Tristan Tanner from the Bogeyman's Cave asked for "a table of odd potions found in an alchemist's basement" as his Santicorn present. Hi Tristan! I tried to give the potions some flavour of "real" alchemy. Hope you like them.
1. Vitreous, honey-coloured liquid, smells faintly of burning. Failed attempt at an elixir of life. Pour this potion on any surface and living, immortal cancers will grow there, blooming like mandelbulbs. Stone grows stone cancers, flesh grows flesh, and so on. One flask of the potion is enough to fill a 10' wide corridor with growth. Drinking this potion will turn the imbiber into a calcinated lump of immortal flesh.
2. Hissing, bubbling grey liquid. Failed attempt at universal solvent. When this potion is poured over an object, the object's borders become blurry and diffuse, allowing it to pass through other solid objects. As the effect fades, the object solidifies, leaving it fused with whatever it was stuck inside of. Chimeras can be created in this way. Multiple sentient beings fused together will form a single mind with all of their memories and personalities blended together.
3. Inky black liquid, greasy, with an eerie blue-purple depth to its colour. Failed attempt to promote the alchemical process of nigredo (putrefaction). Applied to living matter, it causes accelerated aging. Applied to dead matter, it causes rapid decomposition, turning corpses into dust within less than a minute. Drinking it causes a violent purge: make a save vs. poison, on a failure age 3d10 years, but either way you will vomit up all diseases and curses that currently afflict you.
4. Translucent white liquid, glows faintly, consistency of melted butter. Failed attempt to promote the alchemical process of albedo (separation into opposites). Pouring this potion over an object divides it into two phantom copies, one of which only exists in light, the other only in darkness. Drinking this potion causes the imbiber to see their animus or anima: a shadowy doppelganger with reversed gender. Nobody else can see the animus. Make a reaction roll to see if the animus is friendly or hostile. If it is charmed or defeated in battle, it will answer one question. It knows everything that is known by any creature of the same species.
5. Yellow liquid, glitters like gold when held up to the light. Failed attempt to promote the alchemical process of xanthosis (transmutation). Pour this liquid over lead and it will turn into an unstable form of gold. 1000gp worth of gold can be created with one potion. The gold reacts to sunlight, decaying into fractal honeycombs and then bursting into flame. Drinking this potion causes the subject to defecate 1000gp worth of unstable gold over the course of seven days.
6. Red liquid, consistency of oobleck. Failed attempt to promote the alchemical process of rubedo (perfection). Pour this liquid over any object and it will turn into the platonic ideal of that object. Such objects are too real for the human brain to be comfortable with them. All rolls are at -2 while in the presence of such an object. If a character drinks this potion it will make their soul perfect. At first there will be little noticeable change, except that they seem highly charismatic, graceful, enlightened and rational. Gradually they will begin to feel disgust at the flawed natures of all other humans. They will feel it is a moral duty to treat others to the same perfection that they have experienced. To this end they will create more of the red potion (which they instinctively know how to make) and administer it to others by any means necessary - persuasion, subterfuge or force. They will not stop until everyone and everything is perfect.