Literary Notices. xxxiii 



tion is good, though not so perfect as the osmic acid fixation to be mentioned 

 beyond. The differentiation is good centrally, but not so brilliant peripherally 

 as desired. 



25 F. The same fixation, mordant and stain, but decolorized in Kult- 

 schitzky's fluid. About the same result as in the last case. 



26 F. The same fixing fluid as in No. 24, applied 14 days, mordanted in 

 4 per cent, iron alum, one-half hour, stained in y^ per cent, aqueous hematoxylin, 

 one-half hour, and decolorized in 4 per cent, iron alum. The fixation is very 

 good periphally. In the brain we get some shrinkage and fragmentation of 

 sheaths. The nerves stain well and the peripheral tissues decolorize perfectly. 

 This is primarily an axis cylinder stain, though the sheaths can be differentiated 

 also, if not decolorized too far. 



27 F. The same fixation as the last. The sections mordanted in warm 

 Erlicki's fluid for one hour ; stained in warm acid hrematoxylin one hour ; de- 

 colorized in Kultschitzky's fluid. This gives a good Weigert preparation with a 

 clear ground peripherally except near the edges. 



28 F. Same fixation as the last. Sections mordanted one and one-half 

 hours in warm half-saturated copper acetate, stained three hours in Weigert's 

 haematoxylin and decolorized in Kultschitzky's fluid. The preparations are 

 about like those in No. 27. 



29 F. Fixation as before. Sections mordanted Wolter's vanadium chlo- 

 ride and aluminium acetate, four hours, stained in acid hasmatoxylin 3 hours, 

 and decolorized in Weigert's decolorizer. This gives good differentiation cen- 

 trally, but peripherally the muscles do not decolorize so well as in the last cases. 



30 F. Fixation as before. Sections mordanted in Weigert's new mordant 

 (saturated copper acetate and 10 percent, sodium potassium tartrate equal parts) 

 for three hours warm, followed by half-saturated copper acetate for two hours ; 

 stained in Weigert's ha^matoxylin for two hours ; decolorized in Weigert's de- 

 colorizer. These are the most satisfactory sections thus far mentioned. The 

 characteristic Weigert reaction is very brilliant both centrally and periphally 

 and the muscles and other peripheral tissues clear well. 



Sumt7iary. — Chrom-acetic alone cannot be applied long enough to 

 effect any considerable decalcification without injury to the tissues, 

 especially to the medullary sheaths. The addition of formalin (20 per 

 cent, of the whole mixture) in large measure corrects this defect, 

 though acids should be used rather strong, the proportions used in 

 Flemming's stronger formula giving good results. This fixation per- 

 mits excellent Weigert's preparations and promises well. I found, 

 however, that still better results can be secured by the use of Flem-' 

 ming's fluid as described below ; hence this line of experimentation 

 was discontinued. 



VI — FIXATION IN OSMIC ACID MIXTURES. 



Combinations of osmic acid with nitric acid and picric acid have al- 

 ready been mentioned. The osmic acid mixtures which I have found 

 most useful are (A) Hermann's fluid, and (B) Flemming's fluid. 



