io6 



BACTERIOLOGICAL METHODS 



Space will not permit discussing the methods thus outlined 

 nor is this essential for the present purpose. Those interested 

 are referred to the work by Prescott and Winslow, Elements of 

 Water Bacteriology (1913), which contains a fairly complete digest 

 of the methods. Furthermore, the methods adopted must be 

 suited to the special cases in hand. The most suitable procedure 

 for isolating the Bacillus typhosus from drinking water would 

 not be practicably applicable in the examination of typhoid con- 



FiG. 31. — B. typhosus from an agar culture 6 hr. old. Highly magnified 

 (X looo), showing the flagella; stained by the Loeffler method. — {McFarland after 



MacNeal.) 



taminated sewage or milk, for example. For the time being there 

 is no routine laboratory method for the isolation of the typhoid 

 bacillus and we must content ourselves with a brief consideration 

 of those methods which will in all probability give the best 

 results. 



It is of the highest importance that the food bacteriologist 

 should search out typhoid contaminated foods before the occur- 

 rence of an epidemic. In fact, if such work is not undertaken 

 until cases of typhoid have developed, the bacteriological find- 



