CHAPTEE^XXXIIl. 461 



871. AZOULAY'S Osmic Acid Methods (Anal. Anz., x, 1894, p. 25). 

 (A) Sections of Miiller material are put for five to fifteen minutes 

 into a solution of 1 : 500 or 1 to 1,000 of oxmic acid, rinsed with water, 

 and put for two to five minutes into a 5 or 10 per cent, solution of 

 tannin, warming them therein over a flame till vapour arises, or in 

 a stove at 50 to 55 C. Wash for five minutes in water, counter- 

 stain with carmine or eosin, and mount in balsam. If the sections 

 are too thick it will be necessary to differentiate by Pal's process, 

 or with eau de Javelle diluted with 50 volumes of water. (B) Material 

 that has been in an osmic mixture (fluids of Flemming, or Marchi, 

 or Grolgi). Sections as before, then tannin bath, warming for three 

 to ten minutes, the rest as before. 



872. HELLER AND GUMPERTZ (Ztschr. wiss. Mikr., xii, 1895, p. 385) 

 give for peripheral nerves, and HELLER (ibid., xv, 1898, p. 495) 

 for central nervous system, the following method. Sections of 

 Miiller material are put into 1 per cent, osmic acid (twenty-four hours 

 at 37 C. for peripheral nerves ; ten to thirty minutes, at room 

 temperature, for central nerve fibres). They are treated with pyro- 

 gallic acid (a photographic developer will do) till the nerve "fibres 

 are black, then with a violet-coloured solution of potassium per- 

 manganate till the sections become brown, then with 2 per cent, 

 oxalic acid till they become yellow-green. Wash out well between 

 each operation. 



Similarly, TELJATNIK (Neurol. CentrU., xvi, 1897, p. 521) ; KoBERf SON 

 (Brit. Med. Journ., 1897 (1), p. 651), the material being previously mor- 

 danted with Weigert's chrome alum- copper fluid for neuroglia ; and 

 OUR, Journ. Path, and Bact., vi, 1900, p. 387. See also ROSSOLIMO and 

 BUSCH, Ztschr. wiss. Mikr.,xiv, 1897, p. 55. 



WITTMAACK (Arch. Ohrenheilk., Ixi, 1904, p. 18) mordants till 

 green (temporal bones) in 90 parts of Miiller's fluid with 10 of 

 formol and 3 to 5 of acetic acid, decalcifies with nitric acid and 

 formol, treats sections (paraffin or celloidin) for a few minutes with 

 2 per cent, osmic acid, and reduces in 5 per cent, pyrogallol. 



873. Iron. ALLERHAND (Neurol. CentrU., xvi, 1897, p. 727) puts 

 sections of Miiller material for fifteen minutes into warm 50 per cent, 

 solution of Liquor ferri sesquichlorati, then for an hour or two into 20 per 

 cent, tannin solution (old and brown). They are then differentiated by 

 PAL'S method, using, however, the liquids twice as strong. 



An iron-alum process is described by STRONG in Journ. Comp. Neurol. , 

 xiii, 1903, p. 291. 



874. Silver Nitrate. VESTARINI-CRESI (Att. Accad. Med. Chir. 

 NapoU, 1, 1896) hardens in formol, cuts thick sections, washes them with 



292 



