René Prosper Blondlot (3.07.1849 — 24.11.1930) was a French physicist and a member of the Paris Academy of Sciences (1894). He was born in Nancy, where he graduated from the university and worked (professor from 1896 to 1910).
His research concerned thermodynamics, electromagnetism and optics. In 1891 he developed a method of determining the speed of propagation of electromagnetic waves, obtaining a value of 297600 km/s, and in 1892 a method of transmitting electromagnetic waves along metal wires. He determined the speed of X-rays, found that it coincides with the speed of light and showed that X-rays are electromagnetic waves. He claimed (1903) to have discovered N-rays, which turned out to be a fiction. He carried out experiments with dielectrics moving in electromagnetic fields. He studied the photoelectric effect.