Determination of Nitrogen in Organic Compounds. 253 
Arr. VI._—A New Method of determining the quantity of Nitro- 
_ genin Organic Compounds ; by Drs. Varrentrapp and Witt. 
# bi » ‘Translated from the original in the Annalen der Chemie und 
en Pharmacie, by J. Lawrence Surrn, M. D. of Charleston, S.C. 
_. Messrs, Editors—In this letter I send you a translation of such 
parts of the original article of Drs. V. and W. as may enable one 
to thoroughly understand this valuable addition to what is already 
known upon the subject of organic analyses; neither the first nor 
the latter parts are here taken notice of, as the one is merely a 
detached account of the various processes that have been pre- 
viously employed to estimate the quantity of nitrogen in organic 
compounds, and the other, the mention of some analyses made 
With the view of comparison. 
“'Phis method has for its basis the peculiar action of the hy- 
drated fixed alkalies, upon organic substances containing nitrogen, 
when subjected to a high temperature. It consists in the separa- 
tion of nitrogen in the form of ammonia, and estimating the lat- 
ter, either under the form of the muriate of ging and ammo- 
nia, or from metallic platinum.” 
“Tf one melts an organic substance free foie nitrogen, together 
With the hydrate of potash, the water of the potash becomes de- 
composed, (as Gay Lussac has shown,) its oxygen combines 
With the carbon and hydrogen of the organic matter, and its 
hydrogen passes off in the form of gas. 
For a perfect result of the above nature a high temperature is 
required, as well as a considerable excess of potas 
‘i “When on the contrary, the organic substance contains nitro- 
gen, the free hydrogen combines with it and forms ammonia. 
Since the observation of this fact, the only use that it has been 
put to, has been that of ascertaining the presence of nitrogen in 
an organic compound.” 
The first and chief difficulty that presented itself to Drs. V. 
and W. in making use of this method to estimate the quantity 
of nitrogen, was that when a substance was very rich in that 
element, the whole of it would not be converted into ammo- 
hia, ‘en that a portion by combining with the carbon formed 
cyanogen, which would pass off or be converted into hydr 
acid, and the latter unite itself to the potash. But upon experi- 
