MYELIN STAINS. 409 



Sections are made, well washed in water, and brought 

 into a stain composed of — 



Hsematoxylin . . . 0'75 to 1 part. 



Alcohol . . . . .10 parts. 



Water ... . 90 „ 



Saturated solution of lithium carbonate 1 part. 

 They remain there for spinal cord, two hours ; medullary 

 layers of brain, two hours ; cortical layers, twenty-four 

 hours. 



They are then again well washed with water, and brought 

 into a decolorising solution composed of — 



Borax ... 2-0 parts 



Ferricyanide of potassium 25 „ 



Water 200-0 „ 



They remain there until complete diffei'entiation of the 

 nerves (half an hour to several hours), and are then u-ell 

 waished with water (running, or changed several times), 

 dehydrated, and mounted in balsam. They may be 

 previously stained, if desired, with alum-carmine for the 

 demonstration of nuclei. 



The method is applicable to the study of jieripheral nerves 

 as well as to nerve-centres, and also to the study of lymphatic 

 glands, skin (see Schieffeedecker, Anat. Anz., ii, 1887, p. 

 680), bile capillaries, and other objects. 



The process is applicable to tissues that have been hai'dened in alcohol 

 or in any other way, provided that they be pnt into a sokition of a 

 chi-omic salt until they become brown, before mordanting them in the 

 copper solution. 



It is not necessary that the mordanting be done in bulk. 

 Max Fldsch {^Zeit. wi.is. Mih., iii, 1886, p. 50) prefers 

 (following Lichtheim) to make the sections first, and mordant 

 them separately. 



Vassale (quoted from Baton's Hist. Unterauclmngsmeth. 

 d. Nervensy stems, Wiirzburg, 1905, p. 124) first stains the 

 sections in 1 per cent, hsematoxylin, for three to five minutes, 

 then puts for three to five minutes into saturated solution of 

 acetate of copper, and differentiates. 



78?. Weigekt's 1891 Method [Deutsche med. Wodienschr., 

 42, 1891, p. 1184; Ztit. wiss. Mih., viii, 1891, p. 392).— The 



