  The identification of the subset of factors (i)–(iii) that constitute the ruling is not always a straightforward task: this has to be determined from construing the judgment as a whole in the context of the area of law with which it deals. In particular it can be difficult to ascertain the appropriate level of abstraction of the descriptions of factors (i)–(iii). A person is made ill by drinking an opaque bottle of ginger beer containing a decomposing  snail.[5]   The manufacturer of the bottle is held to be liable to the person made ill, despite the absence of any contract between her and the manufacturer. What is the key characterisation of the vehicle of harm on these facts?  The bottle of ginger beer is a beverage, but it is also a consumable, an article for human use and something capable of causing injury if negligently produced. (See further Stone 1985, 125). Generally the judgment needs to be read as a whole to determine the appropriate level: in particular the court's reasoning will tend to support one level of generality over another. In some cases, however, the level of generality will not be clear and it will not be possible to give a very precise account of the ruling. In other cases the category may be incompletely characterised: there will be examples of items falling within the category but no general characterisation of it (see Levenbook 2000, 201–11).