August 29, 1913] 



SCIENCE 



289 



hausted. The type of emotion is plainly 

 declared by the activation of the muscles 

 which would be used if the appropriate 

 physical action were consummated. In 

 anger the teeth are set, the fists are 

 clenched, the posture is rigid; in fear the 

 muscles collapse, the joints tremble and 

 the running mechanism is activated for 

 flight ; in sexual excitement the mimicry is 

 as obvious. The emotions, then, are the 

 preparations for phylogenetic activities. 

 If the activities are consummated, the fuel 

 — glycogen — and the activating secretions 

 from the thyroid, the adrenals, the hy- 

 pophysis are consumed. In the activation 

 without action, these products must be 

 eliminated as waste products and so a 

 heavy strain is put upon the organs of 

 elimination. It is obvious that the body 

 under emotion might be clarified by active 

 muscular exercise, but the subject of the 

 emotion is so strongly integrated thereby 

 that it is difficult for him to engage in 

 diverting, clarifying exertion. The person 

 in anger does not want to be saved from 

 the ill-effects of his own emotion ; he wants 

 only to fight ; the person in fear wants only 

 to escape; the person under sexual excite- 

 ment wants only possession. 



All the lesser emotions — worry, jealousy, 

 envy, grief, disappointment, expectation — 

 all these influence the body in this manner, 

 the consequences depending iipon the in- 

 tensity of the emotion and its protraction. 

 Chronic emotional stimulation, therefore, 

 may fatigue or exhaiist the brain and may 

 cause cardiovascular disease, indigestion, 

 Graves's disease, diabetes, and insanity 

 even. 



The effect of the emotions upon the body 

 mechanism may be compared to that pro- 

 duced upon the mechanism of an auto- 

 mobile if its engines are kept running at 

 full speed while the machine is stationary. 

 The whole machine will be shaken and 



weakened, the batteries and weakest parts 

 being the first to become impaired and de- 

 stroyed, the length of usefulness of the 

 automobile being correspondingly limited. 



We have shown that the effects upon the 

 bodily mechanism of the action of the vari- 

 ous ceptors is in relation to the response 

 made by the hrain to the stimuli received. 

 What is this power of response on the part 

 of the brain but consciousness? If this is 

 so, then consciousness itself is a reaction tc 

 environment, and its intensity must vary 

 with the state of the brain and with the en- 

 vironmental stimuli. If the brain cells are 

 in the state of highest efficiency, if their 

 energy has not been drawn upon, then con- 

 sciousness is at its height; if the brain is 

 fatigued, that is, if the energy stored in the 

 cells has been exhausted to any degree, then 

 the intensity of consciousness is diminished. 

 So degrees of consciousness vary from the 

 height maintained by cells in full vigor 

 through the stages of fatigue to sleep, to the 

 deeper unconsciousness secured by the ad- 

 ministration of inhalation anesthetics, to 

 that complete unconsciousness of the en- 

 vironment which is secured by blocking the 

 advent to the brain of all impressions from 

 both distance and contact ceptors, by the 

 use of both local and inhalation anesthetics 

 — the state of anoci-association. 



Animals and man may be so exhausted as 

 to be only semi-conscious. While a brain 

 perfectly refreshed by a long sleep can not 

 immediately sleep again, the exhausted 

 brain and the refreshed brain when sub- 

 jected to equal stimuli will rise to unequal 

 heights of consciousness. The nature of 

 the physical basis of consciousness has been 

 sought in experiments on rabbits which 

 were kept awake from 100 to 109 hours. 

 At the end of this time they were in a state 

 of extreme exhaustion and seemed semi- 

 conscious. If the wakefulness had been 

 further prolonged, this state of semi-con- 



