26 NUCLEAR STAINS. 



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Dissolve the Calcium Chloride and the Alum in their re- 

 spective quantities of water, by the aid of heat ; mix the solu- 

 tions and immediately dilute with the Eectified Spirit ; after 

 an hour filter and add the Hsematoxylin. 



The above quantities make a good working solution. Any 

 dilution which is required must be made with some more of 

 the filtered liquid to which Hrematoxylin has not been added. 



Crystallized Chloride of Calcium is preferred to the ordinary anhydrous 

 variety, on account of its greater purity : the anhydrous Chloride is 

 always alkaline. "Whichever be used, a saturated solution in 70 p. c. 

 Alcohol will contain about 40 p. c. of CaCls. 



As in the finished solution, the whole of the Aluminium exists as 

 Chloride, it has been proposed to avoid the double decomposition with 

 Alum, by simply adding to the Chloride of Calcium solution a definite 

 quantity of Aluminium Chloride. It is difficult, however, to obtain this 

 latter free from uncombined Hydrochloric Acid, so that the double decom- 

 position process is the best. 



Kleinenberg adds the Heematoxylin just before use. Lee says it is 

 best to add it 24 to 48 hours previous to use, with the additional note that 

 the solution does not keep ; while Stirling says it should be kept for at 

 least a month before it is wanted. 



The solution is principally used for staining in bulk, and as 

 a rule the larger the object the weaker in Haematoxylin 

 should the solution be made to stain slowly and uniformly. 



(vi.) WEIGERT'S HJEMATOXYLIN for the central 

 nervous system. (See p. 48.) 



Haematoxylin, 1 ; Absolute Alcohol, 10 ; Distilled Water, 

 90 ; aqueous solution of Lithium Carbonate (1 in 70), 1. 



(vii.) RENAUT'S GLYCERINE HJEMATOXYLIN. 



Saturate Glycerine with Potash Alum, and to it add drop 

 by drop a saturated solution of Haematoxylin in 90 p. c. 

 Alcohol to form a deeply coloured solution ; let it stand 

 exposed to daylight for at least a week, and filter. 



Both this and the following solution are employed for 



