to expect that he would grant—a written
apology for the words he permitted himself to use
to me." The required apology came, frank and
full, creditable alike to the prime minister and
the philosopher.

Next, as to his utter want of greed: Faraday
once confided to Dr. Tyndall that at a
certain period of his career, he was forced definitely
to ask himself, and finally to decide, whether
he should make wealth or science the pursuit
of his life. It was a second Choice of
Hercules. He could not serve both masters; he
was therefore compelled to choose between
them. After the discovery of magneto-
electricity, his fame was so noised abroad that the
commercial world would hardly have considered
any remuneration too high for the aid of
abilities like his. Even before he became so
famous, he had done a little "professional
business." This was the phrase he applied to his
purely commercial work. His friend, Richard
Phillips, for example, had induced him to undertake
a number of analyses, which produced, in
the year 1830, an addition to his income of
more than a thousand pounds; and in 1831 a
still larger sum. He had only to will it,
in 1832, to raise his professional business
income to five thousand a year. This indeed is
a wholly insufficient estimate of what he might,
with ease, have realised annually during the
last thirty years of his life.

Instead of this, Dr. Tyndall states on his
own responsibility, and after the inspection of
Faraday's accounts, that in 1832 his professional
business income dwindled down to one hundred
and fifty-five pounds, nine shillings. From this
it fell, with slight oscillations, to zero in 1838.
Between 1839 and 1845, it never, except in one
instance, exceeded twenty-two pounds, being
for the most part much below that sum. The
exceptional year referred to was that in which
he and Sir Charles Lyell were engaged by
Government to write a report on the Haswell
Colliery explosion; and then his business
income rose to one hundred and twelve pounds.
From the end of 1845 to the day of his death,
Faraday's annual professional business income
was exactly zero. Taking the duration of his
life into account, the son of a blacksmith and
apprentice to a bookbinder had to decide
between a fortune of a hundred and fifty thousand
pounds on the one side, and his undowered
science on the other. He chose the latter, and
died a poor man. But his was the glory of holding
aloft among the nations the scientific name
of England during a period of forty years.

Faraday disliked "doubtful knowledge." He
was possessed of a lively imagination, and could
have believed in the Arabian Nights as easily as
in the Encyclopædia; but facts were important
to him, and saved him. He could trust a fact,
and always cross-examined an assertion. Hence
his habit of testing everything by experiment
and of fixing his attention on the essential
points of the subject under investigation, which
is recorded in Dr. Tyndall's work on Sound.

"By attention," he says, "even the unaided
ear can accomplish this—namely, the resolution
of the clang of an instrument into its
constituent tones—particularly if the mind be
informed beforehand what the ear has to bend
itself to find.

"And this brings to my mind an occurrence
which took place in this room (at the Royal
Institution) at the beginning of my acquaintance
with Mr. Faraday. I wished to show him
a peculiar action of an electro-magnet upon a
crystal. I had everything arranged, when, just
before I excited the magnet, he laid his hand
upon my arm and asked 'What am I to look
for?' Amid the assemblage of impressions
connected with an experiment, even this prince
of experimenters felt the advantage of having
his attention directed to the special point in
question."

The account of Faraday's discoveries here
given is succinct—more so than many readers
would have wished it. Some most interesting
investigations—that, for instance, on the
electricity of the gymnotus—have been left
untouched in the present memoir. Those who
know his charming History of a Candle would
eagerly read his description of the electric eel.
The former has had the honours of translation;
and the translator, M. Henri Sainte-Claire
Deville, justly says, "Michel Faraday" (he was
then still living) "est la plus grande figure
scientifique du temps présent."

Most interesting to the general reader are
the researches into the liquefaction of gases.
We are familiar with solids, as tallow and tin,
which become liquid by the application of no
great amount of heat; others, as ice, pass
readily through the liquid into the vaporous or
gaseous state; but the reverse operation—the
reduction of an ordinary gas to a liquid first,
and then to a solid—is anything but familiar to
the mass of observers. Few dream that a gas
can be rendered even liquid. Faraday
accomplished the feat.

During his hours of liberty from other duties,
he took up subjects of inquiry for himself. In
the spring of 1823, thus self-prompted, he
began the examination of a substance which had
long been regarded as a chemical element—
chlorine in a solid form—but which Sir
Humphry Davy, in 1810, had proved to be
a hydrate of chlorine; that is, a compound of
chlorine and water. Faraday first analysed this
hydrate, and wrote out an account of its
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 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: