298 years ago today, on August 19, 1727 (July 3, 1727 lunar calendar), Hales observed that heating coal in a sealed container would produce "flammable gases". On August 19, 1727, Hales, an English priest, botanist, and physiologist, pointed out in his book "Plant Statics" that heating coal in a sealed container would produce "flammable gases". In fact, Clayton discovered this phenomenon as early as around 1684. It was only made public in 1739. Clayton heated coal and observed that "the soul of coal can be lit by a candle". Converting coal into gas and then using it as an energy source is a major advance in the way humans use coal, and it brings great convenience to people. Discovery of gas