The table of developers for wet plate collodion process

Ferrous Sulphate
- major developing agent
- reduces the silver nitrate on to metallic silver
- is not permanent, by air oxidizes on to ferric sulphate (brown color), this process continues in developer if contains only acetic acid

Copper Sulphate
- accelerates developing
- increases coverage
- enhances cleanliness of developing

Potassium Nitrate
- for better of white on the plate

Silver Nitrate
- for better metallic silver on the plate

Acetic Acid
- prevents formation of ferric hydroxide
- know not prevent oxidation of Ferrous Sulphate therefore old developers with acetic acid can have a dark color
- gives a warm tone

Nitric Acid
- prevents formation of ferric hydroxide
- stabilizes of Ferrous Sulphate, the oxidation slows down considerably and therefore have developers with inorganic acid longer of life time
- gives a cool tone

Sulfuric Acid
- prevents formation of ferric hydroxide
- stabilizes of Ferrous Sulphate, the oxidation slows down considerably and therefore have developers with inorganic acid longer of life time
- gives a cool tone
- have a less oxidative influences

Ethanol
- ensures adhesion of developer to the collodion layer