OTHER STAINS AND COMBINATIONS. 265 



374. Carmine and Picro-Indigo-Carmine (CAJAL, Rev. de 

 Cienc. wed., 1895 ; CALLEJA, Rev. trim. Microgr., ii, 1897, 

 p. 101 ; Zeit. f. wiss. Mik., xv, 3, 1899, p. 323). For use 

 after a carmine stain, CAJAL takes a solution of 0'25 gramme 

 of indigo-carmine in 100 grammes saturated aqueous solution 

 of picric acid. Stain (sections) for five to ten minutes, wash 

 in weak acetic acid, then in water, then remove the excess 

 of picric acid with absolute alcohol, clear and mount. Em- 

 ployed in this way, the indigo is said to give a sharper plasma 

 stain than without the picric acid. 



375. Carmine and Anilin Blue (or Bleu Lumiere, or Bleu 

 de Lyon) (DCVAL, Pr<r/.s- de technique microxcopique, 1878, 

 p. 225) . Stain with carmine " in the ordinary way ; ' 

 dehydrate, and stain for a few minutes (ten minutes for a 

 section of nerve-centres) in an alcoholic solution of aniliii 

 blue (ten drops of saturated solution of aniliii blue soluble 

 in alcohol to ten grammes of absolute alcohol, for sections of 

 nerve-centres). Clear with turpentine, without further 

 treatment with alcohol, and mount in balsam. 



Eecent authors recommend, instead of aiiilin blue, bleu de 

 Lyon, dissolved in 70 per cent, alcohol acidulated with acetic 

 acid (MAURICE and SCHULGIN), or bleu lumiere. which has 

 hardly any effect on nuclei. 



The solutions of both these colours should be extremely 

 dilute for sublimate material, but strong for chrom- osmium 

 material. It is possible to use them for staining in bulk. 



BAUMGARTEN (Arch. f. mik. Anat., xl, 1892, p. 512) stains 

 sections (of material previously stained in borax-carmine) for 

 twelve hours in a 0'2 per cent, solution of bleu de Lyon in 

 absolute alcohol, and washes out for about half that time 

 before mounting in balsam. He recommends the process for 

 cartilage and nerve-centres. 



376. Carmine and Malachite Green. MAAS (Zeit. f. wiss. Zool.. 1, 

 4, 1890, p. 527; Zeit. f. iviss. Mile., viii, 2, 1891, p. 205) recommends 

 borax -carmine followed by weak alcoholic solution of malachite green, with 

 a final washing out with stronger alcohol, see also 302. 



377. Carmine and Picro-nigrosin (PIANESE) (see Journ. Roy. Mic. 

 8oc., 1892, p. 292). 



378. Carmine and Picric Acid. See 5 281. 



