It is important not to confuse IMC with IFR (instrument flight rules) â IMC describes the actual weather conditions, while IFR describes the rules under which the aircraft is flying. Aircraft can (and often do) fly IFR in clear weather, for operational reasons or when flying in airspace where flight under VFR is not permitted; indeed by far the majority of commercial flights are operated solely under IFR.
Norbert Rillieux. Norbert Rillieux (1806-1894) was the inventor of the multiple-effect vacuum evaporator, which revolutionized the processing of sugar. He gained recognition as one of the prime architects of the modern sugar industry.
A pure, but tiny, amount of the metal was isolated in 1808 by Humphry Davy by the electrolysis of magnesium oxide. However, it was the French scientist, Antoine-Alexandre-Brutus Bussy who made a sizeable amount of the metal in 1831 by reacting magnesium chloride with potassium, and he then studied its properties.