550 Reviews— Jevons—On The Coal Question. 
pared with the first two, wuich sometimes make up 95 and 97 per 
cent. of the ooze ! 
We are much indebted to the authors of this interesting memoir 
for giving us, as it were, a new test, which the paleontologist may 
in many instances apply, to solve the question of the conditions of 
marine life in bygone ages of geologic time. 
JI.—TueE Coal QUESTION ; AN INQUIRY CONCERNING THE PROGRESS | 
OF THE NATION, AND THE PROBABLE EXHAUSTION OF OUR COAL 
Mines. By W. Srantey Jevons, M.A. Cambridge : Mac- 
millan, 1865. ; 
HIS book is not a rival but rather a fitting partner to Mr. Hull’s 
‘ Coal-fields of Great Britain.? Whilst Mr. Hull looks on Coal 
as a purely geological matter, Mr. Jevons views it as within the 
domains of statistical and political economy, taking Mr. Hull as his 
guide in geology (p. xii.). 
The truth of Mr. Jevons’s statement (p. x.) that ‘the writers who 
have hitherto discussed this question, being chiefly geologists, have 
. . treated it . . in a one-sided manner,’ may be doubted. Surely 
there cannot be a question any side of which is without a geologist 
to argue for it. Mr. Jevons, however, clearly does not mean by the 
above passage to cast a slight on geological enquiry; for he says (p. 
30) that ‘if the science of geology had no claims upon our attention 
it would repay all the labour spent upon it many times over, by 
showing where coal may reasonably be looked for.’ Perhaps, though 
the labour thus spent may be much greater than Mr. Jevons thinks, our 
author disagrees with former writers in thinking that ‘there is not 
the least danger of our reaching any fixed limit of deep mining, where 
physical impossibility begins’ (p. 40), and he points out a mistake 
of Mr. Hull’s in over-estimating the increase of temperature in des- 
cending further into the earth (p. 42), but he looks forward rather 
to ‘commercial impossibilities’ in the cost of sinking and working 
deep pits, and shows that the price of best Newcastle coal has more 
than doubled in less than 100 years. But, in an able pamphlet on 
the ‘ Fall of the Value of Gold’ (Stanford), Mr. Jevons has himself 
proved that there has been a rise in the prices of most things, and 
therefore the force of the above fact is somewhat lessened, although 
not enough to shake the conclusion that ‘when with the growth of 
our trade and the course of time our mines inevitably reach a depth 
of 3,000 or 4,000 feet, the increasing cost of fuel will be an incaleu- 
lable obstacle to our further progress’ (p. 67) ; for even now ‘deep 
mines are so deliberately opened . . . that the highest prices ob- 
tained are, taking all mining risks and charges into account, only an 
average equivalent for the capital invested ;’ moreover ‘these deep 
pits can only be undertaken at present in search of coal of the finest 
household quality’ (p. 66), Mr. Jevons combats the notion that by 
a more economical use of coal, through improvements in machinery, 
&c., the increase of consumption will be stopped or checked, and 
holds that ‘new modes of economy will lead to an increase of con- 
sumption, acccrding to a principle recognised in many parallel in- 
