IIORSE-BACK RIDIXG. 1 7 



pointy soon become Incapacitated for most occupa- 

 tions. 



Exercise, on the contrary, increases the strength ; 

 the blood circulates more freely, and with more uni- 

 formity ; the fibres become stronger and more elas- 

 tic ; all the humors receive a more perfect elabora- 

 tion; the nervous fluid separates from the brain in 

 greater quantity, to spread itself through the nerves, 

 and all the functions of the body are performed and 

 movements made with more energy and ease. 



From a medical point of view, movements take 

 place in the muscles, the bones, the tendons, and in 

 all the soft parts of the body. They are divided into 

 three classes : Active, passive, and mixed. 



Active movement or exercise is the one executed 

 voluntarily by the individual alone. In this the body 

 is the sole agent of the movement, as in walking, 

 running, jumping, dancing. All the movements of 

 the thoracic and abdominal members are exercises 

 which result exclusively from muscular contractions. 



In passive exercise the person is moved, not offer- 

 ing the slightest resistance ; or again it may consist 

 in the agitation of the body by means of machines 

 upon which the individual is placed, or which trans- 

 port him from one place to another, such as carriage- 

 driving, etc. 



Most exercises, however, partake at the same time 

 of both of the above-mentioned kinds, and require 

 that the individual, although supported and sub- 



