LIFE FROM A PHYSICAL STANDPOINT. 7 



tinue to go on or it will disintegrate at once. When the 

 proper temperature has once tumbled over the statically ar- 

 ranged molecules of the o.^^^ proper energy for continuing the 

 process must be furnished or the whole structure comes tum- 

 bling down and then we say the thing is dead. One may say 

 that heat or temperature did it, but it is better for clearness of 

 vision to see that these terms mean only a kind and rate of 

 motion and nothing else, and then one can understand better 

 how molecular stability depends upon temperature, whether in 

 an egg or in water. Hence in some way life is an affair of 

 atoms and molecules rather than of large and visible masses of 

 them. 



How large are the smallest masses that exhibit to the 

 biologist the phenomena of life } Each increase in magnifying 

 power has presented to him still smaller masses having this 

 quality. If one can now see living particles the hundred-thou- 

 sandth of an inch in diameter, is there any reason for suppos- 

 ing that such a particle is the smallest really living thing } 

 Certainly not. Well then, how much finer may matter itself 

 be divided } There is reason for believing that the atoms of 

 matter such as hydrogen, oxygen, and carbon are approximately 

 the fifty-millionth of an inch in diameter and a mass of matter 

 the hundred-thousandth of an inch in diameter would contain 

 125,000,000 such atoms. Would one think there would be any 

 probability in the proposition that the smallest living thing 

 must contain that number of atoms .'' If not, then what has the 

 microscope got to say as to what has been called spontaneous 

 generation } There might be millions of living things too 

 small to be seen, having any number of qualities, such as 

 growth, assimilation, reproduction, and so on, and this smallest 

 thing we see be only the last in a long succession of growths 

 and developments. Again if life be not a miraculous endow- 

 ment, would any one think there could be any probableness in 

 the proposition that the number of molecules and their ar- 

 rangement merely determines the presence or absence of life t 

 Does the number and arrangement of molecules determine 

 whether there shall be gravitation, or elasticity, or temperature 

 among them } 



