CHAPTER XI 

 PNEUMONIA 



T OBAR or " croupous " pneumonia is due to a 

 *"^ micrococcus discovered by the present writer in 

 1880 and since demonstrated to be the cause of this 

 infectious disease. The micrococcus of pneumonia is 

 found in great numbers in the exudate which fills the 

 air cells of the portion of the lung involved (one or 

 more lobes) and in the sticky sputum coughed up 

 by the patient. This is " rusty " in appearance on ac- 

 count of the presence of red blood-corpuscles. In 

 fatal cases of pneumonia the micrococcus is not infre- 

 quently found, also, in the blood of the infected indi- 

 vidual, but as a rule the disease may be regarded as a 

 localised infection. The symptoms are due in part to a 

 deficient supply of oxygen from the occlusion of the 

 air cells in one or more lobes and in part to the 

 absorption of the toxin produced by the micrococcus. 

 The fatality of the disease depends largely upon the 



extent of lung tissue involved and also upon the age 



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