120 HJEMATEIN AND OTHER OUGANIC STAINS. 



made up in two separate bottles, each containing half of 

 the alcohol and of the acid, and one containing besides all 

 the calcium chloride, the other all the haematein and all the 

 aluminium chloride ; equal quantities being taken from each 

 when required for staining. 



With certain objects this solution does not penetrate well, 

 the stain being confined to their superficial parts. This may 

 be remedied by acidifying the solution, or, which is better, 

 by leaving the objects for some time before staining in acid 

 alcohol. Anyway, objects ought NOT to have an alkaline re- 

 action. If these precautions be taken, it will not be necessary 

 to use acid for washing out. For some objects also (e. g. 

 Hydroida) the penetrating effect is enhanced by diluting the 

 solution with one third vol. of glycerin, or by increasing the 

 proportion of aluminium chloride up to about eight times 

 that of the haematein. 



This solution is not recommended as giving as good results 

 as haemaluin, as a stain it is distinctly inferior ; and Mayer 

 is of opinion that no alcoholic haematein solution can be made 

 to give as precise a stain as the aqueous solutions, for he 

 holds that the watery nature of the menstruum is of itself of 

 a beneficial effect so far as regards the quality of the stain. 

 He recommends it merely as a substitute for Kleinenberg's 

 (in cases in which an alcoholic haematem stain seems indi- 

 cated), as being convenient, easy to prepare, and constant in 

 its effects, none of which qualities belong to Kleinenberg's 

 formula (see below, 184). 



183. MAYER'S Nitrate of Ammonia Haematein Stain (Mitth. 

 a. d. Zool. Stat. zu Neapel, 10, 1, 1891, p. 183, note) ; HENKING 

 (Zeit. f. wiss. Mik., viii, 3, 1891, p. 340) has proposed for this 

 the name of Haemammon). Haemalum, 10 c.c. ; 70 percent, 

 alcohol, 10 c.c. ; nitrate of ammonia, 5 grms. Dissolve ; let 

 the solution stand overnight for the excess of alum to crystal- 

 lise out, and filter. 



Very good for small objects (Mayer has not tried large 

 ones), but does not give so good a stain as hasmalum ; so 

 that, of course, its only raison d'etre is that, like haemacalcium, 

 it is an alcoholic solution. 



184. Kleinenberg's Hsematoxylin (Quart. Journ. Mic. Sci., Ixxiv, 

 1879, p. 208). Prepare a saturated solution of calcium chloride in 70 per 



