156 DROSERA ROTUNDIFOLIA. [Chap. VUI. 



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

 mersed each in thirty minims; after 4 hrs. great inllcction; after 

 hrs. surrounding liuid just tinged pink; they were then placed 

 in water, and after 40 hrs. two of them were still closely inllected, 

 two beginning to re-expand; many of the glands colourless. Thia 

 acid is not so poisonous as hydriodic or iodic acids. 



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

 mersed together in ninety minims; after 5 hrs. 30 m. some inflec- 

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

 closely inflected, and many glands colourless; surrounding 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 wei-e immersed 

 together in 120 minims; after 6 hrs. very slight inflection; after 8 

 hrs. 15 m. two were considerably inflected, the otiier 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-ex- 

 panded and looked healthy. This acid agrees closely with hy- 

 drochloric acid of the same strength in its power of causing inflec- 

 tion, and in not being poisonous. 



Formic Acid. Four leaves were immersed together in 120 min- 

 ims 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 min- 

 ims 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 evidently dead. 

 This acid is far more powerful than formic, and is highly poisonous. 

 Half-minim drops of a stronger mixture (viz. one part by measure 

 to 320 of water) were placed on the discs of five leaves; none of 

 the exterior tentacles, only those on the borders of the disc which 

 actunlly absorbed the acid, became inflected. Probably the dose 

 was too strong and paralysed the leaves, for drops of a weaker 

 mixture caused much inflection; nevertheless, the leaves all died 

 after two days. 



Propionic Acid. Three leaves were immersed in ninety minims 

 of a mixture of one part to 437 of water; in 1 hr. 50 m. there was 

 no inflection; but after 3 hrs. 40 m. one leaf was greatly inflected, 

 and the other two slightly. The inflection continued to increase, 

 BO that in 8 hrs. all three leaves were closely inflected. Next 

 morning, after 20 hrs., most of the glands were very pale, but some 



