Hans Zinsser taught bacteriology and immunology at the universities of Stanford and Columbia before going on to teach at the Harvard University Medical School. As well as researching extensively into cholera, allergies and rheumatic fever, he was a pioneer in isolating the micro-organism that causes a form of typhus. To Zinsser, scientific research was high adventure and the investigation of infectious disease, a field of battle. He died in 1940.

Sir Peter Medawar shared the Nobel Prize for Medicine in 1960, for work which helped pave the way for transplant surgery, and was recognized later in life as a scientific philosopher and writer. He died in 1987.

Harry Overstreet was an American lecturer, and popular author on modern psychology and sociology. He died in 1970.

Gayelord Hauser was at one point labelled a quack by the medical profession and the food industry, but continued as a master dietician and health consultant to Hollywood stars. He died in 1984.