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Show 202 DROSERA ROTUNDIFOLIA. CHAP. IX. bad become aggregated into reticulated dingy-coloured masses, having rounded and angular interspaces. As I ha~e never seen this effect produced by the carbonate of ammoma alone, it must be attributed to the previous action of the quinine. These reticulated masses were watched for some time, but did not change their forms; so that the protoplasm no doubt bad been killed by the combined action of the two salts, though exposed to them for only a short time. Another leaf after an immersion for 24 hrs. in the qumme solution, becar~e somewhat flaccid, and the protoplasm in all the cells was aggregated. Many of the aggregated masses were discoloured, and presented a granular appearance; . they were spherical, or elongated, or still more commonly consisted of little curved chains of small globules. None of these masses exhibited the least movement, and no doubt were all dead. Half-minims of the solution were placed on the discs of six leaves; after 23 brs. one bad all its tentacles, two had a few, and the others none inflected; so that the discal glands, when irritated by this salt, do not transmit any strong motor impulse to the outer tentacles. After 48 hrs. the glands on the discs of all six leaves were evidently much injured or quite killed. It is clear that this salt is highly poisonous.* Acttate of Quinine.- Four leaves were immersed, each in thirty minims of a solution of one part to 437 of water. The solution was tested with litmus paper, and was not acid. After only 10 m. all four leaves were greatly, and after 6 brs. immensely, inflected. They were then left in water for 60 hrs., but never re-expanded; the glands were white, and the leaves evidently dead. This salt is far more efficient than the sulphate in causing inflection, and, like that salt, is highly poisonous. Nitrate of Quinine.-Four leaves were immersed, each in thirty minims of a solution of one part to 437 of water. After 6 hrs. there was hardly a trace of inflection ; after 22 hrs. three of the leaves were moderately, and the fourth slightly inflected; so that this salt induces, though rather slowly, well-marked inflection. These leaves, on being left in water for 48 hrs., almost * Binz found several years ago (as stated in 'The Journal of Anatomy and Phys.' November 1872, p. 1 95) that quinia is an energetic poison to low vegetable and animal organisms. Even one part added to 4000 parts of blood arrests the movements of the white corpuscles, which become "rounded and granular." In the tentacles of Drosera the aggregated masses of protoplasm, which appeared killed by the quinine, likewise presented a granular appearance. A similar appearance is caused by very hot water. CHAP. IX. ALKALOID POISONS. 203 completely re-expancled, but the glands were much liscolourcd. ~ence this ~alt is not poisonous in any high degree. The different actwn of the three foregoing salts of quinine is singular. Diyitaline.-Half-minims of a solution of one part to 437 of water .were placed on the discs of five leaves. In 3 hrs. 45 m. some of them had their tentacles, and one had its blade, moderately inflected. After 8 hrs. three of them were well inflected; the fourth had only a few tentacles inflected, and the fifth (an old leaf) was not at all affected. They remained in nearly the Rame state for two days, but the glands on their discs became pale. On the third clay the leaves appeared much injured. Nevertheless, when bits of meat were placed on two of them, the outer tentacles became inflected. A minute drop (about -lo of a minim) of the solution was applied to three glands, and after 6 hrs. all three tentacles were inflected, but next day had nearly re-expanded; so that this very small dose of '2R~oo of a grain ('00225 mg.) acts on a tentacle, but is not poisonous. 1 t appears from these several facts that digitaline causes inflection, and poisons the glands which absorb a moderately large amount. Nicotine.-The secretion round several glands was touched with a minute drop of the pure fluid, and the glands were instantly blackened; the tentacles becoming inflected in a few minutes. Two leaves were immersed in a weak solution of two drops to 1 oz., or 437 grains, of water. When examined after 3 hrs. 20 m., only twenty-one tentacles on one leaf were closely inflected, and six on the other slightly so ; but all the glands were blackened, or very dark-coloured, with the protoplasm in all the cells of all the tentacles much aggregated and dark-coloured. The leaves were not quite killed, for on being placed in a little solution of carbonate of ammonia (2 grs. to 1 oz.) a few more tentacles became inflected, the remainder not being acted on during the next 24 hrs. Half-minims of a stronger solution .(two drops to ! oz. of water) were placed on the discs of six leaves, and in 30m. all those tentacles became inflected; the glands of which had actually touched the solution, as shown by their blackness; but hardly any motor influence was transmitted to the outer tentacles. After 22 hrs. most of the glands on the discs appeared dead; but this could not have been the case, as when bits of meat were placed on three of them, some few of the outer tentacles were inflected in 24 hrs. Hence nicotine has a great tendency to blacken the glands and to induce aggTegation |