Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/622

 TEN

the great apophyfis of the os ocdpkis. Between the apex of the apophyfis petrofa, and the fuperior opening of the carotid canal, we fometimes meet with a fmall bone alfo of the fefa- moide kind, mentioned long fince by Riolan. Almoft the whole fubftance of the ojfa temporum is compact ; the fquam- mous portion is thin and tranfparent ; the maftoide apophyfis is hollowed by confiderable cells -, the apophyfis petrofa is very hard and folid, with feveral internal cavities for the organ of hearing contained in it. JVinjloufs Anatomy, p. 30. See the article Temporis Oj, Cycl.

TENACIOUS Bodies. Seethe article Tenacity.

TENACITY, in natural philofophy, that quality of bodies by which they fultain a confiderable preflure or force without breaking. Mem. Acad. Berlin. 1745. p. 47. Tenacity is the oppofite quality to fragility or brittlenefs. See the article Brit tleness.

Tenacious bodies fupport the effort of percuflion, or preflure, without receiving any damage : But here, and in many other cafes, as when we ufe the words bard-, foft, flexible, &c. we muff be underftood in a fenfe relative to the ordinary degrees of human ftrength ; otherwise it would be difficult to fay, what is tenacious, brittle, hard, foft, &c. Ibid.

TENCH, the Englifh name of the tinea of the modern authors, the fullo and gnapbeus of the antients.

It is, according to the Artedian fyftem, a fpecies of the cypri- nus, and is diftinguiihed by that author by the name of the blackifh, mucous, or flimy cyprinus, with the end of the tail even. See the articles TiNCAand Cyprinus. This is a delicately tatted fifh, though it lives in foul water, and feems to feed very coarfely. It is always found in the muddieft parts of ponds, and where there are moft weeds. The dime of the fkin of this fifh is faid to be of a healing na- ture, and to cure all frefli wounds ; and it is pretended that the <»ther fifh know this property in it, and always apply to the Tench when wounded. Whether their opinion be true or falfe, the Tench has obtained by it the name of the fijhes phyftcian. The pike is faid to pay fuch rcfpeil to this fifh, on this account, that he never feizes him. But thefe are things eafier to be fancied and faid than proved ; and if it mould prove that the pike does not eat the Tench, it may be refolved into a much more natural caufe, by fuppofing the . flime of the Tench too difagreeable in his ftomach to fuffer it. The feafon for angling for Tench is in June, July, and Au- guft. The time of their biting is early in the morning, or late in the evening, and in hot weather, all night long. The favourite bait for the Tench is a large red worm, and they will take this much more greedily if it be dipped in tar, after it is put on the hook. There are feveral forts of parte alfo that he bites very well at, particularly one made of brown bread and honey, with an admixture of tar. All partes that have any of the ftrong-fcented oils in them, are alfo good baits. Other baits are the cad-worm, lob-worm, flag- worm, green gentle, marfh-worm, or foft boiled bread corn. All thefe will do very well at a proper feafon.

When a number of Tench are to be taken out of a muddy pond, where they will not bite freely at the hook, the method is to take a very good and large cafting-net, well leaded, and with the mefhes from the crown to a full yard and halt, not too fmall, for then, if the pond be deep, the fifh will ftrike away before the net gets to the bottom. The place where the net is intended to be thrown, muff be made clean from bufhes and large weeds, with a rake. When the place is thus cleared of any obstacles to the even defcent of the net, a bait is to be prepared to draw the fifh together, where the net is to be thrown. This bait is to be thus made : Put a quarter of a peck of wheat into three quarts of water, fend it to an oven, and let it be well foaked, then add to it five pints of blood, and as much bran as is neceflary to give it the confidence of a pafte. Mixfomc clay with it, that it may the better hold to- gether; and finally add a quart of lobworms chopped to pieces. Let the whole be wrought up into a ftiff pafte, and rolled into balls of the fize of a hen's egg ; and let thefe be thrown into the pond, in the place where the net it to be thrown. At times thefe, and at times feme grains are to he thrown in ; and the place in this manner thoroughly baited for feveral days. When the fifti may be fuppofed to be very well acquainted with the fpot, let a very good baiting be given in the morn- ing, and in the clofe of the evening let the cafting-net be care- fully thrown in. When the net is funk, the mud all about is to be ftirred up with a long pole, with a fork at the end ; the net is to lie half an hour, and the mud to be thus ftirred all the time ; by this means the Tench will be raifed, and will he taken in the pulling out the net ; but if the net were to be thrown in and taken out in the common way, there would hardly be one fifh taken ; for the cuftom of both Tench and carp, when they are frighted, is to plunge their heads up to the eyes in the mud, and thus placed, with their tails creel, any net in the world muft draw over them, without a pofflbi- lity of its entangling them.

TEND, in our old writers, fcems to fignify as much as Tender or offer; as to few/ a traverfe, an averment, &e. Briton, c.76. Staundf. Prarog. 16. Blount, Cswet.

TENDO Achillis, in anatomy, is fometimes more peculiarly - denominated Chorda Achillis, and Chorda Magna, or the great Tendon,

TEN

'Tis on the diftance of the Chorda Achillh from the point of fupport, that the ftrength of the foot depends. The further this tendon is from the articulation, the ftronger the part is found. Hence it is obferved, that animals which run, or leap with the greatcfl eafe, are thofe in which this Tendon is far- theft removed. And men with long heels are better able to walk than others ; and if ill the longer the foot, the more ne- ceflary is the length of heel. Petit, in Mem. de l'Acad. R, des Scienc. 1722. p. 75.

Anatomifts are divided about the rupture of the Tendon of Achillis. Some hold this Toulon impoffible to be broken by any effort whatever, and in proof hereof alledge its fitua- tion, which feems to fecure it from fuch an accident. Others infill, that confidcring the great force which draws this Ten- don downward, when in a leap or fall, the whole weight of the body bears on the top of the foot, or on the heel ; 'tis eafy to conceive, that a fingle effort may break it. Accordingly Pareus affirms, he has known it broken, on a flight occafion ; as by a falfe ftep, a flip in mounting on horfeback ; and this without any vifible injury, or folution of continuity of the part.

M. Petit, the furgeon, produces two other milances of his own knowledge : The nrit, of a pofture-mafter named Clo- choix, who, at the fair of S. Germains, endeavouring to jump, with his feet clofe together, upon a table 3 foot high, broke both the Tendons of Achillis, yet without any external wound n : The fecond, of a woman who broke the Tendon of Achillis of the right foot, by a fall in a boat, from a bench 6 foot high b .—[ a Mem. de l'Acad, R. des Scienc. 1722. p. 68. feq. b Traite des Malad. des Os. Jour des Scav. T. 74. p. 328.]

1 he phenomena enfuing on the rupture of the Chorda Achillis, in thefirft inftance, were, that the patient could ftill contract or ftrctch his feet ; that he could not ftand upright ; and that he felt no pain, either at the time of the rupture, or during the cure.

Notwithstanding this, feveral perfons perflft in the belief of the thing's being impoiTible ; and conteft both thefe inftances, as not real ruptures of the Tendon of Achillis. A warm dif- pute has enfued between the author and Mr. Andry, and others, the particulars whereof are related by the Paris jour- nalifts. V. Jour, des Scav. T. 74. p. 328. feq. Id. T. 75. p. 483. feq. Id. T. 78, p. 230 —

Mr. Petit obferves, that the Tendons are a fort of cords, which at one end part from a mufcle, and at the other are joined to a bone, fo that when the mufcle contracts itfelf in its action, the Tendon draws toward it the bone to which it is infixed, and makes it perform fuch motions as it is capable of. The Tendons are fubftances not capable of extenfion ; fo that when a mufcle acts, if the bone which it mould, by that action, draw to a certain place, does not follow, either the bone muft break, or the Tendon muft be torn afunder ; pro- vided that the action of the mufcle be of a proper ftrength. We are next to confider, that in certain motions, fuch as that of the dancer, who is going to rife up from the ground, all the weight of his body is fuftained by, and even over- powered by a certain number of mufcles, which, having been thrown into a ftrong contraction, violently expand themfelvas again in a moment, and by that means caufe the leap. If at the inftant, when thefe mufcles have ft retched their Tendons to the utmoft violence, there happens fome accident by which thefe Tendons are again pulled downward by the whole weight of the body, it cannot be wondered at, that, ftrong as they are, they cannot refill fo violent a force ; and it was in this very manner that the dancer, cured by Mr. Petit, broke the Tendons. He was about to leap upon a table placed three foot above him; the Tendon could not but be extended to its full power in the attempt ; and in trying, he funk directly down again ; by which means the weight of his whole body was added to the former force ; and that force was yet in- creafed by the acceleration of a fall from the height of three foot.

The Tendo Achillis is formed by an intimate union of the Ten- dons of two mufcles ; now if thefe two Tendons are. both broken, the rupture of the Tendon is judged compleat; if one only is torn, and the ether remains whole, the cafe is then called an imperfect or incompleat rupture of that Tendon. There is a great difference between the compleat and the in- compleat ruptures of this Tendon. The pain in the incom- pleat rupture is exceffively great ; whereas in the perfect one there is fcarce any pain at all. When a Tendon is wholly divided, the two ends draw back different ways, like the firing of a bow when cut, and this produces no pain, or any farther bad fymptom, than the lofs of the Tendon ; which is fo true, that, in order to take off the pain and other bad fymptoms which attend the wounding, or imperfectly dividing a Tendon, the belt means is to cut it wholly afunder. The Tendo Achillis is placed in a fort of focket, where it plays freely every way, and has no connection or adherence with the adjacent parts ; and hence a compleat rupture of it is with- out pain. This, however, is not the cafe, when only one of the two Tendons which compofe it is divided, for then the feparated ends of this retiring back as far as poflible, cannot but violently affect the remaining entire Tendon^ which with

them