Fluid in the Ascidia of Nepenthes. 135 
Basic acetate of lead, as already mentioned, throws down from 
the solution a white precipitate. I could not observe that this pre- 
cipitate melted below the boiling-point of water, as pure malate of 
lead does, but it must be remembered that this reaction is di- 
stinctly marked only when the malate of lead is pure ; admixtures 
of other salts of lead prevent it altogether ; and as I have shown 
the presence of citric acid and another organic substance which 
is thrown down by basic acetate of lead, there can be no doubt 
that this was the reason why the precipitate did not dissolve in 
boiling water. 
Though I have not been able to obtain a sufficient quantity of 
the acids of Nepenthes for an elementary analysis, I think the above 
reactions prove the presence of malic and citric acid. Oxalic acid, 
which is readily detected, as the weakest solution of an oxalate is 
thrown down by lime-water, I failed to discover; on the contrary, I 
have shown that the water contained lime, which excludes the co- 
existence of oxalic acid in a clear liquid. I have found that the 
smallest quantity of oxalic acid immediately caused the water of 
Nepenthes to become turbid. : 
The second half of the residue left on evaporation of the mixed 
fluids I exposed to a red heat in a platinum capsule. It turned 
black, gave off pungent fumes, and left a white salt after all the 
charcoal was burnt off. 
On analysis this residue was found to consist of 
Chloride of potassium. . . . . 76°31 
Carbonate of soda’. 4. |. 16°44: 
Uhntiee et ise wk Om 
MOMENI A Lica ieeih Vesta oo. cn) Seen 
100°63 
The unburnt residue left on evaporation of the fluid in the 
ascidia of Nepenthes therefore consists, if we take the average of 
the loss of the three determinations at 31°61 per cent. and reject 
the earbonic acid of the ash, of— 
Organic matter, chiefly 
Malic acid and a little citric acid . 38°61 
Chloride of potassium . . . . 50°42 
Oeler Meee! th. Se Bens Soe eG 
Riirrtegys Freer men PSE ee 2°59 
MIRC MIESIAS Weve: es. oc oe ee ee oo 
100°57 
It is remarkable that none of the fluids which I examined 
contained any sulphuric acid, which acid has been found in all 
juices of plants, and which I do not doubt also exists in the sap 
