TOOLS AND METHODS OF WORK 



35 



edge of the cover slip with the forceps to imbed it firmly into the ''tacky" 

 ring (Fig. 21, A and B). If this be done carefully no difficulty will be 

 experienced with air bubbles. A litde of the fluid may have been 

 pressed out of the cell by this operation, this must be absorbed with 

 filter paper, and a fresh ring of cement applied to seal up the junction 

 of cover and cell. The preparation must now be allowed to dry 



A. 



B. 



Fig. 21. 



-A. Method of placing cover slip on a fluid mount. B. Turntable in action and 

 cover slip being pressed into position. C. Mounting plate on turntable carrier. 



thoroughly for some days, when it should be rung with old gold size, and 

 while this is still moist a protective cap (Fig. 20, A, 1-2) must be placed 

 over the top of the cell, and a fresh stout ring of gold size applied over 

 the entire structure, and the preparation again put away to dry. A ring 

 of "zinc oxide" made with the proper proportion of " old gold size " 

 may now be applied ; this must over-lap all the previous rings, and if 

 the cements be properly made and properly applied the preparation will 

 stand for a lifetime. 



