51 



With a thoroughly washed pipette draw up exactly 1 cc. of urine 

 and pass the pipette through the bulb of the ureoineter as far as it 

 will go in the bend. Compress the bulb of the pipette gently and 

 steadily. The urine will rise through the hypobromite, and the 

 urea instantly decompose, giving off nitrogen gas. AVithdraw 

 the pipette after the urine has been expelled, taking care not to 

 press the bulb hard enough to drive the air out with the urine, 

 and read the volume of gas, after allowing the froth to subside. 



Each division mark on the ureometer indicates 0.001 gram 

 of urea in 1 cc. of urine. The quantity of urea voided in 24 hours 

 is ascertained by multiplying the result of the test by the number 

 of cc. of urine passed during that period. 



The COo resulting from the decomposition of the urea is ab- 

 sorbed by the excess of soda in the hypobromite solution, and 

 nitrogen is evolved. 37.1 cc. of moist nitrogen gas measured 

 under the ordinary conditions of experiment may be taken to rep- 

 resent 0.1 gram of urea. 1 gram of urea corresponds to 13.72 

 grams of muscular tissue. 



Albumin. Esbach's Method. Fill the 

 tube with the suspected urine to the letter U, 

 then add the reagent to the letter R. (The 

 reagent is made by mixing 10 grams of picric 

 dcid and 20 grams of citric acid and adding 

 enough w^ater to make 1 liter. It is said that 

 acetic acid may be substituted for the citric 

 with as good results). Invert the tube a 

 number of times so that the contents may be 

 thoroughly mixed. Close the tube tightly 

 with the rubber stopper and set aside for 24 

 hours, after which the amount of dried albu- 

 min in one liter of urine can be read in grams 

 on the tube. The percentage is obtained by 

 dividing by ten. Thus, if the coagulum 

 stands at 3, the urine contains three parts of 

 albumin per thousand, or 0.3%. If the albu- 

 min is very abundant (above four) the urine 



should be diluted to obtain an accurate result. 



0.5 per thousand of albumin cannot be 



mated by this method. 



u^^ 



Fig. 14. 

 Esbach's 

 Albumin- 

 ometer. 



Less than 

 accurately esti- 



