Half-minims of the solution were placed on the discs of six leaves;
after 23 hrs. one had all its tentacles, two had a few, and the others
none inflected; so that the discal glands, when irritated by this salt,
do not transmit any strong motor impulse to the outer tentacles. After
48 hrs. the glands on the discs of all six leaves were evidently much
injured or quite killed. It is clear that this salt is highly
poisonous.*
Acetate of Quinine. Four leaves were immersed, each in thirty minims of
a solution of one part to 437 of water. The solution was tested with
litmus paper, and was not acid. After only 10 m. all four leaves were
greatly, and after 6 hrs. immensely, inflected. They were then left in
water for 60 hrs., but never re-expanded; the glands were white, and
the leaves evidently dead. This salt is far more efficient than the
sulphate in causing inflection, and, like that salt, is highly
poisonous.
Nitrate of Quinine. Four leaves were immersed, each in thirty minims of
a solution of one part to 437 of water. After 6 hrs. there was hardly a
trace of inflection; after 22 hrs. three of the leaves were moderately,
and the fourth slightly inflected; so that this salt induces, though
rather slowly, well-marked inflection. These leaves, on being left in
water for 48 hrs., almost
*Binz found several years ago (as stated in The Journal of Anatomy and
Phys. November 1872, p. 195) that quinia is an energetic poison to low
vegetable and animal organisms. Even one part added to 4000 parts of
blood arrests the movements of the white corpuscles, which become
rounded and granular. In the tentacles of Drosera the aggregated
masses of protoplasm, which appeared killed by the quinine, likewise
presented a granular appearance. A similar appearance is caused by very
hot water. [page 203]
completely re-expanded, but the glands were much discoloured. Hence
this salt is not poisonous in any high degree. The different action of
the three foregoing salts of quinine is singular.
Digitaline. Half-minims of a solution of one part to 437 of water were
placed on the discs of five leaves. In 3 hrs. 45 m. Some of them had
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