It is a dark red product, insoluble in water, quite soluble in methyl alcohol, ethyl alcohol, and acetone, giving purple solutions, but slightly soluble in ether and benzene. Calc. for C~Hs04Fe: Fe, 19.05. Found: 19.8. The cobalt and chromium salts of alizarine as well as the copper and nickel salts of anthrapurpurine and flavopurpurine were prepared and, with the exception of the cobalt salt of alizarine, which analyzed for C~H2101L!o, appear to be normal salts. summary. Copper, cadmium,

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... and iron salts of alizarine axe formed when alizarine is boiled with the respective salts of these metals, anhydrous sodium acetate, and nitrobenzene. These alizarine salts, though slightly soluble in water, penetrate unmordanted wool fiber and produce colors identical with those produced by alizarine in wool fibers mordanted with the respective metallic salts. These dyes appear to be in the fiber and. not simply on the fiber. The formation of an insoluble alizarine dye in a mordanted fiber is accomplished by the combined action of physical and chemical phenomena.