Acanthus, Gr. and R. (ἀκὴ a point, and ἄνθος, a flower). A plant, the ornamental foliage of which has been largely employed as an architectural decoration by different peoples. The acanthus has been applied to the ornamentation of friezes, cornices, modillions, and various other members of architecture, but in especial to the decoration of modillions (projecting brackets) (Fig. [4]) and of Corinthian and composite capitals. There are several varieties of the acanthus; those most in use are the cultivated acanthus, or Brankursine (Acanthus mollis), and the spring acanthus (Acanthus spinosa), the foliage of which is much less beautiful, and furnished with small spikes which make the plant resemble a thistle. This last has also often been applied to decoration, in the Romano-Byzantine and lanceolated styles of architecture. An English name for this ornament is the “bear’s claw.”
Fig. 5. Bracket decorated with acanthus.
Acapna, Gr. (α, priv., and καπνὸς, i. e. without smoke). Wood for fuel, which had undergone several operations to hinder it from smoking when put on the fire. One of the methods employed consisted in stripping the bough of the bark, immersing it in water for some days, and then leaving it to dry. In a second method, the surface was rubbed with oil or oil-lees, or else the piece of wood was plunged into the oil for a few moments. A third method consisted in slightly charring the surface of the wood by passing it through the flame. The wood prepared by this last process was also called cocta and coctilia.
Acatium, Gr. and R. (ἀκάτιον, dimin. of ἄκατος, a light boat). A description of vessel belonging to the class called actuariæ, i. e. were propelled either by sails or oars. The acatium was a fast-sailer much employed by the Greek pirates. The stern was of a rounded concave form (inflexa), and the prow was adorned with a beak (rostrum). (See also Actuariæ.) The name acatium was also given to a drinking-vessel which was in the form of a boat. The Roman scapha was a similar vessel.
Acca. A word used in the 14th century for a cloth of gold shot with coloured silk, figured with animals: from Acre in Syria.
Accesi, It. (inflamed). One of the Italian Literary Academies. Their device was a fir-cone placed over a fire, with the motto “hinc odor et fructus.”
Accetta, Med. Lat. A battle-axe, or hache-d’armes.
Accidental or complementary colour, the prismatic complement of a ray of light: such are orange to blue, green to red, and purple to yellow.
Accidental light. An effect of light in a picture independent of the principal light, such as that on the Holy Child in the Notte of Correggio, or that of a candle, &c.