130 BACTERIOLOGICAL DIAGNOSIS. 



the staining method has been appropriate, by the pre- 

 sence in its protoplasm of minute granules which stain 

 with eosin. The fluid may also contain red blood 

 corpuscles and shreds of fibrin. 



This examination is hardly necessary except in cases 

 in which a tubercular origin is suspected. 



c. Chemical. Cerebro-spinal fluid removed from a 

 person who is not suffering from meningitis contains a 

 very minute amount of albumen, while when the 

 meninges are inflamed the quantity is greatly increased. 

 The method of testing these small amounts of albumen 

 are hardly within the reach of practitioners ; if a con- 

 siderable amount of fluid has been obtained a small 

 quantity should be tested by heat and acetic acid and 

 the amount of opacity noted. 



d. Bacteriological. The chief organisms which cause 

 acute meningitis are given in the following table, which 

 is modified from one given by Osier : 



Primary (i.e. not dependent on an obvious lesion elsewhere in the 

 body). 



1. Cerebro-spinal fever 



a. Sporadic | Weichselbaum's diplococcus. 



b. Epidemic \ 



2. Pneumococcic 



a. Pneumococcic infection of meninges alone 



not dependent on disease of distant parts of 



the body. Pneumococ- 



b. Pneumococcic infection of meninges occurring C ns. 



as part of a general septicaemia without 

 obvious primary lesion. 



Secondary. 



A. To direct extension from local disease of the cranium, middle 

 ear, fossae, spinal column, &c. 

 Pneumococcus. 

 Staphylococci. 

 Streptococci, &c. 



