Chronology

Sweet oil of vitriol described

Valerius Cordus records the preparation of the liquid later called ether; its effect on animals is noticed but not pursued.

Nitrous oxide prepared

Joseph Priestley produces the gas during his survey of newly isolated airs.

Davy publishes his Researches

The book describes the gas at length and remarks that it might be used during surgical operations.

Hickman argues for suspended animation

A letter proposes that insensibility could be induced deliberately to permit painless surgery.

Ether used in Georgia

Crawford Long removes a neck tumour under ether; the case is not published for seven years.

Nitrous oxide used for a dental extraction

Horace Wells has his own tooth removed under the gas after seeing an exhibition of its effects.

The failed demonstration

Wells attempts a public demonstration in Boston; the patient cries out and the method is dismissed.

The Boston ether demonstration

On 16 October, ether is administered before an operation performed by John Collins Warren; the report circulates within weeks.

The word anaesthesia proposed

Oliver Wendell Holmes suggests a name for the new state in a letter written in November.

Ether reaches Europe

Robert Liston operates under ether in London in December, two months after the Boston case.

Chloroform introduced

James Young Simpson reports chloroform in November after testing candidate liquids on himself.

The first systematic treatise

John Snow publishes On the Inhalation of the Vapour of Ether, treating administration as a measurable process.

The first recorded death

A death under chloroform is reported in England, beginning a long argument about the comparative safety of the two agents.

Chloroform used in childbirth at court

The administration of chloroform to Queen Victoria removes much of the remaining social objection to obstetric use.

Local anaesthesia demonstrated

Carl Koller shows that cocaine applied to the surface of the eye produces local insensibility.

Anaesthetic charts introduced

Pulse and respiration begin to be recorded through the course of an operation rather than remembered afterwards.

Spinal anaesthesia reported

August Bier describes the injection of an agent into the spinal fluid to produce insensibility below the level of injection.

The string galvanometer

Willem Einthoven's instrument makes the electrocardiogram practical, though decades pass before it enters routine monitoring.

The human electroencephalogram

Hans Berger publishes recordings of electrical activity from the scalp.

An intravenous induction agent

A short-acting barbiturate enters use, making induction rapid and shifting the balance away from inhalation alone.

Stages of anaesthesia described

Arthur Guedel publishes a graded account of the successive stages observed under ether.

Curare reported in anaesthesia

Muscular relaxation is separated from depth, changing what a given amount of agent has to achieve.

Halothane enters use

A non-flammable halogenated agent designed from first principles replaces much of the older inhalational practice.

Gate control theory published

Melzack and Wall propose a modulating mechanism in the spinal cord, displacing simple specificity accounts.

Pulse oximetry devised

Takuo Aoyagi works out that the pulsatile component of transmitted light can be read as arterial oxygen saturation.

Protein targets proposed

Experiments on a soluble protein show anaesthetic inhibition without any lipid membrane present.