mg.
Four leaves were immersed as before in a solution of one part to
656,250 of water (1 gr. to 1500 oz.); but on this occasion I happened
to select leaves which were very little sensitive, as on other
occasions I chanced to select unusually sensitive leaves. The leaves
were not more affected after 12 hrs. than [page 163] the four
corresponding ones in water; but after 24 hrs. they were slightly more
inflected. Such evidence, however, is not at all trustworthy.
Twelve leaves were immersed, each in thirty minims of a solution of one
part to 1,312,500 of water (1 gr. to 3000 oz.); so that each leaf
received 1/48000 of a grain (.00135 mg.). The leaves were not in very
good condition; four of them were too old and of a dark red colour;
four were too pale, yet one of these latter acted well; the four
others, as far as could be told by the eye, seemed in excellent
condition. The result was as follows:
(1) This was a pale leaf; after 40 m. about thirty-eight tentacles
inflected; after 3 hrs. 30 m. the blade and many of the outer tentacles
inflected; after 10 hrs. 15 m. all the tentacles but seventeen
inflected, and the blade quite doubled up; after 24 hrs. all the
tentacles but ten more or less inflected. Most of them were closely
inflected, but twenty-five were only sub-inflected.
(2) After 1 hr. 40 m. twenty-five tentacles inflected; after 6 hrs. all
but twenty-one inflected; after 10 hrs. all but sixteen more or less
inflected; after 24 hrs. re-expanded.
(3) After 1 hr. 40 m. thirty-five inflected; after 6 hrs. a large
number (to quote my own memorandum) inflected, but from want of time
they were not counted; after 24 hrs. re-expanded.
(4) After 1 hr. 40 m. about thirty inflected; after 6 hrs. a large
number all round the leaf inflected, but they were not counted; after
10 hrs. began to re-expand.
(5) to (12) These were not more inflected than leaves often are in
water, having respectively 16, 8, 10, 8, 4, 9, 14, and 0 tentacles
inflected. Two of these leaves, however, were remarkable from having
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