Succinic Acid.—Three leaves were immersed in ninety minims of a solution of 1 gr. to 437 of water; after 4 hrs. 15 m. considerable and after 23 hrs. great inflection; many of the glands pale; fluid coloured pink. The leaves were then washed and placed in water; after two days there was some re-expansion, but many of the glands were still white. This acid is not nearly so poisonous as oxalic or benzoic. Uric Acid.—Three leaves were immersed in 180 minims of a solution of 1 gr. to 875 of warm water, but all the acid was not dissolved; so that each received nearly 1/16 of a grain. After 25 m. there was some slight inflection, but this never increased; after 9 hrs. the glands were not discoloured, nor was the solution coloured pink; nevertheless much mucus was secreted. The leaves were then placed in water, and by next morning fully re-expanded. I doubt whether this acid really causes inflection, for the slight movement which at first occurred may have been due to the presence of a trace of albuminous matter. But it produces some effect, as shown by the secretion of so much mucus. Hippuric Acid.—Four leaves were immersed in 120 minims of a solution of 1 gr. to 437 of water. After 2 hrs. the fluid was coloured pink; glands pale, but no inflection. After 6 hrs. some inflection; after 9 hrs. all four leaves greatly inflected; much mucus secreted; all the glands very pale. The leaves were then left in water for two days; they remained closely inflected, with their glands colourless, and I do not doubt were killed. Hydrocyanic Acid.—Four leaves were immersed, each in thirty minims of one part to 437 of water; in 2 hrs. 45 m. all the tentacles were considerably inflected, with many of the glands pale; after 3 hrs. 45 m. all strongly inflected, and the surrounding fluid coloured pink; after 6 hrs. all closely inflected. After [page 196] an immersion of 8 hrs. 20 m. the leaves were washed and placed in water; next morning, after about 16 hrs., they were still inflected and discoloured; on the succeeding day they were evidently dead. Two leaves were immersed in a stronger mixture, of one part to fifty of water; in 1 hr. 15 m. the glands became as white as porcelain, as if they had been dipped in boiling water; very few of the tentacles were inflected; but after 4 hrs. almost all were inflected. These leaves were then placed in water, and next morning were evidently dead. Half-minim drops of the same strength (viz. one part to fifty of water) were next placed on the discs of five leaves; after 21 hrs. all the outer tentacles were inflected, and the leaves appeared much injured. I likewise touched the secretion round a large number of glands with minute drops (about 1/20 of a minim, or .00296 ml.) of Scheele’s mixture (6 per cent.); the glands first became bright red, and after 3 hrs. 15 m. about two-thirds of the tentacles bearing these glands were inflected, and remained so for the two succeeding days, when they appeared dead.]