i88 CLASSICS OF MODERN SCIENCE 

 in glass tubes furnished with electrified platina wires, the new sub- 

 stances were generated at the negative surfaces ; the gas given out at 

 the other surface proved by the most delicate examination to be pure 

 oxygen ; and unless an excess of water was present, no gas was evolved 

 from the negative surface. 



In the synthetical experiments, a perfect coincidence likewise will 

 be found. 



I mentioned that the metallic lustre of the substance from potash 

 immediately became destroyed in the atmosphere, and that a white 

 crust formed upon it. This crust I soon found to be pure potash, 

 which immediately deliquesced, and new quantities were formed, 

 which in their turn attracted moisture from the atmosphere till the 

 whole globule disappeared, and assumed the form of a saturated solu- 

 tion of potash. 



When globules were placed in appropriate tubes containing com- 

 mon air or oxygen gas confined by mercury, an absorption of oxygen 

 took place ; a crust of alkali instantly formed upon the globule ; but 

 from the want of moisture for its solution, the process stopped, the 

 interior being defended from the action of the gas. 



With the substance from soda, the appearances and eflfects were 

 analogous. 



When the substances were strongly heated, confined in given pro- 

 portions of oxygen, a rapid combustion with a brilliant white flame 

 was produced, and the metallic globules were found converted into 

 a white and solid mass, which in the case of the substance from potash 

 was found to be potash, and in the case of that from soda, soda. 



Oxygen gas was absorbed in this operation, and nothing emitted 

 which affected the purity of the residual air. 



The alkalies produced were apparently dry, or at least contained 

 no more moisture than might well be conceived to exist in the oxygen 

 gas absorbed; and their weights considerably exceeded those of the 

 combustible matters consumed. 



The processes on which these conclusions are founded will be fully 

 described hereafter, when the minute details which are necessary will 

 be explained, and the proportions of oxygen, and of the respective 

 inflammable substances which enter into union to form the fixed 

 alkalies, will be given. 



It appears, then, that in these facts there is the same evidence for 



