QuoteWe used to make fermented mare's milk yoghurt, custom-made vaccines (using your own bacteria) and all kinds of cranky and otherwise unibtainable stuff as well as doing all kinds of routine bacteriology, phenotyping, forensic work for the police and so onf. Colloidal gold (in particular) was a regular seller peddled as a treatment for arthritis. This kind of laboratory is now pretty much a vanished world.
As it should be. Colloidal gold was, at one time, legitimate (but toxic) therapy for people afflicted with really horrible rheumatoid arthritis. Now, it's been replaced by monoclonal antibodies, methotrexate, and other immune suppressants. The rest of what you mentioned was and still is quackery, especially colloidal silver which is quite dangerous. https://en.wikipedia.org/wiki/Argyria