186 DROSERA ROTUNDIFOLIA. Cuap. VIIL 
of a. solution of one part to 437 of water; after 2 hrs. some inflec- 
tion; after 8 hrs. 45 m. tentacles closely inflected, with the 
glands blackened. After 22 hrs. still closely inflected, and the 
leaves flaccid. Placed in pure water, next day evidently dead. 
A rapid poison. 
Nick.l, Chloride of.—Three leaves immersed in ninety minims 
of a solution of one part to 437 of water; in 25 m. considerable 
inflection, and in 3 hrs. all the tentacles closely inflected. After 
22 hrs. still closely inflected; most of the glands, but not all, 
blackened. The leaves were then placed in water; after 24 hrs. 
remained inflected ; were somewhat discoloured, with the glands 
and tentacles dingy red. Probably killed. 
Cobalt, Chior:de of—Three leaves immersed in ninety minims 
of a solution of one part to 437 of water; after 23 hrs. there 
was not a trace of inflection, and the glands were not more 
blackened than often occurs after an equally long immersion in 
water. 
Platinum, Chloride of.—Three leaves immersed in ninety 
minims of a solution of one part to 487 of water; in 6 m. some 
inflection, which became immense after 48m. After 3 hrs. the 
glands were rather pale. After 24 hrs. all the tentacles still 
closely inflected; glands colourless; remained in same state for 
four days; leaves evidently killed. 
Concluding Remarks on the Action of the foregoing 
Salis—Of the fifty-one salts and metallic acids which 
were tried, twenty-five caused the tentacles to be in- 
flected, and twenty-six had no such effect, two rather 
doubtful cases occurring in each series. In the table 
at the head of this discussion, the salts are arranged 
according to their chemical affinities; but their action 
on Drosera does not seem to be thus governed. The 
nature of the base is far more important, as far as can 
be judged from the few experiments here given, than 
that of the acid; and this is the conclusion at which 
physiologists have arrived with respect to animals. 
We see this fact illustrated in all the nine salts of 
soda causing inflection, and in not being poisonous 
except when given in large doses; whereas seven of 
