32 THE PLEURA. THE WlND-PIPfi. 



lobes, the membrane (pleura) is double, and, from its situation in the midillvt 

 (m medio) is called mediastinum : it forms a passaw for the great blood-vcsseis 

 running near the sjjine, and it is very lial)]e to contract disease, which shows 

 itself in "thick wind," or rather short wind. Sect. 36. In the pleura, then, 

 are wrapped up, as in two silk handkerchiefs, the two lobes of the lungs, the 

 upper part of that membrane l)eing fastened to the spine and ribs ; and on its 

 surface is generated or s-^creted some of that fluid 1 before s[)oke of (sect. 20, 

 21), which is designed to keep the parts moist, and prevent their adhering to- 

 gether. His powers of secretion, however, and those of this organ in par- 

 ticular, often fail in the horse, in consequence of his very great exertions, com- 

 bined with the heat of his blood, exhausting more than the secretory power 

 can supply; and we frequently find the pleura growing to the ribs, the lungs, 

 or the midriff, by reason of its wanting a due portion of this fluid : from the 

 same cause (a defect in the secretion), we sometimes find the upper orifice of 

 the stomach partially attached to the midriflf, evidently caused by inflamma- 

 tion of the parts. But whichsoever of those misfortunes attend the horse, he 

 is invariably " hurt in his wind," suffers much pain at the commencement 

 of a journey, and subsequently, if y)ushed hard, dies of a locked jaw, through 

 excessive suffering. Disorders of this nature were hitherto unknown to far- 

 riers of any description, being mistaken for the worms by every one who has 

 written a book upon horse diseases; and. by the most eminent veterinary au- 

 thor of modern times, the last stages of this mal-conformation are vaguely no- 

 ticed by the erroneous term of " debility," and "general debility," which may 

 mean anything amiss. Whenever the animals that are slain for our suste- 

 nance turn out to have been so aflected, their flesh is rejected by the Jews, 

 under the denomination oi triJLer ; for the whole animal system is entirely af- 

 fected by the horrid circumstance ; the secretory functions in general refuse to 

 perform their share in the production of good and sufficient animal matter, and 

 lentor, or slow fever, is the consequence, as mentioned higher up, in Sec- 

 tion 28. 



33. The wiND-piPK, as its name imports, is the pipe or tube for conveying 

 to the lungs the air which every act of inspiration draws through it. Extend- 

 ing from the throat to the lungs or lights, at their conjunction this tube di- 

 vides into two branches, one penetrating to near the bottom of each lobe, and 

 these again, having a dozen holes a-piece in their sides, inflate an infinite 

 number of little tubes, or pipes, which compose the lungs much in the fashion 

 of sponge. Except eight blood-vessels, which enter the horse's lungs, the 

 intervals are filled with cellular membrane, and these being also connected 

 with the same kind of membrane in all other parts of the body, accounts for a 

 phenomenon, I shall take occasion to notice shortly (sect. 35), in the case of a 

 blown horse. At his upper end, the wind-pipe is composed of strong cartila- 

 ginous plates, connected together by ligaments, and put in motion by small 

 muscles for producing the sounds expressed by the animal. Next to the 

 throat these cartilages, which are there strongest, form a curious kind of cham- 

 ber, termed epiglottis^ over which is a lid or valve, placed there to defend the 

 passage into the air-tube, from the entrance of victuals, drink, &c. For, upon 

 tne descent of any such substances, this valve shuts down like a trap-door, and 

 they pass over it. No sooner, however, are they gone past, than up rises the 

 valve again, lying back towards the mouth upon the palate, and being very 

 large iti the horse, accounts for the gulps with which lie takes in water, and 

 his peculiar mode of feeduig. For the same reason it is, that the liorse 

 breathes only through his nostrils, between which and the wind-pipe th(!re is 

 close affinity in some diseases, and accounts for his incapacity for bellowing 

 like the ox, or vomiting like man. At this spot it is, that certain savages in 

 human shape press the finger and thumb with brutal force, in order, as it in 



