i88 



PARAFFIN SECTIONING 



\CH. VII 



drop of the albumen on the center of a slide and with a clean finger spread the 

 albumen over the slide, wiping off all that is possible. Finally beat or tap the 

 slide with the end of the finger. This will make a very thin (it cannot be too 

 thin) and even layer. 



The sections are extended and dried as described in $ 289. When the sections 

 are thoroughly dry they are in optical contact with the slide and have a shining 

 appearance when looking on the back of the slide. When the sections are dry 

 coat them with $% collodion made as follows. Take ^ gram of soluble cotton, 

 put it into a bottle and add 60 cc. of 95% or absolute alcohol, and 40 cc. of sul- 

 phuric ether. Coat the sections with a soft camel's hair brush. The collodion 

 should dry in a minute or less. If one uses too much ether in this fixing collo- 

 dion, the paraffin will be partly dissolved and will look moist for a long time. 

 The slight excess of alcohol will obviate any such difficulty. 



FIG. 158. A slide holder and 

 bottle for containing the same (Mix, 

 Journal of Applied Microscopy, vol. 

 /, 1808, p. 160.) 



FIG. 759. Slide holder with the 

 bail hinged so that it may be turned 

 aside in inserting or removing the 

 slides. 



When the collodion is dry place the slide in benzin or xylene to dissolve 

 the paraffin (see $ 291). If the sections are not extended on water, they may be 

 put directly on the albumenized sides, pressed down with the finger and coated 

 with collodion. This is much more rapid, but. does not get rid of the fine folds. 

 (See Dr. Agnes Claypole Trans. Amer. Micro. Soc. 1894, p. 66, 127.) 



\ 291. Removing the Paraffin. Immerse the slide in a vessel of xylene or 

 benzin. This will dissolve the paraffin. An hour will usually suffice. One can 



