26 LABORATORY BACTERIOLOGY 
forms, the spores in spore-bearing organisms, and the capsule 
on certain other species. There is a large number of these 
special methods, but in this course only one of each will be 
given. These will be taken up in connection with the study 
of the bacteria requiring them. 
37. Formule for staining solutions. The dyes here used 
are methylene blue, gentian violet, methyl violet, and basic 
fuchsin. For the other dyes, see text-books. 
ALKALINE METHYLENE BLUE (LOEFFLER) 
Saturated alcoholic solution of methylene blue. 6 cc. 
Caustic potash (1% solution). . s&s oreavhh 
Distilled water 2. . 1. 1 ew ee ee) 20 
The saturated alcoholic solution of the methylene blue (or 
of any of the dyes) is prepared by pouring the dye into a clean 
bottle and filling it about one fourth full. Then fill the bottle 
with strong (95% or absolute) alcohol, cork tightly, shake, and 
allow it to stand for 24 hours. If at the end of that time the 
dye is entirely dissolved, add more, shake thoroughly, and allow 
it to stand for another day. Repeat this procedure until there 
is a permanent sediment of undissolved coloring matter in the 
bottom of the bottle. Then label. (The saturated solution 
will be kept in stock in the laboratory.) 
CARBOL FUCHSIN (ZIEHL’S SOLUTION) 
Fuchsin (dry). . . . . , . + os .  Tgram 
Alcohol (absolute) . . ©. «© «©. . . 1 « Toce. 
Carbolic acid (5% solution) . . . . . . . Iooce. 
Dissolve the fuchsin in the alcohol, after which add the car- 
bolic acid solution. Instead of using the dry fuchsin and 
alcohol, 11 cc. of a saturated alcoholic solution of fuchsin may 
be used. 
It is more convenient for each student to prepare the 
following : — k 
Saturated alcoholic solution of fuchsin. . . . 3cc. 
Carbolic acid (5% solution) . .... .. 30 o 
