TABLE OF CONTENTS Mass spectrometry had its beginnings in experiments performed over a century ago. Scientists in the late 19th century began conducting experiments within evacuated glass tubes in order to gain some understanding of the nature of electricity.
George Johnstone Stoney was the first to report that electricity has its basis in a particle, or an "atom of electricity" that he referred to as an electron. Stoney measured the charge of the electron in 1894 but it was left to Joseph John (J.J.) Thomson to measure the charge-to-mass ratio ( elm) of the electron and estimate its mass at a thousand times less than that of a hydrogen atom. Thomson had developed an interest in the electron while investigating the passage of electricity through gases in his laboratory in Cambridge. Thomson believed that the stream of rays emitted from a negatively-charged cathode, known as cathode rays, consisted of these particles. He also proposed that the particles (which Thomson preferred to call corpuscles) were one of the bricks from which all atoms were built a controversial theory at the time. Thomson went on to describe his case in the book Corpuscular Theory of Matter published in 1907.
Some time earlier Eugen Goldstein, a scientist in Germany who had given the name to cathode rays and studied them for several decades, discovered that the presence of gases in cathode ray tubes also gave rise to...
