180 . DROSERA ROTUNDIFOLIA. Car. VIIL 
a solution of one part to 875 of water, produced no apparcut 
effect. They were then treated with the same solution of car- 
bonate 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 487 of water were placed on the discs of six leaves, 
which were observed during three days ; but no effect was pro- 
duced. The partial drying up of the fluid on the disc slightly 
drew together the tentacles on it, as often occurs in experi- 
ments of this kind. The leaves on the third day appeared quite 
healthy. 
Potassium, Citrate of —Half-minims of a solution of one part 
to 487 of water, left on the discs of six leaves for three days, 
and the immersion of three leaves for 9 hrs., each in 80 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 per- 
plexed 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 heen observed for a 
longer time. 
Potassium, Chloride of. Neither half-minims of a solution of 
one part to 437 of water, left on the dises of six leaves for three 
days, nor the immersion of three leaves during 25 hrs., in 
30 minims of a solution of one part to 875 of water, produced 
the least effect. The immersed leaves were then treated with 
carbonate of ammonia, as described under nitrate of potash, and 
with the same result. : 
Potassium, Iodide of—Half-minims of a solution of one part 
to 437 of water were placed on the discs of seven leaves. In 
30 m. one leaf had the blade inflected ; after some hours three 
leaves had most of their submarginal tentacles moderately in- 
flected; the remaining three being very slightly affected. 
Hardly any of these leaves had their outer tentacles inflected. 
After 21 hrs. all re-expanded, excepting two which still had a 
few submarginal tentacles inflected. Three leaves were next 
