Cuar. IX.] CAMPHOR. 171 
occasion, however, after a lonzer immersion of 24 hrs., there was well- 
marked aggregation. A solution made by adding two drops of campho- 
rated spirits to an ounce of water did not act on one leaf; whereas 
thirty minims added to an ounce of water acted on two leaves immersed 
together. 
g Length of 
3 Length of Time between 
3 ; the Immersion 
‘g _|!mmersion in) Length of Time between the Act of Brushing | of the Leaves 
8 the Solution and the Inflection of the Tentacles. peg tee a 
@ =| of Camphor. Sign of the 
5 Inflection of the 
Tentacles. 
1 i5m j3.m. considerable inflection; 4 m. all ee 
eerie { the tentacles except 3 or 4 inflected. ‘ 
2 |5m, 6 m. first sign of inflection. 11 m. 
6 m. 30 s. slight. inflection; 7 m. 30 i 
134 ? 2 
2 || O38 { plain inflection. of HL eY Se 
4 4m.30s 2m. 30 s.a trace of inflection; 3 m.), - = 
peed plain; 4m. strongly marked. 5 oe 
Ada 2m. 30 s. a trace of inflection; 3 m.|' 6 m. 30s 
i plain inflection. } sees 
2m. 30s. decided inflection; 3 m. 30s. Py 
ya { strongly marked. } eae) 
2 m. 30s. slight inflection ; 3 m. plain ;); 
7 4m. { 4m. well marked. f 6m. 30 s. 
8 | 3m 2m, trace of inflection; 3 m. consider-\'  _ - 
os \{_ able, 6 m, strong inflection. 3 
9 |3m 2m. trace of inflection; 3 m. consider-\) , - 
| meaue able, 6 m. strong inflection. . 
M. Vogel has shown* that the flowers of various plants do not 
wither so soon when their stems are placed in a solution of camphor 
as when in water; and that if already slightly withered, they recover 
more quickly. The germination of certain seeds is also accelerated by 
the solution. So that camphor acts 4s a stimulant, and it is the only 
known stimulant for plants, I wished, therefore, to ascertain whether 
camphor would render the leaves of Drosera more seusitive to 
mechanical irritation than they naturally are. Six leaves were left in 
distilled water for 5 m. or 6 m., and then gently brushed twice or 
thrice, whilst still under water, with a soft camel-hair brush; but no 
movement ensued. Nine leaves, which had been immersed in the 
above solution of camphor for the times stated in the above table, 
* ¢Gardener’s Chronicle,’ 1874, p. 671. Nearly similar observations were 
made in 1798 by B. S. Barton. 
