Complex sentence: French chemist Edmond Frémy (1814--1894) is credited with discovering anhydrous hydrogen fluoride while trying to isolate fluorine, although Carl Wilhelm Scheele prepared hydrofluoric acid in large quantities in 1771, and this acid was known in the glass industry before then.
Split into simpler sentences: French chemist Edmond Frémy (1814--1894) is credited with discovering anhydrous hydrogen fluoride while trying to isolate fluorine. Although Carl Wilhelm Scheele prepared hydrofluoric acid in large quantities in 1771, this acid was known in the glass industry before then.