leaf was next put into a mixed solution of the above strengths of the
nitrate of calcium and phosphate of ammonia, and it became closely
inflected in between 5 m. and 10 m. Half-minims of a solution of one
part of the nitrate of calcium to 218 of water were dropped on the
discs of three leaves, but produced no effect.
Magnesium, Acetate, Nitrate, and Chloride of. Four leaves were immersed
in 120 minims of solutions, of one part to 437 of water, of each of
these three salts; after 6 hrs. there was no inflection; but after 22
hrs. one of the leaves in the acetate was rather more inflected than
generally occurs from an immersion for this length of time in water.
Some of the solution (1 gr. to 20 oz.) of phosphate of ammonia was then
added to the three solutions. The leaves in the acetate mixed with the
phosphate underwent some inflection; and this was well pronounced after
24 hrs. Those in the mixed nitrate were decidedly inflected in 4 hrs.
30 m., but the degree of inflection did not afterwards much increase;
whereas the four leaves in the mixed chloride were greatly inflected in
a few minutes, and after 4 hrs. had almost every tentacle closely
inflected. We thus see that the acetate and nitrate of magnesium injure
the leaves, or at least prevent the subsequent action of phosphate of
ammonia; whereas the chloride has no such tendency. [page 183]
Magnesium, Sulphate of. Half-minims of a solution of one part to 218 of
water were placed on the discs of ten leaves, and produced no effect.
Barium, Acetate of. Four leaves were immersed in 120 minims of a
solution of one part to 437 of water, and after 22 hrs. there was no
inflection, but the glands were blackened. The leaves were then placed
in a solution (1 gr. to 20 oz.) of phosphate of ammonia, which caused
after 26 hrs. only a little inflection in two of the leaves.
Barium, Nitrate of. Four leaves were immersed in 120 minims of a
solution of one part to 437 of water; and after 22 hrs. there was no
more than that slight degree of inflection, which often follows from an
immersion of this length in pure water. I then added some of the same
solution of phosphate of ammonia, and after 30 m. one leaf was greatly
inflected, two others moderately, and the fourth not at all. The leaves
remained in this state for 24 hrs.
Strontium, Acetate of. Four leaves, immersed in 120 minims of a
164