CHAPTER XXXIII. 449 



danted with copper acetate, for twelve to twenty-four hours in a solution 

 of 3 to 4 c.c. of Gallein in 100 c.c. of water with 20 of alcohol and three 

 drops of a concentrated solution of sodium carbonate. Sections are 

 differentiated by the method of Weigert, or Pal. Nerve-fibres red. A 

 second stain with methylene blue may follow (best after differentiating 

 with potassium permanganate). Similarly SCHROTTER (Centrabl. allg. 

 Path., xiii, 1902, p. 299). 



867. SCHROTTER (Neurol. Gentrbl., xxi, 1902, p. 338) also stains 

 sections for two to three hours in a 5 per cent, solution of sodium 

 sulphalizarinate, to which a few drops of 5 per cent, oxalic acid (enough 

 to give an orange tint) are added, then differentiates until no more 

 colour comes away in sodium carbonate solution of ^^ strength, and 

 mounts in balsam. Myelin red, on a colourless ground. 



868. Toluidine Blue and Methylene Blue. HARRIS (Philadelphia Med. 

 Journ., i, 1898, p. 897) stains sections (of material hardened as for 

 Weigert's stain) for several hours in a 1 per cent, solution of toluidine 

 blue in 1 per cent, borax solution, and differentiates in saturated aqueous 

 solution of tannic acid. Similarly, but with methylene blue, in a com- 

 plicated way FRAENKEL (Neurol. Oentrbl., xxii, 1903, p. 766). 



BING and ELLERMANN (Arch. Anat. Phys., Phys. Abth., 1901, p. 260) 

 harden in 9 parts of acetone to 1 of formol, cut without imbedding, 

 stain for five to ten minutes in saturated methylene blue solution, and 

 put for one or two into saturated solution of picric acid. 



869. Other Modifications or Similar Methods. FLECHSIG, Arch. Anat. 

 Phys., Phys. Abth., 1889, p. 537 ; BREGLIA, Ztschr. wiss. MiJcr., vii, 

 1890, p. 236; Rossi, ibid., vi, 1889, p. 182; MERCIER, ibid., vii, 1891, 

 p. 480 ; HAUG, ibid., p. 153 ; WALSEM, ibid., xi, 1894, p. 236 ; ROBERT- 

 SON, Brit. Med. Journ., 1897 (1), p. 651. 



STRONG (Journ. Comp. Neur., xiii, 1903, p. 291) finds copper bichro- 

 mate (of 2 to 3 per cent.) the best mordant ; and that the mordanting is 

 best done before bringing into celloidin. After staining, he treats for 

 half a minute with 0-25 per cent, osmic acid and differentiates as Pal. 



K. KOCH (Berl. Klin. Wochenschr., li, 1914, p. 422) makes sections by 

 the freezing method of formalin material imbedded in gelatine, and 

 after staining with Weigert's iron haematoxylin, differentiates by Pal's 

 method, and mounts in glycerin jelly. 



870. MARCHI'S Method (for Degenerate Nerves) (Riv. sperim. 

 Fren., xii, 1886, p. 50). Small pieces of nervous tissue are hardened 

 for a week in Mailer's solution, and then put for a few days into a 

 mixture of 2 parts of Miiller's solution and 1 part of 1 per cent, 

 osmic acid. Sections are cut, best without imbedding, and mounted 

 in balsam. The myelin sheaths of normal nerve fibres take a 

 yellowish-brown colour, those of degenerated fibres a black one. 



This process, therefore, gives positive images of the degenerated 

 elements, Weigert's process only giving negative ones. 



For a critical review of this method and its modifications, see 

 M. 29 



