C. M. Warren on Organic Elementary Analysis. 393 
. mixture. Having seen no indication that any other than gas- 
: eous bodies escaped the combustion tube in such a case, it oc- 
| curred to me that such an analysis might be saved by collectin 
the gas over mercury, and, at the close of the combustion, be- 
__ fore detaching the absorbing apparatus, conducting it a second 
___ time through the combustion tube.* As a matter of economy, 
So, in the saving of the excess of oxygen, when a considerable 
___-humber of analyses are to be made, this idea seemed to recom- 
mend itself; as the oxygen would, at the same time, become 
purified from any traces of combustible matter which might be 
present, and could then safely be collected as pure oxygen, and 
finally transferred to the oxygen gasometer. 
_ I therefore constructed for this purpose the apparatus which 
is represented in the background of the preceding figure as 
attached to the anterioreend of the absorption apparatus, At 
the close of the combustion, when only pure oxygen appears to 
enter the potash bulbs, the flow of oxygen is interrupted; the 
communication with that portion of the drying apparatus which 
is back of the short U tube, A, is closed at 6; and the tube B— 
__* As the time consumed in an experiment is so short, and the quantity of com- 
bustible as present, if any, so very small, and that mixed with a very large quan- 
tity of oxygen, it is not improbable that the gas might as well be collected over 
Water: as the quantity which could be absorbed by the water in so short a space of 
time would probably be inappreciable. 
Aw. Jour. $ct.—Seconp Serres, Vou. XXXVIII, No. 114.—Nov., 1864. 
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