CELL-SPACES OF CARTILAGE. 93 



highly refracting corpuscles lying loosely in their 

 cell-spaces. 



At the thinnest parts of all the sections cavities 

 may he observed in the matrix which are devoid of 

 cartilage-cells; these having dropped out in the pro- 

 cess of preparation. 



Preparation 4. These cavities or cell-spaces of 

 cartilage may he also demonstrated by the same 

 method as was employed to show the cell-spaces of 

 connective tissue, viz., treatment with nitrate of 

 silver and subsequent exposure to the light. For 

 this purpose a fresh joint should be opened, and the 

 articular end of one of the bones (preferably a convex 

 one) removed with the saw r or bone-forceps. The 

 end thus removed is rinsed in distilled water and 

 then quickly transferred to nitrate of silver solution 

 (J per cent.), in which it is allowed to remain three 

 minutes. It is then again rinsed in water, and if 

 necessary gently brushed with a camel-hair pencil 

 to remove adhering silver precipitates ; after which 

 it is placed in a beaker of weak spirit and exposed 

 to sunlight. "When thoroughly browned, sections 

 are made from the surface with a razor wetted with 

 spirit, and are placed in water (care being taken that 

 they become completely immersed), after which they 

 may be mounted in glycerine. 



Some of the sections should be taken from near 

 the edge of the cartilage and mounted on a separate 

 slide. These should show 7 the branched cell-spaces, 

 which present a transition to the much more ramified 

 spaces of the connective tissue of the synovial mem- 

 brane. 



The cells themselves which occupy the spaces are 

 not shown, for, as in silvered tissues generally, the 

 cell-protoplasm remains absolutely unstained ; indeed, 

 it is at first sight difficult to believe that the rounded 

 cavities which are seen really contain cartilage- cells. 

 But their nuclei may be brought into view r by stain- 

 ing with logwood, subsequently the matrix being 

 colored by the nitrate of silver. As before men- 



