348 On the Combustion of Hydrogen in Water. 



gas in combustion with oxygen, will have its temperature 

 gapidly elevated. This was the fact ; the thermometer 

 rose, in a very short time, in a common half pint tumbler 

 filled with water, say from 50° or 60°, the temperature pre- 

 vailing at the time, to 170° and upwards. 



The reason why the temperature of 212° was not reach- 

 ed, was this. For the purpose of enabling myself to in- 

 troduce this gaseous flame, into very narrow recesses, I had 

 affixed to the orifice of the blowpipe beforementioned, a 

 silver tube, about an inch or an inch and a half long; which 

 conveyed the gases, m a mixed state, to their orifice of ig- 

 nition. The diameter of the bore of the tube might be, 

 perhaps, one twentieth of an inch. You are aware, then, 

 under these circumstances, that the flame might occasion- 

 ally recede, into the interior of the tube, to the place of 

 their conjunction. This I found very frequently to occur in 

 the water; but very seldom in the air. In fact, it often re- 

 quired care to introduce the flame, slowly and deliberately, 

 into the water, in order to avoid recession, at its first en- 

 trance. The length of time for which the recession could 

 be avoided, or rather was avoided, even under favourable 

 circumstances, was so short, that I did not attempt any ex- 

 periment, for the purpose of obtaining specific results. 



You will imagine, possibly, that with a heat so energetic 

 as the gases in question are known to produce, the water, 

 especially so small a quantity as half a pint, ought to be ex- 

 pected to boil very soon. But, it should be recollected, 

 that the flame was introduced, commonly, very carefully, 

 and to the depth only of about an inch or so. Little vertic- 

 al communication of hfat would take place ; the lateral 

 communication, would probably be still less — more espe- 

 cially when we consider that the water in immediate con- 

 tact with the flame might be expected to be instantaneously 

 converted into steam and ascend to the surface, which was, 

 to all appearance, the fact. Indeed I was not a little sur- 

 prised to find that, with the same blow-pipe, and under the 

 same circumstances, water was much more heated by the 

 application of it, for a given time to the exterior of a tin 

 vessel than when the same flame was submersed in an equal 

 quantity of the same fluid. 



To obviate the evil of the recession of the flame, tubes of 

 a fine capillary bore, so small as to prevent recession, are 



