146 ELEMENTS OF PHYSIOLOGY 



sinks in a very short time. Students balanced before and after written 

 examinations, showed that the center of gravity had risen from ^ inch 

 to 2 \ inches. W. G. Anderson, director of the Yale Gymnasium, 

 found that mere thought will send a supply of blood to parts of the 

 body. A man perfectly balanced will find his feet sinking if he goes 

 through leg gymnastics mentally but does not make the movements. 

 The flow of blood to an exercised part is affected by the attitude of mind 

 of the person exercising. If a man exercises in a listless, mechanical 

 manner, the center of gravity is not changed to any extent ; but when 

 a man takes a series of movements in a conscious and highly volitional 

 manner, the increase in the supply of blood to the arms or legs, accord- 

 ing to the movements taken, is very noticeable. If two men exercise 

 the arms and thorax, one standing before a looking-glass, the other not, 

 the former will show a greater rise of the center of gravity than the 

 other, or a richer supply of blood to the parts. The looking-glass aids 

 him in concentrating his mind on the parts exercised. Dr. Anderson 

 also finds that movements in which men take pleasure send blood more 

 abundantly to parts than do movements which are not to their liking. 

 These experiments furnish important conclusions as to the manner of 

 taking exercise, and the kind of exercise to be taken in order to obtain 

 the greatest benefit therefrom. 



2. Unfortunately, the majority of human beings regard the necessity 

 of sweating as a calamity ; and to dodge sweating, to earn one's liveli- 

 hood in some other way, seems to be the special aim of a growing 

 multitude in all civilized lands. But sweating is a blessing in disguise. 

 The Scripture maxim teaches us that if any will not work, neither shall 

 he eat, either from poverty or indigestion. Nature tells us, " They 

 who will not earn an appetite, cannot digest," and further she says with 

 equal emphasis, " He that will not work shall not sleep 1 ' (J. H. Kellogg). 



3. Effect of Exercise on Growth. Henry G. Beyer, M.D., 

 reported observations on the growth of 188 naval cadets who took 

 special systematic exercise, and compared it with the usual growth of 

 cadets of the same age. 



There was an increase in height of more than one inch above that 

 which took place without the special exercise. 



The increase in strength was five times as much as the normal 

 increase. 



There was an increase in weight of 77 pounds in the four years during 

 which the observations were made. 



There was an increase in lung capacity of 1.72 liters. 



