1816.] during the Year 1815. 37 
properties. In short, Brandenburg seems to be of opinion that no 
such substance as chromic acid exists. As the subject is of consi- 
derable importance in a chemical point of view, I shall insert either 
the whole of Brandenburg’s paper, or. at least a full abstract of it, 
in a future number of the Annals of Philosophy. 
8. Oxalic Acid.—It is well known, I presume, to most of my 
readers, that Mr. Royston published some time ago in the Medical 
Repository, the case of a young lady who died in 40. minutes in 
consequence of swallowing half an ounce of crystals of oxalic acid 
instead of sulphate of magnesia. M. Guyton-Moryeau, who has 
given an account of this remarkable fact in the Ann. de Chim. (vol. 
xciii, p. 199), seems to entertain some doubts whether the death of 
the young lady was owing to the oxalic acid or not. Perhaps I do 
not understand his meaning; but he terminates his observations 
with the following remark: “¢ It is difficult to avoid believing that 
in the administration of the remedy there took place one of those 
mistakes which unfortunately are too common, and that every thing 
done afterwards had less for its object to discover the truth than to 
destroy suspicion.” 
Whatever Morveau may mean by this paragraph, there can be 
no doubt that oxalic acid acts asa violent poison when taken inter- 
nally; for Mr. Anthony ‘Tod Thomson, surgeon in Sloane-street, 
and one of the editors of the London Medical Repository, gave it 
to dogs and other animals, and it never failed to prove fatal in a 
short time. 
9. Sorbic Acid.—This is an acid lately discovered by Mr. Dono- 
yan in the berries of the pyrus aucuparia. He obtained it by the 
following process. The berries are bruised, and their juice squeezed 
out. This juice, being strained, is mixed with a filtered solution 
of acetate of lead. The precipitate is collected on a filter, and 
edulcorated with cold water. ‘Then a very large quantity of boiling 
water is poured on the filter, and collected in glass jars. After 
some hours, this liquid deposits crystals of singular lustre and 
beauty. These crystals are collected, and boiled with a quantity of 
very dilute sulphuric acid not sufficient to saturate all the lead. The 
liquid is then set aside for some days. ‘The sulphate of lead depo- 
sited being separated, a current of sulphureted hydrogen gas is 
passed through the liquid. The sulphuret of lead formed is sepa- 
rated, and the liquid boiled till the excess of sulphureted hydrogen 
is driven off. ‘The water now contains nothing but sorbic acid. 
This acid is colourless, without smell, and having an intensely 
acid taste. It dissolves in alcohol, and is very soluble in water, 
When evaporated to dryness, it leaves an uncrystallizable residuum, 
which deliquesces. When distilled, the liquor that passes over is 
not acid. It may be kept for a considerable length of time without 
undergoing decomposition. It decomposes malate of lead. It 
combines in three proportions with oxide of lead, forming super- 
sorbate, which can only be obtained in a liquid state; sorbate, which 
constitutes the beautiful silky crystals from which the acid was ob- 
