A REVIEW OF THE GOLGI METHOD. 167 



by photographers to stahi and fix their pictures upon aristotype 

 paper is to be preferred to all other substances given here (natu- 

 rally for the special purpose of the treatment of the sublimate 

 preparations). 



" From the many formulse of this kind which are found in 

 books on photographic technique, I have adopted one which I 

 repeat in a footnote.''' 



" The modification which 1 have adopted with my sublimate 

 method is as follows : 



" The pieces which have been proven to be successfully im- 

 pregnated are embedded in celloidin in the usual way and cut with 

 the microtome. The sections are then subjected to the following 

 treatment : 



"(i) Washing in distilled water. 



" (2) Immersion one or two minutes (they can also remain 

 several minutes without injury) in the above fixing and staining 

 fluid. Several cubic centimetres of the fluid suffice for many 

 sections. The blackening can be observed with the naked eye. 



" (3) Careful washing in distilled water. 



" (4) If desired, light carmine stain to bring out the cell bodies 

 and nuclei in the fine interstitial nervous network. Acid carmine 

 is best adapted for this, according to my experience, and I find 

 especially suitable a dilution of this staining fluid with acetic acid 

 and alcohol (equal parts). The fluid into which the sections are 

 brought must have a deep red colour. 



" (5) Repeated washing in water, and then successive trans- 

 ference into alcohol and clove oil, and finally mounting in Canada 

 balsam or damar in the usual way. 



" Preparations treated in this way possess, besides the above- 

 mentioned advantages, the additional one that the fine powdery 



* For toning the two following solutions are separately prepared : 



(a) Water, i litre ; Sodium hyposulphite, 175 g. ; Alum, 20 g. ; Ammo- 

 nium sulphocyanide, log. ; Sodium chloride, 40 g. This mixture stands quiet 

 for 8 days, and is then filtered. 



{b) Water, 100 g. ; Gold chloride, i g. 



To prepare the bath one mixes of solution {a), 60 com. ; of solution {b), 

 7 ccm. ; old, combined bath, 40 ccm. For economy and convenience I use 

 fluid which has also served for toning, thus for this purpose almost useless. 



