of the fixed Alkalis, 13 



much heat and noise, but no Itraiiuous appearance, and the 

 gas evolved when examined in the mercurial or water pneu- 

 matic apparatus is found to be pure hydrogen. 



When a globule of the basis of potash is placed upon ice 

 it instantly burns with a bright flame, and a deep hole is 

 made in the ice, which is found to contain a solution of 

 potash. 



The theory of the action of the basis of potash upon water 

 exposed to the atmosphere, though complicated changes 

 "occur, is far from being obscure. The phoenomena seem to 

 depend on the strong attractions'of the basis for oxygen and 

 of the potash formed for water. The heat, which arises 

 from two causes, decomposition and combination, is suffi- 

 ciently intense to produce the inflammation. Water is a bad 

 conductor of heat ; the globule swims exposed to air : a part 

 of it, there is the greatest reason to believe, is dissolved by 

 the heated nascent hydrogen; and this substance being ca- 

 pable of spontaneous inflammation, explodes, and commu- 

 nicates the effect of combustion to any of the basisthat may 

 be yet ujicombiued. 



When a globuje confined out of the contact of air is act- 

 ed upon by water, the theory of decomposition is very sim- 

 ple, the heat produced is rapidly carried off, so that there is 

 no ignition ; and a high temperature being requisite for the 

 solution of the basis in hydrogen, this combination probably 

 does not take place, or at least it can have a momentary ex- 

 istence only. 



The production of alkali in the decomposition of water by r 

 the basis of potash is demonstrated in a very simple and 

 satisfactory manner by dropping a globule of it upon moist- 

 ened paper tinged with turmeric. At the moment that the 

 globule comes into contact with the water, it burns, and 

 moves rapidly upon the paper, as if in search of moisture,^ 

 leaving behind it a deep red dish -brown trace, and actino- 

 upon the paper precisely as dry caustic potash. 



So strong is the attraction of the basis of potash for oxy- 

 gen, and so great the energy of its action upon water, that 

 it discovers and decomposes the small quantities of water 



contained 



