BACTERIOLOGICAL EXAMINATION OF MATERIAL 221 



animals, the tracheal mucus, as well as the mucous membrane of the 

 posterior portions of the healthy nose, are usually sterile, although 

 the vestibulium nasae is usually heavily contaminated. When the 

 nasal cavity and the septum were artificially inoculated with Bacil- 

 lus prodigiosus, the organisms disappeared in about two hours. 

 These observers believed that the healthy nasal mucus is not bac- 

 tericidal, but does not favor growth. They examined air which 

 passed through the nose, and found that in the case of air which con- 

 tained over 20 mould spores and 9 bacteria per cubic centimeter, these 

 organisms almost entirely disappeared in the passage of the air through 

 the nose. Hilderbrandt 8 has previously obtained similar results in 

 Baumgarten's laboratory. Wright 9 also has made similar investiga- 

 tions, and showed that between 3 / 4 to 4 / 5 of the bacterial flora of 

 the inspired air was held back in its passage through the nose. 



Among the most interesting studies along these lines are those 

 of Neumann 10 who studied the nasal secretions of over 200 people, 

 of which about 111 were supposedly normal. Neumann found in 

 normal noses a very large number of different microorganisms. The 

 percentage findings of various bacteria were as follows: 



Pseudo-diphtheria (probably including diphtheroids) 98 to 100 per cent 



Micrococcus albus 98 per cent 



Micrococcus aureus 30 per cent 



Streptococcus lancelatous (probably pneumococcus) 4 per cent 



Friedlander bacilli 6 per cent 



Micrococcus citreus 12 per cent 



Colon bacilli 12 per cent 



Streptococcus 2 per cent 



Molds 20 per cent 



Sarcinae 6 per cent 



Lactis aerogenes 4 per cent 



Yeasts 2 per cent 



Neumann mentions other microorganisms in addition to these, 

 but the figures given are sufficient to show that the normal nose 

 may contain almost any of the known organisms including a great 

 many of the non-pathogenic forms in air, of which the bacteriologist 

 dealing with disease knows very little as a rule. Calamida and 



* Hilderbrandt, Baumgarten's Jahresb., 4, 1888, 378. 

 9 Wright, quoted from Baumgarten 's Jahresb., 5, 1889. 

 "Neumann, Zeit. f. Hyg,, 40, 1902, 33. 



