320 APPENDIX 



changing the fluid if it becomes violet. (Golgi. Nerve-endings 

 in muscle and tendon.) The specimen is perhaps best mounted 

 in 1 p.c. arsenic acid, but it may be mounted in glycerine. 



Gold chloride is chiefly used for nerve-endings in the cornea, 

 in muscle and in skin. 



Cornea : strong acid should not be used ; methods i. a, i. c, 

 iii. give good results ; the cornea may be either mounted at once 

 in formic glycerine, or hardened in alcohol and cut. 



Muscle. Methods iv. and v. give the most constant results. 

 If the muscle is to be teased, it is perhaps best to cut out a 

 small piece with scissors, and to tease it with glass or platinum 

 needles whilst it is in the gold chloride. Whole muscles treated 

 by the formic acid method can be squeezed between slides in 

 formic glycerine, and teased out in this, or sections may be cut 

 with the freezing microtome. It is not as a rule advisable to 

 pass the muscle through alcohol or to mount in balsam, since 

 this causes too much shrinking. 



Skin is generally best treated by the formic acid method ; 

 using 25 p.c. formic acid after the gold chloride, thoroughly 

 washing, hardening in alcohol and cutting sections (cp. p. 212, 

 nose of mole). If the epidermis is not too thick, methods i. 6 

 and iii. may be used. 



Gold chloride is also used to colour cells (cp. p. 66, cartilage ; 

 p. 72, cornea). 



