H^IMATEIN (H^IMATOXYLIN) STAINS. 185 



make a very dilute stain ; and even then care should be taken not to leave 

 objects too long in the fluid. It is an extremely powerful stain. 



BITSCHLI (Unters. ilb. mikroscopische Schdume u. das Protoplasma, 

 etc., 1892 ; Zeit. f. wiss. Mik., ix, 2, 1892, p. 197) recommends, under the 

 name of " acid haematoxylin," solution of Delafield very strongly diluted, 

 and with enough acetic acid added to it to give it a decidedly red tint. 

 This gives a sharper and more differentiated nuclear stain than the usual 

 solution. 



245. Ehrlich's Acid Haematoxylin (Zeit. f. wiss. Mile., 1886, 

 p. 150). 



Water 100 c.c. 



Absolute alcohol ..... 100 ,, 



Glycerin 100 



Glacial acetic acid . . . . 10 



Haematoxylin 2 grms. 



Alum in excess. 



Let the mixture ripen in the light (with occasional admission of air) 

 until it acquires a dark red colour. It will then keep, with constant 

 staining power, for years, if kept in a well- stoppered bottle. Sections are 

 stained in a few minutes. It is stated that the solution ia also very 

 appropriate for staining in bulk, as over-staining does not occur. 



Of all the old formulae 1 have tried, this is the one that has given me 

 the sharpest chromatin stain. 



MANN (Zeit. f. wiss. Mik., xi, 4, 1895, p. 487) makes ap this stain with 

 an equal quantity of haeinatein instead of haematoxylin. 



MATES (Grundzuge, p. 154) finds that this is too much, and makes the 

 mixture overstain ; 0*4 grm. of hsematein is quite enough. 



246. MAYER'S Haemacalcium (Mitth. Zool. Stat. Neapel, x, 

 1, 1891, p. 182). Haemateiii (or haemateate of ammonia, 

 '234, 235), 1 grm. ; chloride of aluminium, 1 grm. ; chloride 

 of calcium, 50 grms. ; glacial acetic acid, 10 c.c. (or common 

 acetic acid, 20 c.c.) ; 70 per cent, alcohol, 600 c.c.. Rub up 

 finely together the first two ingredients, add the acid and 

 alcohol, dissolve either cold or with heat ; lastly add the 

 chloride of calcium. 



A reddish -violet liquid. If the objects stain in too red a 

 tone they may be treated with a aulution (of about 2 per 

 cent.) of chloride of aluminium in 70 per cent, alcohol, or 

 with a 0'5 to 1 per cent, solution of acetate of soda or potash 

 in absolute alcohol ; but washing with neutral alcohol will 

 generally suffice. 



The solution is not perfectly stable, but in course of time 

 (Mitth. a. d. Zool. Stat. Ntapel, x, 3, 1892, p. 499) turns blue 



