CHAPTER XX 

 OTHER STAINS AND COMBINATIONS 



416. Kernschwarz (Platner, Zeit. wiss. Mik., iv, 1887, p. 350), 

 A black liquid on sale by Griibler. Mayer {Grundziige, Lee & 

 Mayer, 1st ed., p. 202) finds that it contains iron, combined with 

 some gallic acid. Lee used it as follows : 



Sections are fixed on slides and treated with Kernschwarz until the 

 required depth of stain is obtained, which will be from a few minutes 

 to twenty-four hours, according to the material. 



There is obtained a black or neutral tint stain, which is either a pure 

 chromatin stain, or at the same time a plasma stain. If overstaining 

 should have occurred, the stain is easily differentiated by means of any 

 weak acid, either in water or alcohol. Platnkr took alkalies, preferably 

 carbonate of lithia, for differentiation. 



It may be well, if a good plasma stain has been obtained, to afterstain 

 for twenty-four hours with safranin, followed by differentiation in either 

 neutral or acid alcohol, and clove oil. The stain is perfectly permanent 

 in balsam, and is stated to be a good one for preparations that it is 

 desired to photograph. 



Lee recommends this stain which is safe and easy. The combination 

 with safranin gives a better chromatin stain than safranin alone. 



417. Brazilin, the colouring matter of Brazilian redwood or Pernam- 

 buco wood, has been recommended by Eisen (Zeit. wiss. Mik., xiv, 1897, 

 p. 198) and Hickson (Nature, Ixii, 1900, p. 589, and Quart. Journ. Mic. 

 Sci., 1901, p. 469). Maykr {Grundziige, p. 203) finds that, in alum 

 solution, it gives a stain similar to that of haematein, but much weaker. 



Iron-Brazilin (Hickson, Quart. Journ. Alter. Sci., xliv, 1901, 

 p. 470) is better. Sections are mordanted for one to three hours 

 in 1 per cent. sol. of iron alum in alcohol of 70 per cent, (made 

 by dissolving 1 grm. of the salt in 23 c.c. of water, warm, and 

 adding 77 c.c. of 90 per cent, alcohol after cooling), rinsed with 

 alcohol, and put for three to sixteen hours into 0-5 per cent. sol. 

 of Brazilin in alcohol of 70 per cent. 



418. Orchella (Orseille), see Wedl (Arch. path. Anat., Ixxiv, p. 143) 

 and FoL (Lehrb., p. 192), and early editions of this work. 



419. Orcein (Israel, Virchow's Archiv, cv, 1886, p. 169 ; and 

 Prakticum der path. Hist., 2 Aufl., Berlin, 1893, p. 72) is a dye 

 obtained from the lichen, Lecanora parella (tinctoria), and is not 

 to be confused with orcin, another derivative of the same lichen. 

 It is said to unite in itself the staining properties of the basic and 

 acid stains, and also the combination of two contrast colours. 

 Israel stains sections in a solution containing 2 grm. of orcein, 



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