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posing a profitless labor of demolition on subsequent in- 

 vestigators. The proper and possible attitude of these 

 two men is that each of them should work as if it were 

 his aim and object to establish the view entertained by 

 the other. 



I trust, Mr. President, that you whom untoward cir- 

 cumstances have made a biologist, but who still keep 

 alive your sympathy with that class of inquiries which 

 nature intended you to pursue and adorn will excuse 

 me to your brethren if I say that some of them seem to 

 form an inadequate estimate of the distance which sep- 

 arates the microscopic from the molecular limit, and 

 that, as a consequence, they sometimes employ a phrase- 

 ology which is calculated to mislead. 



When, for example, the contents of a cell are de- 

 scribed as perfectly homogeneous, as absolutely struc- 

 tureless, because the microscope fails to distinguish any 

 structure, then I think the microscope begins to play a 

 mischievous part. A little consideration will make it 

 plain to all of you that the microscope can have no voice 

 in the real question of germ structure. Distilled 

 water is more perfectly homogeneous than the contents 

 of any possible organic germ. What causes the liquid 

 to cease contracting at 39 F., and to grow bigger until 

 it freezes ? It is a structural process of which the 

 microscope can take no note, nor is it likely to do so 

 by any conceivable extension of its powers. Place this 

 distilled water in the field of an electro-magnet, and 

 bring a microscope to bear upon it. Will any change 

 be observed when the magnet is excited ? Absolutely 

 none ; and still profound and complex changes have 

 occurred. 



First of all, the particles of water are rendered dia- 



