266 CHAPTER XIX. 



Hasmatein or Hsematoxylin Combinations. 



379. Haematoxylin and Picric Acid. See 281. 



380. Haematoxylin and Eosin or Benzopurpurin ( 295). 

 Objects may be stained with haematoxylin (either in the mass 

 or as sections) and the sections stained for a few minutes in 

 eosin. I think it is better to take the eosin weak, though it 

 has been recommended (STOHK, see Zeit.f. wiss. Milt., i, 1884, 

 p. 583) to take it saturated. Either aqueous or alcoholic 

 solutions of eosin may be used. 



HICKSON (Quurt. Journ. Mic. Sci., 1893, p. 129) gives the 

 following instructions for staining sections on the slide : 

 One hour in a strong solution of eosin in 90 per cent, alcohol, 

 wash with alcohol, and stain for twenty minutes in a weak 

 solution of haematoxylin. 



This method is most particularly recommendable for 

 embryological sections, as vitellus takes the eosin stain ener- 

 getically, and so stands out boldly from the other germinal 

 layers in which the blue of the haematoxylin dominates. 



See also LIST (Zeit.f. wiss. Mik., ii, 188-% p. 148) ; BUSCH 

 (Verh. Berl. Pliys. Ges., 1887); GIEKKE (Zeit. f. wis*. Mik., 

 i, 1884, p. 505). 



It should be noted that sections should be very well washed 

 before being passed from eosin into haematoxylin or the reverse, 

 as eosin very easily precipitates .haematoxylin. 



381. RENAUT'S Haematoxylic Eosin (FOL'S Lehrbuch, p. 196). A very 

 complicated glycerin mixture, which acts so slowly that it may take weeks 

 to stain, and, I think, superfluous. 



EVEBAED, DEMOOE and MASSAKT (Ann. Inst. Pasteur, vii, 1893, p. 166) 

 prepare a similar mixture as follows : A solution is made with 1 grm. of 

 eosin, 25 grms. of alcohol, 75 of water, and 50 of glycerin. Then 20 grms. 

 of alum are dissolved by the aid of heat in 200 grms. of water, the solution 

 is filtered, and after twenty-four hours there is added to it 1 grm of hsema- 

 toxylin dissolved in 10 grms. of alcohol. This solution is allowed to stand 

 for eight days, then filtered again, and combined with an equal volume of 

 the eosin solution. 



382. Haematein and Congo. -See 294. 



