The court stated, "Although the specification does say that the ‘polymers obtained in the above examples were useful’ because they had great thermal stability and resisted various fluids, it is not apparent from the fact of the specification how utility could in fact be achieved. If the specification had indicated a particular use for the film, and if the question before us was whether the language used was sufficient to explain this use to one skilled in the art, then testimony of experts might well have been received."