Input (grade 13): In 1659, Johann Rudolf Glauber fused a mixture of the mineral pyrolusite and potassium carbonate to obtain a material that, when dissolved in water, gave a green solution (potassium manganate) which slowly shifted to violet and then finally red.
Output (grade 10): In 1659 a German chemist, J.R. Glauber, melted a mixture of the mineral pyrolusite and potassium carbonate to obtain a material that made a green solution (potassium manganate) when dissolved in water. It slowly changed color to violet (potassium permanganate) and then finally red.