ISOLATION OF THE PNEUMOCOCCUS 591 



be found in the blood during the last days or last hours of life. The presence of 

 the organism in the peripheral circulation does not however necessarily imply a 

 fatal issue. 



The blood should be examined microscopically, culturally and by inoculation 

 into mice. The blood can be collected either by pricking the finger or from 

 a vein at the bend of the elbow (p. 193). Widal recommends sowing 5 c.c. 

 of blood in 300-500 c.c. of broth : by this method he has been able to isolate 

 the pneumococcus from the blood of persons suffering from pneumonia in 

 one-third of the cases examined. 



B. After death. (The post mortem examination should be made as soon 

 as possible after death.) The examination of the following fluids and tissues 

 will suffice for the detection of the pneumococcus. 



(a] The inflammatory exudate in the lung. Cauterize the surface of an 

 hepatized area. Introduce a Pasteur pipette and aspirate the fluid. With 

 the material prepare cover-glass preparations, sow culture media and inoculate 

 a mouse. 



(6) Sections of the lung. Put a few small pieces of the hepatized area of 

 the lung at once into alcohol or acid perchloride. They must be subsequently 

 embedded in paraffin, cut and stained by the methods described on pp. 216 

 and 219. 



(c) Pus and exudates.- Collect the material in the ordinary way and then 

 prepare films, sow cultures and inoculate a mouse. 



II. In animals. In animals the following tissues and fluids may be examined 

 for the pneumococcus viz. the blood, bone marrow, pleural fluid, peritoneal 

 exudate, pericardial effusion, films and sections of the internal organs, etc. 



Blood films and scrapings from tissues should be examined microscopically. 

 Cultures on rabbit serum sown with the blood, bone marrow, and exudate 

 will yield pure cultures which can be used for inoculation of other animals. 



Portions of the internal organs for sections should be fixed in alcohol or 

 acid perchloride and embedded in paraffin. 



