STAINING, PRACTICAL AND THEORETICAL 



CRISTALITE 



Refractive index 1-515 



This synthetic mountant has all the properties of Clearmount 

 except that it dries much more rapidly and is not miscible with 

 alcohol. 



DAMAR XYLOL 



This is an antiquated mountant now apparently little used, not 

 that antiquity in itself is necessarily a fault: in fact a number of 

 mountants, stains and reagents of greater antiquity than damar 

 xylol are still used today and it would be difficult to replace them 

 with satisfactory substitutes. But damar xylol and any other 

 mountant containing gum damar, is unreliable and not to be 

 recommended, particularly today when the microscopist has a 

 variety of excellent and reliable modern synthetic mounting 

 media, such as D.P.X. (Kirkpatrick & Lendrum), Cristalite, 

 Clearmount, Emexel, Michrome mountant and others, from 

 which to choose. No matter how carefully gum damar-containing 

 mounting media are prepared to ensure clear bright solutions free 

 from traces of water, on being kept in stock for any length of time, 

 even in tightly closed bottles, the solutions are liable to become 

 cloudy and unusable, due to adulterants in the raw gum, which 

 defy removal. As long ago as 19 13, Lee stated that after ample 

 experience he was convinced that not one of the gum damar 

 solutions proposed by various authors could be depended on for 

 permanent preservation; that " sooner or later, sometimes after 

 a few weeks or days, or it may be only after months or years, 

 granules make their appearance in mounts." 



D.P.X. 



(Kirkpatrick & Lendrum, 1939, 1941) 



Refractive index I'S^S 



This excellent synthetic mountant, which is colourless and 

 neutral and does not cause fading of stains and on which Cristalite 

 and probably other proprietary synthetic mountants are based, 

 has the added advantage of being one of the least costly of the 



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