And speaking of green

Here, fortuitously, is another piece courtesy of reproductionfabrics.com:

Poison Greens

The color green has always been a challenge for dyers and printers. Chlorophyll, the compound that makes plants green, is unstable as a dye for wool, silk or cotton.

Early fabric dyers used a two-step method of dying green-- first with yellow (quercitron, weld, Persian berry, or chrome yellow) and then over dying with indigo or Prussian blue. Warwick green was used to achieve green detailing (stems and leaves) by painting on an indigo ‘pencil blue’ mixture containing aluminated potash (a mordant for quercitron). A quick dip in a quercitron dye bath produced the desired green with good registration.

Arsenic greens were first discovered in 1778 by Swedish chemist Karl Scheele. The colorant was very popular for interior decor, especially wallpapers. Cases of poisoning caused by arsenic in green wallpaper were documented throughout the 19th century. The cause of the illness was frequently misdiagnosed because the symptoms were so general and came on gradually. It is still unclear how the poison was absorbed. One theory is that arsenic may have been transferred into the air of damp rooms by fungi living on the wallpaper paste converting inorganic arsenic into a gas.

Emerald green dye, also known as acid green, solid green and Victoria green, was first produced in an attempt to improve on Scheele’s green. The new dye was used on mordanted cottons to produce a dramatic green (see #RR514G). Another version, Paris green, was used as a pigment for wallpaper, artificial flowers and most affectedly as an insecticide. For a brief period, emerald green was used to dye silks. This exquisite new color was immediately popular for ball gowns.

Eventually, "The Lancet", a British medical journal, spearheaded a campaign to banish arsenic greens because of the many illness and deaths attributed to the dye. By 1875, several British manufacturers had switched to arsenic free greens in wallpapers and paints. In was not until the early 1900s, that there were limits to the amounts of arsenic allowed in wallpapers in the United States. Could this emerald green color with its brief and tragic history be the origins of the term ‘poison green’?