NEUROGLIA AND SENSE ORGANS 543 



rinses and places in a neutral solution of ethyl violet and orange G for 

 twelve hours. Blot and then agitate quickly in anhydrous acetone, 

 place in toluol for a few seconds, then flood the slide with pure clove oil 

 and differentiate further in 3 parts of clove oil and 1 part of 95 per cent, 

 alcohol, rinse in pure clove oil, then toluol, xylol (six changes) balsam. 

 (The neutral ethyl violet-orange G solution is most easily prepared by 

 adding to 100 c.c. of distilled water 0-5 grm. of orange G and 1 grm. 

 ethyl violet. Stir thoroughly and place in the oven to precipitate for 

 twelve to twenty-four hours. Decant the supernatant liquid and wash 

 the precipitate several times with distilled water. Place in the oven to 

 dry. INIake a saturated alcoholic solution of the dried powder as stock 

 and use 1 part of this with 3 parts of 20 per cent, alcohol as staining 

 solution.) 



Bailey also uses this method on material fixed in Regaud's solution 

 to demonstrate certain special granules in the cells of the pars anterior 

 hypophysis. 



Kultschitzky's Rubin Method {Anat. Anz., vii, 1893, p. 357) is no 

 longer used. For the slight modification of this method of Popow, see 

 Zlschr. zoiss. Mikr., xiii, 1896, p. 358, and for that of Burchardt, La 

 Cellule, xii, 1897, p. 364. 



The method of Yamagiwa {Virchow's Arch., clx., 1900, p. 358) is also 

 no longer used. 



1090. Methods for Neuroglia Cell-bodies and Granules. Oppenheim 

 (Neurol. Cenlrbl., xxvii, 1908, p. 643) mordants sections made from 

 frozen formalin material with Weigert's copper acetate-chromium 

 fluoride mixture and then stains them with Weigert's iron haematoxylin 

 prepared without hydrochloric acid. An important point of this method 

 is that the material and the sections should not have been treated with 

 alcohol before staining. 



EiSATH (Monatschr. Psych. Neurol, xx, 1906, p. 3 ; Arch. f. Psych., 

 xlviii, 1911, p. 897) fixes large pieces in a modified Orth's formol-Miiller 

 mixture consisting of water 1000 c.c, potassium bichromate 25 grm., 

 sodium sulphate 15 grm., and formalin 150 c.c. to be added at the 

 moment of using the mixture. After about four weeks the tissues are 

 ready for being cut without imbedding, but can be kept for many 

 months, and even years, in 4 per cent, formalin. The sections are col- 

 lected in 4 per cent, formalin, in which they may be kept until wanted. 

 For the staining the sections are put for thirty seconds in a 0-2 per cent, 

 solution of sublimate, well washed in water, and lifted on to the slide, a 

 dilution of an old Mallory's phosphomolybdic-carbolic acid haematoxylin 

 being poured on them. After a few minutes they are washed with water, 

 differentiated with a mixture of equal parts of 40 per cent, tannic acid, 

 50 per cent, alcohol, and 20 per cent, pyrogallic acid in 80 per cent, 

 alcohol. Wash in alcohol, dehydrate, clear and mount. 



FiEANDT (Arch. mikr. Anal., Ixxvi, 1910 — 11, p. 125) fixes in Heiden- 

 hain's sublimate-trichloracetic mixture, and treats pieces for five to 

 seven days with 96 per cent, alcohol, to be changed three times during 

 the first twenty-four hours and daily in the following days. After 

 dehydration the pieces are imbedded in paraffin as directed by Prantner, 

 clearing with cedar oil and ligroin, and putting thence into a saturated 

 solution of paraffin in ligroin in the incubator at 37° C. ; thence into 

 paraffin of 52° C. melting point. The sections, 3 to 5 /x thick, are stuck 

 to slides, freed from sublimate by the usual iodine treatment, and then 

 stained for twelve to twenty-four hours with Mallory's phosphotungstic 

 haematoxylin. Dry with filter paper, differentiate for a few hours in 

 10 per cent, iron perchloride in absolute alcohol, blot once more with 

 filter paper, wash, dehydrate and mount. 



Neuroglia fibres, cji:oplasm of neuroglia cells, and glia granules 



