CHAP. VIII. THE EFFECTS OF ACIDS. 191 



each in thirty minims ; after 3 hrs. strong inflection ; after 4 hrs. 

 glands dark brown ; after 8 hrs. 30 m. close inflection, and the 

 leaves had become flaccid; surrounding fluid not coloured pink. 

 These .leaves were then placed in water, and next day were 

 evidently dead. 



Sulphuric Acid. One to 437 of water; four leaves were im- 

 mersed, each in thirty minims; after 4 hrs. great inflection; 

 after 6 hrs. surrounding fluid just tinged pink ; they were then 

 placed in water, and after 46 hrs. two of them were still closely 

 inflected, two beginning to re-expand; many of the glands 

 colourless. This acid is not so poisonous as hydriodic or iodic 

 acids. 



Phosphoric Acid. One to 437 of water; three leaves were 

 immersed together in ninety minims; after 5 hrs. 30 m. some 

 inflection, and some glands colourless; after 8 hrs. all the 

 tentacles closely inflected, and many glands colourless ; surround- 

 ing fluid pink. Left in water for two days and a half, remained 

 in the same state and appeared dead. 



Boracic Acid. One to 437 of water; four leaves were im- 

 mersed together in 120 minims ; after 6 hrs. very slight inflection ; 

 after 8 hrs. 15 m. two were considerably inflected, the other two 

 slightly. After 24 hrs. one leaf was rather closely inflected, 

 the second less closely, the third and fourth moderately. The 

 leaves were washed and put into water ; after 24 hrs. they 

 were almost fully re-expanded and looked healthy. This acid 

 agrees closely with hydrochloric acid of the same strength in 

 its power of causing inflection, and in not being poisonous. 



Frmic Acid. Four leaves were immersed together in 120 

 minims of one part to 437 of water ; after 40 m. slight, and after 

 6 hrs. 30 m. very moderate inflection ; after 22 hrs. only a little 

 more inflection than often occurs in water. Two of the leaves 

 were then washed and placed in a solution (1 gr. to 20 oz.) of 

 phosphate of ammonia; after 24 hrs. they were considerably 

 inflected, with the contents of their cells aggregated, showing 

 that the phosphate had acted, though not to the full and 

 ordinary degree. 



Acetic Acid. Four leaves were immersed together in 120 

 minims of one part to 437 of water. In 1 hr. 20 m. the tentacles 

 of all four and the blades of two were greatly inflected. After 

 8 hrs. the leaves had become flaccid, but still remained closely 

 inflected, the surrounding fluid being coloured pink. They were 

 then washed and placed in water ; next morning they were still 

 inflected and of a very dark red colour, but with their glands 

 colourless. After another day they were dingy-coloured, and 



