ix SCIENTIFIC MOTIVE 253 



of great value in cases of diabetes and other disorders 

 in which ordinary cane-sugar has to be avoided in a 

 patient's diet, was discovered in 1879 while an investiga- 

 tion was being carried on in Prof. Ira Kemsen's laboratory 

 that seemed as little likely to lead to practical results 

 as any that could well be imagined. 



Any practical man would unhesitatingly have condemned 

 the work as being utterly useless, and I may add that some did 

 condemn it. There was no hope, no thought entertained by us 

 that anything practical would come of it. But lo ! one day it 

 appeared that one of the substances discovered in the course 

 of the investigation is the sweetest thing on earth ; and then it 

 was shown that it can be taken into the system without injury ; 

 and finally that it can be manufactured at such a price as to 

 furnish sweetness at a cheaper rate than it is furnished by the 

 sugar cane or the beet. And soon a great demand for it was 

 created, and to-day it is manufactured in surprising quantities 

 and used extensively in all corners of the globe. Prof. Ira Remsen. 



Early in the nineteenth century Sir Humphry Davy 

 succeeded in decomposing caustic potash and caustic 

 soda by means of the electric current, and in obtaining 

 from them the metals potassium and sodium. The 

 experiment was made to settle a disputed question in 

 pure chemistry, but it was the starting-point of an 

 immense industry. At the present time, the only 

 process of commercial importance for making sodium 

 is that of electrolysis of caustic soda, all chemical 

 methods of manufacturing the metal being superseded 

 by it. Caustic soda itself, together with chlorine for 

 bleaching purposes, is obtained from common salt by 

 electrolytic methods on a large scale ; and its manu- 

 facture is an important industry. 



In 1833, Faraday obtained the metal magnesium 

 from a compound of the element by means of electro- 

 lysis ; and now the magnesium ribbon and powder 



