258 
Notices of Books. 
[April, 
author starts with the hypothesis of M. Faye, who, in opposition 
to Wilson, Herschel, and Arago, maintains that the mass of the 
sun is entirely gaseous, and that by the contraction of this mass 
is furnished the enormous amount of heat radiated into space. 
Reviewing the gradual cooling and condensation alike of stars 
and of planets, he brings us to the dawn of the geological life 
of our earth, which he describes in accordance with views 
generally accepted. The elevatory action of the central heat he 
considers as “ slow and constant.” In his views of areas of 
elevation he mentions Australia, as not merely now rising, but 
as having been covered by the sea at no very distant time. Yet 
it seems perfectly clear that at dates geologically not very 
remote Australia must have passed through a stage of subsi- 
dence, and that it extended eastwards as far as the great 
“ Barrier Reef,” and to have been almost, if not quite, connected 
with New Guinea to the northward, as has been shown by Mr. 
A. R. Wallace. 
In the next chapter, treating of the “ Fluid Envelope of the 
Earth,” he calculates that at the present rate of denudation the 
entire American continent must be levelled and buried in the 
sea in four million years, supposing no upheavals to intervene. 
The denudation of India proceeds at a rate at least three times 
more rapid. 
The author does not consider the atmosphere as permanent 
either in its mass or its composition. “ According to Ebel- 
mann (?), if the stratified rocks had contained 1 per cent, of 
protoxide of iron, this would have been sufficient to absorb all 
the oxygen of the air.” He maintains that the (free) nitrogen 
of the atmosphere is also diminishing in quantity. He thinks 
that nitrogen is “ taken out of the air by guano and other 
analogous deposits and, on the authority of D’Archiac, asserts 
that the nitrogen withdrawn from the atmosphere cannot un- 
assisted return to its source, and that we know of no natural 
agent for its restoration ! By “Swiss Saxony” (p. 310) Prof. 
Pilar probably means the district usually known as the Saxon 
Switzerland, or better as the Highlands of the Elbe, extending 
from the southern side of the Dresden district to the frontiers of 
Bohemia. Speaking of the fadt, recorded already by Pliny, that 
mineral spring water is unsuited for culinary purposes, the 
author tells us that “ Chemistry teaches us that selenitic waters 
hold in solution carbonate of lime, which combining with the 
legumin render these fruit unfit for alimentation.” We should 
rather suppose that selenitic waters must contain selenite, i.e ., 
sulphate of lime. 
The author’s remarks upon the fossil fauna and flora of the 
world and upon the origin of species cannot be considered 
remarkably happy. Speaking of coal, he says : — “ England, 
Belgium, France, Prussia, Silesia, Bohemia, Hungary, possess 
mines of more or less importance. Scandinavia, Russia, Greece, 
