44 



SCIENCE. 



[Vol. XV. No. 365 



room where the pattern of the wall-paper or the carpet abounds 

 in geometrical figures and circles, is apt to find these endowed 

 with gyratory movement, and as a result may come to imagine 

 snakes about him. But the usual causes of this hallucination seem 

 central in origin and due to pre-existing imaginative impulse. Why 

 should this impulse assume the snake form ? May not the explana- 

 tion lie in the facts of nascent consciousness ? We know that 

 stimuli cannot be co-ordinated without some ganglion through 

 which they are brought into relation. In effecting this co-ordina- 

 tion the ganglion must necessarily be subject to the influences of 

 each stimulus and must undergo a succession of changes. This 

 action and its re-action implying perpetual experiences of resem- 

 blances and differences constitutes, according to psychologists, the 

 raw material of consciousness. Therefore, as a corollary of this 

 process, Herbert Spencer asserts, that, as ' consciousness is de- 

 veloped, some kind of instinct becomes nascent.' That there is a 

 nascent instinctive dread of the serpent in man and monkey is ob- 

 vious. There is every reason for it. The early history of our 

 race abounds with record and tradition of that internecine strife 

 between man and the serpent. We find the serpent permeating 

 all his mythology, a chief feature of his legends, inscribed on his 

 monuments, engraved on his symbols, and worshipped as his God. 



" Even before this period the dread of the serpent may have 

 been implanted in our human neuroplasm. Dr. A. E. Brown re- 

 cently made some experiments in the Philadelphia Zoological 

 Gardens, and found that monkeys, who, born and reared within 

 the gardens, had never seen a reptile, yet exhibited great fear and 

 curiosity when a snake was placed in their cage. An alligator or 

 turtle caused no surprise whatever. Other animals, like the ox 

 and the hog, were either perfectly indifferent, or manifested no 

 fear of the snake." 



Dr. Frank W. Brown said : " I cannot altogether agree with the 

 Doctor as to the iitiportant part taken by nascent consciousness in 

 the creation of these hallucinations. I do not think that nascent 

 consciousness enters largely into the formation of the most com- 

 mon of all forms, primary hallucinations ; that is, into those first, 

 simple hallucinations which, if continued (and the majority of them 

 are not), may grow to be more elaborate. Nascent consciousness 

 does, however, have much to do with the elaboration. In the 

 graphic descriptions of the struggles of the legal gentleman it 

 would be interesting to know whether he conceived the snakes be- 

 fore the sentence of the judge, or whether they grew in his con- 

 struction of that sentence ; for in the former case they would be a 

 primary hallucination and in the latter an outgrowth of elaboration. 

 Primary hallucinations, I think, arise largely from misinterpreted 

 perceptions — false cognition. The nerve cells, weakened by con- 

 tinued onslaught of alcohol, no longer possess the power of dis- 

 crimination : they are content to resolve perceptions in the slightest 

 possible way. Just as in that pathological state characterized 

 onomatopoiesis, where the patient lapses into that simple language 

 which names animals by their sounds, so may the weakened nerve- 

 cells of the alcoholic be content, to picture living things at the 

 behest of a suggestive touch. 



"Bugs, ants, mice, and rats are common hallucinations, but they 

 are generally found first on the body and then afterwards in the 

 room and on the furniture. The appearance first on the body can 

 be explained on the supposition that the hallucination was created, 

 by a dermic sensation, or of formication, which would quickly lead, 

 through imperfect cognition, to the conception of a bug or an ant, 

 and then secondarily manifested as a visual hallucination. When 

 seen first on walls or bed, they may be suggested by the so- 

 called musca: zwlitantes, not uncommon in delirium. As a refine- 

 ment of this idea, could not the primary hallucination of snakes be 

 brought about through misinterpretation of a cutis anserzna, 

 which sweeps coldly, wave-like, and rhythmically over a portion of 

 the body? If this process seems complicated, it might explain the 

 infrequency of snakes as an hallucination. Other hallucinations 

 arising in the way I have indicated can be brought about by the 

 red flashes, dust, retinal irritation, which often precedes active 

 delirium, and which suggest a fire, or, more elaborated, a hell ; 

 ringing in the ears, a' cataract, etc. As to the part taken by nas- 

 cent consciousness in the creation of the reptiles in the snalce case 

 given by the Doctor, I might say that he has been a witness against 



himself, in that he has not exaggerated in his vivid description of 

 those miserable forefathers of ours in their sometimes unsuccess- 

 ful attempts to avoid their most uncanny if not most horrible 

 enemy, and from whom we consequently derive one of our most 

 pronounced examples of nascent consciousness. If, then, nascent- 

 consciousness be a leading factor in the production of hallucina- 

 tions, why do snakes so seldom appear as one of their manifesta- 

 tions ? 



" As to the suggestions given by figures on carpets or wall- 

 paper, they create illusions, not hallucinations, as their origin deals- 

 with defective cognition influenced by the imagination, rather thaiv 

 with the nascent consciousness." 



The Sense of Smell. 



There is no other cranial nerve which presents so much to puz- 

 zle the physicist, the anatomist, and the physiologist as the olfac- 

 tory. The course of its fibres, from the nasal mucosa to the cor- 

 tex in the temporo-sphenoidal lobe, is devious and obscure, but the- 

 phenomenon of matter of various kinds imparting the sensation of 

 odor by contact with the periphery of the first nerve is still more 

 mysterious. With regard to light and color and all the sounds of 

 the octave, we have long been able to conceive of their reception 

 and differential appreciation by the cortex as due to vibration and! 

 variation in vibration rates. The wave theory accounts satisfac- 

 torily for these visual and auditory phenomena. 



Theie are some well-known facts concerning the olfactory sense 

 which have always been matters of daily familiarity, but which we 

 have not as yet scientifically interpreted. For instance, as Dr. F, 

 Peterson points out in the New York Medical Journal, some 

 odors, though mingled together, can still be dissociated and recog- 

 nized by the olfactory nerve-ends, whereas others, on the contrary, 

 overwhelrn one another, so that one only may be perceived, the 

 others being completely suppressed. This antogonism has been 

 little studied, and has been generally dismissed by the physiologist 

 under the assumption of a cheinical process occurring in the mix- 

 ture. As illustrating this internecine warfare among smells, the 

 odor of almonds conquers that of musk ; certain ethereal oils 

 destroy the unpleasantness of iodoform ; orris-root is employed 

 against bad breath ; sulphuric ether overcomes Peruvian balsam ; 

 camphor makes the odors of the oils of lemon and juniper, of pe- 

 troleum, of cologne, and of onion disappear; and coffee and cloves 

 have the reputation in our drawing-rooms of being inimical to cer- 

 tain spirituous exhalations. 



There seems, then, to be a sort of strife between odors of vari- 

 ous kinds, a strife inexplicable upon any simply chemical theory ; 

 and it is more than probable that the vibratory hypothesis must 

 needs be accepted to account for the sensation of smell as well as 

 for those of light and of sound. Not long ago Professor Haycroft 

 {Brain, July, 1888) made some investigations upon the olfactory- 

 sense, from which he drew the conclusion that the sense of sn-iell 

 as well as that of taste depended upon the rate of vibration of 

 gaseous particles ; and he found, moreover, a relation existing be- 

 tween the molecular weights and vibrations of bodies and the odors 

 which they exhaled. 



More recently Dr. Zwaardemaker, of Utrecht {Fortschritte der 

 Medicin, Oct. i, 1889), has been studying the same subject in a 

 manner to throw additional light upon the difficult problem. He 

 has constructed an instrument which he calls an olfactometer. It 

 consists simply of a glass tube, one end of which curves upward, 

 to be inserted into the nostril. A shorter movable cylinder, made 

 of the odoriferous substance, fits over the straight end of this glass 

 tube. On inhaling, no odor will be perceived so long as the outer 

 does not project beyond the inner tube. The further we push for- 

 ward the outer cylinder the larger will be the scented surface pre- 

 sented to the in-rushing column of air, and the stronger will be the 

 odor perceived. 



Should one desire to study the effect of mingling two odors, it 

 is only necessary to saturate the cylinder of the olfactometer with 

 one scented body, and another cylinder with another. By the jux- 

 taposition of the ends of the two cylinders, the lengths being ac- 

 curately determined, the air rushing in upon inhalation through 

 the tubes must take up and mingle the two odors. Dr. Swaarde- 

 maker found by this means that whenever one outweighed the 



