METHOD FOR STAININO FLAQELLA. 175 



the solution begins to steam. It should not be boiled. 

 After steaming, the mordant is washed ofiP in water and 

 finally in alcohol. The bacteria are then to be stained 

 in a saturated aniline-water-fuchsin solution. 



When treated in this way diiferent bacteria behave 

 differently : the flagella of some stain readily in the 

 above solutions ; others require the addition of an alkali 

 in varying quantities ; while others stain best after the 

 addition of acids. To meet these conditions an exact 

 1 per cent, solution of caustic soda in water must be 

 prepared, and also a solution of sulphuric acid in water 

 of such strength that one cubic centimetre will be ex- 

 actly neutralized by one cubic centimetre of the alkaline 

 solution. 



For different bacteria which have been studied by 

 this method Loffler recommends the one or the other of 

 these solutions to be added to the mordant in the follow- 

 ing proportions. 



Of the acid solution : 



For spirillum choleree Asiaticse, i to 1 drop of acid to 16 c.c. of mordant. 

 For spirillum rutrum, 9 " " " " 



For spirillvm MetucTmikoffi, 4 " " " " 



For hacillus pyocyanens, 5 " " " " 



For spiriUum concentricum, no addition of eitiier acid or alkali. 



Of the alkaline solution : 



For bacillus mesentericus vulgatus, 4 drops of alkali to 16 c.c. of mordant 



For micrococcus agilis, 20 " " " 



For bacillus typhosus, 22 " " " 



For bacillus mbtilis, 28-30 " " " " 



For bacillus wdematis maligni, 36-37 " " " " 



For bacillus anthracis symp- 1 

 tomatici, > 



The drops used run 22 to the cubic centimetre. 

 For other organisms one must determine whether the 

 results are better after the addition of acid or alkali, 



