CHAPTER IV 



EXAMINATION OF BACTERIA, MICROSCOPIC DIAG- 

 NOSIS, ETC 



INASMUCH as only those nurses who become surgical 

 assistants or laboratory workers will be concerned in the 

 details and specific methods of bacterial examination 

 and technic, no attempt will be made here to present 

 such methods in detail. Those who are interested in 

 such laboratory technic are referred to the more pre- 

 tentious works for physicians and medical students. 



Owing to their minute size, bacteria can only be ex- 

 amined by means of a high-power microscope, assisted 

 by a device known as an oil-immersion lens, in which a 

 drop of cedar oil is interposed between the lens and the 

 cover-glass, beneath which is the object to be observed, 

 the purpose of such device being to concentrate all of 

 the rays of light emerging from the specimen observed. 

 In addition there is needed an Abbe condenser, a device 

 for concentrating the rays upon the object viewed. 



Being provided with the proper apparatus, the speci- 

 men may be examined in several ways. If the specimen 

 be from a liquid culture, a drop may be taken on a 

 platinum loop placed between a cover-glass and slide 



