TOLU BALSAM. 209 



Boy. Mie. 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. 



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

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

 superfluous. 



401. Colophonium. A solution of colophonium in turpentine 

 has been recommended by Kleinenberg. I find it works very 

 pleasantly. The palest kinds 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 preparations 

 are beautiful at first, but soon become spoiled by the precipi- 

 tation 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. 



402. Venice Turpentine (see the quotation in Zeit. f. wiss. Mile., iii, 

 3, 1886, p. 400). 



403. Copal Varnish. I have seen tissues very instructively 

 mounted in this medium, which is probably worthy of further 

 study. " Berry's Hard Finish/' which is an easily obtainable 

 copal varnish, has been highly praised for mounting purposes 

 (see Journ. Roy. Mic. Soc., 1887, p. 1064). 



404. Photographic Negative Varnish (for mounting large sections 

 without cover-glasses) (see WEIGERT, Zeit. f. wiss. Mile., iv, 2, 1887, p. 209). 



405. Styrax and Liquidambar (see Journ. Roy. Mic. Soc., 1883, p. 

 741 ; ib. 1884, pp. 318, 475, 655, and 827 ; and the places there quoted. 

 Also Bull. Soc. Beige de Mic., 1884, p. 178 ; and FOL, Lehrb. p. 141). 



406. Tolu Balsam (see Zeit.f. wiss. Mik., iv, 4, 1887, p. 471). 



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