Those with a little awareness of chemistry and physics will be conscious of molarity and the gas laws. These tell us that, for example, eighteen grammes of water would be equivalent to twenty-two and a bit litres of steam at the same temperature. So far, so boring. However, consider drinking a room temperature liquid which boils below body temperature, for instance diethyl ether. Forty-six grammes of this room temperature liquid becomes twenty-two litres of body temperature gas, the density of the liquid being 3/4 that of water.
