This acid is not nearly so poisonous as oxalic 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 1/16 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 solution 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 slight 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 surrounding fluid coloured pink;
after 6 hrs. all closely inflected. After [page 196] an immersion of 8
hrs. 20 m. the leaves were washed and placed in water; next morning,
after about 16 hrs., they were still inflected and discoloured; on the
succeeding day they were evidently dead. Two leaves were immersed in a
stronger mixture, of one part to fifty of water; in 1 hr. 15 m. the
glands became as white as porcelain, as if they had been dipped in
boiling water; very few of the tentacles were inflected; but after 4
hrs. almost all were inflected. These leaves were then placed in water,
and next morning were evidently dead. Half-minim drops of the same
strength (viz. one part to fifty of water) were next placed on the
discs of five leaves; after 21 hrs. all the outer tentacles were
inflected, and the leaves appeared much injured. I likewise touched the
secretion round a large number of glands with minute drops (about 1/20
of a minim, or .00296 ml.) of Scheele s mixture (6 per cent.); the
glands first became bright red, and after 3 hrs. 15 m. about two-thirds
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