Grimrock

I must be missing something really obvious but i cant make/cast a spell . Can somebody give me a step by step guide on what to do.
I have the mixing bowl ( mortar and pestle ) and when i right click onto it i see 6 symbols that are greyed out , their is also a oblong box under these symbols.
I have scrolls that show you what you need , i read that after you have looked at the scrolls you dont need to keep them.
I have the ingredients for the spells but cant work out what moves i need to do to make them.

Ingredients are used for potions, not magic.
Spell casting requires energy, the skill requirements and gesture for the spell you want to cast and a character with either glowing hands or a usable wand or orb.

The ingredients have to be in the inventory of the champion using the mortar and pestle.

thanks for your replies