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. Mercury, Perchloride of.—Three leaves were immersed in ninety minims of a solution of one part to 437 of water; after 22 m. there was some slight inflection, which in 48 m. became well pronounced; the glands were now blackened. After 5 hrs. 35 m. all the tentacles closely inflected; after 24 hrs. still [page 184] inflected and discoloured. The leaves were then removed and left for two days in water; but they never re-expanded, being evidently dead. Zinc, Chloride of.—Three leaves immersed in ninety minims of a solution of one part to 437 of water were not affected in 25 hrs. 30 m. Aluminium, Chloride of.—Four leaves were immersed in 120 minims of a solution of one part to 437 of water; after 7 hrs. 45 m. no inflection; after 24 hrs. one leaf rather closely, the second moderately, the third and fourth hardly at all, inflected. The evidence is doubtful, but I think some power in slowly causing inflection must be attributed to this salt. These leaves were then placed in the solution (1 gr. to 20 oz.) of phosphate of ammonia, and after 7 hrs. 30 m. the three, which had been but little affected by the chloride, became rather closely inflected.