of the tube, draw off one end