254 DISCOVERY CH. 



used for flash-light and other purposes are almost 

 entirely made by the same method. But the most 

 important application of electricity to industrial chemis- 

 try is the electrolytic production of that most useful 

 metal, aluminium, which is destined to compete with 

 iron and steel in its importance. Aluminium is now 

 manufactured exclusively by electrolysis of a fused 

 mineral containing it, though a few years ago it was 

 obtained wholly by purely chemical methods. Unlike 

 the examples already mentioned, the actual process of 

 producing aluminium by electrolysis was not derived 

 directly from a scientific laboratory, yet it and all other 

 electrolytic methods would never have come into being 

 but for the discovery by men of science of the chemical 

 effects of the electric current. 



Industrial chemistry has, in fact, been revolutionised 

 by the application of electrical methods ; and the 

 foundation of the new branch was laid chiefly by the 

 genius and research of Davy and Faraday, being practi- 

 cally based on the laws enunciated by the latter. 

 Metals, such as copper and iron, are obtained in the 

 highest state of purity by electrolysis ; in the United 

 States alone, more than twenty million pounds' worth 

 of copper are electrically refined every year. Silver, 

 gold and lead are also refined on a large scale by 

 electrical methods. Electro-plating with gold, silver, 

 nickel and other metals ; electrotyping, which is used 

 in every printing works to obtain copies of type and 

 engravers' blocks ; the electrolytic reproduction of 

 medals and similar articles, and a hundred other com- 

 mercial uses have been found for methods which when 

 first discovered were considered to be of interest only 

 to the world of science. It was the remembrance of 

 such facts as these as to the influence of scientific work 



