INTRODUCTION. 35 



When the coat stares, it is owinor to the scales of the outer skin he- 

 coming dry from the stoppage of perspiration, and turning the hair in 

 different ways : when the coat is smooth and glossy, it is caused by 

 the perspiration rendering the skin moist and supple, and thus per- 

 mitting the hair to take its natural direction. We judge with consi- 

 derable accuracy of the health of the animal by the appearance of the 

 coat, because in health the perspiration flows naturally, and in dis- 

 ease it is unduly increased, or oftener suspended. 



The Organs ff Urine. — The kidneys are two in number, of an oblong 

 shape, situated in the loins on each side of the spine, and imbedded 

 in fat. They are of a red colour, and divided externally into between 

 twenty and thirty distinct lobes, or portions. 



A great quantity of blood is continually circulating through them, 

 and they, being glandular bodies, separate from it a fluid, called urine. 

 The peculiar ingredient of the urine, urea, contains a great quantity 

 of a poisonous substance or gas, called nitrogen. It would therefore 

 seem that the kidney is the organ by which any dangerous excess of 

 nitrogen in the constitution is removed. Besides the urea, nearly 

 twenty different salts and compounds, more or less injurious, have 

 been discovered : so that the kidney is a gland of immense import- 

 ance in preventing the unhealthy accumulation of these matters. It 

 likewise is ready to act instead of any other part of the frame that 

 may happen to be diseased or out of order. When the absorbents 

 are unable to carry off the fluid received into the stomach, or the 

 lungs or the skin refuse to throw off their share of perspirable matter, 

 the kidneys supply their place, and by an increased flow of urine 

 prevent disease and danger. 



The urine is conveyed from the kidneys into the bladder by two 

 canals called the ureters, and it is retained until a sufficient quantity 

 is collected to excite that organ to contract, and to expel its contents. 



The Peritoneum and Caul. — The peritoneum is a strong and exten- 

 sive membrane, lining the internal surface of the belly, and covering 

 all the organs contained therein. It secretes a fluid which keeps the 

 surface of the intestines moist, and thus allows free motion between 

 them ; yet at the same time enwrapping them on every side, each 

 is kept in its proper situation, and strength and support are given to 

 the whole. 



The 0-nenfum, or Caul, is a broad and fatty membrane formed from 

 the peritoneum, and particularly from those portions of it that are re- 

 flected from the paunch. It covers the four stomachs and some of the 

 intestines. Its use is probably somewhat similar to that of the peri- 

 toneum : it supports the intestines, and it prevents them from being 

 injured in the various motions of the body. 



The Uterus and Pregnancy. — Reaching from the external parts of 

 generation in the cow,^ the body of it projecting beyond the bladder, 

 and the two prolongations or horns of it floating loose in the belly, is 

 the uterus or womb, in which the unborn calf is contained and nou- 

 rished. At the extremity of each of the horns of the womb is a small 



