Young's Demonstrative Translation of Scientific Secrets / Or, A Collection of Above 500 Useful Receipts on a Variety of Subjects

by Daniel Young

44. BLUE INK

Take Prussian blue, and oexylic acid, in equal parts, powder finely, and add soft water to bring it to a soft paste, and let it stand for a few days, then add soft water to the desired shade of colour; add a little gum arabic to prevent spreading.