1815.) Philosophical Transactions, 1814, Part II. 139 
XT. On the Nature of the Salts called Triple Prussiates, and on 
Acids formed by the Union of certain Bodies with the Elements of 
the Prussic Acid. By Robert Porrett, jun. Esq.—1 have already 
given a pretty full account of this important paper in the number of 
the Annals of Philosophy for January, 1815, to which I refer the 
readers. I intend to publish an abridgment of the paper in a future 
number of the Annals, as it contains some discoveries which I con- 
sider as important. 
XIU. Some Experiments on the Combustion of the Diamond, and. 
other Carbonaceous Substances. By Sir H. Davy.—Diamonds were 
put in a small glass globe filled with oxygen gas, and kindled by 
means of a buruing-glass. When once set on fire, they were found 
to burn, though removed out of the focus of the lens. The result 
of the experiments was, that diamonds, when burnt, produced 
only carbonic acid gas, and no alteration took place in the bulk of 
the gas in which the combustion was performed. Hence it follows 
that the diamond consists of pure carbon. Plumbago and charcoal, 
besides carbonic acid, formed also a sensible portion of water when 
burnt, and the bulk of the oxygen gas was diminished. Hence these 
bodies contain hydrogen as a constituent, though only in a very 
minute proportion. 
XIV. Some Account of the Fossil Remains of an Animal more 
nearly allied to Fishes than to any other Class of Animals. By Sir 
fverard Home, Bart. F.R.S.—These bones were found in a cliff 
on the sea coast of Dorsetshire. The skull was pretty perfect; most 
of the other bones were broken and crushed. The ribs were 60, 
and make the skeleton 17 feet long. ‘These bones approach most 
nearly to those of fishes, though the author considers the animal as 
not having been a perfect fish, but as constituting one of those in- 
termediate links so commonly observed in the animals of New South 
Wales. 
XV. On an easier Mode of procuring Potassium than that which 
is now adopted. By Smithson Tennant, Esq. F. R.S. — This 
method is to put the potash and iron turnings together into a gun- 
barrel about a foot and a half long, and covered with a lute com- 
posed of Stourbridge clay, partly in its natural state, and partly pre- 
viously baked. Into the mouth of the guo-barrel another iron tube 
about eight inches long is to be put, perforated at the lower extre- 
mity, and having its upper end projecting about an inch beyond 
the gun-barrel. The mouth of the gun-barrel is shut by another 
tube which slips over it. ‘The mouth of it is filled by a perforated 
cork, through which there passes a bent glass tube, having in ita 
drop of mercury. ‘This apparatus being exposed to a strong heat 
for an hour in a smith’s forge, the potassium is found perfectly pure 
in the upper perforated iron tube. 
XVI. On the Influence of the Nerves upon the Action of the 
Arteries. By Sir Everard Home, Bart. F.R.S.—Our author acci- 
dentally observed that the application of stimulants to nerves pro- 
duced a violent increase of the action of the blood-vessels connected 
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