The word emulsion comes from the Latin mulgeo, mulgere to milk, [specify] as milk is an emulsion of fat and water, along with other components. Two liquids can form different types of emulsions. As an example, oil and water can form, first, an oil-in-water emulsion, wherein the oil is the dispersed phase, and water is the dispersion medium.
Historians consider the first touch screen to be a capacitive touch screen invented by E.A. Johnson at the Royal Radar Establishment, Malvern, UK, around 1965 - 1967. The inventor published a full description of touch screen technology for air traffic control in an article published in 1968.
Touch screen devices generally come with either resistive or capacitive screens. The type of screen dictates how the device reads user input. In turn, this affects the type of stylus needed to navigate the device, as the stylus must be compatible with the display type. Prior to the 2007 release of the iPhone, most touch screen devices featured resistive screens.