EXAMINATION AND PRESERVATION MEDIA 229 



499. Hyrax (Dallas Hanna, Journ. Roy. Mic. Soc, vol. 1, 1930). 

 A derivative of naphthalene. Soluble in benzene, xylol, but not in 

 aleohol. Claimed by the inventor not to decompose or crystallise 

 after several years. Refractive index 1-82248. Used for mount- 

 ing diatoms. 



F. J. BiusLEE (Watson's Microscope Record, No. 25, 1932), uses 

 hyrax for diatoms, and finds it more suitable than balsam or styrax. 



499 bis. Dioxan balsam (Gatenby, Biological Technique, 1937). 

 Dioxan balsam appears to be reliable. Mount from dioxan or 

 96 % alcohol. 



