876 



THE CENTURY BOOK OF FACTS. 



brains, and there are grounds for believing that j tion to each other. As with the bodily powers, 

 an excuse has been sought for idleness, or in- ! the mental are to be increased in magnitude 

 diligence in a valetudinarian habit, in the pop- and energy by a degree of exercise measured 

 ular outcry on this subject which awhile ago ! with a just regard to their ordinary health and 

 attracted much attention. Nevertheless there ; native or habitual energies. Corresponding, 

 can be no room to question the extreme peril | moreover, to the influence which the mind has 

 of "overwork" to growing children and in giving the nervous stimulus so useful in 



youths with undeveloped brains. 



The excessive use of an immature organ ar- 



bodily exercise, is the dependence of the mind 

 upon the body for supplies of healthy nutri- 



rests its development by diverting the energy | ment ; and, in like manner with the bodily 



which should be appropriated to its growth, 

 and consuming it in work. What happens to 

 horses which are allowed to run races too early 

 happens to boys and girls who are overworked 

 at school. The competitive system as applied 

 to youths has produced a most ruinous effect 



functions, each mental faculty is only to be 

 strengthened by the exercise of itself in partic- 

 ular. 



It ought to be universally known, that the 

 uses of our intellectual nature are not to be 

 properly realized without a just regard to 



on the mental constitution which this genera- j the laws of that perishable frame with which 



tion has to hand down to the next, and 

 particularly the next but one ensuing. School 

 work should be purely and exclusively directed 

 to development. " Cramming " the young for 



it is connected ; that, in cultivating the mind, 

 we must neither overtask nor undertask the 

 body, neither push it to too great a speed, nor 

 leave it neglected ; and that, notwithstanding 



examination purposes is like compelling an ] this intimate connection and mutual depend- 

 infant in arms to sit up before the muscles of ! ence, the highest merits on the part of the 

 its back are strong enough to support it in the ' mind will not compensate for muscles mis- 

 upright position, or to sustain the weight of treated, or soothe a nervous system which- se- 

 its body on its legs by standing while as yet vere study has tortured into insanity. To come 

 the limbs are unable to bear the burden im- to detail, it ought to be impressed on all, that 



posed on them. 



A crooked spine or weak or contorted legs is 



to spend more than a moderate number of 

 hours in mental exercise diminishes insensibly 



the inevitable penalty of such folly. Another the powers of future application, and tends to 

 blunder is committed when one of the organs abbreviate life ; that no mental exercise should 

 of the body to wit, the brain is worked be attempted immediately after meals, as the 



at the expense of other parts of the organism, 

 in face of the fact that the measure of general 

 health is proportioned to the integrity of de- 

 velopment, and the functional activity of the 

 body as a whole in the harmony of its compo- 

 nent systems. No one organ can be developed 

 at the expense of the rest without a corre- 

 sponding weakening of the whole. 



Mental Exercise. The same rules and 

 regulations by which exercise may be service- 

 able to the physical system, hold good respect- 

 ing the mental faculties. These, as is gener- 

 ally allowed, however immaterial in one sense, 

 are connected organically with the brain a 

 portion of the animal system nourished by the 

 same blood, and regulated by the same vital 

 laws, as the muscles, bones, and nerves. As, 

 by disuse, muscle becomes emaciated, bone 

 softens, blood vessels are obliterated, and 

 nerves lose their natural structure, so, by dis- 

 use, does the brain fall out of its proper state, 

 and create misery to its possessor ; and as, by 

 over-exertion, the waste of the animal system 

 exceeds the supply, and debility and unsound- 

 ness are produced, so, by over-exertion , are the 

 functions of the brain liable to be deranged 

 and destroyed. The processes are physiologic- 

 ally the same, and the effects bear an exact rela- 



processes of thought and of digestion cannot 

 be safely prosecuted together ; and that, with- 

 out a due share of exercise to the whole of the 

 mental faculties, there can be no soundness in 

 any, while the whole corporeal .system will 

 give way beneath a severe pressure upon any 

 one in particular. These are truths completely 

 established with physiologists, and upon which 

 it is undeniable that a great portion of human 

 happiness depends. 



THE HUMAN PULSE. 



The phenomenon known 



as the arterial 



pulse or arterial pulsation is due to the disten- 

 tion of the arteries consequent upon the inter- 

 mittent injection of blood into their trunks, 

 and the subsequent contraction which results 

 from the elasticity of their walls. It is per- 

 ceptible to the touch in all excepting very minute 

 arteries, and, in exposed positions, is visible to 

 the eye. The pulse is usually examined at the 

 radial artery at the wrist, the advantages of 

 that position being that the artery is very 

 superficial, and that it is easily compressed 

 against the bone. It is usual and convenient, 

 though not quite accurate, to include under 

 the term the conditions observed between the 

 beats, as well as those produced by them. 





