This is a smaller product, but it is totally in line with the Basic-era games. What makes this particular product useful is its flexibility. Produced for Labyrinth Lord it is a solid B/X feeling class. The cover art even invokes the Erol Otus alchemist art from the D&D Expert book. The alchemist can build potions, elixirs, and compounds and use them as magic-user spells. Some examples are given and it has a great old-school feel. In particular, I love the alchemical failure table!
At six pages it is not big, but it makes each page count. I do wish there more examples of spells though.