xi HAKDENING OF TISSUES 135 



(3) Keep the washed tissues in methylated spirit for a 

 week, and then place them in absolute alcohol. 



(4) Now embed in paraffin (56 to 60 0.) in the ordinary 

 and slower manner, cut and stain. 



Examine the sections, and compare them with the 

 others. 



Examination of Typhoid Spleen 



(1) Wash the surface of the spleen with sterilised water 

 and cauterise a small area with a red-hot glass rod. 



(2) Thrust a sterilised stout platinum loop through the 

 cauterised spot well into the spleen, and gently stir up the 

 pulp. 



(3) Withdraw the needle and inoculate three sloped 

 gelatine tubes, as described for the Bacillus diphtherise on 

 p. 106. 



(4) Place the tubes in a cool incubator and examine 

 them next morning. 



In most cases pure cultures are readily obtained from 

 a typhoid spleen. 



To confirm the diagnosis, sub-cultures must be made 

 in milk, broth, gelatine (stab and shake) ; broth 

 cultures (six to twelve days' old) must be tested 

 for Indol and young agar-agar cultures stained for 

 flagella (vide pp. 38 and 46). 



