1908] on Dav if s Discovery of the 3Ietals of the Allcalis. 7 



Few discoveries of like magnitude have been made and perfected 

 in so short a time, and few memoirs have been more momentous 

 in result than that which, put together in a few hours, gave the 

 results of that discovery to the world. 



The whole work was done under conditions of great mental ex- 

 citement. His cousin, Edmund Davy, who at the time acted as 

 his assistant, relates that when he saw the minute globules of the 

 quicksilver-like metal burst through the crust of potash and take 

 fire, his joy knew no bounds ; he actually danced about the room 

 in ecstasy, and it was some time before he was sufficiently composed 

 to continue his experiments. 



The rapidity with which he accumulated results, after this first 

 feeling of delirious delight had passed, was extraordinary, and he had 

 obtained most of the leading facts concerning the physics and chemistry 

 of the new substances before the middle of November. 



He began his lecture with a f ehcitous reference to the concluding 

 remarks of one of the previous year, namely : " That the new methods 

 of investigation promised to lead to a more intimate knowledge than 

 had hitherto been obtained concerning the true elements of bodies. 

 This conjecture, then sanctioned only by strong analogies, I am now 

 happy to be able to support by some conclusive facts." 



In the first attempts he made to decompose the fixed alkalis he 

 acted upon concentrated aqueous solutions of potash and soda with 

 the highest electrical power he could then command at the Royal 

 Institution, viz., from voltaic batteries containing 2:> plates of copper 

 and zinc of 12 inches square, 100 plates of 6 inches, and 150 of 4 

 inches, charged with solutions of alum and nitric acid ; but although 

 there was high intensity of action, nothing but hydrogen and oxygen 

 was disengaged. He next tried potash in igneous fusion, and here 

 the results were more encouraging : there were obvious and striking 

 signs of decomposition ; combustible matter was produced, accom- 

 panied with flame and a most intense light. He had observed 

 that, although potash, when dry, is a non-conductor, it readily con- 

 ducts when it becomes damp by exposure to air, and in this state 

 " fuses and decomposes by strong electrical powers." 



Let me state in his own words, for the words are classical, what 

 followed : — 



" A small piece of pure potash, which had been exposed for a few 

 seconds to the atmosphere, so as to give conductive power to the sur- 

 face, was placed upon an insulated disc of platina, connected with the 

 negative side of the battery of the power of 250 of 6 and 4 [that is 

 100 plates of 6 inches square and 150 plates of 4 inches square] in a 

 state of intense activity ; and a platina wire communicating with the 

 positive side was l)rought in contact with the upper surface of the 

 alkali .... Underthese circumstances a vivid action was soon observed 

 to take place. The potash began to fuse at both its points of electriza- 

 tion. There was a violent effervescence at the upper surface ; at the 



