504 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



The solution has then acquired a deep orange colour. Filter through 

 filter-paper. This mother-solution is employed by adding 1 vol. to 

 20 vols, of alum solution (potash alum 50 grm., distilled water 1000 c.cm). 

 The mixture immediately turns violet, and should be used as soon as 

 possible. 



Method of Emploijment. — The sections having been freed from paraffin 

 by means of xylol, alcohol, and distilled water are treated with the 

 haemalum solution for two minutes (15 minutes if the chromatin is 

 specially required to be differentiated). Wash in tap- water, and counter- 

 stain with a solution of 1 grm. of eosin (alcoholic frangaise) in 100 c.cm. 

 absolute alcohol (one or two minutes). Wash and dehydrate in the usual 

 manner and mount. 



(5) Mounting, including: Slides, Preservative Fluids, etc. 



Arsenious Acid-glycerin-gelatin (" Arsenious Jelly ") Method of 

 Preserving and Mounting Pathological Specimens with their 

 Natural Colours.* — S. Delepine describes the following method for 

 mounting specimens : — 



A. Fixing Solution. — Formal (commercial) 40 p.c. solution, 1 00 c.cm. ; 

 water, 900 c.cm. To which may be added, sulphate of soda, 20 grm. 



The specimens are left in this solution for from three days to two weeks, 

 according to thickness. A piece of tissue h in. thick is sufficiently fixed 

 and hardened in two days. (For a time the author used a larger pro- 

 portion of formaldehyde, 5 p.c. and even 8 p.c, but found that for most 

 purposes a 4 p.c. solution was sufficient.) 



B. Alcohol (80 to 90 p.c). — The specimens are left in this fluid until 

 the colour has returned as nearly as possible to its original tint. A few 

 hours are generally sufficient to obtain a satisfactory and permanent 

 superficial effect. 



C. Ari^enious Acid-glycerin Fluid. — Arsenious acid solution (made by 

 boiling an excess of arsenious acid in water for two hours, and allowing 

 the fluid to stand for twelve hours), 400 c.cm. ; pure glycerin, 600 c.cm. 



The specimens are transferred from the alcohol to this solution, where 

 they must be kept for one or two days at least. They may without 

 serious disadvantage remain in it for two or three weeks, if the solution 

 does not cause marked shrinkage. 



Z). Arsenious Acid-glycerin Jelly (formula for about 8 litres). — 

 1. Coignet's gelatin (Gold label), 425 grm. ; arsenious acid, saturated 

 water solution (see G), 1500 c.cm. The dry gelatin, thoroughly cleansed, 

 is added to the hot arsenious acid solution, in which it should be entirely 

 dissolved in less than | hour. 2. Hot arsenious acid jelly (see 1), 

 1925 c.cm. (say 2000) ; pure glycerin (hot), 5760 c.cm. (say 5800)- 



The two are mixed together and allowed to cool to about 20° C, 

 then the white of six eggs and their broken shells are added and mixed 

 thoroughly with the mass. The mixture is brought again to nearly 

 boiling-point to coagulate the albumin, and is maintained at this 

 temperature for two hours. The hot fluid is strained through flannel 



* Museums Journal, xiii. (1914) pp. 322-5. 



