408 
POPULAR SCIENCE REVIEW. 
Copper-smelting and the extraction of copper from burnt pyrites by the 
wet method, are both well epitomized ; but the metallurgy of silver is not 
made to embrace some recent processes. The Pattinson kettles are shown 
with “ heaters,” which are now almost obsolete ; and no mention is made of 
Luce and Rozan’s steam process ; while the modifications of Park’s method 
for extracting silver from lead by the addition of metallic zinc are but briefly 
alluded to. These two systems have now, to a very large extent, superseded 
crystallization in pots and the removal of the crystals in perforated ladles. 
Mr. Claudet’s process, by which 150,000 ozs. of silver are annually recovered 
from copper liquors by the addition of a soluble iodide is, however, noticed. 
Dr. Paul’s book, although not perfect, is in many respects superior to 
the original work, since not only has the chemistry of Payen been amplified 
and modernized, but various manufacturing processes employed in Great 
Britain have been supplemented to the Continental methods, chiefly given in 
the French and German editions. Besides this, many valuable articles have 
been added on the chemistry of the metals, and on the metallurgical treat- 
ment of their ores. Although, in some few cases, valuable inventions have 
been lost sight of, on the whole the editor has done his work very carefully, 
and the result is a valuable contribution to the technical literature of the 
country. 
PHYSIOGRAPHY.* 
A FTER the abundant criticism to which the latest addition to scientific 
terminology, represented by the word Physiography, has been subjected, 
Mr. Skertchly does wisely in adopting a title which is explanatory of his 
purpose, and which to a certain extent serves as a definition of the object he 
proposes to accomplish. This definition is materially aided by the quotation 
on the title-page which affirms that 
All are but parts of one stupendous whole, 
and is supplemented by a statement in the introduction, to the effect that 
" This volume is in one sense a manual of Physical Geography, but it differs 
from other works in attempting to knit the phenomena of the globe into 
a coherent train of reasoning. Physical Geography is too often degraded 
into a sort of scientific curiosity shop, in which there is a vast collection of 
isolated facts respecting Astronomy, Geology, Physics, Biology, and what 
not, without the slightest attempt at grouping them, to show how inter- 
dependent they are upon one another.” 
The fact is, that of late years the tendency of Science, like the impreg- 
nated ovum, has been towards fissure and constant subdivision : universal 
or encyclopaedic knowledge has more than ever become a chimaera ; and it 
might with more force than formerly be argued against a philosopher of the 
Whewell school that “ Science was his forte, and Omniscience his foible.” 
Farseeing men, however, of Huxley’s type, have realized the fact that we 
* “ The Physical System of the Universe.” An outline of Physiography, 
by Sydney B. J. Skertchly, F.G.S. Cr. 8vo., London, 1878. Daldy, 
Isbister & Co. 
