NUCLEAR STAINS. 25 



It is five to ten times stronger in Hsematoxylin than 

 other solutions, and the greater part of the Alum (85 p.c.) 

 crystallizes out on cooling. 



When this solution is employed sections must be immersed 

 for a shorter time, or it must be more diluted than the other 

 solutions. 



(y.) KLEINENBERG'S H-ffiMATOXYLIN. 



The peculiarity of this solution is that it contains a quantity 

 of Chloride of Calcium, which, when staining in bulk, sets up 

 diffusion currents between the alcohol in the material to be 

 stained and the alcoholic staining solution, so- enabling the 

 latter to penetrate more rapidly. 



Great differences exist in the formulae given for this solution. It would 

 appear from the Quarterly Journal of Microscopic Science, 1879, p. 208, that 

 Kleinenberg himself latterly used the following process : 



"Prepare a saturated solution of Calcium Chloride in 70 p. c. Alcohol, 

 with the addition of a little Alum; after having filtered, mix one 

 volume of this with 6 to 8 volumes of 70 p. c. Alcohol. At the time of 

 using the liquid pour into it as many drops of a concentrated solution of 

 Hsematoxylin in Absolute Alcohol as are sufficient to give the required 

 colour to the preparation, of greater or less intensity according to desire." 



In an older formula, given by Balfouf and Foster in their " Elements of 

 Embryology," and copied into various text-books, a saturated solution of 

 Alum in 70 p. c. Alcohol is used instead of 70 p. c. Alcohol alone, for 

 diluting the strong Chloride of Calcium solution ; but as 70 p. c. Alcohol 

 only dissolves 1 in 1000 of Alum, this serves no useful purpose. It is also 

 directed that the Calcium Chloride solution should be saturated with Alum ; 

 but this is quite impracticable. Double decomposition takes plfwe.to^such 

 an extent that when saturated with Alum the liquid actually solidifies 

 from separatioCof Sulphate of Lime. 



As Kleinenberg' s above formula is still very indefinite in regard to the 

 quantity of Alum used, and as the extent of the decomposition will vary 

 with the fineness of the Alum powder, the following modification 

 is ^recommended as giving 'an exact and uniform result. * - 



Hsematoxylin, 2J grms. ; Crystallized 

 grms. in 10 cc. of Distilled Water; Alum, 3 grms. in 16 

 cc. of Distilled Water ; Rectified Spirit, 240 cc. 



