64 BACTERIOLOGICAL DIAGNOSIS. 



INFLUENZA. 



The diagnosis of influenza is often very difficult, and 

 a simple bacteriological examination should be made 

 in all cases. The cultivation of the specific bacillus 

 is by no means easy, but this does not matter, as an 

 examination of stained films will usually permit of a 

 diagnosis. 



The influenza bacillus occurs in the sputum and 

 occasionally in the blood. It may be searched for in 

 the latter situation, but the quest is a very difficult one. 

 In the sputum it occurs in vast quantities and is almost 

 free from other germs. 



The method by which the sputum is collected is the 

 same as that employed in pneumonia ; a mass of 

 greenish-yellow muco-pus is selected for examination, 

 squeezed between two slides, and the films dried and 

 fixed as in the case for the examination for the tubercle 

 bacillus. One is stained for five minutes with dilute 

 carbol-fuchsin or Loffler's blue, the slide being slightly 

 warmed, and the other by Gram's method. 



EXAMINATION OF THE SPECIMENS. 



The specimen stained with carbol-fuchsin or Loffler's 

 blue should be taken first and examined under the oil 

 immersion lens. The bacilli (in a positive case) will 

 be seen in vast numbers as extremely minute rods ; it 

 would take from twelve to sixteen of these rods to make 

 up the diameter of a red blood corpuscle. They fre- 

 quently occur within the pus cells, and when in this 



