The diacetyl and dibenzylidene compounds were also prepared from these diamino derivatives. The former crystallizes in cubes from dilute alcohol; m. p., 307°C (Corr.) and the latter in beautiful yellow plates from carbon disulphide, m. p., 195°-196°C. (Corr.). An analysis of these two compounds showed the following results, Calc. for Calc. for Found C₁₇H₁₅N₃O₂Se C₂₇H₁₉N₃Se I II Nitrogen 9.05% 11.21% 9.21% 11.43% Dyeing with Azo Dyes Both the monoamino and the diamino derivatives form intensely colored dyes when diazotized and coupled with phenols and aromatic amines. The dyes formed are fast to light. In the following table silk is given to represent the fabrics used. Wool and cotton were dyed similar shades, though with slight variation. Each silk sample was dyed in acid or alkaline baths as indicated and each bath contained 0.01 gram in twenty cc. solution: Diazo. On Diazo. On Coupler monoamine silk diamine silk Phenol deep red v. light (alk) yellow (alk) yellow deep red Dimethylaniline orange light orange-red yellow (acid) yellow (acid) P-nitraniline light brownish grayish brown (acid) brown (acid) P-toluidine light brownish brownish brown (acid) (acid) Pyrogallic dark grayish dark grayish acid brown brown (acid) (alk) Salicylic reddish light red brown acid (alk) brown (alk) B-naphthol deep red pink deep red red (alk) (alk) Sulphanilic light brownish brown brown acid brown (alk) (alk) A-naphthylamine light brownish yellow yellow brown (acid) (acid) Resorcinol purple red dark deep red (alk) purple (alk) BIBLIOGRAPHY 1. Berzelius, Annales de Physique et Chimie (2) 9, 239, 356 (1818). 2. Gmelin-Kraut, “Handbuch der Anorg. Chemie” I (1) 705-804; Roscoe and Schorlemmer, “Treatise on Chemistry” I, 467-82 (1920); Browning, “Introduction to the Rarer Elements,” 144-52 (1917). 3. Victor Lenher, J. Ind. Eng. Chem., 12, 597 (1920). 4. Le Seleneum et ses applications actuelles, Chimie et Industrie (1919) 245. 5. C. R. Boggs, U. S. A., 1,249,272; J. Ind. Eng. Chem. 10, 117-8 (1918).