If you have the proper skill, you can identify potions and elixirs you may find. This process must be role-played accordingly, by scrutinizing the bottle, holding it up to the light, shaking the contents, and otherwise investigating the mysterious liquid.
After three seconds (which out-of-game is usually spent reading the tag on the item), a character with either Healing Arts or Herbal Lore can tell whether a liquid is a magical potion or an elixir and after an uninterrupted minute of this role-playing, can determine which magical potion it is.
Example, Darlissa the healer has three unidentified vials of liquid before her. One is a Cure Wounds potion, one is an alchemical Berserk elixir, and one is orc blood. She spends three seconds examining each one. After nine seconds (three for each), she can tell that one is a magical potion (the Cure Wounds vial). She also knows that the other two are not magical potions, but has no idea whether the other two are alchemical or something else. She then spends a minute examining the magical potion, at the conclusion of which she is able to determine that it is a Cure Wounds potion.
This skill cannot be used to identify blood types, detect the presence of poison in the bloodstream, identify a type of monster or a race from a blood sample, or otherwise do modern chemical observations.
Some potions you find will already be labeled. Others will be unidentified. These are usually marked as such but will say out-of-game whether the unidentified item is magical or alchemical. Once a character with this skill spends the minute to identify the potion, the “unidentified” tag may then be removed, revealing the real tag below.