Why are the royal signals nicknamed scaleybacks?

The Royal Corps of Signals nickname 'Scalie/Scaley backs' came about during the First World War. It comes from the battery acid burns that were found on the back of the Engineers who carried batteries up to the front line trenches for use with the radiOS that often leaked the acid down their backs. Wireless communications were used in various campaigns including France, Flanders, Salonika, Palestine and Mesopotamia.