composition. This account was looked over
by Davy, who suggested the heating of the hydrate under pressure in a
sealed glass tube. This was done. The hydrate fused at a blood-heat, the
tube became filled with a yellow atmosphere, and was afterwards found
to contain two liquid substances. Dr. Paris happened to enter the
laboratory while Faraday was at work. Seeing the oily liquid in his
tube, he rallied the young chemist for his carelessness in employing
soiled vessels. On filing off the end of the tube, its contents exploded
and the oily matter vanished. Early next morning, Dr. Paris received the
following note:--

'Dear Sir,--The oil you noticed yesterday turns out to be liquid
chlorine.

'Yours faithfully,

'M. Faraday.'[2]

The gas had been liquefied by its own pressure. Faraday then tried
compression with a syringe, and succeeded thus in liquefying the gas.

To the published account of this experiment Davy added the following
note:--'In desiring Mr. Faraday to expose the hydrate of chlorine in
a closed glass tube, it occurred to me that one of three things would
happen: that decomposition of water would occur;... or that the chlorine
would separate in a fluid state.' Davy, moreover, immediately applied
the method of self-compressing atmosphere to the liquefaction of
muriatic gas. Faraday continued the experiments, and succeeded in
reducing a number of gases till then deemed permanent to the liquid
condition. In 1844 he returned to the subject, and considerably expanded
its limits. These important investigations established the fact
that gases are but the vapours of liquids possessing a very low
boiling-point, and gave a sure basis to our views of molecular
aggregation. The account of the first investigation was read before the
Royal Society on April 10, 1823, and was published, in Faraday's name,
in the 'Philosophical Transactions.' The second memoir was sent to
the Royal Society on December 19, 1844. I may add that while he was
conducting his first experiments on the liquefaction of gases, thirteen
pieces of glass were on one occasion driven by an explosion into
Faraday's eye.

Some small notices and papers, including the observation that glass
readily changes colour in sunlight, follow here. In 1825 and 1826
Faraday published papers in the 'Philosophical Transactions' on 'new
compounds of carbon and hydrogen,' and on 'sulphonaphthalic acid.' In
the former of these papers he announced the discovery of Benzo