156 



A HISTORY OF 



fail to unfit us for their accidental encoun- 

 ter. 



Upon the whole, therefore, man is less able 

 to support hunger than any'other animal ; and 

 he is not better qualified to support a state of 

 watchfulness. Indeed, sleep seems much 

 more necessary to him, than to any other crea- 

 ture : as, when awake, he may be said to ex- 

 haust a greater proportion of the nervous fluid ; 

 and, consequently, to stand in need of an ade- 

 quate supply. Other animals, when most 

 awake, are but little removed from a state of 

 slumber ; their feeble faculties, imprisoned in 

 matter, and rather exerted by impulse than de- 

 liberation, require sleep, rather as a cessation 

 from motion, than from thinking. But it is 

 otherwise with man ; his ideas, fatigued with 

 their various excursions, demand a cessation, 

 not less than the body, from toil : and he is 

 the only creature that seems to require sleep 

 from double motives ; not less for the refresh- 

 ment of the mental, than of the bodily frame. 



There are some lower animals, indeed, that 

 seem to spend the greatest part of their lives 

 in sleep ; but, properly speaking, the sleep of 

 such may be considered as a kind of death ; 

 and their waking, a resurrection. Flies, and 

 insects, are said to be asleep, at a time that all 

 the vital motions have ceased, without res- 

 piration, without any circulation of their juices; 

 if cut in pieces, they do not awake, nor does 

 any fluid ooze out at the wound. These may 

 be considered rather as congealed than as 

 sleeping animals ; and their rest, during win- 

 ter, rather as a cessation from life, than a ne- 

 cessary refreshment ; but in the higher races of 

 animals, whose blood is not thus congealed, 

 and thawed by heat, these all bear the want 

 of sleep much better than man ; and some of 

 them continue a long time without seeming to 

 take any refreshment from it whatsoever. 



But man is more feeble ; he requires its due 

 return ; and if it fails to pay the accustomed 

 visit, his whole frame is in a short time thrown 

 into disorder : his appetite ceases ; his spirits 

 are dejected ; his pulse becomes quicker and 

 harder ; and his mind, abridged of its slumber- 

 ing visions, begins to adopt waking dreams. 

 A thousand strange phantoms arise, which 

 come and go without his will ; these, which 

 are transient in the beginning, at last take firm 

 possession of the mind, which yields to their 

 dominion, and after a long struggle, runs into 



confirmed madness. In that horrid slate, the 

 mind may be considered as a city without 

 walls, open to every insult, and paying ho- 

 mage to every invader ; every idea that then 

 starts with any force, becomes a reality ; and 

 the reason, over fatigued with its former im- 

 portunities, makes no head against the tyran- 

 nical invasion, but submits to it from mere 

 imbecility. 



But it is happy for mankind, that this state 

 of inquietude is seldom driven to an extreme ; 

 and that there are medicines which seldom 

 fail to give relief. However, man finds it 

 more difficult than any other animal to pro- 

 cure sleep : and some are obliged to court 

 its approaches for several hours together, be- 

 fore they incline to rest. It is in vain that all 

 light is excluded ; that all sounds are re- 

 moved ; that warmth and softness conspire 

 to invite it ; the restless and busy mind still 

 retains its former activity; and Reason, that 

 wishes to lay down the reins, in spite of her- 

 self, is obliged to maintain them. In this dis- 

 agreeable state, the mind passes from thought 

 to thought, willing to lose the distinctness of 

 perception, by increasing the multitude of 

 the images. At last, when the approaches 

 of sleep are near, every object of the imagi- 

 nation begins to mix with that next it; their 

 outlines become, in a manner, rounder ; a 

 part of their distinctions fade away; and 

 sleep, that ensues, fashions out a dream from 

 the remainder. 



If then it should be asked from what cause 

 this state of repose proceeds, or in what man- 

 ner sleep thus binds us for several hours to- 

 gether ? I must fairly confe'ss my ignorance ; 

 although it is easy to tell what philosophers 

 say upon the subject. Sleep, says one of 

 them," consists in a scarcity of spirits, by 

 which the orifices or pores of the nerves in 

 the brain, through which the spirits used to 

 flow into the nerves, being no longer kept 

 open by the frequency of the spirits, shut of 

 themselves ; thus the nerves, wanting a new 

 supply of spirits, become lax, and unfit to con- 

 vey any impression to the brain. All this, 

 however, is explaining a very great obscurity 

 by somewhat more obscure ; leaving, there- 

 fore, those spirits to open and shut the en- 



Rohauh. 



