This section of the book is from the "Household Companion: The Family Doctor" book
This is a solution of gun-cotton in ether. When it is painted upon
any surface the ether evaporates leaving a thin cottony film. Flexible collodion, made a little differently, is less apt to shrink to gether in drying. It is a convenient article to cover a part whose skin is broken or ulcerated, as sore nipples, cracked lips, etc.