809 



- The human body is a tolerable representation of the centripetal and 

 centrifugal powers of ancient physics. The motion of many of the sys- 

 tems which enter into its structure is directed from the centre to the cir- 

 cumference : it is a real exhalation that carries out the result of the per- 

 petual destruction of the organs ; such is the action of the heart, of the 

 arteries, and of all the secretory glands. Other actions, on the contrary, 

 take their direction from the circumference to the centre ; and it is by 

 their means that we are incessantly deriving from the food we take into 

 the digestive passages, from the air which penetrates the interior of the 

 lungs, and covers the surface of the body, the elements of its growth, and 

 repair. These two motions, in opposite directions, continually balance 

 each other, prevailing by turns, according to the age, the sex, the state of 

 sleep or waking. During sleep, the motions ten'd from the periphery to 

 the centre, (Hipp.) and if the organs that connect us with outward objects 

 are in repose, the inward parts are in stronger exertion. Somnus labor vi- 

 sceribus (Hipp.) A man, aged forty years, taken with a kind of imbecili- 

 ty, remained about a year and a half at the Hospital of St. Louis, for the 

 cure of some scrophulous glands : all that long time he remained con- 

 stantly in bed, sleeping five sixths of the day, tortured with devouring 

 hunger, and passing his short moments of waking in eating 5 his diges- 

 tion was always quick and easy; he kept up his plumpness, though the 

 muscular action was extremely languid, the pulse very weak and very 

 slow. In this man, who, to use the expression of Bordeu, lived under 

 the dominion of the stomach, the moral affections were limited to the de- 

 sire of food and of repose. Oppressed with irresistible sloth, it was ne- 

 ver without great difficulty that he could be brought to take the slight- 

 est exercise. 



Waking may be looked upon as a state of effort and of considerable 

 expenditure of the sensitive and moving principle, by the organs of sen- 

 sation and of motion. This principle would have been soon exhausted 

 by this uninterrupted effusion, if long intervals of repose had not favoured 

 its restoration. This interruption in the exercise of the senses and of 

 voluntary motion, is of duration corresponding to that of their exertion. 

 I have already said, that there are functions of such essential importance 

 to life, that their organs could be allowed but short moments of repose^ 

 but that these intervals are brought so close to each other, that their time 

 is equally divided between activity and repose. The functions which 

 keep up our connexion with outward objects, could not be without the 



influence of such causes of disease as generally invade them during 1 states of debility 

 and exhaustion, or when they are not otherwise acted on eitheir by external or internal 

 stimuli. 



It may be justly asserted that the operations of the system languish in a degree pro. 

 pprtionate to that in which they are deprived of their natural excitements, whether these 

 excitements are food, air, exercise, amusement, 8cc. whether they are coporeal or 

 mental or whether they are external or internal with respect to their modes of exist- 

 ence, and to their manner of operation on the body. When, therefore, the system is 

 deprived of apart of these excitements, of the influence of the mental operations, and 

 of the excitements of sensation and voluntary motion, as it is during 1 sleep, its operations 

 are necessarily more languid and weak, and consequently it is more ready impressed by 

 many during- the waking state. The condition of the night air, in respect to tempera- 

 ture, and the concentration of the moisture and of the terrestrial exhalations in the low- 

 er regions of the atmosphere, especially in particular situations, also contribute to the 

 effect mentioned in the text. Copland. 



