USED SLIDES AND COVER-SLIPS 23 



2. Heat over a Bunsen flame and allow the acid 

 to boil gently for twenty minutes. 



NOTE. A few pieces of pipe-clay or pumice may be placed in 

 the beaker to prevent the "spurting" of the chromic acid. 



3. Turn the cover-slips out into a flat glass dish and 

 wash in running water under the tap until all trace 

 of yellow colour has disappeared. During the wash- 

 ing keep the cover-slips in motion by imparting a 

 rotatory movement to the dish. 



4. Wash in distilled water in a similar manner. 



5. Wash in rectified spirit. 



6. Transfer the cover-slips, by means of a pair of 

 clean forceps, previously heated in the Bunsen flame 

 to destroy any trace of grease, to a small beaker of 

 absolute alcohol. 



Drain off the alcohol and transfer the cover-slips, 

 by means of the forceps, to a wide-mouthed glass pot, 

 containing absolute alcohol, in which they are to be 

 stored, and stopper tightly. 



NOTE. After once being placed in the chromic acid, the cover- 

 slips must on no account be touched by the fingers. 



Used Slides and Cover =slips. Used slides with the 

 mounted cover-slip preparations, and cover-slips used 

 for hanging-drop mounts, should, when discarded, be 

 thrown into a pot containing a 2 per cent, solution of 

 lysol. 



After immersion therein for a week or so, even the 

 cover-slips mounted with Canada balsam can be readily 

 detached from their slides. 



Slides. 



1 . Wash the slides thoroughly in running water. 



2. Boil the slides in water to which "sapon" has 

 been added, for half an hour. 



3 . Rinse thoroughly in cold water. 



4. Dry and polish with a dry cloth. 



