CuAP. VIII. THE EFFECTS OF ACIDS. 195 



tentacles were somewhat inflected, and all the glands yery pale- 

 coloured; the surrounding fluid was coloured pink. On one 

 occasion the-fluid became pink in the course of only 12 m., and 

 the glands as white as if the leaf had been dipped in boiling 

 water. After 4 hrs. much inflection ; but none of the tentacles 

 were closely inflected, owing, as I believe, to their having been 

 paralysed before they had time to complete their movement. 

 An extraordinary quantity of mucus was secreted. Some of the 

 leaves were le^ft in the solution ; others, after an immersion of 

 6 hi-s. 30 m., were placed in water. Next morning both lots 

 were quite dead; the leaves in the solution being flaccid, those 

 in the water (now coloured yellow) of a pale brown tint, and 

 their glands white. 



Succinic Acid. — Three leaves were immersed in ninety minims 

 of a solution of 1 gr. to 437 of water ; after 4 hrs. 15 m. consider- 

 able and after 23 hi's. great inflection; many of the glands 

 pale ; fluid coloured pink. The leaves were then washed and 

 placed in water ; after two days there was some re-expansion, 

 but many of the glands were still white. This acid is not 

 nearly so poisonous as oxahc or benzoic. 



Uric Acid. — Three leaves were immersed in 180 minims of a 

 solution of 1 gr. to 875 of warm water, but all the acid was not 

 dissolved; so that each received nearly y\ of a grain. After 

 25 m. there was some slight inflection, but this never increased ; 

 after 9 hrs. the glands were not discoloured, nor was the solu- 

 tion coloured pink; nevertheless much mucus was secreted. 

 The leaves were then placed in water, and by next morning 

 fully re-expanded. I doubt whether this acid really causes 

 inflection, for the shght movement which at first occurred may 

 have been due to the presence of a trace of albuminous matter. 

 But it produces some effect, as shown by the secretion of so 

 much mucus. 



Hippuric Acid.— Four leaves were immersed in 120 minims of 

 a solution of 1 gr. to 437 of water. After 2 hrs. the fluid was 

 coloured pink ; glands pale, but no inflection. After 6 hrs. some 

 inflection; after 9 hrs. all four leaves greatly inflected; much 

 mucus secreted ; all the glands very pale. The leaves were then 

 left in water for two days; they remained closely inflected, 

 with their glands colourless, and. I do not doubt were killed. 



Hydrocyanic Acid. — Four leaves were immersed, each in thirty 

 minims of one part to 437 of water ; in 2 hrs. 45 m. all the 

 tentacles were considerably inflected, with many of the glands 

 pale ; after 3 hrs. 45 m. all strongly inflected, and the surround- 

 ing fluid coloured pink ; after 6 hrs. all closely inflected. After 



