V E 11 



V E R 



to fuch leaves as have properly an under furface, different 

 in nature from the upper one, and yet ftand upright ; 

 witnefs LaRuca Scariola, and perhaps feveral fucculent 

 leaved plants. 



Vertical Anthers, as in the Tulip, terminate the filaments, 

 and being inferted by one of the extremities, ftand no lefs 

 upright than the filaments themfelves, being oppofed to in- 

 cumbent anthers, whofe infertion is generally lateral, and 

 whofe pofition is more or lefs horizontal, over the ftigma, as 

 in the Paffion-flawer. In both thefe inftances the anthers 

 are remarkably verfatile, anthcr.t •verfatilis ; allowing them- 

 felves to be turned round many times without feparating 

 from the filament. Vertical ftalks, &c. readily explain 

 themfelves. 



Vertical Circle, in AJlrcnomy, is a great circle of the 

 fphcre, pafling through the zenith and the nadir, and any 

 other given point on the furface of the fphere. 



TJie vertical circles are alfo called azimuths ; which fee. 

 The meridian of any place is a vertical circle. All the 

 vertical circles interfeft each other in the zenith and nadir. 



The life of the vertical circles is to meafure the height 

 of the ftars, and their diftances from the zenith, which is 

 reckoned on thefe circles ; and to find their eaftern and 

 weftern amplitude, by obferving h.ow many degrees the 

 vertical, in which the ftar rifes or fets, is diftant from the 

 meridian. 



Vertical, Primr, is that vertical circle, or azimuth, 

 which paffes through the poles of the meridian ; or which 

 is perpendicular to the meridian, and pafles through the 

 equinoftial points. 



Verticals, Prime, in Dialling. See Prime Verticals. 



Vertical of the Sun, is the vertical which pafles through 

 the centre of the fun at any moment of time. 



Its ufe is, in dialling, to find the dechnation of the plane 

 on which the dial is to be drawn, which is done by obferv- 

 ing how many degrees that vertical is dillant from the meri- 

 dian, after marking the point, or line of the Ihadow, upon 

 the plane at any time. 



Vebtical Dial. See Vertical Dial. 



Vertical Line, in Conies, is a right line drawn on the 

 vertical plane, and pading through the vertex of the cone. 



Vertical Line, in Dialling, is a hne in any place per- 

 pendicular to the horizon. 



This is bcft found and drawn on an ereft and reclining 

 plane, by holding up a ftring and lieavy plummet fteadily, 

 and then marking two points of the (hadow of a thread on 

 the plane, a good diilance from one another ; and drawing 

 a line through thofe marks. 



Vertical Line, in Perfpedii-e. See Vertical Line. 



Vertical Plane, in Conies, is a plane pafling through the 

 vertex of a cone, and parallel to any conic feftion. 



Vertical Plane, in Perfpedive. See Flake and Per- 

 spective. 



Vertical Point, in AJlronomy, the fame with vertex or 

 zenitli. 



Hence a ftar is faid to be vertical, when it happens to be 

 in that point which is perpendicularly over any place. 



VERTICILLARIA, in Botany, Fl. Peruv. 69, a 

 Peruvian genus of plants, fo called becaufe its branches are 

 difpofed in regular whorls, one above the other. De Theis. 

 Sec Verticillus. 



VERTICILLAT.E, Whorled-flowered plants, form 

 the 42d natural order in Linnasiis's natural fyftem, being 

 precifely analogous to JufTieu's Labiatje (fee that ar- 

 ticle)^ as well as to the order of D'ldynamia Gymnofpe»mia 

 in the Linnxan artificial fyftem, except that it includes alfo 

 feveral diandrous genera of the latter arrangement. Ray 



firft ettabliftied this order, under the above name, and difttn- 

 guifhed it, though not by a very clear or infallible definition, 

 from his own Afpertfolit. Hermann injudicioufly combined 

 thefe two orders. Linnsus firft clearly defined their dif- 

 ferences. Both have four naked yj-fiij, and a monopetalous 

 corolla ; which is regular in all the Ajperifolia, except 

 EcHirM ; irregular in all the Verticillata, and alfo ringent, 

 or at leaft tvs-o-hpped, except Mextha and Lycopus ; 

 fee thofe articles. The Afpertfolid: have, moreover, alternate 

 or fcattered leaves ; the VerticiUatd oppofite ones ; the former 

 are more of a mucilaginous quahty ; the latter more aro- 

 matic. Linna;us however detected the 'true charafters of 

 the orders in queftion in ihe'njlamens. Thefe in the AJperi- 

 folie are five, all of equal length ; in the Verticillate either 

 four or two ; if four, two are longer, or more perfed, than 

 the reft. 



For the genera which corapofe this order of Verticillatic, 

 and their general characters and properties, the reader is 

 referred to the article Labi,\tje. Their particular mode 

 of inflorefcence is esplair.ed under Verticillus ; though 

 in many inftances their whorls are fo crowded together as 

 to form a fpike, or clufter, the foliage diminilhing, or 

 changing, into braSeas. Of this, examples occur in Salvia, 

 Mentha, and Origanum, with Tome other genera. 



This being one of the moft natural of all the orders in the 

 whole vegetable kingdom, few botanifts have fucceeded in 

 defining its genera. Linnxus has been eminently fuccefsful 

 in this point, having happily feixed fome eflential charaAer 

 by which each genus is clearly maiked, in one part or 

 other of the fruftification ; iuch characters being, on the 

 whole, as well fupported by the habit as can be expected 

 in fo natural an order. 



VERTICILLUS, a Whorl, is a mode of inflorefcence, 

 in which the flowers furround the ftem in a fort of ring. 

 There is feldom a perfetlly whorled infertion of the flowers, 

 around a ftem or ftalk, independent of the leaves, though 

 the rare genus Gxetum, (fee that article,) may afford an 

 inftance. It is moil ufual for each flower to be axillary, or 

 accompanied by a leaf, as in Hippuris. Neverthelefs the 

 natural order of Verticillat.i, fo denominated from this 

 circumftance, is confidered as having truly whorled flowers, 

 though inferted on two oppofite fides of the fquare ftem ; 

 as they, being commonly very numerous and crowded, 

 fpread into one denfe uninterrupted mafs. Such may, or 

 may not, be^ccompanied by leaves or bracteas. 



Folia verticillata, whorled leaves, arc when more than two 

 leaves furround the ftem at one point, or articulation. 

 Examples occur in Galium and its aUies, thence called by 

 Ray and following authors plants Jlellat£ ; as well as in 

 a few of the firft fpecies of Veronica. Peruvian (hrubs 

 are remarkably inclined to bear three or four leaves in a 

 whorl, though the genera, or natural orders, to which thev 

 refpeftively belong, have merely oppofite leaves. See uijdcr 

 the article I^eaf, folia, Una, terna, S:c. 



Whorled Cotyledons are very rare, but they do occur in 

 PiNLS and DoMBEYA. — Even if fuch were, as Juflieu fug- 

 gefts, merely oppofite cotyledons in numerous deep feg- 

 ments, they might perhaps, according to the analogy of the 

 above-defcribed inflorefcence, be called cotyledones verticiUat4i . 



VERTICITY, is that property of the load-ftone by 

 which it turns or direfts itfelf to fome particular point. 



The attraftion of the magnet was known long before its 

 verticity. 



VERTICORDIA, in Mythology, one of the epithets of 

 Venus. See Venus. 



VERTIGO, in Medicine, from -verto, I turn, giddirjfi, 



diT-zinefs, or fivimming cfthe head, a well-known afieftion, in 



9 which 



