Austrian psychologist Sigmund Freud publishes The Psychopathology of Everyday Life

German immunologist August von Wasserman develops a diagnostic test to reveal the presence of the syphilis spirochaete in the blood

Belgian physiologists Jules Bordet and Octave Gengou identify Bacillus pertussis, the bacterium causing whooping cough

A pediatrician in Vienna, Clemens von Pirquet, describes a condition for which he coins the term 'allergy'

The German neuropathologist Alois Alzheimer identifies physical symptoms in the brain of a dead woman who had presenile dementia

Austrian scientist Clemens von Pirquet discovers a diagnostic test to identify tuberculosis in a patient

French biologist Charles Nicolle discovers that epidemic typhus is transmitted by the body louse

Chicago cardiologist James Herrick publishes the first account of the cells causing sickle-cell anaemia

Alfred Adler ends his association breaks with Sigmund Freud and forms his own school of psychology

Carl Jung breaks with Freud and introduces the concept of the collective unconscious

Typhoid-carrier Mary Mallon is detained in New York after leaving a trail of destruction

A typhus epidemic sweeps through Serbia, severely weakening the nation's armed forces

New Zealand surgeon Harold Gillies sets up a plastic surgery unit at Aldershot, a British military base

A world-wide pandemic of influenza breaks out, and within the space of a year kills 30 million people

New Zealand surgeon Harold Gillies publishes a pioneering text book, Plastic Surgery of the Face

Alfred Adler, in Vienna, opens the first of many child-guidance clinics

Canadian physiologists Frederick Banting and Charles Best isolate insulin from the pancreas for the treatment of diabetes

Sigmund Freud proposes a new interpretation of the mind in his book The Ego and the Id

English psychologist Henry Havelock Ellis completes a thirty-year project, his 7-volume Studies in the Psychology of Sex

An Aerial Medical Service is launched in Queensland, Australia, subsequently becoming the Flying Doctor Service

Scottish bacteriologist Alexander Fleming accidentally discovers a mould that selectively kills bacteria, and calls it penicillin

A deeply flawed experiment with African American syphilis patients is launched in Tuskegee, Alabama

British biochemist Max Perutz begins the analysis of haemoglobin

Lord Nuffield donates to Commonwealth hospitals 'iron lungs', built at his Morris Oxford factory,

British biologists Ernst Chain and Howard Florey develop penicillin as a safe and useful antibacterial drug