638 



NATURE 



[Oct. 17, 1878 



to a stimulus. He then Avashed out the waste products 

 from it by means of a little salt and water, and found that 

 its contractile po'>yer again returned, just as the power of 

 the steam-engine would be increased by raking the ashes 

 which were blocking up the furnace and putting out the 

 fire. These waste products are partly removed from the 

 muscles by the blood which flows through them, and are 

 carried by the veins into the general circulation. There 

 they undergo more complete combustion, and tend to 

 keep up the temperature of the body. At the same time, 

 however, according to Preyer, they lessen the activity of 

 the nervous system, producing a tendency to sleep, and in 

 this way he would, at least to some extent, explain the agree- 

 able drowsiness which comes on after muscular exertion. 

 It would seem, however, that the circulation of the blood 

 is insufficient to remove all the waste products from the 

 muscles, for we find that they are supplied with a special 

 apparatus for this purpose. Each muscle is generally 

 ensheathed in a thin membrane, or fascia, and be- 

 sides these we have thicker fasciae ensheathing whole 

 limbs. These fasciae act as a pumping apparatus, by 

 which the products of waste may be removed from the 

 muscles which they invest. They consist of two layers, 

 with spaces between. When the muscle is at rest these 

 layers separate and the spaces become filled with fluid 

 derived from the muscle, and when the muscle contracts 

 it presses the two layers of its investing sheath together, 

 and drives out the fluid contained between them. This 

 passes onwards into the lymphatics, where a series of 

 valves prevent its return, and allow it only to move on- 

 wards, till at last it is emptied into the general circula- 

 tion. 



In strong and healthy people the veins and lymphatics 

 together are quite able to take up all the fluid which the 

 arteries have supplied to the muscles, and thus prevent 

 any accumulation from taking place either in them or in 

 the cellular tissue adjoining them, or at least prevent any 

 such accumulation as might become evident to the eye. 

 In delicate, weakly persons, or in those who suffer from 

 certain diseases of the vascular system, this is not the 

 case ; and after standing or walking for a long time the 

 legs become swollen, so that the boots feel tight, and 

 sometimes even a distinct impression may be remarked 

 at that part of the ankle which was covered by the boot. 

 In such persons we can actually see the swelling disap- 

 pear, after the feet have been kept rested for some time 

 on a level with the body, and it may be removed more 

 quickly still by gently and steadily rubbing the limbs in 

 one direction from below upwards. It is almost certain 

 that what we thus see in weakly persons occurs to a 

 slighter extent in all, and that even in the most healthy 

 person after a long walk a slight accumulation of fluid, 

 laden with the products of muscular waste, occurs both in 

 the muscles themselves, and in the cellular tissue around 

 them, even although we cannot detect it by simple in- 

 spection. So long as the limbs of such a person hang 

 down, the force of gravity retards the return both of blood 

 through the veins and of lymph through the fascise and 

 lymphatics, and thus hinders the muscles from getting 

 rid of those waste products which caused the fatigue. 

 When the legs are raised, this hindrance is at once 

 removed, both blood and lymph return more readily from 

 the muscles, carrying with them those substances which 



had been formed by the muscles of the limbs during the 

 exertions which they had undergone when carrying the 

 body about. So long as these substances remained where 

 they had been formed, they might cause in the muscles 

 of the legs an undue amount of fatigue, akhough when 

 distributed over the body generally, they may produce 

 only a pleasing languor. When the legs are long, the 

 obstruction to the return of blood and lymph is of course 

 greater than when they are short, and this return will 

 take place more readily when the legs are raised above 

 the body than when they are only on a level with it. 

 This may be one of the reasons why some of our long- 

 legged American cousins are so fond of raising their feet 

 to a level with their heads, or even higher, although it is 

 very probable that there are reasons still more powerful, 

 which we may discuss at a future time. 



It has already been mentioned that the lymph is pro- 

 pelled along the interstices of the fasciae into the lymphatic 

 vessels by the intermittent pressure which the muscle 

 exerts upon them from within, and it seems natural to 

 suppose that the flow may also be aided by a pressure 

 from without, in the form of shampooing. Even when 

 the hand is rubbed backwards and forwards upon the leg 

 it will relieve fatigue, but the relief is greater when the 

 leg is firmly grasped and the hand moved gently upwards 

 so as to drive onwards as much as possible any fluid 

 which may have accumulated in the limb, and the 

 grasp being then relaxed, the same process should be 

 repeated. 



But while the lymph is thus most readily removed by the 

 pumping action of intermittent pressure either of the hand 

 without or of the muscles alternately contracting and relax- 

 ing within, it seems to us probable that this process may 

 also be aided by steady, constant pressure from without. 

 No doubt it is impossible for such a steady pressure to take 

 the place of the regular pumping action produced by the 

 alternate contraction and relaxation of the muscles when 

 in action, yet it will have a somewhat similar action, 

 though to a very much less extent. For at each beat of 

 the heart, as Mosso shows, the entire limb is distended 

 by the blood driven into the vessels, and during the 

 pauses between the beats it again becomes smaller. 

 Each pulse, therefore, by distending the whole limb and 

 each individual muscle will press out a little of the 

 fluid contained in the fasciae in the same way as the con- 

 tractions of the muscles themselves, and it seems to us 

 probable that it is the aid which is afforded to this process 

 by the gentle pressure exerted on the outside of the legs 

 by a seat which supports them along their whole extent, 

 that renders such a seat so peculiarly restful and agree- 

 able. For an easy chair to be perfect, therefore, it ought 

 not only to provide for complete relaxation of the muscles, 

 for flexion and consequent laxity of the joints, but also 

 for the easy return of blood and lymph not merely by the 

 posture of the limbs themselves, but by equable support 

 and pressure against as great a surface of the limbs as 

 possible. 



Such are the theoretical demands, and it is interesting 

 to notice how they are all fulfilled by the afore-mentioned 

 chair in the shape of a straggling \/\/, which the languor 

 consequent upon a relaxing climate has taught the natives 

 of India to make, and which is known all over the 

 world. 



