86 ISOLATION OF AEROBIC MICRO-ORGANISMS 



non-pathogenic species will be to inoculate the material into a suitable 

 animal. 



For example, to isolate the pneumococcus from pneumonic sputum a 

 little of the latter may be inoculated beneath the skin of a mouse ; the animal 

 will soon die and its blood will be found to contain a pure culture of the 

 pneumococcus. 



Similarly, to isolate the bacillus of malignant oedema from soil in which 

 there is also present a large number of other organisms, a little of the earth 

 is rubbed up into a thin emulsion in a few drops of sterile water and inocu- 

 lated beneath the skin of the abdomen of a guinea-pig. The animal dies 

 from an infection known as Pasteur's septicaemia, and the serous peritoneal 

 exudate will contain the bacillus in pure culture. 



Many opportunities of studying this method of isolating organisms will 

 occur later. 



