854 CHAPTKH xxix. 



removed, and should be divided into lengths with a saw whilst 

 wet. The 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 perfectly 

 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 moistened 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 

 lithographic 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. Mile., x, 1893, p. 171) grinds and polishes on 

 stones of graduated fineness. 



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



ROSE (Anal. 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 be combined with Golgi's impregnation. 



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

 the following: Sections of osseous or dental tissue should 

 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 



