NEW NITROMETER FOR CLINICAL ESTIMATION OF UREA 437 
The error of volume arising from the superincumbent fluid is thus so small that 
it may safely be neglected for clinical work, and the reading given at once taken as 
the volume of nitrogen for 1 c.c. of urine, or for the quantity injected, whatever 
that may be. 
Having read off, withdraw the stopper. The indicating fluid falls back to its 
original level. Remove the used-up solution with the pipette. Cleanse, recharge, 
adjust, and so on, any number of times, each time with fresh hypobromite 
solution. 
It takes very little time to do any observation, and having used it once or twice 
it is quite easy with one tube of bromine or one ounce of fresh solution to do 
several urines (eight or nine), and it more than 2 c.c. be injected for a charge it is 
easy, without withdrawing the stopper, to inject a second c.c. of urine almost imme- 
diately with a view of corroborating the previous reading. 
There is no trouble arising from the froth. It is possible to read off* at once. 
Indeed, the character of the froth becomes a very delicate test for albumin in the 
urine. In dealing with albuminous urines Southall's is hors de combat. 
After an experience of several months one has had no breakages of glass. The 
glass may be made strong enough to withstand almost any reasonable strain, and as the 
instrument stands upright bound by one or more ordinary india-rubber bands to the 
column of the stand, it is never loose, and, therefore, the danger of being knocked 
about is reduced to a minimum. The floor of the wooden stand is about one foot 
square, and the height of the central fluted column is little over a foot high, so this 
gives a condition of very stable equilibrium and a small platform on which to rotate 
the tube and place instruments. It will protect an ordinary table, and may be 
moved about from one table to another. For a series of comparative estimations one 
has found this nitrometer especially useful. 
The glass work has been very carefully and efficiently done by Mr. Grigioni, 
of Mersey Street, Liverpool. 
D 1 
