CAEE AND MANAGEMENT OF ANIMALS 813 



of pressure necessary for this is extremely small, as may 

 be demonstrated on the back of the hand ; the white mark 

 left as the result of very slight pressure is a bloodless 

 area. 



Pressure is capable of killing and cutting through any of 

 the tissues of the body ; limbs may be amputated by this 

 means, even the bones cut through. If bone cannot resist 

 pressure, it is easy to understand why skin and muscle 

 suffer. 



In the pressure which produces sore backs both skin, 

 muscle, and bone suffer ; so long as there is a layer of 

 muscle between the skin and the bone, the pressure required 

 to kill skin, has to be exercised for a longer time than that 

 needed to destroy skin where the bone alone is directly 

 beneath, for the muscle acts as an elastic cushion. In 

 those parts of the back, as on the withers and spine, where 

 the skin has the bony framework immediately beneath, both 

 the skin and skeleton may in a very short time suffer to a 

 considerable extent, while where muscle lies between the 

 two, as over the ribs, the time occupied in destroying the 

 skin is greater. 



No living tissues can withstand continuous pressure, even 

 when it is maintained by a relatively soft and elastic sub- 

 stance. It can, therefore, be readily understood the harm 

 that speedily arises when the pressure is brought about by 

 a mechanism of wood and iron, such as a saddle-tree, 

 and the whole forced into the back by the weight of the 

 rider. Just as in friction, an animal in hard condition 

 is better able to withstand pressure than an animal out 

 of condition. 



ISTo matter where the injury occurs, or how it is brought 

 about, friction or pressure, or both combined, are the two 

 exciting causes, and are accountable for all the disorganiza- 

 tion produced. 



The above simple and very obvious statement is full of 

 interest to us, as it explains the many injuries inflicted by 

 saddles or harness. 



So far as we have gone the remarks apply equally to 



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