Rutherford had noticed, while still in Montreal, that some alpha particles passing through thin sheets of metal were slightly deflected, causing fuzziness on a photographic plate. As instructed by Rutherford he fired beams of alpha particles at some gold foil and by the tiny flashes of light when they struck a zinc sulphide screen discovered that a few "were deflected through quite an appreciable angle".
Rutherford was born in 1871, in Spring Grove, New Zealand.
Descended from Scottish emigrants, it was from this scattered rural community on the north coast of the South Island that Rutherford's aptitude for science and maths led in 1895 to a coveted place at Cambridge.
Aged just 27, in 1898, he was appointed professor of physics at Mc Gill University in Montreal, Canada.
Among his successes over the next nine years the most important was the discovery, with his collaborator Frederick Soddy, that radioactivity was the transformation of one element into another due to the emission of an alpha or beta particle.
"Going down to the refectory for lunch, I would hear the loud, friendly voice rolling up the corridor." At the time Rutherford was busy using the alpha particle to probe and unlock the secrets of the atom. It was a question that Rutherford and his German colleague Hans Geiger answered.
It was a helium ion; that is, a helium atom that had been stripped of its two electrons.