THE KIDNEYS. 243 



some obstruction in the ducts or tubes that convey the bile from the liver to the intes- 

 tines. The horse, however, has but one duct, through which the bile usually flows 

 as quickly as it is formed, and there is no gall-bladder in which it can become thick- 

 ened, or hardened into masses so firm as to be appropriately called gall-stones. Jaun- 

 dice does, however, occasionally appear either from an increased flow or altered 

 quality of the bile, or obstruction even in this simple tube. The yellowness of the 

 eyes and mouth, and of the skin where it is not covered with hair, mark it sufficiently 

 plainly. The dung is small and hard ; the urine highly coloured ; the horse languid, 

 and the appetite impaired. If he is not soon relieved, he sometimes begins to express 

 considerable uneasiness ; at other times he is dull, heavy, and stupid. A character- 

 istic symptom is lameness of the right fore leg, resembling the pain in the right 

 shoulder of the human being in hepatic affections. The principal causes are over- 

 feeding or over-exertion in sultry weather, or too little work generally speaking, or 

 inflammation or other disease of the liver itself. 



It is first necessary to inquire whetlier this affection of the liver is not the conse- 

 quence of the sympathy of that organ with some other part, for, to a very considerable 

 degree, it frequently accompanies inflammation of the bowels and the lungs. These 

 diseases being subdued, jaundice will disappear. If there is no other apparent disease 

 to any great extent, an endeavour to restore the natural passage of the bile by purga- 

 tives may be tried, not consisting of large doses, lest there should be some undetected 

 inflammation of the lungs or bowels, in either of which a strong purgative would be 

 dangerous ; but, given in small quantities, repeated at short intervals, and until the 

 bowels are freely opened. Bleeding should always be resorted to, regulated accord- 

 ing to the apparent degree of inflammation, and the occasional stupor of the animal. 

 Plenty of water slightly warmed, or thin gruel, should be given. The horse should 

 be warmly clothed, and the stable well ventilated, but not cold. Carrots or green 

 meat will be very beneficial. Should the purging, when once excited, prove violent, 

 we need not be in any haste to stop it, unless inflammation is beginning to be con- 

 nected with it, or the horse is very weak. The medicine recommended under diar- 

 rhoea may then be exhibited. A few slight tonics should be given when the horse is 

 recovering from an attack of jaundice. 



The Spleen is sometimes very extraordinarily enlarged, and has been ruptured. 

 We are not aware of any means by which this may be discovered, except manual 

 examination by means or the aid of the rectum. The state of the animal would 

 clearly enough point out the treatment to be adopted. 



The Pancreas. We know not of any disease to which it is liable. 



The blood contains a great quantity of watery fluid unnecessary for the nutriment 

 or repair of the frame. There likewise mingle with it matters that would be noxious 

 if suffered to accumulate too much. 



THE KIDNEYS 



Are actively employed in separating this fluid, and likewise carrying off a substance 

 which constitutes the peculiar ingredient in urine, called the nren, and consisting prin- 

 cipally of that which would be poisonous to the animal. The kidneys are two lartre 

 glandular bodies, placed under the loins, of the shape of a kidney-bean, of immense 

 size. The right kidney is most forward, lying under the liver; the left is pushed 

 more backward by the stomach and spleen. A large artery runs to each, carrying not 

 less than a sixth part of the whole of the blood that circulates through the frame. 

 This artery is divided into innumerable little branches most curiously complicated and 

 coiled upon each other; and the blood, traversing these convolutions, has its watery 

 parts, and others the retaining of which would he injurious, separated from it. 



The fluid thus separated varies materially both in quantity and composition, even 

 during health. There is no animal in which itvaries so much as in the horse, — there 

 is no organ in that animal so much under our command as the kidney ; and no medi- 

 cines are so useful, or may be so injurious, as diuretics — such as nitre, and digitalis — 

 not only on account of their febrifuge or sedative effects, but because of the power 

 which they exert. They stimulate the kidneys to separate more aqueous fluid than 

 they otherwise would do. and thus lessen the quantity of blood which the hesrt is 

 labouring to circulate through the frame, and also that which is determined or d-7ven 

 to parts already overloaded. The main objects to be accomplished in these diseases 

 is to reduce the force of the circulation, and to calm the violence of excitement. Diu- 



