Electric light be made with a screw-thread base, two metal pins, two metal caps or a bayonet cap. The three main categories of electric lights are incandescent lamps, which produce light by a filament heated white-hot by electric current, gas-discharge lamps, which produce light by means of an electric arc through a gas, and LED lamps, which produce light by a flow of electrons across a band gap in a semiconductor. Before electric lighting became common in the early 20th century, people used candles, gas lights, oil lamps, and fires. Cornish chemist Humphry Davy developed the first incandescent light in 1802, followed
Royal Society of Biology society, previously called the Society of Biology, was granted permission to become the "Royal Society of Biology". The society is also a registered charity. The first president of the society was Nancy Rothwell (University of Manchester) and the current president is Julia Goodfellow. The society has six Special Interest Groups: the Animal Science Group, UK Biology Competitions, Natural Capital Initiative, the UK Plant Sciences Federation, Biology Education Research Group and Heads of University Biosciences. The Royal Society of Biology supports university students and early-career researchers with careers advice, travel grants and Life Sciences Careers Conferences. In 2012 it developed a