[249] 



Zbc niMcroscopc au^ Ibow to ITlec it 



By V. A. Latham, F.R.M.S. 



Part XV. 



Practical Hints on Histology. 



Special Methods for Examination of the Spinal Cord, 



Brain, etc. (continued.) 



Spinal Cord, Fibres of (SchiefFordecker's method). 



PLACE a piece of fresh cord, with its membranes removed, foi 

 about a month in Miiller's solution ; then wash for about 

 twenty-four hours with water, and afterwards place in alcohol. 

 AVash the sections in water for one or two days, and stain with 

 palladium chloride or gold chloride. Wash with water, and pass 

 through absolute alcohol and oil of cloves into balsam. 



Palladium Chloride. —This agent is used to demonstrate the 

 longitudinal fibres (therefore, longitudinal sections must be cut), a 

 solution of I — 10,000 strength is taken. The sections should 

 remain in it till light brown (about three hours). 



Gold Chloride.— Used for transverse sections. Strength, 

 I to 5,000 or 10,000; time, i to 3 hours. Wash the sections well in 

 water, and place in acetic acid, h to i per cent., for twenty-four 

 hours. Then mount as described above. 



Picro-Carminate of Soda and Palladium Chloride.— Place the 

 sections for one to three minutes in a i to 300 or 600 solution of 

 palladium ; rinse in water ; throw for eight to ten minutes into a 

 cold saturated solution of picro-carminate of soda. Mount in 

 dammar. 



Staining Isolated Ganglion Cells.— Macerate small pieces in a 

 small quantity (just sufficient to cover them) of Ranvier's alcohol 

 for several days. Take some small fragments of grey matter, and 

 well shake them in a test-tube with a little water. Then add a 

 little glycerine and a few drops of the concentrated solution of 

 picro-carminate of soda, and set the whole aside for one or two 

 days. Decant, and to the red deposit, which is now composed of 

 stained ganglion-cells, add one or two drops of glycerine, and 



