Mims is a good resource, but very dry reading. The Oz drug guide has cute historical notes. Ie. page 111 of the 1998 4th Ed. States that "Cephalosporins were derived from a fungus found near a sewer outlet off the coast of Sardina, Italy." Fungi are enemies of bacteria because they compete for the same space.
I bet the Drs don't highlight where they found their Txs from