Description: Ionization chamber.

Caption: Rutherford was a pioneering nuclear physicist, who to his consternation, won the Nobel prize for Chemistry in 1908! This apparatus is a copy of the instrument he used to "split the atom" a feat that al;tered human history more profoundly than any other scientic discovery before or since.

Introduction: This is a replica of apparatus designed at Manchester in 1919 by Professor Ernest Rutherford in his discovery of the transmutation of nitrogen into hydrogen by high energy alpha particles. Apparatus of this kind was also used by him and his assistant James Chadwick, in the Cavendish Laboratories at Cambridge, during their investigations into the disintegration of light elements by alpha particles.

Background: In use the apparatus was purged with dried air and the source, radium 226, was fixed to the end of a piston in the body tube of the apparatus. The target specimen was placed in a copper slide directly in front of the source. The resultant emissions then passed through a calibrated mica sheet held in a slide at the open end of the tube and impinged on a zinc sulphide screen which fluoresced when a particle of heavy hydrogen struck it.

Historical Context: Design - When: circa 1919 - Who: Rutherford, Ernest, 1st Baron Rutherford of Nelson (1871-1937) Pioneering nuclear physicist, of Scottish ancestry born in New Zealand

Historical Context: Design, Cavendish Laboratory - Where: Cambridge, England

Historical Context: Manufacture - When: circa 1925 - Where: Unknown, the instrument is unsigned

Historical Context: Used in lecture demonstrations - When: circa 1930 - Where: Department of Physics and Astronomy, formally known as the Department of Natural Philosophy - Who: Department of Physics and Astronomy formerly the Department of Natural Philosophy, University of Glasgow