Vapour of Sulphuric Ether.—­A plant was exposed for 30 m. to thirty minims of this ether in a vessel holding 19 oz.; and bits of raw meat were afterwards placed on many glands which had become pale-coloured; but none of the tentacles moved.  After 6 hrs. 30 m. the leaves appeared sickly, and the discal glands were almost dry.  By the next morning many of the tentacles were dead, as were all those on which meat had been placed; showing that matter had been absorbed from the meat which had increased the evil effects of the vapour.  After four days the plant itself died.  Another plant was exposed in the same vessel for 15 m. to forty minims.  One young, small, and tender leaf had all its tentacles inflected, and seemed much injured.  Bits of raw meat were placed on several glands on two other and older leaves.  These glands became dry after 6 hrs.; and seemed injured; the tentacles never moved, excepting one which was ultimately a little inflected.  The glands of the other tentacles continued to secrete, and appeared uninjured, but the whole plant after three days became very sickly. [page 220]

In the two foregoing experiments the doses were evidently too large and poisonous.  With weaker doses, the anaesthetic effect was variable, as in the case of chloroform.  A plant was exposed for 5 m. to ten drops under a 12-oz. vessel, and bits of meat were then placed on many glands.  None of the tentacles thus treated began to move in a decided manner until 40 m. had elapsed; but then some of them moved very quickly, so that two reached the centre after an additional interval of only 10 m.  In 2 hrs. 12 m. from the time when the meat was given, all the tentacles reached the centre.  Another plant, with two leaves, was exposed in the same vessel for 5 m. to a rather larger dose of ether, and bits of meat were placed on several glands.  In this case one tentacle on each leaf began to bend in 5 m.; and after 12 m. two tentacles on one leaf, and one on the second leaf, reached the centre.  In 30 m. after the meat had been given, all the tentacles, both those with and without meat, were closely inflected; so that the ether apparently had stimulated these leaves, causing all the tentacles to bend.

Vapour of Nitric Ether.—­This vapour seems more injurious than that of sulphuric ether.  A plant was exposed for 5 m. in a 12-oz. vessel to eight drops in a watch-glass, and I distinctly saw a few tentacles curling inwards before the glass was removed.  Immediately afterwards bits of meat were placed on three glands, but no movement ensued in the course of 18 m.  The same plant was placed again under the same vessel for 16 m. with ten drops of the ether.  None of the tentacles moved, and next morning those with the meat were still in the same position.  After 48 hrs. one leaf seemed healthy, but the others were much injured.