130 Dr. A. Voelcker on the Chemical Composition of the 
he also detected a trace of organic matter, which caused the 
watery fluid when boiling to emit an odour of boiled apples. 
Though I have examined the water of many pitchers from four 
different localities, and paid particular attention to the detection 
of oxalic acid, I have failed in finding a trace of it, and I am 
therefore inclined to believe that Dr. Turner, on account of the 
minute quantity of solid matter which he must have got on eva- 
poration of the water, was unable to subject the minute crystals 
which he took for superoxalate of potash to a further examina- 
tion, which would have shown him that the crystals were not 
superoxalate of potash, but chloride of potassium. The propor- 
tion of chloride of potassium which I found in the fluid is consider- 
able ; it is deposited from the liquid after evaporation in the form 
of minute but very regular cubes. The odour of boiled apples 
which Dr. Turner observed I found very distinct when the water 
was heated to the boiling-point. Besides chloride of potassium I 
found malic and a little citric acid, in combination usually with 
soda, lime and magnesia, and a small quantity of another orga- 
nic matter which gave a yellow tint to the water during its eva- 
poration. The quantity of the latter was too minute to enable 
me to ascertain its chemical nature. 
I will now proceed to describe the experiments with the dif- 
ferent fluids in the ascidia of Nepenthes :— 
1. Fluid from an unopened pitcher-plant grown in the Bota- 
nical Garden, Edinburgh. 
The water which I got on the 12th of June, 1849, was per- 
fectly colourless and clear ; it had an agreeable, not very pro- 
nounced smell and a refreshing taste. Though its taste was not 
sour, litmus paper showed the presence of an acid or an acid salt 
by the red colour it assumed when dipped in the water. When 
heated it remained clear, and only assumed a slightly yellow 
colour when the liquid became very concentrated. The residue 
which remained on evaporation was cream-coloured, very bygro- 
scopic, and dissolved entirely im a small quantity of distilled 
water. Litmus paper plunged in this solution was turned red 
immediately ; the acid which is present in the water therefore was 
not volatilized during the evaporation. 
The quantity of the water from one pitcher amounted to 
17°41 grains, 
which gave on evaporation 
0:16 of dry residue, dried at 212° F. 
100 parts of the fluid consequently contained 
0:92 per cent. of solid matter. 
2. Water from unopened pitcher-plants grown in the Botani- 
cal Garden, Edinburgh, June 13th, 1849. 
The physical characters.were the same as those of the preceding 
