182 DROSERA ROTUNDIFOLIA. CHAP. VIII 



minims of a solution of one part to 437 of \vater; so that each 

 received, as before, -^ of a grain. After 5 m. slight inflection, 

 and after 11 m. very strong inflection, the glands becoming 

 excessively black; after 40 m. all the tentacles were closely 

 inflected. After 6 hrs. the leaves were taken out of the solution, 

 washed, and placed in water ; but next morning they were 

 evidently dead. 



Calcium, Acttute of. Four leaves were immersed in 120 minims 

 of a solution of one part to 437 of water ; after 24 hrs. none of 

 the tentacles were inflected, excepting a few where the blade 

 joined the petiole ; and this may have been caused by the 

 absorption of the salt by the cut-off end of the petiole. I then 

 added some of the solution (1 gr. to 20 oz.) of phospate of 

 ammonia, but this to my surprise excited only slight inflection, 

 even after 24 hrs. Hence it would appear that the acetate had 

 rendered the leaves torpid. 



Calcium, Nitrate, of. Four leaves were immersed in 120 minims 

 of a solution of one part to 437 of water, but were not affected 

 in 24 hrs. I then added some of the solution of phosphate of 

 ammonia (1 gr. to 20 oz.), but this caused only very slight in- 

 flection after 24 hrs. A fresh leaf was next put into a mixed 

 solution of the above strengths of the nitrate of calcium and 

 phosphate of ammonia, and it became closely inflected in between 

 5 m. and 10 m. Half-minims of a solution of one part of the 

 nitrate of calcium to 218 of water were dropped on the discs of 

 three leaves, but produced no effect. 



Magnesium. Acetate, Nitrate, and Chloride of. Four leaves were 

 immersed in 120 minims of solutions, of one part to 437 of water, 

 of each of these three salts ; after 6 hrs. there was no inflection ; 

 but after 22 hrs. one of the leaves in the acetate was rather more 

 inflected than generally occurs from an immersion for this 

 length of time in water. Some of the solution (1 gr. to 20 oz.) 

 of phosphate of ammonia was then added to the three solutions. 

 The leaves in the acetate mixed with the phosphate underwent 

 some inflection; and this was well pronounced after 24 hrs. 

 Those in the mixed nitrate were decidedly inflected in 4 hrs. 

 30 m., but the degree of inflection did not afterwards much 

 increase ; whereas the four leaves in the mixed chloride were 

 greatly inflected in a few minutes, and after 4 hrs. had almost 

 every tentacle closely inflected. We thus see that the acetate 

 and nitrate of magnesium injure the leaves, or at least prevent 

 the subsequent action of phosphate of ammonia; whereas the 

 chloride has no such tendency. 



