The colouring matter, which is soluble in alcohol and ether-alcohol, but not in pure ether, is precipitated by lead-acetate, decolourised by reducing agents, and recovers its red colour on exposure to the air, just like litmus and the red colour of wine (De Luca and Ubaldini, in Watfs' Did., vi., ist Supp., 608.)."
A substance with a distinctive red colour that is soluble in alcohol-ether mixtures but not pure ether changes its state when treated with lead acetate, reduced by agents to remove the colour, and regains its reddish hue upon exposure to air, similar to litmus and the colour of wine (De Luca and Ubaldini, in Watfs' Did., vi., ist Supp., 608.).