REMAKES ON TECHNIQUE 



After fixation of the smear 



1. Stain for twenty-five seconds in the following solution : 



5 per cent, watery sol. of gentian violet 1 ... ... 88 parts 



Ol. anilin pur. ... ... ... ... ... 2 



Abs. alcohol ... ... ... ... ... 10 



Filter before using. 



2. Wash with water. 



3. Iodine in pot. iodide solution (1:2: 300) fifteen seconds ; the preparation 



must take on a dark brown tint. Then, without washing, 



4. decolorize with absolute alcohol till no colour washes out. 



5. Wash in water. 



6. Counter-stain with 5 per cent, watery safranin or weak fuchsin for five 



seconds. 



7. Thoroughly wash with water, dry, and examine in water, oil, or Canada- 



balsam. 2 



When this method is carried 

 out exactly, films are obtained 

 quite free from granular debris 

 of the stain, and the modifica- 

 tions suggested by Unna and 

 others to prevent such con- 

 tamination, and to procure a 

 clean decolorization, are quite 

 unnecessary, and can be neg- 

 lected. 3 Clear colour contrasts 

 can always be obtained. The 

 Gram - positive bacteria stain 

 dark blue ; the Gram-negative 

 bacteria, the cells, exudate, and F rG . i._ SECRETION CONTAINING INFLUENZA 

 other tissues, take up the con- BACILLI (BED) AND XEROSIS BACILLUS 



' (BLUE). GRAM STAIN, (x 1,000.) 



trast stain and are red. 



1 Loffler (Deidsche Med. Woch., 1906, p. 1244) states that methyl violet 6B or BN, 

 dissolved in 1 to 2 per cent, carbolic in a proportion of 1 : 10, gives better results. 

 ' 2 Another commouly-tised modification is the Gram stain according to Czaplewski : 



1. One minute in carbol gentian (sat. alcoholic sol. of gentian violet, 50 c.cm ; 

 5 per cent, carbolic ac." watery sol., 50 c.cm. ; aq. dist., 50 c.cm.). 



2. Wash. 



3. Thirty to sixty seconds in Lngol's solution (iod., 1 ; pot. iod., 2 ; aq., 300). 



4. Wash ; dry with filter-paper. 



5. Differentiate in anilin xylol (2 : 1 + 1 '5 per cent, acetone). 



6. Wash in xylol ; dry in air. 



7. Counter-stain for one minute in carbol-glycerin-fuchsin (1 fuchsin triturated with 

 5 of ac. carbol. liq., 50 glycerin, and 100 c.cm. aq. dist.). 



8. Wash and dry. 



Should differentiation be difficult, carefully add 1 drop of alcohol to the anilin xylol. 

 ' Fibrin and richly nucleated structures are more easily differentiated if the material be 

 spread on the slide with water.' 



3 The original Gram prescription for the watery anilin-gentian-violet (add drops ot 

 sat. solution of gentian violet in alcohol to auilin water until a coloured scum occurs) does 

 not stain deeply enough, and gives a slight deposit. Gram's original prescription can no 

 longer be recommended. 



