292 PRACTICAL HISTOLOGY. [XXVI. 



A good plan is to clarify an unstained section with clove-oil con- 

 taining eosin. The cells are stained red, and form a sharp contrast 

 to the blue. A watery solution such as picro-carmine cannot be 

 used to stain the cells, as it rapidly extracts the blue from the bile- 

 channels. 



11. Fresh Liver-Cells. Scrape the surface of a fresh liver, and 

 .observe in normal saline. 



(H) Observe the pale, nucleated, polygonal, or cubical faintly- 

 granular cells, of ten containing small refractive oil globules. Often 

 the cells are broken up. There are always many blood-corpuscles 

 in the field (fig. 94). 



ADDITIONAL EXERCISES. 



- 12. Connective-Tissue Stroma. With a camel's-hair brush pencil away as 

 many as possible of the hepatic cells from a thin section of any properly 

 hardened liver. The connective-tissue network may be afterwards stained 

 with picro-lithium carmine or eosin. 



13. Intralobular Connective Tissue. Various methods have been adopted 

 to show the existence of connective tissue within the liver lobules and between 

 its cells. The following methods reveal a network of black fibrils continuous 

 with the interlobular tissue, and traversing as a network the substance of the 

 lobule. This method is also useful for showing the trabeculse of the spleen, 

 and the fibrillar structure in the splenic corpuscles and lymph-glands generally. 



(a.) Bohm's Method. 



(1. ) Harden small pieces (.5 cm. cube) in 0.5 per cent, chromic acid (2 



days). 



(2.) Silver nitrate .75 per cent. (3 days). 

 (3.) Wash in distilled water, harden, cut, and mount in balsam. 



(&.) Oppel's Method is available for liver hardened in alcohol. 



(1.) Yellow chromate of potash 10 per cent, (i day). 



(2.) Silver nitrate, large volume, .75 per cent. (2 days). Much silver 



chromate is formed, so that the silver must be frequently 



renewed. 

 (3.) Wash in water, harden in alcohol, sections, balsam. 



By either method the liver cuts readily on freezing, but hand sections, I 

 think, are best. Paraffin embedding is not to be recommended. 



14. Bile-Capillaries (Bohm). Golgi's method. 



(1.) Harden (3-4 days) small pieces of the liver (.5 cm. cube) in 



Bichromate potash solution (3 per cent.) . 4 vols. 

 Osmic acid (i per cent.) .... I vol. 



(2.) Place in 0.75 per cent, silver nitrate (2 days). 

 (3.) Wash in distilled water, harden in alcohol. 

 (4.) Sections. Balsam. 



