Explosion of Hydrogen and Oxygen. 109 



On examination afterwards, it appeared that a large fragment 

 of the globe had been projected behind me, striking a shelf in 

 which it caused a large indentation, and a fissure of more than 

 two inches in length, and of nearly one in depth. One large piece 

 of copper was projected over the heads of some persons present out 

 of an open window several yards distant from the table. The 

 windows being open, but one pane of glass was broken ; but the 

 sound was heard in all the college buildings, and at a very consid- 

 erable distance beyond. 



The question now arises, how could this explosion have oc- 

 curred with an apparatus which had been subjectedto such ap- 

 parently thorough and severe tests ? I have carefully examined 

 the tube and every fragment of the apparatus, and recalled all the 

 circumstances and arrrangements, without being able to discover 

 any imperfection or assignable cause. I have made experiments 

 with the tube and bladders since the accident, and with the same 

 results as before the explosion : the tube is as perfect as ever, 

 and as incapable of transmitting explosion. 



That the stop cocks and evexy part of the globe were perfectly 

 tight, and allowed of no leakage by which a stream of the gases 

 might have come in contact with the flame at the jet, I cannot 

 but feel confident, as nothing of the kind was observable du- 

 ring the condensation or in the previous trials. The apparatus 

 was new and very faithfully made. 



It was found by Mr. Hemming, that when the gases contained 

 a portion of water mechanically suspended in them, the flame 

 would return through the tube proposed by Mr. Gurney, where 

 layers of wire gauze, &c. are employed, and even in its improved 

 forni, where layers of asbestos are interposed. But with the tube 

 filled with wires, exhibited before the British Association, it is 

 stated to have been impossible to produce explosion, even when 

 the gases were made to recede by withdrawing the pressure on 

 the bladder. In the present case no recession could have taken 

 place from diminution of pressure, as the compressed gases were 

 rushing out with great velocity. 



How far the compression of the gases may have aided the 

 combination of their bases, we are unable to say ; but from the 

 experiments of Biot, we knov/ that it must be made suddenly and 

 violently, for when gradually applied, as in the sinking of a mix- 

 ture of the gases to the depth of one hundred and fifty fathoms, 



