Lynn,
The piece on horn dying with the photos was my work.
In another thread there was a suggestion that you bury the horn in manure.
This came out of an old wool dyeing process.
If you dye the horn with copper sulfate you get one color. If you dye with copper acetate you get another color. Copper acetate is more soluble that copper sulfate so you get more copper metal into the horn with the copper acetate.
Think of copper trim, gutters and downspouts on churches.
If you subject the copper dyed article to sulfur-bearing gases,sulfur dioxide or hydrogen sulfide it will attach to the copper and give yet another color.
I don't know how you would ever get rid of the manure smell in a horn. I think the deal was that you put the wool or horn in a confined area where the sulfur-bearning gases given off by the decomposing manure would then act on the copper in the horn.
When I first experimented with the copper dye on horn I did one in the lab at work. After dyeing I simply heaved the horn int a 200 degree oven to convert the copper to the water-insoluble state and dry the horn. Next day I pulled the horn out of the oven. It looked as ifit had been formed out of thin sheet copper. It was a copper color. So it was back to the archaic technology book. Then earned that the correct way to do it was to steam the horn, or wool, after it came out of the bath.
The thing about steaming versus simple drying was that ith steam you convert the copper to the water-insoluble form with no migration of the dye solution to the surface of the horn until after the copper had converted to the water-insoluble form. Otherwise you get a good bit of the dye migrating to the surface of the horn when you really want it chemically locked into the horn.
Anyway. It took almost two years for that oven dried horn to change from the metallic copper color to the desired green color.
In dyeing horns you should understand that a clear, colorless horn is somewhat porous and will pick up a lot of dye solution. Horn that is colored, especially white, will pick up very little dye solution. To understand this you must look at the horn's micro-structure under a strong microscope. The horn is fiberous in nature in that it is comprised of irs that are bonded together. If the hairs are very tightly bonded together you get a hard and somewhat brittle horn. If the hairs are only loosely bonded together you get a slightly soft porous horn. Under the microscope I noted that with a white "scrimshaw quallity" horn the pigment is deposited on the surfaces of the hairs and really cuts down on any free space between the hairs and this prevents the dye solution from penetrating into the horn.
The photos shown in the piece on the web were from the last Gunmaker's Fair I set up for. On that Sunday afternoon there was a line at my table formed by those who were to get the horns as gifts. People who had encouraged me on the project which had actually taken several years to do. I had been working out of industrial chemistry books that dated to the early 1900's. There were times when I just wanted to walk away from the work but did not.