CH. VII.-\ PARAFFIN SECTIONING. 167 



§ 278. Staining the Sections with an Alcoholic Dye. — With an 

 alcoholic stain like hydrochloric acid carmine, remove the slide from 

 the alcohol and add the stain directly after draining the slide. Do not 

 allow the slide to become dry, for that would probably ruin the tissue. 

 Wash away the stain with 67 r /o alcohol then dehydrate with 95 '/o alco- 

 hol and clear and mount in balsam as described below. 



§ 279. Staining with an Aqueous Dye. — Wash away the alcohol 

 b} 7 plunging the slide bearing the sections into a jar of water and mov- 

 ing it around a moment. Then add the stain to the sections with a 

 pipette and allow the slide to rest horizontally on the bars of the waste 

 bowl (Fig. 134) or preferably immerse the slide in a jar of the stain 

 ('§ 264). The sections are usually well stained in from 1 to 10 min- 

 utes when they should be thoroughly washed with water. 



§ 280. Staining with a General Dye. — If it is desired to give a 

 general stain after the nuclear dye, carmine stained preparations can be 

 stained half a minute or more with picric-alcohol (§ 315) and the hem- 

 atoxylin stained specimens with eosin (§ 305). It usually takes only 

 10 to 20 seconds for this. Then wash away the stain with 67 % alcohol. 



£ 281. Dehydration of the Stained Sections. — Place the slide 

 with the stained sections in a jar of 95% alcohol for a few minutes or 

 wave it around for a minute or two and the preparation will be ready 

 for clearing and mounting. 



§ 282. Clearing the Sections. — Drain off the alcohol and add a 

 drop or two of clearer (Carbol-turpentine (§ 303). If any whiteness 

 or cloudiness remains the sections were not sufficiently dehydrated. 

 Complete the dehydration by washing away the clearer with 95 f / f; alco- 

 hol and soaking the slide a few minutes in a vessel of the same. 



§ 283. Mounting in Balsam. — For this the clearer is drained away 

 by standing the slide nearly vertically on some blotting paper or by 

 putting it in the funnel of the waste bowl. The balsam is then placed 

 on the sections and the cover-glass added or the balsam is spread on 

 the cover-glass. 



For labeling and cataloging and storing the preparations see § 291- 



295- 



