Potassium, Chloride of. Neither half-minims of a solution of one part
to 437 of water; left on the discs of six leaves for three days, nor
the immersion of three leaves during 25 hrs., in 30 minims of a
solution of one part to 875 of water, produced the least effect. The
immersed leaves were then treated with carbonate of ammonia, as
described under nitrate of potash, and with the same result.
Potassium, Iodide of. Half-minims of a solution of one part to 437 of
water were placed on the discs of seven leaves. In 30 m. one leaf had
the blade inflected; after some hours three leaves had most of their
submarginal tentacles moderately inflected; the remaining three being
very slightly affected. Hardly any of these leaves had their outer
tentacles inflected. After 21 hrs. all re-expanded, excepting two which
still had a few submarginal tentacles inflected. Three leaves were next
[page 181] immersed for 8 hrs. 40 m., each in 30 minims of a solution
of one part to 875 of water, and were not in the least affected. I do
not know what to conclude from this conflicting evidence; but it is
clear that the iodide of potassium does not generally produce any
marked effect.
Potassium, Bromide of. Half-minims of a solution of one part to 437 of
water were placed on the discs of six leaves; after 22 hrs. one had its
blade and many tentacles inflected, but I suspect that an insect might
have alighted on it and then escaped; the five other leaves were in no
way affected. I tested three of these leaves with bits of meat, and
after 24 hrs. they became splendidly inflected. Three leaves were also
immersed for 21 hrs. in 30 minims of a solution of one part to 875 of
water; but they were not at all affected, excepting that the glands
looked rather pale.
Lithium, Acetate of. Four leaves were immersed together in a vessel
containing 120 minims of a solution of one part to 437 of water; so
that each received, if the leaves absorbed equally, 1/16 of a grain.
After 24 hrs. there was no inflection. I then added, for the sake of
testing the leaves, some strong solution (viz. 1 gr. to 20 oz., or one
part to 8750 of water) of phosphate of ammonia, and all four became in
30 m. closely inflected.
Lithium, Nitrate of. Four leaves were immersed, as in the last case, in
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