106 Explosion of Hydrogen and Oxygen. 
in length, to increase the cooling surface ; and bladders, contain- 
ing hydrogen and oxygen gases in the proportions that compose 
water, were attached to the two extremities. The stop cocks 
being opened, the gases were forced from one bladder into the 
other several times through the leaden tubes and that of Hem- 
ming’s interposed, thus ensuring their mixture both in the blad- 
ders and tubes. The apparatus was now placed in the open alr, 
and an arrangement made which allowed me to explode one of 
the bladders and observe the effect without danger. 'The one 
bladder alone exploded. This experiment was repeated many 
times, shortening the leaden tubes each time, until they were el- 
tirely removed, and bladders were attached directly to the Hem- 
ming’s tube. One of them was then exploded, but the flame 
was arrested as completely as in the previous trials. 
Having repeated the experiment with the Safety Tube alone 
several times, and uniformly finding it impossible to explode both 
bladders, I now did not hesitate to hold the tube in my hand, and 
to apply a flame to one bladder ; this was repeated several times, 
and in no instance was explosion communicated from the one 
bladder to the other. Mr. Hemming is stated to have operated 
before the members of the British Association with the bladder 
under his arm; and Dr. Hare in his letter to Dr. Dalton,* states 
that he has ceupharred the mixed gases with safety, more than a0 
hundred times, allowing them to explode as far into the tube of 
efflux as where the contrivance in questiont was interposed, 
without explosion extending beyond it 
The safety of the tube having been so thoroughly tested with 
the bladders, I now substituted for one of them a strong globe 
12 inches in diameter, made of 22 oz. copper; this, as well as 
the bladder was filled with the mixed gases. The apparatus Was 
placed out of doors, and, with the necessary precautions as to per 
sonal safety, the mixture in the bladder was fired, but that in the 
copper globe did not explode. 'The same result always occulTe 
in repeating this, and in no trial could I cause the flame to trav- 
erse the Hemming’s tube. 
y next experiments were made without the bladder. A 
small jet, —— an orifice of about ,'; of an inch diametel, 
Ne si ihanaltemaeOe 
* Amer. ae Vol.- XxxuI, p, 196. put 
t Dr. Hare alludes to some improvement he has made in Hemming’s tube, ?? 
has not informed us in what it consists, 
