Literary Notices. xxxv 



and decolorize in iron alum, as in the previous cases). The fixation is very 

 good. The medullated nerve fibers under a low power are not brilliantly differ- 

 entiated, yet the high power shows them excellently preserved and the compon- 

 ents can be followed, though not so easily as in some of the Weigert methods 

 given below. 



41 F. Some sections from the last specimen were stained by the method 

 which Kenyon found so satisfactory for the insect brain (Journal Comp. Neurol- 

 ogy; Vol. VI, No. 3, p. 138, 1896.) The sections were mordanted in a warm 5 

 per cent, solution of copper sulphate for i hour and stained in Mallory's haema- 

 toxylin, 



10 per cent, phosphomolybdic acid, i cc. 



Htematoxylin crystals, i g. 



Chloral hydrate, 6 to 10 g. 



Water, 100 cc. 



This stain was diluted with water in the proportion of I of stain to 5 of 

 water and applied for i^ hours. The sections are considerably overstained and 

 have to be decolorized for several hours in 70 per cent, alcohol. This gives 

 beautiful sections of the central nervous system. The stain is rather diffuse, 

 but cells and fiber tracts are both clearly differentiated. Peripherally, however, 

 the muscles, etc., are so deeply stained that no differentiation of nerves is pos- 

 sible. This stain, though not available for my present purpose, is nevertheless 

 a very useful one for the central nervous system. It would doubtless be im- 

 proved by using the dye more dilute and applying for a much shorter time. 



One section stained with iron hematoxylin like No. 40 was afterward 

 stained as above. The result is not so good as either stain separately. A faint 

 counter of the iron-haematoxylin sections with acid fuchsin or some similar dye, 

 is, however, of assistance in differentiating the nerves peripherally. 



43 F. Vassale's modification of Weigert's process. The specimen was fixed 

 II days in Flemming's fluid, sections stained for 5 minutes in Weigert's hema- 

 toxylin and afterwards mordanted in saturated copper acetate for 3 to 5 minutes, 

 and differentiated with Weigert's decolorizer. The nerves are not differentially 

 stained and the sections are of little value. Other decolorizers were tried also. 

 Pal's was still worse than Weigert's. Kultschitzky's lithium carbonate and fer- 

 ricyanide of potassium gives better results, especially if the time in the stain is 

 reduced to one half minute. The muscles, etc., are of a deep yellow color and 

 the nerves a pale greyish blue. These are really excellent preparations and the 

 components of the nerves can be clearly analyzed. 



This rapid method invites further experimentation. I am inclined to think 

 that with very slight modification it will give sections quite equal to the best of 

 those obtained by the more tedious methods to be described below (e. g. Nos. 

 46, 53. 54) This is a true sheath stain, but, like the other Weigert sections 

 made after hardening in Flemming's fluid to be described next, the stain is very 

 intense at the periphery of the fibers and very faint in the remainder of the 

 medullary sheath, so that under a high power the effect is very different from 

 that of the ordinary Weigert methods. The axis cylinder is a dark yellow, 

 clearly differentiated from the sheath. 



46 F. Flemming's fluid li days, sections mordanted in Erlicki's fluid i 

 hour, treated with Kultschitzky's acid hematoxylin 2 hours and decolorized 



