one part of the nitrate to 8750 of water (1 gr. to 20 oz.), so that
each received 1/320 of a grain (.2025 mg.). Before 30 m. had elapsed,
four of these leaves were immensely, and two of them moderately,
inflected. The glands were rendered of a dark red. The four
corresponding leaves in water were not at all affected until 6 hrs. had
elapsed, and then only the short tentacles on the borders of the disc;
and their inflection, as previously explained, is never of any
significance.
Four leaves were immersed, each in thirty minims of a solution of one
part to 17,500 of water (1 gr. to 40 oz.), so that each received 1/640
of a grain (.101 mg.); and in less than 45 m. three of them had all
their tentacles, except from four to ten, inflected; the blade of one
being inflected after 6 hrs., and the blade of a second after 21 hrs.
The fourth leaf was not at all affected. The glands of none were
darkened. Of the corresponding leaves [page 152] in water, only one had
any of its exterior tentacles, namely five, inflected; after 6 hrs. in
one case, and after 21 hrs. in two other cases, the short tentacles on
the borders of the disc formed a ring, in the usual manner.
Four leaves were immersed, each in thirty minims of a solution of one
part to 43,750 of water (1 gr. to 100 oz.), so that each leaf got
1/1600 of a grain (.0405 mg.). Of these, one was much inflected in 8
m., and after 2 hrs. 7 m. had all the tentacles, except thirteen,
inflected. The second leaf, after 10 m., had all except three
inflected. The third and fourth were hardly at all affected, scarcely
more than the corresponding leaves in water. Of the latter, only one
was affected, this having two tentacles inflected, with those on the
outer parts of the disc forming a ring in the usual manner. In the leaf
which had all its tentacles except three inflected in 10 m., each gland
(assuming that the leaf bore 160 tentacles) could have absorbed only
1/251200 of a grain, or .000258 mg.
Four leaves were separately immersed as before in a solution of one
part to 131,250 of water (1 gr. to 300 oz.), so that each received
1/4800 of a grain, or .0135 mg. After 50 m. one leaf had all its
tentacles except sixteen, and after 8 hrs. 20 m. all but fourteen,
inflected. The second leaf, after 40 m., had all but twenty inflected;
and after 8 hrs. 10 m. began to re-expand. The third, in 3 hrs. had
about half its tentacles inflected, which began to re-expand after 8
133