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 indepth. 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- 
cured with an apparatus which had been subjected to such ap- 
parently thorough and severe tests? I have carefully examined 
the tube and every fragment of the apparatus, and recalled all the 
citeumstances 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 
tesults as before the explosion: the tube is as perfect as ever, 
and as incapable of transmitting explosion. 
That the stop cocks and every part of the globe were perfectly 
ight, 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- 
ting 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 
* 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 
orm, 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 
‘ushing 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 
°Xperiments of Biot, we know that it must be made suddenly and 
Violent] 
t 
Y, for when gradually applied, as in the sinking of a mix- 
me of the gases to the depth of one hundred and fifty fathoms, 
