326 ^n Essay on Dreaming, including 



tion after another of the brain and nervous system is restored to 

 a state of vigihince and energy: and thus the verification of this 

 conjecture, in conjiuiction with the explanations afforded by the 

 organic theory, will be fully adequate to remove all that has been 

 obscure and inexplicable in these mysterious phenomena. 



These views niav also furnish a hint to physicians on the pro- 

 bable causes of one or two common affections of the head. If 

 the process of assimilation is continued in the brain after a due 

 interval of rest, and that a portion of this viscus is asleep, while 

 the remainder and the organs of the senses are awake, the con- 

 comitant stupor and dulness may well be identified with the most 

 frequent species of head-ache, which scarcely amounts to pain, 

 and is little m.ore than a lethargic and sluggish inertness accom- 

 panied by mental confusion and ineptitude : but if, on the con- 

 trary, the assimilating process is defective, and that the substance 

 of the brain is not suIHciently renewed, a different species of head- 

 ache may be the result ; but it is always attributed to a concur- 

 rent effect — the absence of sleep. It is, however, obvious that 

 iieither this nor the former affection can be confounded with 

 that acuteness of pain which is connected with the over-disten- 

 tion and pressure of the vessels on the brain. 



It is also to be inquired, whether more serious disorders may 

 not be the consequence of disturbance or partial suspension of the 

 process in question. How often is mania preceded by protracted 

 ■watchfulness ? and is not a full allowance of nourishment con- 

 sidered, by the most respectable modern practitioners, as one of 

 the most indispensable requisites in the treatment of insanity? 

 and is not the return of intellect in general preceded by the re- 

 storative action of sleep ? It may indeed be maintained by an 

 advocate of the organic theory, that madness is sufficiently ac- 

 counted for by the protracted over-excitement of a particular or- 

 gan ; but this very over-excitement, according to the hypothesis, 

 causes the absorption and waste of some portion of the brain ; and 

 its protracted duration may interrupt the healthy action of that 

 very process, which alone can renew the exhausted substance 

 whose instrumentality is necessary to the operations of the mind. 

 If the healthy action of this process can be restored, it is accom- 

 panied by refreshing reinvigorating sleep; and in numerous cases, 

 if the natural consequence is the returning health and sanity of 

 the patient, in others we may be disappointed, should the ma- 

 lady have proceeded so far as to injure or destroy the organiza- 

 tion on which the intellect depends. It is by no means, how- 

 ever, contended that the cause assigned will account for every 

 species of mental derangement ; and it may, in none of them, be 

 more than a concomitant of some more operative, but unknown 

 cause. 



If 



