Aqueous Mounting Technics and Ringing Slides 123 



The Two-cover Glass Method 



The material is mounted out of glycerol into glycerol jelly between 

 two cover glasses, one of which is smaller than the other. Clean away 

 excess jelly and air dry overnight. Invert the pair of cover glasses on a 

 drop of resinous medium, such as Permount or Piccolyte, on a slide. 

 This will permanently seal the mount, and it can be treated like any 

 resin mount. 



Ringing Slides 



If the mountant contains a volatile substance like water and the 

 slides are to be rendered relatively permanent, the cover glass must be 

 sealed with a ringing material. Ringing cements are sold by supply 

 houses, such as General Biological's "Turtox Slide Ringing Cement." 

 Others easily obtainable are Duco cement, colorless nail polish, gold size 

 and asphaltum. Lustron 2020 {Monsanto Chemical Corp.) dissolved in 

 xylene can be used. Orange shellac in alcohol can ring a cover glass and 

 then be covered with black asphalt varnish. Prepare the ringing shellac 

 by dissolving flake orange shellac in 95% alcohol. It dissolves slowly, so 

 keep the bottle in a warm place, and shake it occasionally. By adding 1 

 drop castor oil to each oimce of liquid, the ring will not dry out com- 

 pletely. (Needham, 1958) 



Conger {I960) recommends Dentists' Sticky Wax {Kerr Manufactur- 

 ing Co., Detroit, Mich.). It is solid and slightly tacky at room tempera- 

 ture, but flows easilv when melted. It adheres well and does not leak, but 

 will crack off cleanly if frozen with dry ice or liquid air. Good for 

 acetocarmine preparations. 



A firm and reasonably permanent ringing cement is cover glass ce- 

 ment "Kronig" from Riedel-de-Haen AG, Seelze-Hannover, Germany. 

 At present it is not handled by American importers, but it can be pur- 

 chased from George T. Gurr, London. 



For temporary mounts, melted paraffin can be used to ring a cover 

 glass, but it is susceptible to temperature damage and will crack away 

 from the cover. It, therefore, is not recommended for slides subject to 

 hard usage and the passage of time. 



If the cover glasses are round, a turntable rotating on a steel pin or 

 ball bearing facilitates the ringing operation. {Watson and Sons, Lon- 

 don) The turntable spins rapidly and, with the ringing cement on a 

 brush, a neat seal can be made by following concentric guide lines. 



