387 
of simple alimentary substances , &c. 
prepared from gum, which, though exceedingly impure as 
first obtained, may be easily and completely purified by the 
following simple process. 
Add ammonia in slight excess to the impure acid, and 
afterwards as much boiling distilled water as will dissolve the 
saclactate formed. Filter the solution while boiling hot, and 
then evaporate it very slowly nearly to dryness. The 
saclactate of ammonia will be separated in the form of crystals, 
which are to be washed with cold distilled water till they be- 
come quite white and pure. They are now to be again dis- 
solved in distilled water, and the boiling saturated solution 
permitted to drop from a filter into cold diluted nitric acid. 
This latter of course decomposes the saclactate, and preci- 
pitates the saclactic acid in a state of perfect purity. Thus 
obtained, this acid was found to consist of 
Carbon 3 3' 33 
Water 44 '44 
Oxygen 22-22 
results differing a little from those of other chemists, who 
probably did not take the necessary pains to obtain this acid 
in a perfectly pure state. 
In conclusion, I wish to observe, that I purposely abstain 
at present from making any further observations on the 
preceding results than those already given. I do this for 
several reasons : in the first place, such observations will 
appear with greater effect, when the whole of the facts in 
my possession are laid before the public ; and secondly, I 
consider that data which lead to such important conclusions 
