T H I
when once it is got this way out of it. But if the head of this bone be difplaced outwards, k generally flips upwards at the fame time, it being fcarce poflible but that the very ftrong mufcles of the Thigh muft then draw the bone upwards ; and there is no eminence in this edge of the acetabulum to refill the head of the bone in that paflage.
When the Thigh is diflocated forwards and downwards, which is what moft ufually is the cafe, the leg hangs ftradling out- ward, and is longer than the other ; the knee and foot alfo both turn outwards, and the head of the bone itfelf will be felt near the lower part of the inguen and os pubis. Some- times there is a fuppreflion of urine in this cafe, which is oc- cafioned by fome nerve which communicates with the bladder being violently comprefled ; in the buttock there alfo may be perceived a cavity from the trochanter major, and the reft of the bones being difplaced ; and if the Thigh-bone be not timely re- duced into its acetabulum, the whole limb withers loon after- wards. The patient, for this reafon, can bear little or no ftrefs upon that limb, but muft always incline and throw the weight of his body upon the other ; when he moves forward, he muft move that limb in form of a femicircle, and fupport his body by crutches under the arms ; though there are not wanting particular cafes, where the head of the luxated Tlrigb- bone has grown fo firmly to the adjacent parts, without the acetabulum, as to become, inprocefs of time, fo ftrong as to fupport the body without fttcks, though the perfon could not, in any of the cafes that have been known of this kind, walk without halting.
If the Thigh-bone be difplaced backward, it is ufually drawn upward alfo, as before obferved, at the fame time ; hence there will be perceived, in this cafe, a cavity behind the in- guen, and a tumour upon the buttock, becaufe the head, and trochanter of this bone, will be placed there. The tumour on the buttock being thruft upward, the limb will become (hotter than before, and the foot will be inclined to turn in- wards. The heel will not touch the ground, but the perfon feem to ftand upon his toes ; and laftly, the luxated limb will be much more cafily bent than extended. It is extremely rare that the Thigh is luxated forward or back- ward, without being alfo drawn upward or downward } but if it fhould fo happen, it will yet evidently be difcovered by the rules before given, and by confidering the nature of the arti culation of the bone : As it is, however, at beft very difficult to difcover when the Thigh-bone is diflocated, and when it is fractured, either by feeling or infpedting, becaufe of the great thicknefs of the mufcles and integuments, it is therefore a matter of fome confequence to propofc the figns by which one of thefe cafes may be known from the other. There is reafon to judge the Thigh-bone to be luxated, when we find the liga- ments of the bone have been relaxed by fome preceding con- geftion of humours, when no external violence has been ex- erted upon it, when neither violent pain, tumours, nor in- flammation follow; and laftly, when the whole limb may be bent, and turned about at the acetabulum, without the fur- geon's difcovering any grating or crufhing of the bones; and the contrary of thefe figns, which are what ufually take place, in what have been ufed to be called luxations of this bone, are very ftrong indications of a fracture.
When the bone is found to be really diflocated, it is to be re- duced in a method agreeable to the nature and dire" ion of the dillocation. When it is difplaced forward and downward, the patient is to be laid flat upon his back on a table ; then a lumen napkin, or ftrong fling, is to be made faft about the groin, over the part affected, fo that one end of the fling may come over the belly, and the other over the nates and back, to be both tied together in a knot upon the fbine of the os ileum, and afterwards either faftened to a hook fixed in fome poft, or held firm by fome afliftance : In like manner at the bottom of the Thighs a little above the knee, there muft be faftened ano- ther napkin or fling, or elfe the girt of Hildanus, with a com- prefs between it and the Thigh ; both thefe flings being drawn tight, the Thigh is to be extended, hut that not vehemently ; but only fo much as is fufficient to draw the bone out of its finus, that it may be replaced into its proper acetabulum by the furgeon's hands ; to this purpofe the furgcon is, with one hand, to prefs the head of the Thigh-bone outward, while the other conducts the knee inward. Or the reduction may be made by napkins faftened about the Thigh near its extremities, in the manner of flings, and the limb extended that way, the knee being at the fame time prefTed inward by the hands. If thefe methods are not fufficient, it will be neceflary to have recourfe to the polyfpafton or pulley, well known to the fur- geons on thefe occafions. This is to be the method of re- duction of the Thigh-bone when it is diflocated forward ; but when it is found to be luxated backward, the patient is to be placed flat on a table, with his face downward ; the Thigh is then to be extended more ftrongly than in the former cafe, and the reduction is then to be performed by the furgeon's hand, an affiftant all the while turning the limb fomewhat inwards, and by this method the head of the Thigh-bone generally flips very readily from this fort of diflocation into its proper place. The limb is then to be fecured with proper bandages, and the patient to be kept to his bed for three or four weeks. Heifer ; Surg. p. 167. Suppl. Vol, II.
T H I
Saltzmannus relates an inftance of a luxation of the Thigh-boni, without any fracture of its neck, and confirms what Ruyfch had obferved of the epipbyfis of the os femoris, being as it were annihilated, or at leaft changed fo, as it could not be obferved, when fought after in one who had it broken. Thigh, in the manege. The effect of the horfema
one of the aids that ferves to make a horfe work vigoroufly. See the article Aid.
Fore-thigh, or arm of a horfe, is that part of the fore-leg that runs between the fhoulder and the knee : Though the fore-Thigh does not bend or bow, yet we commonly fay, a horfe goes fine, that bends well the fore-Thigh, importing thereby, that he bends well his leg.
THILYPTKRIS, in botany, a term ufed by Dillenius to ex- prefs the common female fern or brakes. Dill. Cat. 174.
THIMHIO, in the materia medica, a name ufed by fome au- thors for a peculiar fort of lignum aloes, which is blackifh and very heavy, and extremely fweet. Cornell. Syll. p. 87.
THIN, in the materia medica, a name given by the Arabian writers to earth of any kind.
Thus the bole armenic of Galen is called by Avifenna thin armeni ; and hence the word mutbin, an adjective fignifying earthy, or approaching to the nature of earth ; a term applied to many medicines of this kind.
THINA, in botany, a name by which fome authors have cal- led the larix or larch tree. Ger. Emac. Ind. 2.
THIRD (Cycl.)— Third Major. The logarithm, or mea- fure a of the octave ~ being 1 . 000000, the meafure of the greater Third % will be, . 321928. b — [ a See Interval. b Euler. Tentam. Nov. Theor. Muf. p. 109.] The third major is by practitioners cfcen taken for the third part of an octave ; but this is a great error, fince three greater Thirds fall fhort of the octave by adiefis : For -I X ~ X £ x t£t
* ; or by logarithms 3X0. 321928 + log- diefis
. 965784 ~f o . 03421 5 ~ o . 999999 or 1 . 000000 the logarithm of the octave. See the article Diesis.
Third Minor. The logarithm or meafure of the octave \ be- ing 1 . 000000, the meafure of the third minor % will be O . 263034. Hence it appears that four lefler Thirds exceed the octave. But practical muficians are apt to fuppofe them equal to the octave, as they are apt to confound three greater Thirds with that interval. Three lefler Thirds exceed the octave by a diefis and a comma ; as is eafily proved by loga- rithms. Euler. Tent. Nov. Theor. Muf. p. icg. See the article Interval.
Dhninijhed Third, in mufic. We meet with feveral kinds of Thirds in the writings of muficians, as greater and lefs, commonly called fharp and flat ; diminifhed, fuperfluous, de- ficient, and redundant. See the articles Interval, Defi- cient, Redundant, bY.
THIRST (Cycl.) — It is faid, that thofe who travel through the fcorching defarts of Arabia, Perfia, &c. find that brandy, and the ftrongeft wines, quench their Thirjl beft. Boyle, Works abr. vol. 1. p. 52.
THISMA, a name ufed by fome for any fubtcrranean vein, or bed of a mineral.
THISTLE, Carduus, in botany, the name of a genus of plants, the characters of which are thefe ; The flower is of the flofcu- lous kind, being compofed of feveral flofcules, which, at the upper end, are divided into fegments, and ftand upon the em- bryo feed. The general cup which contains thefe flofcules is of a prickly ftrudturej and the embryos finally become feeda winged with down. See Tab. j. of Botany, Oafs 12. The fpecies of Thijlle, enumerated by Mr. Tournefort, are thefe: 1. The calcitrapa, or ftarry-headed Thijlle. 2. The ftarry-beaded Thijlle, with deep purple flowers. 3. The ftarry-headed Thtftk^ with bright red flowers. 4. Theftarry- headed Thiftle with white flowers. 5. The ftarry-headed Thijlle, with broad jagged leaves, and Urge flowers. 6. The ftarry-headed Thijlle, with whole leaves ierrated at the edges. 7. The yellow-flowered ftarry-headed Thijlle, with leaves like the blue-bottle or cyanus. 8. The yellow-flowered ftarry headed Thijlle, with lefs fcaly or prickly heads. 9. The ftarry-headed Thiftle with undivided leaves, and purple flowers. 10. The aflls Thijlle, with fmall heads, or the common wild Thiftle, 11. The broad-leaved fpear-57.>//?/<?. 12. The white-flowered broad-leaved fyear^ThiJlle. 13. The very large and tall exotic (pear-Thiftlr. 14. The very prickly Thijlle, with alaced and prickly ftaiks. 15. The purple- flowered Thiftle with a bending head. 10. The white- flowered Thijlle with a bending head. 17. The bear's-breech Thijlle. 18. The common ladits Thijlle, or milk Thijlle. 19. The ladies Thijlle with no white variegations. 20. The eryngo-like Thiftle with prickly heads. 21. The great exo- tic milk Thijlle, with brown feeds. 22. The galactite Thijlle of John Bauhine. 23. The galadite Thijlle with white flowers. 24. The common woolly Thijlle, with acanthus- leaves. 25. The white- flowered woolly Thijlle with acanthus- leaves. 26. The woolly ncanthus-Thiftle with narrower leaves. 27. The white-flowered woolly narrower- leaved acanthus-Thi/lle. 28. The very tall acanthus-leaved Portugal woolly Thijlle. 29. The Portugal acanthus-leaved woolly Thiftle. 30. The great-flowered Aleppo woolly Thiftle, with acanthus-leaves. 3i.The purple Thijllewith round woolly heads. K k k k 32
