Cxap. VILL SALTS OF POTASSIUM. 179 
Potassium, Carbonate of (pure).—Half-minims of a solution 
of one part to 437 of water were placed on six leaves. No 
effect was produced in 24 hrs.; but after 48 hrs. some of the 
leaves had their tentacles, and one the blade, considerably 
inflected. This, however, seemed the result of their being in- 
jured; for on the third day after the solution was given, three of 
the leaves were dead, and one was very unhealthy ; the other 
two were recovering, but with several of their tentacles appa- 
rently injured, and these remained permanently inflected. It 
is evident that the 54, of a grain of this salt acts as a poison. 
Three leaves were also immersed, each in thirty minims of a 
solution of one part to 875 of water, though only for 9 hrs.; and, 
very differently from what occurs with the salts of soda, no 
inflection ensued. 
Potassium, Nitrate of —Half-minims of a strong solution, of 
one part to 109 of water (4 grs. to 1 0z.), were placed on the 
discs of four leaves; two were much injured, but no inflection 
ensued. Hight leaves were treated in the same manner, with 
drops of a weaker solution, of one part to 218 of water. After 
50 brs. there was no inflection, but two of the leaves seemed in- 
jured. Five of these leaves were subsequently tested with drops 
of milk and a solution of gelatine on their discs, and only one 
became inflected; so that the solution of the nitrate of the 
above strength, acting for 50 hrs., apparently had injured or 
paralysed the leaves. Six leaves were then treated in the same 
manner with a still weaker solution, of one part to 487 of water, 
and these, after 48 hrs., were in no way affected, with the excep- 
tion of perhaps a single leaf. Three leaves were next immer-ed 
for 25 hrs., each in thirty minims of a solution of one part to 
875 of water, and 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 con- 
tents 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. 
Potussium, 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. 80 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. Never- 
theless, after two additional days, all six leaves recovered. The 
immersion cf three leaves for 24 hrs., each in thirty minims of 
