It is a brownish amorphous solid, which is insoluble in water.
It may be obtained as a dark brown amorphous powder by placing a mixture of io parts of the roughly powdered oxide with 6 parts of metallic sodium in a red-hot crucible, and covering the mixture with a layer of well-dried common salt.
Pure amorphous boron is a chestnut-coloured powder of specific gravity 2.45; it sublimes in the electric arc, is totally unaffected by air at ordinary temperatures, and burns on strong ignition with production of the oxide B 2 0 3 and the nitride BN.
Boron chloride BC1 3 results when amorphous boron is heated in chlorine gas, or more readily, on passing a stream of chlorine over a heated mixture of boron trioxide and charcoal, the volatile product being condensed in a tube surrounded by a freezing mixture.
Boron trioxide B203 is the only known oxide of boron; and may be prepared by heating amorphous boron in oxygen, or better, by strongly igniting boric acid.
Cadmium sulphide, CdS, occurs naturally as greenockite (q.v.), and can be artificially prepared by passing sulphuretted hydrogen through acid solutions of soluble cadmium salts, when it is precipitated as a pale yellow amorphous solid.
The Cambridgeshire coprolites are either amorphous or finger-shaped; the coprolites from the Greensand are of a black or dark-brown colour; while those from the Gault are greenish-white on the surface, brownish-black internally.
Allotropic Modifications.-Sulphur assumes crystalline, amorphous and (possibly) colloidal forms. Historically the most important are the rhombic (Sa) and monoclinic (So) forms, discussed by E.
Amorphous sulphur or Sy exists in two forms, one soluble in carbon bisulphide, the other insoluble.
The solid derived from SA is crystalline and soluble in carbon bisulphide, that from S, is amorphous and insoluble.
Well-worn pebbles of amorphous quartz (agate, chalcedony, jasper, &c.) are found in the stratified drift along the western side of the Tertiary region of the state, and from Columbus northward.
The value of d can be evaluated by considering the combustion of amorphous carbon to carbon monoxide and carbon dioxide.
(C 6 H 4 CO 2 H) 2 is obtained by continued heating of salicylic acid and acetyl chloride to 130140° C. It is an amorphous yellow mass which is easily soluble in alcohol.
Gelatin forms a white amorphous powder; the commercial product, however, generally forms glassy plates.
Lead sesquioxide, Pb203, is obtained as a reddish-yellow amorphous powder by carefully adding sodium hypochlorite to a cold potash solution of lead oxide, or by adding very dilute ammonia to a solution of red lead in acetic acid.
The oxychloride comes down as an amorphous white precipitate.
White lead is an earthy, amorphous powder.
It is a reddish amorphous mass, insoluble in alcohol, and when distilled yields picoline (methyl pyridine) (A.
When heated they liquefy; and if the heating be continued, the water of crystallization is driven off, the salt froths and^swells, and at last an amorphous powder remains.
It is a white amorphous infusible powder, which when strongly heated in sulphuretted hydrogen, yields an oxysulphide.
1899, 20, p. 34 1), as a yellow amorphous powder by the action of dilute sulphuric acid on the potassium salt, which is formed when columbic acid is fused in a silver crucible with eight times its weight of caustic potash (loc. cit.).
Exposed to air this mixture is oxidized to the pigment uranium red, U6(NH4)2S09, which is a fine blood-coloured amorphous powder.
Haemosiderin, an iron-containing pigment (probably an hydrated ferrous oxide), is found in more or less loose combination with protein substances in an amorphous form as brownish or black granules.
The element exists in two forms, one amorphous, the other crystalline.
The older methods used for the preparation of the amorphous form, namely the decomposition of silicon halides or silicofluorides by the alkali metals, or of silica by magnesium, do not give good results, since' the silicon obtained is always contaminated with various impurities, but a pure variety may be prepared according to E.
The specific gravity of the amorphous form is 2.35 (Vigouroux), that of the crystalline variety varying, according to the method of preparation, from 2.004 to 2.493.
It crystallizes in needles which decompose at "4° C. Silicon amide, Si(NH 2) 4, is obtained as a white amorphous unstable solid by the action of dry ammonia on silicon chloride at -50° C. (E.
Gold, silver, copper, lead, aluminium, cadmium, iron (pure), nickel and cobalt are practically amorphous, the crystals (where they exist) being so closely packed as to produce a virtually homogeneous mass.
By acting with hydrochloric acid on glucose Fischer obtained isomaltose, a disaccharose very similar to maltose but differing in being amorphous and unfermentable by yeast.
When heated to about 200° it yields a brown amorphous substance, named caramel, used in colouring liquors, &c. Concentrated sulphuric acid gives a black carbonaceous mass; boiling nitric acid oxidizes it to d-saccharic, tartaric and oxalic acids; and when heated to 160° with acetic anhydride an octa-acetyl ester is produced.
Contemporaries usually spoke of 70, 72, 73 or 77 members, and perhaps the list is complete with Daenell's recent count of 72, but the obscurity on so vital a point is significant of the amorphous character of the organization.
The metal thus produced formed a dark brown amorphous powder resembling iron as obtained by the reduction of its oxide in hydrogen.
Amorphous titanium oxide may be obtained in a pure form.
It gives the normal sulphate as a yellow, deliquescent, amorphous mass when treated with nitric acid.
It is a white amorphous powder which resembles lime in its general character.
By heating the amorphous form in the electric furnace H.
The amorphous form readily slakes with water, and the aqueous solution yields a crystalline hydrated hydroxide approximating in composition to Sr(OH) 2.8H 2 O or Sr(OH) 2.9H 2 O, which on standing in vacuo loses some of its water of crystallization, leaving the monohydrated hydroxide, Sr(OH) 2 H 2 O.
It may be obtained crystalline by fusing the anhydrous chloride with a large excess of potassium hydrogen fluoride or by heating the amorphous variety to redness with an excess of an alkaline chloride.
It is a colourless, amorphous solid, which is almost insoluble in water, its solubility diminishing with increasing temperature; it is appreciably soluble in concentrated sulphuric acid.
It is an amorphous solid, insoluble in water, but its solubility is increased in the presence of ammonium nitrate.
Aurous chloride, AuCl, is obtained as a lemon-yellow, amorphous powder, insoluble in water, by heating auric chloride to 185°.
Auric sulphide, Au 2 S 31 is an amorphous powder formed when lithium aurichloride is treated with dry sulphuretted hydrogen at - 10°.
The dichloride is an amorphous, readily fusible, almost black solid.
Tantalum pentoxide, Ta205, is a white amorphous infusible powder, or it may be crystallized by strongly heating, or by fusing with boron trioxide or microcosmic salt.
The bottom of the Black Sea is covered by a stiff blue mud in which Sir John Murray found much sulphide of iron,' grains or needles of pyrites making up nearly 50% of the deposit, and there are also grains of amorphous calcium carbonate evidently precipitated from the water.
It is, however, a curious question how, considering the increase of carbonic acid by the decomposition of organic bodies and possible submarine exhalations of volcanic origin, the water has not in some places become saturated and a precipitate of amorphous calcium carbonate formed in the deepest water.
Coal is an amorphous substance of variable composition, and therefore cannot be as strictly defined as a crystallized or definite mineral can.
The amorphous metal also results when the chloride is heated with sodium; the oxide reduced with magnesium; or when fused potassium zircono fluoride is electrolysed (Wedekind, Zeit.
Zirconia can be obtained crystalline, in a form isomorphous with cassiterite and rutile, by fusing the amorphous modification with borax, and dissolving out with sulphuric acid.
Calcium monosulphide, CaS, a white amorphous powder, sparingly soluble in water, is formed by heating the sulphate with charcoal, or by heating lime in a current of sulphuretted hydrogen.