TECHNICAL APPENDIX. 169 



4. Aniline gentian (Ehrlich's solution) : To 100 

 c.c. aniline water add 11 c.c. of an alcoholic con- 

 centrated gentian violet solution (stock solution). 

 This solution does not keep long. 



5. Loffler's methyl blue: To 100 c.c. water, which 

 contains 1 c.c. of a one-per-cent potash lye, add 

 30 c.c. of a concentrated alcoholic solution of methyl 

 blue. The staining power is increased by the addi- 

 tion of the alkali. 



6. Bismarck brown: Prepare like No. 1. (Stains 

 tissues, but bacteria poorly). 



7. Alum carmine: To 100 c.c. of a five-per-cent 

 alum solution add 2 gm. carmine, boil for an hour, 

 and filter. 



B. Differentiation Measures. 



1. Distilled water. 



2. Absolute alcohol. 



3. Iodine-potassium iodide solution (Gram). 



lodin. pur 1.0 



Potassii iodidi 2.0 



Aq. destil 300.0 



4. Sulphuric acid (twenty -five per cent). 



5. Acetic acid (three per cent). 



6. Acid alcohol. 



Alcohol (ninety per cent) 100 c.c. 



Distilled water. 200 u 



Pure hydrochloric acid 20 gtt 



C. Mordants for the Flagella. 

 Loffler's mordant: 

 10 c.c. alcoholic solution of fuchsin. 

 50 c.c. cold saturated ferrosulphate solution. 

 100 c.c. twenty -per-cent tannin solution. 



