CHAPTER XIX. 221 



419. Medium of FARRANTS (BEALE, How to Work, etc., p. 58). 

 Picked gum arable 4 ozs., water 4, glycerin 2. See also the Micro- 

 graphic Dictionary, and A. F. STANLEY t KENT, in Journ. Roy. Mic. 



Soc., 1890, p. 820. 



420. Gum and Glycerin Medium (LANGERHANS, ZooL Anzeig., ii, 1879, 

 p. 575). 



Gummi arab. . . . . . . 5-0 



Aquae ........ 5*0 



to which after twelve hours are added 



Glycerin! . . . . . . . 5-0 



Sol. aquosa acid, corbal. (5-100) . . . 10-0 



421. ALLEN'S Gum and Glycerin. Prof. F. J. ALLEN (in litt.). 

 Solution of gum arabic of the consistency of glycerin, strained, and 

 | volume of glycerin and -$ of formol gradually incorporated. Sets 

 hard. 



422. HOYER'S Gum with Chloral Hydrate or Acetate of Potash (Biol. 

 Centralb., ii, 1882, pp. 23, 24). A high 60 c.c. glass with a wide neck 

 is filled two -thirds full with gum arabic (in pieces), and then either a 

 solution of chloral (of several per cent.) containing 5 10 per cent, of 

 glycerin is added or officinal solution of acetate of potash or ammonia. 

 Filter after solution. The solution with chloral is for carmine or 

 hsematoxyrin objects that with acetate for anilin objects. 



423. COLE'S Gum and Syrup Medium. See 183. 



424. APATHY'S Gum and Syrup Medium (see 343). This medium 

 sets very hard and may also be used for ringing glycerin mounts. 



425. FABRE-DOMERGUE'S Glucose Medium (La Nature, No. 823, 

 9 Mars, 1889, supp.). Glucose syrup diluted to 25 of the areometer 

 (sp. gr. 1-1968) 1000 parts, methyl alcohol 200, glycerin 100, camphor 

 to saturation. The glucose is to be dissolved in warm water, and 

 the other ingredients added. The mixture, which is always acid, 

 must be neutralised by the addition of a little potash or soda. It 

 is said to preserve without change almost all animal pigments, but 

 the mounts do not keep indefinitely. 



426. BRUN'S Glucose Medium (from FABRE-DOMERGUE'S Premiers 

 Principes du Microscope, 1889, p. 123). Distilled water 140 parts, 

 camphorated spirit 10, glucose 40, glycerin 10. Mix the water, 

 glucose, and glycerin, then add the spirit, and filter. HENNEGUY 

 informs me that this liquid preserves the colour of preparations 

 stained with anilin dyes, methyl green included. 



427. Levulose is recommended by BEHRENS, KOSSEL u. SCHIEF- 

 FERDECKEB (Das Mikroskop, etc., 1889). It is uncrystallisable, and 

 preserves well carmine and coal-tar stains (hsematoxylin stains fade 



