This will soon become of a deep red color.

For use, fill your small bottle, having a quill in the cork, with alcohol, and add a few drops of the above, or enough to change it to a bright orange or saffron color.
A Substitute for the Hyposulphite Solution .-- M.

DAGUERRE recommends the use of a solution of salt water for removing the coating off the plate.
I found this of some service at one time during my travels.

My hyposulphite bottle got broke and its contents lost, so as only to leave enough for preparing gilding.

I resorted to the use of salt solution, and found it to answer well.