94 THE AMERICAN MONTHLY [March 



method of staining, and to stick to the one method, as 

 by constant practice he becomes more skilled. It is 

 always best to prepare a number of slides from each 

 specimen, as some of them may fail to show the bacilli. 



The simplest and quickest method of staining is that 

 of Gabbet, and it requires but two solution, which may be 

 preserved for months. The cover glass, prepared and 

 dried in the usual way, is placed for two minutes in a 

 solution of 1 part of fuchsin in 100 parts of a 5 per cent 

 solution of carbolic acid, and 10 parts of absolute alcohol. 

 It is best to warm this solution. The cover glass is next 

 removed from this solution, rinsed in water, and placed 

 for one minute in a solution of 2 parts of methylin blue 

 to 100 parts of a 25 per cent solution of sulphuric acid. 

 It is again rinsed in water, then in alcohol; and dried 

 and mounted in balsam. The preparations made by this 

 method are very beautiful and permanent. 



The method which I employ is that of Pittion and 

 Roux. With this, more time is required, and more skill 

 in manipulation; but when skillfully used, the bacilli are 

 larger and more distinct than by any other procedure. 

 Three solutions are used, and all should be fresh except 

 the first. Sol. a is 10 parts of fuchsin in 100 parts of ab- 

 solute alcohol. Sol. h, 3 parts liq. ammon. in 100 parts 

 distilled water. Sol. c, alcohol 50, water 30, nitric acid 

 20, aniline green to saturation ; dissolve the color in 

 alcohol, then add the water and next the acid. 



To use, take of a 1 part and of & 10 parts, heat until 

 vapor appears, and float cover glass in usual way for 

 about two minutes, then rinse in distilled water, and 

 place in solution c until the red color disappears, then 

 wash and mount. It takes some experience to know just 

 how much to decolorize. 



The tubercle bacilli are distinctly recognized by their 

 red staining. With a good specimen and careful stain- 

 ing by this method the bacilli appear as large under a 



