3i8 



CLEANING SLIDES AND COVER-GLASSES 



[Ch. X 



Fig. 188. Micrometer Calipers for Measuring 

 the Thickness of Slides and Cover-glasses. 



(From the Catalogue of the Brown & Sharpe Manu- 

 facturing Company). 



alcohol added. The 

 covers remain in this 

 until needed. In wip- 

 ing use the precau- 

 tions given with slides 



(§ 49°)- 

 Test for the proper 



cleanliness as for slides 

 (§ 490), and remember 

 the advantage of heat- 

 ing \he cover-glass in 

 a Bunsen or alcohol 

 flame to render it cap- 

 able of receiving a smooth and even film of blood or other aqueous 



liquid. 



§ 494. Cleaning large cover-glasses. — For serial sections and 

 especially large sections, large 

 quadrangular covers are used. 

 These are to be put one by one 

 into a cleaning mixture as for 

 the smaller covers and treated 

 in every way the same. In wip- 

 ing them one may proceed as for 

 the small covers, but special 

 care is necessary to avoid break- 

 ing them. It is desirable that 

 these large covers should be 

 thin — not over 0.15-0.20 mm., 

 otherwise high objectives can- 

 not be used in studying the 

 preparations. 



§ 495. Measuring the thick- 

 ness of cover-glasses. — It is of 

 great advantage to know the ex- 

 act thickness of the cover-glass 

 on an object; for, (a) in study- 



Fig. 189. Measurer for Slides and 

 Cover-glasses. 



(Modified from the figure in Zeiss 

 Catalogue) . 



Cover A cover-glass between the jaws (j)- 



J Jaws between which the object to 

 be measured is placed. 



H Hand which points to the gradua- 

 tions on the face indicating the fractions 

 of a millimeter or inch that represents the 

 thickness of the object between the jaws. 



L Lever by which the jaws are opened 

 to receive the object. 



