Cuap. IX, EFFECTS OF PREVIOUS IMMERSION, 213 
from these facts that a mixture of four drops of glycerine to 
an ounce of water is not poisonous, and excites very little in- 
flection; but that pure glycerine is poisonous, and if applied 
in very minute quantities to the glands of the outer tentacles 
causes their inflection. 
The Effects of Immersion in Water and in various Solutions on 
the subsequent Action of Phosphate and Carbonate of Ammonia.— 
We have seen in the third and seventh chapters that immersion 
in distilled water causes after a time some degree of aggregation 
of the protoplasm, and a moderate amount of inflection, espe- 
cially in the case of plants which have been kept at a rather 
high temperature. Water does not excite a copious secretion 
of mucus. We have here to consider the effects of immersion 
in various fluids on the subsequent action of salts of ammonia 
and other stimulants. Four leaves which had been left for 
24 hrs. in water were given bits of meat, but did not clasp them. 
Ten leaves, after a similar immersion, were left for 24 hrs. in 
a powerful solution (1 gr. to 20 oz.) of phosphate of ammonia, 
and only one showed even a trace of inflection. Three of 
these leaves, on being left for an additional day in the solution, 
still remained quite unaffected. When, however, some of these 
leaves, which had been first immersed in water for 24 hrs., and 
then in the phosphate for 24 hrs. were placed in a solution of 
carbonate of ammonia (one part to 218 of water), the pro- 
toplasm in the cells of the tentacles became in a few hours 
strongly aggregated, showing that this salt had been absorbed 
and taken effect. i 
A short immersion in water for 20 m. did not retard the sub- 
sequent action of the phosphate, or of splinters of glass placed 
on the glands; but in two instances an immersion for 50 m. pre- 
vented any effect from a solution of camphor. Several leaves 
which had been left for 20 m. in a solution of one part of white 
sugar to 218 of water were placed in the phosphate solution, 
the action of which was delayed; whereas a mixed solution of 
sugar and the phosphate did not in the least interfere with the 
effects of the latter. Three leaves, after being immersed for 20 m. 
in the sugar solution, were placed in a solution of carbonate of 
ammonia (one. part to 218 of water); in 2 m. or 3 m. the glands 
were blackened, and after 7 m. the tentacles were considerably 
inflected, so that the solution of sugar, though it delayed the 
action of the phosphate, did not delay that of the carbonate. 
Immersion in a similar solution of gum arabic for 20 m. had no 
retarding action on the phosphate. Three leaves were left for 
20 m. in a mixture of one part of alcohol to seven parts of water 
