Io6 JOUUNAL OK Co.MPARATn'E NeI'ROLOGV. 



the methyl compound is reduced to leucomethyl blue, which 

 is coloi'less. Nevertheless as soon as these tissues are ex- 

 posed to air in thin layers, the oxidation is repeated and the 

 color reappears. 



Feist considers it improbable that oxidation alone is suffi- 

 cient to explain the change, and cites many careful experi- 

 ments to prove that the phenomena are connected with 

 decomposition. 



For sections, fixation of the stained tissue with platinic 

 chloride proved useful, though the color became granular 

 after such treatment. For nerves, treatment with Hoyer's 

 picrocarmine for fifteen minutes, and then with osmic acid 

 for a similar time, was sufficient to prepare them for imbed- 

 ding in gum arable and glycerine. Three or four days may 

 be necessary before the mass becomes of a suitable consis- 

 tency to cut when enclosed in pith. This method has many 

 difficulties growing out of the brief period during which the 

 preparation is in condition to section. The color, if fixed by 

 osmic acid, is not permanent. 



For the interesting results of the application of this 

 method, as well as a comprehensive review^ of the literature 

 of nerve histology, the original paper should be consulted. 

 The following papers will also be found useful; 



O. Schultz. Die vitale Methylenblu reaction der Zell- 

 granula. Anatom. Anzeiger, 1887, No. 22. 



P. Ehrlich. Ueber die Methylenblaureaction der le- 

 bender Nervensubstanz. Deutsch Med. Wochenschrift. 

 18S6, No. 4. 



C Ai-nstein. Die Methylblaufaerbung als histolog- 

 ische Methode, Anat. Anz. 1887, No. 17. 



H. Kuchn. Notiz u. vitale Reaction der Zellgranula 

 nuch subcutaner Methylblauinjection. Arch. f. Anat. u. 

 Phys. 1890. 



