BACILLUS ANTHRACIS. 19 



6. Staining with picrocarmine and Gram's method. 



(a) Place the sections in picrocarmine 20 to 30 

 minutes. 



(ft) Wash in water to which a few drops of hydro- 

 chloric acid have been added. 



Then pass the sections through the process described 

 under (5) with the exception of counterstaining with 

 eosin. 



Inoculation of Mice or Guinea Pigs Subcutaneously 

 with Bacillus Anthracis. (Class Demonstration.) 

 The animal is placed in a holder or held by an 

 assistant. The hair is clipped from the point of inoc- 

 ulation, (root of tail in mouse, inner side of thigh in 

 guinea pig). The skin at this point is then washed 

 with 1:1000 solution of bichloride of mercury. With a 

 sterile scissors a small snip is made through the skin. 

 With a platinum loop a drop of 48 hours broth culture 

 of Bacillus anthracis is introduced and pushed well up 

 under the skin. The point of introduction is then 

 lightly seared with a heated glass rod, 



