30 MICRO-ORGANISMS AND DISEASE. [CHAP. 



pipette I draw the droplet to be used for inoculation, and 

 having made a very small incision about J of an inch 

 through the skin, the pointed end of the pipette is pushed 

 forward into the subcutaneous tissue for about half an inch 

 or one inch and then the fluid is blown out into the tissue : 



FIG. 6. HOT-WATER FILTER FOR FILTI-RING NUTRITIVE GELATINE OR 

 AGAR-AGAR MIXTURE. 



In this way I am always absolutely safe from any contami- 

 nation with a previously used virus, which might possibly 

 adhere to one or other part of a syringe. 



The fine point of capillary pipettes (Fig. 5), used for in- 

 oculation of animals, or for drawing out a drop of fluid of a 



