doze, with the expectation of awakening
relieved of a torment or a burden, can make a
surgical operation, it has, at last, been
rendered. Everybody is aware that, during the
extraordinary slumber induced by the inhalation
of chloroform, operations of the first
magnitude and the greatest difficulty may be
painlessly undergone. Consciousness is
suspended, sensation placed in abeyance. Muscles,
tendons, bones, even nerves, are cut and sawn
through with little or no inconvenience to
their proprietor. A man is lopped and pruned
like a tree; he is carved and hewn, and
squared, as if he were a log; and is, indeed, the
mere apathetic subject of medical carpentry.

Whilst the bodily edifice is under surgical
repair, for the advantage of being enabled to
avoid the annoyance attending the cognizance
of that process, by taking, with ease and
convenience, an excursion into the land of
sleep, every lifeholder of the tenement in
question is indebted to Dr. Simpson of
Edinburgh  The peculiar power of chloroform to
produce insensibility, was determined by his
researches. For some time previously,
sulphuric ether, the discovery of Dr. Jackson
and Mr. Morton of Boston, in America, had
been in use for the same purpose. There
were, however, objections to its employment.
A larger quantity of it than was consistent with
safety, required occasionally to be administered
to produce the desired efi'ect. Its odour was
disagreeably strong and permanent; and,
what was worse, it not unfrequently excited
irritation in the chest. In search, therefore,
of a more safe and commodious anaesthetic
agent, Dr. Simpson tried a series of experiments,
principally on his own person, with a
variety of volatile substances; and the result
was, his announcement, in 1847, of the
desideratum as being supplied by chloroform.

The existence of this substance, chloroform,
had been known to chemists since 1831,
in which year it was discovered by Soubeiran.
Very little later, in 1832, an independent
discovery of it was made by Liebig. Dumas,
in 1835, was the first to ascertain its exact
chemical composition.

When, in our nursery days, we used to
read of some wonderful balsam, by means
whereof well-disposed magicians and benevolent
fairies were wont to charm away the pain
of injuries inflicted by dragons and ogres on
the persons of good knights and serviceable
giant-killers, a very natural desire arose in
our minds for information concerning the
nature and composition of the marvellous
remedy. Those who are not conversant with
chemical details, and who may, in spite of
hope to the. contrary, one day have a tooth
to be extracted, or a nail to be plucked out—-
not to suggest more formidable interference
of a manual or anatomical description with
the living mechanism—- will probably feel a
similar, and at least an equal curiosity, with
regard to the rather more practically
interesting subject of chloroform.

Chloroform is a bright colourless liquid,
in appearance resembling spirit of wine,
which it further resembles in being extremely
volatile, but differs from it remarkably in
being much more dense; for it is considerably
heavier than water, in which it sinks. Unlike
spirit of wine, too, it is not inflammable. It
has an agreeable, fragrant, etherial, fruit-like
smell, very similar to that of a ripe apple;
and a sweet taste. Chloroform boils at one
hundred and forty-one degrees, and its
vapour exceeds in density that of the
atmosphere in somewhat above the proportion of
four to one. The ready volatility of a fluid
comparatively so ponderous as chloroform
may appear singular.

Chloroform, considered as a noun-substantive,
may be said to be an abbreviation—- not
to employ the more equivocal expression,
alias. In legal phraseology—- according to the
statutes of chemistry—- it is called per-chloride
of formyle, signifying formyle united with its
maximum of chlorine. More strictly still, it is
denominated ter-chloride instead of per-chloride,
to denote that the proportions in which
the chlorine is combined with the formyle are
three of the former to one of the latter. Now,
formyle is a substance supposed to be the
base, or fundamental, or essential constituent
part of an acid called formic acid. Formic
acid is so termed from having been first
discovered in red ants, the Latin for ant being
formica; it consists of three proportions of
oxygen, in combination with one of hydrogen
and two of carbon. But if such is the
composition of formic acid, what, it will be asked,
was meant by the statement that its base is
formyle? This seeming puzzle is solved by
the explanation, that formyle is not conceived
to be a simple element, but a substance
analogous to one, constituted by the two
proportionals of carbon and one of hydrogen in
the formic acid. Here it must be remembered
that a chemical compound differs essentially
from a mechanical mixture. Things mixed
mechanically are separable particle from
particle; sulphur from charcoal; chalk from
cheese. In a chemical compound, the least
particle that can be got by mechanical
subdivision contains the same chemical
constituents as the whole mass. The smallest
conceivable quantity, for instance, of formyle,
consists of carbon and hydrogen. Formyle
has never been produced separately, so as to
be shown by itself; but chemists, on certain
theoretical grounds, conclude that the carbon
and the hydrogen of the formic acid exist
therein in a state of special combination, as a
distinct thing; so that formic acid consists
not in a mutual partnership between carbon,
oxygen, and hydrogen individually, but of
a particular arrangement of carbon and
hydrogen on the one hand—- making formyle
—- with respect to oxygen on the other. In
like manner, also, Chloroform is ultimately
resolvable into chlorine, hydrogen, and carbon;
the formyle, to which the three parts of