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composed by bringing it in contact with any 

 heated combustible substance, as ir^ making it 

 pass through a gun-barrel heated red-hot, when 

 the oxygen will be abstracted by the combus- 

 tible or oxidizable matter (the iron), and the 

 hydrogen comes off in the form of hydrogen 

 gas. Water is indeed formed wherever there is 

 a combustion of any matter containing hydro- 

 gen, as may be seen by fixing a glass receiver, 

 of a globular form, over one of Argand's lamps, 

 which in a little time will be found to contain 

 water. Thus, like most other matters on the sur- 

 face of the globe, water is continually changing 

 its nature. 



While water was considered as a pure ele- 

 mentary substance, some were of opinion that 

 the sea was continually diminishing, so that the 

 parts which are now covered with it would in 

 time be dry land. A number of proofs have 

 been offered in support of this opinion; but 

 those in the Swedish Memoirs, concerning the 

 Baltic Sea, are most curious. We are told that 

 a number of rocks, well known, have, in the 

 memory of many persons now living, become 

 more prominent above the surface of the sea. 

 Solid rocks are the best proof of any opinion of 

 this kind, for land might be washed away, or 

 have additions made to it; but a solid rock, 

 which is composed of materials not so liable to 

 decay, must necessarily show if the surface of 

 the sea is lower. 



