390 JAMES CLERK MAXWELL. [CHAP. XII. 



To PROFESSOR LEWIS CAMPBELL. 



Gknlair, Dalbeattie, 26th September 1874. 



JBt. 43. Yours of the 29th instant is to hand. Whether your 



devotion to Michael Angelo has urged you to anticipate his 

 day, or whether Time gallops with those who sit to view 

 Necessity, with her weary pund o' tow massed round her 

 rock, being all the remains of the stane o' lint with which 

 she was originally endowed, those who may be set to con- 

 strue this sentence will be apt to lose much time. 



With regard to atoms, I am preparing a hash of them 

 for Baynes of the Britannica. The easiest way of showing 

 what atoms can't do is to get some sort of notion of what 

 they can do. If atoms are finite in number, each of them 

 being of a certain weight, then it becomes impossible that the 

 germ from which a man is developed should contain (actually, 

 of course, not potentially, for potentiality is nonsense in 

 materialism unless it is expressed as configuration and 

 motion) gemmules of everything which the man is to inherit, 

 and by which he is differentiated from other animals and men, 

 his father's temper, his mother's memory, his grandfather's 

 way of blowing his nose, his arboreal ancestor's arrangement of 

 hair on his arms, and his more remote littoral ancestor's 

 devotion to the tide-swaying moon. Francis Galton, whose 

 mission it seems to be to ride other men's hobbies to death, 

 has invented the felicitous expression " structureless germs." 

 Now, if a germ, or anything else, contains in itself a power 

 of development into some distinct thing, and if this power is 

 purely physical, arising from the configuration and motion of 

 parts of the germ, it is nonsense to call it structureless 

 because the microscope does not show the structure ; the 

 germ of a rat must contain more separable parts and organs 

 than there are drops in the sea. But if we are sure that 

 there are not more than a few million molecules in it, each 

 molecule being composed of component molecules, identical 

 with those of carbon, oxygen, nitrogen, hydrogen, etc., there 

 is no room left for the sort of structure which is required 

 for pangenesis on purely physical principles. Again, suppose 

 that a great many individual atoms take part in a disturb- 



