Facts and Formulae Clippings from a 1936 London Periodical
These were gifted, not bought. Someone has very carefully cut a couple of hundred little facts and formulae clippings from a magazine put out around 1936 (2nd September 1936 is mentioned on the second Index Card), and pasted them onto 3.5x5 inch cards and filed them according to subject matter. There are general photographic knowledge tidbits as well as formula for various situations, whether it be fine grain negative developers, print reduction formulas, toners or bleaches. There's a listing of the main chemicals used, along with their uses, storage life, the safest strength that can be made in solution and if any alternative chemicals can be used in their place. Amongst all of the developers, stop baths, fixers, print and negative reducers and intensifiers there are the 'Maker's Formulae' from Agfa, Barnet, Gavaert, Ilford, Kodak, Voigtländer, and Zeiss Ikon, and others.
As the photos below will attest, I'm an awful photographer, so it's just as well I'll have these to scan, OCR and catalogue for entertainment over the next thirty years!