1864. | Metallurgy. 529 
This confession shows the limited capacity of our language—the poverty 
of our knowledge—the uncertainty of our scientific definitions—and 
of the nomenclature of science when it advances—or rather attempts to 
advance—from mere details to enlarged generalities, : 
Naturally following the subject of Fuel, the Fire-clays and Cruci- 
bles come under notice, together with Sands, Sandstones, and all the 
natural refractory Minerals employed in the construction of Furnaces, 
and as the means of exposing the Ores to the action of intense heat. 
This section cannot but be of great value to the practical man. Not 
only have we the results of the labours of our best Chemists and 
Metallurgists given in concise and clear terms, but we have a con- 
siderable amount of original research communicating much that is 
important. ; 
The Metallurgy of Copper has the first attention, and that of Zine 
follows. There are few metallurgical processes which require so large 
an amount of chemical knowledge as Copper Smelting. Dr. Percy has 
carefully described every stage in the process, and, at the same tine, 
explained the chemical changes which mark each stage. Nearly every 
condition of the furnace products in their passage from the ore to fine 
copper, has been submitted to the most searching examination in the 
author’s laboratory. There is one feature in connection with this 
research, and indeed with all the original investigations included in 
these volumes, which must be recorded with unqualified praise. In no 
case has Dr. Percy avoided giving his own assistants the full merits 
due to their labours. In some instances indeed we feel that he may 
have overstated the claims of those who have worked merely under his 
guidance. 
The history of Copper Smelting in Great Britain has evidently been 
a favourite subject of inquiry. It is therefore very complete. Not 
only have we full details of all the processes employed in this country 
—with drawings of the furnaces, &c., to scale, but we have accounts of 
Copper Smelting in Sikkim, Himalya, and other parts of India, in 
Japan, Sweden, Prussian Saxony, and Russia. It is quite impossible 
to do more than thus hastily notice these valuable contributions to 
applied science, which must be studied in the work itself by all who 
are desirous of obtaining accurate knowledge on the subject. 
The History of Zine Smelting is touched on, but it is not so satis- 
factorily given as that of Copper. Indeed the, in every way, interest- 
ing story of this Metallurgy in our own island is dismissed in a few 
lines. This is to be regretted, since the mining and smelting of 
Calamine—especially that which was raised in the Mendip Hills— 
was, in the time of Elizabeth, so important as to give rise to Acts of 
Parliament directed to prevent the Exportation of Zinc, mainly to 
compel “‘ Copper to be brought in for the manufacture of Gun-metal, 
Bell-metal, Schrof-metal, Latten,” &c., &e. Dr. Perey quotes much of 
the matter collected by Dr. Watson and Beckman, who dealt mainly 
with the ancient use of Zine, and but little of interest besides. 
The second volume of 934 pages is devoted to Iron and Steel. This 
is, without doubt, the most important division of Dr. Percy’s labours, 
He has departed from the plan pursued by him in treating of Copper 
