Apbil 29, 1898.] 



j^amNCK 



605 



alike ; it loses its value as soon as we have 

 a more explicit theory which leaves no impor- 

 tant fact of psychological optics outstanding. 

 I cannot at all assent to Professor Stevens' as- 

 sertion that the theory ' has a good following 

 among psychologists.' 



M. Nicati's theory is contained in a single 

 forty-page article, which has not as yet re- 

 ceived the compliment of an abstract in the 

 Zeitschrift, or the Annie psychologique. M. 

 Nicati and Professor Patten have, as Professor 

 Stevens says (p. 515), a perfect right to the 

 enunciation of their hypotheses if they believe 

 that these add to the intelligibility of the ob- 

 served facts. But the hypotheses must be 

 worked out in fifty fold greater detail, and set 

 upon a fiftyfold wider basis of observation and 

 experiment, before they cease to be the private 

 property of their authors and command general 

 attention. The psychologist must know them 

 in the sense that he must know his literature at 

 large. He is no more disturbed by them, how- 

 ever, than is the biologist by the thousand and 

 one theories of heredity and transmission that 

 have been formulated since the days of pan- 

 genesis.* 



In conclusion, I must ask Professor Stevens 

 and other readers to excuse the dogmatic tone 

 of this communication and to attribute it to 

 limitations of space. References could be given 

 for every statement. I may add that my own 

 conversion to the Hering theory has been ex- 

 ceedingly gradual, the result of a systematic 

 working through of argument and counter- 

 argument, under experimental control ; and 

 that, so far as I am aware, I have absolutely no 

 bias in favor of any theory. There are three 

 or four other theories of vision, not mentioned 

 in these two papers, which I should rate higher 

 than either that of M. Nicati or that of 

 Professor Patten. Psychologists should be 

 grateful to Professor Stevens, not only for rais- 

 ing a general question which concerns both 

 physics and psychology, but for his ' physical ' 

 criticisms upon the Helmholtz theory. 



E. B. TlTCHKNBR."^ 



* M. Nicati's ^hypothesis posits a primary gray- 

 vision, and proceeds with a tri-coraponent color 

 theory on an electrical-physiologieal basis. It is ap- 

 parently a remote offshoot of the Helmholtz theory. 



THE DEBT OF THE WORLD TO PURE SCIENCE. 



To THE Editor of Science : Professor Ste- 

 venson's admirable address, recently published 

 in Science, calls to mind the sometimes forgot- 

 ten fact that there are still those who in consider- 

 ing the labors of science, scornfully ask: "What 

 is the use of all this?" Of all forms of scien- 

 tific propagandism the exhibition of specimens 

 in a scientific museum might seem least likely to 

 bear fruit to financial profit. That even here, 

 however, the practical benefits of science can 

 be demonstrated, the following examples that 

 have recently come under my observation may 

 be cited. They are of no great consequence 

 themselves, but illustrate a principle which un- 

 doubtedly has wide application and, coming to 

 my notice quite. by chance, are probably typ- 

 ical of hundreds of similar instances which 

 occur. 



A government contract was to be let for the 

 building of a breakwater. The filling was re- 

 quired to be rock of a certain toughness and 

 durability. The local contractors, with a una- 

 nimity born either of accident or design, de- 

 clared that it would be necessary to go more 

 than a hundred miles to obtain such rock and a 

 railroad would have to be built to transport it. 

 Their estimates of the cost of the work were 

 made accordingly. There was not time for con- 

 tractors at a distance to explore the region, but 

 one contractor, living two thousand miles away, 

 sent a prospector about in the vicinity of the 

 proposed work, with instructions to forward 

 him samples of such rock as might be suitable 

 for the work, with information as to the quantity 

 of each in sight. These samples the contractor 

 brought to a museum, and by comparison with 

 the specimens there, and consultation with the 

 Curator, learned that one of the rocks collected 

 possessed the required qualities. He also 

 learned that the quantity was probably assured 

 by the fact that it was an eruptive rock of 

 which more could be obtained by deeper quarry- 

 ing. Relying on this information, he made a 

 bid on the work at a price $75,000 lower than 

 any of the other contractors had done. The 

 information he had gained may be credited 

 with having saved the government that 

 amount. 



A company endeavoring to sell stock in a 



