Mr. Grove on the Decomposition of Water by Heat, 93 



absorbed by the oil ; I have, however, always found the pro-- 

 portion of oxygen to decrease as the boiling was continued. 

 It may be vvorth noticing, as having bad some influence on 

 my mind, that many months ago, when considering the expe- 

 riments of Henry and Donny on the cohesion of water, I 

 mentioned to Mr. Gassiot, and also to Mr. Bingham my 

 assistant (to whose assiduity I am much indebted), that I was 

 inclined to think if water could be absolutely deprived of air, 

 it would be decomposed by heat, a result which I have now 

 attained by a totally different series of inductions. It is a cir- 

 cumstance worthy of remark, that I find the greater part of 

 the air to be expelled at a comparatively low temperature, and 

 when the water has come in contact with the platinum, while 

 the decomposition all takes place when the platinum is sur-p 

 rounded by an atmosphere of steam, if steam it may be called, 

 for the state of this atmosphere at the first immersion of the 

 platinum is at present very mysterious. 



I think I may now safely regard it as proved, that platinum 

 intensely ignited will decompose water, and several considera- 

 tions press on the mind in reflecting on this novel phaeno- 

 menon. 



First of all, to those who are attached to the cui bono argu- 

 ment, and estimate physical science in proportion only to its 

 practical applications, I would say that these experiments 

 afford some promise of our being, at no distant pei'iod, able 

 to produce mixed gases for purposes of illumination, &c. by 

 simply boiling water and passing it through highly ignited 

 platinum tubes, or by other methods which may be devised; 

 we in fact by this means, as it were, boil water into gas, and 

 there appears theoretically no more simple way of producing 

 chemical decomposition. 



To pass however to more important considerations: the 

 spheroidal state, which has lately attracted the attention of 

 philosophers, appears to be closely connected with these re- 

 sults, and is rendered more deeply interesting. The last 

 experiment but two which I have mentioned, shows that the 

 spheroidal state is intermediate between ordinary ebullition 

 and the decomposing ebullition ; it is probably therefore a 

 state of polar tension, coordinate in some respects with that 

 which takes place in the cell of a voltaic combination before 

 decomposition, or when the power employed not being of suf" 

 ficient intensity to produce actual decomposition, the state 

 commonly called polarization of the electrodes, obtains. The 

 phajnomenon brings out also a new relation between heat, 

 electricity, and chemical affinity; nitherto many electrical 

 phpenomena could be produced by heat and chemigal action, 



