The iodine reaction is also applied to fresh tissues by pouring Lugol’s solution over a freshly cut surface, and is a good gross test for amyloid. In both microscopic and macroscopic preparations iodine gives a mahogany brown color to amyloid; other tissue is yellow. The iodine reaction may be intensified by placing the sections in a 1 per cent sulphuric acid; the brown color may be changed to blue, violet or green. 2. =Methyl Violet.= 1. Stain in 0.5 per cent methyl-violet solution ½ to several minutes. Examine in water. 2. Wash in water. 3. Differentiate in 2 per cent acetic or dilute hydrochloric acid 1-2 minutes. 4. Wash thoroughly in water. 5. Mount in lævulose or glycerin-gelatin. Amyloid ruby red; tissue blue-violet. 3. =Gentian Violet.= Use same method as for methyl violet. The same color-effects are produced. 4. =Methyl Green.= Use methyl green in the same way as methyl violet. Amyloid sky-blue or violet; tissue is green. 5. =Iodine Green.= 1. Stain for 24 hours in a ⅓ per cent water solution of iodine green. 2. Wash in water. 3. Mount in lævulose, glycerin or glycerin-gelatin. Amyloid red violet; tissue green. 6. =Birch-Hirschfeld’s Method.= 1. Stain in a 2 per cent alcoholic solution of Bismarck brown for 5 minutes. 2. Wash in absolute alcohol. 3. Wash in water. 4. Stain in a 2 per cent water solution of methyl-violet (or a 20 per cent gentian violet) for 5 minutes. 5. Differentiate in 1 per cent acetic acid until the non-amyloid parts are brown. 6. Wash thoroughly in water. 7. Mount in lævulose, glycerin or glycerin-gelatin. Nuclei are brown; amyloid ruby red. 7. =Green’s Method.= To a few cc. of hæmalum in a watch-glass add a saturated solution of methyl-violet, drop by drop, until the mixture shows a faint purple-red tinge at the edge of the glass. 1. Stain sections 15-30 minutes. 2. Differentiate in acid alcohol until the purple begins to fade. 3. Wash thoroughly in water. 4. Mount in glycerin. (Sections may be blotted and dehydrated in pure liquid paraffin; the latter is then removed by blotting with xylol, and then mount in pure white vaseline.) Nuclei are blue, amyloid ruby-red. 8. =Kresyl-echt-violett (Morse’s Method).= Kresyl-echt-violett (R. extra) 1 grm., 5 per cent carbolic acid 80 cc., alcohol 20 cc. Mix, stirring well; filter. Solution keeps well, and can be diluted as desired without precipitating. 1. Stain 1-5 minutes. 2. Wash thoroughly in distilled water, differentiating, if necessary. 3. Blot with filter paper. 4. Dehydrate in absolute alcohol as quickly as possible. 5. Clear in turpentine. Blot nearly dry before mounting. 6. Mount in balsam.