Oil of Cloves.—­A mixture was made in the same manner as in the last case, and three leaves were immersed in it.  After 30 m. there was only a trace of inflection which never increased.  After 1 hr. 30 m. the glands were pale, and after 6 hrs. white.  No doubt the leaves were much injured or killed.

Turpentine.—­Small drops placed on the discs of some leaves killed them, as did likewise drops of creosote.  A plant was left for 15 m. under a 12-oz. vessel, with its inner surface wetted with twelve drops of turpentine; but no movement of the tentacles ensued.  After 24 hrs. the plant was dead.

Glycerine.—­Half-minims were placed on the discs of three leaves:  in 2 hrs. some of the outer tentacles were irregularly inflected; and in 19 hrs. the leaves were flaccid and apparently dead; the glands which had touched the glycerine were colourless.  Minute drops (about 1/20 of a minim) were applied to the glands of several tentacles, and in a few minutes these moved and soon reached the centre.  Similar drops of a mixture of four dropped drops to 1 oz. of water were likewise applied to several glands; but only a few of the tentacles moved, and these very slowly and slightly.  Half-minims of this same mixture placed on the discs of some leaves caused, to my surprise, no inflection in the course of 48 hrs.  Bits of meat were then given them, and next day they were well inflected; notwithstanding that some of the discal glands had been rendered almost colourless.  Two leaves were immersed in the same mixture, but only for 4 hrs.; they were not inflected, and on being afterwards left for 2 hrs. 30 m. in a solution (1 gr. to 1 oz.) of carbonate of ammonia, their glands were blackened, their tentacles inflected, and the protoplasm within their cells aggregated.  It appears [page 213] from these facts that a mixture of four drops of glycerine to an ounce of water is not poisonous, and excites very little inflection; but that pure glycerine is poisonous, and if applied in very minute quantities to the glands of the outer tentacles causes their inflection.

The Effects of Immersion in Water and in various Solutions on the subsequent Action of Phosphate and Carbonate of Ammonia.—­We have seen in the third and seventh chapters that immersion in distilled water causes after a time some degree of aggregation of the protoplasm, and a moderate amount of inflection, especially in the case of plants which have been kept at a rather high temperature.  Water does not excite a copious secretion of mucus.  We have here to consider the effects of immersion in various fluids on the subsequent action of salts of ammonia and other stimulants.  Four leaves which had been left for 24 hrs. in water were given bits of meat, but did not clasp them.  Ten leaves, after a similar immersion, were left for 24 hrs. in a powerful solution (1 gr. to 20 oz.) of phosphate of ammonia, and only one showed even a trace of inflection.  Three of these leaves, on being