BACTEmOLOGY. 



INTRODUCTION. 



" Omne vivum ex vivo " — The overthrow of the doctrine of spontaneous 

 generation — Earlier bacteriological studies — The birth of modern 

 bacteriology. 



Bacteriology may be said to have had its begin- 

 ning with the observations of Leeuweuhoek in the latter 

 part of the seventeenth century. Though its most rapid 

 and important development has taken place during the 

 past fifteen or twenty years, still, a review of the vari- 

 ous evolutionary phases through which it has passed 

 in the course of more than two hundred years re- 

 veals an entertaining and instructive history. From 

 the very outset its history is inseparably connected 

 with that of medicine, and from the outcome of bacte- 

 riological research preventive medicine, in its modern 

 conception, received its primary impulse. Through a 

 more intimate acquaintance with the biological activi- 

 ties of the unicellular vegetable micro-organisms modern 

 hygiene has attained almost the dignity of an exact 

 science, and properly merits the importance and promi- 

 nence now generally accorded to it. From studies in 

 the domain of bacteriology our knowledge of the causa- 

 tion, course, and preveution of infectious diseases is 

 daily becoming more accurate, and it is needless to em- 

 phasize the relation of such knowledge to the manifold 

 problems that present themselves to the student of 

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