KERNSCHWARZ. 133 



is a black liquid of unknown composition, prepared in Russia. 

 It may be obtained from Griibler (address 94). Sections 

 (sections only, this colour behaving like safranin, for instance) 

 may be stained in a tolerably strong dilution of the concen- 

 trated liquid, and washed out (it may be for some hours) in 

 an alkaline aqueous liquid. Dilute ammonia will do, but it is 

 better to take a not quite saturated solution of carbonate of 

 lithium (you may take a saturated solution, and dilute it with 

 three, four, or more volumes of water). The result is a 

 nuclear stain in the cytological sense ; nuclear figures of 

 division are stained deeply, resting chromatin less deeply or 

 not at all, cytoplasm unstained or faintly grey. A peculiarity 

 of this stain, on which much stress was laid by Platner in his 

 first announcement of the colour, is that it stains also the 

 Neberikern (which safranin and the other anilins do not do 

 when employed in the usual way) . 



After some experimentation I feel bound to say that I do not think Kern- 

 schwarz has the importance seemingly claimed for it by Platner. It cer- 

 tainly stains the Nebenkern, but it does so less rather than more effectively 

 than haematoxylin, not to mention Henneguy's permanganate-safranin 

 method ( 106), or Flemrning's orange method, 258. Platner seems to 

 have come to this conclusion himself, his latest work on the Nebenkern 

 making no further mention of Kernschwarz, and having been done apparently 

 entirely with hsematoxylin. And, as a nuclear stain, Kernschwarz seems to 

 me inferior to hsematoxylin, to say nothing of the chromatin-staining anilins. 

 Only in the event of its being found available for staining in the mass (which 

 may be possible, though I have not succeeded in it) will Kernschwarz, as it 

 seems to me, be found to be an important reagent. 



209. Other Stains. Litmus, red cabbage, bilberry juice ("myrtillus"), 

 black currant juice (" ribesine "), and walnut juice (" nucina ") have been 

 recommended by Lawson Tait, Lavdowsky, Fol, and Leon respectively. 

 They do not appear to call for further notice here. 



