( 252 ) (April, 
NOTICES \OF) BOOKS: 
The Aerial World: A Popular Account of the Phenomena and 
Life of the Atmosphere. By G. Hartwic, M. & P.D. London: 
Longmans, Green, and Co. 1874. 
In this work we find a complete chemical and physical history 
of the atmosphere; the facts of all the sciences are brought 
forward to elucidate the subject: the physical properties of the 
atmosphere, sound and echoes, light in connection with the 
colours of the sky, heat in connection with the temperature of 
the air, winds, &c., electricity in connection with thunderstorms, 
St. Elmo’s fires, and electrical meteors; of each and all of these 
we have a full description. 
The first chapter treats of the weight and pressure of the air. 
In regard to the effect of rarefied air on the system,the author 
remarks that it is scarcely likely that any one will in future be 
foolhardy enough to endeavour to ascend above six miles, seeing 
how nearly Messrs. Coxwell and Glaisher lost their lives at the time 
of their famous balloon ascent. It has, however been suggested, 
that people who are in the habit of living in rarefied air—as the 
inhabitants of Quito and Potosi—might be able to reach a greater 
altitude than those who live at or near the level of the sea; and 
this experiment, which has never been tried, is certainly worth 
trying. In the course of a few generations of life, at high alti- 
tude, it is by no means improbable that the system might adapt 
itself to the surrounding circumstances, and that an extension of 
this rarefaction might be borne without difficulty. 
The second chapter treats of the chemical composition of the 
~ atmosphere, and the various gases which compose it are de- 
scribed. In speaking of ozone, the author quotes the ‘‘Odyssey” 
to show that the peculiar sulphurous smell which accompanies 
manifestations of electricity has been known from the time of 
Homer. He omits, however, that extremely interesting philo- 
logical fact, that the Greek for sulphur, @e0», was derived from 
this cause. Zeus manifested himself by thunderbolts; the 
sulphurous smell accompanied such manifestations; hence, 
clearly sulphur, in some way or other, appertains to the gods; 
hence it is assumed that it was called @sov (@oc); and we 
have the echo of the old Greek word in some of our more com- 
plex sulphur acids—trithionic, tetrathionic, pentathionic. In 
the third chapter we are introduced to the science of Acoustics, 
and come again to the mighty Zeus, in whose forest of Dodona 
the rustling of the oak leaves was believed to be the voice of the 
god himself. It is thus that the author blends mythology and 
history with the more sober facts of science. The fifth chapter 
