Fluid in the Ascidia of Nepenthes. 133 
must have resulted from the water with which the plants had 
been watered which had found its way into the open _pitchers*. 
In order to see if the liquid contained any volatile acid, I sub- 
jected about half an ounce of it to distillation. The distillation 
was continued till the residue in the glass retort was evaporated 
to dryness, and the generated steam carefully condensed in a 
glass receiver. The distilled portion was pertectly pure water, 
and experienced no change by any reagent. 
It results from this experiment that the liquid in the ascidia 
of Nepenthes does not contain any volatile acids, such as acetic or 
formic acid. 
8. Fluid from unopened pitcher-plants grown in the Royal 
Gardens, Kew. _ 
Having been unable to detect any oxalic acid in the above- 
mentioned fluids, I was anxious to ascertain whether or not the 
fluid of plants grown in other localities contained oxalic acid. I 
therefore applied to Sir W. Hooker, who with great liberality di- 
rected some liquid of unopened pitcher-plants grown in the Kew 
Royal Botanical Gardens to be sent to me. The physical and 
chemical characters of this fluid were precisely the same as those 
of the previously examined liquids. The proportion of solid 
matter it held in solution however was much smaller. 
299°87 grains of the liquid left on evaporation only 
0°82 of a grain of dry residue. 
100 parts of the liquid therefore contained 
0:27 per cent. of solid matter. 
On burning, the 0°82 of a grain lost 0°27 of a grain, or 
100 parts lost 32°92 per cent. 
All the liquids from the different localities above-mentioned 
which were left over I mixed together and evaporated the mix- 
ture to dryness. One-half of the dry residue I exposed to a red 
heat, and used the remaining white ash for the determination of 
the inorganic salts of which it was composed. 
The other half [ dissolved in water and precipitated with basic 
acetate of lead, in order to obtain the organic acids in combina- 
tion with lead. This precipitate I collected on a filter and washed 
with cold distilled water. It was then removed from the filter 
and suspended in water, through which a current of sulphuretted 
hydrogen was passed. By this means I separated the lead as 
sulphuret, and obtained the organic acids free dissolved in water. 
This solution was colourless and very acid ; evaporated to a small 
bulk in a water-bath it assumed a yellow colour, and dried at last 
to a yellow crystalline mass, which deliquesced in the air and dis- 
* The water in this instance was procured chiefly from the Water of 
Leith. 
