38 BACTERIOLOGICAL DIAGNOSIS. 
3. Carbol-fuchsin is made by adding a saturated al- 
coholic solution of fuchsin to carbolic acid lotion (1 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 cavbol-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 g parts of the solution thus obtained add 1 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 1 part of saturated aicpiiane solution of gentian 
violet to g parts of a 1 in 20 carbolic lotion. 
6. Cavtol-thionin is made by adding 1 gramme of 
‘thionin to 100 c.c. of a 1 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. 
