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 hydi'iodic 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 f 

 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. 



Formic 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 httle 

 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 gi'eatly inflected. After 

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

 inflected, the suiTounding 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 



