Oar. [X. ESSENTIAL OILS, ETC. 211 
elapsed, and two not until a few minutes later. On the other 
hand, it will be seen in the right-hand column of the table that 
most of the leaves subjected to the solution, and which were 
brushed,. became inflected in a much shorter time. The move- 
ment of the tentacles of some of these leaves was so rapid that 
it could be plainly seen through a very weak lens. | 
Two or three other experiments are worth giving. A large 
old leaf, after being immersed for 10 m. in the solution, did not 
appear likely to be soon inflected ; so I brushed it, and in 2 m, 
it began to move, and in 3 m. was completely shut. Another 
leaf, after an immersion of 15 m., showed no signs of inflection, 
so was brushed, and in 4 m. was grandly inflected. A third leaf, 
after an immersion of 17 m., likewise showed no signs of in- 
flection; it was then brushed, but did not move for 1 hr.; so 
that here was a failure. It was again brushed, and now in 
9 m. a few tentacles became inflected; the failure therefore was 
not complete. 
We may conclude that a small dose of camphor in solution is a 
powerful stimulant to Drosera. It not only soon excites the ten- 
tacles to bend, but apparently renders the glands sensitive to a 
touch, which by itself does not cause any movement. Or itmay 
be that a slight mechanical irritation not enough to cause any 
inflection yet gives some tendency to movement, and thus 
reinforces the action of the camphor. This latter view would 
have appeared to me the more probable one, had it not been 
shown by M. Vogel that camphor is a stimulant in other ways to 
various plants and seeds. 
Two plants bearing four or five leaves, and with their roots 
in a little cup of water, were exposed to the vapour of some 
bits of camphor (about as large as a filbert-nut), under a 
vessel holding ten fluid ounces. After 10 hrs. no inflection 
ensued ; but the glands appeared to be secreting more copiously. 
The leaves were in a narcotised condition, for on bits of meat 
being placed on two of them, there was no inflection in 3 hrs, 
15 m., and even after 13 hrs. 15 m. only a few of the outer 
tentacles were slightly inflected; but this degree of movement 
shows that the leaves had not been killed by an exposure 
during 10 hrs. to the vapour of camphor. 
Oil of Caruway.— Water is said to dissolve about a thousandth 
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 waa 
sore inflection, which became moderately pronounced in two ot 
