370 CONNECTIVE TISSUES. 



medulla should then be driven out from the central canal by means 

 of a jet of water ; spongy bones should be treated as follows : 



An epiphysis having been removed, together with a small portion 

 of the diaphysis, a piece of caoutchouc tubing is fixed by a ligature 

 on to the cut end of the diaphysis, and the free end of the piece of 

 tubing adapted to a tap through which water flows under pressure ; 

 they are then put to macerate for several months, the liquid being 

 changed from time to time. As soon as all the soft parts are per- 

 fectly destroyed, the bones may be left to dry. 



Thin sections may then be cut with a saw and prepared by rubbing 

 down with pumice-stone. Compact pumice-stone should be taken 

 and cut in the direction of its fibres. The surface should be mois- 

 tened with water and the section of bone rubbed down on it with 

 the fingers. When both sides of the sections have been rubbed 

 smooth in this way, another pumice-stone may be taken, the section 

 placed between the two, and the rubbing continued. As soon as 

 the section is thin enough to be almost transparent it is polished by 

 rubbing with water (with the fingers) on a Turkey hone or litho- 

 graphic stone. Spongy bone should be soaked in gum and dried 

 before rubbing down (but see VON KOCH'S copal process and 

 EHRENBAUM'S colophonium process). 



SCHAFFER (Zeit. wiss. Mik., x, 1893, p. 171) grinds and polishes on 

 stones of graduated fineness. 



For the process of WEIL for bones and teeth see 180. 



ROSE (Anat. Anz., vii, 1892, pp. 512-519) follows Koch's process. He 

 penetrates first with a mixture of cedar oil and xylol, then with pure 

 xylol, and imbeds in solution of Damar in chloroform or xylol. The 

 method can bs combined with Golgi's impregnation. 



FANZ (Anat. Record, xiv, 1918, p. 493) employs sand or carborundum 

 paper of different grades of coarseness for grinding, using the back or 

 smooth side of a piece of sandpaper for polishing the section. He 

 recommends shellac in preference to balsam for attaching the section 

 to the glass slip. 



WHITE (Journ. Roy. Mic. Soc., 1891, p. 307) recommends the 

 following : Sections of osseous or dental tissue stlould be cut or 

 ground down moderately thin, and soaked in ether for twenty- 

 four hours or more. They should then be put for two or three days 

 into a thin solution of fuchsin in collodion, then into spirit to harden 

 the collodion. After this they are ground down to the requisite 

 thinness between two plates of old ground glass, with water and 

 pumice powder, and mounted, surface dry, in stiff balsam or styrax, 

 care being taken to use as little heat as possible. Lacunae, canaliculi, 

 and dentinal tubuli are found infiltrated by the coloured collodion. 



