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 .
Jem's tongue was not affected by sticking it to the latch