Collodion is a syrupy solution made from nitrocellulose dissolved in a mixture of ether and alcohol. It was first developed in the mid-19th century and is primarily used in photography and medicine. In photography, it served as a key component in the wet plate collodion process, allowing for the creation of detailed images on glass plates. In medicine, collodion is used as a topical dressing for wounds. When applied, it dries to form a flexible, protective film that helps to keep the area clean and promotes healing. Its versatility makes it valuable in both artistic and medical fields.