66 GENERAL BACTERIOLOGY LESSON xiv 



Stain another section according to Weigert's fibrin 

 method : 



(a) Place it in aniline gentian- violet for half an hour to 

 one hour. 



(b) Wash it in -6 per cent saline solution. 



(c) Now place it in the iodine solution (iod. 1, pot. 

 iod. 2, and water 100) for two to three minutes. 



(d) Wash it again in *6 per cent saline solution. 



(e) Decolourise it with the aniline oil and xylol mixture 

 (vide p. 52). 



(/) Wash thoroughly with xylol to remove all the 

 aniline oil. 



(g) Mount and examine it. 



In most cases the fibrin network of the diphtheritic 

 membrane will be beautifully stained, and the 

 bacilli always stand out well. 



It is desirable when dealing with paraffin sections, 

 fixed on cover -glasses, to perform the various washings, 

 decolourisations, counterstainings, and clearings in wide- 

 necked bottles, holding the cover-glasses in a pair of 

 forceps. 



