Does anyone know what the golden letters surrounding the potions class mean/say?

I can see only a part of these letters. And it looks like 'potatium carbonata'. I'm not sure, especially the endings, but it could be something like 'you are drinking' for the first word and the secondo could be standing for the element 'C' like carbon/carbonium. But I don't think that's very helpful...I think here we need a latinum professor.