Mass-to-charge ratio refers to the molecular or atomic mass number and "z" to the charge number of the ion; however, the quantity of "m"/"z" is dimensionless by definition. An ion of 100 atomic mass units ("m" = 100) carrying two charges ("z" = 2) will be observed at "m"/"z" = 50. In the 19th century, the mass-to-charge ratios of some ions were measured by electrochemical methods. In 1897, the mass-to-charge ratio of the electron was first measured by J. J. Thomson. By doing this, he showed that the electron was in fact a particle with a mass and a charge, and that
Alan (given name) what is today Brittany, France. An early figure who bore the name was St Alan, a 5th-century bishop of Quimper. This saint became a cult figure in the Brittany during the Middle Ages. Another early bearer of the name was St Alan, a 6th-century Cornish saint, who has a church dedicated to his memory in Cornwall (for example see St Allen, a civil parish in Cornwall named after this saint). Today the use of the given name (and its variants) is due to its popularity among the Bretons who imported the name to England, to Cornwall, and later to Ireland.