250 PRESERVATION MEDIA. 



be prepared in the same way. The most beautiful of all 

 these mounting media is the solution of damar in xylol. Heat 

 is not necessary to make the solution. 



Minute directions (which I think unnecessary) for pre- 

 paring a working solution are given by MAETINOTTI in Zeit. f. 

 iviss. Mik., iv, 2, 1887, p. 156, and in Malpighia, ii, 1888, 

 p. 270 ; cf. also Journ. Roy. Mic. Soc., 1889, p. 163. 



FLEMMING, PFITZNER, and a writer signing C. J. M., all 

 employ a mixture of benzol and turpentine (see Arch. mik. 

 Anat.j xix, 1881, p. 322 ; Sci. Gossip, 1882, p. 257 ; Journ. 

 Roy. Mic. Soc. [N.S.], iii, 1883, p. 145 ; Morphol. Jahrb., vi, 

 1880, p. 469; Journ. Roy. Mic. Soc. [N.S.], ii, 1882, p. 583). 



MAX FLESCH notes hereon (Zool. Jahresber. f. 1880, p. 51) 

 that at Wiirzburg the ordinary dammar varnish of arists is 

 employed. 



JAMES (Engl. Mech., 1887, p. 184; Journ. Roy. Mic. Soc., 

 1887, p. 1061) also gives some, I think, superfluous formulae 

 for damar solutions; and still another new method is given, 

 op. cit., 1890, p. 680. 



A formula for a damar and mastic medium is given by 

 SQUIRE, in his Methods and Formulas, &c., p. 84. 



421. Balsam-Damar. It has been recommended to mix equal volumes 

 of benzol balsam and turpentine damar, but this medium seems to me 

 superfluous. 



422. Colophonium. A solution of colophonium in turpen- 

 tine has been recommended by Kleinenberg. I find it works 

 very pleasantly. The palest kind of colophonium should of 

 course be taken. 



This medium sets very slowly, so that ample time is afforded 

 for arranging objects in it. Kleinenberg warns against the 

 employment of absolute alcohol as a solvent; the prepara- 

 tions are beautiful at first, but soon become spoiled by the 

 precipitation of crystals or of an amorphous substance. 



The turpentine solution keeps perfectly limpid, gives very 

 good definition, and is altogether so excellent a medium that 

 I am surprised that it is not more used. It should be recom- 

 mended to beginners. 



423. Venice Turpentine for Mounting (VossaLER, Zeit. f. wiss. 

 Mik., vi, 3, 1889, p. 292, et seq.). Vosseler strongly recommends this 

 medium as having considerable advantages over Canada balsam or damar. 



