IL'2 APPENDIX TO THE HISTOLOGICAL SECTION. 



violet and the latter a black colour. If treated with the iron alum 

 they remain in it for 24 hours at the ordinary temperature, whilst in 

 the case of the osmic acid they remain until of a fawn colour. 



4. Staining. After mordanting wash in water and stain in 

 Kultschitzki's hsematoxylin (hsematoxylin Is dissolved in a little 

 alcohol added to 100 cc of a 2i xc - solution of acetic acid). 



5. Oxydizing. Wash in water, place in '25 P- C - solution of potassium 

 permanganate for five minutes. 



6. Decolourising. Wash in water and place in Pal's decolouriser 

 (oxalic acid is, solution of sodium sulphate Is, distilled water 200 cc ). 

 In this they remain until the grey matter is decolourised. If this does 

 not occur in five minutes repeat the processes 5 and 6. Finally rinse 

 in water and pass through absolute alcohol, through toluene, or 

 chloroform to xylol (Bolton), and mount in balsam. The great 

 advantage is that No. 4 solution keeps a considerable time as compared 

 with Weigert's formula. 



24. Eosin. A strongly tinted or saturated solution in water or 

 alcohol is employed according to the purpose for which it is required. 

 Strong aqueous solution for staining blood films or sections on the slide. 

 The alcoholic solution is used for imparting a ground stain in bulk when 

 dehydrating before clearing for paraffin embedding. 



25. Spillep's purple or fuchsine are used in strong aqueous 

 solutions. These stain elastic fibres selectively. 



26. Methylene blue (S. Meyer's). 0*5 P- C - to saturated solution 

 in normal saline for staining nerve terminations in tissues. In time it 

 also colours nuclei and the cement substance between epithelial cells. 

 Free access of oxygen is required during the process, as colourless 

 leuco-products are otherwise formed in the tissues. The stain is 

 evanescent and must be fixed when at its best stage. A saturated 

 solution of ammonium picrate in water is employed to fix the colour 

 when it has developed to the required extent. Subsequent preserva- 

 tion is accomplished in glycerin, to which an equal volume of 

 ammonium picrate has been added. This is Dogiel's method. 



Bethe recommends Ehrlich's subcutaneous injections of successive 

 doses of methylene blue in strong solution. Successful results can be 

 obtained by staining very small pieces of the fresh tissue in a saturated 

 solution, examining small fragments from time to time under the 

 microscope to ascertain the result, and then fix first by 15 minutes' 

 treatment in ammonium picrate saturated solution in water, and then, 

 after Bethe, transfer to a mixture containing ammonium molybdate 1 



