While buying a present for my wife today, I spied some old bottles - well, more like huge clay jugs - of ink for sale. They were apparently part of the old stock of the shop, and the owner is getting rid of them.
They are marked "Stephens' Blue-Black Writing Fluid", and promise that the liquid will write clear blue and turn black as it dries. Does anyone know anything about this ink? It is not, I think, the "Registrars' ink" that they also made.
I haven't tried opening the jar yet. I assume it is not safe to use in modern pens, but I'd love to know more about it.
Does anyone know more?