38 BACTERIOLOGICAL DIAGNOSIS. 



3. Carbol-fuchsin is made by adding a saturated al- 

 coholic solution of fuchsin to carbolic acid lotion (i in 

 20) until the fluid has lost its transparency. This 

 keeps well. 



4. The above stain diluted with four or five times its 

 volume of water. Label "dilute carbol fuchsin" 



5. Aniline gentian violet, which is prepared as follows: 

 First prepare aniline oil water by shaking water 



(preferably distilled) with more aniline oil than it will 

 dissolve ; a milky emulsion will result, and this must 

 be allowed to settle for a short time. [Then filter it 

 through a double thickness of filter paper which has 

 been previously moistened with water. 



To 9 parts of the solution thus obtained add i part of 

 saturated solution of gentian violet. 



This solution keeps badly, and it is of great import- 

 ance that it should be freshly prepared, as very 

 important inferences are drawn from results obtained 

 with it. The following keeps better, and answers every 

 purpose. 



Carbolic gentian violet. (A substitute for aniline gen- 

 tian violet). 



Add i part of saturated alcoholic solution of gentian 

 violet to 9 parts of a i in 20 carbolic lotion. 



6. Carbol -thionin is made by adding i gramme of 

 thionin to 100 c.c. of a i in 40 solution of carbolic 

 acid. 



This stain keeps fairly well, but it must always be 

 filtered immediately before use, as crystals which may 

 have a most delusive resemblance to long slender bacilli 

 are frequently deposited in it. A similar formation of 

 crystals also occurs if the stain be allowed to dry on the 

 slide. 



7. Eosin is used in a 4 or 5 per cent, watery solution. 



