Chemistry. lui 
world a pretty considerable number of experiments on this sub- 
stance in the article Tannin, published in the chemical part of 
the Encyclopedie Methodique, in 1815; but that he had neg- 
lected to give it a name; nor does he seem to have been aware that 
it was entitled to be considered as a peculiar acid. This acid 
was obtained by taking the powder separated by filtering the 
solution of gallic acid obtained from the crystals that had formed 
spontaneously in the infusion of nutgalls. To free it from gallate 
of lime, &c. with which it was mixed, it was treated with a 
dilute solution of potash, which dissolved the acid with the 
evolution of a considerable quantity of heat, the solution had an 
intense yellow colour, and gradually let fall a pretty copious 
quantity of pearl-coloured powder, which was separated by the 
filte , and decomposed by dilute muriatic acid: The ellagic 
acid thus obtained is a white powder, with a slight shade of buff. 
It is insipid, and is not sensibly soluble in water even when boil- 
ing hot. It does not decompose the alkaline carbonates even 
when assisted by heat; but it unites with caustic soda, and 
potash, and destroys their alkaline properties. These salts are 
insoluble in water, but they become soluble if a little potash or 
soda be previously dissolved in that liquid. The solution is very 
dark buff coloured. The ellagate of ammonia is likewise inso- 
luble, and does not become soluble even when an excess of 
ammonia is added. It separates the lime when agitated in lime- 
water. Nitric acid does not seem to act upon it at first, but it 
gradually gives that acid a red colour similar to that of blood. 
If the action be continued, a good deal of oxalic acid is formed. 
It does not combine with iodine. When heated, it does not 
melt, but burns away with a sort of scintillation without emitting 
flame. When distilled, it leaves charcoal, and produces a yellow 
vapour, which condenses into transparent crystals, of a fine 
greenish-yellow colour. This sublimate is tasteless, and insoluble 
in water, alcohol, and ether ; butit dissolves readily in a solution 
of potash, and communicates a yellow colour. 1a short, the 
yellow crystals possess nearly the characters of the ellagic acid 
itself.—(Ann. de Chim. et Phys. ix. 187.) 
14. Lampic Acid.—This is the name by which Mr. Daniell 
has thought proper to distinguish a peculiar acid substance 
which Sir Humphry Davy recognized as formed when ether is 
decomposed by the continued action of a red-hot platinum wire, 
This acid was examined by Mr. Faraday, but upon too small a 
scale to admit of accurate conclusions. Mr. Daniell succeeded 
in obtaining it in considerable quantities by means of the well- 
known lamp without flame, or the spirit lamp, which keeps a 
coil of platinum wire red-hot by the slow combustion of alcohol 
orether. He put this lamp in the head of an alembic, to which 
a receiver was adapted, and by keeping the slow combustion 
going for a considerable time (he mentions havmg continued it 
or six weeks at one time), he collected considerable quantities of 
