RUB
mata are headed. The fruit is cormpofed of two round bo- dies, fmooth, and firmly joined together. The feeds are fingle, roundifh, and umbilicatcd. Lmnai Gen. flant.
The charaaers of this genus, according to Mr. Tournefort, are thefe. The flower confifts of one leaf, fhaped like a bell, and very open at the mouth, and divided into feveral ferments, and ufually perforated. The cup changes into a fruit compofed of two fucculent berries, which contain ufually an umbilicated feed. The leaves are all fet in run- dies about the {talk, feveral being placed at a joint in form of a radiated ftar.
The fpecies of rubia enumerated by Mr. Tournefort are thefe. i. The common cultivated madder. 2. The great wikbW^rofMontpelier j and 3. The exotic four leaved fhinino- madder. The difpofition of the leaves, about the ftalks of thefe plants, ferve to diftinguifh them from other dalles, when they are not in flower ; and this genus is abundantly diftinguifhed from all the others which have their leaves difpofed in this manner, by its having a berry, or juicy fruit, inftead of the dry fruits of the others. Town, Inft. p. 15. See Madder, Cycl. and Suppi. The root of the common madder cultivated for the ufe of the dyers, is an excellent aperient and diuretic. It is prefcribed with great fuccefs in obftructions of the liver and fpleen, in fuppreifions of the menfes and urine, and in droplies, jaun- dices, and cachexies. It is alfo recommended as a vulne- rary, and faid to be peculiarly excellent in the diffolving co- agulated blood. The dyers prepare a red colour with it, and ufe it alfo as a firft tint for feveral others.
Rubia itteriia, a term ufed by Paracelfus and his follqwers for the erifipelas.
RUBICAN, in the manege. A horfe is faid to be of a rublcan colour, that is a bay, forrel, or black, with a light grey or white upon the flanks ; but fo that this grey or white is not predominant there.
RUBICILLA americana, in zoology, a name given by Mr. Ray to the guiratirica, a Brafilian bird, of the bull- finch kind, very beautifully variegated with red, black and grey. See the article Guiratirica.
RUBICULUS, in ichthyology, a name given by Figulus and ibme others to that fpecies of fiih which we call the roach. It is of the cyprinus kind, and is diftinguifhed by Artedi under the name of the red-eyed cyprinus, with the tail and belly fins red. See the article Cyprinus.
RUB1GO, (Cycl.) in hufbandry, is the name by which the antients expreffed what we call the blight in corn, &c. they gave it this name from the refemblance of the colour of the blighted ftalks to nifty iron.
They generally thought that it came from heaven, being ignorant of its true caufe, which is want of nourifhment in the earth. Virgil gives this up as an incurable diftemper, and tells the farmer, that if his corn is blighted he muft live upon acorns, not fuppofing that any remedy could be devifed for fuch a diftemper.
Palladius gives many receipts to cure the blight, and other diftemperatures of corn that come from above, as they imagined at that time. The chief efficacy of thefe feems to conuft in certain fecret fympathies and antipathies, to fright the clouds away with. The world will eafily judge how likely fuch means as thefe were to have fuccefs. The antient farmers generally ufed prayers, fupplications, and facrifices to their gods on this occafion ; and if thefe did not fucceed, they proceeded to blafphemy and threatenings, and brandifhed bloody axes againft the fky, as a token to their gods to defift from plaguing them, or elfe to expect 110 quarter. They ufed to hang up in their fields and gar- dens, on thefe occafions, pieces of red cloth, and the fea- thers and heart of an owl, as a way to fright the clouds from coming over thofe places. Thefe people in general having no true knowledge of the theory of hufbandry, had recourfe to magic, and ufed what they thought fpells and enchantments on all occafions. Cato, Varro, and even Columella, are full of thefe ridiculous devices. A better knowledge in the real nature of hufbandry, has taught us to understand this matter in a very different manner, and to apply more efficacious remedies to it. Tull's Horfehoing Hufbandry, p. 68. See Blight.
RUBINUS, the ruby, in natural hiftory. See Ruby.
RUBRICA, in natural hiftory, a red earth ufed for marking, and in painting. There are two kinds of it, a harder and a fofter.
The firft, or harder kind, is but little in ufe, except among the turners in wood, as it does not mark fo eafily, requiring to be firft wetted, and then preffed hard upon the fubftance to be marked. This is dug in Lincolnfhire, Hampfhire, and Suflex ; and is a hard and dry earth, of a fomewhat pale red, like the common pale red bricks, and is of a very regular and clofe texture, and always compofed of a num- ber of thin lamina, lying clofely and evenly on one ano- ther. It is of a rough uneven furface, adheres firmly to the tongue, is not eafily broken between the fingers, and ftains the hands a little ; it is of a very aftringent tafte, and melts pretty readily in the mouth. It is very readily diffufible in Suppl. Vol. II.
RUB
water, mouldering to powder, foon after being thrown into it, and makes no effervefcence with acids. The fecond or fofter kind is very common, and put to a number of different ufes. It makes fmiply a very good pale red for the painters, and is very ferviceable to them in their mixed colours. It is in conftant ufe in many parts of the kingdom for the marking of fheep ; and when wafhed and feparated from its fandy particles, is, by fome of our mo- dern druggifts, fold under the name of bole armenic. It is found in many parts of the world ; the beft in England is that from feveral parts of Derbyfhire, from whence the colour-fhops and druggifts of London arc fupplied ; many of the latter thinking this a fhorter method than the com- mon one of our bole armenic makers, of preparing it from a mixture of tobacco pipe clay, and the red ochre called Spa- nifh brown. See Bole and Bolus.
This foft, or common ruddle, is a loofe ponderous earth, of a lax texture, and very friable ; and of a pale, but tolerably bright red, of a fomewhat fmooth and gloffy furface, foit to the touch, adhering firmly to the tongue, eafily broken, between the fingers, and ftaining the hands. It is of a rough auftere tafte, very readily breaks, and falls to powder in water, and makes no effervefcence with aqua fortis. SSU's Hift. of FofT. p. 48. RUBUS, the blackberry bujh, in botany, the name of a genus of plants, the characters of which are thefe. The flower is of the rofaceous kind, being compofed of fe- veral petals, arranged in a circular form on a cup, from the middle of which there arifes a piftil, furrounded with a. great number of itamina ; this finally becomes a fruit of a globular form j compofed, as it were, of a number of fmall berries full of juice j thefe are affixed to a placenta, and contain oblong feeds. See Tab. 1. of Botany, Oafs 21. The fpecies of rubus enumerated by Mr. Tournefort are thefe. 1. The common blackberry bujh with black fruit. 2. The French white flowered blackberry bujh. 3. Thera- bus with double white flowers. 4. The Polifh rubus with- out prickles, and with a large black fruit. 5. The common rubus without prickles. 6. The prickly rubus with the leaves and flower both elegantly divided. 7. The prickly rafpberry bujh. 8. The fmooth rafpberry bujh. 9. The fweet fecnted rubus. 10. The white rafpberry. 11. The creeping rubus with bluifh fruit. 12. The dwarf alpine rubus. 13. The dwarf marfh rubus. 14. The creeping trifoliate rubus, with foft hoary leaves and large blue fruit.
15. The fmall, erect, hoary, white flowered alpine rubus.
16. The trifoliate dwarf upright elegant rubus, with prickles like the rofe-hufh, and a fruit of the colour and tafte of the ftrawberry. To urn. Inft. p. 614.
Rubus, in ichthyology, a name given by Joannes Cuba, Albertus, and fome other writers, to the fpecies of ray, ufually called thzjkaite or f aire. See Raja.
RUBY, rubinus, (Cycl) in natural hiftory, a gem, the di- ftinguifhing character of which is, that it is of a red colour with an admixture of purple.
The ruby, in its^ moft perfect ftate, is a gem of very great beauty, and of equal value. It is often found perfectly pure, and free from all fpots or blemiflies ; but it is much mere frequently debafed by them, and greatly brought down in its value, efpecially in the larger fpecimens. It is of very great hardnefs equal to that of the fapphire, and fecond only to the diamond. It is various in fize, but is lefs fubject to variations in its fhapc than moft of the other gems. It is moft frequently found very fmall ; its common fize being that of the heads of the larger forts of pins j and when of this fize it is very cheap j but it is alfo found of four, fix, and ten carrats ; and fometimes, though but very rarely, up to twen- ty, thirty, or forty; nay, we have accounts of fome of more than an hundred. It is never found of an angular or cry ■ ftalliform fhape, but always of a pebble like figure, often roundifh, fometimes oblong, and much larger at one end than the other, and in fome fort refembling a pear, and is ufually more or lefs flatted on one fide.
It is commonly fo naturally bright and pure on the furface as to need no polifhing ; and is worn in rings, and in the crowns of princes, in its rough or native ftate. Its colour is red -in very different degrees, from the deepeft garnet co- lour to that of the paleft red diamond, but it ever has with the red more or lefs of a purplifh tinge : this is very plainly diftinguifhed in the deeper coloured fpecimens, but in the pale ones is gradually lefs and lefs to be diftinguifhed in pro- portion to their degree of colour. Thefe are the diftinguifh- ing characters of the ruby, and by thefe it is eafily known from the garnet, carbuncle, and other red gems. Our jewellers are very nice, though not perfectly determi- nate in their diftinctions ; knowing this gem, in its different degrees of colour, under three names ; the firft is Amply the ruby : this is the name they give it in its moft perfect and ftrongeft coloured ftate.
The fecond is the fpinal ruby. Under this name they know thofe rubies, which are of a fomewhat lefs deep and greatly lefs vivid colour, than what they call the true ruby t or (im- ply the ruby.
The third is the balafi rubv, a name derived from Balakeia, L 11 th»
