B L E 



B L E 



Good venous blood, cxpofcd to the air, is of a dark red 

 colour : when it cools, it feparatcs a thin and altroft colour- 

 lefs feruin, and a thick cake, which has no criift of a dif- 

 ferent colour from the blood below it ; and of which the 

 ferura forms a proportion, amounting to between tl'.e third 

 part and the half. Such blood has no preternatural acri- 

 mony, or Hiline quality ; and in it are found all its conlli- 

 tuent parts in the proper proportions. From this condition 

 of the healthy blood, we m.ay form a judgment of its pre- 

 ternatural iiate, if it be materially changed. 



When the blood remains fo fluid that it will not coagulate, 

 it indicates a deticiency of the gelatinous part, and a great 

 redundance of ferum. Such blood is to be found in many 

 fevers, efpecially in mahgnaut ones, or when the patient is 

 in a very debilitated condition. 



If there be too much ferum in the blood, dropfy and 

 other fi:n lar difeafes are to be apprehended ; for fuch dif- 

 folvcd blood alrt-ys indicates a wtaknefs of the veffels, and 

 of the mufcular fibre. 



When the ferum is yellow, it indicates an obftrufted flow 

 of tilt bile, and its regurgitation into the niafs of the cir- 

 culating fluids. 



When the blood has much fenm and little of the red 

 part, the blood is overloaded with mucus, and it indicates 

 that a cachcftic difeafe is impending ; efpeciiiliy when the 

 ferum has various different colours, and the texture of the 

 cruor is very flender. 



If the blood has its proper and fufficient rednefs and 

 fluidity, but at the fame time exhibits a greafy pellicle, it 

 indicntcj a fuperfiuity of oleaginous particles. 



AVhen it feparates and yields a very compaft, tenacious, 

 vellow, or buffy furface, it is too thick ; and if the ferum 

 be at the fame time fmall in quality, it fliews a great 

 degree of vafcular aftion and inflammation. This is a faft 

 very generally admitted. 



Finally, it is to be obferved, that we need not be alarmed 

 vhen the thicker part of the blood feems to fwim in a 

 milky fluid ; for it commonly happens, in drawing blood 

 only a few hours after a meal, when it proceeds from the 

 chyle, which, about this time, is imperfeftly mixed with the 

 blood. 



We have thrown out thcfe few hints for the attention of 

 prafiical furgeons ; but they are by no means to be re- 

 garded as complete or abfolutely incontrovertible. There 

 is a great deal of fallacy in judgrng from the colour, and 

 other fenfibk qualities of the blood ; and the moderns have, 

 therefore, leatnt to give their opinion with diffidence. This 

 fubjeA is confidercd more at large in a fublequent article. 

 See Blood, and its properties. 



Blei;disg a Horfc, a frequent operation in the Veterinary 

 Art, principally intended to diminifli the mafs of blood, and 

 thereby dellroy the too great fulncfs or over-adion of the 

 heart and arteries. 



When this operation is intended to afFeft the general 

 fyflem, the evacuation is ufuaily made from the jugular 

 vein. For the relief of particular parts, the veffels which 

 belong to it, or which are adjacent to ;t, may be opened ; 

 as the vein running down the infide of the fore-arm is com- 

 mo'.'ly opened wlicn it is conceived the fhoulder is affefted : 

 the uectflity of this operation, on account of injuries of this 

 pK:t, is lefs frequent than is generally imagined : the vein 

 itfclf in g'uersl gives out but little blood, and is very apt to 

 fwell after the operation. 



Aftlelions of the feet are more frequent, and we have often 

 opened the coronary veins with obvious good effedts ; by 

 punfturing with a lancet various parts of the coronary ring, 



Vol. IV, 



the blood flows copioufly, and at length flops of itfelf with* 

 out the leafl ill confequences. 



The vein which encircles the coffin bone is alfo, without 

 much difficulty, opened in inflammations of this part ; the 

 blood flews freely, the artery which accompanies it being in 

 general opened along with it. It is neceffary, in performirg 

 this operation, to remove the horn covering the veffels with 

 a drawing knife till the blood flows in fufficient abundance. 

 The horn round the point of fe&ion fhould be thinned con- 

 fiderably, to prevent irritation, and mild relinous drefhngs 

 fliould afterwards be laid over the part, to exclude the air, 

 &c. 



This operation we have heard condemned by fome, as 

 producing ill confequences, and a fore difficult to heal. 

 We have only to remark, after having frequently performed 

 it, we have not met with an inflance of thcfe ill effedts fol- 

 lowing it. 



The angular veins of the eye are often opened with good 

 effefts in inflammations of this part, as alfo the veflels which 

 are feen paffing over the fclcrotic coats of the eye, and 

 over the duplicature of the membrana cotijtmSiva on the 

 infide of the eye-lids, both of which admit ofeafy fedlion with 

 the lancet. 



The tanporal arter\- alfo prefents itfclf ver)' conveniently 

 for opening in the horfc ; and in inflammations of the brain, 

 or its coverings, or where a fudden depletion of the fyfl:em 

 is defired, it is productive of m.anifeft good effeft. If this 

 vcffel fliould bleed too freely, and apprehenfions are enter- 

 tained of the lofs of too much blood, it is moft eatily flopped 

 by prefTure, or by a deep incifion, which completely fevers 

 the vcffel : in this cafe iti ends foon retracting, flop the farther 

 effufion of blood. 



The veins of the palate are conveniently fituatcd for open- 

 ing, by making a tranfverfe incifion in this part with a lancet, 

 and this is often had recourfe to in the relaxation of the palate, 

 termed lampers, and with apparently good effeft. Some are 

 deterred from the operation, by having experienced a difR- 

 culty in flopping the flow of blood ; a circumflance that in a 

 few times when we have performed this operation, has not oc- 

 curred to u?. 



We fliall now briefly flate the mode of operating, and the 

 confequences which fometimes follow the opening of the 

 jugular vein in horfes. 



It is molt ufual to bleed with the fleam, or the lancet; the 

 former, on account of the thicknefs of the fkiu of the horfe, 

 and the relillance afforded by the hair, is generally had re- 

 courfe to. It is alfo next to inipoffiblc to drive the blade into 

 the neck fo deep as to be injurious, on account of the 

 fliouldcr to which it is affixed; it is perhaps, on this account, 

 the fatcil and moil certain inftruir.tnt, efpecially in the hand 

 of grooms and helpers in flablts, as it cannot be much abufed. 

 In the llrudture of it, the back fliould be particularly at- 

 tended to, for in general this is too narrow, infomuch, that 

 the intlrument being flruck, it finks into the channel of the 

 vein, the prominent mufcles ^f the neck receive the flroke, 

 and the vein is not opened. To remedy this, which is a very 

 common inconvenience, the back of the fleam fhould be at 

 leafl three quarters of an inch broad, in which cafe the opera- 

 tion very rarLly fails. 



The lancet ij alfo very convenient in thin .fkinned horfes, 

 and performs iheoperation very well. It requires, however, 

 on account of the relillaiice of the flsin and liair, to be ufcd 

 rather boldly, as to the length it is prefented with, and the 

 force employed, at leall when a copious flow of blood is 

 defired. 



It is ufiial to wet the hairs over the part intended to be 

 4 G punftiired. 



