1864. ] Metallurgy. 527 
The ‘Metallurgy’ of Dr. Percy is published to mect a want 
which has long been felt, and which we rejoice to see, at last, ade- 
quately supplied. The two volumes which are completed (we think 
it wise to include both in our notice, although Vol. I. was published 
in 1861) embrace the most important Metallurgies, and they really 
leave but little to be desired. The author is peculiarly fitted by his 
education, and his opportunities, for the production of a work which 
must be equally acceptable to the manufacturer and the man of 
science. 
To place an Ore of Lead—or Copper—or Iron in a fire, and by 
the intensity of heat to run out a fluid metal, is certainly a simple 
matter. But when we remember that nearly all ores are of a very 
compound nature; that the chemical affinities in action are of the 
most powerful kind; and that the metallurgist has so to direct his 
skilled labour, that a metal, as nearly pure as possible, may be the 
result, we shall be convinced that a considerable amount of scientific 
knowledge is required. 
“ As the word science in relation toa manufacturing art is often vaguely 
used, it may be well to give the following illustration of its meaning :— 
When an ore of copper, consisting essentially of copper, iron, sulphur, and 
Silica, is subjected to a series of processes, such as heating with access of 
air under special conditions, melting, &c., copper is separated in the metallic 
state. ‘The sum of these processes is termed the smelting of copper. In 
this operation of smelting, certain chemical changes take place : the sulphur 
combines with the oxygen of the air, and is evolved chiefly as sulphurous 
acid ; the iron is similarly converted into oxide, which combines with the 
Silica present to form a fusible compound or slag. There are thus several 
facts’ which are proved on chemical evideuce. These facts, when sys- 
tematically arranged, may be said to constitute the scientific knowledge of 
copper smelting : and that knowledge implies necessarily a knowledge of 
the chemical relations of copper, iron, sulphur, oxyzen, and silica to each 
other. . . . The man who conducts the process of copper-smelting in 
ignorance of these facts, has simply an empirical, in contradistinction to a 
scientific, knowledge of the art.” * 
Dr. Perey’s aim has been to give, in this work, clear technical de- 
scriptions of each process, and to explain by the light of science, the 
philosophy, if the word may be allowed, of every step. To do this, close 
and laborious study, at the furnace mouth, has been necessary, and 
this has been followed by a searching analysis of the products, in the 
quiet of a well-regulated laboratory. 
This work is intended to convey the largest possible amount of 
information relating to the production of the Metals Nature gives 
us but two or three in a pure or native state, and, as it is designed 
with all things, the power of mind is necessary to mould them to a 
condition in which they become useful. Therefore, this work, very 
4. ‘Papers on Iron and Steel, Practical and Experimental.’ By David 
Mushet. John Weale, London. 
5. ‘The Iron Manufacture of Great Britain, Theoretically and Practically 
Considered.’ By William Truran, C.E. E. & F. N. Spon, London. 
6. ‘An Elementary Treatise on Iron Manufacture.’ By Samuel Baldwyn 
Rogers. Simpkin, Marshall, & Co., London. 
* «Metallurgy :’ Introduction. 
