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 Medical Society Royal Medical Society The Royal Medical Society (RMS) is a society run by students at the University of Edinburgh Medical School, Scotland. It claims to be the oldest medical society in the United Kingdom although this claim is also made by the earlier London-based Society of Apothecaries (1617) which is permitted to award medical degrees. The current President of the 282d session is fourth year medical student, Ms Hannah Patterson. The RMS is a professional society engaged in the advancement of medical knowledge and provision of assistance to medical students and professionals. In 1737 it was established as 'the Medical