Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/201

 PAT

PAT

cavities and interfaces of the divided parts of the earth: thefe are of two kinds ; the one natural, the other artificial. By nature the whole earth, or foil, is compofed of parts ; and if thefe had been in every place abfolutely joined, it would have been without interftices or pores, and would have had no in- ternal fuperficies, or pajlure for plants; but fince it is not fo denfe, there muft be thefe interftices at all thofc places where the parts remain feparate or divided. Thefe interftices, by their number and largenefs, determine the fpecific gravity or true quantity of every foil ; the larger they are, the lighter is the foil, and the inner fuperficies anfwers accordingly. The mouths of the vefTels deftined to take in the food or nourifh- ment of the plant, are all fituated on the convex furface of the roots 5 and thefe take their pabulum orfood, which is extreme- ly fmall particles of earth, blended with a due proportion of water, from the fuperficies of the pores ob cavities within which the roots are included.

It is certain that the earth is not diverted of this pabulum by any other means than by the roots of plants, or by actual five; for where no vegetables are fuffered to be, the ground will always grow the richer.

Plough it or harrow it as oft as you pleafe ; let it be expofed to the fun in horfe-paths all the fummer, and to the frofts all the winter ; let it be covered by water at the bottom of ponds and ditches, or grind it to fine powder ; the longer it is expofed or treated by any or all of thefe methods, or any other poilible way, except actual fire be ufed, the more fertile it will be. Thofe particles which are the ^pabulum of plants are fo ex- tremely minute and light, as not to be fingly attracted to the earth, if feparated from thofc parts to which they adhere, or with which they are in contact. They adhere in the earth like daft to the furface of a fmooth clay, which, tho* you turn it up and down, ftill remains in its place, as thefe particles do to thofe parts of the earth, till removed by fome external agent. The proper agent for this purpoie is the root of a plant, but this cannot act upon them unlefs they are firft moiftencd by water; which helps to loofen them, and goes with them into the mouths of the vefTels in the root. It is neceffary a!fo that the nitre of the air come in contact with the matter of this pabulum, in order to relax and render it fit to be feparated and imbibed by the roots of thofe plants which are in the way of it.

As to the fize of the particles of this pabulum of plants, it is not unlikely that the roots may take in no grofter ones than thofe on which the colours of bodies depend ; but to difcover the magnitude of thefe corpufcles, Sir tfaac Newton thinks will require a microfcope that will reprefent things five or fix hun- dred times bigger than they appear to the eye at a foot diftance, and that with fufHeient diftinctnefs.

We are well aflured, that the fine particles of the food of plants, after they have been received into the bodies of plants, do perfpire thro' their pores in a large quantity, and fly off" into the air : this affords us a proof, that they are not to be fepa- rated from the parts of the earth with which they are in con- tact, otherwife than by means of plants ; for if they could, then all our ftirring and digging the earth would make it the poorer, by giving them occafion to evaporate ; the contrary of which is found by experience.

Water alone affords in appearance r.ourifhment to plants, fince they will grow in water ; but this water is allowed never to be free from earth, and that m^kes it fo very nutritive to plants, even when frefli rained down. This is the earthy matter, which is properly the pabulum or food of plants, which is continually in great abundance evaporated from plants and trees into the air, and in a manner fills the whole atmofphere about thern ; this is met by and embodied in the watry vapours in their afcenr, and again brought down to the earth in fhowers of rain with them. Hence it is no wonder, that rain-water proves fo very nutritive to plants, fince it contains the very matter of their food, ready feparated from the reft of the earth, and mixed in that very vehicle with, and by means of which alone it can be received into the bodies of plants, through the mouths of the vefTels of their roots.

The pores, cavities, and interftices of the earth being of two forts, viz. natural and artificial, the one affords the natural, the other the artificial pajlure for plants ; all depending on the different nature of the internal fuperficies of the earth. TitW Horfehoeing Hufbandry. See the article internal Super ficies. PAT A, in zoology, the name by which the Portugueze in Bra- fil call a large and very beautiful American duck, known among others by its Brafilian name, ipecati-apca. It is nearly of the fize of the goofe. See Ipecati-^oa. PAT^CI, in mythology, images of certain gods carried by the Phoenicians on the prows of their gallies. Htffin. Lex. Herodotus, Hb. 4. calls them rSar*t*oS; The word is Phoenician, and derived from pe(hica-> i.e titulus. See Bocbart's Chanaan,\.z, c. 3. but Scaliger does not agree. Morin derives it from Tl&wo;, monkey, this animal having been an object of wor- ship among the /Egyptians, and hence might have been ho- noured by their neighbours. Vid. infra, Mr. Elfner a has lately obferved, that Herodotus does not call the patacij gods ; but that they obtained this dignity from the

liberality of He-fychius and Suidas, and other antient lexico- graphers, who place them at the ftem of mips, whereas Hero- dotus placed them at the prow. Scaliger, Bochart, and Sel- den, have taken fome pains about this fubject. [ a In Mem. de 1'Acad. de Berlin, Tom. 2. p. 379. b Gal Not _ ad Herodot.J

Mr. Morin has alfo given us a learned difTertation on this head, in the Memoires de l'Acad. des Infcript. and Belles Lettres, Tom. r. but Mr. Elfner thinks it defective in point of evidence. He alfo rejects the etymologies of Bochart, Scaliger, and Morin ; he himfelf thinks that tke pataci were the fame as the Diofcuri c, not Caftorand Pollux, invented by the Greeks, but the Diofcuri of oriental and higher antiquity. [ c Children of Jupiter, Aio^apot, or Awftrtpw ; for we may meet with both. See HemJIerhuys in Lucian. Dialog. Deor J Herodotus fays, the patcsci refembled the little fratues of Vul- can. Paufanias tells us they were about a foot high. They were efteemed the proteaors of navigation. See Efner, loc. cit. PATAGONULA, in the Linnsean fyftem of botany, the name of a genus of plants, the charaflers of which are thefe : The cup is an extremely fmall perianthium, divided into five fegments, and remains after the flower is fallen. The flower confifts of a fingle petal, with fcarce any tube, the margin of which is divided into five acute oval fegments. t he ftamina are five filaments of the length of the flower. The authersc are fimpie. The germen of the piffil is oval and pointed. 1 he flyle is flender, and (lightly bifid; its ramifications are alfo bifid again. This is of the fame length with the ftamina, and remains when the flower is fallen. The ftigmata are fimpie The fruit is an oval and pointed capfule, ftanding on a large cup, made up of five long fegments emarginated, or rimed round their edges. The feeds of this plant are yet un- known ; hut the conftruction of the cup in which the capfule ftands is alone a fufficient diflinction for this genus. Linnai Gener. Plant, p. 65. PA TANGHI, in botany, a name by which fome authors have called the tree whofe wood is the logwood, ufed in dyin^ and in medicine. Herm. Muf. Zeyl. p. 4.?. PATE (Cyd.)~ Pate, in zoology, a name given by the people of the northern counties of England to the badger. See the article Taxtjs. PATEE (Cycl.) in heraldry, a term ufed by/ome to exprefs a fort of irregular line, differing from the indented, ingrailed, and all the other regular and common lines, and called by fome the dovetail line.

It is fomewhat like the joint called by our joiners by this laft name, but it is not in general ufe, and is by fome reckoned among what the French call the clatte, a term they have for fuch irregular lines as they find in old engravings or figures, tho' not in ul'e in any arms preferved to this time. Nipet's Heraldry. See Clatte. PATELLA, (CycL)— This is a fmall bone, fituated above the fpine of the tibia, refembling a large chefnut. It is about halt as thick as long, and its length and breadth are nearly 'equal. It is divided into a bafis, apex, and two fides, one convex, the other concave. The bafis is the fuperior and thickeft part of the bone, and is marked with a very confiderable mufcular imprefTion, which runs down for a little way on the convex fide. The apex is obtufe, and ferves for the infertion of a ftrong ligament, which ties the patella to the fpine of the ti- bia. The anterior fide is convex, with fome fmall inequali- ties and furrows upon it. The pofterior fide is concave, co- vered with a cartilage, reaching near the apex, and terminat- ing at an unequal cavity or foftiila, which is an imprefTion for the ligament already mentioned. This cartilaginous fide is parted in two by a ridge which goes between the bafis and apex, and the two parts are exactly Anted to the pulley of the os femoris, the external part being broader than the internal, which is likewife obfervable in the pulley. 7 he patella re- mains long cartilaginous, and in offifying it becomes entirely cellular, except the furfaces of its two fides and the impref- fions. It is connected with the tuberofity of the tibia by a thick fhort ligament; and, indeed, it may be looked upon as belonging in a particular manner to the tibia, or as a move- able olecranum; which again may be looked upon as a fixed patella. Winjlow, s Anat. p. 94. Frafture of the Patella. The patella or knee-pan is much more fubject to a tranfverfe fracture than to one in any other direction. The longitudinal fracture of this bone happens more rarely, but when it does, is much more eafily cured ; becaufe the fragments of the bone in this cafe, generally keep in their right places, but when the bone is broken not only tranfverfely, but into feveral pieces, the cafe is yet more dif- ficult and dangerous. The cure of this fracture muft be at- tempted in this manner: in a longitudinal or perpendicular fracture, the patient muft be laid upon his back, and, extend- ing the foot, the furgeon muft replace the fragments on both fides with the preffure of his hands, binding them up carefully with the uniting bandage; which muft be applied in this cafe in the fame manner with that ufed in large wounds in the belly or forehead. But when the patella is broken tranfverfely, or into feveral pieces, the patient being laid in the fame poflure, and extending his foot as before, the furgeon is with great