Joseph John Thomson (1856-1940)
British physicist born in Manchester in 1856 and died in Cambridge in 1940.
Graduated in Cambridge in 1884, where he was Professor of Experimental Physics and director of the Cavendish Laboratory until his retirement in 1919. Measured the specific charge of the electron for the first time (1897) and it showed that the thermoinic effect is due to the presence of electrons. Through the action of electric and magnetic fields on a beam of neon ions, Thomsom verified in 1913 the existence of isotopes in non-radioactive elements, proposing the "parable method". Was awarded the Nobel prize of Physics in 1906 for theoretical and experimental research of electricity effects on gases.