SNEEZING, SEASICKNESS, PAIN 435 



the scalp. A cold compress by constricting the blood-vessels reduces the 

 din of the multitudinous messages shouted into consciousness by the 

 sense-organs of the scalp. If completely successful it subdues their 

 chorus to its habitual murmur, too faint to secure attention. Long 

 continued, and therefore damaging, contraction of the muscles which 

 move the eye-ball, and particularly its elevator, sends through their 

 protopathic nerves a stream of influence to the mid-brain, with which 

 these nerves are connected, which causes frontal headache in just the 

 same way as the influence which ascends the stomach nerve. 



Would doctors be more logical if they said that the headache was 

 in the hind-brain — the region which contains the agitated gray matter 

 which gives pain- value to the impulses from the scalp — or if they said it 

 was in the stomach ? The irritation of nerve-endings in the stomach is 

 the origin of the trouble, seeing that it sets up the pain-condition in 

 the hind-brain. 



Psychologists base their science upon conspicuous sensations — sen- 

 sations of sufficient prominence to stand out in the field of conscious- 

 ness. They can do no otherwise. But the terminology in which they 

 have expressed the results of their analysis hampers physiology. In 

 the process of conduction a physiologist can distinguish no stages in- 

 termediate between stimulation and muscular response. In reactions 

 to which consciousness is adjunct, as judged by self- feeling, or, when 

 outside oneself by attribution of self-feeling, the nerve-current may 

 be termed a sensation, and sensations may or may not provoke atten- 

 tion. Nothing is gained by classifying the sequence of events into 

 stimulation, passage of impulse, sensation, perception. Such terms are' 

 machinomorphic. The nervous mechanism is infinitely vibrating. " I 

 always hear my clock stop " can have but one meaning. Every tick of 

 the clock produces an answering vibration of the auditory nerve, how- 

 ever little attention be given to the message; and attention carries with 

 it the idea of something which attends. Pain, as pictured in this 

 essay, is the interpretation which the ego gives of hitherto unperceived 

 sensations when they are increased in volume without definition. Pain 

 is developed when impulses, without informing attributes, are raised 

 in urgency to the level of attention. 



The passage of a gall-stone from the gall-bladder to the intestine is 

 the cause of intense pain, " referred," in the first instance, to the skin 

 which overlies the liver. Yet the gall-bladder is insensitive. As sur- 

 geons have long been aware, the liver, stomach and other viscera may be 

 cut, burned, scarified, without arousing pain. Laying stress on these 

 two well-known facts, (1) the insensitiveness of the viscera and (2) 

 their liability to become the source of referred pains, James Mackenzie 

 has defined pain as " a disagreeable sensation due to stimulation of 

 some portion of the cerebrospinal nervous system and referred to the 

 peripheral distribution in the body wall of cerebrospinal sensory 



