Benefit: The alchemist gains the ability to create a cognatogen, a mutagen-like mixture that heightens one mental ability score at the expense of a physical ability score. If the cognatogen enhances his Intelligence, it applies a penalty to his Strength. If it enhances his Wisdom, it applies a penalty to his Dexterity. If it enhances his Charisma, it applies a penalty to his Constitution. Otherwise, this ability works just like the mutagen ability (including the natural armor bonus). Anytime the alchemist would prepare a mutagen, he may instead prepare a cognatogen. All limitations of mutagens apply to cognatogens as if they were the same substance—an alchemist can only maintain one mutagen or cognatogen at a time, a cognatogen that is not in an alchemist’s possession becomes inert, drinking a cognatogen makes a non-alchemist sick, and so on. When the effect of the cognatogen ends, the alchemist takes 2 points of ability damage to the ability score penalized by the cognatogen. The infuse mutagen discovery and the persistent mutagen class ability apply to cognatogens.