SLEEP AND ITS REGULATION. 41 1 



which suffers most, while in deprivation of food it is the brain which 

 preserves longest the integrity of its structure and function. In young 

 animals, abundantly fed and cared for but kept awake, there follows 

 serious lesions of the organism which soon become irreparable, and 

 death results. 



There have been many theories and hypotheses advanced to explain 

 the phenomena of somnolence. The physiologists have here, as so 

 frequently elsewhere, exhibited far more academic than practical in- 

 terest in the matter. There is no subject, however, of greater impor- 

 tance, since it is a prime factor in all the reparative phenomena of 

 life, standing at the foundation of nutrition; yet no research work 

 has been done on the nature of sleep commensurate with the gravity 

 of the subject. Psychologists have written extensively on one phe- 

 nomenon of sleep, viz., dreams. Normal sleep has attracted so little 

 attention that we do not know exactly how to modify it in accordance 

 with common conditions of bodily derangements. Inferentially cer- 

 tain facts seem established which not only account for the phenomena 

 of sleep, but enable us to reason from them and thus to regulate the 

 state in great measure; sometimes sufficiently. It is probable that 

 during sleep there is a diminished resistance in the surface vessels, 

 inducing lowered blood pressure, hence smaller amounts of blood pass 

 through the brain. As sleep approaches the cerebral vessels grow 

 relatively less filled with blood for an hour or more after full som- 

 nolence has come. After reaching its minimum tension the brain 

 circulation remains practically constant for one or two hours or more, 

 gradually returning to normal as the time for awakening nears. 



After having attained a fair idea of what sleep is, whereby we can 

 better appreciate a reasoning from our individual standpoint, we may 

 proceed to discuss its regulation. For the young, who may be assumed 

 to be in possession of full neural and circulatory balance, whether in 

 or out of health, the regulation of sleep is a simple matter, one which 

 will in most instances adjust itself if the subject be placed under 

 normal conditions. 



We may fix our attention most profitably upon the status of sleep 

 in those of middle or late life. Here a number of causes conspire to 

 disturb equilibrium of body cells, sometimes slightly, and at others it 

 will be found that effects have been insidiously wrought which may 

 suddenly obtrude upon our attention, causing great distress, often 

 impairing the integrity of our judgment, hence our working efficiency. 

 Therefore a double peril assails. Mere inability to sleep naturally, or 

 as heretofore, or as each one assumes as a right, is, especially among 

 men (who shrink from admission of physical weakness), seldom re- 

 garded as worth their seeking the advice of a physician. Whereupon 

 the simplest remedy is to hunt about for something which will obtund 



