168 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1911. 
and costly of chemical reactions, but it has in many cases supplanted 
them by quick, simple, and direct.methods; it has even, in many 
cases, developed new reactions and produced new materials which 
are not otherwise capable of being made. A few examples will 
illustrate these points: Caustic soda and bleaching powder are made 
from common salt by a series of operations, but the electrical method 
does this neatly and cheaply in practically one operation; lime and 
carbon do not react by ordinary chemical processes, but in the electric 
furnace they react at once to form the valuable and familiar calcium 
carbide; carbon stays carbon except when the intense heat of the elec- 
tric furnace converts it into artificial graphite. The list of such opera- 
tions is a long one, and it may be said that the chemist has become a 
much more highly efficient and accomplished chemist since he became 
an electrochemist, and he is becoming more of an electrochemist daily. 
Electrometallurgy applies electric energy to facilitating the solution 
of the problems confronting the metallurgist. Its birthis but recent, 
yet it has rendered invaluable service; it has made easy some of the 
most difficult extractions, has produced several of the metals at a 
small fraction of their former cost, and has put at our disposal in com- 
mercial quantities and at practicable prices metals which were formerly 
unknown or else mere chemical curiosities. It has, further, refined 
many metals to a degree of purity not previously known. The metal- 
lurgist is rapidly appreciating the possibilities of electrometallurgical 
methods and they already form a considerable proportion of present 
metallurgical practice. 
Applied electrochemistry, covering in general all of the field 
just described, “is therefore an important part of chemistry and 
metallurgy, and is rapidly increasing in importance. It is a new 
art, people are really only beginning to understand its principles 
and to appreciate its possibilities; it is an art pursued by the most 
energetic and enterprising chemists, with the assistance of the 
most skilled electricians. Some of its most prominent exponents 
are electrical engineers who have been attracted by the vast possi- 
bilities opened up by these applications of electricity. The chem- 
ists have worked with electricity like children with a new toy, or a 
boy with a new machine; they have had the novel experience of 
seeing what wonders their newly applied agency could accomplish, 
and it is no exaggeration to say that they have astonished the 
world—and themselves. 
THE AGENTS OF ELECTROCHEMISTRY. 
The operating agent in electrochemistry is, of course, electric 
energy, which may be used in three classes of apparatus, viz: 
I. Electrolytic apparatus. 
If. Electric arcs and discharges in gases. 
Ill. Electric furnaces. 
