Sodium gives an intense and persistent yellow flame; lithium gives a carmine coloration, and may be identified in the presence of sodium by viewing through a cobalt glass or indigo prism; from potassium it may be distinguished by its redder colour; barium gives a yellowishgreen flame, which appears bluish-green when viewed through green glass; strontium gives a crimson flame which appears purple or rose when viewed through blue glass; calcium gives an orange-red colour which appears finch-green through green glass; indium gives a characteristic bluish-violet flame; copper gives an intense emerald-green coloration.
P. Alkekengi from South Europe has long been known in gardens for its bright orange-red globular calyxes.
It is probable that the Liberian chimpanzee may offer one or more distinct varieties; there is an interesting local development of the Diana monkey, sometimes called the bay-thighed monkey (Cercopithecus diana ignita) on account of its brilliant orange-red thighs.
The haematoidin pigment may vary in colour from yellowish or orange-red to a ruby-red, and forms granular masses, rhombic prisms or acicular crystals.
It forms with silver nitrate the yellowish green solid, Ag 2 S AgNO 3, and with silver sulphate the orange-red powder, Ag 2 S Ag 2 SO 4 Silver sulphate, Ag 2 SO 4, is obtained as white crystals, sparingly soluble in water, by dissolving the metal in strong sulphuric acid, sulphur dioxide being evolved, or by adding strong sulphuric acid to a solution of the nitrate.
The solution is of an orange-red colour, and is quite permanent in the dark, but on exposure to light, gradually becomes colourless, owing to decomposition into hydrobromic acid and oxygen.
They are about the size of a pigeon, with orange-coloured plumage, a pronounced crest, and orange-red flesh, and build their nests on rock.
Gloriosa, well known in cultivation, climbs by means of its tendril-like leaftips; it has handsome flowers with decurved orange-red or yellow petals; it is a native of tropical Asia and Africa.
Detection and Estimation.-Most calcium compounds, especially when moistened with hydrochloric acid, impart an orange-red colour to a Bunsen flame, which when viewed through green glass appears to be finch-green; this distinguishes it in the presence of strontium, whose crimson coloration is apt to mask the orange-red calcium flame (when viewed through green glass the strontium flame appears to be a very faint yellow).
Good saffron has a deep orange-red colour; if it is light yellow or blackish, it is bad or too old.