BACTERIOLOGY. 



INTRODUCTION. 



Omiie vivuni ex vivo" The overthrow of the doctrine of 

 -|H>nt;uifoiis generation. 



THE study of Bacteriology may be said to have had 

 its birth with the observations made by Antony van 

 Leeuwenhoek in the year 1675. Though it is during; 

 the past decade and a half that this line of research has 

 received its greatest impulse, yet by a review of the 

 developmental stages through which it has passed in its 

 life of more than two centuries, we see that it has a 

 most interesting and instructive history. From the very 

 beginning its history is inseparably connected with the 

 history of medicine, and as it now stands its relations to 

 hygiene and preventive medicine are of the most im- 

 portant nature. It is, indeed, to a more intimate ac- 

 quaintance with the biological activities of the micro- 

 organisms that modern hygiene owes much of its value, 

 and our knowledge upon infectious diseases has been 

 developed to the position it now occupies. Though the 

 contributions which have done most to place bacteriology 

 on the footing of a science are those of recent years, still, 

 during the earlier stages of its development, many obser- 

 vations were made which formed the foundation work 

 for much that was to follow. Before regularly begin- 

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