FEBRUARY 19, I914| 
NATURE 
689 
long, solitary hours in all manner of wild places, 
we often find vivid descriptions of their ways and 
movements far exceeding in interest those of 
pre-photographic days. 
Some of the best work in the book will be 
found near the end, where the auks are treated 
of, and photos are fewer. We may specially 
notice Mr. Lowe’s attempt to account for the 
“wreck” of countless little auks in February, 
1g12, and on other occasions, by reference to the 
nature of the bird’s oceanic food, which might be 
sunk ,too deep for them by sudden currents of 
cold air reducing the temperature of the surface 
water ; they would thus be driven before the storm 
in search of their usual supplies. My Pycraft a 
few pages further on tries to solve the mystery 
of the guillemot’s egg, but confesses that there 
is no certain explanation. 
‘ 
Fic. 2.—Putting on the brake. 
Fron 
(2) “Bird-Life throughout the Year,” by Dr. 
J. H. Salter, is a pleasant collection of notes, 
some of them unusually interesting, e.g., that on 
the nesting of the dotterel (p, 170). Dr. Salter 
THE RADIATION PROBLEM. 
pH radiation discussion, which was one of the 
most notable features of the Birmingham 
meeting of the British Association, appears to have 
created a general impression that some radical 
revision of our ideas as to the nature of radiation 
must now be regarded as unavoidable. It may 
therefore be of interest to give a brief summary 
of the present state of the problem. 
Its acute phase has been brought about by the 
remarkable successes achieved by some forms of 
what is known as the “theory of quanta.” This 
theory, or rather hypothesis, assumes that not 
only matter, but energy itself, has an atomistic or 
discontinuous structure, particularly when it is 
| lung out into space in the form of radiant energy 
“Our Common Sea-birds.’ 
is a real naturalist, to whom-we are mainly in- | 
debted for the interest aroused in the preservation 
of the kite in South Wales, and his book will be 
a safe and stimulating guide for the young 
beginner. There are some good photographs in it, 
but the coloured ones are not always successful. 
(3) “ Wild Life on the Wing,” by M. D. Havi- 
land, is a collection of stories about teal, wood- 
cock, &c., by one who is not deficient in wood- 
craft, Whether. she is equally an adept in the 
art of telling a tale may be doubted; but the book 
is a pleasant one, and well adapted for a gift. 
NO. 2312, VOL. 92] 
or radiation. 
Are we, then, 
drifting back to a 
corpuscular emis- 
sion theory of 
light, destined to 
replace the now 
generally accepted 
wave theory? 
Such a’ return to 
older views: would 
not be. altogether 
without precedent. 
History. has wit- 
nessed. similar 
fluctuations of 
view as > regards 
the shape. and 
motion of . the 
earth, and as re- 
- gards -the . struc- 
ture of electricity. 
And the triumphs 
of atomistic con- 
ceptions in. other 
fields, achieved 
with the aid of 
radioactivity and 
of Brownian 
motions, make the 
propaganda for a 
further extension 
of the atomistic principle easy. R. A. Millikan} 
maintains that the number of atoms and molecules 
in a given mass of matter may now be counted 
with as much certainty and precision as we can 
attain in counting the inhabitants of a city. With 
the characteristics of these inhabitants we can deal 
| by means of the science of statistics, and the 
| adherents of the new atomistic theory of radia- 
| to 
| tion would have us apply statistical methods 
an immense range of physical . inyestiga- 
tions. 
But the hypothesis of ‘‘ quanta” or irreducible 
and indivisible elements of energy is not merely 
| atomism gone mad, There are certain undeniable 
and undoubted facts which find their simplest 
1 Scrence, vol. xxxvii., p. 119, January 24, 1913. 
