Cuar. IX.) ESSENTIAL OILS, ETC. 173 
part of its weight of this oil. A drop was added to an ounce of water 
and the bottle occasionally shaken during a day; but many minute 
globules remained undissolved. Five leaves were immersed in this 
mixture; in from 4 m. to 5 m. there was some inflection, which 
became moderately pronounced in two or three additional minutes. 
After 14 m. all five leaves were well, and some of them closely, 
inflected. After 6 hrs. the glands were white, and much mucus had 
been secreted. The leaves were now flaccid, of a peculiar dull-red 
colour, avd evidently dead. One of the leaves, after an immersion of 
4 m. was brushed, like the leaves in the camphor, but this produced 
no effect. A plant with its roots in water was exposed under a 10-o0z. 
vessel to the vapour of this oil, and in 1 hr. 20 m. one leaf showed a 
trace of inflection. After 5 hrs. 20 m. the cover was taken off and 
the leaves examined; one had all its tentacles closely inflected, the 
second about half in the same state; and the third all sub-inflected. 
The plant was left in the open air for 42 hrs., but not a single tentacle 
expanded ; all the glands appeared dead, except here and there one, 
which was still secreting. It is evident that this oil is highly exciting 
and poisonous to Drosera. 
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 celourless. Minute drops (about 4; 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 0%.) 
of carbonate of ammonia, their glands were blackened, their tentacles 
inflected and the protoplasm within their cells aggregated. It appears 
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 
