144 
DETERMINATION OF NITROGEN. 
of an inch) in diameter. To the open extremity there is to 
be adjusted hermetically, by means of pierced cork, which 
need not be dried, an apparatus of the following form, 
containing; hydrochloric acid for the absorption of the am- 
monia. The form of this apparatus differs but little from the 
potassa apparatus of Liebig: this latter doubtless fulfils its 
object, absorption ; but its construction renders it difficult to 
wash completely, a necessary condition after each experiment. 
The form of apparatus which we have chosen answers well, 
without rendering the absorption less complete ; as the ab- 
sorption of ammonia by the acid is much more rapid than 
that of carbonic acid by potassa, it is useless, in the determina- 
tion of nitrogen, to multiply the points of contact of the gas 
and liquid, as is done so ingeniously in the potassa ap- 
paratus. 
The apparatus is filled by plunging the point in hydro- 
chloric acid of ordinary strength, (sp. gr. 1.13) and inspiring 
the air from d, until the liquid assumes the height indicated 
in the figure. 
We use, as the means of decomposing the organic matters 
containing nitrogen, for the purpose of oxidizing their carbon 
and hydrogen, a mixture of hydrate of potassa, or of soda 
with quick lime, in such proportions, that, still energetic in 
action, it will not fuse at a red heat, but only slightly aggluti- 
nate. This mixture offers at the same time the advantage of 
