STAINING OF SPORES. 153 



to be held by its edge with the forceps, and its surface 

 covered with Loeffler's alkaline methylene-blue solu- 

 tion. It is then held over the Bunsen flame until the 

 fluid boils; it is then removed, and after a few seconds 

 is heated again. This is continued for about one min- 

 ute, after which it is washed off in water and dipped 

 five or six times in alcohol containing about 0. 2 to 0. 3 

 per cent, of hydrochloric acid. This is rinsed off in 

 water and the preparation is now stained for from eight 

 to ten seconds in aniline-water fuchsin solution (Koch- 

 Ehrlich solution), and finally again washed in water. 

 By this method the spores are of a blue color and the 

 body of the cell red. 



By another process the cover-slip is floated, bacteria 

 down, upon the surface of freshly prepared Koch- 

 Ehrlich solution of fuchsin contained in a watch-crys- 

 tal. This is then held by its edge with the forceps about 

 2 cm. above a very small flame of a Bunsen burner, 

 care being taken that the flame touches only the centre 

 of the bottom of the crystal. After a few seconds the 

 crystal is elevated gradually until it is about 6 to 8 cm. 

 above the flame, then it is slowly moved down to the 

 flame again, and this up-and-down movement is con- 

 tinued until the staining-fluid begins to boil. As soon 

 as a few bubbles have been given off it is held aside for a 

 minute or two, when the process of heating is repeated. 

 When the boiling begins the crystal is held aside again 

 for a minute or two. The crystal is heated in this way 

 for about five or six consecutive times. When the fluid 

 has stood for about five minutes after the last boiling 

 the preparation is transferred, without washing in water, 

 into a second watch-crystal containing the following 

 decolorizing solution: 



