There are a lot of books covering historical subjects on the web. Their contents usually won't show up in a general web search though. I have learned a lot abou

There are a lot of books covering historical subjects on the web. Their contents usually won't show up in a general web search though. I have learned a lot about the past from old books. Google Books, the HathiTrust, and archive.org are useful here. Newer books are often available on Library Genesis. As an example: have you ever wondered about the state of toxicology in the late Victorian era? What poisons were known, what poisons were detectable (and how), and other nuts-and-bolts details of a certain kind of murder mystery? This information is hard to find in modern web pages -- particularly if you don't know enough to tell who is a trustworthy guide to the past. But a HathiTrust search does the job easily. Use the "advanced full text search" form. Search for the word poisons. Restrict results to English language documents in the years 1880-1900. You'll get a wealth of books back, like this illustrated 1885 text: "Micro-chemistry of poisons : including their physiological, pathological, and legal relations; with an appendix on the detection and microscopic determination of blood: adapted to the use of the medical jurist, physician, and general chemist" https://babel.hathitrust.org/cgi/pt?id=nnc2.ark:/13960/t9d51ct7s&view=1up&seq=7 https://babel.hathitrust.org/cgi/pt?id=nnc2.ark:/13960/t9d51... Or from 1883: "Indian snake poisons, their nature and effects." https://babel.hathitrust.org/cgi/pt?id=coo.31924003195769&view=1up&seq=5 https://babel.hathitrust.org/cgi/pt?id=coo.31924003195769&vi... 1899: "Practical materia medica for nurses, with an appendix containing poisons and their antidotes" https://babel.hathitrust.org/cgi/pt?id=loc.ark:/13960/t0pr8z47c&view=1up&seq=5 https://babel.hathitrust.org/cgi/pt?id=loc.ark:/13960/t0pr8z...