Chlorine: Manganese Dioxide Heated with Hydrochloric Acid (Scheele)

Chlorine as Scheele first made it in 1774, and the readiest laboratory way in Thorpe's Dictionary (1912): heat manganese dioxide with hydrochloric acid. MnO2 + 4HCl = Cl2 + MnCl2 + 2H2O. Chlorine cannot be breathed: it rapidly attacks the membranes. Fume hood, respirator. The picture: our diagram.