with this power, for we have seen that the fluids in which they were
immersed often became pink, and the glands pale-coloured or white. Many
of the poisonous acids, such as hydriodic, benzoic, hippuric, and
carbolic (but I neglected to record all the cases), caused the
secretion of an extraordinary amount of mucus, so that long ropes of
this matter hung from the leaves when they were lifted out of the
solutions. Other acids, such as hydrochloric and malic, have no such
ten-
* Miller s Elements of Chemistry, part i. 1867, p. 87. [page 198]
dency; in these two latter cases the surrounding fluid was not coloured
pink, and the leaves were not poisoned. On the other hand, propionic
acid, which is poisonous, does not cause much mucus to be secreted, yet
the surrounding fluid became slightly pink. Lastly, as in the case of
saline solutions, leaves, after being immersed in certain acids, were
soon acted on by phosphate of ammonia; on the other hand, they were not
thus affected after immersion in certain other acids. To this subject,
however, I shall have to recur. [page 199]
CHAPTER IX.
THE EFFECTS OF CERTAIN ALKALOID POISONS, OTHER SUBSTANCES AND VAPOURS.
Strychnine, salts of Quinine, sulphate of, does not soon arrest the
movement of the protoplasm Other salts of
quinine Digitaline Nicotine Atropine Veratrine Colchicine
Theine Curare Morphia Hyoscyamus Poison of the cobra, apparently
accelerates the movements of the protoplasm Camphor, a powerful
stimulant, its vapour narcotic Certain essential oils excite
movement Glycerine Water and certain solutions retard or prevent the
subsequent action of phosphate of ammonia Alcohol innocuous, its vapour
narcotic and poisonous Chloroform, sulphuric and nitric ether, their
stimulant, poisonous, and narcotic power Carbonic acid narcotic, not
quickly poisonous Concluding remarks.
179