Search the Dictionary

t of the former to three of the latter, and remarkable for its solvent action on gold and platinum; -- called also nitromuriatic acid, and aqua regia.

To take in and retain; to absorb; -- said especially with respect to gases; as iron, platinum, and palladium occlude large volumes of hydrogen.

Occlusion of gases (Chem. & Physics), the phenomenon of absorbing gases, as exhibited by platinum, palladium, iron, or charcoal; thus, palladium absorbs, or occludes, nearly a thousand times its own volume of hydrogen, and in this case a chemical compound seems to be formed.

A rare metallic element of the platinum group, found native as an alloy in platinum ore, and in iridosmine. It is a hard, infusible, bluish or grayish white metal, and the heaviest substance known. Its tetroxide is used in histological experiments to stain tissues. Symbol Os. Atomic weight 191.1. Specific gravity 22.47…

A rare metallic element of the light platinum group, found native, and also alloyed with platinum and gold. It is a silver-white metal resembling platinum, and like it permanent and untarnished in the air, but is more easily fusible. It is unique in its power of occluding hydrogen, which it does to the extent of nearly…

al set of teeth which fits to the mouth, and holds the teeth in place. It may be of gold, platinum, silver, rubber, celluloid, etc.

Looking backward; contemplating things past; -- opposed to prospective; as, a retrospective view. The sage, with retrospective eye. Pope.

A rare element of the light platinum group. It is found in platinum ores, and obtained free as a white inert metal which it is very difficult to fuse. Symbol Rh. Atomic weight 104.1. Specific gravity 12.

an unwrought or rude condition; unpolished; as, a diamond or a sketch in the rough. Contemplating the people in the rough. Mrs. Browning.

A rare element of the light platinum group, found associated with platinum ores, and isolated as a hard, brittle steel-gray metal which is very infusible. Symbol Ru. Atomic weight 103.5. Specific gravity 12.26. See Platinum metals, under Platinum.

itizes. The sensitizer should be poured on the middle of the sheet. Wilis & Clements (The Platinotype).

An arsenide of platinum occuring in grains and minute isometric crystals of tin-white color. It is found near Sudbury, Ontario Canada, and is the only known compound of platinum occuring in nature.

West Indies. -- Horse sponge, a coarse commercial sponge, especially Spongia equina. -- Platinum sponge. (Chem.) See under Platinum. -- Pyrotechnical sponge, a substance made of mushrooms or fungi, which are boiled in water, dried, and beaten, then put in a strong lye prepared with saltpeter, and again dried in an o…

ing fluids, like a sponge. Spongy lead (Chem.), sponge lead. See under Sponge. -- Spongy platinum. See under Platinum.

by the application of heat. Paquelin's thermocautery, thermocautery by means of a hollow platinum point, which is kept constantly hot by the passage through it of benzine vapor.

- Vacuum pump. Same as Pulsometer, 1. -- Vacuum tube (Phys.), a glass tube provided with platinum electrodes and exhausted, for the passage of the electrical discharge; a Geissler tube. -- Vacuum valve, a safety valve opening inward to admit air to a vessel in which the pressure is less than that of the atmosphere, i…

), a fanciful name of an apparatus designed to oxidize alcohol to acetic acid by means of platinum. -- Vinegar plant. See 4th Mother. -- Vinegar tree (Bot.), the stag-horn sumac (Rhus typhina), whose acid berries have been used to intensify the sourness of vinegar. -- Wood vinegar. See under Wood.