It may be worth adding that immersion in cold
* As the opacity and porcelain-like appearance of the glands is
probably due to the coagulation of the albumen, I may add, on the
authority of Dr. Burdon Sanderson, that albumen coagulates at about
155o, but, in presence of acids, the temperature of coagulation is
lower. The leaves of Drosera contain an acid, and perhaps a difference
in the amount contained may account for the slight differences in the
results above recorded.
** It appears that cold-blooded animals are, as might have been
expected, far more sensitive to an increase of temperature than is
Drosera. Thus, as I hear from Dr. Burdon Sanderson, a frog begins to be
distressed in water at a temperature of only 85 Fahr. At 95 the
muscles become rigid, and the animal dies in a stiffened condition.
[page 75]
water does not cause any inflection: I suddenly placed four leaves,
taken from plants which had been kept for several days at a high
temperature, generally about 75 Fahr. (23 .8 Cent.), in water at 45
(7 .2 Cent.), but they were hardly at all affected; not so much as some
other leaves from the same plants, which were at the same time immersed
in water at 75 ; for these became in a slight degree inflected. [page
76]
CHAPTER V.
THE EFFECTS OF NON-NITROGENOUS AND NITROGENOUS ORGANIC FLUIDS ON THE
LEAVES.
Non-nitrogenous fluids Solutions of gum arabic Sugar Starch Diluted
alcohol Olive oil Infusion and decoction of tea Nitrogenous
fluids Milk Urine Liquid albumen Infusion of raw meat Impure
mucus Saliva Solution of isinglass Difference in the action of these
two sets of fluids Decoction of green peas Decoction and infusion of
66