SHORT REPORTS FROM THE CHEMICAL LABORATORY 
OF TRINITY COLLEGE, DUBLIN. 
BY 
J. EMERSON REYNOLDS, M.D., 
Professor of Chemistry, University of Dublin. 
NOV. 
On the Rapid Estumation of Urea. 
(Read March 19th, 1877.) 
A DISTINGUISHED physician, who wished to make frequent deter- 
minations of the urea daily excreted by a patient, requested me 
to devise a method which would enable him to make the desired 
estimation—(q) rapidly, (b) with sufficient accuracy for ordinary 
clinical purposes, (c) with simple and easily constructed apparatus, 
and (d) without the use of a balance or of any measuring vessels 
other than the fluid ounce and minim measures which a medical 
man is in the habit of employing. 
This interesting practical problem was solved in the manner 
I shall presently describe, and the results obtained by the use of 
the method devised have been so satisfactory as to lead me to 
expect that it may be found generally useful where a high degree 
of accuracy is not desired. 
Before concluding this paper, however, I propose to doatritie a 
less simple plan for the estimation of urea than that just referred 
to; but onewhich is capable of affording results of greater precision. 
In both the methods mentioned I take advantage of the now 
well-known reaction of sodic hypobromite with urea. When a 
strongly alkaline solution of sodic hypobromite is added to a 
liquid containing urea, the latter suffers rapid decomposition 
into water, carbonic anhydride, and pure nitrogen gas. The 
carbonic anhydride is not evolved as gas but is absorbed, with 
formation of sodic carbonate, by the free alkali of the liquid 
used to effect decomposition; the nitrogen is evolved in the 
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