STAINING FLUIDS. 233 



2oz. ; Sp. vim rect., |oz. Dissolve the carmine in the 

 ammonia, boil for a few seconds, add the water, filter, and 

 finally add the glycerine and spirit, and keep in a stop- 

 pered bottle. Beale says : " Let the excess of ammonia 

 pass off ; " but this is unnecessary, as the excess is very 

 slight. This solution reduced, with eleven times its 

 bulk of water, produces good results in from 12 to 48 

 hours. 



Borax carmine, as follows : (1) carmine, |dr. ; (2) 

 borax, 2dr. ; (3) distilled water, 4oz. Bub 1 and 2 

 together in a mortar and gradually add the water; 

 let them stand in a warm place for 24 hours, after 

 which pour off the supernatant fluid, and the solution 

 is ready for use. 



There are stains which, being acted upon by light, 

 get rapidly darker, and become opaque, and reach a 

 stage when they are utterly useless. 



Nitrate of silver darkens by exposure ; it is used 

 in a half per cent, watery solution. Specimens to 

 be acted upon should be washed in distilled water to 

 remove every trace of sodium chloride, and then steeped 

 in the silver solution for some two or three minutes r 

 after which they should be again washed until 

 they cease to turn milky; then place them in gly- 

 cerine and expose them to the action of light until they 

 assume a dark brown colour, when they should be 

 mounted in glycerine or glycerine jelly. 



By means of this stain the endothelial cells of the 

 lymphatics, blood-vessels, &c., and the nodes of Ban- 

 vier, in medullary nerves, are rendered visible. Sec- 

 tions of any of these may subsequently be stained by 

 logwood or carmine. 



Several methods have been adopted for staining with 

 gold chloride. Dr. Klein's and Mr. Schafer's are among 

 the best. 



1. Dr. Klein's method of showing the nerves of the 

 cornea is as follows ; Bemove the cornea within fifteen 

 minutes of death ; place it in a half per cent, chloride 

 of gold solution for half an hour or an hour ; wash in 

 distilled water, and expose to the light for a few days ; 

 in the meantime occasionally change the water. Then 



