BOHMER'S HSEMATOXYLIN. 123 



4 grms. of haematox. crist. dissolved in 25 c.c. of strong alcohol. 

 Leave it exposed to the light and air in an unstoppered 

 bottle for three or four days. Filter,, and add 100 c.c. of 

 glycerin and 100 c.c. of methylic alcohol (CH 4 0). Allow the 

 solution to stand until the colour is sufficiently dark, then filter 

 and keep in a tightly stoppered bottle. 



This solution keeps well, it may be said to keep for years. 

 It is well to allow it to ripen for at least two months before 

 using it. 



This famous solution is certainly one of the best hsematoxy- 

 lin stains yet published. It is extremely powerful, and when 

 properly used very precise. For staining, enough of the 

 solution should be added to pure water to make a very dilute 

 stain ; and even then care should be taken not to leave objects 

 too long in the fluid. 



BUTSCHLI (JJnters. ub. mikroscopische Schdume u. das Proto- 

 plasma, &c., 1892; Zeit. f. wiss. Hik., ix, 2, 1892, p. 197) 

 recommends, under the name of " acid haematoxylin," solu- 

 tion 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. 



186. Bohmer's Hsematoxylin (Arch. f. mik. Anat., iv, 1868, 

 p. 345; Aerzt. IntelligenzbL, Baiern, 1865, p. 382). Make (A) 

 a solution of haematox. crist. 1 part, alcohol (absolute) 12 

 parts, and (B) alum 1 part, water 240. For staining, add two 

 or three drops of A to a watch-glassful of B. 



The staining solution ought not to be made up at the moment 

 of using, but should be made up beforehand and allowed to 

 ripen for some days (Mayer says at least two months). The 

 alcoholic solution of haematoxylin may be kept in stock ; it 

 becomes brown, but does not lose its properties. 



Washing out may be done with a 0'5 per cent, solution of 

 alum in water, or with acids if desired. 



This formula gives perhaps a finer stain than Delafield' s, 

 but, on account of the uncertainty of the ripening process, 

 is not so certain in its results. 



187. Ranvier's Hsematoxylin (Comptes rend. Ac. Sc., 2 sem., t. xcv, 

 p. 1375). If solutions prepared according to the formula of Bohiner be kept 

 for some weeks they will be found to furnish an abundant precipitate. 



