ON STAINING FLUIDS, AND STAINING. 85 



solution becomes clear. If this fluid when used 

 overstains yellow, add acetic acid, if red, add 

 ammonia. 



3. PiCRO-LiTHiuM CARMINE. 



Dissolve 2J grammes of carmine in 100 c.c. of a 

 saturated solution of lithium carbonate, add 2 to 

 3 c.c. of a saturated solution of picric acid. Filter. 



All preparations stained with picro-carmine may 

 be mounted in xylol balsam, but Farrant's medium 

 is preferable. 



PICRO-CARMINE AND EOSIN. (Lang's Formula.) 



Mix 50 parts of a 1 per cent, picro-carmine 

 solution with 50 parts of a 2 per cent, aqueous 

 solution of eosin ; after prolonged immersion for 

 from twelve hours to forty-eight, or even seventy- 

 two hours wash out the picrin in repeated 

 changes of alcohol, until the eosin ceases to colour 

 the spirit. 



This is a very fine double stain. 



Mount in xylol balsam. 



STJLPH-INDIGOTATE OF SODA. 



Make a saturated solution of sulph-indigotate of 

 soda in distilled water, and to each ounce thereof 

 add from 3 to 6 minims of rectified alcohol, filter, 

 and keep in a closely stoppered bottle. It is better 

 to make small quantities of this fluid as required, 

 as it does not keep very long. This stain is suit- 

 able only for fibrous tissues skin, scalp, hair, and 

 for epitheliomatous growths. 



Mount in xylol balsam. 



