TH 
POPULAR SCIENCH 
RO fo Exe 
AUGUST, 1910 
THE PAST AND PRESENT STATUS OF THE ETHER* 
By Prorpssor ARTHUR GORDON WEBSTER 
CLARK UNIVERSITY 
N a recent letter to the New York Nation, Professor William James, 
in describing the philosophy of M. Emile Boutroux, makes the 
statement that “theories result from psychological variations, just as 
Roosevelts and Rockefellers result from biological variations.” Of the 
entities of science he says: 
The creative touch of human reason was needed in each case for the extrica- 
tion; and that those particular creations resulted rather than a hundred others 
just as possible, is one of those selective interactions between living minds and 
their environment which can be “‘ understood” when once it has occurred, but 
which no acquaintance with the previous conditions can show to an outsider 
that it was the sole thing possible. 
Considering the prevalence of such philosophical views, and the 
fact that many persons believe that physics is now undergoing a sort 
of crisis, in which many of our most cherished ideas are about to be 
relegated to the scrap-heap, I believe it to be not without profit to con- 
sider the past and present condition of our views with regard to the - 
luminiferous ether, and to cautiously forecast their future. 
Certainly the postulate of the existence of the ether has been until 
very recently one of the fundamentals of physics (including astron- 
omy). At the congresses of arts and sciences held at St. Louis in 
1904, the subject of physics was, like all Gaul, divided into three parts, 
physics of matter, physics of ether, physics of the electron, and al- 
though this division was, I believe, not made by a physicist, this must 
have made little difference. In an interesting book published less than 
a year ago by Sir Oliver Lodge, entitled “'The Ether of Space,” the 
properties of the ether are set forth with a concreteness and dogmatic 
manner that is now becoming unfashionable, and relieves that writer 
*Read at a meeting of the American Philosophical Society, April 22, 1910. 
VOL. LXXvi.—8. 
