Mental acuity potion

"Albert Bellchant? That's Astor's son! Oh dear, it isn't exactly glowing with praise. He's failing Transfiguration, Charms, and Herbology! Not exactly living up to the family name, is he? Wait, Edgar! Wasn't that bottle we found in Bilius's apron labelled 'for mental acuity'? What if Bilius was blackmailed into brewing a potion for Astor's son?"

- Mathilda Grimblehawk

The mental acuity potion was a potion used to improve the focus, memory, and concentration of the drinker. This potion is made from "all kinds of restricted ingredients", making it illegal in Britain.

After receiving a letter from Hogwarts School informing him that his son Albert was failing Transfiguration, Charms, and Herbology, Astor Bellchant blackmailed Bilius Finbok, with whom he had attended Hogwarts, into brewing an illegal mental acuity potion. Ultimately, Finbok was injured through his use of illegal materials from magical beasts in the brewing of potions.