240 CHAPTER XIX. 



See also the Micro graphic Dictionary, and A. F. STANLEY 

 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 



Aquse . . . . . . 5'0 



To which after twelve hours are added 



Glycerin! ...... 5'0 



Sol. aquosa acid, corbal. (5*100) . . . 1OO 



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

 litt.}. Solution of gum arabic of the consistency of 

 glycerin, strained, and one eighth volume of glycerin and 

 one twentieth of formol gradually incorporated. Sets hard. 



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

 (Bid. 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 

 haematoxylin 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 twenty- 

 five degrees 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. 



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

 miers 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 



