476 BACTERIOLOGIC TECHNIC. 



Czaplewski and E. Frankel recommend that instead of anilin water, 

 2.5% carbolic acid water be employed. This has the advantage that 

 the solution does not decompose so soon as anilin mixtures. 



5. Loffler's Methylene-blue. — To 100 c.c. of water is added 1 c.e. 

 of 1% solution of potassium hydroxid, and 30 c.c. of concentrated 

 alcoholic solution of methylene-blue. The staining property of the 

 dye is intensified by the addition of the alkali. 



6. Acetic acid methylene-blue, according to M. Neisser, tor the 

 staining of granules : 



(a) 1.0 gm. of methylene-blue is dissolved in 20 c.c. of 90% alcohol, 

 and to this is added 950 c.c. of distilled water and 50 c.c. of glacial 

 acetic acid. 



( 6 ) 2. gm. of Bismarck brown are dissolved in 1 liter of boiling dis- 

 tilled water (filter !). 



7. Bismarck Brown. — Prepared like No. 1 (stains tissues, but stains 

 bacteria poorly). 



8. Alum Carmin. — In 100 c.c. of a 5% solution of alum 2 gm. of 

 carmine are placed. It is boiled for an hour and filtered. It stains 

 nuclei and tissues, but not bacteria. 



9. Eosin. — For staining the tissues about the bacteria. Two gm. 

 of eosin are dissolved in 100 c.c. of distilled water. 



10. Safranin. — Three gm. of safranin are dissolved in 100 c.c. of 

 hot distilled water. 



(B) Differentiating Agents. 



1. Distilled water. 



2. Absolute alcohol. 



3. lodin, iodid of potassium solution (Gram's solution): 



lodin. pur ... 1.0 gm. 



Potassii iodid. ... ... . 2.0 " 



Distilled water 300.0 " 



4. Sulphuric acid, 25%. 



5. Acetic acid, 3%. 



6. Acid alcohol : 



Alcohol (90%) 100 c.c. 



Distilled water 200 " 



Pure hydrochloric acid 20 drops. 



(C) Mordants for Staining Flagella. 



1. Loffler's mordant : 10 c.c alcoholic solution of fuchsin ; 50 c.c. 

 cold saturated solution of ferrosulphate ; 100 c.c. 20% solution of 

 tannic acid. 



2. Bunge's mordant : 25 c.c. of officinal solution of ferric chlorid, 

 diluted twenty times ; 75 c.c. of a saturated aqueous solution of tannic 

 acid. Just before using, enough of a 3 % solution of hydrogen peroxid 

 is added to give a reddish-brown color, and it is then filtered. (We 

 have always dispensed with this last addition. ) 



