The Compleat Alchemist a 'Fantasy Role playing Game Supplement' as the subtitle has it, was written by Stephan Sechi and Steven Cordovano and published in 1983 by Bard Games- a company sent up by Sechi and Cordovano in order to market the book. There were two printings by Bard games. The first, and more hard to find, has a white cover, and the second and less rare one has a dark pink, burgundy colour.
The idea was to create a series of generic supplements for fantasy role playing games. By the time Bard Games folded in 1990 they had three 'Compleat...' books; The Compleat Alchemist, The Compleat Spell-Caster; and the Compleat Adventurer. Sechi was the driving force behind these and the later Atlantis rpg also known as Arcanum. He is better known perhaps as the author of Talisanta.
The Complete Alchemist is a 45 page perfect bound book, simply produced, with artwork and layout typical of the time. Some of the drawings by illustrator Joe Bouza are in fact very good. Curiously, the layout (created on an electric typewriter it appears) changes in font and size throughout the book. This is possibly to differentiate rules from general information, but I personally find myself squinting at some of it. This isn't atypical, lots of Judges Guild work of the period is the same tiny fonts and Dave Hargrave's Arduin Grimoires often require a magnifying glass to read!
The content is pretty thorough. There's a section on how to roll up your Alchemist, the minimum stats he might need etc. As the book is designed to be 'generic', there are suggestions for creating Alchemists within 3d6 mechanics, percentile based mechanics and d20 games too. Some reviewers found this confusing at the time, but I think Sechi and Cordovano did quite a good job, if you read it carefully. The class itself has several specialist skills in assessing materials, mixing and preparing ingredients, plant and mineral identification skills etc, all of which increase as the character levels up. Alchemists it seems are also master linguists and decoders of ancient texts, so that they end up with the skills of magic users and clerics in reading magical languages and so on.
The bulk of the book describes these skills, and many more, in terms of levels as if they were spells. And then goes on the describe the potions, powders, mysterious substances and semi magical items an alchemist can make. There are extensive lists of herbs, precious and semi precious stones, rare earths (very important) plants and metals, together with their powers and properties. It's all quite clear and well done, extensive without being over done. Much of this section could easily be lifted and used in any other game even ones without Alchemists.
The question remains however, how a player would get on in a typical fantasy adventure. Eventually, he becomes a sort of walking arsenal of explosive, poisonous and mysterious weapons. But I think would be tied to his laboratory much more than other classes would be to their base of operations. There are notes for travelling cases of experimental equipment and mineral testing kits and so forth. But even so, having an alchemist in the party is definitely going to require some henchmen to lug around his kit!
Having such class as an NCP to support your crack team of murder hobos would be a great thing to have however and adventure hooks based around finding your boffin some rare earth from beyond the Misty Mountains would have a real point. Especially if he then made your party some brilliant gas bomb or some such to help crack the next dungeon.
Other versions of the alchemist class have of course been created. But if you are running a game that currently doesn't have such a class, this book would very easily be an excellent choice.
When Bard games folded, WoTC bought the licence and published a version of the Compleat Alchemist in 1993.