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 solution of one part to 437 of water, were not affected in 22 hrs.  They were then placed in some of the same solution of phosphate of ammonia, and in 25 m. two of them were greatly inflected; after 8 hrs. the third leaf was considerably inflected, and the fourth exhibited a trace of inflection.  They were in the same state next morning.

Strontium, Nitrate of.—­Five leaves were immersed in 120 minims of a solution of one part to 437 of water; after 22 hrs. there was some slight inflection, but not more than sometimes occurs with leaves in water.  They were then placed in the same solution of phosphate of ammonia; after 8 hrs. three of them were moderately inflected, as were all five after 24 hrs.; but not one was closely inflected.  It appears that the nitrate of strontium renders the leaves half torpid.

Cadmium, Chloride of.—­Three leaves were immersed in ninety minims of a solution of one part to 437 of water; after 5 hrs. 20 m. slight inflection occurred, which increased during the next three hours.  After 24 hrs. all three leaves had their tentacles well inflected, and remained so for an additional 24 hrs.; glands not discoloured.