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Show 204 DROSERA ROTUNDIFOLIA. CHAP. IX. of the protoplasm, but, except when pure, has very moderate power of inducing inflection, and still less power of causing a motor in:flnence to be transmitted from the discal glands to the outer tentacles. It is moderately poisonous. Atropine.-A grain was added to 437 grains of water, but was not all dissolved; another grain was added to 437 grains of a mixture of one part of alcohol to seven parts of water; and a third solution was made by adding one part of valerianate of a tropine to 437 of water. Half-minims of these three sol n tions were placed, in each case, on the discs of six leaves; but no effect whatever was produced, excepting that the glands on the discs to which the valerianate was given were shghtly discoloured. The six leaves on which drops of the solution of atropine in diluted alcohol had been left for 21 hrs. were given bits of meat, and all herame in 24 hrs. fairly welt in:flected; so that atropine does not exeite movement, and is not poisonous. I also tried in the same manner the alkaloid sold as dn,turine, which is believed not to differ from atropine, and it produced no effect. rrhroe of the leaves ·on which drops of this latter solution had been· left for 24 hrs. were likewise given bits of meat, and they had in the course of 24 hrs. a good many of their submarginal tentacles in:flected. VeTatrine, Colch·icine, Theine.-Solutions were mn,de of these three n,lkaloids by adding one part to 407 of wn,ter. Half-minims were placed, in each case, on the discs of at least six leaves, but no in:flection was caused, except perhaps a very slight amount by the theine. Half-minims of a strong infusion of ten, likewise produced, as formerly stn,ted, no effect. I also tried similar drops of an infusion of one part of the extract of colchieum, sold .by druggists, to 218 of water; and the leaves were observed for 48 hrs., without any effect being produced. The seven leaves on which drops of veratrine had been left for 26 hrs. were given bits of men,t, and after 21 hrs. were well in:flectod. These three alkaloids are therefore quite innocuous. C·urare.-One part of this famous poison was added to 218 of water, and three leaves were immersed in ninety minims of the filtered solution. In 3 hrs. 30 m. some of the tentacles were a little inflected; as was the blade of one, after 4 hrs. After 7 hrs. the glands were wonderfully bln,ckened, showing that matter of some kind had been absorbed. In 9 hrs. two of the leaves had most of their tentacles sub-in:flected, but the inflection did not increase in the course of 24 hrs. One of these leaves, after being immersed for 9 hrs. in the solution, was placed in water, and by next morning had largely re-expanded; CIIAP. IX. 205 the other two, after their immersion fm· 24 hrs., were likewise pbced in ":ater, and in 24 hrs. wore considerably ro-expanded, though thou glands were as black as ever. Half-minims were placed on the discs of six leaves, and no inflection ensued; but after three days tho gland on the discs appeared rath r dry, yet to my surprise were not blackened. On another occasion drops wore placed on the discs of six leaves, and a consi lCI·able amount of inflection was soon caused; but as I had not filtered the solution, floating particles may have acted on tho glands. After 24 hrs. bits of meat were placed on the discs of throe of these leaves, and next day they became strongly inflected. As I at fin~t thought that the poison might not have boon dissolved in pure water, one grain was added to 437 grains of a mixture of one part of alcohol to seven of water, and half-minims were placed on the discs of six leaves. Those were not at aU affected, and when after a day bib of meat wore given them, they were slightly inflected in 5 hrs., and closely after 24 lus. It follows from these several facts tlmt a solution of curare induces a very moderate degree of inflection, and this may perhaps be due to the presence of a minute quantity of albumen. It certainly is not poisonous. The protoplasm in one of the leaves, which had been immersed for 24 l1rs., and which had become slightly in: flected, had undergone a very slight amount of aggregationnot more than often ensues from an immersion of this length of time in water. Acetate qf Morphia.-! tried a great number of experiments with this substance, but with no certain result. A considerable number of leaves were immersed from between 2 hrs. and 6 hrs. in a solution of one part to 218 of water, and did not become inflected. Nor were they poisoned; for when they were washed and placed in weak solutions of phosphate and carbonate of ammonia, they soon became strongly in:flected, with the protoplasm in the cells well n,ggregated. If, however, whilst the leaves were immersed in the morphia, phosphate of ammonia was added, in:flection did not rapidly ensue. Minute drops of the solution were applied in the usual manner to the ReCl·etion round between thirty and forty gln,nds; and when, after an interval of 6 m., bits of moat, a little saliva, or particles of glass, were placed on them, the movement of the tentacles was greatly retarded. But on other occasions no such retardation_ occurred. Drops of water similarly applied never have any retarding power. Minute drops of a solution of sugar of the same strength (one part to 218 of water) sometimes retarded the subsequent action of meat and of particles of glass, and |