VE G
VE 3
( 467 )
all bloffoms, in the pulp of certain fruits, andin many of the flelliy fpindle-ftiaped roots;alfo in the milk of animals, and in human urinein a peculiar difeafed ftate. It is much moreabundant in the vegetable than in the animalkingdom, and by deftructive diftillation affordsa large proportion of empyreumatic acid but noammonia.
Fixed oil; This is contained in moll feeds,and in the pulpy fruit of the olive, the cornel,and perhaps of a few other plants: in animalsit refides in the liver, in cellular membrane, andin milk: it appears to confill of oxygen, hydro-gen and carbon, with little or no azot, andaffords an acid by deftruCtive diftillation.
Albumen , Fibrin and Gelatin : thefe fubfiancesare of extremely rare occurrence in the vege-table kingdom, but they conftitute almoft thewhole of the foft parts of animals: they arecompofed for the mod part of oxygen, hydro-gen, carbon and azot, and afford by diftillationammonia and oil, but no acid.
Benzoic and phofphoric acids: of thefe, theformer is found in the vegetable balfams, andin the urine of the horfe, and of a few otherquadrupeds: the latter, combined with lime,is very abundant in animals, conftituting theprincipal portion of the bones and other hardparts ; but is of comparatively rare occurrencein vegetables, in which it is found in combina-tion with lime or potafh.
All the above vegetable principles may beultimately refolved into the following 15 fub-ftances, viz. oxygen, carbon, hydrogen, azot,fulphur, phofphoric and muriatic acids, ox ydsof iron and manganefe, potafh and foda, lime,magnefia, filex and alumine, and of thefe thefour firft conftitute by far the largeft mafs ofvegetable matter.
As all animal matter is prepared by the pro-cefs of digeftion from vegetables, it is obviousthat each of thefe great claffes of fubftancesmull exhibit in its ultimate analyfis the famefimple fubftances. It is moreover evident fromthe preceding enumeration that not only theelements, but many of the fecondary principlesderived from them are common both to vege-tables and animals, and therefore that ftriftlyfpeaking there can be no effential characters bywhich the chemift can pronounce decifivelyConcerning any unknown fubftance prefentedto his examination, that it belongs to the animalor vegetable kingdom. The old chemifts indeedrelied with confidence on the phenomenaafforded by deftrudtive diftillation: if an am-moniacal liquor was produced accompanied by
the odour of burnt feathers, the fubftance yield-ing it was prefumed to be of animal origin;whereas if an acid liquor was produced accom-panied by the odour of wood-fmoke, the un-known fubftance was confidered as belongingto the vegetable kingdom, and this, though byno means an infallible criterion, mull ftill beconfidered as the bell that can be adopted.VENUS, cryftals of I c ^
VERDITER } See CoppER -VERMILLION. See Mercury.VESUVIAN. Volcanic Schorl, Volcanic Chry-solite, Vefuvian Hyacinth. — Idocraje. Hauy.
Its colour is yellowilh-brown, paffmg intoolive and leek-green, clove-brown, and flelh andhyacinth red.
It occurs in mafs, diffeminated, or cryftallized.The forms of its cryftals are,
1. A ftrait four-fided prifm truncated on theedges and fometimes on the folid angles; whenthe prifm is fhort, the whole figure approachesnear to the cube, and is occafionally even tabular.
2. A ftrait octohedral prifm terminated bytetrahedral pyramids with truncated fummits.
3. A hexahedral prifm with fingle and fome-times double truncatures on the lateral edges, foas to give the cryftal a cylindrical appearance.
The cryftals are middle-fized or fmall, and areeither folitary or in groups, or in drufes; thelateral faces are flightly ftriated longitudinally,the others are fmooth. Externally it has abrightly fliining vitreous luftre 5 internally itsluftre is gliftening and unCtuous. Its fracture isimperfe£tly conchoidal paffmg into fine granularand lamellar. It is ufually more or lefs tranflu-cent; is hard, brittle, and eafily frangible. Sp,gr. 3.36 to 3.42.
It fufes before the blow-pipe without additioninto a yellowilh-green glafs. When ftronglyheated in a charcoal crucible, it forms a denfe
clear nearly colourlefs glafs, with imbeddedgrains pf iron : in a clay crucible it affords adark olive green glafs of confiderable luftre.
Specimens both from Vefuvius and Siberia have been analyfed by Klaproth with the fol-lowing refults.
35.5 —■ 42. Siles
’33. — 34. Lime
22.25 — 16.25 Alumine7,5 — 5.5 Oxydofiron
0.25 — a trace Ditto of manganefe
98-5 — 97-75
It occurs in the lava of Vefuvius accompanied3 » 3