ILEMATEIN (ILTCMATOXYLIN) STAINS. 159 



or the mordant becomes turbid, then stains with the hsematoxylin in 

 the same way. The whole process takes about ten minutes. 



HELD (Arch. Anat. Phys., Anat. Abth., 1897, p. 277) adds to the 

 staining bath a very little of the iron-alum solution until a scarcely 

 perceptible precipitate is produced. A dangerous practice. I find it is 

 not even safe to add a little of an over-used bath (supra). 



FRANCOTTE (Arch. Zool. Exper., vi, 1898, p. 200) mordants with tar Irate 

 of iron, MALLORY (Journ. Exper. Med., v, 1900, p. 15) with chloride. 



243. Iron Hsematoxylin (BiJTSCHLi, Unters. uber mikroskopische 

 Sch flume u. das Protoplasma, etc., 1892, p. 80). Sections treated with a 

 weak brown aqueous solution of ferric acetate, washed with water, and 

 stained in 0'5 per cent, aqueous solution of hsematoxylin. A stain of 

 extraordinary intensity, used by Biitschli for sections, 1 /* in thickness, 

 of Protozoa. 



244. Weigert's Iron Hsematoxylin Mixture (Zeit. wiss. Mile., xxi, 

 1904, p. 1). Mix one part of a 1 per cent, solution of hsematoxylin in 

 alcohol of 96 per cent, with one of a solution containing 4 c.c. of liq. 

 fi'rri sesquichlor., 1 c.c. of officinal hydrochloric acid (sp. gr. T124) and 

 95 of water. The mixture may be kept for some days (until it begins to 

 smell of ether), but is best used fresh. Stain sections for a few minutes ; 

 no differentiation is necessary. 



For an earlier process of WEIGERT'S (Allg. Zeit. Psychiatr., 1894, p. 

 245) see last edition. 



MOREL and BASSAL (Journ. Anat. Phys., xlv, 1909, p. 632) stain in 

 bulk in Weigert's mixture with the addition of 1 c.c. of 4 per cent, solu- 

 tion of acetate of copper. 



245. JANSSENS' Iron Haematoxylin ("Hematoxyline noire"; La 

 Cellule, xiv, 1897, p. 207). A similar mixture to that of DELAFIELD, 

 ferric alum being taken instead of ammonia alum, the rest as in Dela- 

 field's. A progressive stain, nuclear : for yeast cells. 



246. HANSEN'S Iron Heematoxylin (Zeit. wiss. Mile., xxii, 1905, p. 55). 

 A solution of 10 grms. ferric alum in 150 c.c. water is added to a 

 solution of 1'6 grin, haematoxyliii in 75 c.c. water, the mixture heated 

 to boiling-point and cooled without access of air. Filter before use. 

 To get a pure nuclear stain, add dilute sulphuric acid. 



247. Aluminium Haematein (Alum Haematoxylin) Generalities. 

 The mordant and dye are generally combined in a single 



staining bath, giving a progressive stain. The stain is in 

 different tones of blue or red according to the composition of 

 the staining solution. Neutral or alkaline solutions give a 

 blue stain ; acid solutions give a red one. In order to get a 

 blue stain in preparations that have come out red through 



