Today, Jan Ingenhousz's 287th birthday is celebrated by Google Doodle. Ingenhousz was a brilliant Dutch physician, biologist and chemist who discovered the processes of photosynthesis and plant cellular respiration. Ingenhousz, working on Joseph Priestley's discovery that plants absorb gases, found that plants gave off oxygen in the presence of light. This led Ingenhousz to reason that at least part of the mass of plants came from the air. Also, Ingenhousz found that plants could renew air, i.e. restore oxygen, in the course of a few hours through respiration. In 1779, Ingenhousz publish...