5. THE STAINING OF NEUROGLIA.
A. Weigert’s Method.
1. Fix small pieces of fresh tissue in 10 per cent formol for 24 hours.
2. Mordant. 8 days at room temperature (4 days at 37°C.) in copper acetate 5 grms., fluorchrom 2.5 grms., acetic acid 5 cc., water 100 cc.
Or, harden and mordant at the same time in 9 parts of the copper mordant, and 1 part of commercial formol for 8 days, changing on the second day, and once again later.
3. Wash in water: after-harden in alcohol; imbed in celloidin; cut.
4. Place sections in ⅓ per cent aqueous solution of potassium permanganate.
5. Wash in two changes of water.
6. Place in the following reducing mixture, 2-4 hours: Chromogen 5 grms., formic acid (sp. gr. 1.2) 5 cc., water 100 cc.; filter; to 90 cc. add 10 cc. of 10 per cent sodium sulphite solution just before using.
7. Wash twice in water.