this produced no apparent effect. They were then put into a solution of
one part of carbonate of ammonia to 218 of water; the glands were
immediately blackened, and after 1 hr. there was some inflection, and
the protoplasmic contents of the cells became plainly aggregated. This
shows that the leaves had not been much injured by their immersion for
25 hrs. in the nitrate.
Potassium, Sulphate of. Half-minims of a solution of one part to 437 of
water were placed on the discs of six leaves. After 20 hrs. 30 m. no
effect was produced; after an additional 24 hrs. three remained quite
unaffected; two seemed injured, and the sixth seemed almost dead with
its tentacles inflected. Nevertheless, after two additional days, all
six leaves recovered. The immersion of three leaves for 24 hrs., each
in thirty minims of [page 180] a solution of one part to 875 of water,
produced no apparent effect. They were then treated with the same
solution of carbonate of ammonia, with the same result as in the case
of the nitrate of potash.
Potassium, Phosphate of. Half-minims of a solution of one part to 437
of water were placed on the discs of six leaves, which were observed
during three days; but no effect was produced. The partial drying up of
the fluid on the disc slightly drew together the tentacles on it, as
often occurs in experiments of this kind. The leaves on the third day
appeared quite healthy.
Potassium, Citrate of. Half-minims of a solution of one part to 437 of
water, left on the discs of six leaves for three days, and the
immersion of three leaves for 9 hrs., each in 30 minims of a solution
of one part to 875 of water, did not produce the least effect.
Potassium, Oxalate of. Half-minims were placed on different occasions
on the discs of seventeen leaves; and the results perplexed me much, as
they still do. Inflection supervened very slowly. After 24 hrs. four
leaves out of the seventeen were well inflected, together with the
blades of two; six were slightly affected, and seven not at all. Three
leaves of one lot were observed for five days, and all died; but in
another lot of six, all excepting one looked healthy after four days.
Three leaves were immersed during 9 hrs., each in 30 minims of a
solution of one part to 875 of water, and were not in the least
affected; but they ought to have been observed for a longer time.
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