But after proper treatmenti the former develops a glossy black patina with violet sheen, and the latter shows beautiful shades of grey with silvery lustre.
The Istrian stone of which the edifice is built has taken a fine patina, which makes the whole look like some richly embossed casket in oxidized silver.
It was mainly for the sake of their patina that value attached to the remarkable alloys shakudo (3 parts of gold to 97 of a Ba.
Great importance has always been attached by Japanese experts to the patina of metal used for artistic chiselling.
- Monocyclica in which the dorsal cup is confined to the patina and occasional intercalated anals;: such ambulacrals or interambulacrals as enter the tegmen remain supra-tegminal and not rigidly united.
- Dicyclica in which the dorsal cup primitively is confined to the patina and occasional intercalated anals, and no other plates ever occur between RR (Grade: Distincta); Br may be incorporated in the cup, with or -without iBr, but never rigidly, and their corresponding ambulacrals remain supra-tegminal (Grade: Articulata); new columnals are introduced at the extreme proximal end of the stem.
Even greater value has always been set upon the patina of iron, and many secret recipes were preserved in artist families for producing the fine, satin-like texture so much admired by all connoisseurs.
Copper, tin, lead and zinc, mixed in various proportions by different experts, are the ingredients, and the beautiful golden hues and glossy texture of the surface are obtained by patina-producing processes, in which branch of metal-work the Japanese show altogether unique skill.
Okazaki Sessei has successfully achieved the casting of huge panels carrying designs in high relief; and whether there is question of patina or of workmanship, Jomi Eisuke has never been surpassed.
They may be said to possess a series of bronzes, in which gold and silver replace tin and zinc, all these alloys being characterized by patina having a wonderful range of tint.
The common alloy, Shi-ya-ku-Do, contains 70% of copper and 30% of gold; when exposed to air it becomes coated with a fine black patina, and is much used in Japan for sword ornaments.
In 1905 an art pottery was established for making "crystal patina" and "robin's egg blue" wares, in imitation, to a certain extent, of old oriental pottery, and Clifton India ware, in imitation of pottery made by the American Indians.
- Monocyclica with dorsal cup primitively confined to the patina and an occasional single anal; tegmen solid; portions of the proximal brachials and their ambulacrals tend to be rigidly incorporated in the theca.
A, Notholca longispina, lorica only; b, Anuraea aculeata, like the former, a floating pelagic type (plankton proper); c, Synchaeta stylata; corona with accessory antennae and sensory styles; auricles for swimming - an actively swimming pelagic type (nekton); d, Pterodina patina, with bdelloid corona and retractile foot with terminal ciliated cup; e, Distyla gissensis partly extended; f, Rattulus tigris.
Copper, too, by patina-producing treatment, is made to show not merely a rich golden sheen with pleasing limpidity, but also red of various hues, from deep coral to light vermilion, several shades of grey, and browns of numerous tones from dead-leaf to chocolate.