62 W. H. E M I G 



of large size are stained within 15 minutes. All of these materials 

 are dehydrated from 10 per cent glycerin. 



1006. Sulfur Green, Sulfogene Green 2B (Du Pont), Sulfo- 

 gene Brilliant Green 2G (Du Pont), and Sulfur Green 3G cone. 

 (NAC) are direct dyes, light 2; 1/10 gram in 100 ml. of 1 per cent 

 sodium sulfide and 1 ml. of 4 per cent sodium hydroxide. The 3G 

 shade gives a bright green; the 2B, a blue-green at 50° C. on blue- 

 green algae in three to ten hours, on invertebrates in 30 minutes. 



1012. Sulfur Bordeaux, Sulfogene Bordeaux BRN (Du 

 Pont), and Sulfur Bordeaux BCF (NAC) are direct dyes, light 2; 

 1/10 gram in 95 ml. of 1 per cent sodium sulfide and 5 ml. of 4 per 

 cent sodium hydroxide. At 50° C., plant tissues are stained in 12 

 to 24 hours, invertebrates in 30 minutes. The oxidation treatment 

 is unnecessary for Sulfur Bordeaux. 



Class XXII. Hydroxy ketone Colouring Matters 

 These dyes are used in the color printing of wool. 



Class XXIII. Anthraquinone Colouring Matters 



1027. Alizarin is an acid mordant dye, light 4 to 3; ^ gram in 

 100 ml. of distilled water and 1 ml. of 4 per cent sodium hydroxide. 

 The dye is insoluble in water, slightly soluble in alcohol, and blue- 

 violet in dilute alkalies. Upon the addition of an acid to the alka- 

 line stain, a yellow precipitate is formed. The dye produces a wide 

 range of colors depending on the metallic salt used as a mordant, the 

 alkalinity of the stain, and the temperature of application. A few 

 of the mordants with the accompanying color lakes are : aluminum, 

 orange to red ; copper, carmine ; antimony, brown ; chromium, bor- 

 deaux ; uranium, blue-violet ; and iron, blue-black to black. All of 

 the lakes are darker when developed at 50-60° C. 



The stain is easily applied to invertebrates of any size. The 

 technique includes a mordant for 30 minutes ; after a rinse in dis- 

 tilled water, Alizarin is applied at 40-50° C. for five minutes. The 

 best colors develop after : ammonium alum, orange-red to red ; cop- 

 per acetate, carmine ; or ferric alum, dark red at room temperature 

 to blue-black at 50° C. Paraffin sections of earthworm are dull red 



