134 Dr. A. Voelcker on the Chemical Composition of the 
solved readily in water and alcohol, leaving behind a trace of a 
brown organic matter. 
Lime-water added in excess to a portion of the acid solution 
produced no precipitate in the cold, but on boiling a small white 
precipitate fell down which redissolved entirely in sal ammoniac. 
Chloride of calcium and ammonium left the liquid unchanged 
in the cold, but on boiling a precipitate was formed which was 
soluble in sal ammoniac. 
Acetate of lead gave a white precipitate insoluble in ammonia, 
soluble in acetic acid. 
Basic acetate of lead added to the liquid filtered from the pre- 
cipitate caused by neutral acetate of lead produced another abun- 
dant white precipitate. From these reactions it appears that the 
precipitate with lime-water was caused by citric acid and not by 
tartaric or racemic acid, the reactions of which acids are similar 
to those of citric acid, for tartrate of lime is not soluble in sal 
ammoniac, whilst tartrate of lead redissolves readily in ammonia. 
Tartaric acid moreover is sufficiently characterized by the sparmg 
solubility of its acid potash salt, and as the acid liquid did not 
give rise to the formation of such a salt with potash, we have 
another indirect proof of the presence of citric acid. A little 
tartaric acid added to the liquid in which tartaric acid was sought 
in vain, after a few minutes produced the sparingly soluble pot- 
ash salt. 
Racemic acid is thrown down both by lime-water and by a 
solution of gypsum ; the acid liquid of Nepenthes remained un- 
changed by either reagent, hence it cannot have contained any 
racemic acid. 
The precipitate caused by chloride of calcium and ammonia 
and boiling was filtered hot, and alcohol and ammonia added to 
the clear liquid. The addition of alcohol produced a voluminous 
white precipitate, a reaction which indicates the presence of malic 
acid. The quantity of this precipitate was much larger than that 
of the lime precipitate which citric acid gave. The formation of 
a precipitate, upon addition of aleohol to the hquid from which 
the first had been separated by filtration, is characteristic of the 
presence of malic acid, for no other lime-salts were present ; for 
instance, no sulphate of lime was present which could have pro- 
duced a precipitate. But I thought it nevertheless necessary 
to examine the precipitate caused by the addition of alcohol 
further. When burnt it turned black, gave off pungent vapours, 
and was converted into carbonate of ime. The solution of chlo- 
ride of calctum and ammonia used for the experiment remained 
elear after the addition of alcohol; the acid liquid likewise re- 
mained clear when alcohol was added ; both put together imme- 
diately produced a white voluminous precipitate. 
