18, 4 Perkins: The Structure of the Electron 333 
ing an arithmetically correct hydrogen atom, and Parson * 
and Webster ** in suggesting a possible physical basis for the 
supposed discrepancies between radiation and the classical 
theory. Lewis * and Langmuir ** have succeeded in establish- 
ing the gross structure of the atom by a judicious combination 
of physical and chemical data. 
THE REAL PROBLEM 
A man looking through a telescope may fail to see what is 
in his hand. Therefore, it is necessary to state a problem before 
we can work at it intelligently. Some persons enjoy delving 
into the effects which an object produces, and others, into the 
construction of the object. Now each of these points of view 
is necessary for the advancement of science. Hither without 
the other is absolutely helpless. We know nothing of objects 
except from their effects, and on the other hand the most pro- 
found mathematician could never disregard structure entirely 
and write an equation representing the summation of the effects 
of the universe upon his consciousness at any instant.” 
Although it is impossible to prove on a basis of pure logic that 
we can obtain a true conception of any object in the universe it 
is equally impossible to prove that we cannot. Common-sense 
logic not only tells us that.we can, but has justified its stand 
by the present development of science, which would have been 
absolutely impossible without it. 
Now common sense must always be open to correction, but 
it has always divided objective realities into two classes, which 
may be called independent and dependent. A rifle bullet, for 
example, exists independently of its kinetic energy, but common- 
sense logic tells us that kinetic energy is a property which the 
bullet may or may not possess. We can say that the. bullet has 
kinetic energy, or momentum, or entropy, or a property defined 
as energy divided by entropy, or a property defined as accelera- 
tion multiplied by radius, and so on ad infinitum, but it is still 
the same bullet. There is no possibility of denying that certain 
‘9 * Parson, A. L., Smithsonian Miscellaneous Collections 65 ( 1915-6) 
ue Wilnia? D. L., Proc. Am. Acad. 50 (1915) 131; Phys. Rev. 13 (1919) 
= owls, G. N., Journ. Am. Chem. Soc. 38 (1916) 762. 
eS ¢ Langmuir, I., Journ. Am. Chem. Soc. 41 (1919) 868, 1543; 42 (1920) 
m Except for those times when 3 effect = 0. 
