156 BACTERIOLOGY. 
Or it may be prepared by adding to a 5 per cent. watery solution of 
carbolic acid enough of the saturated alcoholic solution of fuchsin al- 
most to saturate it. Taking some of this solution in a watch glass, pro- 
ceed as by the previous method. Decolorize with strong alcohol alone, 
rinse in water, and double stain with the methylin-blue solution. 
In staining the flagelle found on motile bacteria, what precautions 
should be taken and what solutions should be used ? 
The cover glasses should be absolutely free from all greasy material, 
and are best cleaned by warming them in strong sulphuric acid for a 
time. After this they should be rinsed in water and kept in a mixture 
of equal parts of alcohol and ammonia, When wanted for use they 
should be wiped with a cloth that has been freed from all greasy 
material. As a mordaunt the following solution is used: 
R Tannic-acid solution (acid, 20 parts; water, 80 
Parts) ccccossssesetasys beerncdewesceuneedeaeweuress 10 ee. 
Cold saturated solution ferri. sulph..............-+- 5 ce. 
Saturated watery or alcoholic solution of fuchsin. 1 ce. 
As staining agent use a saturated aniline water solution of fuchsin. 
Other solutions necessary are a 1 per cent. watery solution of caustic 
soda and a watery solution of sulphuric acid of such strength that 1 ce. 
of the acid solution is exactly neutralized by 1 cc. of the soda solution. 
Give the process for staining flagelle. 
Several cover glasses are prepared with a drop of clean water upon 
each. With a platinum wire adrop from the specimen to be examined 
is thoroughly mixed with the water on the first cover glass. Thena 
drop of this mixture is mixed with the water on the second cover glass, 
and so on until five or six dilutions have been made, in order that the 
individual bacteria may be sufficiently separated. The cover glass to 
be stained is dried and the specimen fixed upon it in the usual way. 
Upon this a few drops of the mordaunt solution is put and treated 
until it steams. It should never be boiled. Next, after rinsing with 
water, the specimen is stained with the aniline water fuchsin and again 
rinsed in water, dried and mounted in Canada balsam. The flagellze 
of some bacteria require the addition of a few drops of the soda solu- 
tion, and those of others of one-half a drop or more of the acid solution, 
in order that they may take the stain. 
Give the steps necessary for staining tubercle bacilli. 
1. Smear on + cover glasses. 
+ For purposes of diagnosis always use NEW slides and cover glasses. 
