Ah, The Metaphorical Powers of Mr. Asimov

British chemist Joseph Black (1728-1799) was able to show that the mere quantity of heat was not all there was to "hotness," or to temperature, as it is properly called. Suppose you take a piece of iron and a piece of lead, both weighing the same and equally hot. You place each into a separate container of cold water. In each case, the metal loses heat, which flows into the water, so that the metal cools down and the water warms up till, in each case, the transfer of heat is complete. You would expect that the water would be warmed equally in both cases, but that is not so. The water in which the hot iron is immersed is distinctly warmer than the water with the hot lead in it. Both metals were equally hot, and therefore had an equal temperature, but the iron contained more heat.

- Asimov