194 BIOGRAPHIES OF SCIENTIFIC MEN 



elements of this world to be distributed as they are and 

 in such proportions ? Why gold rarer than iron, and 

 iron than clay? Why the optical rotation of life-com- 

 pounds (such as tartaric acid, lactic acid, etc.), and not 

 of the synthetical acids? Why a globe adapted not 

 merely in the quality of its materials but in their quantity 

 and distribution to the wants of living beings and to 

 their evolution ? Kelvin answered firmly and unwaver- 

 ingly : "Because all living things depend on one ever- 

 acting Creator and Ruler.' 1 



Lord Kelvin had a limp, which was due to his early 

 enthusiasm for curling. He had the misfortune to break 

 his leg twice on the ice, and a third time it had to be 

 rebroken in order to make a better setting. 



The Manchester philosopher Joule had investigated the 

 phenomena attending the evolution of heat during the 

 passage of a current through an electrolyte, and it was 

 proved that the total quantity of heat could be separated 

 into two parts. " One part was expressible as the result 

 of overcoming ordinary resistance, and the other part 

 was due to chemical changes in the cell. He then de- 

 termined the quantity of heat evolved, during a given 

 time, in a process of electrolysis by a current of given 

 strength ; then, by applying Ohm's law, and the law 

 stated connecting heat with resistance and current, he 

 found the heat which would have been evolved, had a 



