292 CHAPTER XXI. 



length of the side of the cover-glass. The wire is heated in 

 a spirit lamp, plunged into the cement, some of which ad- 

 heres to it, and then brought down flat upon the slide at the 

 margin of the cover. The turpentine distributes itself evenly 

 along the side of the cover, and hardens immediately, so that 

 the slide may be cleaned as soon as the four sides are 

 finished. It is claimed for this cement that it is perfectly 

 secure, very handy, and never runs in. The cement sets 

 hard in a few seconds. 



465. Colophonium and Wax (KEONIG, Arch. f. mik. Anat. t 

 1886, p. 657; Jour n. Roy. Mic. Soc., 1887, p. 344). Seven 

 to nine parts of colophonium are added piecemeal to two 

 parts of melted wax, the whole filtered and left to cool. For 

 use, the mass is melted by placing the containing vessel in 

 hot water. The cement is not attacked by water, glycerin, 

 or caustic potash. 



466. APATHY'S Cement for Glycerin Mounts (Zeit. f. wiss. 

 Mik., vi, 2, 1889, p. 171). Equal parts of hard (60 C. melt- 

 ing-point) paraffin and Canada balsam. Heat together in a 

 porcelain capsule until the mass takes on a golden tint and 

 no longer emits vapours of turpentine. On cooling, this 

 forms a hard mass, which is used by warming and applying* 

 with a glass rod or brass spatula. One application is enough. 

 The cement does not run in, and never cracks. 



467. Paraffin. Temporary mounts may be closed with 

 pure paraffin, by applying it with a bent wire, as described 

 464. 



468. Canada Balsam, or Damar. Cells are sometimes made with 

 these. They are elegant, but in my experience are not reliable for per- 

 manent mounts. 



469. Amber Varnish. As above mentioned, BEHRENS finds 

 this cement to possess an extreme tenacity. That used by 

 him may be obtained from Grubler & Hollborn. 



470. Amber and Copal Varnish (HEYDENBEICH, Zeit. f. wiss. 

 Mik., 1885, p. 338). Extremely complicated; may be ob- 

 tained from Ludwig Marx, at 110, Moskowskaja Sastawa, 



