10 HARDENING ASD FIXING REAGENTS. 



(not Water) and preserved in 90 p. c. Alcohol. Picric Acid 

 solutions dissolve out calcareous deposits. 



(x.) FICRO SULPHURIC ACID (Kleinenberg). 



Saturated aqueous solution of Picric Acid, 100 cc. ; pure 

 Sulphuric Acid, 2 cc. ; filter ; to each 100 cc. of nitrate add 

 300 cc. of Distilled Water. 



As in Kleinenberg's formula four-fifths of the Picric Acid is thrown 

 out of solution, the same final result can be obtained by the following : 



Saturated Solution of Picric Acid, 20 cc. ; Distilled Water, 

 380 cc. ; Sulphuric Acid, 2 cc. 



Especially useful for the rapid fixing of very soft tissues, 

 as sarcoma and myxoma ; also for preserving embryoes. It 

 is used for fixing and preserving the earth-worm. 



Tissues are placed in the fluid from 3 to 12 hours ; they 

 are then washed in 70 p. c. Alcohol, and finally placed in 

 90 p. c. Alcohol. 



Carmine is the best stain to use after this solution ; but if 

 Hsematoxylin be used, the sections must first be placed in 

 a solution of Carbonate of Lithium, and then washed in 

 Water. 



(xi.) ACETATE OP COFFER. 



Acetate of Copper, 1 grm. ; Distilled Water, 200 cc. ; Glacial 

 Acetic Acid, 1 cc. ; Glycerine, 200 cc. ; Corrosive Sublimate, 

 3 grms. 



This solution is especially useful for fixing and mounting 

 green Algse. 



