litmase

Updated: May 28, 2025

Let me add, that having made divers Tryals with that Blew substance, which in Painters shops is call'd Litmase, we have sometimes taken Pleasure to observe, that being dissolv'd in a due proportion of fair Water, the Solution either oppos'd to the Light, or dropp'd upon White paper, did appear of a deep Colour betwixt Crimson and Purple; and yet that being spread very thin on the Paper and suffer'd to dry on there, the Paper was wont to appear Stain'd of a Fine Blew.

Robert Boyle - Experiments and Considerations Touching Colours (1664)