The articles below deal with general issues of photographic chemistry either providing a broad overview of the subject or covering issues that are not covered elsewhere in the Library. For example, John Towler's look at "Printing by Development (Chapter 34) and M. Guinet's On the Tinctorial Properties of Albumen give interesting insight into aspects of 19th Century research into photographic chemistry. One of the more amusing commentaries in the library is contributed by Thomas Barber, 1859 where he cautions against the fabrication of pseudo-scientific terminology unless one has "good authority for so doing, lest we should some fine day derisively draw upon ourselves another new term-"photo chemists"--ironic in light of the fact that the term "photo chemist" was embraced and legitimized by the end of the century.