VIIl] RAPID HARDENING. STAINING IN BULK 63 



The stain with Delafield's hsematoxylin is less restricted to 

 the nuclei than that with acid-haematoxylin, on this account the 

 former is commonly best when one stain only is used. The stain 

 may be further restricted to the nuclei by leaving the tissue 

 when stained in acid alcohol (70 p.c. alcohol containing 1 p.c. 

 hydrochloric acid) for half-a-day to a day. 



Hsemalum has been recommended as a hsematoxylin stain on 

 the ground that it stains more quickly and does not overstain. 



After staining with eosin the tissue must not be left long in 

 alcohol, as this removes the eosin stain ; the eosin instead of 

 being added to 95 p.c. alcohol, may be added to absolute alcohol, 

 the tissue left in this for a day, and then passed to the clearing 

 agent. 



Of the carmine stains, borax carmine is perhaps the best ; 

 carmalum, alum carmine, and picrocarmine are also used. 

 These solutions need not be diluted. 



Picric acid may be used as a second stain after carmine or 

 hscmatoxylin, the method is the same as that given for eosin in 

 the text 



