554 KANSAS CITY REVIEW OF SCIENCE. 
efforts have been made to break the strength of the argument upon which it rests. 
But it must be admitted that these efforts have been, so far, futile, and that it is 
impossible to escape, with our present knowledge of physical laws, from the con- 
clusion above enunciated It is undeniable that every heated substance or sphere 
is losing its heat, that every cold substance or sphere is receiving heat from hot- 
ter sources and that all material activity is a result ofthis interchange. This pro- 
cess Can have but one result, judging from the present standpoint of science. 
Heat equilibration and material stagnation must ensue. General rest and death 
must succeed the energy and activity which now give vitality to the universe. 
If, however, we can, as yet, adduce no physical principle to annul the con- 
clusions of this celebrated hypothesis, it cannot be declared that no such prin- 
ciple exists, since it is quite possible that we are ignorant of, or mistaken in, 
regard to, many of the governing laws of nature. Facts always have the preced- 
■■ence of theories, and there are certain facts which seem irreconcilable with the 
hypothesis referred to. As it has never yet been considered, so far as we are 
aware, in the light of these facts, we propose to adduce them here, as an illustra- 
tive argument against its conclusions, where all logical arguments have failed. 
As to the primary condition of the universe two theories exist. It either 
began its existence at some definite period, in response to a creative fiat ; or it 
has existed from eternity, and has during infinite time been subject to the same 
laws which now control it. If the latter view is accepted the stagnation hypothe- 
sis at once goes by the board. A clock whose motion is not perpetual, and 
which began to run down at an infinite period in the past, must have come to 
rest infinite ages ago. 
If, however, the universe commenced its existence at some finite period in 
the past, its present activity is perfectly compatible with a movement towards 
final stagnation. We cannot deduce from the conditions of the stellar universe 
which hypothesis of "the beginning" is the correct one. But these conditions 
may lead us to some conclusion as to the probable course of stellar evolution. 
We know that all stellar evolution has been a process of material condensa- 
tion and integration. Diffused matter has gathered into nebular masses. These 
have condensed into solar nebulae, and the latter into suns with attendant planets. 
Many of the planets have cooled off and solidified superficially, and in some 
cases perhaps completely. Suns have also cooled, and in many cases may have 
lost their luminousness. 
The visible universe presents instances of this whole range of gradations. 
There are distinguishable in the skies stellar masses of many degrees of lumin- 
osity. Some indicate in the spectroscope an intensely heated condition. Others 
appear much less heated. Some have grown comparatively cool. Others, as 
the companion of Sirius, are but faintly luminous. Still others, as the companion 
of Procyon, have lost all visible light-giving powers. That there are dark suns 
which have cooled far below the luminous stage cannot be proved, but is quite 
within the range of probability. 
On the other hand numerous stellar bodies exist which have not yet attained 
