104. =~—- Explosion of Hydrogen and Oxygen. 
: Arr. X.—E zplosion of Hydrogen and Oxygen, with remarks 
on Hemming’s Safety Tube; by Prof. J. W. Wessrer of 
Harvard University.. 
Te occurrence of several explosions of the compound blow- 
pipe of Dr. Hare, in the hands of experienced chemists, is well 
known ; and the student can take up none of the modern chem- 
ical books without being made aware of the danger of using al 
imperfect or ill contrived form of the apparatus. In the use of 
two separate reservoirs for the gases, and the double concentric 
jet, it is impossible that explosion can occur. But it has, as those 
accustomed to use this splendid instrument* are well aware, beet 
modified in various ways, with the desire to render it more porta- 
ble, safe or convenient. The repetition of the early experiments 
of Dr. Hare and Prof. Silliman, by the late Dr. Clarke, of Cam- 
bridge, (Eng.) and his disregard of the claims of these gentlemen, 
are also well known; but it is somewhat singular, that so many 
| of the British chemical writers should still incline to give the 
____ eredit of these brilliant results to him who but repeated what had 
been long before accomplished in this country. As every chemist 
must deem the compound blow-pipe, in some form, an essential 
portion of his apparatus, and as it has even become one of the 
constituent parts of the cheap, and too often imperfect, ‘sets of 
apparatus,” manufactured in all parts of the country, for the usé 
of schools of all grades, not unfrequently to be used by begit 
ners or inexperienced persons, it is highly important that every 
one should be aware of the danger of operating with the single 
vessel as a reservoir of the mixed gases. 'The convenience ° 
transportation, and the small space it occupies, are great tempta 
tions to make use of the single vessel and compressed gases, a8 1 
the form first employed in England in the blow-pipe of Mr. 
Brooke. The tremendous explosions which took place with this 
instrument in the hands of Dr. Clarke, and of several others, t 
defences erected by the operators for personal protection, and the 
modifications in the jets, ad infinitum, with which the philoso- 
phical journals teemed, are too well known to be described. But 
PS Res ei a a So ees 
been 
with 
* For this invention our distinguished countryman, Dr. Hare, has recently 
most deservedly honored by the American Academy of Arts and Sciences 
the Rumford medals, 
———— sae aie ni siee a aii eneeecnaeens eae 
