premise: Once Susan had told him that if he touched his tongue to a frosty latch all the skin would tear off it .<br>Jem had promptly done it , `` just to see if it was so . ''<br>He found it was `` so , '' at the cost of a very sore tongue for several days .<br>But Jem did not grudge suffering in the interests of science .
hypothesis: Susan and Jem are both adults.
reason: The text does not describe the ages of the two people involved in this "experiment", so they can be children or adults.