SOME OTHER HISTOLOGICAL METHODS. 443 



may be left to dry. When dry, they should be of an ivory 

 whiteness, and their surfaces exposed by cutting of a uniform 

 dulness. 



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, ante, 172, and EHKKNBAUM'S colophonium process, 

 173). 



For the process of WEIL for bone and teeth, see 175. 



ROSE (Anat. Anz., vii, 1892, pp. 512 519; Zeit. f. wiss. Mik., ix, 4, 

 1893, p. 506) follows Koch's process. He penetrates first with a mixture 

 of cedar oil and xylol, then with pure xylo!, and imbeds in solution of 

 damar in chloroform or xylol. The method can be combined with Golgi's 

 impregnation. 



WHITE (Jonrn. 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 collodion 

 stained with fuchsiii (made by dissolving the dye in methy- 

 lated spirit, adding the requisite quantity of ether, then the 

 pyroxylin) . The sections are then put 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. Lacuna?, canaliculi, and dentiiial tubuli are found 

 infiltrated by the coloured collodion. 



MATSCHINSKY (Arch. f. mik. Anat., xxxix, 1892, p. 151, and xlvi, 1895, 

 p. 290 ; Zeit. f. iviss. Mik., ix, 3, 1893, p. 353, and xiii, 1896, p. 68) after 

 grinding, impregnates with nitrate of silver. 



