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 atropine to 437 of water.  Half-minims of these three solutions 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 slightly 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 became in 24 hrs. fairly well inflected; so that atropine does not excite movement, and is not poisonous.  I also tried in the same manner the alkaloid sold as daturine, which is believed not to differ from atropine, and it produced no effect.  Three 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 inflected.

Veratrine, Colchicine, Theine.—­Solutions were made of these three alkaloids by adding one part to 437 of water.  Half-minims were placed, in each case; on the discs of at least six leaves, but no inflection was caused, except perhaps a very slight amount by the theine.  Half-minims of a strong infusion of tea likewise produced, as formerly stated, no effect.  I also tried similar drops of an infusion of one part of the extract of colchicum, 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 meat, and after 21 hrs. were well inflected.  These three alkaloids are therefore quite innocuous.

Curare.—­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 blackened, showing that matter of some kind had been absorbed.  In 9 hrs. two of the leaves had most of their tentacles sub-inflected, 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; [page 205] the other two, after their immersion for 24 hrs., were likewise placed in water, and in 24 hrs. were considerably re-expanded, though their glands were as black as ever.  Half-minims were placed on the discs of six leaves, and no inflection ensued; but after three days the glands on the discs appeared rather dry, yet to my surprise were not blackened.  On another occasion drops were placed on the discs of six leaves, and a considerable amount of inflection was soon caused; but as I had not filtered the solution,