Citrate of Ammonia.—Half-minims of a solution of one part to 437 of water were placed on the discs of six leaves. In 1 hr. the short outer tentacles round the discs were a little inflected, with the glands on the discs blackened. After 3 hrs. 25 m. one leaf had its blade inflected, but none of the exterior tentacles. All six leaves remained in nearly the same state during the day, the submarginal tentacles, however, [page 167] becoming more inflected. After 23 hrs. three of the leaves had their blades somewhat inflected; and the submarginal tentacles of all considerably inflected, but in none were the two, three, or four outer rows affected. I have rarely seen cases like this, except from the action of a decoction of grass. The glands on the discs of the above leaves, instead of being almost black, as after the first hour, were now after 23 hrs. very pale. I next tried on four leaves half-minims of a weaker solution, of one part to 1312 of water (1 gr. to 3 oz.); so that each received 1/2880 of a grain (.0225 mg.). After 2 hrs. 18 m. the glands on the disc were very dark-coloured; after 24 hrs. two of the leaves were slightly affected; the other two not at all. Acetate of Ammonia.—Half-minims of a solution of about one part to 109 of water were placed on the discs of two leaves, both of which were acted on in 5 hrs. 30 m., and after 23 hrs. had every single tentacle closely inflected. Oxalate of Ammonia.—Half-minims of a solution of one part to 218 of water were placed on two leaves, which, after 7 hrs., became moderately, and after 23 hrs. strongly, inflected. Two other leaves were tried with a weaker solution of one part to 437 of water; one was strongly inflected in 7 hrs.; the other not until 30 hrs. had elapsed. Tartrate of Ammonia.—Half-minims of a solution of one part to 437 of water were placed on the discs of five leaves. In 31 m. there was a trace of inflection in the exterior tentacles of some of the leaves, and this became more decided after 1 hr. with all the leaves; but the tentacles were never closely inflected. After 8 hrs. 30 m. they began to re-expand. Next morning, after 23 hrs., all were fully re-expanded, excepting one which was still slightly inflected. The shortness of the period of inflection in this and the following case is remarkable. Chloride of Ammonium.—Half-minims of a solution of one part to 437 of water were placed on the discs of six leaves. A decided degree of inflection in the outer and submarginal tentacles was perceptible in 25 m.; and this increased during the next three or four hours, but never became strongly marked. After only 8 hrs. 30 m. the tentacles began to re-expand, and by the next morning, after 24 hrs., were fully re-expanded on four of the leaves, but still slightly inflected on two.]