=Glycerin=, =potassium acetate=, =laevulose= and =glycerin-gelatin= are used for the preservation of amyloid-, mucin- and fat-stains, as well as for other preparations that do not permit the use of alcohol and xylol. =Glycerin-gelatin= is probably the best medium for this purpose. It is made according to _Kaiser_ by soaking 7 grms. of gelatin for 2 hours in 42 cc. distilled water, then adding 50 grms. glycerin and 1 grm. carbolic acid; the mixture is warmed 10-15 minutes, stirring constantly, and filtered while hot. It is also made by taking water, 200 cc.; gelatin, 20 grms.; powdered white shellac, 2 grms.; Farrant’s solution (gum arabic, glycerin, solutio acidi arsenicosi conc., _aa._ 30.0 grms.), dissolve by warming, and filter while warm. To mount in this medium the section is placed on the slide, and blotted with absorbent paper. A drop of warm glycerin-gelatin is then placed on it and the cover-slip affixed. The drop spreads evenly beneath the cover-glass and becomes solid as it cools. Mounts in glycerin, glycerin-gelatin, potassium acetate and laevulose must be cemented around the borders of the cover-slip with asphalt, wax, paraffin, gold size, etc., using a brush or glass rod for this purpose. VII. SUMMARY OF METHODS OF PREPARATION OF CELLOIDIN SECTIONS. 1. Fixation of the tissues in alcohol, formol, etc. 2. Wash 24 hours, when necessary. 3. After-harden in 80 and 95 per cent alcohols for 1 to several days. 4. Complete dehydration in absolute alcohol for 24 hours. 5. Equal parts of pure ether and absolute alcohol, 24 hours. 6. Thin celloidin, 1-3 days. 7. Thick celloidin, 1-3 days. 8. Block. Harden block in 80 per cent alcohol. 9. Cut; keep sections in 80 per cent alcohol. 10. Stain; differentiate. 11. Wash thoroughly. 12. Dehydrate in 80 and 95 per cent alcohols. 13. Final dehydration and clearing in carbol-xylol. 14. Place on slide and blot with absorbent paper. 15. Mount in xylol-balsam or xylol-colophonium. VIII. SUMMARY OF METHODS OF PREPARATION OF PARAFFIN SECTIONS. 1. Fixation of the tissue in alcohol, formol, etc. 2. Wash 24 hours, when necessary. 3. After-harden in 80 and 95 per cent alcohol for 1 to several days. 4. Complete the dehydration in absolute alcohol for 24 hours. 5. Aniline-oil until tissue becomes transparent. 6. 1st. Xylol, ½ hour, to remove aniline oil. 7. 2nd. Xylol, 1-2 hours, until translucent. 8. 1st. Paraffin (52°C.), ½ hour in oven, to remove xylol. 9. 2nd. Paraffin (52°C.), 1-12 hours in oven, until infiltrated. 10. Imbed and block; cool quickly. 11. Cut sections; mount on slides or covers. 12. Remove paraffin in xylol. 13. Remove xylol in absolute alcohol. 14. 80 per cent alcohol, for a few minutes. 15. Stain; differentiate; wash. 16. Dehydrate in 80 and 95 per cent alcohols. 17. Clear in carbol-xylol. 18. Mount in Canada-balsam or colophonium.