METHOD OF STRAUSS AND WtJRZ 



101 



gelatine (liquefaction). The germs may then be isolated 

 by further transference to culture plates, and submitted to. 

 microscopic examination. 



Glass tube Rubber cork 



Aspirator 



Fig. 31. — Hesse's ArpAitATus iuk i;x^\.min'jxg Air. 



Method of Strauss and Wiirz. — Air is drawn into a glass 

 vessel full of liquid gelatine by means of a tube affixed to 



Aperture for the admissiou of air 



Vessel filleil with gelatine 



Lateral tubuluie 



Pig. 32.— Aiii-TEsTiKG Apparatus of Stbai >s and Wukz. 



the side and connected with an aspirator (fig. 32). A large 

 volume of air, 100 to 200 litres, is thus tested, and when 

 the aspiration is concluded the gelatine is poured out on 



