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.

Aluminium, Nitrate of.—­Four leaves were immersed in 120 minims of a solution of one part to 437 of water; after 7 hrs. 45 m. there was only a trace of inflection; after 24 hrs. one leaf was moderately inflected.  The evidence is here again doubtful, as in the case of the chloride of aluminium.  The leaves were then transferred to the same solution, as before, of phosphate of ammonia; this produced hardly any effect in 7 hrs. 30 m.; but after 25 hrs. one leaf was pretty closely inflected, the three others very slightly, perhaps not more so than from water.

Aluminium and Potassium, Sulphate of (common alum).—­Half-minims of a solution of the usual strength were placed on the discs of nine leaves, but produced no effect.

Gold, Chloride of.—­Seven leaves were immersed in so much of a solution of one part to 437 of water that each received 30 minims, containing 1/16 of a grain, or 4.048 mg., of the chloride.  There was some inflection in 8 m., which became extreme in 45 m.  In 3 hrs. the surrounding fluid was coloured purple, and the glands were blackened.  After 6 hrs. the leaves were transferred to water; next morning they were found discoloured and evidently killed.  The secretion decomposes the chloride very readily; the glands themselves becoming coated with the thinnest layer of metallic gold, and particles float about on the surface of the surrounding fluid.

Lead, Chloride of.—­Three leaves were immersed in ninety minims of a solution of one part to 437 of water.  After 23 hrs. there was not a trace of inflection; the glands were not blackened, and the leaves did not appear injured.  They were then trans- [page 185] ferred to the solution (1 gr. to 20 oz.) of phosphate of ammonia, and after 24 hrs. two of them were somewhat, the third very little, inflected; and they thus remained for another 24 hrs.