136 ORIGIN AND NATURE OF LIFE 



just as if it had been compressed into a steel 

 gas cylinder, the pressure so developed 

 within the solution being called osmotic 

 pressure. This pressure means work done, 

 and the energy must be got from some other 

 form. It is obtained by the cooling of the 

 solution. If now, instead of the crystallized 

 substance, an equal amount of the dried salt 

 be used, then the temperature, in practically 

 every case, rises instead of falling, showing 

 that the energy set free by the molecular 

 affinity of the anhydrous salt and water, 

 is greater than the energy needed for the 

 development of the osmotic pressure energy. 

 In fact, the figures given above, in each case 

 only express the difference between these two 

 amounts of energy, and the true molecular 

 affinity is measured by an amount greater 

 than them, at present unknown to us. 



By what scheme can this molecular affinity 

 and valency be visualized ? The human 

 mind always searches for some outward 

 and visible sign of a scientific faith, so here 

 is a simile. 



Suppose the electrons and atoms and 

 molecules could be magnified by a powerful 

 microscope that would make the electrons 

 visible to the eye, then it may be supposed 

 that a system might be revealed such as the 



