Comparison of the Blowpipes of Hare and Brook. 87 
CHEMISTRY, PHYSICS, MECHANICS, AND THE ARTS. 
——— 
Art. XIII.—Upon the cates 8 of! various per bodies 
by H lowpipe. 
(Translated from ee Annales de Chimie et de At ead of Panis, for July, 
820—Editors Gay Lussac and Arago 
Tur blowpipe of Hare was described in the Annals of 
Chemistry, pipe, 45, p. 113.) It is. eee plied by two 
streams, one SA hydrogen and the other of ox ss Oath which do 
not mix till ‘moment of their combust and conse- 
quently are attended by no kind of danger. “This b 
is in this respect far preferable to that of Newman, or th- 
er of Brook, who appears to have been the first in inventor, 
and it is notinferior to it, or only in avery slight* degree, in in- 
tensity of heat. e can besides supply it with hydrogen 
gas and oxigen gas, compressed each in its own reservoir ; 
but, if we were to judge of it by the effects produced by this 
instrument, and by that of Brook, meio is but little advan- 
tage in having recourse to this means. _ 
The « simplest mode of es Om Hare’s slow pipes ina 
laboratory, would be, by taking two cylindrical bell glasses, 
furnished with stop cocks, the horizontal sections of which 
(the glasses) should be such, that oe one should present a 
surface double to that of the other: they are to be fixed in 
the pneumatic cistern, the largest to contain oxigen and the 
smallest hydrogen. From each of the bell glasses should 
joo a pe oes eee Semele # ina sg ated pred 
by 0 opening the stop cocks, always in the : fas 
water, whie i is aie’ best sap to prodin Ag maximuns 
of heat. , oe ee 
Whether it is stabs ¥en i in the slightest seine site seen sia the 
‘ogee connie of results, made Adit J bogie our last! Soe 
