8o 



EXERCISE Iv. 



BACTERIOLOGICAL EXAMINATION OF PUS AND EXUDATES. 



§ 140. Explanatory note. It is often very desirable for 

 diagnostic purposes to make a bacteriological examination 

 of the pus from abce,sses and the muco-purulent 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 tuberculosis. It is often desirable to determine the 

 character of the bacteria in the numerous abce.sses and sup- 

 purating wounds encountered in both man and the lower 

 animals. These examinations will be made from the more 

 desirable cases as they appear from time to time. In this 

 exercise such cover-glass preparations will be examined as 

 have been accumulated for this purpose. 



§ 141. General directions. Examine the pus in the fresh 

 condition and note its composition, leucocytes, red blood 

 corpusles, 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 celluar tissue elements present 

 and also describe the bacteria found. If the pus is from a 

 case su.spected 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 \o% solution of caustic 

 potash to a loopful of pus on the slide and cover with a 

 cover-glass and examine. 



If gonorrheal discharge, stain the cover-glass preparations 

 with alkaline methylene-blue or with carbol fuch,sin. Note 



