There can, therefore, be no doubt about the efficiency of the above solution; and it follows as before that each gland of No. 1 could have absorbed only 1/2412000 of a grain (.0000268 mg.) and of No. 2 only 1/2460000 of a grain (.0000263 mg.) of the phosphate.
Seven leaves were immersed, each in thirty minims of a solution of one part to 437,500 of water (1 gr. to 1000 oz.). Each leaf thus received 1/16000 of a grain (.00405 mg.). The day was warm, and the leaves were very fine, so that all circumstances were favourable.
(1) After 30 m. all the outer tentacles except five inflected, and most of them closely; after 1 hr. blade slightly inflected; after 9 hrs. 30 m. began to re-expand.
(2) After 33 m. all the outer tentacles but twenty-five inflected, and blade slightly so; after 1 hr. 30 m. blade strongly inflected and remained so for 24 hrs.; but some of the tentacles had then re-expanded.
(3) After 1 hr. all but twelve tentacles inflected; after 2 hrs. 30 m. all but nine inflected; and of the inflected tentacles all excepting four closely; blade slightly inflected. After 8 hrs. blade quite doubled up, and now all the tentacles excepting [page 162] eight closely inflected. The leaf remained in this state for two days.
(4) After 2 hrs. 20 m. only fifty-nine tentacles inflected; but after 5 hrs. all the tentacles closely inflected excepting two which were not affected, and eleven which were only sub-inflected; after 7 hrs. blade considerably inflected; after 12 hrs. much re-expansion.
(5) After 4 hrs. all the tentacles but fourteen inflected; after 9 hrs. 30 m. beginning to re-expand.
(6) After 1 hr. thirty-six tentacles inflected; after 5 hrs. all but fifty-four inflected; after 12 hrs. considerable re-expansion.
(7) After 4 hrs. 30 m. only thirty-five tentacles inflected or sub-inflected, and this small amount of inflection never increased.
Now for the seven corresponding leaves in water:—