In this chapter, we get a brief description of the holy city of the pill-tower. It's a place where alchemists gather to test their abilities. In other words, it's where they're supposed to gather their potions. In this case, the potion-tower is the place where the elite of the alchemist's clan gather to discuss the latest developments in the field of medicine. We're not exactly sure what this means, but we're guessing that it means that the top tier of the clan has to be an alchemist or a divinarian. So, basically, you're going to have to be either a "tier seven alchemist" or a "dou venerate" .