VIEW THE MOBILE VERSION of Informational Site Network Informational
  Home - Chromatography - Color Value - Aesthetics - Photography


The red obtained from this substance created a great deal of interest
among printers and dyers on its introduction in 1857, or thereabouts.
For purity and brilliancy of shade it was not excelled by any other
colour, but not being able to stand the effects of air and light, its
employment was limited. We are not aware that murexide has yet been
brought forward as a pigment, and judging from its character as a dye,
it would scarcely enrich the palette. Dyes and pigments have much in
common, and a fugitive dye cannot be expected to furnish a permanent

Murexide is produced by the action of ammonia on alloxan, which is
itself derived from the uric acid of guano by treatment with nitric
acid, and was known nearly forty years back to stain the fingers and
nails red. The first murexide sent into the market was a reddish-purple
powder, dissolving in water with a fine purple tint, leaving a little
residue undissolved. Owing to improvements in manufacture, it is now
capable of being prepared almost chemically pure, and with that green
metallic reflection peculiar to several coal-tar salts and the wings of
certain insects. When sulphuretted hydrogen is passed through a
concentrated solution of murexide, it is immediately decoloured; a fact
which renders it likely that murexide pigments would be as liable to
suffer from an impure atmosphere, as from exposure to light and air.

When an alkaline solution of murexide is precipitated by an acid, a
light shining powder results, called purpuric acid. This dissolves in
alkalies, and combines with metalline bases to form various coloured

Next: Compounds Termed Purpurates Among Them May Be Mentioned A Red

Previous: Manganese Red

Add to Add to Reddit Add to Digg Add to Add to Google Add to Twitter Add to Stumble Upon
Add to Informational Site Network

Viewed 2143