WASTE AND REPAIR 173 



a lapse into the less violent exertion of walking, results in 

 a gradual disappearance of that prostration which the run 

 ning produced. This series of illustrations conclusively 

 proves that the rebuilding of the organism is ever making 

 up for the pulling down of it caused hy action ; and that the 

 effect of this rebuilding becomes manifest, in proportion as 

 the pulling down is less rapid. From each digested meal, 

 there is every few hours absorbed into the mass of prepared 

 nutriment circulating through the body, a fresh supply of 

 the needful organic compounds ; and from the blood thus 

 occasionally re-enriched, the organs through which it passes 

 are ever taking up materials to replace the materials used up 

 in the discharge of functions. During activity, the reinte- 

 gration falls in arrear of the disintegration ; until, as a conse 

 quence, there presently comes a general state of functional 

 languor ; ending, at length, in a quiescence which permits the 

 reintegration to exceed the disintegration, and restore the 

 parts to their state of integrity. Here, as wherever there 

 are antagonistic actions, we see rhythmical divergences on 

 opposite sides of the medium state changes which equilibrate - 

 each other by their alternate excesses. (First Principles, 

 96, 133.) 



Illustrations are not wanting of special repair, that is 

 similarly ever in progress, and similarly has intervals during 

 which it falls below waste and rises above it. Every one 

 knows that a muscle, or a set of muscles, continuously strain- 

 ed, as by holding out a weignt at arm s length, soon loses its 

 power ; and that it recovers its power more or less fully after 

 a short rest. The several organs of special sensation yield 

 us like experiences : strong tastes, powerful odours, and loud 

 Bounds, temporarily unfit the nerves impressed by them, for 

 appreciating faint tastes, odours, or sounds ; but these inca 

 pacities are remedied by brief intervals of repose. Yisioi. 

 still better illustrates this simultaneity of waste and repair 

 Looking at the sun so affects the eye that, for a short time, 

 it cannot perceive the ordinary contrasts of light and shade, 



