26 CLINICAL BACTERIOLOGY AND H^MATOLOGY 



hand or readily prepared by diluting" ordinary fuchsin with 

 water (about i to 10). Stain in this for a quarter of a minute 

 not more, for the stain is a very powerful one, and if allowed 

 to act too long may displace the stain from a Gram-staining 

 organism : wash for a minute or so under the tap, dry, and 

 mount. Organisms which retain Gram's stain will be violet, 

 almost black; organisms which do not will be red. Pus, blood, 

 etc., if present, will also be red. This counterstaining by 

 means of a good contrast stain is really almost a necessary 

 sequel to Gram's method, and in practical diagnostic work 

 the two almost always g'o together. 

 Dry and mount as before. 



