Bert was born in France in 1833. He studied physiology at the Ecole Polytechnique at Paris. After graduation as doctor of medicine in 1863, and doctor of science in 1866, he was appointed professor of physiology successively at Bordeaux and the Sorbonne. He studied the effects of altitude on hot air balloonists and was also interested in what happened to blood gasses when people were exposed to greater than normal pressures. This led him to study divers and the phenomenon of decompression sickness.
From his studies, he determined that the high external pressures the divers experienced forced large quantities of nitrogen gas from the atmosphere to dissolve in their blood. When the external pressure was relieved as the diver surfaced, this nitrogen came out of the blood stream in the form of bubbles. These bubbles blocked the capillaries (the smallest blood vessels) causing the bends.
He compiled his findings into a book, La Pression baromeetrique: recherches de physiologic expeerimentale. In 1943 the book was published in English. Bert's work provided a foundation for the development of diving and aviation medicine. Later it served as a starting point in early aerospace research on the effects of changes in pressure on astronauts.