Fkbeuaey 17, 1899.J 



SCIENCE. 



263 



my conduct will be interpreted as my judgment 

 of compensation. The significance of the terms 

 used depends on the fact that there are five 

 essential constants of matter found in every 

 particle of the universe ; these are unity, ex- 

 tension, speed, persistence, and consciousness. 

 If the hypothesis that aflBnity is consciousness 

 and choice fails, and affinity is still unexplained 

 and consciousness is found only in animal bod- 

 ies, then there are but four essentials in inani- 

 mate matter, while there are -five in animate 

 matter, and whenever a new animal body is 

 evolved a fifth essential is evolved. 



If the five essentials of properties are found 

 in every body this should appear not only as 

 afiinity, but it should appear in a series in all 

 bodies. This I have tried to show. I have 

 called the essentials concomitants, and this term 

 seems to offend Mr. Ward, but the term con- 

 comitant is used in the same sense in all modern 

 and scientific psychology. Again, I have tried 

 to show the nature of reciprocality ; as, for ex- 

 ample, when I set forth that quantities or prop- 

 erties that can be measured are the reciprocals 

 of categories, or properties that can be classified. 

 When I come to the second volume I shall 

 greatly multiply these series and shall then 

 systematize them into an argument ; but I shall 

 try not to make a pentalogic series where none 

 exists, as Mr. Ward has done in the tables which 

 he thinks he has compiled from my book. I 

 find scientific men marshalled in three camps — 

 one as champions of idealism, another as cham- 

 pions of dynamism, and a third rejecting all 

 philosophy as vain . I have begun on the attempt 

 to propound a Philosophy of Science. 



J. W. Powell. 



ARTIFICIAL DREAMS. 



To THE Editor of Science : Maury and 

 some others have, to a certain extent, experi- 

 mented on artificial dreams, but, at my instance, 

 my students, Messrs. Matthews and Morley, 

 undertook a series of experiments which may 

 have some value in further illustrating the 

 subject and pointing the way to further work. 

 The method employed was for the one at an 

 early hour in the morning to stimulate sensa- 

 tion in the other for a brief period, often 30 

 seconds, and then waken the dreamer, who at 



once recorded the dream. In general, the 

 dreamer did not know beforehand what stimulus 

 was to be applied. 



The olfactory element in dreams being little 

 recorded by experimenters, particular attention 

 was paid to this point. Smell was slightly 

 stimulated with heliotrope, and visual images 

 mostly resulted, but in ten cases the dream was 

 also olfactory, twice the dream being of a bunch 

 of Violets and of smelling them. In a very 

 strong stimulation of heliotrope the dream was 

 of being choked with smell of perfume. This 

 dream was in its early part composed of re- 

 markable and vivid visual images. The dreamer 

 flew on an air-ship through a snow-storm, and 

 then over a country covered with white enamel 

 and filled with white elephants, one of which 

 pulled down the air-ship but soon released it, 

 and then the whole herd flew oflf ' like so many 

 butterflies.' This imagery has the characteris- 

 tic quality of opium dreams. 



In taste stimulation by salt and water there 

 was a dream of eating olives. 



In stimulating hearing repeatedly with a 

 middle C tuning fork, within an interval of two 

 weeks, a visual-auditory dream was repeated 

 in 'every detail.' A fork in a lower octave 

 gave dream of hearing fog horn, but no visual 

 image. Another time it was the roar of a lion, 

 but no visual image. 



The record gives for temperature stimulation 

 2 pure temperature dreams, and 3 visual and 

 temperature ; for pressure stimulation 2 visual 

 and pressure, for smell stimulation 1 pure 

 smell and 6 pure visual and 10 visual and olfac- 

 tory ; for hearing stimulation 7 pure auditory, 

 6 visual and auditory. 



These reports suggest that artificial dreams 

 may be divided into three classes : First, the 

 simple dream, where the stimulus is removed at 

 the least sign of reaction, and the consequent 

 dream is usually vague and momentary. Second, 

 the cumulative dream, where the stimulus is 

 continued and made to increase to even the 

 highest point of excitation, and the dream has 

 a definite intensifying development till the 

 waking point. (An interesting dream would 

 probably be produced by a metronome brought 

 nearer and nearer, either directly or through a 

 tube connected with the dreamer's ear.) The 



