Better Damage Through Alchemistry describes, as its title implies, how to use chemicals to cause damage and injury in d20 systems. It covers a range of chemicals, including varying strengths of acids, bases, chlorine gas, and so on.
All of the chemicals are ones that exist in the real world, although a great many are modern discoveries not known in the middle ages. (Of course, in a world that already has magic, that's not necessarily much of an issue). Each comes with a brief description, and a reasonably detailed summary of the effects of splash damage, ingestion, and inhalation - which reads a little like a Hazard Data Sheet, but with game rules. This information is also summarised in a table at the back of the book.
There are 16 chemicals in total, which is a fair selection. Many of them are quite deadly, but that's likely fair enough - drinking concentrated sulphuric acid isn't going to do anyone any good. The layout of the product is good, including drawings of alchemical symbols (again, real world ones, so far as I can tell), and, aside from the cover, everything is in B&W, and should be easy on a printer.
The book is clearly based heavily on real-world data, but applies it competently to the d20 rules. If you want to add real-world chemicals to your game, with some variety between different kinds, this is a handy resource.
[4 of 5 Stars!]