98 LABORATORY BACTERIOLOGY 
ae ics EXERCISE XL 
BACTERIOLOGIC EXAMINATION OF PUS AND 
EXUDATES 
150. It is often very desirable for diagnostic purposes to 
make a bacteriologic examination of the pus from abscesses 
and the mucopurulent discharges or exudates from mucous 
or serous membranes. 
Several diseases can be diagnosed in this way. It is often 
necessary to make cultures and it is always advisable to do so 
whenever the material is in a suitable condition. Among the 
specific diseases for which such an examination is especially 
valuable are actinomycosis, gonorrhea, diphtheria, and tuber- 
culosis. Further, it is often desirable to determine the genera 
of the bacteria in the numerous abscesses and suppurating 
wounds encountered in both man and the lower animals. ° 
Such examinations of the more desirable cases will be miade 
from time to time as they become available. In this exercise 
such cover-glass preparations will be examined as have been 
accumulated for this purpose. : 
151. Work for this exercise. Examine the pus in the fresh 
condition and note its composition, leucocytes, red blood 
corpuscles, fungi (actinomycosis), etc. 
Make cover-glass preparations and stain one or more of 
them with carbol fuchsin and one with alkaline methylene 
blue and examine. Note the cellular tissue elements present 
and describe the bacteria found. If the pus is from a case 
suspected to be of a specific nature, stain and examine for the 
corresponding organism. 
If actinomycosis, the ray fungus may be seen better in the 
fresh preparation. Add a drop of a 10% solution of caustic 
potash to a loopful of pus on the slide and cover it with a 
cover glass and examine. 
