so Mr. Grove 07i the Decomposition of Water hy Heat. 



wire is necessary, the sealing is more troublesome, and the 

 size of the bulb is much more difficult to adapt to the produc- 

 tion of steam in exactly the requi- Fig. 6. 

 site quantity ; the straight wire 

 being more suddenly extinguish- 

 ed and more easily fused : with 

 careful manipulation however it 

 succeeds equally well with the 

 former experiment. 



I might add other experiments 

 and arguments, but I believe when 

 the remainder of this paper has been read, that the above will 

 be thought scarcely necessary. 



I now directed all my efforts to produce the effects by heat 

 alone without the battery. I will mention a few of my unsuc- 

 cessful attempts, as it will save trouble to future experimenters. 

 I sealed a platinum wire into the extremity of a curved tube, 

 filled the latter with water, and applied a strong heat by the 

 blowpipe to the projecting end of the wire, hoping that the 

 conducting power of the platinum, although inferior to that of 

 most other metals, was sufficiently superior to that of glass to 

 enable me to ignite the portion of the wire within the tube, 

 and thus surround it with an atmosphere of steam ; the water 

 however all boiled off from the glass ; nor could I succeed in 

 igniting the platinum by heat from without. A similar failure 

 occurred when, on account of its superior conducting power, 

 a gold wire was substituted for that of platinum. 



I sealed spongy platinum and bundles of platinum wire into 

 the ends of Bohemian glass tubes, closing the glass over them, 

 and then filling the tubes with water and heating the whole 

 extremity; but the water boiled off" from the glass, and the 

 platinum could not be made to attain a full incandescence. 



After many similar trials I returned to the battery, and 

 sought to apply it in a manner in which electrolysis could not 

 possibly take place. I had hoped, as I have above stated, to 

 obtain a residual decomposition of water by masking or dilu- 

 ting the gases by a neutral substance. I therefore tried the 

 following experiment: a tube Fig. 7. 



similar to fig. 1 was filled with 

 water which had been carefully 

 freed from air by long boiling 

 and the air-pump ; it was then 

 inverted in a vessel of the same 

 water, and a spirit-lamp applied 

 to its closed extremity, until the 

 upper half was filled with va- 



