22 MODERN BIOLOGIC THERAPEUSIS 



tically isolated and without fruit for nearly a 

 century. It was not until 1786 that the w r ork of 

 the Danish zoologist, Mueller, added anything 

 of importance to the knowledge of bacteria. 



Edward Jenner (1749-1823). 



Mueller succeeded in discovering many struc- 

 tural details of which his predecessors had been 

 ignorant. He succeeded in depicting several 

 kinds of bacteria so accurately that they can be 



