1730-1799

Dutch Plant Physiologist and Physician

Jan Ingenhousz is best known for his discovery of photosynthesis, the process by which green plants absorb carbon dioxide in the presence of sunlight and release oxygen. Through an ingenious series of experiments, Ingenhousz proved that plant leaves need sunlight rather than heat in order to produce oxygen. He also discovered that plant leaves reverse this process in the dark and release carbon dioxide. Ingenhousz's remarkable observations on plant physiology and photosynthesis were published as Experiments Upon Vegetables, Discovering Their Great Power of Purifying the Common Air in Sunshine, and of Injuring It in the Shade and at Night (1779).

Ingenhousz was born in the Netherlands in 1730. He studied medicine, chemistry, and physics at the universities of Louvain and Leiden. In 1765 he visited London and established a successful medical practice there. He became well known as an early practitioner of inoculation...