Production of Sections 285 



Recapitulation of pages 264-284. 



1. Perfectly fresh and healthy material. 



2. Fix with your utmost ability, but do not overfix. 



3. Wash out fixative, bearing in mind that the choice of 

 a washing fluid must be governed by the fixative used. 



4. Harden. 



5. Dehydrate. If from an aqueous washing solution, 

 then in gradually increasing grades of alcohol. 



6. Semi- clearing fluid. 



7. Clear thoroughly. 



8. Xylol-paraffin bath. 



9. Infiltrate in pure paraffin wax ; do not have the 

 temperature of the oven higher than the melting-point of 

 the paraffin. 



10. Embed the infiltrated object, and cool the wax as 

 quickly as possible. 



11. Prepare the blocks containing the object, and cement 

 to cubes of wood. 



12. Prepare microtome for cutting, orientate the object 

 perfectly, square the block, and cut. 



13. Prepare the slides, stretch the strips of ribbon, and 

 float them into position on the slides in proper sequence ; 

 put away to dry. 



14. Clear away paraffin from sections by heating and a 

 xylol bath. 



15. Alcohol baths. 



16. Staining (not dyeing). 



17. Dehydrating baths. 



18. Clearing in xylol-phenol. 



19. Enclose in xylol-balsam, glycerine jelly, or other 

 medium, and finish. 



NOTE. It is occasionally useful to make a preliminary examination 

 of a spare section. Mounting in clove-oil, in which eosin or other 

 stain has been dissolved, will clear away the paraffin and stain at the 

 same time. Heat will accelerate the action. 



