SPECIAL MICROSCOPIC TECHIQUE. 



alkali completely. After washing in water the pieces of tissue 

 are stained in alum carmine for some hours, and mounted in 

 glycerin. 



25. Sections of fixed and hardened muscle may be stained 

 in various ways. The most useful are the following : Heiden- 

 hain's iron-ha3inatoxylm, Ehrlich's triple stain, Kolossow's 

 osmic acid treatment, etc. 



5. NERVOUS TISSUE. 



26. Isolated multipolar ganglion cells from the spinal cord 

 are obtained as follows : small pieces of gray matter of the an- 

 terior horn are placed for from thirty -six to forty-eight hours 

 in 33 per cent, alcohol. They are then stained in picro- 

 carmine for twenty-four hours and examined in glycerin. 



27. Nissl's method for staining nerve cells : material fixed 

 in alcohol and imbedded in paraffin is cut into thin sections, 

 which are fixed on slides by the water method. They are 

 then placed in a solution of 15 parts of methylene-blue and 7 

 parts of Venetian soap in 4000 parts of water, at a temperature 

 of 65-70 C. until steam arises, or, according to van Gehuchten, 

 at a temperature of 35-40 C. for from five to six hours. They 

 are then differentiated in a mixture of 1 part of anilin oil and 

 9 parts of 96 per cent, alcohol. If the white matter is de- 

 colorized, while the gray matter is still blue, the sections are 

 passed through xylol into xylol-dammar. 



28. Medullated nerve fibres may be studied in the fresh 

 condition, and stained with methylene-blue. 



29. Medullated nerve fibres may be fixed in the following 

 way : a piece of fresh nerve is fixed for from three to six hours 

 in 0.5 per cent, osmic acid solution or in Flemming's fluid. 

 It is then washed in water, hardened in alcohol, and stained 

 for twenty-four hours in safranin. After being differentiated 

 in alcohol the nerve is dehydrated and cleared in oil of cloves. 

 The nuclei of Schwann's and Henle's sheaths are colored red, 

 while the nodes of Kanvier and the Schmidt- Lantermann's lines 

 are plainly visible. Such nerves may also be sectioned. 



30. Non-medullated nerves, which are to be treated in the 



