56 CLINICAL BACTERIOLOGY AND HEMATOLOGY 



methods will be described, since more information is required, and 

 this information the general practitioner is usually in the best 

 situation to obtain. 



Methods. — If possible, the sputum should be obtained in a 

 method similar to that recommended in pneumonia, as it greatly 

 facilitates the process and renders the results more trustworthy if 

 the sputum comes directly from the lungs, and is not contaminated 

 with bacteria from the mouth. The nasal secretion may also be 

 examined, and frequently contains the organisms in pure culture 

 and vast numbers ; where the nose is affected, better results will 

 be obtained in this way than from the sputum. The mucus may 

 be collected on a diphtheria swab or on a platinum loop, or by 

 means of one of the angled pipettes described on p. 129, though 

 it is often too thick to be sucked up into such a narrow tube. 



Films are prepared from the sputum by squeezing a small mass 

 between two slides and sliding them apart. Dry and fix by heat. 

 Two should be prepared. The first should be stained by Gram's 

 method, and counterstained by dilute carbol fuchsin for a quarter 

 of a minute, then washed, dried, and mounted. The other is to be 

 stained more deeply with carbol fuchsin or Loffler's blue — about 

 five minutes with gentle heat in either case. The influenza bacillus 

 stains with difficulty, and may not be seen in the Gram's specimen 

 which is lightly stained with fuchsin. And there is a good reason 

 for not carrying the counterstaining too far in the former case, 

 since if the carbol fuchsin is used for too long a time it may dis- 

 place the violet stain of an organism which retains Gram. 



The influenza bacillus is an extremely minute organism, and one 

 which requires the highest powers of the microscope for its study. 

 It is an extremely minute rod, and it would take from eight to^ 

 sixteen of these rods to make up the diameter of a red blood- 

 corpuscle. They occur in vast numbers in the sputum or nasal 

 mucus, and are frequently found within the leucocytes, and when 

 in this situation may appear to have a capsule, being contained in 

 vacuoles in the protoplasm (Plate II., Fig. 3). They are often 

 arranged in pairs, in which case they might be mistaken for small 

 but unusually elongated pneumococci, but for the fact that they 

 do not stain by Gram's method. 



These features are sufficient to identify them for clinical 

 purposes. Cultures are difficult to obtain, since the organism 

 only grows in presence of haemoglobin — e.g., on agar tubes streaked 

 with sterile blood (see p. 87). Under these circumstances they 



