A drop or two of the prussiate solution then gives a brown colour, even if but traces of copper are present.
As soon as the prussiate appears to be decomposed and dissipated the articles are plunged into cold water.
A beautiful brown can be obtained by next putting the goods through a solution of prussiate of potash.
Might you not have used potassium cyanide or prussiate of potash?
Ecru: Continue the foregoing operation for blue by passing the goods through a solution of prussiate of potash.
The piece being heated may then, if small, be dipped in the prussiate of potash, or if large have the same spread upon it.
In default of prussiate of potash, animal or even vegetable charcoal may be used, but the latter is a very imperfect substitute.
A mordant of blue vitriol is commonly first given, followed by a bath of prussiate of potash.
He carefully stopped the bottle containing the remainder of the prussiate of potassium, and took that also.
A very good black is the prussiate or steam aniline black whose cheapness should recommend it.
