Various, Notes and Queries, Number 168, January 15…
“ Having occasion to remove a slate from the side of my roof, to make an opening for my camera, I thought of a sheet of India rubber to supply the place of the slate, and thus obtain a flexible waterproof covering to exclude the wet, and to open and shut at pleasure. This succeeded admirably, but I found that I had also obtained a deep rich yellow window, which perfectly lighted a large closet, previously quite dark, and in which for the last ten days I have excited and developed the most sensitive iodized collodion on glass. ”
