Hydrogen Cyanide 1782

The production of hydrogen cyanide (hydrocyanic acid) out of the sulfuric acid and Berlin-blue was discovered by Swedish chemist Carl Wilhelm Scheele in 1782. French chemist and physicist Joseph Louis Gay-Lussac prepared pure liquefied hydrogen cyanide in 1811.

Chlorine 1774

Chlorine was discovered in 1774 by Carl Wilhelm Scheele, a German / Swedish pharmaceutical chemist. He also discovered nitrogen, oxygen, barium, manganese, and wolfram, not forgetting organic acids like hydrofluoric, hydrocyanic, and arsenic acids.