530 



SCIENCE 



[N. S. Vol. XXXI. No. 797 



inertia of this body to the inertia of some 

 body selected as a standard; for which 

 purpose he has abstracted the inertia from 

 all other properties of body and is really 

 no nearer the nature of the ultimate ' ' sub- 

 stance" of the body than if he had meas- 

 ured its temperature or its color. 



A most important limitation which 

 might have been entirely forgotten were it 

 not for the metaphysician, is the fact that 

 -phenomena do not constitute the entire 

 subject matter of science. Indeed it is only 

 the mental and physical sciences which 

 deal with phenomena. Human purposes 

 and acts of the human will are quite as 

 much subjects of scientific study, whether 

 we consider the individual, the group or 

 the entire race of sane men, as are any of 

 the phenomena of physics. It includes 

 such branches as history, politics, language 

 and literature. Not only so, but if we de- 

 fine the real as that with which we must 

 reckon in the accomplishment of our pur- 

 poses, this second group of sciences deals 

 with subject matter which is quite as real 

 as anything we consider in physics. 



It will perhaps not be out of place here 

 to repeat the warning given by President 

 Maclaurin^^ to the American Chemical So- 

 ciety on the occasion of the recent Boston 

 Meeting of the American Association for 

 the Advancement of Science. He says : 



We should pay more serious attention than we 

 usually do to the logic of science and have as 

 clear ideas as possible as to what we are really 

 aiming at, as to what we can really expect to do 

 and not to do. A little artificial stimulus toward 

 philosophy might accelerate the process. It seems 

 to me extremely unfortunate that men of science 

 are still so much scared by the bogey of meta- 

 physics. . . . We should realize, perhaps, that a 

 science such as chemistry is above all else a work 

 of art, and that concepts like atoms, energy and 

 the like are not much more than pigments with 

 which we paint our pictures. 



"Boston Herald, December 31, 1909. 



Ether.— One other illustration must 

 serve to complete this ungracious para- 

 graph on limitations. I shall not weary 

 you with citations from Lord Kelvin, tell- 

 ing us how much more we know about the 

 ether than about ordinary matter, but I 

 shall trouble you with a single sentence 

 from ^that skilled expositor. Sir Oliver 

 Lodge,^* whose latest pronouncement upon 

 this subject, omitting, however, the suppo- 

 sitions with which the entire argument is 

 honeycombed, is as follows: 



The estimates of this book and of " Modern 

 Views of Electricity" are that the ether of space 

 is a continuous, incompressible, stationary funda- 

 mental substance or perfect fluid, with what is 

 equivalent to an inertia-coeificient of 10'^ grams 

 per c.c. : that matter is composed of modified and 

 electrified specks or minute structures of ether 

 which are amenable to mechanical as well as 

 electrical force and add to the optical or electric 

 density of the medium: and that elastic rigidity 

 and all potential energy are due to an excessively 

 fine-grained etherial circulation with an intrinsic 

 kinetic energy of the order of 10^ ergs per cubic 

 centimeter. 



Suffice it to say that I am second to no 

 man in this society in my admiration for 

 that group of men Avhose names are asso- 

 ciated with the following dates — 1676, 

 1728, 1820, 1831, 1845, 1864, 1888, Romer, 

 Bradley, Oersted, Faraday, Neumann, 

 Maxwell, Hertz; names and dates which 

 mark the discovery of the finite speed of 

 light, the discovery of aberration, the dis- 

 covery of the magnetic field produced by 

 an electric current, the discovery of the 

 electromotive force produced by magnetic 

 displacement, the mathematical formula- 

 tion of this result by Neumann, the com- 

 bination of these two results by Maxwell 

 and the prediction from them of electric 

 waves, the experimental realization of 

 these waves by Hertz. For brilliancy of 

 achievement this series has certainly sel- 



"" Ether of Space," p. 151, Harper, 1909. 



