474 APPENDIX. 



reference to 696, this modification of Weigert's process is essentially 

 identical with that of LISSAUEE. 



Another process given by KAISEE, loc. cit., is as follows : Sections to be 

 mordanted for a few minutes in a mixture of 1 part liquor ferri sesqui- 

 chlorati, 1 part distilled water, and 3 parts rectified spirit, then stained 

 in Weigert's stain changed several times until a heavy precipitate is 

 formed, then washed in water and differentiated as before. They are then 

 to be rinsed in ammoniated water and stained in a O'l per cent, solution of 

 fuchsin in rectified spirit, or in a solution of 1 part of naphthylamin brown 

 in 100 of spirit and 200 of water. The fuchsin will stain in about half a 

 minute, the naphthylamin brown in from three to five minutes. Mount as 

 usual. Medullated nerves blue, non-medullated red or brown. The re- 

 action will be enhanced if the sections be warmed in the stain. 



877. Preservation of Golgi's Bichromate of Silver Preparations. 



KALLIUS (Anat. Hefte, ii, 1892, p. 269; Zeit. f. wiss. Mik., 

 ix, 4, 1893, p. 477) lias worked out the following process. 

 Take 20 c.c. commercial hydroquinone developing solution 

 and 230 c.c. distilled water (the hydroquinone solution may be 

 made up with 5 grins, hydroquinone, 40 grms. sodium sul- 

 phite, 75 grms. carbonate of potassium, and 250 grms. dis- 

 tilled water). At the instant of using, further dilute the 

 solution with one third to one half its volume of absolute 

 alcohol, and put the sections into it for several minutes ; they 

 become dark grey to black. In order to ascertain whether 

 reduction is complete, throw a section into a solution of 

 hyposulphite of soda (about 10 parts to 50 of water) : 

 chromate of silver will quickly dissolve, whilst metallic silver 

 will not be attacked. As soon as reduction is complete the 

 sections are put for ten to fifteen minutes into 70 per cent, 

 alcohol, then brought for five minutes into the above-given 

 solution of hyposulphite of soda, and thence into a large 

 quantity of distilled water, where they should remain for 

 twenty-four hours or more. Lastly, dehydrate in the usual 

 way, and mount under a cover. All the details which in the 

 undeveloped preparations were brown are now black on a 

 light ground. After-staining with carmine, &c., may be em- 

 ployed. Other developers were tried, and gave satisfactory 

 reductions, but they caused a red or brownish discoloration 

 of the preparations. 



To the references to the paper of HUBEE given in 712, 

 add that to Zeit. f. wiss. Mik., ix, 4, 1893, p. 479. The 

 reader will of course understand that the balsam is to be 



