AXIS-OYUNDEB AND DENDRITE STAINS. 431 



put into tlie dark. After fifteen to thirty minutes therein, according to 

 their thickness, the sections are quickly washed in 50 per cent, alcohol, 

 then in water, then treated for five or ten minutes (not more) with 

 10 per cent, solution of hyposulphite of soda. They ai'e lastly washed well 

 with water, and may be then mounted at once in balsam under a cover, 

 or if desired may be previously stained with carmine or hsematoxylin, or 

 Pal's modification of Weigert's process, or the like. 



825. Kallitjs {Anat. Hefte, ii, 1892, p. 271) has worked out the follow- 

 ing process. Take 20 c.c. commercial hydroquinone developing solution 

 and 230 c.c. distilled water (the hydroquinone solution may be made up 

 with 5 grms. hydroquinone, 40 gi-ms. sodium sulphite, 75 grms. carbonate 

 of potassium, and 250 grms. distilled water). At the instant of using, 

 further dilute the solution with one third to one half its volume of 

 absolute alcohol, and put the sections (from which the unreduced silver 

 has been removed as far as possible by washing in many changes of 

 alcohol) into it for several minutes ; they become dark grey to black. 

 They are then put for ten to fifteen minutes into 70 per cent, alcohol, 

 then brought for five minutes into solution of hyposulphite of soda 

 (about 10 parts to 50 of water), and thence into a large quantity of 

 distilled water, where they should remain for twenty-foui- hours or 

 more. Lastly, dehydrate in the usual way and mount under a cover. 

 After-staining with carmine, etc., may be employed. 



CrBEEBi {Anat. Anz., xxxii, 1908, p. 432) after fixing tones for a short 

 time in 0'7 grms. gold chloride, 3 grms. sodium acetate, and 100 c.c. water. 



826. Zimmeemann's Process (Arch. mile. Anat., lii, 1898, p. 554). — 

 Sections ai-e brought from alcohol into a large quantity of a mixture of 

 1 part physiological salt solution and 2 parts 96 per cent, alcohol. 

 They must be kept in motion therein for ten to fifteen minutes, after 

 which they are brought into alcohol of 75 to 96 per cent, in a bright light, 

 until they have become dark (half a day). They may be after-stained 

 with thionin (cells blue). 



Later (Arch. Mik. Anat., Ixxviii, 1911, p. 199) he reduces in 20 c.c. of 

 saturated solution of carbonate of soda with 05 grm. of adurol for 

 several hours, and after-stains with hsemalum or alum cochineal. 



Tlie Suhlimate Method. 



827, GoLQi's Bichromate and Sublimate Method {Archivio per 

 le Scieiize Mediche, 1878, p. 3; Archives Italiennes de Biologie, 

 ~iv, 1883, p. 32; vii, 1886, p. 35). — For hardening, use either 

 a solution of bichromate of potash progressively raised from 

 1 per cent, to 2^ per cent., or Muller's solution. It is best 

 to take small pieces of tissue (not more than 1 to 2 c.c), 

 large quantities of liquid, and change the latter frequently. 

 But the reaction can be obtained with much larger pieces, 



