ch the jelly nearly filled. The time at
which each glass was filled was noted, and exactly two hours were
allowed for the contents to cool in a current of air. The glass is
then set on a plate of glass, supported on a ring of a retort stand,
and the weight ascertained, which was necessary to force a metallic
disc, of ascertained size, through the jelly. The most convenient way
of doing this was by using a piece of apparatus of the form rudely
represented on the margin. The rectangular frame is of thin brass
wire, and the slightly cup-shaped disc, _d d_, is soldered to a wire,
attached to the upper short side of the rectangle. From the opposite
or lower side of the rectangle a small glass cup, _c._, is suspended,
into which weights are put as soon as the disc has been made to rest
on the surface of the jelly, _pp_ is the plate of glass on which the
test-glass is set. Whenever the disc tears the skin of the jelly and
begins to sink in it, no further addition, of weights is made, and
the weight of the disc, framework, and cup being known, we have an
estimate of the tenacity of the jelly. This process is but
approximative, and some practice is necessary before the operator
succeeds in getting uniform results from the same series of specimens.

+--------------------+
| | |
| | |
| | |
| d \_____/ d |
| |
| |
| |
| p--------------p |
| |
| |
+--------------------+
|
|
|
|
---------
c.

The following statement shows the results on such specimens as I could
procure. The disc was exactly 7/10ths of an inch in diameter.

TABLE NO. III.--TENACITY OF STARCH IN JELLIES.

No. Names of specimens. Weight in grains required
to break the jelly.
1. Tous les mois, C., C.L. 2,446*
2. Tous les mois, Grenada, Commercial 1,742
3. Maize, C., C.L. 955
4. Barbados yam, C., C.L. 895
5. Irish potato, from Belfast, C.L. 756
6. Tannia, C., C.L. 630
7. Bermuda arrowroot, finest Commercial