THE BEASOy WHY. 257 



" I am but a little child : I know not how to go out or come in." i KIUGS in. 



goes more steadily through the arteries and veins, and the lungs, which had 

 been purifying the blood 111 its course, partake of the temporary rest. 



Let us rememter that there are two sets of muscles, acting in unison with 

 epxh other, to produce the various motions ; they are known by the general 

 terms of flexors and extensors ; the first enable jis to bend the limbs, the other 

 to bring the limbs back to their former position. The flexors enable us to close 

 the hand, the extensors to open it again. The flexors enable us to raise the foot 

 from the ground the extensors set the foot down again in the place desired. 

 Consider for a moment the nicety with which the powers of these muscles must 

 be balanced, and the harmony which must subsist between them in their 

 various operations. When we are closing the hand, if the extensor muscles did 

 not gradually yield to the flexors if they gave up their hold all at once, tha 

 hand, instead of closing with gentleness and ease, would be jerked together in 

 a sudden and most uncomfortable manner. If, in such a case, you were to lay 

 your hand with its back upon the table, and wish to close the hand, the fingers 

 would fall down upon the palm suddenly, like the lid of a box. Again, consider 

 how awkward it would be in such a case ; our walk through the streets would 

 become a series of jumps and jerks ; when a man had raised his foot, after it had 

 been jerked up, there it would stand fixed for a second before the opposite 

 muscles could put on their power to draw it down again. This case is not at 

 all suppositious : there is a derangement frequently observed in horses, iu 

 which one set of muscles becomes injured, and we may see horses suffering 

 from this ailment, trotting along with one of their legs jerking up much 

 higher than the others, and set down again with difficulty, just in the manner 

 described. 



It is also to be observed that very nice proportions must exist between the 

 sizes of the muscles and the s^es of the bones. If this were not the case, our 

 motions, instead of being firm and steady, would be all shaky and uncertain. 

 In old persons the muscles become weak and relaxed ; hence there is a tendency 

 in the movements of the aged to fall, as it were, together ; the head is no longer 

 erect, the body bends, the knees totter, and the arms lean towards the body as 

 for support. 



In the child a somewhat similar state of things exists. The muscles have 

 not been properly developed, nor have they been brought sufficiently under 

 the controul of the nervous system. The child, therefore, totters and tumbles 

 about, and it is not until it has stumbled and tumbled some hundreds of times 

 in its little history, that the muscles have become strong enough to fulfil their 

 office, or have been brought sufficiently under the controul of the nervous 

 system, to perform well the various duties required from them. 



In all these things, we recognise the perfection of the. divine works. We are 

 apt, too apt, to overlook this perfection, because it prevails in everything; but 

 by speculating upon what inconveniences we might suffer, were not things 

 ordained as they are, we obtain most convincing evidences of divine goodness 

 und wisdom. 



Having taken this view of the muscular system of the external man, let us 

 turn our attention to the muscles of the internal organs. The muscles of whicJ* 

 we have been speaking are called the voluntary muscles, because we have them 

 under our own controul they are subject to the influences of our will. But 

 there is the other set of muscles. STiat are they I W talk of the beating, or o 



