The fourth column ( Source) gives you hints on where to look for an ingredient - be it monster's body or a plant. Rubedo potions speed up vitality regeneration, Nigredo increases attack, and Albedo contain less toxins.
If all the ingredients in a potion have the same minor substance, the potion gets additional properties. Third column shows minor substances (if present): Albedo (Alb), Nigredo (Nig), Rubedo (Rub). The second column to the left indicates the dominant substance contained in the given ingredient: Rebis (Reb), Vitriol (Vit), Aether (Aet), Quebrith (Que), Hydragenum (Hyd), Vermilion (Ver). For example, use Ghoul Blood instead of White Vinegar when mixing a White Gull or a Swallow. Ingredients that are placed in the potion automatically can then be changed to their cheaper versions, if you will. Remember that you can use the worst kind of alcohol to prepare some White Gull, which itself is a high-quality, strong alcohol. Alcohol you buy for 20 orens lets you mix 3 ingredients, those for 30 orens - 4 ingredients, and those for 50 orens - 5 ingredients. Its quality is described by the number of ingredients you can mix it with.
The alchemy base is always a kind of strong alcohol. Alchemy rules are quite simple, but you should remember a few things. If you have the necessary base and ingredients to mix a potion, just click its name on the recipe list, and then click " Mix".