aurum

[Lat. aurum, whence Fr., Gael., & Ir. or; Wel. & Corn. aur; Sp. & Ital. oro; Port. ouro, oiro. The root is aur, ur = to burn, which occurs also in Lat. uro, supine ustum to burn; Gr. ανω ( από ) = to dry, to kindle a fire; Sansc. ush. Mahn suggests O. Pru ian ausas; Lith. auks as; Biscayan urrea = gold.] Chem.: A triatomic metallic element. It may be monatomic in the aurous compounds, which are quickly decomposed into metallic gold and auric salts. Symbol, Au; atomic weight, 197; specific gravity, 19.50; melting point, 1102° C. Gold is a soft yellow metal, ductile and malleable. It di olves in nitro muriatic acid, and it is obtained pure by precipitation from its solution by a ferrous salt. [GOLD.] The following are tests for aurum (gold) in solution. The sulphides are precipitated from acid solutions by H2S, and are soluble in ammonium sulphide. Ferrous sulphate (FeSO4) gives a brown precipitate, fusible by the blowpipe into a bead of metallic gold. Stannous chloride (SnCl2) gives a brownish-purple precipitate (Purple of Ca ius). Oxalic acid slowly reduces gold to the metallic state. Pota ium cyanide gives a yellow precipitate, soluble in exce . A piece of paper dipped in a solution of gold becomes purple on exposure to the light. All salts of gold are reduced to the metallic state by heat. * aurum fulminans. [Lat. ( lit. ) = fulminating gold; gold darting lightning.] An explosive compound made by di olving gold in aqua regia, and precipitating it with salt of tartar. A very small quantity of it becomes capable, by a moderate heat, of giving a report like that of a pistol. ( Quincy .) "Some aurum fulminans the fabrick shook." Garth: Dispensary, iii. 303. IMG:content-0901.png:[blocks in formation] B. Med . The art of discovering diseases within the body by means of the sense of hearing. Being carried out most efficiently by means of an instrument called a stethoscope, it is often called mediate auscultation. It is used to study the natural sounds produced within the body, especially the action of the lungs and heart, both in health and disease. Its operation can be facilitated by percu ion of the surface. [STETHOSCOPE.] "... the application of auscultation to the exploration of the sounds developed in its [the heart's] action." -Todd & Bowman: Physiol. Anat., 1. 29.