212 OTHER STAINS AND COMBINATIONS. 



380. Orcein (ISRAEL, V i rcho w ' s Archiv, cv, 1886, p. 169 ; and Prakti- 

 cum der path. Hist., 2 Aufl., Berlin, 1893, p. 72) is a dye obtained from 

 the lichen, Lecanora parella, 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 grms. of orcein, 2 grms. of glacial acetic acid, and 100 c.c. of distilled 

 water, washes in distilled water, and passes rapidly through absolute 

 alcohol to thick cedar oil, in which the preparations remain definitely 

 mounted. Nuclei blue, protoplasm red. 



See also " Connective Tissues " in Part II, and LAURENT, Zeit. wiss. 

 Mile., xiii, 1896, p. 302 ; RUZIOKA, ibid., xiv, 1898, p. 455 ; and WOLFF, 

 ibid., xix, 1903, p. 488. 



381. Purpurin, see EANVIER'S Traite technique, p. 280 ; DUVAL'S 

 Precis de Technique histologique, p. 221 ; and GEENACHER'S formula in 

 Arch. mik. Anat., xvi, 1879, p. 470. A very weak stain. 



382. Indigo. Indigo is employed in histology in the form of solutions 

 of so-called indigo carmine, or sulphindigotate of soda or potash. The 

 simple aqueous solution gives a diffuse stain, but is of use when employed 

 in conjunction with carmine. See below. 



Thiersch's Oxalic Acid Indigo-Carmine (see Arch. mik. Anat., i, 1865, 

 p. 150). 



383. Other Vegetal Dyes. See early editions. Those recommended 

 by CLAUDIUS (Zeit. wiss. Mik., xvii, 1900, p. 52) are superfluous. 



Carmine Combinations . 



384. Seller's Carmine followed by Indigo-Carmine (Am. Quart. Mic. 

 Journ., i, 1879, p. 220). Stain in borax-carmine, wash out with HC1 

 alcohol, wash out the acid, and after-stain in an extremely dilute alcoholic 

 solution of indigo -carmine (2 drops of saturated aqueous solution added 

 to an ounce of alcohol and filtered). 



I find this method gives good results with sections, but not if it be 

 attempted to stain in bulk. 



385. Merkel's Carmine and Indigo-Carmine in One Stain (MERKEL, 

 Unters. anat. Anst. Rostock, 1874 ; Month. Mic. Journ., 1877, pp. 242 

 and 317). 



Also NORRIS and SHAKESPEARE, Amer. Journ. Med. Sci., January, 

 1877 : MERKEL, Mon. Mic. Journ., 1877, p. 242 ; MARSH, Section Cutting, 

 p. 85 ; BAYERL, Arch. Mik. Anat., xxiii, 1885, pp. 36, 37 ; MACALLUM, 

 Trans. Canad. Instit., ii, 1892, p. 222 ; Journ. Roy. Mic. Soc., v, 1892, 

 p. 698. 



386. MAYER'S Carmalum (or Hsemalum) and Indigo-Carmine in 

 One Stain. MAYER (Mitth. Zool Stat. Neapel, xii, 1896, p. 320) 

 obtains very good results by taking a solution of 0-1 grm. of indigo- 

 carmine in 50 c.c. of distilled water, or 5 per cent, alum solution, and 

 combining it with from 4 to 20 volumes of carmalum or haemalum. 



387. Carmine and Picro-Indigo-Carmine (RAMON Y CAJAL, Rev. 



