SECTION ONE 



Formula: 



Potassium dichromate 2-5% aqueous 100 ml. 

 Mercuric chloride . . . . • • 5 gin- 

 Glacial acetic acid . . . . . . 5 ml. 



N.B. — The acid should not be added until the fixative is 

 required for immediate use. 



Technique: 



Immerse slices of tissue in the fluid for six to twenty-four hours 

 according to the nature of the material and the thickness of the 

 slices. Wash in running water for twelve to twenty-four hours; 

 then transfer to 80% alcohol. 



Remarks: 



Unsuitable for Mitochondria. Suitable for Mallory's connec- 

 tive tissue stain; for demonstration of Muscle, Fibrin, Haemo- 

 fuscin, Purkinje cells, etc. 



(b) DEHYDRATION, CLEARING, EMBEDDING, 



SECTIONING, ETC. 



CELLOIDIN METHOD FOR EMBEDDING TISSUES 



For preserving the relations of cell layers of different con- 

 sistency, as are contained in the eye; for large objects; 

 for pieces of central nervous system ; and for hard tissues 



such as decalcified bone. 



Solutions required: 



A. Celloidin 8% 



Celloidin flakes . . . . • • 25 gm. damped 



with absolute alcohol* 

 Absolute alcohol . . . . , . 150 ml. 

 Ether . . . . . . . . 163 ml. 



*Note: This may be obtained in 25-gm. bottles, 

 ready damped with absolute alcohol. 



17 



