STAINING FLUIDS. 23 



the sections should be washed in water until every trace of ox- 

 alic acid is removed. .Sections thus prepared may be mounted 

 in balsam or dammar. Connective- tissue substances are blue, 

 while the nuclei are red. The osseous lamellae of bone are 

 blue, the cells in the lacunae red, while the marrow is apple- 

 green. 



Picro-carmine (Miller's). Add one part of a saturated so- 

 lution of picric acid to two parts of the 15-graih borax carmine 

 solution (Arnold's). The epithelium of the glands and the 

 muscles are stained yellow, while the nuclei of the cells and the 

 connective tissues acquire the carmine color. Sections should 

 remain in the picro-carmine solution for about twenty -four 

 hours. Next they are washed quickly in water, then in alcohol, 

 after which they are transferred to the oil of cloves. (For Ran- 

 vier's method of making picro-carmine, see the chapter upon 

 the Histology of the Nervous System.) 



Hcematoxylin solution (Boehmer' s). Dissolve 20 grains of 

 hsematoxylin in one-half an ounce of absolute alcohol ; then 

 dissolve 2 grains of alum in an ounce of water. Some drops of 

 the first solution are added to the second, which, after a short 

 time, becomes a beautiful violet. It improves after keeping for 

 a few days, and should always be filtered before using (Thin). 



Hcematoxylin solution (Kleinenburg' s). First make a satu- 

 rated solution of the chloride of lime in seventy per cent, alco- 

 hol, and add alum to saturation. 



Then make a saturated solution of alum in seventy per 

 cent, alcohol. Add the first to the second in the proportion of 

 one to eight. To the mixture add a few drops of a saturated 

 solution of hsematoxylin in absolute alcohol (Thin). 



Hcematoxylin solution (Miller's method). Take a pint bot- 

 tle, as in the former process, fill with water, and add about an 

 ounce of common extract of logwood in coarse powder. Allow 

 this to remain in a warm place for twenty -four hours, with 

 occasional stirring. After the expiration of this time add pow- 

 dered commercial alum until the liquid changes from the 

 muddy brown color given by the logwood to a brilliant purple. 



The alum is to be added until no change is produced. An 

 excess of the salt will do no harm. Add about f. I j. of alcohol, 

 and after decanting or filtering it is ready for use. One 

 may omit the alcohol at this stage, and evaporate to dryness 

 as in the borax-carmine process. The powder thus obtained is 



