Each of these contains an active substance, which can be obtained in crystalline foi m, and is known as podophyllotoxin.
It is a crystalline body, soluble only in concentrated alcohol.
It is found in European streams, and is caught by anglers, being also a favourite in aquariums. The well-known and important industry of "Essence Orientale" and artificial pearls, carried on in France and Germany with the crystalline silvery colouring matter of the bleak, was introduced from China about the middle of the 17th century.
They are solid crystalline compounds.
Acetamide,, CH 3 ï¿½Conh 2j is a white deliquescent crystalline solid, which melts at 82-83° C. and boils at 222° C. It is usually prepared.
Sainte-Claire Deville obtained a grey product, from which, on dissolving out the aluminium with sodium hydroxide, they obtained a crystalline product, which they thought to be a modification of boron, but which was shown later to be a mixture of aluminium borides with more or less carbon.
Boron fluoride also combines with ammonia gas, equal volumes of the two gases giving a white crystalline solid of composition BF 3 NH 3 i with excess of ammonia gas, colourless liquids BF 3.2NH 3 and BF 3.3NH 3 are produced, which on heating lose ammonia and are converted into the solid form.
It unites readily with ammonia gas forming a white crystalline solid of composition 2BC13.3NH3.
So far as is known, the Malay Peninsula consists of an axial zone of crystalline rocks, flanked on each side by an incomplete band of sedimentary deposits.
Granite is the most widely spread of the crystalline rocks; but dikes of various kinds occur, and gneiss, schist and marble are also met with.
The tin occurs in the form of cassiterite, and is found chiefly in or near the crystalline rocks, especially the granite.
As stream tin it occurs abundantly in some of the alluvial deposits derived from the crystalline area, especially on the west coast.
The bark, very dark externally, is an excellent tanning substance; the inner layers form the quercitron of commerce, used by dyers for communicating to fabrics various tints of yellow, and, with iron salts, yielding a series of brown and drab hues; the colouring property depends on a crystalline principle called quercitrin, of which it should contain about 8%.
The glycols are somewhat thick liquids, of high boiling point, the pinacones only being crystalline solids; they are readily soluble in water and alcohol, but are insoluble in ether.
Good building materials are obtained from many of the rocks of the country, among which the Raialo limestone (a fine-grained crystalline marble) and the Jaisalmer limestone stand pre-eminent.
Cadmium oxide, CdO, is a brown powder of specific gravity 6.5, which can be prepared by heating the metal in air or in oxygen; or by ignition of the nitrate or carbonate; by heating the metal to a white heat in a current of oxygen it is obtained as a dark red crystalline sublimate.
It is a dark-coloured crystalline solid which melts at 194° C. and boils at 268° C. It fumes in moist air and deliquesces gradually.
The coloring matters are not dissolved in the stroma of the chrornoplast, but exist as amorphous granules, with or without the presence of a protein crystal, or in the form of fine crystalline needles, frequently curved and sometimes present in large numbers, which are grouped together in various ways in bundles and give the plastids their fusiform or triangular crystalline shape.
Such crystalline plastitls occur in many fruits and flowers (e.g.
In some cases the plastid disappears and the crystalline pigment only is left.
The crystalline form appears to be due entirely to the carotin, which can be artificially crystallized from an alcohol or ether solution.
But whereas the crystalline form of a chemical substance is stable and fixed, the organized form of a living organism is unstable and subject to change.
There is a foundation of schists and crystalline rocks upon which rests a series of sandstones.
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.
The solid derived from SA is crystalline and soluble in carbon bisulphide, that from S, is amorphous and insoluble.
On cooling it solidifies to a crystalline mass which fuses at - 80° C. (Ruff, ibid.).
It is easily liquefied, the liquid boiling at - 8° C., and it becomes crystalline at - 72.7° C. (Walden, Zeit.
Walden (ibid.) has shown that certain salts dissolve in liquid sulphur dioxide forming additive compounds, two of which have been prepared in the case of potassium iodide: a yellow crystalline solid of composition, KI 14 S0 2, and a red solid of composition, KI 4S0 2.
Sulphur sesquioxide, S203, is formed by adding well-dried flowers of sulphur to melted sulphur trioxide at about 12-15° C. The sulphur dissolves in the form of blue drops which sink in the liquid and finally solidify in blue-green crystalline crusts.
Lavas dip in all directions from the central crystalline core, pointing to the conclusion that the main portion of the mountain represents a single volcanic mass.
The Vavau group consists entirely of coral limestone, which is occasionally crystalline, and contains stalactitic caves of great beauty.
The latest Cretaceous is the Ripley formation, which lies west of the northern part of the last-named, and, about Scooba, in a small strip, the most southerly of the Cretaceous - it is composed of coarse sandstones, hard crystalline white limestones, clays, sands, phosphatic greensands, and darkcoloured, micaceous, glauconitic marls; its greatest thickness is about 280 ft.
Deep. It is characterized by semi-crystalline limestones and blue and white sandy marls.
R 265 at 15° C., possessing a somewhat sweet taste; below o° C. it solidifies to a white crystalline mass, which melts at 17° C. When heated alone it partially volatilizes, but the greater part decomposes; under a pressure of 12 mm.
Large ore-bodies of granular and compact magnetite occur as beds and lenticular masses in Archean gneiss and crystalline schists, in various parts of Norway, Sweden, Finland and the Urals; as also in the states of New York, New Jersey, Pennsylvania and Michigan, as well as in Canada.
The most important subjects of his inquiries are enumerated by Forbes under the following five heads: - (1) The laws of polarization by reflection and refraction, and other quantitative laws of phenomena; (2) The discovery of the polarizing structure induced by heat and pressure; (3) The discovery of crystals with two axes of double refraction, and many of the laws of their phenomena, including the connexion of optical structure and crystalline forms; (4) The laws of metallic reflection; (5) Experiments on the absorption of light.
Eyes are open invaginations without crystalline lens.
RHIPIDOGL0ssA.-Aspidobranchia with a palliovisceral anastomosis (dialyneurous); eye-vesicle closed, with crystalline lens; ctenidia, osphradia and hypobranchial glands paired or single.
Close to them is the remarkable dart-sac ps, a thick-walled sac, in the lumen of which a crystalline four-fluted rod or dart consisting of carbonate of lime is found.
Schists in the common acceptance of that term are really highly crystalline rocks; fissile slates, shales or sandstones, in which the original sedimentary structures are little modified by recrystallization, are not included in this group by English petrologists, though the French schistes and the German Schiefer are used to designate also rocks of these types.
The finely powdered and washed mineral is too crystalline and consequently of insufficient opacity to be used alone as a paint, and is therefore mixed with "white lead," of which material it is also used as an adulterant.
It is a crystalline solid, which melts at 29 0 -30 0 C. and boils at 218°-219° C., and is readily soluble in alcohol and ether.
In the southern region, which is by far the better known, the oldest rocks are granites, crystalline schists and other rocks of Archean aspect.
Ruthenium in bulk resembles platinum in its general appearance, and has been obtained crystalline by heating an alloy of ruthenium and tin in a current of hydrochloric acid gas.
It forms a golden yellow crystalline mass, which sublimes slowly in vacuo, and melts at 25.5° C. It blackens on exposure to moisture, and decomposes when exposed to light.
It is a red-brown crystalline powder, which is soluble in water.
The per-ruthenate, KRuO 4, formed by the action of chlorine on the ruthenate, or of alkalis on the peroxide at 50° C., is a black crystalline solid which is stable in dry air but decomposes when heated strongly.
All four mono-hydroxyxanthones are known, and are prepared by heating salicylic acid with either resorcin, pyrocatechin or hydroquinone; they are yellow crystalline solids, which act as dyestuffs.
To the south of the Nerbudda the Satpura range stretches across the province, containing the greater part of five districts, its crystalline and sandstone rocks rising in places through the superficial stratum of trap, and with large areas of shallow stony land still covered to a great extent with forest interspersed by black-soil valleys of great fertility.
The preparation of crystalline boron in 1856 by Wohler and Sainte Claire Deville showed that this element also existed in allotropic forms, amorphous boron having been obtained simultaneously and independently in 1809 by Gay Lussac and Davy.